[Federal Register Volume 62, Number 201 (Friday, October 17, 1997)]
[Proposed Rules]
[Pages 54160-54308]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-27020]
[[Page 54159]]
_______________________________________________________________________
Part II
Department of Labor
_______________________________________________________________________
Occupational Safety and Health Administration
_______________________________________________________________________
29 CFR Part 1910
Occupational Exposure to Tuberculosis; Proposed Rule
Federal Register / Vol. 62, No. 201 / Friday, October 17, 1997 /
Proposed Rules
[[Page 54160]]
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DEPARTMENT OF LABOR
Occupational Safety and Health Administration
29 CFR Part 1910
[Docket No. H-371]
RIN 1218-AB46
Occupational Exposure to Tuberculosis
AGENCY: Occupational Safety and Health Administration (OSHA), Labor
ACTION: Proposed rule and notice of public hearing.
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SUMMARY: The Occupational Safety and Health Administration is proposing
a health standard, to be promulgated under section 6(b) of the
Occupational Safety and Health Act of 1970, 29 U.S.C. 655, to control
occupational exposure to tuberculosis (TB). TB is a communicable,
potentially lethal disease that afflicts the most vulnerable members of
our society: the poor, the sick, the aged, and the homeless. As many as
13 million U.S. adults are presently believed to be infected with TB;
over time, more than 1 million of these individuals may develop active
TB disease and transmit the infection to others. TB remains a major
health problem with 22,813 active cases reported in the U.S. in 1995. A
number of outbreaks of this disease have occurred among workers in
health care settings, as well as other work settings, in recent years.
To add to the seriousness of the problem, some of these outbreaks have
involved the transmission of multidrug-resistant strains of
Mycobacterium tuberculosis, which are often fatal. Although it is the
responsibility of the U.S. Public Health Service to address the problem
of tuberculosis in the general U.S. population, OSHA is solely
responsible for protecting the health of workers exposed to TB as a
result of their job.
OSHA estimates that more than 5 million U.S. workers are exposed to
TB in the course of their work: in hospitals, homeless shelters,
nursing homes, and other work settings. Because active TB is endemic in
many U.S. populations, including groups in both urban and rural areas,
workers who come into contact with diseased individuals are at risk of
contracting the disease themselves. The risk confronting these workers
as a result of their contact with TB-infected individuals may be as
high as 10 times the risk to the general population. Although the
number of reported cases of active TB has slowly begun to decline after
a resurgence between 1985-1992, 16 states reported an increase in the
number of TB cases in 1995, compared with 1994. Based on a review of
the data, OSHA has preliminarily concluded that workers in hospitals,
nursing homes, hospices, correctional facilities, homeless shelters,
and certain other work settings are at significant risk of incurring TB
infection while caring for their patients and clients or performing
certain procedures. To reduce this occupational risk, OSHA is proposing
a standard that would require employers to protect TB-exposed employees
by means of infection prevention and control measures that have been
demonstrated to be highly effective in reducing or eliminating job-
related TB infections. These measures include the use of respirators
when performing certain high hazard procedures on infectious
individuals, procedures for the early identification and treatment of
TB infection, isolation of individuals with infectious TB in rooms
designed to protect those in the vicinity of the room from contact with
the microorganisms causing TB, and medical follow-up for occupationally
exposed workers who become infected. OSHA has preliminarily determined
that the engineering, work practice, and administrative controls,
respiratory protection, training, medical surveillance, and other
provisions of the proposed standard are technologically and
economically feasible for facilities in all affected industries.
DATES: Written comments on the proposed standard must be postmarked on
or before December 16, 1997 and notices of intention to appear at the
informal rulemaking hearings must be postmarked on or before December
16, 1997.
Parties requesting more than 10 minutes for their presentation at
the hearings and parties submitting documentary evidence at the hearing
must submit the full text of their testimony and all documentary
evidence no later than December 31, 1997.
The informal public hearings will begin at 10:00 a.m. on the first
day of hearing and at 9:00 a.m. on each succeeding day. The informal
public hearings will be held in Washington, D.C. and are scheduled to
begin on February 3, 1998.
ADDRESSES: Hearings will be held in the Auditorium of the U.S.
Department of Labor (Frances Perkins Building), 200 Constitution
Avenue, NW, Washington, D.C. Subsequent additional informal public
hearings will be held in other U.S. locations. A Federal Register
notice will be issued upon determination of the locations and dates of
these hearings.
Comments on the proposed standard, Notices of Intention to Appear
at the informal public hearings, testimony, and documentary evidence
are to be submitted in quadruplicate to the Docket Officer, Docket No.
H-371, Room N-2625, U.S. Department of Labor, 200 Constitution Ave.,
NW, Washington, DC 20210, telephone (202) 219-7894. Comments of 10
pages or fewer may be transmitted by fax to (202) 219-5046, provided
the original and three copies are sent to the Docket Officer
thereafter. The hours of operation of the Docket Office are 10:00 a.m.
until 4:00 p.m.
Written comments, Notices of Intention to Appear at the informal
rulemaking hearings, testimony, documentary evidence for the hearings,
and all other material related to the development of this proposed
standard will be available for inspection and copying in the Docket
Office, Room N-2625, at the above address.
FOR FURTHER INFORMATION CONTACT: Bonnie Friedman, Office of Information
and Consumer Affairs, Occupational Safety and Health Administration,
Room N-3647, U.S. Department of Labor, 200 Constitution Ave., NW,
Washington, DC 20210, Telephone (202) 219-8148, FAX (202) 219-5986.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Introduction
II. Pertinent Legal Authority
III. Events Leading to the Proposed Standard
IV. Health Effects
V. Preliminary Risk Assessment
VI. Significance of Risk
VII. Preliminary Economic and Regulatory Flexibility Analysis
VIII. Unfunded Mandates
IX. Environmental Impact
X. Summary and Explanation of the Proposed Standard
XI. Public Participation--Notice of Hearing
XII. Authority and Signature
XIII. The Proposed Standard
References to the rulemaking record are in the text of the
preamble. References are given as ``Ex.'' followed by a number to
designate the reference in the docket. For example, ``Ex. 1'' means
exhibit 1 in the Docket H-371. This document is a copy of the petition
for a permanent standard filed by the Labor Coalition to Fight TB in
the Workplace on August 25, 1993. A list of the exhibits and copies of
the exhibits are available in the OSHA Docket Office.
[[Page 54161]]
I. Introduction
The preamble to the Proposed Standard for Occupational Exposure to
Tuberculosis discusses the events leading to the development of the
proposed standard, the health effects of exposure to tuberculosis, and
the degree and significance of the risk. An analysis of the
technological and economic feasibility of the proposal and an
explanation of the rationale supporting the specific provisions of the
proposed standard are also included.
Public comment on all matters discussed in this notice and all
other relevant issues is requested for the purpose of assisting OSHA in
the development of a new standard for occupational exposure to
tuberculosis.
A. Issues
OSHA requests comment on all relevant issues discussed in this
preamble, including the health effects, risk assessment, significance
of risk determination, technological and economic feasibility and
requirements that should be included in the final standard. OSHA is
especially interested in responses, supported by evidence and reasons,
to the following questions. This list is provided to assist persons in
formulating comments, but is not intended to be all inclusive or to
indicate that participants need to respond to all issues or follow this
format. Please give reasons for your answers and provide data when
available.
Specific issues of concern to OSHA are the following:
Health Effects
1. What, if any, additional studies or case reports on TB should be
included in the health effects analysis?
2. Is there information that will provide data for estimating the
rise in Multidrug-resistant TB (MDR-TB)? Is the rise in MDR-TB a
serious threat?
Risk Assessment
1. Are there alternative risk assessment methodologies available?
What are they? Are there other studies available that would be useful
for assessing risk?
2. Are there factors other than or in addition to the ones OSHA has
chosen that would be useful in estimating the background risk for TB?
Technological and Economic Feasibility
1. Are OSHA's estimates of the numbers and types of workers
currently exposed to M. tuberculosis reasonable? If not, please provide
estimates of the number of workers currently at risk and the percentage
of the total workforce these workers represent, by industry.
2. Are OSHA's estimates of controlled access rates (i.e., the
percentage of workers currently at risk who would remain at risk after
employers minimize the number of workers exposed to individuals with
suspected or confirmed infectious TB) reasonable? If the number of
workers exposed to individuals with suspected or confirmed infectious
TB is minimized, by what percentage could the number of workers at risk
be reduced in each affected industry? In each industry, what are the
job categories that would continue to be occupationally exposed?
3. Are OSHA's estimates of the numbers of affected establishments
reasonable? If not, please provide estimates of the number of affected
establishments, by industry.
4. Are OSHA's estimates of occupational and job turnover rates
reasonable? If not, please provide estimates of turnover rates for each
of the affected industries.
5. Under what conditions would social work, social welfare
services, teaching, law enforcement or legal services need to be
provided to individuals identified as having suspected or confirmed
infectious TB? What, if any, procedures could not be postponed until
such individuals are determined to be noninfectious? How many workers
in each of these categories may need to have contact with individuals
with suspected or confirmed infectious TB under these conditions?
6. Using the proposed definition of ``suspected infectious TB,''
how many individuals with suspected infectious TB are likely to be
encountered for every confirmed infectious TB case in each of the
covered industries?
7. Are OSHA's estimates of the average number of suspected or
confirmed infectious TB cases that would be transferred, per
establishment in each industry, reasonable? If not, on average, how
many TB cases per facility in each of the affected industries would be
transferred?
8. How are individuals with suspected infectious TB transferred to
establishments with AFB isolation facilities? Who pays for the
transport of such cases, particularly for individuals transferred from
homeless shelters? OSHA solicits comment on the feasibility of
temporary AFB isolation facilities in homeless shelters and on methods
that could be used to temporarily isolate individuals with suspected or
confirmed infectious TB in homeless shelters.
9. Of the suspected infectious TB cases referred to hospitals from
other facilities, how many are immediately ruled out without needing to
be isolated?
10. Are OSHA's estimates of the number of necessary AFB isolation
rooms reasonable? Are existing AFB isolation rooms reasonably
accessible to facilities that transfer individuals with suspected or
confirmed infectious TB?
11. What types of respirators are currently being used to protect
workers against occupational exposure to M. tuberculosis?
12. Which of the NIOSH-approved N95 respirators meet all of the
proposed criteria, including fit testing and fit checking criteria?
13. Are OSHA's estimates of respirator usage rates reasonable? For
each of the covered industries, how often could respirators meeting the
proposed requirements be reused and still maintain proper working
condition? How often, on average, would respirators need to be
replaced? Please specify the type of respirator.
14. OSHA has assumed, in its Preliminary Economic Analysis, that
hospitals will have licensed health care professionals on-site to
perform the medical procedures that would be required by the proposed
rule, and that in the other industries, employees will have to travel
off-site to receive the medical procedures. Which of the other affected
industries typically have licensed health care professionals on site
who could perform the required medical procedures? If employers were
allowed two weeks to provide the medical procedures, rather than being
required to provide them prior to initial assignment to jobs with
occupational exposure, will it be less likely that employees will have
to travel off site to receive these tests/procedures? What would the
costs be if employees travel off-site for these tests/procedures?
15. Are OSHA's estimates of baseline compliance reasonable? If not,
what types of controls are currently in place to protect workers
against occupational exposure to M. tuberculosis, and what proportion
of facilities in each of the affected industries currently are using
such controls?
16. For facilities that have implemented controls to protect
workers against occupational exposure to M. tuberculosis, how effective
have such controls been in reducing the transmission of TB?
17. OSHA's Initial Regulatory Flexibility Analysis assesses the
impacts of the proposed standard on small entities using the Small
Business Administration's (SBA) size standards.
[[Page 54162]]
In addition, OSHA analyzed the impacts of the proposed standard on
entities employing fewer than 20 workers. Are these definitions
appropriate for the covered industries? If not, how should small
entities be defined for each industry?
18. The SBA defines small government jurisdictions as ``governments
of cities, counties, towns, townships, villages, school districts, or
special districts with populations of less than 50,000.'' OSHA requests
comment on the number of such small government jurisdictions.
19. Some parties have suggested that OSHA should allow the use of
the CDC guidelines as an alternative to the proposed rule. However,
OSHA believes that the CDC guidelines are not written in a regulatory
format that would allow OSHA's Compliance Safety and Health Officers
(CSHOs) to determine whether or not an employer is in compliance with
the Guidelines. Others have suggested that OSHA could judge compliance
with the guidelines by determining the number or rate of skin test
conversions at the employer's facility. OSHA does not believe that
smaller facilities have an adequate population for trends in test
conversions to have any statistical validity. OSHA welcomes suggestions
on any methods of making the CDC guidelines an enforceable alternative
to an OSHA regulation or methods of measuring performance that could be
applied across all types and sizes of facilities.
20. Because of the limited availability of data, OSHA characterized
the risk in many sectors as similar to that in hospitals, and less than
that documented in nursing homes and home health care. OSHA welcomes
industry-specific data on test conversion rates or active case rates.
21. OSHA is unable to determine the effectiveness of specific
elements of an effective infection control program in hospitals. OSHA
welcomes any evidence on the relative effectiveness of individual
elements in such programs, such as the identification and isolation of
suspect cases, the use of engineering controls, the use of respirators,
and employee training.
22. OSHA based its estimate of the effectiveness of infection
control programs in other sectors on studies of the effectiveness of
such programs in hospitals. OSHA welcomes any data concerning the
effectiveness of OSHA's proposed infection prevention measures, or of
other alternative infection control measures, in sectors other than
hospitals.
23. SBREFA Panel members suggested a number of alternative
approaches to the regulation. OSHA believes that it has at least
partially adopted a number of these approaches. OSHA welcomes comments
and suggestions on these approaches and the extent to which OSHA should
further adopt them:
Cooperative initiatives, such as expanding OSHA's current
cooperative initiative with JCAHO;
A federal-state government public health partnership to
develop guidelines in various industry sectors;
Performance standards developed with the assistance of
federal, state, and local government, and labor and industry
stakeholders;
Separate approaches for the health and non-health
industries (the approach for the health industries could be keyed to
existing industry standards and that for non-health industries to
guidelines);
Different levels of compliance requirements for different
industries, depending on their expertise, resources, and risk;
Less stringent trigger mechanisms for the more burdensome
portions of the standard; and
Separate standards for each affected industry.
24. OSHA is proposing to include homeless shelters in the Scope of
the standard. During the informal public hearings, OSHA intends to
schedule a special session for participants to present additional
information on homeless shelters. Also, OSHA is conducting a special
study of the homeless shelter sector. The information gathered in the
study will be placed in the docket for public comment. OSHA welcomes
comment on any of the topics this study will cover including:
Percentage of homeless persons that would meet OSHA's
definition of a suspected infectious TB case (A breakdown of which
symptoms are particularly common will help OSHA construct the best
definition);
Turnover among the homeless who use shelters;
Employee turnover in homeless shelters;
Trends in the number of homeless persons served in
shelters.
Criteria currently used by some homeless shelters to
identify suspected infectious TB cases;
Current practices used in homeless shelters to address TB
hazards so that baseline compliance with the proposed standard can be
determined. Of particular concern to OSHA are:
--Methods of isolation; and
--How suspected TB cases are handled.
Feasibility of hospitals providing cards to the homeless
indicating TB skin test status;
Number of TB skin test conversions and active cases among
the homeless and homeless shelter employees;
Types of benefits offered to homeless shelter employees
(e.g., health insurance);
Economic feasibility:
--Costs of running a shelter;
--Revenue sources;
--How costs are accommodated as the number of homeless persons served
increases; and
--Opportunities for cost pass-through;
Number, location and types (e.g., family-oriented, walk-
in, all-male) of homeless shelters;
Number or proportion of homeless shelter workers who are
unpaid volunteers; and
The OSH Act applies to employees, not bona fide
volunteers. However, OSHA understands that some states may, as a matter
of law, require facilities to provide volunteers with protections
established by OSHA standards. OSHA is seeking information on:
--Economic impacts in such states of covering volunteers (e.g., how
costs would be handled, cost pass-through); and
--Protections currently offered to volunteers.
25. In what states, if any, do employers provide volunteers in the
sectors affected by this proposed standard with the same protections as
they provide to employees? How many volunteers might be affected by
such requirements?
26. OSHA is concerned that medical removal protection and medical
treatment of active cases of TB may have significant economic impacts
on small firms that have an employee with an active case of TB. Is
there any form of insurance available for covering the costs of medical
removal protection or medical treatments required by the OSHA standard?
Should OSHA consider phasing-in these provisions of the standard?
27. OSHA believes that substance abuse treatment centers,
particularly in-patient treatment centers, normally have entry
procedures that may include medical examinations. OSHA solicits
comments on entry procedures for substance abuse treatment programs,
the extent to which these entry procedures now include medical
examinations, and the extent to which these examinations now include
and examination for TB symptoms.
28. OSHA requests comment on the effects of extended compliance
phase-in dates for the proposed requirements,
[[Page 54163]]
particularly for respirators, for small businesses and facilities
relying on charitable and/or Medicare and Medicaid funding.
29. OSHA requests comment on all assumptions and estimates used in
developing the Preliminary Economic Analysis. Please provide reasons
and data to support suggested changes to the assumptions and estimates.
30. The World Health Organization (WHO) has launched an initiative
to reduce active TB through the use of multi-drug therapy and using
directly observed therapy. OSHA solicits comment on whether it should
revise its risk assessment or any of its benefits estimates as a result
of this initiative.
31. OSHA requests comment on the number of affected facilities that
are tribally-operated, by industry.
General
1. A number of provisions in the proposed standard are triggered by
the identification of an individual as having either ``suspected
infectious tuberculosis'' or ``confirmed infectious tuberculosis.'' Of
these provisions, are there some that should be triggered only once an
individual has been identified as having ``confirmed infectious
tuberculosis?'' If so, which provisions and why?
2. A number of the proposed standard's provisions require
compliance or performance on an annual basis, e.g., reviews of the
exposure control plan, the biosafety manual for laboratories, and the
respiratory protection program; certification of biological safety
cabinets; fit testing or a determination of the need for fit testing of
respirators; medical histories, TB skin tests; and training. In
addition, certain requirements must be performed on a semi-annual
basis, e.g., inspection and performance monitoring of engineering
controls, verification of air flow direction in laboratories, and, in
some instances, TB skin testing. How can OSHA reduce the aggregate
burden of these requirements, particularly in small entities, while
still providing equal protection to employees? Of these annual and
semi-annual provisions, which, if any, should be performed less
frequently? Why and at what frequency? Which of these provisions, if
any, should be performed more frequently? Why and at what frequency?
Scope
1. Is there information demonstrating risk of TB transmission for
employees in work settings other than those included in the scope?
Should OSHA, for example, expand the scope of this standard to cover
all or some offices of general practitioners or dentists and if so,
how? Should OSHA expand the scope to cover all teachers?
2. Are there provisions of the standard with which emergency
medical services, home health care, and home-based hospice care
employers cannot comply because their employees are at temporary work
settings over which the employer has little or no control? If so, what
are those provisions and why would an employer be unable to comply with
them?
3. In covering only long-term care facilities for the elderly, is
OSHA excluding similar facilities where there is increased risk of
transmission of TB? If so, what are these facilities? Should OSHA
include long-term care populations in addition to the elderly, such as
long-term psychiatric care facilities? If so, what are these
populations?
4. OSHA is proposing that employers provide medical management and
follow-up for their employees who work in covered work settings, but
who are not occupationally exposed, when they have an exposure incident
resulting from an engineering control failure or similar workplace
exposure. Is this the best way of assuring such employees receive
medical management and follow-up?
5. OSHA is covering employees who have occupational exposure in
covered work settings yet are not employees of the work setting (e.g.,
physician employed by another employer with hospital privileges, who is
caring for a TB patient in the hospital). Can this be made more clear?
6. OSHA has proposed that facilities offering treatment for drug
abuse be covered in the scope of the standard. Is coverage of such
facilities appropriate? What factors unique to facilities that offer
treatment for drug abuse would make compliance with the provisions of
this proposed standard infeasible (e.g., would complying with certain
provisions of the standard compromise the provision of services at
facilities that offer treatment for drug abuse)?
Application
1. OSHA has proposed that an employer covered under the standard
(other than an operator of a laboratory) may claim reduced
responsibilities if he or she can demonstrate that his or her facility
or work setting: (1) Does not admit or provide medical services to
individuals with suspected or confirmed infectious TB; (2) has had no
case of confirmed infectious TB in the past 12 months; and (3) is
located in a county that, in the past 2 years, has had 0 cases of
confirmed infectious TB reported in one year and fewer than 6 cases of
confirmed infectious TB reported in the other year. Are there
alternative methods that can be used to assure protection of employees
in areas where infectious TB has not recently been encountered?
Exposure Control Plan
1. OSHA has proposed that the employer's exposure control plan
contain certain policies and procedures. What, if any, policies and
procedures should be added to the plan?
2. The proposed standard requires exposure incidents and skin
conversions to be investigated, but does not require aggregate data
regarding employee conversions to be collected and analyzed. Would the
collection and analysis of aggregate data provide benefits beyond those
provided by investigating each individual exposure incident or
conversion? Why or why not? If aggregate data collection and analysis
were required, what type of analysis should be required, at what
analytical endpoint should employer action be required, and what should
that action be?
3. OSHA has set forth the extent of responsibility for transfer of
individuals based upon the type of work setting where such individuals
are encountered. What are current practices regarding transfer of
individuals with suspected or confirmed infectious TB in the work
settings covered by the proposal?
Work Practices and Engineering Controls
1. Is OSHA's time limit of 5 hours following identification for
transferring an individual with suspected or confirmed infectious TB to
another facility or placing the individual into AFB isolation
appropriate? If not, what is the maximum amount of time that an
individual should be permitted to await transfer or isolation in a
facility before the employer must implement the other provisions of the
proposed standard?
2. OSHA has considered requiring facilities that encounter 6 or
more individuals with confirmed infectious TB within the past 12 months
to provide engineering controls in intake areas where early
identification procedures are performed (e.g., emergency departments,
admitting areas). Should this be a requirement? Are there types of
controls, engineering or otherwise, that would be effective in
controlling transmission in intake areas? Would the trigger of 6
individuals with confirmed infectious TB be appropriate?
[[Page 54164]]
3. Are there methods other than smoke trail testing and continuous
monitors that would be effective for verifying negative pressure in AFB
isolation rooms or areas?
4. OSHA is requiring engineering controls to be inspected and
performance monitored every 6 months. Is this frequency appropriate?
5. OSHA is allowing exhaust air from AFB isolation rooms or areas
where M. tuberculosis may be aerosolized that cannot feasibly be
discharged directly outside to be HEPA-filtered and recirculated back
into general ventilation. Is permitting such recirculation appropriate?
If used, should there be any requirements to detect system failure?
6. OSHA is permitting stand-alone HEPA filter units to be used as a
primary control measure. Is this appropriate? What, if any, methods
other than ventilation and filtration can provide consistent
protection?
7. Should ambulances that have carried an individual with suspected
or confirmed infectious TB be required to be ventilated for a specific
period of time or in a particular way before allowing employees to
enter without a respirator? What engineering controls are available for
ambulances?
Laboratories
1. The standard does not require labeling of laboratory specimens.
Should OSHA require that laboratory specimens be labeled within the
facility or when specimens are being shipped? If so, what should the
label contain? Are there other agencies that require these specimens be
labeled? What are these agencies and what is required?
2. OSHA has attempted to incorporate the CDC/NIH recommendations
given in ``Biosafety in Microbiological and Biomedical Laboratories''
into the standard. Do any provisions need to be added in order for
employees in clinical and research laboratories to be fully protected
against exposures to M. tuberculosis?
Respirators
1. OSHA is requiring employees who are transporting an unmasked
individual with suspected or confirmed infectious TB within a facility
to wear a respirator. Is this appropriate? How often would an
individual with suspected or confirmed infectious TB be transported
unmasked through a facility? Under what circumstances would it be
infeasible to mask such an individual? What other precautions should be
taken when transporting such an individual who is not masked?
2. OSHA is requiring that maintenance personnel use respiratory
protection during maintenance of air systems or equipment that may
reasonably be anticipated to contain aerosolized M. tuberculosis. When
would it be necessary to access such an air system at the time it was
carrying air that may contain aerosolized M. tuberculosis? Should OSHA
require that such air systems be purged and shut down whenever these
systems are accessed for maintenance or other procedures?
3. OSHA has received information that the use of certain kinds of
respirators in helicopters providing emergency medical services may
hamper pilot communication. Have other air ambulance services
encountered this problem? Does this problem exist when the employee is
using a type N95 respirator or other types of respiratory protection
such as powered air purifying respirators? What other infection control
or industrial hygiene practices could be implemented to minimize
employee exposure in these circumstances?
4. The CDC states that there may be selected settings and
circumstances (e.g., bronchoscopy on an individual with suspected or
confirmed infectious TB or an autopsy on a deceased individual
suspected of having had active TB at the time of death) where the risk
of transmission may be such that increased respiratory protection such
as that provided by a more protective negative-pressure respirator or a
powered air purifying respirator may be necessary. Are there
circumstances where OSHA should require use of a respirator that is
more protective than a type N95 respirator? If so, what are the
circumstances and what type of respiratory protection should be
required?
5. OSHA is proposing that respirators be fit-tested annually, which
is consistent with general industrial hygiene practice, or, in lieu of
an annual fit test, that employees have their need to receive the
annual fit test be evaluated by the physician or other licensed health
care professional, as appropriate. For the circumstances and conditions
regulated by this standard, will the evaluation provide enough ongoing
information about the fit of a respirator to be an adequate substitute
for fit testing? Should OSHA require that an actual fit test be
performed periodically? If so, at what frequency?
6. OSHA has not included any provisions regarding the use of
supplied air respirators. Are there circumstances in which supplied air
respirators would be used to protect against M. tuberculosis? Should
OSHA include provisions addressing supplied air respirators in the
standard?
7. OSHA is permitting the reuse of disposable respirators provided
the respirator does not exhibit excessive resistance, physical damage,
or any other condition that renders it unsuitable for use. Will the
respirators continue to protect employees throughout the reuse period?
8. In the proposed standard for TB, OSHA has included separate
provisions for all aspects of a respiratory protection program for
tuberculosis. What other elements might need to be included? Which
respiratory protection provisions, if any, are not appropriate for
protection against TB? Please provide reasons and data to support
inclusion or exclusion of particular provisions.
Medical Surveillance
1. Should any provisions be added to the Medical Surveillance
program?
2. OSHA has not required that physical exams be included as part of
the baseline evaluation. Is there information that is essential to
medical surveillance for TB that can only be learned from a baseline
physical exam?
3. OSHA is specifying tuberculin skin testing frequencies for
employees with negative skin tests. Should tuberculin skin testing be
administered more or less frequently? Are there other ways to determine
the frequency of tuberculin skin testing?
4. OSHA is proposing that employees entering AFB isolation rooms or
areas be skin tested every 6 months. However, employees providing home
health care, home care, and home-based hospice care are to be skin
tested annually. Employees entering the home of an individual who has
suspected or confirmed infectious TB may have the same potential for
exposure to aerosolized M. tuberculosis as employees who enter an
isolation room. In light of this, should employees providing care to
individuals with suspected or confirmed infectious TB in private homes
be skin tested every 6 months?
5. OSHA is requiring that all tuberculin skin testing be
administered, read, and interpreted by or under the supervision of a
physician or other licensed health care professional, as appropriate,
according to current CDC recommendations. Should OSHA require specific
training for individuals who are administering, reading, and
interpreting tuberculin skin tests? If so, what type of training should
be required?
[[Page 54165]]
6. Should OSHA require a declination form for employees who do not
wish to undergo tuberculin skin testing?
7. OSHA is including Medical Removal Protection (MRP) provisions
for employees who are unable to wear respiratory protection or who
contract infectious tuberculosis. Are there additional provisions that
need to be included? What remedies are available to employees in states
where worker compensation system do not consider occupational TB a
compensable disease? What benefits are provided to workers who are
unable to wear a respirator?
8. OSHA is requiring that employees who must wear a respirator be
provided a face-to-face determination of their ability to wear the
respirator. Does this determination need to be made through a medical
evaluation or would the use of an appropriately designed questionnaire
be adequate? What would be the advantages and disadvantages of relying
on a questionnaire to make this determination? Are there sample
questionnaires that have proven to be effective for determining an
employee's ability to wear a respirator?
9. OSHA has drafted Medical Surveillance, paragraph (g), to explain
first who must be provided with the protections listed in the paragraph
and how the surveillance is to be administered and secondly, in
paragraphs (g)(2), Explanation of Terms, and (g)(3), Application, how
the general medical terms are to be construed to meet the standard and
in what instances the medical examinations or tests are to be offered.
The Agency realizes that there is some repetition in these paragraphs
and seeks comment on whether there might be a better way to list the
requirements.
Communication of Hazards and Training
1. OSHA is requiring that signs for isolation rooms and areas bear
a ``STOP'' Sign and the legend ``No Admittance Without Wearing A Type
N95 or More Protective Respirator.'' Is there another sign that would
assure patient confidentiality while providing adequate notification of
the hazard and the necessary steps to minimize the hazard for employees
who may be inadvertently exposed?
2. OSHA is requiring that ducts be labeled ``Contaminated Air--
Respiratory Protection Required.'' Should OSHA require that duct labels
also include the ``STOP'' sign?
3. Is the labeling of ducts carrying air that may contain
aerosolized M. tuberculosis (e.g., from isolation rooms and areas,
labs) at all access points feasible? What, if any, equally protective
alternative exists to permanent labeling in situations where an exhaust
duct from a room may or may not be carrying air containing aerosolized
M. tuberculosis (e.g., the exhaust duct would only be carrying
aerosolized M. tuberculosis when an individual with infectious TB is
being isolated in the room)?
Dates
1. OSHA has proposed that very small businesses with fewer than 20
employees be given an additional 3 months to comply with the standard's
engineering control provisions (i.e., the start-up date for engineering
controls for small businesses would be 270 days from the Effective Date
of the standard). Are there other requirements of the proposed standard
(e.g., respiratory protection) for which very small businesses should
be given additional time to come into compliance? If so, for which
provisions would they need additional time and why? Are 20 employees an
appropriate cut-off for this purpose? Are there other employers that
may need extended time to achieve compliance?
Definitions
1. A number of provisions in the standard are triggered by the
identification of an individual as having ``suspected infectious
tuberculosis.'' Under the definition of ``suspected infectious
tuberculosis'', OSHA has proposed criteria that the Agency believes are
the minimum indicators that, when satisfied by an individual, require
an employer to consider that the individual may have infectious
tuberculosis. Are there other criteria that should be included in this
definition?
2. Coverage of an employee under the standard is based upon the
definition of ``occupational exposure.'' Similar to OSHA's Bloodborne
Pathogens standard, occupational exposure is dependent upon reasonable
anticipation of contact with an individual with suspected or confirmed
infectious tuberculosis or with air that may contain aerosolized M.
tuberculosis. Are there additions that could be made to this definition
that would help employers determine which of their employees are
occupationally exposed?
3. OSHA has proposed requirements for research laboratories that
differ from those of clinical laboratories. The standard includes
definitions of ``research laboratory'' and ``clinical laboratory'' to
assist the employer in differentiating between these two types of
laboratory. Do the definitions clearly differentiate between these two
types of laboratories? Should such a distinction be made? Are there any
modifications that should be made to these definitions?
B. Information Collection Requirements
This proposed Tuberculosis standard contains collections of
information that are subject to review by the Office of Management and
Budget (OMB) under the Paperwork Reduction Act of 1995 (PRA'95), 44
U.S.C. 3501 et seq. and the regulation at 5 CFR Sec. 1320. PRA'95
defines collection of information to mean, ``the obtaining, causing to
be obtained, soliciting, or requiring the disclosure to third parties
or the public of facts or opinions by or for an agency regardless of
form or format.'' [44 U.S.C. Sec. 3502(3)(A)].
The title, description of the need for and proposed use of the
information, summary of the collections of information, description of
the respondents, and frequency of response of the information
collection are described below with an estimate of the annual cost and
reporting burden, as required by 5 CFR Sec. 1320.5(a)(1)(iv) and
Sec. 1320.8(d)(2). Included in the estimate is the time for reviewing
instructions, gathering and maintaining the data needed, and completing
and reviewing the collection of information.
OSHA invites comments on whether the proposed collection of
information:
(1) Ensures that the collection of information is necessary for the
proper performance of the functions of the agency, including whether
the information will have practical utility;
(2) Estimates the projected burden accurately, including whether
the methodology and assumptions used are valid;
(3) Enhances the quality, utility, and clarity of the information
to be collected; and
(4) Minimizes the burden of the collection of information on those
who are to respond, including through the use of appropriate automated,
electronic, mechanical, or other technological collection techniques or
other forms of information technology, e.g., permitting electronic
submissions of responses.
Title: Tuberculosis 29 CFR 1910.1035.
Description: The proposed Tuberculosis (TB) Standard is an
occupational safety and health standard that will prevent or minimize
occupational exposure to TB. The standard's information collection
requirements are essential components that will protect employees from
occupational exposure. The information will be used by employers and
employees to implement the protection
[[Page 54166]]
required by the standard. OSHA compliance officers will use some of the
information in their enforcement of the standard.
Respondents: The respondents are employers whose employees may have
occupational exposure in the following settings: hospitals; long-term
care facilities for the elderly; correctional facilities and other
facilities that house inmates or detainees; hospices; shelters for the
homeless; facilities that offer treatment for drug abuse; facilities
where high hazard procedures are performed; and laboratories that
handle specimens that may contain M. tuberculosis or process or
maintain the resulting cultures, or perform related activity that may
result in the aerosolization of M. tuberculosis.
Also, occupational exposure occurring during the provision of
social work, social welfare services, teaching, law enforcement or
legal services would be covered if the services are provided in the
work settings previously mentioned, or in residences, to individuals
who are in AFB isolation or are segregated or otherwise confined due to
having suspected or confirmed infectious TB. Respondents also include
employers whose employees are occupationally exposed during the
provision of emergency medical services, home health care and home-
based hospice care. Approximately 101,875 employers will be responding
to the standard.
Total Estimated Cost: First year $62,972,210; Recurring years
$53,691,915.
Summary of the Collection of Information
----------------------------------------------------------------------------------------------------------------
Total
Information collection Number of Frequency of response Average time per burden
requirement responses response\1\ (hours)
----------------------------------------------------------------------------------------------------------------
Exposure Control Plan:
(c)(2)(i).................... 101,875 All Affected Employers to 24 hours per 906,980
Develop Plan. Hospital.
8 hours per
Facility for all Other
Industries
(c)(2)(vii)(B)............... 101,875 Annual Reviews and 8 hours per 238,243
Updates for All Affected Hospital.
Employers. 2 hours per
Facility for all Other
Industries
Respiratory Protection:
(f)(2)....................... 82,138 All Employers not 8 hours per 335,323
Qualified for Appendix A Hospital.
Program to Develop 4 hours per
Program. Facility for all Other
Industries
(f)(5), Appendix B........... 2,207,580 Initially, for all 30 minutes per 551,962
employees assigned employee.
respirators.
22,078 Annual refit tests for 1% 30 minutes per 5,520
of population assigned employee.
respirators.
(f)(8)....................... 82,138 Annual Evaluation of 2 hours per 83,831
Program for All Affected Hospital.
Employers not Qualified 1 hour per
for Appendix A Program. Facility for all Other
Industries
Medical Surveillance:
Medical History 1,831,724 Initially for All 1 hour per 1,831,724
(g)(3)(i)(A). Affected Employees. Hospital Employee (inc.
LHCP time).
1 hour per
Employee in all Other
Industries (inc. travel
time)
1,595,432 Annually for All Affected 1 hour per 1,595,432
Employees in Facilities Hospital Employee (inc.
not Qualified for LHCP time).
Appendix A. 1 hour per
Employee in all Other
Industries (inc. travel
time)
47,953 Initially, for New 1 hour per 47,953
Employees. Hospital Employee (inc.
LHCP time).
1 hour per
Employee in all Other
Industries (inc. travel
time)
Medical Examination 47,863 Annually, 3% of 2 hours per 72,518
(inc. History and Physical) Controlled Population at Hospital Employee in
(g)(3)(i) (B)-(D). Risk estimated to Facilities not
request exam as a result Qualified for Appendix
of having signs or A (inc. LHCP time).
symptoms of TB; have a 1\1/2\ hour per
TST conversion; or Employee in All Other
indicated as a result of Industries (inc. travel
an exposure incident. time)
Tuberculin Skin
Tests
Initial 2-Step TST 474,627 Initially, for Entire 1\1/2\ hours 1,026,377
(g)(3)(i)(A). Controlled Population at per Hospital Employee
Risk. (inc. LHCP time).
2\1/4\ hour per
Employee in All Other
Industries (inc. travel
time)
Exposure Incident 8,268 Annually, 2% of 1\1/2\ hours 17,879
(g)(3)(i)(C). Controlled Population at per Hospital Employee
Risk in Facilities (inc. LHCP time).
Qualified for Appendix A. 2\1/4\ hour per
Employee in All Other
Industries (inc. travel
time)
Pre-Exit (g)(3)(i)(E).... 76,257 Annually for Employment 1 hour for each 110,504
Turnover. Hospital Employee (inc.
LHCP time).
1\1/2\ hour per
Employee in All Other
Industries (inc. travel
time)
Prior to Initial 76,257 All New Employees with 1\1/2\ hour per 165,756
Assignment. Occupational Exposure. Hospital Employee (inc.
LHCP time).
[[Page 54167]]
Annual (g)(3)(ii)(A)..... 413,400 All employees in \1/2\ hour per 297,991
facilities not qualified Hospital Employee (inc.
for Appendix A. LHCP time).
45 minutes per
Employee in all Other
Industries (inc. travel
time)
Additional 6-month TST 131,367 All employees who: 1 hour per 171,314
(g)(3)(iii). Enter an AFB Hospital Employee (inc.
isolation room or area LHCP time).
Perform or are 1\1/2\ hour for
present during the each Employee in All
performance of high- Other Industries (inc.
hazard procedures travel time)
Transport or are
present during the
transport of an
individual with
suspected or confirmed
infectious TB in an
enclosed vehicle
Work in an
intake area in
facilities where 6 or
more confirmed TB cases
have been encountered in
the past 12 mos
Information Provided 1,965,967 Information for each 10 minutes per 327,661
to Licenced Health Care affected establishment employee.
Professional (LHCP) to provide a copy of the
(g)(6)(I). rule, and for
information on each
employee with a
respirator.
558,549 Information for each new 10 minutes per 93,091
employee assigned a employee.
respirator.
64,692 Information surrounding 10 minutes per 10,782
exposure incidents (2% employee.
of controlled population
at risk).
LHCP Written Opinion 2,745,188 Initially, for each 5 minutes per 228,766
(g)(7). medical procedure written opinion.
performed.
2,034,269 Annually, for each 5 minutes per 169,522
medical procedure written opinion.
performed.
Training:
(h)(3)(ii)(B)................ 202,066 Number of training 2 hours for 237,829
sessions in first year. employees required to
wear respirators.
1 hour for
employees with
occupational exposure
who are not assigned
respirators
Assumes 20
employees per session
(h)(3)(ii)(A)................ 106,258 Number of training For new 50,193
sessions for new employees:.
employees entering 2 hours for employees
affected occupations for required to wear
the first time + number respirators
of training sessions for 1 hour for employees
employees staying in with occupational
affected occupations, exposure who are not
but starting new jobs. assigned respirators
\1/2\ hours for
employees required to
wear respirators
15 minutes for employees
with occupational
exposure who are not
assigned respirators
(h)(3)(ii)(C)................ 154,966 Recurring number of For 25% of 57,313
training sessions. exposed employees
unable to demonstrate
competence:.
1 hour for employees
required to wear
respirators
\1/2\ hour for employees
with occupational
exposure who are not
assigned respirators
For 75% of
exposed employees able
to demonstrate
competence
Assumes 20
employees per session
Recordkeeping:
Medical (I)(1)(I)............ 3,713,645 Initially, to create a 10 minutes to 631,320
medical record for each set up each record.
affected employee.
1,358,800 Create medical records 10 minutes to 230,996
for each new employee set up each record.
with occupational
exposure.
2,447,669 Annually, for each 5 minutes to 195,814
medical procedure update each record.
performed.
[[Page 54168]]
Training (I)(3)(I)........... 264,451 Initially, to create 10 minutes to 44,957
records for each create each training
training session. record.
217,351 Annually, to reflect 10 minutes to 36,950
recurring training create each training
sessions and initial record.
training for new
employees.
Engineering controls 24,761 Annually, for each 5 minutes per 3,962
(I)(4)(I). engineering control. record.
Availability (I)(5).......... 2,037 Annually, for 2% of 5 minutes per 163
affected employers. employer.
Transfer to NIOSH............ 1 Annually, for estimated 1 1 hour per 1
employer per year to employer.
transfer records.
------------- ------------
Totals...................
First-Year.. ........... ......................... ........................ 7,098,011
Recurring... ........... ......................... ........................ 3,655,728
----------------------------------------------------------------------------------------------------------------
\1\ Estimates represent average burden hours per response. The actual burden hours per response will vary
depending on factors such as the size of the facility, current practices at the facility, and whether the
facility transfers or admits individuals with suspected or confirmed infectious TB.
Note: Estimates take into account baseline compliance with the proposed requirements.
The Agency has submitted a copy of the information collection
request to OMB for its review and approval. Interested parties are
requested to send comments regarding this information collection to the
Office of Information and Regulatory Affairs, Attn. OSHA Desk Officer,
OMB New Executive Office Building, 725 17th Street NW, Room 10235,
Washington DC 20503.
Comments submitted in response to this notice will be summarized
and/or included in the request for Office of Management and Budget
approval of the final information collection request: they will also
become a matter of public record.
Copies of the referenced information collection request are
available for inspection and copying in the OSHA Docket Office and will
be mailed immediately to any person who request copies by telephoning
Todd Owen at (202) 219-7075. For electronic copies of the Tuberculosis
information collection request, contact the Labor News Bulletin Board
(202) 219-4784, or OSHA web page on the Internet at http://
www.osha.gov/. Copies of the information collection requests are also
available at the OMB docket office.
C. Federalism
This standard has been reviewed in accordance with Executive Order
12612, 52 FR 41685 (October 30, 1987), regarding Federalism. This Order
requires that agencies, to the extent possible, refrain from limiting
State policy options, consult with States prior to taking any actions
that would restrict State policy options, and take such actions only
when there is clear constitutional authority and the presence of a
problem of national scope. The Order provides for preemption of State
law only if there is a clear Congressional intent for the Agency to do
so. Any such preemption is to be limited to the extent possible.
Throughout the development of this proposed standard, OSHA has
sought and received assistance from state representatives.
Representatives of state departments of health and labor and industries
have helped direct OSHA to pertinent information and studies on TB and
have submitted drafts of state standards relevant to TB. In addition,
representatives of state occupational safety and health departments
participated in the review of the draft standard by OSHA field offices
and in OSHA's TB Stakeholder meetings, where the requirements of the
proposed standard were presented and information was collected from
employers, employees, and their representatives on what was being done
to prevent occupational exposure to TB in the various worksites and how
an OSHA standard for TB could further reduce the exposures.
Section 18 of the Occupational Safety and Health Act (OSH Act),
expresses Congress' clear intent to preempt State laws with respect to
which Federal OSHA has promulgated occupational safety or health
standards. Under the OSH Act a State can avoid preemption only if it
submits, and obtains Federal approval of, a plan for the development of
such standards and their enforcement. Occupational safety and health
standards developed by such State-Plan states must, among other things,
be at least as effective in providing safe and healthful employment and
places of employment as the Federal standards.
The proposed tuberculosis standard is drafted so that employees in
every State will be protected by general, performance-oriented
standards. To the extent that there are State or regional
peculiarities, States with occupational safety and health plans
approved under Section 18 of the OSH Act would be able to develop their
own State standards to deal with any special problems. Moreover, the
performance nature of this standard, of and by itself, allows for
flexibility by States and employers to provide as much safety as
possible using varying methods consonant with conditions in each State.
There is a clear national problem related to occupational safety
and health for employees exposed to M. tuberculosis. Approximately 6.5%
of the U.S. adult population is infected (i.e., carrying the
tuberculosis bacillus, not manifesting active disease), and although
the prevalence of TB infection and disease varies throughout the
country, TB disease has been reported in every state. Political and
geographic boundaries do not contain infection and disease spread. The
U.S. population is mobile, moving freely from place to place for
business and pleasure. Immigrants, a group whose members are known to
have a high prevalence of TB, settle throughout the country. While
there are counties that do not report cases in a given year, the
counties change from year to year along with the number of cases
reported. In addition, reports do not always reflect all the locations
where exposure incidents can occur; infectious TB cases are often
transferred from their site of diagnosis to a distant location for
treatment and reported as a TB case only in the county
[[Page 54169]]
where treatment is administered. Finally, underreporting may occur
because some individuals with infectious TB, in particular the homeless
and clients of drug abuse facilities, do not avail themselves of
further diagnosis and treatment. TB infection and disease is truly
national in scope.
Those States which have elected to participate under Section 18 of
the OSH Act would not be preempted by this regulation and would be able
to deal with special, local conditions within the framework provided by
this performance-oriented standard while ensuring that their standards
are at least as effective as the Federal standard.
D. State Plans
The 23 States and 2 territories with their own OSHA-approved
occupational safety and health plans must adopt a comparable standard
within 6 months after the publication of a final standard for
occupational exposure to tuberculosis or amend their existing standard
if it is not ``at least as effective'' as the final Federal standard.
OSHA anticipates that this standard will have a substantial impact on
state and local employees. The states and territories with occupational
safety and health state plans are: Alaska, Arizona, California,
Connecticut, Hawaii, Indiana, Iowa, Kentucky, Maryland, Michigan,
Minnesota, Nevada, New Mexico, New York, North Carolina, Oregon, Puerto
Rico, South Carolina, Tennessee, Utah, Vermont, Virginia, the Virgin
Islands, Washington, and Wyoming. (In Connecticut and New York, the
plan covers only State and local government employees). Until such time
as a State standard is promulgated, Federal OSHA will provide interim
enforcement assistance, as appropriate.
II. Pertinent Legal Authority
The purpose of the Occupational Safety and Health Act, 29 U.S.C.
651 et seq. (``the Act'') is ``to assure so far as possible every
working man and woman in the nation safe and healthful working
conditions and to preserve our human resources.'' 29 U.S.C.
Sec. 651(b). To achieve this goal Congress authorized the Secretary of
Labor to promulgate and enforce occupational safety and health
standards. 29 U.S.C. Secs. 655(a) (authorizing summary adoption of
existing consensus and federal standards within two years of Act's
enactment), 655(b) (authorizing promulgation of standards pursuant to
notice and comment), 654(b) (requiring employers to comply with OSHA
standards).
A safety or health standard is a standard ``which requires
conditions, or the adoption or use of one or more practices, means,
methods, operations, or processes, reasonably necessary or appropriate
to provide safe or healthful employment or places of employment.'' 29
U.S.C. Sec. 652(8).
A standard is reasonably necessary or appropriate within the
meaning of Section 652(8) if it substantially reduces or eliminates
significant risk, and is economically feasible, technologically
feasible, cost effective, consistent with prior Agency action or
supported by a reasoned justification for departing from prior Agency
actions, supported by substantial evidence, and is better able to
effectuate the Act's purposes than any national consensus standard it
supersedes. See 58 Fed. Reg. 16612--16616 (March 30, 1993).
OSHA has generally considered, at a minimum, a fatality risk of 1/
1000 over a 45-year working lifetime to be a significant health risk.
See the Benzene standard, Industrial Union Dep't v. American Petroleum
Institute, 448 U.S. 607, 646 (1980); the Asbestos standard,
International Union, UAW v. Pendergrass, 878 F.2d 389, 393 (D.C. Cir.
1989).
A standard is technologically feasible if the protective measures
it requires already exist, can be brought into existence with available
technology, or can be created with technology that can reasonably be
expected to be developed. American Textile Mfrs. Institute v. OSHA, 452
U.S. 490, 513 (1981) (``ATMI''), American Iron and Steel Institute v.
OSHA, 939 F.2d 975, 980 (D.C. Cir. 1991)(``AISI'').
A standard is economically feasible if industry can absorb or pass
on the costs of compliance without threatening its long-term
profitability or competitive structure. See ATMI, 452 U.S. at 530 n.
55; AISI, 939 F.2d at 980.
A standard is cost effective if the protective measures it requires
are the least costly of the available alternatives that achieve the
same level of protection. ATMI, 453 U.S. at 514 n. 32; International
Union, UAW v. OSHA, 37 F.3d 665, 668 (D.C. Cir. 1994) (``LOTO III'').
All standards must be highly protective. See 58 FR 16614--16615;
LOTO III, 37 F.3d at 669. However, health standards must also meet the
``feasibility mandate'' of Section 6(b)(7) of the Act, 29 U.S.C.
Sec. 655(b)(5). Section 6(b)(5) requires OSHA to select ``the most
protective standard consistent with feasibility'' that is needed to
reduce significant risk when regulating health hazards. ATMI, 452 U.S.
at 509.
Section 6(b)(5) also directs OSHA to base health standards on ``the
best available evidence,'' including research, demonstrations, and
experiments. 29 U.S.C. Sec. 655(b)(5). OSHA shall consider ``in
addition to the attainment of the highest degree of health and safety
protection * * * the latest scientific data * * * feasibility and
experience gained under this and other health and safety laws.'' Id.
Section 6(b)(7) authorizes OSHA to include among a standard's
requirements labeling, monitoring, medical testing and other
information gathering and transmittal provisions. 29 U.S.C.
Sec. 655(b)(7).
Finally, whenever practical, standards shall ``be expressed in
terms of objective criteria and of the performance desired.'' Id.
III. Events Leading to the Proposed Standard
Tuberculosis (TB) is a contagious disease caused by the bacterium
Mycobacterium tuberculosis (M. tuberculosis). Infection is usually
acquired by the inhalation of airborne particles carrying the
bacterium. These airborne particles, called droplet nuclei, can be
generated when persons with infectious pulmonary or laryngeal TB cough,
sneeze, or speak. TB has long been considered an occupational hazard in
the health care setting. However, it is inhalation exposure to
aerosolized M. tuberculosis and not some other factor unique to the
health care setting that places workers at risk of infection. Thus, any
work setting where employees can reasonably be anticipated to encounter
individuals with infectious TB also contains the occupational hazard of
TB infection.
On December 21, 1992, the Labor Coalition to Fight TB in the
Workplace (the Coalition) requested the Agency to issue nationwide
enforcement guidelines to protect workers against exposure to TB in
health care, criminal justice, and other high risk settings and to
issue a Joint Advisory Notice on TB in conjunction with the Centers for
Disease Control and Prevention (CDC) (Ex. 2). This petition was signed
by the presidents of the Service Employees International Union (SEIU),
the American Federation of State, County, and Municipal Employees
(AFSCME), and the American Federation of Teachers (AFT), and was
endorsed by 9 other unions. The petition included a list of provisions
that the petitioners felt should be included in the guidelines, ranging
from a written control plan and medical surveillance to anti-
discrimination language and medical removal protection.
[[Page 54170]]
Eight months later, on August 25, 1993, the Coalition petitioned
OSHA to initiate rulemaking for a permanent standard issued under
Sec. 655(b) of the Act to protect workers from occupational
transmission of TB (Ex. 1). Citing the recent resurgence of TB and the
emergence and increasing rate of new cases of multidrug-resistant TB
(MDR-TB), the petitioners stressed the need for a substance-specific
standard to address the hazards associated with occupational exposures
to TB. The petitioners contended that the non-mandatory CDC TB
Guidelines do not provide adequate protection because they are not
fully or rigorously implemented in most workplaces. They also stated
that in every outbreak of TB investigated by CDC, noncompliance with
the Guidelines was evident.
In addition to a permanent standard, the petitioners also requested
that OSHA immediately issue the nationwide enforcement guidelines that
the Coalition had previously requested, and that OSHA promulgate an
Emergency Temporary Standard (ETS) as an interim measure. The Coalition
requested that the standard be applicable to all work settings where
employees can reasonably anticipate contact with infectious TB. The
petition included a discussion on occupational risk that included both
the traditional high-risk occupations and other occupations such as
sheet metal workers, postal workers, airline employees, teachers, and
office workers.
Like the request for nationwide enforcement guidelines, the
petition contained provisions that the petitioners requested be
included in the standard. Examples include a facility hazard assessment
and written exposure control plan, engineering and work practice
controls, respiratory protection, medical surveillance (e.g.,
tuberculin skin testing) and counseling, post-exposure management,
outbreak management, training, and recordkeeping.
On October 8, 1993, OSHA issued nationwide enforcement procedures
for occupational exposure to TB. The compliance document contained the
enforcement procedures that the Agency could and would use in certain
work settings for protecting workers with occupational exposure to TB.
In the compliance procedures, the Agency noted that although OSHA has
no standard designed specifically to reduce occupational exposure to
TB, the Agency has existing standards that apply to this hazard. For
example, 29 CFR 1910.134 requires employers to provide respiratory
protection equipment and 29 CFR 1910.145(f) requires accident
prevention tags to warn of biological hazards. In addition, section
5(a)(1), the General Duty Clause of the Act, requires that each
employer:
* * * furnish to each of his employees employment and a place
of employment which are free from recognized hazards that are
causing or are likely to cause death or serious physical harm to his
employees.
On January 26, 1994, in response to their August 25 petition,
Secretary of Labor Robert B. Reich informed the petitioners that OSHA
was initiating rulemaking on a permanent standard to be issued under
Section 6(b)(5) of the Act for occupational exposure to TB (Ex. 1B). At
the same time, the petitioner's request for an ETS was denied. The
Agency had determined that the available data did not meet the criteria
for an ETS as set forth in Section 6(c) of the Act. However, OSHA
committed to enforcing existing regulations and Section 5(a)(1) of the
Act in certain work settings while preparing this standard.
On October 28, 1994 the CDC issued revised guidelines for
preventing the transmission of tuberculosis in health care facilities
(Ex. 4B). In addition, in June of 1995, the National Institute for
Occupational Safety and Health (NIOSH) published revised certification
procedures for non-powered air purifying particulate respirators (Ex.
7-261). As a result of changes in these two documents, OSHA issued
revised enforcement policies and procedures relative to TB in February
of 1996 (Ex. 7-260).
In October and November of 1995, OSHA held a series of meetings
with stakeholder groups representing labor unions, professional
organizations, trade associations, state and federal government,
representatives of employers, as well as frontline workers from the
various sectors anticipated to be covered by the proposed standard.
During these meetings, participants provided input relative to the
concepts and approaches OSHA was considering for the proposed
tuberculosis standard.
In September of 1996, in accordance with the Small Business
Regulatory Enforcement Fairness Act of 1996 (SBREFA), a Small Business
Advocacy Review Panel was convened to consider the impact of OSHA's
draft proposed tuberculosis standard on affected small entities. The
panel, comprised of members from the Office of Advocacy of the Small
Business Administration (SBA), the Office of Management and Budget
(OMB), and OSHA, prepared a report based on the Panel's findings and
recommendations with regard to comments on the standard received from
small business employers. This report was submitted to the Assistant
Secretary for OSHA for its consideration during the development of the
standard (Ex. 12). OSHA's proposed standard reflects input generated
during both the stakeholder meetings and the SBREFA review process.
Comparison of OSHA's Proposed Standard and CDC's Revised Guidelines
In preparing its proposed standard for TB, OSHA has relied heavily
on the expertise of CDC. The Agency has consulted with CDC and has
incorporated the basic elements of CDC's revised guidelines for
preventing the transmission of M. tuberculosis in health care
facilities in this proposed standard. Both CDC and OSHA rely on
minimizing exposures and consequent transmission by identifying
suspected infectious TB individuals and isolating them. The OSHA
proposed standard includes the following CDC components: written
exposure control plans, procedures for early identification of
individuals with suspected or confirmed infectious TB, procedures for
initiating isolation of individuals with suspected or confirmed
infectious TB or for referring those individuals to facilities with
appropriate isolation capabilities, procedures for investigating
employee skin test conversions, and education and training for
employees. In addition, OSHA has incorporated CDC recommendations for
engineering control measures such as the use of negative pressure for
AFB isolation rooms or areas, daily monitoring of negative pressure
while AFB isolation rooms are in use for TB, HEPA filtration of
recirculated air from AFB isolation rooms, and periodic maintenance and
monitoring of engineering controls. With regard to respiratory
protection, OSHA has adopted CDC's standard performance criteria for
the selection of respiratory protection devices appropriate for use
against M. tuberculosis. And finally, where appropriate, OSHA has
attempted to assure that where certain practices are required by OSHA's
proposed standard, e.g., tuberculin skin testing and medical management
and follow-up of employees who acquire TB infections or active disease,
these practices are conducted according to the current recommendations
of the CDC. Therefore, OSHA's proposed standard for occupational
exposure to TB closely follows CDC's recommended elements for a TB
infection control program.
However, there are some minor differences between OSHA's proposed
standard and CDC's guidelines that go
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beyond the obvious enforcement distinction between a guideline and a
standard. These differences are found primarily in the areas of risk
assessment, medical surveillance and respiratory protection. Even so,
OSHA believes that despite these differences the vast majority of the
provisions included in this proposed standard closely track the
recommendations of the CDC. The following discussion identifies where
these differences occur and describes the extent of these differences
and the degree to which they impact on employers' responsibilities
under the proposed standard.
Risk Assessment
As a part of its guidelines, CDC recommends that a risk assessment
be conducted in all facilities to assess the risk of transmission of M.
tuberculosis in each facility. This risk assessment is to be conducted
using information such as the profile of TB in the community, the
number of suspected and confirmed cases of TB among patients and health
care workers, results of health care worker tuberculin skin testing
(i.e., conversion rates), and observation of TB infection control
practices. Using the results of this risk assessment, appropriate
infection control interventions can then be selected based on the
actual risk in the facility. CDC includes a protocol for conducting
this risk assessment in which there are 5 categories of risk:
``minimal'', ``very-low'', ``low'', ``intermediate'', and ``high''.
Each category from ``minimal'' to ``high'' has an increasing number of
infection control interventions that are recommended for each
particular level of risk.
OSHA, however, has chosen a simpler approach and is not requiring
employers to conduct such a risk assessment. Consistent with other
standards, OSHA has determined that employees in the work settings and
employees providing services set forth in the scope section are at risk
of occupational exposure to TB. Their employers are required to conduct
an exposure assessment to determine which employees have occupational
exposure, i.e., reasonably anticipated contact with an individual with
suspected or confirmed infectious TB or air that may contain
aerosolized M. tuberculosis. The standard then specifies the provisions
applicable for the employees whom the employer has identified as having
occupational exposure. In addition, consistent with its approach in
other standards, OSHA does not require that individual risk assessments
be conducted by each work setting covered under the standard, as they
may be too difficult and burdensome for employers to prepare. Also,
many work settings will have too few occupationally exposed employees
to do an accurate risk assessment. Finally, conducting the risk
assessments in order to determine applicable duties may require a level
of expertise some facilities lack, making enforcement burdensome for
the Agency.
OSHA realizes, however, that in many work settings, very few
individuals with suspected or confirmed infectious TB may be seen and
that in many of those work settings, individuals with suspected or
confirmed infectious TB will be transferred to other facilities that
are better equipped to provide services and care using appropriate TB
isolation precautions. Because there is likely to be less risk of
transmission of M. tuberculosis in those situations, OSHA believes that
it is possible to make the standard less burdensome for the employers
with these types of work settings while still maintaining worker
protection.
For example, an employer who can demonstrate that his or her
facility or work setting: (1) Does not admit or provide medical
services to individuals stwith suspected or confirmed infectious TB,
(2) has not had any individuals with confirmed infectious TB within the
work setting within the last 12 months, and (3) is located in a county
that, in the past 2 years, has had 0 cases of confirmed infectious TB
reported in one year and fewer than 6 cases of confirmed infectious TB
reported in the other year, does not have to comply with all provisions
of the standard. Such employers would only be responsible for
compliance with certain provisions, e.g., a written exposure control
plan, a baseline skin test and medical history, medical management and
follow-up after exposure incidents, medical removal protection where
necessary, employee training, and recordkeeping. These provisions are
very similar to the recommendations of the CDC for facilities
classified as having ``minimal risk,'' i.e., no TB in the community or
in the facility. The only major difference is that CDC does not
recommend baseline skin testing. However, CDC does state that baseline
skin testing would be advisable so that if an unexpected exposure does
occur, conversion could be distinguished from positive skin test
results caused by previous exposures.
Medical Surveillance
In the area of medical surveillance, the main differences between
OSHA and CDC are related to tuberculin skin testing. OSHA requires
baseline skin testing for all employees whom the employer identifies as
having occupational exposure. CDC recommends baseline skin testing for
all employees with potential exposure except those who work in
facilities that fall into CDC's ``minimal risk'' category. However, CDC
notes that even for employees in ``minimal risk'' facilities, it may be
advisable to perform baseline skin testing so that if unexpected
exposures do occur, conversions can be distinguished from positive skin
test results caused by previous exposures. Thus, there is little
difference between OSHA requirements and CDC recommendations with
regard to baseline skin testing.
Relative to periodic skin testing, OSHA requires periodic re-
testing for all employees identified as having occupational exposure
who have negative skin tests except for the employees of those
employers who have no TB in the community and who have not encountered
any individuals with confirmed infectious TB in their work settings
within the past year. CDC recommends re-testing for employees in the
``low'', ``intermediate'', and ``high'' risk categories. According to
the CDC guidelines, periodic re-testing is not necessary for employees
in the ``minimal'' risk category or the ``very-low'' risk categories.
CDC's periodic skin test recommendations for the ``minimal'' risk
category are similar to OSHA's limited program for employers who do not
admit or provide medical services to individuals with suspected or
confirmed infectious TB, have not encountered any confirmed infectious
TB in their work setting, and are located in a county that, in the past
2 years, has reported 0 cases of confirmed infectious TB in one year
and fewer than 6 cases in the other year. OSHA is different from the
CDC in that employees in a ``very-low risk category'' are required to
be periodically retested. However, CDC notes that even in the ``very-
low'' risk category, employees who are involved in the initial
assessment of individuals in emergency departments and admitting areas
may have potential exposure and thus may need periodic re-testing.
Another difference between CDC and OSHA is the frequency of the re-
testing. This is primarily due to the fact that OSHA's required
frequencies are based on the type of work that employees do that result
in exposures whereas CDC's recommendations are based more on evidence
of conversions. For example, OSHA requires re-testing every six months
for all employees who (1) enter AFB isolation rooms or areas, (2)
perform high-hazard procedures, (3)
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transport individuals with suspected or confirmed infectious TB in an
enclosed vehicle, or (4) work in intake areas where early
identification procedures are performed (e.g., emergency departments,
admitting areas) in facilities where 6 or more individuals with
confirmed infectious TB have been encountered in the past 12 months.
For all other employees with occupational exposure, re-testing is
required every 12 months. In comparison, CDC recommends re-testing
every year for employees in ``low'' risk categories, every 6-12 months
for employees in ``intermediate'' risk categories, and every 3 months
for employees in ``high'' risk categories. Under CDC recommendations,
employees in ``low'' risk categories who enter AFB isolation rooms or
areas or employees who transport individuals with suspected or
confirmed infectious TB in an enclosed vehicle would be re-tested every
12 months. However, under OSHA requirements, those same employees would
be required to be re-tested every six months. Thus, OSHA is more
protective than CDC in this case.
OSHA also would require that employees who perform high-hazard
procedures or who work in intake areas where early identification
procedures are performed in facilities that encounter 6 or more
individuals with confirmed infectious TB be re-tested every six months.
Under CDC's Guidelines employees in areas in which cough-inducing
procedures are performed on individuals who may have active TB are
recommended to follow an intermediate risk protocol. Similarly, CDC
recommends that an intermediate risk protocol be followed in areas
where more than six individuals who may have active TB receive initial
assessment and diagnostic evaluation (e.g., ambulatory care, emergency
departments, admitting areas). CDC recommends re-testing every 6-12
months for employees in intermediate risk categories. OSHA would
require re-testing every 6 months for the two situations above, which
is very similar to CDC's recommendation of re-testing every 6-12
months.
CDC is more protective in its recommendations for employees in the
``high'' risk category. These employees are recommended to be re-tested
every 3 months. OSHA does not have a requirement for re-testing
employees every 3 months. However, after an exposure incident, OSHA
requires that a skin test be administered as soon as feasible and again
3 months after the exposure incident, if the first skin test is
negative. Since it is possible that an exposure incident(s) could be
the type of event that would cause an employee(s) to be included in the
``high'' risk category as defined by CDC, OSHA requirements, to some
extent, track the CDC recommendations for a higher frequency of
periodic skin testing.
With regard to two-step testing, both OSHA and CDC require or
recommend two-step testing at the time baseline skin testing is
administered. Also, both OSHA and CDC add that two-step testing is not
necessary if the employee has had a documented negative skin test
within the last 12 months. CDC is different from OSHA in that its
Guidelines imply that two-step testing can be discontinued if there is
evidence of a low frequency of boosting in the facility. OSHA's
proposed standard does not allow such an exemption, i.e., for each
employee who must have a baseline skin test at the time of the initial
medical examination, the skin test must include a two-step test unless
the employee has a documented negative test within the last 12 months,
regardless of the frequency of boosting in the facility. The value of
two-step skin testing is that it enables one to distinguish true
conversions from boosted reactions. OSHA believes that this is
important to know for each employee because if the employee is
incorrectly identified as having converted, he or she may needlessly be
subjected to preventive therapy that may have toxic side effects of its
own. Since it is important to know the true skin test status for each
employee, OSHA has preliminarily concluded that it is inappropriate to
allow the overall frequency of boosting among employees in a facility
to dictate whether any one employee receives two-step testing at the
time of his or her baseline testing.
Respiratory Protection
OSHA requirements and CDC recommendations for respiratory
protection are very similar. A respirator is a personal protective
equipment device worn over the nose and mouth of the employee that
filters certain airborne contaminants from the inhaled air. OSHA has
adopted CDC's performance criteria for respirators appropriate for use
for TB. Also, both OSHA and CDC have similar requirements or
recommendations that respirators be worn when entering an isolation
room, when performing cough-inducing procedures or aerosol-generating
procedures on an individual with suspected or confirmed infectious TB,
when repairing or maintaining air systems that may contain aerosolized
M. tuberculosis, when transporting an individual with suspected or
confirmed infectious TB in an enclosed vehicle and when working in a
residence where an individual with suspected or confirmed infectious TB
is known to be present. However, OSHA also requires that respirators be
worn when employees are transporting individuals with suspected or
confirmed infectious TB within the facility if those individuals are
not masked (e.g., a surgical mask or a valveless respirator). CDC does
not have a similar recommendation for respiratory protection while
transporting individuals within the facility, but CDC does recommend,
and assumes to some extent, that individuals with suspected or
confirmed infectious TB are masked whenever they are outside an
isolation room. In addition, OSHA requires that respirators be worn
when employees work in an area where an unmasked individual with
suspected or confirmed infectious TB has been segregated or otherwise
confined. For example, this provision would cover employees such as
those who work in admitting areas and must attend to unmasked
individuals with suspected or confirmed infectious TB while those
individuals are awaiting transfer. These types of employees are likely
to be found in facilities that would meet CDC's definition of
``minimal'' risk. CDC states that respiratory protection is not
necessary for employees in the ``minimal'' risk category. However,
again, CDC recommends that if an individual with suspected or confirmed
infectious TB is identified in a ``minimal'' risk facility, the
individual should be masked while he or she is awaiting transfer to
another facility, thus obviating the need for respiratory protection.
OSHA, on the other hand, cannot require employers to mask clients or
patients in a facility, and the Agency must therefore include
provisions for respirator use to protect potentially exposed employees.
However, consistent with CDC, OSHA proposes not to require respirators
where the employer elects, as a part of his or her own administrative
policies, to mask individuals with suspected or confirmed infectious
TB. Thus, when individuals with suspected or confirmed infectious TB
are masked while they are awaiting transfer to another facility or
while they are being transported within the facility, employees would
not be required by the standard to wear a respirator.
In some instances, the CDC may be more protective than OSHA with
regard to respiratory protection. The CDC states that the facility's
risk assessment may identify selected settings where the
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estimated risk of transmission of M. tuberculosis may be such that a
level of respiratory protection exceeding the standard performance
criteria is appropriate (e.g., more protective negative pressure
respirators, powered air purifying respirators). The examples given of
such selected settings are a bronchoscopy performed on an individual
suspected of having TB and an autopsy performed on a deceased person
suspected of having had active TB at the time of death. OSHA does not
have a similar requirement for more protective respiratory protection.
Respirators meeting the minimal performance criteria laid out by the
standard would be required by OSHA for employees performing all high-
hazard procedures, including bronchoscopies and aerosol-generating
autopsy procedures.
IV. Health Effects
Introduction
For centuries Tuberculosis (TB) has been responsible for the death
of millions of people throughout the world. It was not until 1882,
however, that Robert Koch identified a species of bacteria,
Mycobacterium tuberculosis (M. tuberculosis), as the cause of TB.
TB is a communicable disease that usually affects the lungs. The
airborne route is the predominant mode of transmission, a situation
created when individuals with infectious TB discharge the bacilli from
the lungs when coughing, sneezing, speaking or singing. Some
individuals who breathe contaminated air become infected with TB. Most
often, the immune system responds to fight the infection. Within a few
weeks, the infected lesions become inactive and there is no residual
change except for possible lymph node calcifications. These individuals
will have a positive skin test result. They will harbor the infection
for life. At some time in the future, the infection can progress and
can become an active disease, with pulmonary infiltration, cavitation,
and fibrosis, possibly causing permanent lung damage and even death.
With some exceptions, however, TB is treatable with antimicrobial
drugs. If the active TB is treated early, there will be minimal
residual lung damage. For this reason, individuals who have a TB
exposure incident and develop a TB infection are treated to prevent
progression to active TB disease.
With the introduction of antimicrobial drug treatment in the 1940s
and the creation of programs in the United States such as the U.S.
Public Health Service's Tuberculosis Program, there began a decline in
the incidence of active TB cases in the U.S. From 1953, when active
cases began to be reported in the U.S., until 1984, the number of
annual reported cases declined 74%, from 84,304 (53 per 100,000) to
22,255 (9.4 per 100,000) (Ex. 7-50). However, this steady decline in TB
cases did not continue. Instead, from 1985 through 1992, the number of
reported TB cases increased 20.1% from 22,201 to 26,673 (10.5 cases per
100,000) (Ex. 6-13).
This resurgence in TB brought to attention a number of problems in
the existing TB control programs. The direction of resources to areas
with the highest increase in active cases has caused this increase to
decline. The number of cases reported for 1995 indicates that the rate
of active TB has returned to its 1985 levels. In 1995, a total of
22,813 cases of TB (8.7 per 100,000) was reported to CDC (Ex. 6-34).
While this represents a decline in active TB, the 1995 rate is still
two and one half times greater than the target case rate of 3.5 per
100,000 for the year 2000 and approximately 87 times the goal of less
than one case per million population by the year 2010 proposed by the
Advisory Committee on the Elimination of Tuberculosis (Ex. 6-19).
TB continues to be a national problem. Each year, cases of active
disease are reported in every state in the Nation and in a substantial
majority of counties nationwide. CDC estimated in 1990 that
approximately 10 million people were infected with the tuberculosis
bacterium and that approximately 90% of the new cases of active disease
that arise in the United States come from this already infected group
(Ex. 7-52). Given the recent resurgence of TB, it is likely that a new
population of individuals has been infected as well. Of great concern
are strains of M. tuberculosis that have emerged that are resistant to
several of the first-line anti-TB drugs normally used to treat TB
infection and disease (e.g., isoniazid and rifampin). This drug-
resistant form of the disease, referred to as multidrug-resistant TB or
MDR-TB, is more often a fatal form of TB due to the difficulty in
finding antimicrobial drugs to stop the bacteria's growth and
progressive tissue destruction. In addition, individuals with MDR-TB
often remain infectious for longer periods of time due to delays in
diagnosing resistance patterns and initiating appropriate treatment.
This, in turn, increases the risk that infectious individuals will
transmit the organism to other persons coming in contact with them.
Most of the decreases in reported cases of TB since 1992 have
occurred in areas such as New York City, where resources have been
invested to improve or initiate TB control provisions, such as those
outlined in OSHA's proposed standard. However, the 1995 statistics show
that over the course of four years there is substantial variability in
the increases and decreases of cases reported by each state for any
given year (Ex. 6-34). In 1995, 15 states reported an increase in the
number of TB cases compared with 1994. In addition, a recent study has
shown that MDR-TB has spread to patients in Florida and Nevada, and to
health care workers in Atlanta, Georgia and Miami, Florida. Moreover,
one individual with MDR-TB infected or caused disease in at least 12
people in a nursing home in Denver, Colorado (Ex. 7-259). This study
shows very clearly the ability of TB to be spread to different areas of
the country. This is to be expected given the mobile nature of today's
society and the frequency with which people travel. Immigration also
contributes to the incidence of the disease. For example, while the
number of active TB cases has decreased among U.S. born persons, the
number of foreign born persons reported with TB has increased 63% since
1986, with a 5.4% increase in 1995 (i.e., from 7,627 cases in 1994 to
8,042 cases in 1995). Thirty to fifty percent of these cases were
diagnosed 1 to 5 years after the individual enters the U.S. (Ex. 6-34).
Thus, tuberculosis continues to be a public health problem throughout
the United States.
The following discussion will briefly describe the basic concepts
and terminology associated with TB as well as common factors that
facilitate its transmission from one individual to another. This
discussion will also include a review of studies relating to the
occupational transmission of TB.
Background
TB is a contagious disease caused by the bacterium M. tuberculosis.
Infection is generally acquired by the inhalation of airborne particles
carrying the bacterium. These airborne particles, called droplet
nuclei, can be generated when persons with pulmonary or laryngeal
tuberculosis in the infectious state of the disease cough, sneeze,
speak or sing.
In some individuals exposed to droplet nuclei, tuberculosis bacilli
enter the lung and establish an infection (Ex. 7-52). Once in the
alveoli, the tuberculosis bacilli are taken up by alveolar macrophages
and spread throughout the body by the lymphatic system, until the
immune response limits further growth (usually a period of two to ten
weeks). In most cases the tuberculosis bacilli are contained by the
[[Page 54174]]
immune response. Macrophage cells engulf the bacteria, which limits the
spread of the bacilli. Initial lesions from infection heal; however,
small calcifications called tubercles are formed and may remain a
potential site of later reactivation.
Individuals in this state are infected with TB. They will show a
positive skin test and they are at risk of developing active TB, a risk
they carry throughout their lifetime. In many cases, as described
below, preventive therapy is initiated with anti-TB drugs to prevent
the progression to active TB disease. These drugs are toxic and may
cause adverse effects such as hepatitis. Severe preventive therapy-
associated hepatitis cases have necessitated liver transplants and in
some cases have resulted in death (Ex. 6-10).
When the bacilli are not contained by the immune system, they
continue to grow and invade the tissue, leading to the progressive
destruction of the organ involved, which in most cases is the lung,
i.e., pulmonary tuberculosis. The inflammatory response caused by the
disease produces weakness, fever, chest pain, cough, and, when blood
vessels are eroded, bloody sputum. Also, many individuals have
drenching night sweats over the upper half of the body several times a
week (Ex. 5-80). The extent of disease varies from minimal symptoms of
disease to massive involvement with extensive cavitation and
debilitating constitutional and respiratory symptoms. Since
tuberculosis bacilli are spread throughout the body after the initial
infection, other organs may also be infected and disease may occur at
sites outside the lung, i.e., extrapulmonary tuberculosis.
There are two general stages of TB, tuberculosis infection and
active tuberculosis disease. Individuals with tuberculosis infection
and no active disease are not infectious. These tuberculosis infections
are asymptomatic or subclinical and are only detected by a positive
response to a tuberculin skin test. However, there are some individuals
whose immune system is impaired and cannot mount a sufficient response
to skin test antigens, i.e., they are anergic. Such individuals may be
infected, although they do not show a positive response to the skin
test. Individuals with tuberculosis infection and no disease would have
negative bacteriologic studies and no clinical or radiographic evidence
of tuberculosis disease. However, these individuals are infected for
life and are at risk of developing active TB in the future.
Anti-tuberculosis drugs may be used for individuals with TB
infection but who do not have active disease. In these cases, the
antimicrobials are used as preventive therapy to prevent the onset of
active disease. Because of the toxicity associated with the
antimicrobials, preventive therapy may not be appropriate for all
infected individuals. Various factors are considered to determine
whether an infected individual is an appropriate candidate for
preventive therapy (e.g., age, immune status, how recently the
infection occurred, and other high-risk factors associated with TB)
(Ex. 7-52, pg. 17). Isoniazid is currently the only drug that has been
well tested in humans for its efficacy as preventive therapy (Ex. 7-50,
pg. 61). However, serious side effects may result from isoniazid. A
study in New York for the years 1991 to 1993 examined cases of
hepatitis induced by isoniazid preventive therapy. In this study, 10
patients undergoing preventive therapy for TB were identified at a
transplant center. Eight of these patients had developed hepatitis from
isoniazid. Five received a liver transplant; the other three died while
awaiting a liver donor. In addition, one of the transplant patients
died after transplantation. Thus, preventive therapy may carry
considerable risks for infected individuals.
In those cases where isoniazid cannot be tolerated by the patient
or where it is suspected that infection resulted from exposure to
isoniazid-resistant strains of M. tuberculosis, rifampin may be
recommended for preventive therapy. Considerations for such alternative
drug therapies are made on a case-by-case basis by the health care
provider based on the medical and case history of the infected patient.
Rifampin has adverse side effects as well. However, preventive therapy
using rifampin has not been followed as well as that involving
isoniazid and therefore, its side effects are less well characterized.
Individuals with active TB have clinical and/or radiographic
evidence of disease. The initial laboratory method for diagnosing TB is
the Acid Fast Bacilli (AFB) smear. This is a quick and easy technique
in which body fluids, typically sputum samples, from individuals with
suspected TB are examined for mycobacteria. However, this type of test
only permits a presumptive diagnosis of TB since the test cannot
distinguish between tuberculosis mycobacteria and other non-
tuberculosis mycobacteria. Chest X-rays may also be used to diagnose
active TB; however, some individuals with TB may have X-ray findings
that are atypical of those usually associated with TB (e.g., HIV
infected individuals). The diagnosis of clinically active TB is most
definitively established by the isolation of M. tuberculosis in
culture. However, it may take three to six weeks or longer from
obtaining a culture to getting a result.
Individuals with active TB disease may be infectious, especially if
they are untreated or inadequately treated and if the disease is in the
lungs. The clinical symptoms of pulmonary TB include loss of appetite,
weight loss, fatigue, fever, night sweats, malaise, cough with
productive sputum and/or blood, and chest pain. The extent of the
disease varies from very minimal symptoms to extensive debilitating
constitutional and respiratory symptoms. If untreated, the pulmonary TB
follows a chronic and progressive course in which the tissue is
progressively destroyed. It has been estimated that approximately 40 to
60% of untreated cases result in death (Exs. 5-80, 7-50, and 7-66).
However, even among cured cases of TB, long-term damage can result,
including impaired breathing due to lung damage (Ex. 7-50, pg. 31).
Approximately 90% of immunocompetent adults who are infected do not
develop active TB disease. However, for 10% of infected immunocompetent
adults, either directly after infection or after a latency period of
months, years or even decades, the initial infection progresses to
clinical illness, that is, active TB (Ex. 4B). The risk of developing
active TB is increased for individuals whose immune system is impaired
(i.e., immunocompromised). Such individuals include persons undergoing
treatment with corticosteroid or immunosuppressive drugs (e.g., persons
with organ transplants or persons undergoing chemotherapy for cancer),
persons suffering from malnutrition or chronic conditions such as
asthma and emphysema, and persons infected with the human
immunodeficiency virus (HIV).
The main first-line drugs currently used to treat active TB are
isoniazid, rifampin, pyrazinamide, ethambutol and streptomycin.
Combinations of these antimicrobials are used to attack the
tuberculosis bacilli in the body. Recommended treatment regimens
include two or more drugs to which the bacilli are susceptible, because
the use of a single drug can lead to the development of bacilli
resistant to that drug (Ex. 5-85). Treatment with these first-line
drugs involves a two-phase process: an initial bactericidal phase for
the quick elimination of the bulk of bacilli from most body sites and a
longer-term sterilizing phase for eliminating the remaining bacilli.
[[Page 54175]]
Different regimes of drug treatment (i.e., the types of drugs and
frequency of administration) are recommended depending on the medical
history of the patient involved and the results of drug susceptibility
testing. The U.S. Public Health Service has recommended options for the
initial therapy and dosage schedules for the treatment of drug-
susceptible TB (Ex. 4B). While these antimicrobials are effective in
the treatment of active TB, some of these drugs also have toxic
potential. Adverse side effects of these drugs include hepatitis,
peripheral neuropathy, optic neuritis, ototoxicity and renal toxicity
(Ex. 7-93). Thus, patients undergoing TB therapy must also be monitored
for drug toxicity that may occur from anti-tuberculosis drugs.
Individuals with active disease who are infectious may need to be
hospitalized in order to provide isolation so that they will not infect
other individuals. After the initiation of treatment for active TB,
improvement of the disease can be measured through clinical
observations such as loss of fever, reduction in coughing, increased
appetite and weight gain. A reduction in the number of bacilli in
sputum smears also indicates improvement. Three consecutive negative
sputum smears generally indicate that the individual is no longer
infectious. However, decisions about infectiousness are usually
determined on a case-by-case basis after taking a number of factors
into consideration, such as the presence of cough, the positivity of
sputum smears, and the status or response to chemotherapy. Although no
longer infectious to other individuals, the individual undergoing
treatment still has tuberculosis disease and must continue treatment.
Discontinuing or erratically adhering to the treatment regime can allow
some of the bacilli to survive such that the individual will be at risk
of becoming ill and infectious again (Ex. 7-52, p. 25).
Not all strains of the tuberculosis bacilli are susceptible to all
of the antimicrobials used to treat TB. In some instances, drug-
resistant forms of M. tuberculosis may emerge. Drug resistance may
emerge by 1 of 3 mechanisms (Exs. 5-85; 7-50, pp. 44-47). Drug-
resistant TB may occur naturally from random mutation processes, i.e.,
primary resistance. In addition, drug-resistant TB may result due to
inadequate or erratic treatment, i.e., acquired resistance. In these
cases, erratic or inadequate treatment allows the tuberculosis bacilli
to become resistant to one or several of the drugs being used. Finally,
drug-resistant TB may result due to the active transmission of drug-
resistant TB from an individual already infected with drug-resistant
strains of the tuberculosis bacteria, i.e., transmitted resistance. In
recent years, drug-resistant forms of TB have emerged that are
resistant to two or more of the first-line drugs used to treat TB, such
as isoniazid and rifampin, two of the most effective anti-TB drugs.
These drug-resistant forms of the disease are referred to as multidrug-
resistant TB or MDR-TB. MDR-TB represents a significant form of drug-
resistant TB from a public health standpoint, since its resistance to
the first-line drugs used for therapy complicates finding adequate
therapy regimens that will control the bacilli's growth.
Treatment of drug-resistant TB is determined on a case-by-case
basis, using information from the patient's medical history and drug
susceptibility testing. The recommended course of treatment will vary
depending on the drugs to which the bacilli are susceptible. Compared
to conventional TB drug therapy, MDR-TB, in general, requires more
complex interventions, longer hospitalization and more extensive
laboratory monitoring. The risk of death from such infections is
markedly increased. For example, from January 1990 through September
1992, the CDC investigated eight outbreaks of MDR-TB. In these
outbreaks, 253 patients were infected, of whom approximately 75% died
(Ex. 3-38-A). Many of these were immunocompromised due to infection
with HIV. The interval from the time of TB diagnosis to the time of
death ranged from 4 to 16 weeks, with a median time of 8 weeks.
Factors Affecting Transmission
A number of factors can influence the likelihood of acquiring a
tuberculosis infection: (1) The probability of coming into contact with
an individual with infectious TB, (2) the closeness of the contact, (3)
the duration of the contact, (4) the number of tuberculosis bacilli in
the air, and (5) the susceptibility of the uninfected individual.
Several environmental conditions can influence the likelihood of
infection. For example, the volume of shared air space, the amount of
ventilation, the presence or absence of sunlight, the humidity and the
crowded nature of the living quarters. These types of factors will
affect the probability of acquiring a tuberculosis infection after
being exposed to an individual with infectious TB. MDR-TB is not more
contagious than drug-susceptible forms of the disease. However, due to
time delays in diagnosing resistance patterns and initiating adequate
treatment, individuals with active MDR-TB may remain infectious for
longer periods of time. Consequently, the likelihood that they will
infect other noninfected individuals is increased.
Once infection occurs, other factors may influence the probability
of progressing to the active form of disease. As previously discussed,
10% of immunocompetent adults infected with TB develop active TB. Three
to five percent of untreated immunocompetent adults develop active TB
within the first year after infection (Ex. 7-50, pg. 30; 7-52). Thus,
recently infected individuals have the highest risk of developing
active TB. This risk is increased for individuals whose immune system
is impaired (e.g., persons being treated with immunosuppressive or
glucocorticoid drugs, persons with chronic conditions such as asthma or
emphysema or persons infected with the HIV). The probability of
developing active disease can also be influenced by other conditions
that may alter immune function such as overall decreased general health
status, malnutrition, and increasing age.
The resurgence of TB in the United States from 1985 to 1992 has
been attributed to a number of interacting factors: (1) The inadequate
control of disease in high prevalence areas; (2) the increase in
poverty, substance abuse, poor health status and crowded substandard
living conditions; and (3) the growing number of inmates, residents of
homeless shelters, elderly persons in long-term care facilities,
persons with HIV infection and immigrants from countries with a high
prevalence of TB infection (Ex. 7-50). This increase has begun to
decline, with the 1995 case levels approaching the 1985 levels.
However, a main reason for this decrease is the implementation of TB
control measures, like those proposed in this standard, in selected
areas of the country such as New York City. OSHA believes that
implementation of such measures is necessary to prevent a resurgent
peak such as that observed from 1985 to 1992 and to realize the goal
set out by the National Advisory Committee for the Elimination of
Tuberculosis. The following discussion describes some of the health
effects data related to occupational exposure to TB and illustrates how
the presence of TB control measures influences TB infection and
disease.
Occupational Exposure
Exposure to TB in the health care setting has long been considered
an occupational hazard. With the steady
[[Page 54176]]
decline in reported TB cases from 1953 to 1985, some of the concern for
occupational exposure and transmission also declined. However, from
1985 to 1992 the number of reported cases of TB increased. In addition,
in recent years, several outbreaks of TB among both patients and staff
in hospital settings have been reported to the CDC. These outbreaks
have been attributed to several factors: (1) Delayed recognition of
active TB cases, (2) delayed drug susceptibility testing, (3)
inadequate isolation of individuals with active TB (e.g., lack of
negative pressure ventilation in isolation rooms, recirculation of
unfiltered air, and allowing infectious patients to freely move in and
out of isolation rooms), and (4) performance of high-risk procedures on
infectious individuals under uncontrolled conditions (Ex. 7-50). In
addition to hospitals, outbreaks of TB have also been reported among
the patients, clients, residents and staff of correctional facilities,
drug treatment centers, homeless shelters and long-term health care
facilities for the elderly. The factors contributing to the outbreaks
in these other occupational settings are very similar to those factors
contributing to the outbreaks in hospital settings (i.e., delayed
recognition of TB cases and poor/inadequate ventilation for isolation
areas).
The following is a discussion of some of the studies that have
examined occupational transmission of TB. A large proportion of the
available information comes from exposures occurring in hospitals, in
part because this occupational setting has been recognized for many
years as an area of concern with regards to the transmission of TB.
However, in more recent years this concern has spread to other
occupational settings which share factors identified in the hospital
setting as contributing to the transmission of disease. The following
sections will include a discussion of some of the historical data from
the hospital setting, as well as the more recent data that have been
developed in hospitals and other occupational settings where the
transmission of TB has occurred as a result of the recent resurgences
in the number of active TB cases.
Hospitals--Prior to 1985
Even prior to the recent resurgence of TB in the general
population, studies have shown an increased risk of transmission of TB
to health care workers exposed to individuals with infectious TB. These
studies clearly demonstrate that in the absence of appropriate TB
control measures (e.g., lack of early identification procedures, lack
of appropriate engineering controls), employees exposed to individuals
with infectious TB have become infected and in some cases have
developed active disease.
In 1979, Barrett-Connor (Ex. 5-11) examined the incidence of TB
among currently practicing physicians who graduated from California
medical schools from approximately 1950 to 1979. Through mailed
questionnaires, physicians were asked to provide information that
included their year of graduation from medical school, BCG vaccination
history, history of active TB, results of their tuberculin skin
testing, and the number of patients they were exposed to with active TB
within the past year. They were also asked to classify themselves as
tuberculin positive or negative and to indicate the year of the last
negative and first positive tuberculin test.
Of the 6425 questionnaires mailed out, 4140 responses were received
from currently practicing physicians. Twelve percent of the physicians
had received the BCG vaccine. Sixty-one percent of the unimmunized
physicians, who also had no history of active tuberculosis, considered
themselves to be tuberculin negative. A total of 1542 (42%) reported
themselves as having a positive response to the tuberculin skin test,
with approximately 44 percent of those tuberculosis infections
occurring before entering medical school. Of those infections occurring
before entering medical school, approximately eight percent were
reported as having been a result of contact following work experience
in the hospital prior to entering medical school. For those physicians
infected either during or after medical school, the sources of
infection were reported as occurring as a result of a known patient
contact (45.1%), an unknown contact (41.5%) and a non-patient contact
(13.4%). In some cases, the nonpatient contact was reported as another
physician or another hospital employee. Approximately one in ten of the
physicians infected after entry into medical school developed active TB
disease.
The authors also examined the incidence of infection, measured as
the conversion rates in those remaining negative at the end of
different time intervals (e.g., the last three years of medical school
and five to 10 years after graduation). This examination indicated that
from 1950 to 1975, there was a 78% decrease in tuberculin conversion
rates despite the expanding pool of susceptible medical students (i.e.,
an increasing number of medical students who were tuberculin negative).
Yet despite this overall decrease in infection rates over a 25 year
period, tuberculin conversion rates among recent graduates exceeded 1%
per year and age-specific infection rates among all the physicians
studied were more than twice that of the U.S. population at comparable
ages. The authors did not obtain information from the physicians on
what type of infection control measures were being used in the
facilities where they acquired their infections.
A similar analysis by Geisleler et al. (Ex. 7-46) evaluated the
occurrence of active tuberculosis among physicians graduating from the
University of Illinois medical school between the years 1938 and 1981.
This study, also conducted by questionnaire, reported that among 4575
physicians questioned, there were 66 cases of active TB, of which 23%
occurred after 1970. Sixty-six percent of the cases occurred within 6
years of graduation. In addition, the authors reported that in most
years the incidence of TB was greater among these physicians than the
general population.
Weiss (Ex. 7-45) examined tuberculosis among student health nurses
in a Philadelphia hospital. From 1935 to 1939, before the introduction
of anti-TB drugs and the beginning of the general decline of TB in the
United States, 100% conversion rates were observed among those students
who were initially tuberculin negative. For example, of 643 students
admitted, 43% were tuberculin negative. At the end of only 4 months,
48% were tuberculin positive. At the end of 1 year, 85.9% were
tuberculin positive and by the end of the third year 100% were
positive. Of those students who converted during their student nursing
tenure, approximately 5 percent developed active TB disease.
A decline in the rate of infection was observed over the next 36
years among student nurses at this hospital. The rates of infection
were followed for ten classes of student nurses from 1962 to 1971. The
students had little contact with patients during their first year but
spent 4 weeks of their second year of training on the tuberculosis
wards. Among those students initially tuberculin negative, the average
conversion rate was 4.2% over the nine year period, ranging from 0 to
10.2%. Of the students who converted, 0.6% developed active TB disease.
The authors attributed the decreases in conversion rates to not only
the general decrease in TB disease in the community, but also to the
increased efficiency of surveillance of patients entering the hospital
for the early identification of potential cases of TB and the increased
efficiency of isolation
[[Page 54177]]
for TB patients. Despite the dramatic decreases in conversion rates
among these student nurses, conversion rates were observed at levels as
high as 10% for a given year, indicating that while the infection rates
had decreased substantially since 1939, there still remained a
significant amount of occupational transmission of TB in 1971.
Moreover, this study shows that short term exposure, i.e., 4 weeks, is
capable of infecting hospital employees.
Similar rates of conversion among hospital employees initially
tuberculin negative were observed in a 1977 study by Ruben et al. (Ex.
7-43) which analyzed the results of a tuberculin skin testing program
31 months after its inception at a university hospital in Pittsburgh.
Of 626 employees who were tested twice with the tuberculin skin test,
28 (4.5%) converted from negative to positive. The employees were
classified as either having a ``presumed high degree of patient
exposure'' or a ``presumed low degree of patient exposure''. Employees
presumed to have high patient exposure included nurses, X-ray and
isotope laboratory personnel and central escort workers. Employees
presumed to have low exposure included secretaries, persons in
housekeeping and dietary work, and business office, laundry and central
supply personnel. The rates of conversion for employees with presumed
high exposure (6%) and for employees with presumed low exposure (8%)
were not significantly different. However, this study excluded
physicians and medical and nursing students. These groups of employees
would also presumably have had high exposure to patients since they are
often the hospital staff most directly involved in administering
patient care. Had these employees been included the number of
conversions among employees with presumably high exposure may have been
significantly increased.
The study was not designed to determine the source of exposure for
any of the employees who converted. However, the authors suggested that
the high level of conversions among those employees with presumed low
exposure to patients may have resulted from exposures at home. A
majority of this group was comprised of housekeeping staff who were of
low socio-economic status. The authors also suggested that unrecognized
cases of tuberculosis may be playing an important role in the
occupational transmission of TB in the hospital.
Unrecognized cases of TB have been shown to play a significant role
in the outbreak of TB in a general hospital. In 1972, Ehrenkranz and
Kicklighter (Ex. 5-15) reported a case study in which 23 employees
converted after exposure to a patient with an undetected case of
tuberculosis bronchopneumonia. In this study, the source case was an
individual who was admitted to the emergency room with pulmonary edema.
Upper lobe changes of the lung were noted in the chest X-ray, and TB
was mentioned as a possible cause. However, no sputum cytology was
conducted. The patient spent 3 hours in the emergency room, 57 hours in
a private room and another 67 hours in intensive care until his death.
Treatment of the patient included intubation with an endotracheal tube
and vigorous nasotracheal suctioning. It was only upon microscopic
examination of tissue samples of the lung and lymph nodes after the
autopsy of the patient that tuberculosis mycobacteria were detected.
Employees who worked in the emergency room, the intensive care unit
and on the floor of the private room (NW 3) and who were also
tuberculin negative before the admission of the patient, were retested
to detect possible conversion. In addition, 21 initially tuberculin
negative employees on an adjacent floor (NW 2) were also retested. Of
the 121 employees tested, 24 were identified as having converted to
positive status (21 working on NW 3, 2 working in the intensive care
unit and 1 working on NW 2). No conversions were observed among those
working in the emergency room.
The employees who were retested were classified as either having
close contact (e.g., providing direct care), little contact (e.g., more
distant contact), unknown contact (e.g., no record or recollection of
contact) or indirect contact (e.g., in the same room a day or two after
the patient's stay). Conversions occurred in 50% (13 of 26) of those
employees with close contact, 18.5% (6 of 33) of those with little
contact, 21.4% (3 of 14) of those with unknown contact and 3.7% (1 of
29) of those with indirect contact.
While the majority of conversions seems to have occurred in those
employees on NW 3 who had close or little contact, there also were
employees with more distant contact who were infected. An analysis of
the ventilation of NW 3 indicated that the central air conditioning
recycled 70% of the air with no high efficiency filter and no record of
balancing the air conditioning system, thus allowing the air from the
patients' rooms to mix with and return to the central corridor air. In
addition, smoke tube tests detected direct air flow from the patients'
rooms to the hall corridor. Perhaps the more important factor was that
the patient was not diagnosed with infectious TB until after his death,
by which time he had already infected 24 employees.
These earlier studies illustrate that despite the decrease in TB
morbidity since the advent of anti-tuberculosis drugs in the 1940's,
occupational transmission of TB continues to be a problem. In addition,
while many improvements have been made in infection control procedures
for TB in hospitals, evidence of occupational transmission of TB
continues to be reported.
Hospitals--1985 to Present
As discussed above, the transmission of TB has been well
established as an occupational hazard in the hospital setting. Many
improvements were made in infection control practices. However, the
resurgence in TB from 1985 to 1992 has brought to attention the fact
that many TB control measures have not been implemented or have been
inadequately applied. These studies demonstrate that TB continues to be
an occupational hazard in the hospital setting. In addition, similar to
the earlier studies, the more recent data show that the lack of early
identification procedures and the lack of appropriate ventilation,
performance of high-hazard procedures under uncontrolled conditions and
the lack of appropriate respiratory protection have resulted in the
infection of employees and in some cases the development of active
disease. The more current outbreaks are even more troubling due to the
emergence of multidrug-resistant forms of TB disease, which in some
cases have resulted in fatality rates approaching 75%.
In a 1985 study, Chan and Tabak (Ex. 7-3) investigated the risk of
TB infection among physicians in training at a Miami hospital. In this
study a survey was conducted among 665 physicians in training who were
in their first four years of postgraduate training. Only 404 responded
to the survey, of which 13 were illegible. Another 72 were excluded
because they had received the BCG vaccination. Of the remaining 319
physicians, 55 were tuberculin positive.
Of the 279 who were tuberculin negative at the beginning of their
post graduate training, 15 were excluded because they had more than
four years of training and 43 were excluded because they had not had
repeat skin tests. Of the 221 remaining available for evaluation, 15
converted to positive tuberculin status, of which two developed active
disease.
The overall conversion rate for these physicians was 6.79%. In
addition, the
[[Page 54178]]
authors observed a positive correlation between the rate of conversion
and the duration of postgraduate training. The conversion rate
increased with the duration of training, beginning with a cumulative
percentage of conversion of 2.06% in the first year, 8.62% in the 2nd
year, 11.11% in the third year and 14.29% in the fourth year, resulting
in a linear conversion rate of 3.96% per year. As noted by the authors,
this linear increase suggests the hospital environment as the source of
the infection. In addition, the prevalence rate of conversions in the
hospital (17.24%) was much higher than would have been expected in the
community for individuals of the same age.
The authors suggested that these high rates of conversion may have
been a result of the fact that the hospital in this study encounters 5
to 10 times more active TB cases than most other urban hospitals. In
addition, the physicians in training also are expected to be the first
in line to perform physical evaluations and evaluate body fluids and
secretions. While the authors did not go into detail about what, if
any, TB infection control precautions were taken by these physicians in
training, they did note that the evaluation of body fluids and
secretions was often done in poorly ventilated and ill-equipped
laboratories.
Increased rates of conversion were observed among employees in a
New Orleans hospital in a 1986 study by Ktsanes et al. (Ex. 7-6).
Similar to Miami, New Orleans also has a high rate of TB in the
community. This study examined the skin test conversions among a cohort
of 550 new employees who were followed for five years after assignment
to the adult inpatient services. Of these 550 employees who were
initially tuberculin negative, 17 converted to positive status over the
five-year study period, resulting in an overall five-year cumulative
conversion probability of 5.2%.
Regression analyses were done to examine potential contributing
factors. Factors examined in the regression model included race, job,
age at employment, and department. Only race (i.e., black vs. white
employees) and job (i.e., nursing vs. other jobs) were found to be
associated with skin test conversion. To further examine the potential
job effect, conversions among blacks in nursing and blacks in other
jobs were compared. Overall, the cumulative probability of converting
was higher among blacks in nursing, suggesting that the acquired
infections resulted from employment at the hospital rather than from
the community at large. The authors thus concluded that there is an
increased risk of occupational transmission of TB in TB-prevalent areas
for those in close patient contact jobs.
In 1989, Haley et al. (Ex. 5-16) conducted a case study of a TB
outbreak among emergency room personnel at a Texas hospital. In this
study, a 70 year old male diagnosed with pulmonary TB and undergoing
treatment was diverted, due to respiratory arrest, to Parkland Memorial
Hospital while in route to another hospital. The man was admitted to
the emergency room for approximately 4 hours until he was stabilized.
Afterwards, the patient was placed in an intensive care unit, where he
remained for 2 months until his death.
Six cases of active TB developed among emergency room employees
after exposure to the TB patient, i.e., the index case. Five of these
were among nurses who recalled contact with the index patient and a
sixth case was an orderly who may have been infected from one of the
employee TB cases. In addition, a physician exposed while administering
treatment in the intensive care unit also developed active disease.
Skin test conversions were evaluated for the 153 employees of the
emergency room. Of 112 previously negative employees, 16 had positive
skin tests, including 5 nurses diagnosed with active TB. Fifteen of the
conversions were a result of exposure to the index case. Skin tests
were also evaluated for physicians in the intensive care unit. Of 21
resident physicians, two of whom had intubated the index patient, five
had newly positive reactions to the tuberculin skin tests. One of the
remaining three residents later developed active disease.
The authors attributed the outbreak to several factors. First, the
index case had a severe case of pulmonary TB in which he produced
copious amounts of sputum. Second, sixty percent of the emergency room
air was recirculated without filtration adequate to remove TB bacilli,
allowing for the recirculation of contaminated air. Finally, employees
in the emergency room were provided surgical masks that were
ineffective for protecting against transmission of airborne TB droplet
nuclei. This study illustrates that the lack of effective measures for
controlling TB transmission can result in the infection and development
of active disease in a relatively high number of employees even after
exposure to only one case of active TB.
Similarly, the lack of effective controls while performing high-
hazard, cough-inducing procedures on individuals with infectious TB has
also been shown to result in an increased risk of TB transmission. A
1990 report by Malasky et al. (Ex. 7-41) investigated the potential for
TB transmission from high-hazard procedures by examining tuberculin
skin test conversion rates among pulmonary physicians in training. In
this study, questionnaires were sent annually, for 3 years, to training
programs located in the top 25 cities for TB in 1983. The purpose of
the study was to compare the conversion rates of pulmonary disease
fellows to the conversion rates of infectious disease fellows. It was
presumed that both groups have contact with patients with TB but that
pulmonary disease fellows are usually more involved with invasive
procedures such as bronchoscopies. Information requested on the
questionnaires included the type of fellowship (i.e., pulmonary or
infectious disease fellow), prior tuberculin skin test status,
tuberculin status by the Mantoux technique at the end of the 3 year
fellowship program, history of BCG vaccination, age, sex and ethnicity.
In addition, the pulmonary disease fellows were asked to give
information on the number of bronchoscopies they performed and their
use of masks during the procedure.
Fourteen programs submitted data that were usable. Only programs
that had both pulmonary and infectious disease fellows in the same
system were used for the study. From this information, it was observed
that 7 of 62 (11%) of the pulmonary fellows at risk converted their
tuberculin skin test from negative to positive during the two year
training period. In contrast, only 1 of 42 (2.4%) of the infectious
disease fellows converted. The expected conversion rate from previous
surveys was 2.3%. In addition, the pulmonary disease fellows were
grouped according to tuberculin skin status. Skin test status was
evaluated for its relationship to the number of bronchoscopies
performed and the pattern of mask usage. No correlations were found
with these factors and tuberculin skin status at the end of the
fellowship. The authors suggested that the lack of correlation between
mask usage during bronchoscopies and skin test conversion implies that
masks worn by physicians may be inadequate. While little information
was presented to evaluate this suggestion, the study does suggest that
high-hazard procedures such as bronchoscopies that induce coughing,
performed under uncontrolled conditions, present a risk for TB
transmission.
Pearson et al. (1992) conducted a case-control study to investigate
the factors associated with the development of MDR-TB among patients at
a New
[[Page 54179]]
York City hospital (Ex. 5-24). As a part of this study, tuberculin skin
test conversion rates were compared among health care workers assigned
to wards where patients with TB were frequently admitted (e.g., HIV
unit, general medical ward, respiratory therapy) or rarely admitted
(operating room, orthopedic ward, outpatient clinic, psychiatry ward).
In addition, infection control procedures and ventilation systems were
evaluated.
Of 79 health care workers who were previously negative, 12 (15%)
had newly positive skin tests. Those health care workers who were
assigned to wards where patients with TB were frequently admitted were
more likely to have skin test conversions (i.e., 11 of 32) than health
care workers assigned to wards where patients with TB were rarely
admitted (i.e., 1 of 47).
Evaluations of the infection control procedures and ventilation
systems revealed that patients who were receiving isolation precautions
for suspected or confirmed TB were allowed to go to common areas if
they wore a surgical mask. However, many of the patients did not keep
their masks on when out of their rooms. In addition, neither the
isolation rooms nor rooms used for cough-inducing procedures were under
negative pressure, thus allowing contaminated air to exhaust to the
adjacent corridors.
Edlin et al. (1992) (Ex. 5-9) investigated an outbreak of MDR-TB in
a New York hospital among patients with acquired immunodeficiency
syndrome (AIDS). This study compared the exposure period of AIDS
patients diagnosed with MDR-TB to the exposure period of AIDS patients
with drug-susceptible TB. The date of diagnosis was defined as the date
the sputum sample was collected from which tuberculosis bacteria were
grown in culture. Patients were assumed to be infectious two weeks
before and two weeks after the date of diagnosis. The period of
exposure was the period in which the patient may have been infected
with TB. Because of the rapid progression from infection to disease,
the exposure period was defined as 6 months preceding the date of
diagnosis, excluding the last two weeks.
The patients with MDR-TB were found to be more likely to have been
hospitalized during their exposure periods. Those who were hospitalized
were more likely to have been on the same ward and on the same day as a
patient with infectious TB and were more likely to have been near a
room housing an infectious patient. Examination of the infectious
patients' rooms revealed that only 1 of 16 rooms had negative pressure.
Based on this evidence, the authors concluded that the observed cases
of MDR-TB were a likely result of infections acquired in the hospital
(i.e., primary TB) rather than as a result of the reactivation of
infections acquired in the past. The authors attributed these
nosocomial infections to the lack of adherence to recommended infection
control procedures.
While the primary focus of this study was to investigate the
transmission of TB among patients, the increased likelihood of
nosocomial infections among patients in the hospital would seem equally
likely to apply to health care workers working in the same environment.
A survey of tuberculin skin test conversions revealed an 18% conversion
rate for health care workers who previously had negative skin tests and
were present during this outbreak of MDR-TB. Although no statistics
were reported, the authors stated that the pattern of skin test
conversions suggested an ongoing risk over time rather than a recent
increase during the outbreak period.
Based on an earlier 1990 report from the CDC (Ex. 5-22), Beck-Sague
et al. 1992 (Ex. 5-21) conducted a case-control study to investigate an
outbreak of MDR-TB among the staff and patients in a HIV ward and
clinic of a Miami hospital. As part of the overall study the authors
compared the skin test conversion rates of health care workers in the
HIV ward and clinic to the skin test conversion rates of health care
workers in the thoracic surgery ward where TB patients were rarely
seen. In addition, the authors also evaluated the relationship between
the presence of patients with infectious MDR-TB and patients with
infectious drug-susceptible TB on the HIV ward and the risk of skin
test conversion among the HIV ward health care workers. Infection
control procedures in the HIV ward and clinic were also examined.
All patients with suspected or confirmed TB were placed in
isolation. However, some patients whose complaints were not primarily
pulmonary and whose chest X-rays were not highly suggestive of TB were
not initially suspected of TB and were not placed in isolation.
Patients who were admitted to isolation rooms were allowed to leave TB
isolation 7 days after the initiation of chemotherapy regardless of
clinical or bacteriologic response. Thus, in some instances, patients
with MDR-TB were allowed to leave isolation while they were still
infectious, before drug resistance was recognized. In addition,
patients in isolation rooms sometimes left the doors open, left their
rooms, and/or removed their masks while outside their rooms. Patients
with TB who were readmitted to the HIV ward and who were receiving
anti-TB drugs were not admitted to isolation. In some cases, these
patients were later found to have infectious MDR-TB.
An environmental assessment of the ventilation revealed that among
23 rooms tested with smoke tubes, 6 had positive pressure and many of
the rooms under negative pressure varied from negative to positive
depending on the fan setting and whether the bathroom door was open.
Aerosolized pentamidine administration rooms were also found to have
positive pressure relative to adjacent treatment areas. In addition,
the sputum induction rooms were found to recirculate air back to the
HIV clinic.
Skin test conversions were evaluated for all health care workers
(i.e., nurses and clerical staff) who tested negative on the tuberculin
skin test before the outbreak period, March 1988 through April 1990.
Health care workers on the HIV ward and in the HIV clinic exhibited a
significantly higher rate of skin test conversion than health care
workers on the thoracic surgery ward (e.g., 13/39 vs. 0/15). Ten of the
conversions occurred among the 28 health care workers in the HIV ward.
Among these health care workers, the authors reported a significant
correlation between the risk of infection in health care workers and
the number of days that patients with infectious MDR-TB were
hospitalized on the HIV ward. No correlation was observed between the
risk of infection among health care workers on the HIV ward and the
number of days that patients with infectious drug-susceptible TB were
hospitalized on the ward.
Based on skin test conversions and the evaluation of infection
control practices in the HIV ward and clinic, the authors concluded
that the health care workers most likely were infected by patients on
the HIV ward with MDR-TB. The factors most likely contributing to this
increased risk of infection included: (1) The prolonged infectiousness
and greater number of days that patients with infectious MDR-TB were
hospitalized, (2) the delayed recognition of TB and failure to suspect
infectious TB in patients receiving what proved to be ineffective anti-
TB treatment, (3) the inadequate duration of, and lapses in, isolation
precautions on the HIV ward, and (4) the lack of negative pressure
ventilation in isolation and treatment rooms. While the evidence in
this study primarily points to the transmission of MDR-TB
[[Page 54180]]
from patients to health care workers, many of the problems identified
with infection control procedures and ventilation would also increase
the risk of acquiring drug-susceptible TB.
In addition to MDR-TB outbreak investigations in Miami, in 1993 the
CDC reported an outbreak in New York City in which health care workers
became infected after being exposed to patients with MDR-TB (Ex. 6-18).
In this investigation, for the period December 1990 through March 1992,
32 patients were identified with MDR-TB. Twenty-eight of these patients
had documented exposure to an undiagnosed infectious MDR-TB patient
while all of them were in the HIV ward of the hospital.
During November 1991, health care workers who were assigned to the
HIV inpatient unit and who were also previously negative on the
tuberculin skin test, were given an additional skin test. Of 21 health
care workers tested, 12 (57%) had converted to positive status (7
nurses, 4 aides and 1 clerical worker). None of the health care workers
had used respiratory protection.
An investigation of infection control practices revealed that of 32
patients with MDR-TB, 16 were not initially suspected of TB and in
these cases isolation precautions either were not used or were
instituted late during the patients' hospitalization. In addition,
patients who were admitted to isolation frequently left their rooms and
when in their room the doors were frequently left open. Moreover, all
rooms were found to be under positive pressure relative to the hall.
Thus, similar to the findings in Miami, the results of this study
indicate that the inability to properly isolate individuals with MDR-TB
and also the use of inadequate respiratory protection may increase the
risk of infection among health care workers.
Undiagnosed cases may also present a significant source for
occupational transmission of TB. A case study by Cantanzaro (Ex. 5-14)
described an outbreak of TB infection among hospital staff at a San
Diego hospital where the hospital staff were exposed to a single
patient with undiagnosed TB. In this case, a 64 year old man suffering
from generalized seizures was transferred from a local jail to the
emergency room and later admitted to a four bed intermediate care unit.
While in the intermediate care unit he was treated with anticonvulsants
but continued to have seizures accompanied with vomiting. He was
therefore placed in intensive care where he underwent a variety of
procedures including bronchoscopies and endotracheal intubation. During
his stay, he received frequent chest therapy and suctioning. Three
sputum samples were taken from the patient for smears and cultures. All
AFB smears were negative. However, two cultures were positive for
tuberculosis.
Despite the presence of positive cultures the patient was not
diagnosed with active TB. The problem was not recognized until a
physician on staff later developed symptoms of malaise and slight cough
and requested a tuberculin skin test and was found to be positive.
Because the physician had been tuberculin negative 8 months earlier, a
contact investigation was initiated. As a part of this investigation,
all employees who previously had negative tuberculin tests and who also
worked in the intermediate and intensive care units where the patient
had been treated were given repeat skin tests. Of 45 employees who
previously had negative tuberculin skin tests, 14 (31%) converted to
positive status (6 physicians, 3 nurses, 2 respiratory therapists and 1
clerk). Ten of these conversions were among the 13 previously
tuberculin negative staff members who were present at the time
bronchoscopies were conducted (10/13=76.9%). Four of the conversions
were among 32 susceptible staff members who were not present at the
bronchoscopies (4/32=12.5%). The author thus concluded that being
present during the bronchoscopy of the patient was a major risk factor
in acquiring the TB infection. However, the evidence did not show a
significant correlation between skin test conversion and the type of
exposure, i.e., close (administered direct contact) versus casual (in
the room) contact. Thus, people who were present in the room during the
bronchoscopy had an equal risk of infection as those administering
direct patient care, presumably, as the author suggests, because
droplet nuclei can disperse rapidly throughout the air of a room.
Similarly, Kantor et al. (Ex. 5-18) reported an outbreak of TB
infection among hospital staff exposed to a single undiagnosed case of
TB. The index case in this investigation was a 50 year old man who was
admitted for lung cancer and was receiving chemotherapy, steroids and
radiation treatment. After a month of treatment, the patient complained
of a cough and chest pain and was found to have emphysema requiring
additional drug treatment and a chest tube. However, even after the
emphysema resolved, the patient complained of weakness, loss of
appetite and fever. A sputum culture and smear were conducted for
mycobacteria and found to be negative. Lung X-rays were found to be
irregular but were attributed to the lung cancer. Upon his death the
autopsy revealed extensive necrosis in the lung but tuberculosis was
not suspected. Thus, no cultures for mycobacteria were performed and no
infection control procedures were initiated. It was only upon
histological examination of tissue samples one month later that the
presence of TB was confirmed. Five months later one of the staff
performing the autopsy developed active TB. His only history of
exposure was to the index case.
As a result, a contact investigation was initiated for hospital
personnel who had shared air with the patient during his stay,
including the autopsy staff. Of susceptible hospital staff (i.e., those
not previously found to react positive to the tuberculin skin test),
infection developed in 9 of 56 (16%) exposed employees (4 autopsy
staff, 4 nursing staff and 1 radiology staff). Only 3 of 333 unexposed
personnel were found to have converted to positive tuberculin status at
the hospital during the same period of investigation, thus indicating a
17.8 fold increase in the infection rate for the exposed group.
Undiagnosed cases of TB at time of autopsy were also indicated as
the likely cause for development of active TB among staff and students
in an autopsy room in a Swedish hospital (Ex. 5-19). In this study,
three medical students and one autopsy technician, who were present
during the autopsy of a patient with previously undiagnosed pulmonary
TB, developed active TB. Both the medical students and the autopsy
technician had previously received the BCG vaccine but none had any
other known contact with a tuberculosis subject. Thus, it was concluded
that the tuberculosis infections were most likely to have been
transmitted during the autopsy. The findings of this study further
illustrate the risks that undiagnosed cases of active TB present to
health care workers. The lack of recognition of an active case of TB
often results in a failure to initiate appropriate infection control
procedures and provide appropriate personal protective equipment. In
addition, this study illustrates that, while TB is most often
transmitted by individuals with infectious pulmonary TB who generate
droplet nuclei when they cough or speak, the autopsy procedures on
deceased individuals with pulmonary TB may also aerosolize bacteria in
the lungs and generate droplet nuclei.
Exposure during autopsy procedures was also suspected as a possible
route of TB transmission in an upstate New
[[Page 54181]]
York Medical Examiner's Office (Ex. 7-152). This Medical Examiner's
Office conducted autopsies on deceased inmates from upstate New York
prisons. In 1991, the same year that an outbreak of MDR-TB occurred
among inmates from an upstate New York prison, the Medical Examiner's
office conducted autopsies on 8 inmates with TB, six of whom had
infectious MDR-TB at death and who were also HIV positive and had
disseminated TB disease.
Skin tests were administered to employees who had worked for at
least one month during 1991 at the Medical Examiner's Office. Among 15
employees who had originally tested negative on a baseline skin test, 2
were found to have converted. These two employees worked as morgue
assistants and had recent documented exposure to persons with extensive
disseminated MDR-TB. No potential exposure to TB outside the Medical
Examiner's Office could be found.
The autopsy area of the office had a separate ventilation system.
However, air was returned to a common air plenum, allowing the air to
mix between the autopsy area and other areas of the office. In
addition, the autopsy room was found to be at positive pressure
relative to the adjacent hallway. Employees performing or assisting at
autopsies on persons known to be infected with HIV were required to
wear plastic gowns, latex gloves and surgical masks. Particulate
respirators were not required until November of 1991, after the
installation of germicidal UV lamps. However, this was after the last
MDR-TB autopsy. This study suggests that the conversion of these two
morgue assistants occurred as a result of exposure to aerosolized M.
tuberculosis resulting from autopsy procedures, either as a result of
participation in an autopsy in the autopsy area or from exposure to air
contaminated with aerosolized M. tuberculosis that was exhausted into
other areas of the Medical Examiner's Office.
In addition to autopsy procedures, other procedures, such as the
irrigation of abscesses at sites of extrapulmonary TB, can result in
the generation of droplet nuclei. An outbreak investigation in an
Arkansas hospital (Ex. 5-17) reported the transmission of TB among
hospital employees exposed to a patient with a tuberculous abscess of
the hip and thigh. In this study, the source case was a 67 year old man
who was admitted to the hospital with a fever of unknown origin and
progressive hip pain. The patient did not present any signs of
pulmonary TB; however, the examination of soft tissue swelling in the
hip area revealed an abscess that required drainage and irrigation. Due
to the suspicion of TB, specimens for AFB smear and culture were
obtained and the patient was placed in isolation. While in isolation,
drainage from the abscess continued and irrigation of the abscess
cavity was initiated on an 8-hour schedule. After four days, acid fast
bacilli were observed in the AFB smears and TB therapy was begun. The
patient remained in isolation until his death except for three days
that he spent in the Intensive Care Unit (ICU) due to high fever.
An investigation of skin test surveys among the hospital employees
revealed 55 skin test conversions among 442 previously nonreactive
employees and 5 conversions among 50 medical students. In addition, 5
of the employees who had conversions also had active TB, including one
who developed a tuberculous finger lesion at the site of a needle-stick
injury incurred during the incision and drainage of the patient's
abscess. All the skin test converters, except for two, recalled
exposure to the source case. Of the 442 susceptible employees, 108
worked at least one day on one of the floors where the patient stayed
(i.e., the surgical ward, the medical floor of the patient's room and
the ICU). Four (80%) of 5 surgical suite employees who had direct
contact with the patient through their assistance with the incision and
irrigation of the patient's abscess had skin test conversions. In
addition, 28 (85%) of 33 employees on the general medical floor and 6
(30%) of 20 ICU employees had skin test conversions. All those
employees converting recalled exposure to the patient, some of whom had
no direct contact with the patient.
Environmental studies revealed that two of the areas in which the
patient stayed during his hospitalization did not have negative
pressure. The isolation room was under positive pressure relative to
adjacent rooms and the corridor. In addition, the patient's cubicle in
the ICU had neutral pressure relative to the rest of the ICU. Employees
in these two areas had skin test conversions even in cases where there
was no direct patient contact. The lack of negative pressure was
thought to have significantly contributed to the dispersion of droplet
nuclei generated from the irrigation of the tuberculous abscess. In the
surgical ward, air was directly exhausted to the outside. However, all
employees present in the surgical ward when the patient was being
treated had direct contact with the patient. There was no indication
that the surgical staff had taken any special infection control
precautions or had worn any personal protective equipment.
Thus, similar to other outbreak investigations, the lack of
appropriate ventilation and respiratory protection stand out as the key
factors in the transmission of TB to employees who are exposed to
individuals with infectious TB. Moreover, this particular case study
demonstrates that certain forms of extrapulmonary TB in conjunction
with aerosolizing procedures, e.g., the irrigation of a tuberculous
abscess, have the potential for presenting significant airborne
exposures to M. tuberculosis.
Other aerosolizing procedures have also shown evidence of
presenting airborne exposures to M. tuberculosis. For example, tissue
processing was associated with the skin conversion of two pathologists
working at a community hospital in California (Ex. 6-27). In this case
study, after autopsy, a 62 year old man who had died from bronchogenic
carcinoma was discovered to have a caseating lung lesion. A stain
revealed a heavy concentration of acid-fast bacilli, which were
identified in culture as M. tuberculosis. As a result, a contact
investigation was initiated.
This investigation found twenty employees who had contact with the
patient, including two pathologists and a laboratory assistant. All
were given a tuberculin skin test and found to be negative. However,
after follow-up skin testing three months later, the two pathologists
had converted. Other than contact with the source case, the two had no
other obvious sources of infection. One of the pathologists had been
present at the autopsy. Both pathologists were present when the frozen
lung sections were prepared. During this process, the lung tissue was
sprayed with a compressed gas coolant, which created a heavy aerosol.
Masks were not routinely worn during this tissue processing. The
investigators suspected that this aerosol promoted the transmission of
TB and was the likely cause of the observed infections.
While much of the health effects literature has focused on
outbreaks of TB or MDR-TB, a more recent study investigated the status
of infection control programs among ``non-outbreak'' hospitals (Ex. 7-
147). Investigators from the Society of Health care Epidemiology of
America (SHEA) and the CDC surveyed members of SHEA to assess
compliance in the respondents' hospitals with the 1990 CDC Guidelines
for Preventing the Transmission of TB in Health Care Facilities for the
years 1989 to 1992. The survey included questions on tuberculin skin
testing programs (e.g., frequency of testing,
[[Page 54182]]
positivity at hire, and percent newly converted), AFB isolation
capabilities (e.g., negative pressure, air changes per hour, HEPA
filtration) and respiratory protection.
The survey showed that of the 210 hospitals represented by the SHEA
members' survey results, 193 (98%) admitted TB patients from 1989 to
1992, 40% of which had one or more patients with MDR-TB. In addition,
the proportion of hospitals caring for drug susceptible TB patients
rose from 88% to 92% and the proportion of hospitals caring for MDR-TB
patients rose from 5% to 30%. While the number of hospitals caring for
TB patients increased, the majority of those hospitals cared for a
small number of patients. In 1992, approximately 89% of the hospitals
reported 0 to 25 patients per year, while approximately 5% reported
greater than 100 patients per year.
Few hospitals reported routine tuberculin skin testing for each of
the years surveyed. For example, while 109 (52%) of the responding
hospitals reported tuberculin skin test results for at least one of the
years from 1989 to 1992, only 63 (30%) reported results for each of
these years. When examining the conversion rates over time from 1989 to
1992, the investigators limited their analysis to the 63 hospitals
reporting skin test data for each of these 4 years. Among these
hospitals the median percentage of employees newly converting to
positive skin test status remained constant over the 4 year period at
approximately 0.34% per year (i.e., 3/1000 per year). However, when
including all hospitals in the analysis, from 1989 to 1992, the number
of hospitals reporting conversion rates increased from 63 to 109 and
the conversion rates increased from 0.26% (i.e., 2/1000) to 0.50%
(i.e., 5/1000).
With regard to AFB isolation capabilities, 62% of 181 responding
hospitals reported that they had isolation facilities consistent with
the 1990 CDC TB Guidelines (i.e., single-patient room, negative
pressure, air directly exhausted outside, and 6 air changes
per hour). Sixty-eight percent of the reporting hospitals had isolation
facilities meeting the first three of these recommendations. For
respiratory protection, the majority of health care workers in the
hospitals used surgical masks. However, there was an increase in the
use of dust-mist or dust-mist-fume respirators. The use of dust-mist
respirators increased from 1 to 13% from 1989 to 1992 and the use of
dust-mist-fume respirators increased from 0 to 10% for the same period.
The only use of high efficiency particulate air (HEPA) filter
respirators was by bronchoscopists and respiratory therapists at 4
hospitals.
As a second phase of this investigation, the survey responses were
analyzed to determine the efficacy of the TB infection control programs
among the member hospitals participating in the survey (Ex. 7-148). In
this analysis, the reported conversion rates were compared to reported
infection control measures (i.e., AFB isolation capabilities and
respiratory protection). For purposes of comparison, hospitals were
categorized as having either less than or 6 TB patients,
less than or 437 beds, and admitting or not admitting MDR-TB
patients.
Conversion rates were higher among health care workers from
hospitals with 437 beds than among health care workers from
smaller hospitals (0.9% vs. 0.6%, p0.05). This difference
was more pronounced among ``higher-risk'' health care workers (i.e.,
health care workers including bronchoscopists and respiratory
therapists). ``Higher-risk'' health care workers from hospitals with
437 or more beds had a 1.9% conversion rate compared to a conversion
rate of 0.2% for ``higher-risk'' health care workers from smaller
hospitals. Similarly, health care workers from hospitals where 6 or
more TB patients were admitted per year had higher conversion rates
than health care workers from hospitals with fewer than 6 TB patients
per year (e.g., 1.2% vs. 0.6%).
For hospitals with 6 or more TB patients, conversion rates also
varied depending on the level of TB infection control practices that
were in place in the hospital. For example, among hospitals with 6 or
more TB patients and whose AFB isolation capabilities included at least
single-room occupancy, negative pressure and directly exhausted air,
the conversion rates among health care workers were lower than the
conversion rates among health care workers at hospitals with 6 or more
TB patients but which did not have similar isolation capabilities
(0.62% vs. 1.83%, p=0.03). For respiratory protection, however, no
differences in conversion rates were observed among health care workers
wearing surgical masks (0.94%) and health care workers using submicron
surgical masks, dust-mist respirators or dust-mist-fume respirators
(0.98%). Very few survey respondents reported use of HEPA filter
respirators. For example, only four hospitals reported use of any HEPA
respirators, and these were not the predominant type of respiratory
protection used (Ex. 7-147). Thus, it is not possible to evaluate the
efficacy of these particulate respirators in reducing conversion rates
from the reported survey data.
For hospitals with fewer than 6 TB patients or with fewer than 437
beds, no differences in conversion rates were reported among health
care workers from hospitals that had implemented AFB isolation
capabilities such as single-room occupancy, negative pressure, or
directly exhausted air and those hospitals that had not. The
investigators suggested that this finding may support contentions that
the efficacy of TB infection control measures vary depending on
characteristics of the hospital or community exposure. However, given
the small sample size of the survey, as well as the reduced potential
for exposure in hospitals with fewer than 6 TB patients per year, it
would be difficult to detect any differences in conversion rates among
health care workers from hospitals with or without certain levels of
infection control. Where more opportunity does exist for exposure
(e.g., hospitals with 6 TB patients), this analysis does
show that the implementation of TB infection control procedures can
reduce the transmission of TB among health care workers.
Hospitals--Summary
In summary, the evidence clearly shows that in hospital settings,
employees are at risk of occupational exposure to TB. Various studies
and TB outbreak investigations have shown that employees exposed to
individuals with infectious TB have converted to positive tuberculin
skin status and in some cases have developed active disease. In these
reports, a primary factor in the transmission of TB has been a failure
to promptly identify individuals with infectious TB so that appropriate
infection control measures could be initiated to prevent employee
exposure. In addition, another major factor identified as contributing
to occupational exposures was the lack or ineffective implementation of
appropriate exposure control methods (e.g., lack of negative pressure
in isolation rooms, lack of appropriate respiratory protection for
exposed employees, performance of high-hazard procedures under
uncontrolled conditions). The lack of early identification and
appropriate control measures resulted in the exposure and subsequent
infection of various hospital employees. These employees included not
only health care providers administering direct patient care to
individuals with infectious TB, but also hospital staff providing
support services
[[Page 54183]]
to the infectious individuals, hospital staff working in adjacent areas
of the hospital using shared air, autopsy staff and laboratory staff
working with infected culture and tissue samples.
Other Occupational Settings
While hospitals have been historically recognized as the primary
type of work setting where TB presents an occupational hazard, there
are other work settings where the transmission of TB presents a hazard
to workers. There are a variety of occupational settings in which
workers can reasonably be anticipated to encounter individuals with
active TB as a part of their job duties. Several work settings have
been identified by the CDC where exposure to TB presents an
occupational hazard: correctional facilities, long-term care facilities
for the elderly, homeless shelters, drug treatment centers, emergency
medical services, home-health care, and hospices. Similar to the
hospital setting, these work settings have a higher number of
individuals with active TB than would be expected for the general
population. Many of the clients of these work settings have many
characteristics (e.g., high prevalence of TB infection, high prevalence
of HIV infection, intravenous drug use) that place them at an increased
risk of developing active TB. These types of work settings are also
similar to hospitals in that workers at these sites may also provide
medical services and perform similar types of high-hazard procedures
that are typically done in a hospital setting.
In addition to employees who provide medical services in these
other types of work settings, there are other types of workers (e.g.,
guards, admissions staff, legal counsel for prisoners) who may also be
exposed to individuals with infectious TB. Similar to hospitals, these
work settings have an over-representation of populations at high risk
for developing active TB, e.g., individuals infected with HIV,
intravenous drug users, elderly individuals, and individuals with poor
nutritional status and who are medically underserved. In addition to
having a higher percentage of individuals with TB infection and a
higher percentage of individuals at an increased risk for developing
active TB, many of these work settings also share environmental factors
that facilitate the transmission of TB, such as overcrowding and
inadequate ventilation, which increases the occupational hazard. The
following discussion describes some of the studies available in the
literature that have examined the occupational transmission of TB in
other occupational settings such as those listed above. Not all the
settings listed by the CDC as places where TB transmission may be
likely to occur have been adequately studied and thus can not be
included in this discussion. However, the discussion of the following
sectors clearly demonstrates that the occupational transmission of TB
is not limited to the hospital setting. Occupational settings where
there is an increased likelihood of exposure to aerosolized M.
tuberculosis present the same types of occupational hazards as have
been documented in the hospital setting.
Correctional Facilities
Many correctional facilities have a higher incidence of TB cases
than occur in the general population. For example, the CDC reported
that the incidence of TB among inmates of correctional facilities was
more than three times higher than that for nonincarcerated adults aged
15-64, based on a survey of TB cases in 1984 and 1985 by 29 state
health departments (Ex. 3-33). In particular, among inmates in the New
York correctional system, the TB incidence increased from an annual
average of 15.4 per 100,000 during 1976 to 1978 to 105.5 per 100,000 in
1986 (Ex. 7-80) to 156.2/100,000 for 1990-1991 (Ex. 7-137). Similarly,
in 1987, the incidence of TB among inmates in New Jersey was 109.9 per
100,000 (approximately 11 times higher than the general population in
New Jersey) and in California the incidence of TB among inmates was
80.3 per 100,000 (approximately 6 times higher than that for the
general population for California) (Ex. 3-33). In 1989, the CDC
reported that since 1985, eleven known outbreaks of TB have been
recognized in prisons (Ex. 3-33).
The increased incidence of TB in correctional facilities has been
attributed to several factors (Ex. 7-25). One, correctional facilities
have a higher incidence of individuals who are at greater risk for
developing active TB. For example, the population in prisons and jails
may be dominated by persons from poor and minority groups, many of whom
may be intravenous drug users. These particular groups may also suffer
from poor nutritional status and poor health care, factors that place
them at increased risk of developing active disease. Two, special types
of correctional facilities, such as holding facilities associated with
the Immigration and Naturalization Services, may have inmates/detainees
from countries with a high incidence of TB. For foreign-born persons
arriving in the U.S., the case rate of TB in 1989 was estimated to be
124 per 100,000, compared to an overall TB case rate of 9.5 per 100,000
for the U.S. (Ex. 6-26). In 1995, TB cases reported among the foreign
born accounted for 35.7% of the total reported cases, marking a 63.3%
increase since 1986 (Ex. 6-34). Three, many correctional facilities
have a high proportion of individuals who are infected with HIV. The
CDC reported that in addition to the growing increase in AIDS among
prisoners, the incidence of AIDS in prisons is markedly higher than
that for the U.S. general population. In 1988, the incidence of AIDS
cases in the U.S. population was 13.7 per 100,000 compared to an
estimated aggregate incidence for state/federal correctional systems of
75 cases per 100,000 (Ex. 3-33). Individuals who are infected with HIV
or who have AIDS are at an increased risk of developing active TB due
to their decreased immune capacity. The likelihood of pulmonary TB in
individuals with HIV infection is reflected in the CDC's Revised
Classification System for HIV infection (Ex. 6-30). In this revised
classification system, the AIDS surveillance case definition was
expanded to include pulmonary TB. Moreover, X-rays of individuals
infected with HIV who have TB often exhibit radiographic irregularities
that make the diagnosis of active TB difficult (Exs. 7-76, 7-77, 7-78,
and 7-79). HIV-infected individuals may have concurrent pulmonary
infections that confound the radiographic diagnosis of pulmonary TB. In
addition, it may be difficult to distinguish symptoms of TB from
Pneumocystis carinii pneumonia or other opportunistic infections. This
difficulty in TB diagnosis can result in true cases of active TB going
undiagnosed in this population. Undiagnosed TB has been shown to be an
important cause of death in some patients with HIV infection (Ex. 7-
76). Fourth, environmental conditions in correctional facilities can
aid in the transmission of TB. For example, many prisons are old, have
inadequate ventilation systems, and are overcrowded. In addition,
inmates are frequently transferred both within and between facilities,
thus increasing the potential for the spread of TB infection among
inmates and staff. This increased potential for mobility among inmates
also enhances the likelihood that inmates undergoing therapy for active
disease will either discontinue their treatment or inadequately follow
their prescribed regime of treatment. The inadequacy of their treatment
may give rise not only to relapses to an infectious state of active
disease, but also potentially give rise to strains of MDR-
[[Page 54184]]
TB. These strains of TB have a higher incidence of fatal outcome and
are generally characterized by prolonged periods of infectiousness
during which the risk of infection to others is increased.
The high incidence of TB among the inmate population presents an
occupational hazard to the staff in these types of facilities. Recent
outbreak investigations by the CDC have documented the transmission of
TB to exposed workers. In an investigation of a state correctional
facility in New York for 1991 (Exs. 6-3 and 7-136), eleven persons with
TB were identified (10 inmates and one correctional facility guard).
Nine persons (8 inmates and the guard) had MDR-TB. All eight inmates
were HIV positive. The guard was HIV negative; however, he was also
immunocompromised as a result of treatment for laryngeal cancer. Seven
of the inmates and the guard died from MDR-TB. The eighth inmate was
still alive and receiving treatment for MDR-TB 2 years after being
diagnosed as having the disease. DNA analysis identified the strains of
tuberculosis bacteria from these individuals to be identical.
The investigation revealed that the source case was an inmate who
had been transferred from another prison where he had been previously
exposed to MDR-TB. He arrived at the prison with infectious TB but
refused evaluation by the infirmary staff. This inmate was placed in
the general prison population where he stayed for 6 months until he was
admitted to the hospital where he later died. However, before his
hospitalization, he exposed two inmates living in his cell block who
later developed MDR-TB. These two inmates continued to work and live in
the prison until shortly before their final hospitalization. The other
inmates who subsequently developed MDR-TB had several potential routes
of exposure: social contact in the prison yard, contact at work sites
in the prison, and contact at the prison infirmary where they shared
rooms with other inmates before diagnosis with TB.
The guard who developed MDR-TB had exposure to inmates while
transporting them to and from the hospital. The primary exposure for
this guard apparently occurred when he was detailed outside the
inmates' room during their hospitalization for MDR-TB. The inmates were
hospitalized in an isolation room with negative pressure. However, upon
investigation it was discovered that the ventilation system for the
room had not been working correctly and had allowed air to be exhausted
to the hospital corridors and other patient rooms.
A contact investigation in the prison was conducted to identify
other inmates who might have been exposed during this outbreak of MDR-
TB. Of those inmates with previous negative tuberculin skin tests and
without active disease (306), ninety-two (30%) had documented skin test
conversions. There was no tuberculin skin test program for prison
staff; therefore, conversions among prison employees could not be
evaluated.
The primary factors identified as contributing to this outbreak
were deficiencies in identifying TB among transferred inmates,
laboratory delays, and lapses in isolating inmates with active TB
within the facility. Inmates with symptoms of active disease were not
sent for evaluation in some cases until they became so ill they could
not care for themselves. Some of these inmates were placed in the
infirmary with other inmates until their diagnosis with TB. On other
occasions, drug susceptibility testing was not reported until after an
inmate's death, which means that appropriate patient management was not
initiated.
As a result of this outbreak, a retrospective epidemiological
investigation was conducted to examine the potential extent and spread
of MDR-TB throughout the New York State prison system during the years
1990-1991 (Ex. 7-137). This investigation revealed that 69 cases of TB
were diagnosed in 1990 and another 102 were diagnosed in 1991,
resulting in a combined incidence of 156.2 cases/100,000 inmate years
for 1990 and 1991 combined. Of the cases, 39 were identified as being
MDR-TB, 31 of which were shown to be epidemiologically linked. Thirty-
three of the individuals with MDR-TB never received any treatment for
MDR-TB, 3 were diagnosed at death, and 23 died before drug
susceptibility results were known. These inmates were also discovered
to be highly mobile. The 39 inmates lived in 23 different prisons while
they were potentially infectious. Twenty transfers were documented for
12 inmates with potentially infectious MDR-TB (9 shortly before
diagnosis, one after diagnosis with TB but before diagnosis with MDR-
TB, and 2 after a diagnosis of MDR-TB).
Several factors were identified as contributing to the spread of
MDR-TB throughout the New York prison system: delays in identifying and
isolating inmates, frequent transfers without appropriate medical
evaluation, lapses in treatment, and delays in diagnosis and
susceptibility testing.
A similar investigation in a California state correctional
institution identified three active cases of TB (two inmates and one
employee) during September and October 1991 (Ex. 6-5). As a result, an
investigation was commenced to determine whether transmission of TB was
ongoing in the institution. Eighteen inmates with active TB were
identified. TB in 10 of these inmates was recognized for the first time
while they were in the institution during 1991, resulting in an annual
incidence of TB of 184 per 100,000, a rate greater than 10 times that
for the state (17.4 per 100,000). Two of the 10 inmates had negative
tuberculin skin tests prior to their entry into the institution. Three
of the cases were determined to have been infectious during 1991.
A review of skin test data revealed that for the 2944 inmates for
whom skin test results were available, 324 tested positive for the
first time while in the prison system. Of these, 106 were tuberculin
negative before their entry into the prison system, 96 of which
occurred in the previous two years.
The employee identified as having active TB had worked as a
counselor on the prison's HIV ward, where he recalled exposure to one
of the 3 infectious inmates. This employee could recall no known
exposures outside the prison. Similarly, two other prison employees had
documented skin test conversions while working at the prison. Neither
recalled exposures outside the prison; one reported exposure to an
inmate with possible TB.
No information was provided in this report as to whether any
isolation precautions were implemented at this facility. However, the
investigators concluded that their findings suggested the likelihood
that transmission of TB had occurred in the prison. Their conclusion
was based on the fact that a substantial number of skin test
conversions were documented among the inmates and that at least two
inmates with active TB became infected while at the prison.
The transmission of TB was also reported in another California
prison among prison infirmary physicians and nurses and correctional
officers (Ex. 6-6). In this investigation, an inmate with active MDR-TB
spent 6 months during 1990-1991 in the infirmary. The infirmary had no
isolation rooms and inmates' cells were found to be under positive
pressure. Employees occasionally recalled wearing surgical masks when
entering the rooms of TB patients.
An analysis of available skin testing data revealed that of the 21
infirmary health care providers, only 10 had been
[[Page 54185]]
tested twice during the period from 1987 to 1990. Of these 10, two were
newly positive, one of whom had recently converted in 1991 and had
spent 5 months in the preceding year providing health care to the
source case in this investigation. Another health care provider and a
correctional officer who worked in the infirmary also were identified
as having newly converted while at the prison. There was no yearly skin
test screening, and thus their conversions could have occurred at any
time between 1987 and 1991. However, 13 other inmates were diagnosed
with pulmonary TB during that same period. An additional correctional
officer who did not work in the infirmary also was found to have newly
converted. His reported exposure occurred at a community hospital where
he was assigned to an inmate with infectious TB. The officer was not
provided with any respiratory protection. The lack of isolation
precautions and the lack of appropriate respiratory protection suggest
transmission of TB from infectious inmates in the infirmary to the
prison staff, either as a result of exposure to the source case or
other inmates with pulmonary TB who were also treated in the prison
infirmary. Because of the lack of contact tracing or routine annual
screening of inmates or staff, the full extent of transmission from the
source case or other TB cases could not be determined.
Thus, similar to the evidence for the hospital setting, the
evidence on correctional facilities shows that the failure to promptly
identify individuals with infectious TB and provide appropriate
infection control measures can result in the exposure and subsequent
infection of employees with TB. These employees include the
correctional facility infirmary staff, guards on duty at the facility,
and guards assigned to escort inmates during transport to other
facilities (e.g., outside health care facilities and other correctional
facilities).
Homeless Shelters
Tuberculosis has also been recognized as a health hazard among
homeless persons. The growth of the homeless population in the United
States since the 1980s and the subsequent increase in the number of
shelters for the homeless, furthers heightens the concern about the
potential for the increased incidence and transmission of TB among the
homeless, especially in crowded living conditions such as homeless
shelters.
A number of factors are present in homeless shelters which increase
the potential for the transmission of TB among the shelter residents
and among the shelter staff. A high prevalence of TB infection and
disease is common among many homeless shelters. This is not surprising,
since the residents of these facilities usually come from lower socio-
economic groups and often have characteristics that place them at high
risk. Screening of selected clinics and shelters for the homeless has
shown that the prevalence of TB infection ranges from 18 to 51% and the
prevalence of clinically active disease ranges from 1.6 to 6.8% (Ex. 6-
15). The CDC estimates this to be 150 to 300 times the nationwide
prevalence rate (Ex. 6-17).
In addition to having a high prevalence of individuals with TB
infection in the shelters, many of the shelter residents possess
characteristics that impair their immunity and thus place them at a
greater risk of developing active disease. For example, homeless
persons generally suffer from poor nutrition, poor overall health
status and poor access to health care. Many also suffer from
alcoholism, drug abuse and psychological stress. Moreover, a
significant portion of homeless shelter residents are infected with the
HIV. In 1988, the Partnership of the Homeless Inc. conducted a survey
of 45 of the nation's largest cities and estimated that there were
between 5,000 and 8,000 homeless persons with AIDS in New York City and
approximately 20,000 nationwide (Ex. 7-55). Due to these factors,
homeless shelter residents are at increased risk of developing active
disease. Thus, there is the increased likelihood that these individuals
will be infectious as a result of active disease and thereby present a
source of exposure for other homeless persons and for shelter
employees.
In addition to having factors which increase their risk of
developing active TB disease, homeless persons also are a very
transient population. Because they are transient, homeless persons are
more likely to discontinue or to erratically adhere to the prescribed
TB therapy. Inadequately adhering to TB therapy can result in relapses
to an infectious state of the disease or the development of MDR-TB.
Both outcomes result in periods of infectiousness, during which they
present a source of exposure to other residents and staff. In addition,
environmental factors at homeless shelters, such as crowded living
conditions and poor ventilation, facilitate the transmission of TB.
Outbreaks of TB among homeless shelter residents have been
reported. For example, during 1990, 17 individuals with active
pulmonary TB were identified among residents of homeless shelters in
three Ohio cities: Cincinnati, Columbus, and Toledo (Ex. 7-51). In
Cincinnati, 11 individuals with active TB were identified in a shelter
for homeless adults. The index case was a man who had resided at the
shelter and later died from respiratory failure. He was not diagnosed
with TB until his autopsy. Of these 11 individuals, of which the index
case was one, 7 were determined to be infectious. There was no
indication as to whether any infection control measures were in place
in the shelter. DNA analysis of 10 individual M. tuberculosis isolates
showed identical patterns. The similarity among these DNA patterns
suggested that transmission of the TB occurred in the shelter.
While the primary focus of this investigation was on the active
cases reported among the residents in this Cincinnati shelter, the risk
of transmission identified in this shelter also would apply to the
shelter staff. Possible transmission of TB infection from the
infectious individuals to the shelter staff might have been identified
through tuberculin skin test conversions. However, no tuberculin skin
test information for the staff was reported in this investigation.
Tuberculin skin testing results were reported in the investigation
of a Columbus, Ohio shelter. In this investigation, a resident of a
Columbus homeless shelter was identified with infectious pulmonary TB
at the local hospital in March of 1990. The patient also had resided in
a shelter in Toledo. As a result, a city-wide TB screening was
initiated from April to May 1990 among the residents and staff of the
city's men's shelters. Tuberculin skin tests were conducted on 363
shelter residents and 123 shelter employees. Among 81 skin-tested
residents of the shelter in which the index case had resided, 32 (40%)
were positive compared to 47 (22%) of 210 skin-tested residents of
other shelters in Columbus who had positive skin test reactions.
Similarly, among 27 employees of the shelter where the index case
resided, 7 (26%) had positive skin test reactions compared to 9 (11%)
of 85 employees in other men's shelters. These skin test results
suggest an increased risk of transmission of TB among residents and
employees of the homeless shelter where the index case resided.
However, due to the lack of baseline skin test information among these
residents and employees it is not possible to determine when their
conversion to positive status occurred and whether this index case was
their source of exposure. These results, however, do indicate a high
prevalence of TB infection among homeless residents
[[Page 54186]]
(e.g., 40% and 22%). Many of these individuals are likely to have an
increased risk of developing active TB and, as a result, they may
present a source of exposure to residents and staff.
The transmission of TB has also been observed among residents and
staff of several Boston homeless shelters (Exs. 7-75 and 6-25). From
February 1984 through March 1985, 26 cases of TB were confirmed among
homeless residents of three large shelters in Boston. Nineteen of the
26 cases occurred in 1984, thus giving an incidence of approximately
317 per 100,000, 6 times the homeless case rate of 50 per 100,000
reported for 1983 and nearly 16 times the 1984 case rate of 19 per
100,000 for the rest of Boston (Ex. 6-25).
Of the 26 cases of TB reported, 15 had MDR-TB. Phage typing of
isolates from 13 of the individuals with drug-resistant TB showed
identical phage types, thus suggesting a common source of exposure. As
a result of this outbreak, a screening program was implemented in
November 1984 over a four-night period. Of 362 people who received skin
tests, 187 returned for reading, 42 (22%) were found to be positive and
3 were recent converters. Screening also was reported for the shelter
staff at the three homeless facilities. At the largest of the three
shelters, 17 of 85 (20%) staff members had skin test conversions. In
the other two shelters, 3 of 15 (20%) and 3 of 18 (16%) staff members
had skin test conversions.
Whereas MDR-TB was primarily involved in the outbreak in Boston, an
outbreak of drug-susceptible TB was reported in a homeless shelter in
Seattle, Washington (Ex. 7-73). From December 1986 to January 1987,
seven cases of TB from homeless residents were reported to the Seattle
Public Health Department. The report of 7 individuals with active TB in
one month prompted an investigation, including: (1) A mass screening to
detect undiagnosed cases, (2) phage typing of isolates from shelter
clients to detect epidemiologically linked cases, and (3) a case-
control study to investigate possible risk factors for the acquisition
of TB.
A review of the case registries revealed that 9 individuals with
active TB had been reported from the homeless shelter for the preceding
year and four cases in the year previous to that. As a result of the
mass screening in late January 1987, an additional 6 individuals with
active TB were detected. Phage typing of 15 isolates from the shelter-
associated cases revealed that 6 individuals with active TB diagnosed
around the time of the outbreak were of the same phage type, suggesting
that there was a predominant chain of infection, i.e., a single source
of infection. However, there also were other phage types, suggesting
several sources of infection. Therefore, the investigators suggested
that there was probably a mixture of primary and reactivated cases.
In addition to the similarity of phage types among TB cases,
tuberculin skin testing results suggested the ongoing transmission of
TB in the shelter. For example, 10 shelter clients who were previously
tuberculin negative in May 1985 were re-tested in January 1987 and 3
(30%) had converted. In addition, 43 clients who were negative in
January 1987 were re-tested in June 1987 or February 1988 and 10 (23%)
had converted. Factors identified as contributing to the outbreak were
the increased number of men with undiagnosed infectious pulmonary TB,
the close proximity of beds in the shelter, and a closed ventilation
system that provided extensive recirculation of unfiltered air.
As a result of the outbreak, a control plan was implemented. This
plan included repetitive mass screening, repetitive skin testing,
directly observed therapy, preventive therapy and modification of the
ventilation system to incorporate UV light disinfection in the
ventilation duct work. After the control plan was in place, five
additional individuals with active TB were observed over a 2-year
follow-up period.
While the primary focus in this study was on clients of the shelter
rather than the shelter staff, the risk factors present in the shelter
before implementation of the control plan would have also increased the
likelihood for transmission of TB to shelter employees from infectious
clients.
Thus, similar to correctional facilities, homeless shelters have a
number of risk factors that facilitate and promote the transmission of
TB (e.g., high incidence of infected residents with an increased
likelihood of developing active disease, crowded living conditions and
poor ventilation). Also, similar to correctional facilities, the
evidence in homeless shelters shows that the failure to promptly
identify homeless residents with infectious TB and the lack of
appropriate TB control measures (e.g., lack of isolation precautions or
prompt transfer to facilities with adequate isolation precautions)
resulted in the transmission of TB to shelter employees.
Long-Term Care Facilities for the Elderly
Long-term care facilities for the elderly also represent a high-
risk population for the transmission of TB. TB disease in persons over
the age of 65 constitutes a large proportion of TB in the United
States. Many of these individuals were infected in the past, before the
introduction of anti-TB drugs and TB control programs when the
prevalence of TB disease was much greater among the general population,
and have harbored latent infection over their lifetimes. However, with
advancing age, these individuals' immune function starts to decline,
placing them at increased risk of developing active TB disease. In
addition, they may have underlying disease or overall poor health
status. Moreover, residents are often clustered together and group
activities are often encouraged. TB case rates are higher for this age
group than for any other. For example, the CDC reports that in 1987,
the 6,150 cases of TB disease reported for persons 65 years
of age accounted for 27% of the U.S. TB morbidity although this group
only represented 12% of the U.S. population (Ex. 6-14).
Because of the higher prevalence of TB cases among this age group,
employees of facilities that provide long-term care for the elderly are
at increased risk for the transmission of TB. More elderly persons live
in nursing homes than in any other type of residential institution. The
CDC's National Center for Health Statistics reports that elderly
persons represent 88% of the nation's approximately 1.7 million nursing
home residents. As noted by the CDC, the concentration of such high-
risk individuals in long-term care facilities creates a high-risk
situation for the transmission of TB (Ex. 6-14).
In addition to having a higher prevalence of active TB, the
recognition of TB in elderly individuals may be difficult or delayed
because of the atypical radiographic appearance that TB may have in
elderly persons (Exs. 7-59, 7-81, 7-82, and 7-83). In this situation,
individuals with active TB may go undiagnosed, providing a source of
exposure to residents and staff.
While the increased incidence of TB cases among the elderly in
long-term care facilities may be a result of the activation of latent
TB infections, the transmission of TB infection to residents and staff
from infectious cases in the facilities has been observed and reported
in the scientific literature.
For example, Stead et al. (1985) examined the reactivity to the
tuberculin skin test among nursing home residents in Arkansas (Ex. 7-
59). This study involved a cross-sectional survey in which tuberculin
skin tests were given to all current nursing home
[[Page 54187]]
residents. In addition, all newly-admitted nursing home residents were
skin tested. For the three year period evaluated, 25,637 residents of
the 223 nursing homes in Arkansas were tested.
Of 12,196 residents who were tested within one month of entry, only
12 percent were tuberculin positive, including those for whom a booster
effect was detected. However, among the 13,441 residents for whom the
first test was delayed for more than a month, 20.8% were positive. In
addition, the results of retesting 9,937 persons who were tuberculin
negative showed an annual conversion rate of approximately 5% in
nursing homes in which an infectious TB case had been recognized in the
last three years. In nursing homes with no recognized cases, the
authors reported an annual conversion rate of approximately 3.5%. The
authors concluded that their data supported the contention that
tuberculosis may be a rather common nosocomial infection in nursing
homes and that new infections with tuberculosis is an important risk
for nursing home residents and staff.
Brennen et al. (Ex. 5-12) described an outbreak of TB that occurred
in a chronic care Veteran's Administration Medical Center in
Pittsburgh. This investigation was initiated as a result of two skin
test conversions identified through the employee testing program. One
converter was a nurse working on ward 1B (a locked ward for
neuropsychiatric patients) and the other was a physician working in an
adjacent ward, 1U, who also had significant exposure to ward 1B. The
source of infection in this investigation was traced to two patients
who had resided on ward 1B and who had either a delayed or undiagnosed
case of TB. The contact investigation revealed 8 additional conversions
among patients, 4 in ward 1B and 4 in wards 2B and 4B (units on the
floor above 1B).
Because the source cases were initially unidentified, no isolation
precautions were taken. Smoke tracer studies revealed that air
discharged from the window air conditioning unit of one of the source
patients discharged directly into the courtyard. Air from this
courtyard was the air intake source for window air conditioning units
in the converters' room on ward 2B and thus was one of the possible
sources of exposure.
In addition to the contact investigation on ward 1B and the
adjacent units, hospital-wide skin testing results were evaluated. Of
395 employees tested, 110 (28%) were positive. The prevalence in the
surrounding community was estimated to be 8.8%. Of those employees
initially negative, 38 (12%) converted to positive status. Included
among these were employees in nursing (18), medical (3), dental (1),
maintenance/engineering (3), supply (1), dietary (9), and clerical (2)
services.
Occupational transmission of TB was also reported in a nursing home
in Oklahoma (Ex. 6-28). In August 1978, a 68 year old female residing
in the east wing of the home was diagnosed with pulmonary TB. She was
subsequently hospitalized. However, by that time she had already had
frequent contact with other residents in the east wing. As a result, a
contact investigation, in which all residents of the home were given
skin tests, was initiated.
The investigation revealed that the reaction rate for residents in
the east wing (34/48, 71%) was significantly higher than the reaction
rates of residents living in the north and front wings (30/87, 34%). No
baseline skin test information was presented for the residents to
determine the level of conversion. However, it was noted that half of
the nursing home residents were former residents of a state institution
for the developmentally disabled. A 1970 tuberculin skin test survey of
that institution had shown a low rate of positive reactions.
In addition to the nursing home residents, nursing home employees
were also skin tested. Of the 91 employees tested, 61 (67%) were
negative and 30 (33%) were positive. Similar to results observed among
the residents, positive reaction rates were higher for employees who
had ever worked in the east wing (50%) than for those who had never
worked in the east wing (23%). Retesting of the employees 3 months
later revealed 3 conversions. These results suggested that there may
have been occupational transmission of TB in this facility.
Occupational transmission has also been observed in a retrospective
study of residents and employees who lived or worked in an Arkansas
nursing home between 1972 and 1981 (Ex. 7-83). In this retrospective
study, investigators reviewed the skin testing and medical chart data
collected over a 10-year period at an Arkansas nursing home. Among the
nursing home residents who were admitted between 1972 and 1982, 32 of
226 residents (17%) who were initially tuberculin negative upon
admittance became infected while in the home, based on conversion to
positive after at least two previous negative tests. Twenty-four (63%)
of these conversions were infected in 1975, following exposure to one
infectious resident. This resident, who had negative skin tests on
three previous occasions during his stay in the home, was not diagnosed
with TB until after he was hospitalized because of fever, loss of
weight and productive cough. The remaining 37% converted in the absence
of a known infectious case. Thus, the authors suggested that nosocomial
infections are likely to result from persons unsuspected of having TB.
Skin testing was also reviewed for employees of the nursing home.
Questionnaires were completed by 108 full-time employees. Eleven of 68
employees with follow-up skin tests converted to positive skin status
during the study period. Ten of the 11 (91%) converters reported that
they had been in the nursing home in 1975, the same year in which many
of the residents were also found to have converted from a single
infectious case. In addition, employees working at least 10 years in
the home had a higher percentage of conversions (9 of 22, 40%) than
employees working less than 10 years (2 of 46, 4.4%). Based on the
results of this study, the authors concluded that, in addition to
occurrence of TB cases from the reactivation of latent infections among
the elderly, TB can also be transmitted from one resident to another
resident or staff. Consequently, TB must be considered as a potential
nosocomial infection in nursing homes.
Thus, long-term care facilities for the elderly represent a high-
risk situation for the transmission of TB. These types of facilities
possess a number of characteristics that increase the likelihood that
active disease may be present among the facility residents and may go
undetected. Similar to other high-risk settings, the evidence shows
that the primary factors in the transmission of TB among residents and
staff have been the failure to promptly identify residents with
infectious TB and initiate and adequately implement appropriate
exposure control measures.
Drug Treatment Centers
Another occupational setting that has been identified as a high-
risk environment for the transmission of TB is drug treatment centers.
Similar to other high-risk sites, drug treatment centers have a higher
prevalence of TB infection than the general population. For example, in
1989 the CDC funded 25 state and city health departments to support
tuberculin testing and administration of preventive therapy in
conjunction with HIV counseling and testing. In this project, 28,586
clients from 114 drug treatment centers were given tuberculin skin
tests. Of those, 2,645 (9.7%) were positive (Ex. 6-8). When persons
with previously
[[Page 54188]]
documented positive tests were included, 4167 (13.3%) were positive.
There is also evidence to suggest that drug dependence is a risk
factor for TB disease. For example, Reichman et al. (Ex. 7-85)
evaluated the prevalence of TB disease among different drug-dependent
populations in New York: (1) An in-hospital population, (2) a
population in a local drug treatment center, and (3) a city-wide
population in methadone clinics. For the in-hospital population of
1,283 patients discharged with drug dependence, 48 (3.74%) had active
disease, for a prevalence rate of 3,740 per 100,000. In comparison, the
TB prevalence rate for the total inpatient population was 584 per
100,000 and for New York City as a whole was 86.7 per 100,000.
Screening of clients at a local drug treatment center in Harlem
revealed a TB prevalence of 3750 per 100,000 in the drug-dependent
population. Similarly, in the New York methadone program, the city-wide
TB prevalence was 1,372 per 100,000. The authors also reported that
although estimates of TB infection rates for both drug-dependent and
non-drug dependent people were similar, the prevalence of TB disease
among the drug-dependent was higher, thus suggesting that drug
dependency may be a risk factor for disease.
Clients of drug treatment centers not only have a high prevalence
of TB infection, a majority of them are intravenous drug users. Of the
estimated 645,000 clients discharged each year from drug treatment
centers, approximately 265,000 are intravenous drug users who either
have or are at risk for HIV infection. In the Northeastern U.S., HIV
seroprevalence rates of up to 49% have been reported (Ex. 6-8). These
individuals are at increased risk of developing active TB disease.
To determine the risk of active TB associated with HIV infection,
Selwyn et al. (Ex. 5-6) prospectively studied 520 intravenous drug
users enrolled in a methadone maintenance program. In this study, 217
HIV seropositive and 303 seronegative intravenous drug users, who had
complete medical records documenting their history of TB and skin test
status, were followed from June 1985 to January 1988. On admission to
the methadone program, and at yearly intervals, all patients were given
tuberculin skin tests.
Forty-nine (23%) of the seropositive patients and 62 (20%) of the
seronegative patients had positive reactions to the skin test before
entry into the study. Among the patients who initially had negative
skin tests, 15 of 131 (11%) seropositive patients and 62 of 303 (13%)
seronegative patients converted to positive tuberculin status. While
the prevalence and incidence rates of TB infection were similar for the
two groups of patients, seropositive patients showed a higher incidence
of developing active disease. Active TB developed in 8 of the
seropositive subjects with TB infection (4%), whereas none of the
seronegative patients with TB infection developed active TB during the
study period.
Among individuals who are infected with HIV or who have AIDS, TB
disease may be difficult to diagnosis because of the atypical
radiographic appearance that TB may present in these individuals. In
these individuals, TB may go undiagnosed and present an unsuspected
source of exposure. Clients of drug treatment centers also may be more
likely to discontinue or inadequately adhere to TB therapy regimens in
instances where they develop active disease. As in other instances,
this increases the likelihood of relapse to active disease or possibly
the development of MDR-TB, both of which result in additional or even
prolonged periods of infectiousness during which other clients or staff
can be exposed.
There is evidence showing the transmission of TB in drug treatment
facilities among both the clients and the staff. In a CDC case study
(Ex. 5-6), a Michigan man who was living in a residential substance
abuse treatment facility and was undergoing therapy for a previously
diagnosed case of TB disease, was discovered by the local health
department to have MDR-TB. As a result, a contact investigation was
initiated at the drug treatment facility in which he resided.
Of the 160 clients and staff who were identified as potential
contacts, 146 were tested and given tuberculin skin tests in November.
No health screening program had been in place at the facility. The
following March repeat skin tests were given. Of the 70 persons who
were initially tuberculin negative and were still present in the
facility, 15 (21%) had converted to positive status (14 clients and 1
staff member). The investigators noted that the number of converters
may have been underestimated for two reasons. Many of the clients were
at risk for HIV infection and thus may have been anergic and not
responded to the tuberculin skin tests. In addition, nearly half of the
clients who were initially negative were not available for repeat skin
testing.
Several factors may have contributed to the observed conversions in
this facility. For example, no health screening program was in place.
Therefore, individuals with TB would go unidentified. In addition, the
clients were housed in a building with crowded dormitories for
sleeping. The only ventilation in this building was provided by opening
windows and doors. Thus, environmental conditions were ideal for the
transmission of TB.
Consequently, the high-risk characteristics of clients who frequent
these centers (e.g., high prevalence of infection and factors
increasing the likelihood of developing active disease) and
environmental characteristics of the center (e.g., crowding and poor
ventilation), lead to drug treatment centers being considered a high-
risk setting for the transmission of TB. The available evidence shows
that the failure to promptly identify clients with infectious TB and to
initiate and properly implement exposure control methods (e.g., proper
ventilation) resulted in the infection of clients and staff at these
facilities.
Conclusion
The available evidence clearly demonstrates that the transmission
of TB represents an occupational hazard in work settings where
employees can reasonably be anticipated to have contact with
individuals with infectious TB or air that may reasonably be
anticipated to contain aerosolized M. tuberculosis as a part of their
job duties. Epidemiological studies, case reports, and outbreak
investigations have shown that in various work settings where there has
been an increased likelihood of encountering individuals with active TB
or where high-hazard procedures are performed, employees have become
infected with TB and in some cases developed active disease. While some
infections were a result of more direct and more prolonged exposures,
other infections resulted from non-direct and brief or intermittent
exposures. Because of the variability in the infectiousness of
individuals with active TB, one exposure may be sufficient to initiate
infection.
Several factors, common to many of these work settings, were
identified as contributing to the transmission of TB: (1) Failure or
delayed recognition of individuals with active TB within the facility,
and (2) failure to initiate or adequately implement appropriate
infection control measures (e.g., performance of high-hazard procedures
under uncontrolled conditions, lack of negative pressure ventilation,
recirculation of unfiltered air, and lack of appropriate respiratory
protection). Thus, in work settings where employees can reasonably be
anticipated to have contact with individuals with infectious
[[Page 54189]]
TB or air that may contain aerosolized M. tuberculosis and where
appropriate infection control programs are not in place, employees are
at increased risk of becoming infected with TB.
Infection with TB is a material impairment of the worker's health.
Even though not all infections progress to active disease, infection
marks a significant change in an individual's health status. Once
infected, the individual is infected for his or her entire life and
carries a lifetime risk of developing active disease, a risk they would
not have had they not been infected. In addition, many individuals with
infection undergo preventive therapy to stop the progression of
infection to active disease. Preventive therapy consists of very toxic
drugs that can cause serious adverse health effects and, in some cases,
may be fatal.
Although treatable, active disease is also a serious adverse health
effect. Some TB cases, even though cured, may result in long-term
damage to the organ that is infected. Individuals with active disease
may need to be hospitalized while they are infectious and they must
take toxic drugs to stop the progressive destruction of the infected
tissue. These drugs, as noted above, are toxic and may have serious
side effects. Moreover, even with advancements in treating TB,
individuals still die from TB disease. This problem is compounded by
the emergence of multidrug-resistant strains of TB. In these cases, due
to the inability to find adequate drug regimens which can treat the
disease, individuals remain infectious longer, allowing the disease to
progress further and cause more progressive destruction of the infected
tissue. This increases the likelihood of long-term damage and death.
V. Preliminary Risk Assessment for Occupational Exposure to
Tuberculosis
Introduction
The United States Supreme Court, in the ``benzene'' decision
(Industrial Union Department, AFL-CIO v. American Petroleum Institute,
448 U.S. 607 (1980)), has stated the OSH Act requires that, prior to
the issuance of a new standard, a determination must be made, based on
substantial evidence in the record considered as a whole, that there is
a significant health risk under existing conditions and that issuance
of a new standard will significantly reduce or eliminate that risk. The
Court stated that
``before he can promulgate any permanent health or safety standard,
the Secretary is required to make a threshold finding that a place
of employment is unsafe in the sense that significant risks are
present and can be eliminated or lessened by a change in practices''
(448 U.S. 642).
The Court in the Cotton Dust case (American Textile Manufacturers
Institute v. Donovan, 452 U.S. 490 (1981)), rejected the use of cost-
benefit analysis in setting OSHA health standards. However, the Court
reaffirmed its previous position in the ``benzene'' case that a risk
assessment is not only appropriate, but also required to identify
significant health risk in workers and to determine if a proposed
standard will achieve a reduction in that risk. Although the Court did
not require OSHA to perform a quantitative risk assessment in every
case, the Court implied, and OSHA as a matter of policy agrees, that
assessments should be put into quantitative terms to the extent
possible. The following paragraphs present an overall description of
OSHA's preliminary quantitative risk assessment for occupational
exposure to tuberculosis (TB).
An earlier version of this risk assessment was reviewed by a group
of four experts in the fields of TB epidemiology and mathematical
modeling. The reviewers were George Comstock, MD, MPH, DPH, Alumni
Centennial Professor of Epidemiology, The Johns Hopkins University;
Neil Graham MBBS, MD, MPH, Associate Professor of Epidemiology, The
Johns Hopkins University; Bahjat Qaqish, MD, PhD, Assistant Professor
of Biostatistics, University of North Carolina; and Patricia M. Simone,
MD, Chief, Program Services Branch, Division of Tuberculosis
Elimination, CDC. The reader is referred to the peer review report in
the docket for additional details (Ex. 7-911). The revised version of
OSHA's risk assessment, as published in this proposed rule, includes
OSHA's response to the reviewers' comments as well as updated risk
estimates based on recent purified protein derivative (PPD) skin
testing data made available to the Agency since the peer review was
performed and is generally supported by the reviewers or is consistent
with reviewers' comments. (Note: PPD skin test and tuberculin skin test
(TST) are synonymous terms.)
The CDC estimates that, once infected with M. tuberculosis, an
untreated individual has a 10% lifetime probability of developing
active TB and that approximately half of those cases will develop
within the first or second year after infection occurs. Individuals
with active TB represent a pool from which the disease may spread.
Based on data from the CDC, OSHA estimates that every index case (i.e.,
a person with infectious TB) results in at least 2 other infections
(Ex. 7-269). For some percentage of active cases, a more severe
clinical course can develop which can be attributed to various factors
such as the presence of MDR-TB, an allergic response to treatment, or
the synergistic effects of other health conditions an individual might
have. Further, OSHA estimates that for 7.78% of active TB cases, TB is
expected to be the cause of death. Section 6(b)(5) of the OSH Act
states that,
The Secretary, in promulgating standards dealing with toxic
materials or harmful physical agents under this subsection, shall
set the standard which most adequately assures, to the extent
feasible, on the basis of the best available evidence, that no
employee will suffer material impairment of health or functional
capacity even if such employee has regular exposure to the hazard
dealt with by such standard for the period of his working life.
For this rulemaking, OSHA defines TB infection as a ``material
impairment of health'', for several reasons. First, once infected with
TB, an individual has a 10% lifetime likelihood of developing active
disease and approximately 1% likelihood of developing more serious
complications leading to death. Second, allergic reaction and hepatic
toxicity due to chemoprophylaxis with isoniazid, which is one of the
drugs used in the recommended course of preventive treatment, pose a
serious threat to a large number of workers. Third, defining infection
with M. tuberculosis as material impairment of health is consistent
with OSHA's position in the Bloodborne Pathogens standard and is
supported by CDC and several stakeholders who participated in the pre-
proposal meetings, as well as Dr. Neil Graham, one of the peer
reviewers of this risk assessment. In his comments to OSHA, Dr. Graham
stated,
The focus of OSHA on risk of TB infection rather than TB disease
is appropriate. TB infection is a potentially adverse event,
particularly if exposure is from a MDR-TB patient, or if the health-
care or institutional worker is HIV seropositive. In addition, a
skin test conversion will in most cases mandate use of
chemoprophylaxis for >6 months which is at least inconvenient and at
worst may involve adverse drug reactions. (Ex. 7-271)
The approach taken in this risk assessment is similar to the
approach OSHA took in its risk assessment for the Bloodborne Pathogens
standard. As with bloodborne pathogens, the health response (i.e.,
infection) associated with exposure to the pathogenic agent does not
depend on a cumulative level of exposure; instead, it is a function of
intensity and frequency of each
[[Page 54190]]
exposure incident. However, unlike hepatitis B, where the likelihood of
infection once an exposure incident occurs is known with some degree of
certainty, the likelihood of becoming infected with TB after an
exposure incident is not as well characterized. With TB, the likelihood
of infection depends on the potency of an exposure incident and the
susceptibility of the exposed individual (which is a function of the
person's natural resistance to TB and his or her health status).
Further, the potency of a given exposure incident is highly dependent
on several factors, such as the concentration of droplet nuclei in the
air, the duration of exposure, and the virulence of the pathogen (e.g.,
pulmonary and laryngeal TB are considered more infectious than other
types).
The Agency has sufficient data to quantify the risk associated with
occupational exposure to TB among health care workers in hospitals on a
state-by-state basis. In addition to hospital employee data, OSHA has
obtained data on selected health care employee groups from the TB
Control Office of the Washington State Health Department. These groups
include workers employed in long-term health care, home health care,
and home care. Small entities are encouraged to comment and submit any
data or studies on TB infection rates relevant to their business.
Because it is exposure to aerosolized M. tuberculosis that places
workers at risk of infection, and not some factor unique to the health
care profession, the Agency concluded that the experience of these
groups of health care workers is representative of that of the other
``high-risk'' workers covered by this proposal. This means that the
risk estimates calculated for these groups of workers are appropriate
to use as the basis for describing the potential range of risks for
workers in other work settings where workers can be expected to come
into close and frequent contact with individuals with infectious TB (or
with other sources of aerosolized M. tuberculosis) as an integral part
of their job duties. As discussed in section IV (Health Effects),
epidemiological studies, case reports, and outbreak investigations have
shown that workers in various work settings, including but not limited
to hospitals, have become infected with tuberculosis as a result of
occupational exposure to aerosolized M. tuberculosis when appropriate
infection control programs for tuberculosis were not in place.
In this preliminary risk assessment, OSHA presents risk estimates
for TB infections, cases of active disease, and TB-related deaths
(i.e., where TB is considered the cause or a major contributing cause
of death) for workers with occupational exposure to tuberculosis.
A number of epidemiological studies demonstrate an increased risk
of TB infection among health care workers in hospitals and other work
settings. A brief review of a selection of these studies is presented
below, followed by OSHA's estimates of excess risk due to occupational
exposure. Finally, OSHA presents a qualitative assessment of the risk
of TB infection caused by occupational exposure to tuberculosis in
correctional facilities, homeless shelters, drug treatment centers,
medical laboratories, and other high-risk work groups.
Review of the Epidemiology of TB Infection in Exposed Workers
There are several studies in the published scientific literature
demonstrating the occupational transmission of infectious TB. Reports
of TB outbreaks and epidemiologic surveillance studies have shown that
health care and certain other workers are, as a result of their job
duties, at significantly higher risk of becoming infected than the
average person.
OSHA conducted a thorough search of the published literature and
reviewed all studies addressing occupational exposure to tuberculosis
and TB infection in hospitals and other work settings. All published
studies show positive results (i.e., workers exposed to infectious
individuals have a high likelihood of becoming infected with TB).
Because there are so many studies, OSHA selected a representative
subset of the more recent studies conducted in the U.S. to include in
this section. These studies were chosen because they show occupational
exposure in various work settings, under various working conditions,
and under various scientific study designs.
OSHA's summary of the studies is presented in Table V-1(a) and
Table V-1(b). These studies represent a wide range of occupational
settings in hospitals, ranging from TB and HIV wards in high prevalence
areas, such as New York City and Miami, to hospitals with no known TB
patients located in low prevalence areas such as the state of
Washington. The studies include prospective studies of entire hospitals
or groups of hospitals, retrospective surveys of well-controlled
clinical environments, such as an HIV ward in a hospital, and case
studies of single-source infection (i.e., outbreak investigations).
Table V-1(a).--Outbreak Investigations of TB infection
----------------------------------------------------------------------------------------------------------------
Risk of TB in health
Authors/year Setting/source care workers Contributing factors
----------------------------------------------------------------------------------------------------------------
Catanzaro (1982)...................... Hospital intensive care 14/45 (31%) PPD Poor ventilation. No
unit/San Diego/1 index conversions, 10/13 report on respirator
case--7-day hospital (77%) PPD conversions use.
stay. among health care
workers present at
bronchoscopy.
Kantor et al. (1988).................. VA hospital in Chicago 9/56 (16%) PPD No mechanical
autopsy room/1 index conversions among ventilation on
case undiagnosed until exposed workers vs. 3/ medical ward (autopsy
histology exam of 333 (1%) conversions room): no isolation.
autopsy tissue. among unexposed Autopsy room had 11
(RR=17.8) 3 workers air changes/hour and
developed active TB. no air recirculation.
Beck-Sague (1992)..................... Jackson Memorial 13/39 (33%) PPD Some rooms had
Hospital in Miami MDR- conversions on HIV positive pressure.
TB in HIV/patients on ward and clinic. Inadequate triage of
HIV ward and clinic patients with
during 1989-91. suspected TB. Delay
in use of isolation.
Early discharge from
isolation.
----------------------------------------------------------------------------------------------------------------
[[Page 54191]]
Table V-1(b).--Surveillance Studies of TB Infection in Exposed Health Care Workers
----------------------------------------------------------------------------------------------------------------
Risk of TB in
Authors/year Setting/source Study Population health care Comments
period workers
----------------------------------------------------------------------------------------------------------------
Price et al. (1987)......... 19 Eastern North 1980-84 All Hospital 1.80% annual PPD
Carolina workers. conversion rate.
hospitals.
29 Central North ......... ................ 0.70% annual PPD
Carolina conversion rate.
hospitals.
8 Western North ......... ................ 0.61% annual PPD
Carolina conversion rate.
hospitals.
Aitken et al. (1987)........ 64 hospitals in 1982-84 All Hospital 0.1% PPD Strict adherence
Washington State. workers. conversion rate/ to CDC
in 3 years. guidelines.
Malasky et al. (1990)....... 14 urban (\1\) Physicians in 11% PPD
hospitals in U.S. training in conversion/3
pulmonary years among
medicine and pulmonary
infectious fellows, 2.4%
disease. PPD conversions/
3 years among
infectious
disease fellows.
Dooley et al. (1992)........ Hospital in 1989-90 Hospital workers Prevalence Isolation rooms
Puerto Rico TB (n=908). study: 54/109 did not have
in HIV-infected (50%) nurses negative
patients. exposed to TB pressure.
patients had Recirculated
positive PPDs air was not
35/188 (19%) filtered.
clerical
workers with no
exposure to TB
had positive
PPDs (p<0.001). niosh.......................="" jackson="" memorial="" 1989-92="" hospital="" workers="" 60%="" annual="" ppd="" incomplete="" hospital,="" miami.="" in="" selected="" conversion="" isolation="" wards="" (n="607)." among="" 263="" facilities.="" exposed="" improper="" workers,="" 0.6%="" application="" of="" annual="" ppd="" isolation="" conversion="" procedures.="" among="" 344="" unexposed="" workers.="" cocchiarella="" et="" al.="" (1996)..="" cook="" county="" 1991="" graduating="" 18.8%="" 3-year="" ppd="" residents="" were="" hospital,="" physicians="" with="" conversion="" rate="" offered="" limited="" chicago.="" at="" least="" 1="" year="" for="" house="" staff="" respiratory="" of="" clinical="" in="" internal="" protection="" work="" at="" cch="" medicine="" vs.="" during="" (n="128)." 2.2%="" ppd="" exposures.="" no="" conversion="" rate="" protocol="" for="" house="" staff="" available="" for="" in="" other="" early="" specialties.="" identification="" of="" suspect="" tb="" cases.="" ppd="" testing="" program="" incomplete.="" inadequate="" isolation="" facilities.="" ----------------------------------------------------------------------------------------------------------------="" \1\="" mid="" 1980's="" (3="" years).="" outbreak="" investigations="" describe="" occupational="" exposure="" to="" tuberculosis="" from="" single="" index="" patients="" or="" a="" well-defined="" group="" of="" patients.="" such="" investigations="" are="" more="" likely="" to="" demonstrate="" an="" upper="" limit="" of="" occupational="" risk="" in="" different="" settings,="" usually="" under="" conditions="" of="" suboptimal="" environmental="" and="" infection="" controls.="" although="" outbreak="" investigations="" demonstrate="" the="" existence="" of="" occupational="" risk="" under="" certain="" conditions="" and="" the="" importance="" of="" the="" early="" identification="" of="" suspect="" tb="" patients="" quite="" well,="" these="" studies="" do="" not="" provide="" information="" conducive="" to="" risk="" assessment="" estimations.="" limitations="" of="" outbreak="" investigations="" include="" the="" frequent="" absence="" of="" baseline="" ppd="" test="" results,="" the="" difficulty="" of="" extrapolating="" the="" results="" to="" non-="" outbreak="" conditions="" of="" tb="" exposure,="" and,="" often,="" small="" sample="" sizes.="" table="" v-1(a)="" lists="" some="" of="" the="" published="" outbreak="" investigations="" and="" shows="" the="" risks="" posed="" to="" health="" care="" workers="" by="" such="" outbreaks,="" as="" well="" as="" the="" failures="" in="" control="" programs="" contributing="" to="" these="" episodes.="" prospective="" and/or="" retrospective="" surveillance="" studies="" are="" used="" to="" estimate="" conversion="" rates="" from="" negative="" to="" positive="" in="" ppd="" skin="" testing="" programs.="" these="" conversion="" rates="" can="" be="" used="" to="" estimate="" the="" excess="" incidence="" of="" tb="" infection.="" surveillance="" studies="" among="" health="" care="" workers="" lend="" themselves="" to="" a="" more="" systematic="" evaluation="" of="" the="" risk="" of="" tb="" infection="" than="" outbreak="" investigations,="" for="" several="" reasons.="" first,="" these="" studies="" better="" reflect="" the="" risk="" of="" tb="" experienced="" by="" workers="" under="" routine="" conditions="" of="" exposure.="" second,="" these="" studies="" are="" usually="" based="" on="" a="" larger="" group="" of="" workers="" and="" therefore="" yield="" more="" precise="" and="" accurate="" estimates="" of="" the="" actual="" risk="" of="" infection.="" however,="" the="" extent="" to="" which="" results="" from="" surveillance="" studies="" can="" be="" generalized="" depends="" on="" a="" careful="" evaluation="" of="" the="" study="" population.="" some="" studies="" report="" skin="" test="" conversion="" rates="" for="" all="" workers="" in="" the="" hospital(s)="" under="" study.="" such="" studies="" often="" include="" large="" groups="" of="" employees="" with="" little="" or="" no="" exposure="" to="" tb.="" results="" from="" such="" studies="" may="" reflect="" an="" overall="" estimate="" of="" risk="" in="" that="" environment,="" but="" may="" underestimate="" the="" occupational="" risk="" of="" those="" with="" frequent="" exposure.="" other="" surveillance="" studies="" report="" ppd="" conversion="" rates="" of="" more="" narrowly-defined="" groups="" of="" workers,="" usually="" those="" working="" in="" ``high-="" risk''="" areas="" within="" a="" hospital="" such="" as="" the="" hiv="" or="" tb="" wards.="" some="" of="" these="" studies="" have="" internal="" control="" groups="" (i.e.,="" they="" compare="" ppd="" conversion="" rates="" between="" a="" group="" of="" workers="" with="" extensive="" exposure="" to="" tb="" and="" a="" group="" of="" workers="" with="" minimal="" or="" no="" exposure="" to="" tb),="" thus="" making="" it="" possible="" to="" more="" precisely="" quantify="" the="" magnitude="" of="" excess="" risk="" due="" to="" occupational="" exposure.="" however,="" these="" studies="" are="" also="" limited="" in="" their="" usefulness="" for="" risk="" assessment="" purposes.="" they="" usually="" have="" small="" sample="" sizes,="" making="" it="" more="" difficult="" to="" observe="" statistically="" significant="" differences.="" more="" [[page="" 54192]]="" importantly,="" internal="" control="" groups="" may="" overestimate="" background="" risk,="" and="" thus="" underestimate="" excess="" occupational="" risk,="" unless="" painstaking="" efforts="" are="" made="" to="" eliminate="" from="" the="" control="" group="" those="" individuals="" with="" the="" potential="" for="" occupational="" exposure,="" a="" difficult="" task="" in="" some="" hospital="" environments.="" table="" v-1(b)="" contains="" a="" selected="" list="" of="" published="" surveillance="" studies.="" in="" reviewing="" table="" v-1(a)="" and="" table="" v-1(b),="" the="" reader="" should="" bear="" in="" mind="" that="" these="" tables="" are="" not="" intended="" to="" present="" an="" exhaustive="" list="" of="" epidemiologic="" studies="" with="" tb="" conversion="" rates="" in="" occupational="" settings.="" instead,="" these="" tables="" present="" brief="" summaries="" of="" some="" of="" the="" epidemiologic="" evidence="" of="" occupational="" tb="" transmission="" found="" in="" the="" published="" literature;="" they="" are="" intended="" to="" convey="" the="" seriousness="" of="" the="" risk="" posed="" to="" health="" care="" workers="" and="" to="" illustrate="" how="" failures="" in="" control="" programs="" contribute="" to="" this="" risk.="" upon="" reviewing="" these="" studies,="" a="" consistent="" pattern="" emerges:="" these="" work="" settings="" are="" associated="" with="" a="" high="" likelihood="" for="" occupational="" exposure="" to="" tuberculosis,="" and="" high="" rates="" of="" tb="" infection="" are="" being="" observed="" among="" health="" care="" workers.="" quantitative="" assessment="" of="" risk="" data="" availability="" usually="" dictates="" the="" direction="" and="" analytical="" approach="" osha's="" risk="" assessment="" can="" take.="" for="" this="" rulemaking,="" three="" health="" endpoints="" will="" be="" used:="" (1)="" tb="" infection,="" which="" is="" ``material="" impairment="" of="" health''="" for="" this="" proposed="" standard;="" (2)="" active="" disease="" following="" infection;="" and,="" (3)="" risk="" of="" death="" from="" active="" tb.="" in="" order="" to="" account="" for="" regional="" variability="" in="" tb="" prevalence="" and="" therefore="" to="" account="" for="" expected="" variability="" in="" the="" risk="" of="" tb="" infection="" in="" different="" areas,="" the="" agency="" chose="" to="" develop="" occupational="" risk="" estimates="" on="" a="" state-by-state="" basis.="" this="" approach="" was="" criticized="" by="" dr.="" neil="" graham="" as="" being="" too="" broad="" and="" ''*="" *="" *="" insufficient="" in="" light="" of="" the="" tremendous="" variability="" *="" *="" *="" that="" can="" occur="" within="" a="" state.''="" (ex.="" 7-911).="" the="" agency="" recognizes="" that="" risk="" estimates="" on="" a="" county-by-="" county="" basis="" would="" be="" preferable;="" however,="" the="" unavailability="" of="" comprehensive="" county="" data="" has="" prevented="" the="" agency="" from="" conducting="" such="" analysis.="" the="" annual="" excess="" risk="" of="" tb="" infection="" due="" to="" occupational="" exposure="" is="" defined="" as="" a="" multiplicative="" function="" of="" the="" background="" rate="" of="" infection="" and="" is="" expressed="" as:="" p="">o * Rb
where:
p is the annual excess risk due to occupational exposure,
Rb is the background rate of TB infection, and
ERRo is a multiplicative factor denoting the excess relative
risk due to occupational exposure (ERRo).
Estimates of ERRo are derived from surveillance studies
of workers with occupational exposure to TB. ERRo is defined
as the relative difference between the overall exposed worker risk and
the background (population) risk and is calculated as the difference
between overall worker and background risk divided by the background
risk.
The annual excess risk due to occupational exposure is defined as a
function of the background risk because of data limitations. If data on
overall worker risk were available for each state, then the excess risk
due to occupational exposure would simply be the difference between
overall worker risk and background risk. Instead, the annual excess
risk due to occupational exposure (i.e., p) is estimated using a
multiplicative model because data on overall worker risk (i.e.,
Rw) were available only for the states of Washington, and
North Carolina and for Jackson Memorial Hospital located in Miami,
Florida. Therefore, the annual excess risk due to occupational exposure
in state i (pi) is expressed as:
[GRAPHIC] [TIFF OMITTED] TP17OC97.000
where:
Rwj is the overall worker risk estimated from surveillance
studies (study j),
Rbj is the study control group risk (i.e., study background
risk), and
Rbi is the background rate for state i.
When i=j (i.e., Washington State or North Carolina), the excess
risk due to occupational exposure, is expressed as the straight
difference between overall worker risk and background risk.
OSHA calculated estimates of ERRo based on three
occupational studies: the Washington State study, the North Carolina
study, and the Jackson Memorial Hospital study (Exs. 7-263, 7-7, 7-
108). These estimates were expressed as percent change above each
study's background. The derivation of these estimates is described in
section 2.
In order to estimate an overall range of occupational risk of TB
infection, taking into account regional differences in TB prevalence in
the U.S., OSHA: (1) Estimated background TB infection rates by state
(Rbi), and (2) applied estimates of ERRo, derived
from the occupational studies, to the state background rates to
calculate estimates of excess risk due to occupational exposure by
state.
OSHA used a multiplicative function of each state's background
infection rate to estimate excess risk of TB infection because the
probability of occupational infection can be viewed as a function of
the number of contacts and frequency of contacts with infectious
individuals. Thus, estimates of expected relative increase in risk
above background due to occupational exposure are calculated for the
three available studies and these relative increases (i.e.
ERRo) are multiplied by background rates for each state to
derive estimates of excess occupational risk by state. These state
estimates are then used to derive a national estimate of occupational
risk.
The CDC compiles and publishes national statistics on the incidence
of active TB in the U.S. by state based on reported cases. OSHA relied
on these data to estimate TB infection background rates through the use
of a mathematical model because information on TB infection is not
being collected nationwide by CDC. A more detailed discussion on the
methodology and derivation of background risk estimates by state is
found in section 3, and discussion on the estimation of occupational
risk estimates by state is found in section 4 of this risk assessment.
Because section 6(b)(5) of the OSH Act requires OSHA to assess
lifetime risks, OSHA has converted the annual excess risk due to
occupational exposure into an excess lifetime risk based on a 45-year
working lifetime. The formula used to calculate lifetime occupational
risk estimates of the probability of at least one occurrence of TB
infection due to occupational exposure in 45 years is expressed as { 1-
(1-p)45 }, where p is the annual excess risk due to
occupational exposure. Two assumptions are critical in defining
lifetime risk: (1) the exposure period is 45 years, and (2) the annual
excess risk remains constant. The implication of the second assumption
is that the worker's exposure profile and working conditions, which may
affect the level and intensity of exposure, and the virulence of the
pathogen, remain unchanged throughout a working lifetime. The merit of
this assumption was questioned by Dr. Graham, because, as he states ``*
* * patient contact may vary greatly throughout a career for many HCWs
[health care workers].'' and `` * * * physicians (and nurses) often do
not have extensive patient contact until [their] mid-twenties, while
other workers increasingly retire early.'' Dr. Graham recommends that
OSHA's risk assessment be adjusted to account for variable exposure
levels and variable working lifetimes. Although accounting
[[Page 54193]]
for variable exposure levels could result in more precise risk
estimates, the unavailability of comprehensive information on lifetime
TB exposure scenarios by occupational group prevented the Agency from
developing a more complex risk model.
OSHA has customarily assumed a 45 year working lifetime in setting
health standards. The Agency believes that this assumption is
reasonable and consistent with the Act. The Act requires the Secretary
to set a standard for toxic substances that would assure ``no employee
* * * suffer material impairment of health or functional capacity even
if such employee has regular exposures to the hazard for the period of
his working lifetime.'' 29 U.S.C. Sec. 655(b)(5) (emphasis added). The
U.S. Court of Appeals for the District of Columbia upheld the use of a
45-year lifetime in the asbestos standard against an assertion by the
Asbestos Information Association that the average duration of
employment was five years. Building and Construction Trades Department,
AFL-CIO v. Brock, 838 F.2d 1258, 1264, 1265 (D.C. Cir. 1988). The Court
said that OSHA's assumption ``appears to conform to the intent of
Congress'' as the standard must protect even the rare employee who
would have 45 years of exposure. Id. at 1264. In addition, while
working lifetimes will vary, risk is significant for some who work as
little as one year and, at any rate, individual and population risks
are likely to remain the same so long as employees who leave one job
are replaced by others, and those who change jobs remain within a
covered sector. Nevertheless, the Agency solicits information regarding
the likelihood of exposure to active TB in the workplace and duration
of employment in various occupational groups. Lifetime risk estimates
of TB infection by state are described in section 4.
Lifetime risk estimates of developing active TB are calculated from
lifetime risk estimates of TB infection assuming that, once infected,
there is a 10% likelihood of progressing to active TB. These estimates
are discussed in section 4. Further, the number of deaths caused by TB
is calculated from the lifetime estimates of active TB using OSHA's
estimate of TB case fatality rate, also discussed in section 4.
1. Definitions
For the purpose of estimating incidence rates, TB infection rate is
defined as the annual probability of an individual converting from
negative to positive in the tuberculin skin test. Annual occupational
risk is defined as the annual excess risk of becoming infected with TB
due to occupational exposure, and is estimated as a function of the
background risk. Lifetime occupational risk is defined as the excess
probability of becoming infected with TB due to exposure in the
workplace, at least once, in the course of a 45-year working lifetime
and is estimated as { 1-(1-p)45 } where p is the annual
occupational risk of TB infection.
2. Data Sources for Estimating Occupational Risk
The quantitative data needed to develop an overall national
estimate of risk for TB infection due to occupational exposure are not
available. The CDC does not publish occupational data associated with
TB infection incidence and active TB on a nationwide basis. There has
been some effort to include occupational information on the TB
reporting forms, but only a limited number of states are currently
using the new forms that capture occupational information in a
systematic way.
However, there are a number of sources that permit the risk in
occupational settings to be reasonably estimated and, with the aid of
mathematical models, to develop estimates of excess relative
occupational risk (ERRo), which can then be multiplied by
the state-specific background rates to yield estimates of excess
occupational risk. OSHA has identified three data sources that are
suitable for assessing the excess risk of TB infection in health care
workers with occupational exposure. These include: (1) A 1994 survey of
tuberculin skin testing in all health care facilities in Washington
State; (2) A state-wide survey of hospitals in North Carolina,
conducted in 1984-1985, which addressed TB skin testing practices, TB
infection prevalence, and TB infection incidence among hospital
employees in that state; and (3) the employee tuberculin skin test
conversion database from Jackson Memorial Hospital in Miami, Florida.
In addition to these hospital employee data, the Agency has obtained
data on selected other work groups from the state of Washington. These
groups include workers employed in long-term health care, home health
care, and home care.
On the issue of data availability for this risk assessment, Dr.
Graham agrees with OSHA that there are no comprehensive data available
with respect to occupational risk of TB infection in health care and
other institutions in the U.S. Instead of relying on two state specific
studies, Dr. Graham recommends, though with serious reservations, the
use of a review study by Menzies et al. (Ex. 7-130). Dr. Graham admits
that the ``validity of the estimates in these reports [reviewed in the
Menzies et al. study] must be open to serious question * * *'' for the
following reasons, which were pointed out by Dr. Graham: several of the
studies reviewed are very old and not relevant to TB risk in the 1990s;
four studies use tine tests and self-reports of skin test results,
which are not useful for estimation of risk of TB infection; the
studies were not consistent in the inclusion of high and low risk
workers; two-step testing was not done; and the participation rates
were extremely low or unreported in many of the studies included in
this review.
OSHA has chosen not to rely on the Menzies et al. review study,
because, in addition to Dr. Graham's reservations (which the Agency
shares), OSHA is also concerned about the inclusion in the Menzies et
al. review article of studies conducted outside the U.S. Factors known
to affect the epidemiology of TB, such as environmental conditions,
socio-economic status, and work practices, are expected to differ
greatly from one country to another, and are not controlled for in the
statistical analyses of these studies. For all of these reasons, the
Agency has chosen to rely solely on U.S. studies for its quantitative
risk estimations.
Estimates of excess risk due to occupational exposure are expressed
as the percent increase above background based on relative risk
estimates derived from occupational studies. Internal control groups
provided estimates of background risk for the Washington state and
Jackson Memorial data sets. In the absence of a suitable internal
control group, the estimated annual state-wide TB infection rate, as
calculated in Section 3, was used as the background rate in the North
Carolina study.
(a) Washington State Data: Initially, OSHA relied on a three-year
prospective study, conducted between 1982 and 1984 in the state of
Washington, to derive an estimate of excess risk for TB infection as a
result of occupational exposure (Ex. 7-42). OSHA received several
objections to the use of this study. The study used hospitals with no
known TB cases as ``controls'' based on the assumption that in those
hospitals the risk of TB infection to employees may be the same as for
the general population. Dr. Qaqish noted that this assumption is highly
questionable and that the use of such controls is not appropriate. Dr.
Graham and Dr. Qaqish pointed out that the published results did not
include conversions identified through contact investigations, which
[[Page 54194]]
means that the conversion rate reported in that study was likely to be
an underestimate of the true risk. In addition, the commenters noted
that the study was designed to estimate the effectiveness of the TB
screening program and may have produced skin testing results biased
toward the null; the study is relatively old; and, the study was
conducted prior to the AIDS epidemic and therefore the results may not
be relevant to the occupational risk at present because the
relationship between HIV and TB is not reflected in this study.
In an effort to respond to reviewers' comments, the Agency chose to
update the analysis by relying on a data set of tuberculin skin testing
results from a survey of the state's tuberculin skin testing program in
1994. This survey is conducted by the TB Control Office in the
Washington State Health Department and it covers all hospitals in the
state, as well as long-term care, home health care, and home care
facilities. OSHA was given access to the database for the 1994 survey
as well as data on conversions identified through contact
investigations for the same year (Ex. 7-263). Table V-2 summarizes the
results of the 1994 survey. Of the 335 health care establishments in
the state of Washington, 273 responded to the survey, for an overall
response rate of 81.5%. Of those, 76 were hospitals, 142 were long-term
care, 47 were home health care, and 8 were home care facilities.
Hospitals had the highest survey response rate (85%) and home health
care had the lowest (77%). Every employee at risk for TB infection
(i.e., who was known to be tuberculin skin test negative at the start
of the study period) in the participating hospitals and long-term care
facilities was given a tuberculin skin test, including administrators,
housekeepers, business office staff, and all part-time employees.
Testing in home health care facilities was generally confined to those
nursing staff who had direct client contact. Employees in home care are
those who provide services to patients in home health care and include
food handlers, cleaning aides, personal care-givers, and some social
workers.
Table V-2--Washington State 1994 Survey Results
----------------------------------------------------------------------------------------------------------------
Annual
Type of facility Number of a establishments Number of Number of rate of TB
skin tests conversions conversion
----------------------------------------------------------------------------------------------------------------
Hospital................................ 76 (85%) 39,290 50 1.27/1,000
Long-term Care.......................... 142 (81%) 11,332 111 9.80/1,000
Home Health Care........................ 47 (77%) 2,172 11 5.06/1,000
Home Care............................... 8 (80%) 537 1 1.86/1,000
-----------------------------------------------------------------------
Total............................... 273 (81.5%) 53,331 173 3.24/1,000
----------------------------------------------------------------------------------------------------------------
a Numbers in parentheses are study response rates for each group.
The overall rate of skin test conversion for workers in the health
care system in Washington State in 1994 was 3.24 per 1,000 employees
tested. This is greater than a 4-fold increase from the estimated
state-wide background rate of 0.69 per 1,000 at risk, as calculated in
section 3. The annual rate of TB conversion ranged from 1.27 per 1,000
tested for hospital employees to 9.80 per 1,000 tested for long-term
care employees.
The annual rate of 9.8 per 1,000 for long-term care employees
probably reflects the high potential for exposure to undiagnosed active
TB in those facilities. As a rule, long-term facilities in Washington
State do not have AFB isolation rooms. Therefore, residents with no
obvious TB symptoms but who might be infectious spend most of their
time in open spaces exposing other residents and workers to infectious
droplet nuclei. However, once a resident has been identified as a
suspect TB patient, that person is transferred to a hospital until
medically determined to be non-infectious.
Also, since employees who were 35 years of age or younger were not
given a two-step test at hiring, and a high percentage of employees are
foreign born and therefore most likely to have been vaccinated during
childhood with the BCG vaccine, some of the conversions observed might
be late boosting because of BCG. However, an almost two-fold increase
in risk for long-term care workers even as compared to the significant
excess risk among home health care workers clearly indicates that the
risk of TB infection for workers in long-term care is high and not
likely to be fully explained by late boosting. Beginning in 1995, two-
step testing has been done on all new hires in Washington State. Thus,
tuberculin skin testing data for 1995 are not expected to be influenced
by possible late boosting; OSHA will place the 1995 data in the
rulemaking record as they become available.
Hospital workers had the lowest overall rate of conversion (overall
rate of 1.27 per 1,000). This, in part, can be attributed to the
existence of extensive TB control measures in that environment in
Washington State. Compliance with the CDC Guidelines and OSHA's TB
Compliance Directive is quite high in Washington State because: (a)
There is a strong emphasis on early identification of suspect TB
patients; (b) there is a strong emphasis on employee training and
regular tuberculin skin testing (although on a less-frequent basis than
recommended in the Guidelines: All employees are tested at hire and
annually thereafter); (c) the use of respirators is expected when
entering an isolation room; and (d) all isolation rooms are under
negative pressure, have UV lights, and exhaust to the outside. In
addition, conversion data in hospitals are more likely to represent
true TB infections than in the other health care settings, because
hospitals are more likely to re-test converters in an effort to
eliminate false-positive cases.
A more thorough analysis of the hospital data is presented in table
V-3. Because the Washington State survey was not designed to compare
exposed persons with matched controls who have had no exposure, several
alternative definitions of an internal control (unexposed) group were
used in analyzing this data set. Three different analyses, shown in
table V-3, produced estimates of annual occupational infection rates
ranging from 0.4 to 0.6 per 1,000 above control (i.e., ranging from a
47% to an 84% increase above control). In order to minimize the
likelihood of contaminating the control group with persons having
significant occupational exposure, OSHA defined the control group as
workers in hospitals located in zero-TB counties and with no known TB
patients. This analysis is summarized in table V-3 as Definition 1. If
potential for occupational exposure is defined as
[[Page 54195]]
either working in a hospital in a county that has active TB or in a
hospital that has had TB patients, then the annual risk due to
occupational exposure is 47% above background. The excess annual risk
due to occupational exposure appears to be approximately 60% above
background, if workers in hospitals with a transfer-out policy for TB
patients are considered to be the control group, shown as Definition 2
in table V-3. A 60% increase above background is not statistically
significantly different from a 47% increase and therefore these two
``control'' groups can be viewed as producing ``statistically''
equivalent results. However, the Agency believes that Definition 1 is
more appropriate, though the risk estimates are higher if the control
group is defined based on Definition 2, because there is a higher
likelihood of potential for exposure to a patient with undiagnosed TB
under Definition 2 conditions. Comparisons of all hospital TST data to
the state-wide estimate of TB infection rate resulted in an estimate of
the annual excess occupational risk of approximately 84% above
background, shown in table V-3 as Definition 3. Estimates of the annual
and lifetime occupational risk of TB infection for the average health
care worker in hospitals by state, extrapolated from this study and
using Definition 1 as the control group, are presented and summarized
in section 4.
Table V-3--Washington State Data Hospital PPD Skin Testing Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
Number of Number of Average Overall Relative risk
Definition of exposed and control groups Sample size skin tests conversions conversion conversion ------------------
given observed rate 1 a rate 2 b Rate 1 Rate 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
Definition 1
Control: Hospitals in zero-TB counties and with no-known TB
patients......................................................... 16 1,142 1 0.477 0.8756 ....... ........
Exposed: Hospitals in counties reporting TB or having TB patients. 60 38,148 49 1.523 1.28447 3.19 1.47
Definition 2
Control: Hospitals that transfer out TB patients.................. 35 3,645 3 0.498 0.823 ....... ........
Exposed: Hospitals with isolation rooms........................... 41 35,645 47 1.989 1.3185 3.99 1.602
Definition 3
Control: State-wide estimates of annual risk of infection......... ........... ........... ........... c0.69 c0.69 ....... ........
Exposed: All PPD testing data..................................... 76 39,290 50 1.302 1.27 1.89 1.84
--------------------------------------------------------------------------------------------------------------------------------------------------------
aRate 1 is estimated as the arithmetic average of hospital specific conversion rates.
bRate 2 is estimated as the ratio of the sum of all conversions reported divided by the total number of skin tests given within each group.
cSource: Table V-3(b), state-wide rate of infection.
Annual rates of excess risk due to occupational exposure were
estimated for long-term care, home health care, and home care and are
presented in Section 4. The same control group used in the hospital
data analysis, Definition 1 (i.e., 0.876/1,000 workers at risk) was
used to estimate the background risk among workers in long-term care,
health care, and home care facilities and settings. Using 0.876 as the
background infection rate for workers in these settings (a) provided a
level of consistency among the Washington data analyses, and (b)
resulted in a lower estimate of occupational risk for the non-hospital
health care workplaces than would have resulted had the state-wide
background risk estimate (i.e., 0.67/1,000 see Section 3) been used.
When industry-specific risk data are used, there is approximately a 10-
fold increase in annual risk for workers in long-term care, a 5-fold
increase in annual risk for workers in home health care, and a 1-fold
increase in annual risk for workers in home care (see Section 4).
Estimates of the range of annual and lifetime occupational risk for
the average health care worker in long-term care, home health care, and
home care by state, extrapolated from the Washington State study, are
presented in Section 4.
(b) North Carolina Study: A state-wide survey of all hospitals in
North Carolina (NC) was conducted in 1984-1985 (Ex. 7-7). The survey's
questionnaire was designed to address three main areas of concern
affecting hospital employees: (1) Tuberculin skin testing practices;
(2) TB infection prevalence; and (3) TB infection incidence. The
incidence of new infections among hospital personnel was assessed over
a five-year period by reviewing tuberculin skin test conversion data
during calendar years 1980 through 1984 and was calculated as the
number of TB skin test conversions divided by the number of skin tests
administered. (Since most employees were only given annual testing, the
number of tests administered is a very close estimate of the total
number of people tested within a year and thus can be used as the
denominator in estimating infection incidence.) Only 56 out of 167
hospitals reported information on TB conversion rates (34% response
rate). The authors estimated a state-wide TB infection rate of 11.9 per
1,000 per year for hospital employees in 1984 and a five-year mean
annual infection rate of 11.4 per 1,000, with a range of 0-89 per 1000
employees at risk for TB infection. An analysis of the data by region
(i.e., eastern, central, western) showed that the eastern region had
consistently higher rates (with an average infection rate of 18.0 per
1,000) followed by the central region (7.0 per 1,000) and the western
region (6.1 per 1000). Results of this study are shown in table V-4.
[[Page 54196]]
Table V-4--Skin Test Conversion Rates a North Carolina Hospital Personnel b
----------------------------------------------------------------------------------------------------------------
Year
Region -----------------------------------------------------------------------------------
1980 1981 1992 1993 1984 5-year mean
----------------------------------------------------------------------------------------------------------------
Eastern..................... 19.3
(7) 30.8
(10) 17.7
(11) 11.2
(12) 15.7
(18) 18.0
(19)
Central..................... 3.0
(6) 3.7
(8) 7.2
(13) 6.6
(23) 10.0
(25) 7.0
(29)
Western..................... 1.9
(2) 13.5
(4) 5.3
(4) 4.1
(4) 7.2
(8) 6.1
(8)
----------------------------------------------------------------------------------------------------------------
a Conversion rates are expressed as number of conversions per 1,000 workers tested.
b In parentheses is the number of hospitals included in the study.
Use of this study's overall results for risk estimates was
criticized by the peer reviewers because of design flaws in the study
(e.g., high non-response rate, inconsistent skin testing practices, and
limited two-step testing) and, most importantly, the presence of
atypical mycobacteria (contributing to false positive results) in the
eastern part of the state. Based on further input from Dr. Comstock,
the Agency chose to rely on the study results from the western region
only, because they are considered to be more representative of the
``true'' risk of infection and are expected to be less confounded by
cross-reactions to atypical mycobacteria. Further, the Agency chose to
rely on the conversion rate estimated for 1984 because it was the most
recent data reported in the study. Therefore, the western region
conversion rate of 7.2 per 1,000, estimated based on responses to the
survey from eight hospitals in 1984, was used as an overall worker
conversion rate. Further, the 1984 rate was adjusted by the percent
decrease of active TB between 1984 and 1994 in North Carolina so that
the final worker conversion rate for 1994 based on the western region
rates reported in this study was estimated to be 5.98 (7.2 * 532/641 =
5.98) per 1,000 employees at risk for TB infection.
The North Carolina study did not have an internal control group to
use as the basis for estimating excess risk due to occupational
exposure because the conversion rates presented in this study were
based on TST results for the entire hospital employee population. In
the absence of an internal control group, the Agency used the estimated
state-wide background rate of 1.20 per 1,000 as the background rate of
infection for the western region in North Carolina (see Section 3) to
estimate excess risk due to occupational exposure.1 Based on
this study, annual occupational risk is approximately four times
greater than background [(5.98-1.2)/1.2 = 3.98]. Estimates of the
annual and lifetime occupational risk of TB infection based on this
study by state are presented in Section 4.
---------------------------------------------------------------------------
\1\ Using the state-wide estimate of population risk as the
background estimate of risk for this study most likely results in an
underestimate of the true excess risk due to occupational exposure,
because the true background estimate of risk for the western region
in North Carolina is expected to be less than the state-wide
estimate, which is influenced by the large number of infections
found in the eastern region of that state.
---------------------------------------------------------------------------
(c) Jackson Memorial Hospital Study: Jackson Memorial Hospital
(JMH) is a 1500-bed general facility located in Miami, Florida,
employing more than 8,000 employees. It is considered one of the
busiest hospitals in the U.S. It is the primary public hospital for
Dade County and the main teaching hospital for the University of Miami
School of Medicine. JMH treats most of the TB and HIV cases in Dade
County and, consequently, there is a higher likelihood of occupational
exposure to TB in this facility than in the average hospital in the
U.S. From March 1988 to September 1990, an outbreak of multidrug-
resistant TB (MDR-TB) occurred among patients and an increased number
of TST conversions was observed among health care workers on the HIV
ward. This prompted a re-evaluation of the hospital's infection control
practices and the installation of engineering controls to minimize
exposure to TB. As part of the evaluation of the outbreak, NIOSH did a
Health Hazard Evaluation and issued a report (Ex. 7-108). In addition,
NIOSH conducted a retrospective cohort study of JMH to determine
whether the risk of TB infection was significantly greater for health
care workers who work on wards having patients with infectious TB than
those who work on wards without TB patients.
For the data analysis of this study, ``potential for occupational
exposure'' was defined based on whether an employee worked on a ward
that had records of 15 or more positive cultures for pulmonary or
laryngeal TB during 1988-1989. In other words, positive culture was
taken as a surrogate for exposure to infectious TB. The authors
restricted the ``exposed'' group to employees on wards with exposures
to pulmonary or laryngeal TB because they intended to restrict the
study to hospital workers with exposure to patients with the highest
potential for being infectious. There were 37 wards at JMH that had
submitted at least one positive culture during 1988-1989. Seven wards
met the criteria of 15 or more and were therefore included in the
``exposed'' group. These were the medical intensive care unit, five
medical wards, and the emergency room. The ``control'' group was
defined as hospital workers assigned to wards with no TB patients
(i.e., wards with no records of positive cultures during 1988-89). The
``control'' wards were post-partum, labor and delivery, newborn
intensive care unit, newborn intermediate care unit, and well newborn
unit. The results of this analysis are presented in Table V-5.
Table V-5--Skin Test Conversion Rates for Hospital Personnel at Jackson Memorial Hospital a, b
----------------------------------------------------------------------------------------------------------------
95%
Year Exposed Control Relative confidence
group group risk interval
----------------------------------------------------------------------------------------------------------------
1989...................................................... 62.2
(13/209) 6.2
(2/324) 10.1 2.3--44.2
[[Page 54197]]
1990...................................................... 75.5
(16/212) 6.5
(2/309) 11.7 2.7--50.2
1991...................................................... 31.7
(6/189) 3.5
(1/282) 9.0 1.1--73.8
----------------------------------------------------------------------------------------------------------------
a Rates are expressed as number of conversions per 1,000 workers tested.
b Source: Ex. 7-108
Table V-5 shows a substantially elevated risk for those workers
with potential exposure to patients with infectious TB. The relative
risk ranges from 9 to 11.7 between 1989 and 1991 and is statistically
significant for all of those years. This suggests that the excess risk
due to occupational exposure is approximately 8-fold above background;
this is an overall risk estimate that reflects the occupational risk of
TB infection for JMH employees with patient contact, because this
analysis included everyone tested in the ``exposed'' and ``control''
group, regardless of his or her specific job duties or length of
patient contact.
An analysis of various occupational groups within this cohort
showed that nurses and ward clerks in the ``exposed'' groups had the
highest conversion rates: 182 and 156 conversions per 1,000 workers
tested, respectively. Other studies have shown that health care workers
who provide direct patient care are at greater risk for infection than
workers who do not provide direct patient care. The high risk seen in
ward clerks was unexpected since these workers are not involved in
direct patient care. However, in the emergency room, the risk for TST
conversion for the ward clerks was almost three times higher than for
the nurses, 222 and 83 per 1,000, respectively. Ward clerks in the
emergency room are responsible for clerical processing of patients
after triage, handling specimens for the laboratory, and gathering
clothing and valuables from admitted patients. During these
interactions, there may have been less strict adherence to infection
control measures, and this could explain the high conversion rate.
OSHA used the results from the 1991 analysis of the data in the JMH
study to estimate occupational risk of TB infection in hospital workers
with a relatively high likelihood of occupational exposure, for the
following reasons: (a) 1991 represents the most recent year for which
conversion data are available prior to the time when TB infection
control measures were fully implemented at JMH; and (b) The higher
conversion rates reported for 1990 and 1989 (75.5 and 62.2 per 1,000
respectively) may be atypical, i.e., they may to some extent reflect
the effect of the outbreak and not the long-term occupational risk.
Based on the results of this study, OSHA estimates that the annual
excess risk of TB infection due to occupational exposure is 7.95 times
greater than background. Estimates of annual and lifetime occupational
risk of TB infection for the average health care worker in hospitals by
state, extrapolated from this study, are presented and summarized in
section 4.
3. Estimation of Background Risk of TB Infection
OSHA's methodology for estimating population (background) TB
infection rates relies on the assumption that TB infection occurring in
an area can be expressed as a numerical function of active TB cases
reported in the same area. If the likelihood of observing any infection
in a population is minimal, then the likelihood of observing active
disease diminishes. Conversely, the presence of active TB implies the
presence of infection, since active disease can only progress from
infection. Therefore, there is a functional relationship linking TB
infections to active disease being observed in a particular area during
a specified time period.
Peer reviewer comments on this assumption varied. Neil Graham
states in his comment ``Although factors such as migration and
distribution of the population may influence this relationship it seems
probable that this assumption is largely correct and justifiable.''
(Ex. 7-271). On the other hand, Dr. Simone expresses concern over this
assumption and states ``It is not necessarily true that a change in
cases now reflects the risk of infection now.'' Dr. Qaqish demonstrates
in his comment that the net effect of assuming a proportional
relationship between the number of active cases and the number of new
infections is to introduce a possible bias into the estimate of
background risk of TB infection, although such a bias could work in
either direction, i.e., toward increasing or decreasing the estimate of
risk. Dr. Qaqish further states that in the absence of more ``relevant
data,'' it is not possible to determine the actual net effect in
magnitude and direction of the bias and ``without obtaining additional
data, it would be impossible for the Agency to improve on the accuracy
of the risk estimates * * * '' OSHA has considered all of the reviewer
comments and is aware of the inherent uncertainty and the potential for
bias associated with the use of this assumption; however, in the
absence of the additional ``relevant'' data to which Dr. Qaqish refers,
the Agency believes this approach to be justifiable.
In defining the model used to estimate the annual infection rates
occurring in a geographical area based on data on active disease cases
reported for the same area, infections progressing to active disease
are assigned to one of three distinct groups: those occurring this
year, last year, and in previous years.
BILLING CODE 4510-26-P
[[Page 54198]]
[GRAPHIC] [TIFF OMITTED] TP17OC97.001
BILLING CODE 4510-26-C
TB cases reported to CDC each year are a combination of new and old
infections that have, for various reasons, progressed to active
disease. Until recently, it was believed that most of the active cases
were the product of old infections. However, with the use of DNA
fingerprinting techniques, researchers have reported that a larger
percentage of active cases may be attributed to new or recent
infections. Small et al. reported, in an article on tracing TB through
DNA fingerprinting, that as many as 30% of the active cases reviewed in
the study may be the result of recent infections (Ex. 7-196).
In this risk assessment, the Agency assumes the lifetime risk that
an infection will progress to active TB to be approximately 10%. This
estimate is supported by CDC and in her comment, Dr. Simone states
that: ``The assumption * * * is generally agreed upon.'' Dr. Comstock
and Dr. Qaqish both questioned the validity and accuracy of CDC's
estimate. Their comments suggest that the true lifetime rate of
progression from infection to active disease for adults may be less
than 10 percent. However, as Dr. Graham points out, the 10% assumption
is a widely accepted ``rule of thumb'' and is also in relative
agreement with data from the unvaccinated control group of the British
Medical Research Council (MRC) vaccination trial in adolescents (Ex. 7-
266).
In the MRC study, 1,338 adolescents' skin tests converted following
TB exposure where the precise date of conversion was known. Of these,
108 (8.1%) individuals developed active TB during follow-up. Of these,
54% developed active TB within one year and 78% within 2 years. This
results in a risk of approximately 4% at one year, 6% at two years, and
an overall risk of 8%. Given that the risk of TB reactivation increases
with age, the lifetime risk is expected to be higher than the 8%
attained in this study and, as Dr. Graham points out, a 10% overall
lifetime risk seems reasonable.
Based on Dr. Graham's recommendation to rely on the progression
rates from the MRC study, OSHA changed the assumption on the
progression parameters from 2.5% (first year), 2.5% (second year), and
5% (remaining lifetime) to 4%, 2% and 4%, respectively. Therefore the
total 10% progression from infection to active disease is partitioned
into 3 groups: progression during the first year after infection (40%
of all infections that eventually progress, for a net probability of
4%), progression during the second year (20% of all infections that
eventually progress, for a net probability of 2%), and progression
during all subsequent years (the remaining 40% of progressing
infections). This last probability (4%) is assumed to be uniformly
distributed across the remaining lifespan.
TB rates vary considerably by geographic area, socio-economic
status, and other factors. In an attempt to account for some of those
factors, to the extent possible, background TB infection rates have
been estimated separately for each state. The derivation of background
infection rates involves several steps for which the process and
formulae are presented below.
Step 1: Background rate of TB infection for state i in year j is
defined as:
Bi(j)=Ii(j)/Xi(j) (1)
where:
Bi(j) is the background TB infection rate for state i in
year j
Ii(j) is an estimate of the number of new infections that
occurred in state i in year j
Xi(j) is the population at risk for TB infection in state i
in year j.
Step 2: Estimation of Ii(j), the number of new TB
infections:
Let:
Ai(j) be the total number of adult TB cases reported to CDC
by state i in year j.
A(j) be the total number of adult TB cases reported to CDC
by all states in year j.
Pi(j) be the estimated prevalence of adult TB infection in
state i during year j.
Ri be the ratio of the number of adult TB cases reported in
1993 to the number of adult cases reported in 1994 in state i.
The number of TB cases reported in 1994 can be expressed as a
function of TB infections expected to have progressed to active
disease, by the following formula:
Ai(1994)=.04*Ii(1994)+.02*Ii(1993)+(.04
/73)*Ii(1992)*prob(alive in 1994)
+(.04/73)*Ii(1991)*prob(alive in 1994)
+....
+....
+(.04/73)*Ii(1919)*prob(alive in 1994)
This can be expressed as:
Ai(1994)=.04*Ii(1994)+.02*Ii(1993)+(.04
/73)* [Ii(j)*prob(alive in 1994)],
where j ranges from 1919 to 1992. The quantity inside the summation
symbol is the sum of all people who were infected with TB between 1919
and 1992 and are still alive in 1994. This summation can be
approximated by the prevalence of TB infection in 1992,
Pi(1992). Therefore, the number of active TB cases reported
in 1994 can be expressed as:
Ai(1994)=.04*Ii(1994)+.02*Ii(1993)+(.04
/73)*Pi(1992) (2)
Further, if we assume that the number of new infections is directly
proportional to the number of active cases, then Ii(1993)
can be expressed as follows:
Ii(1993)=Ii(1994)*(Ai(1993)/
Ai(1994)) (3)
and (2) can be expressed as:
Ai(1994)=[(.02*(Ai(1993)/
Ai(1994))+.04]*Ii(1994)+(.04/
73)*Pi(1992)
Ai(1994)=[(.02*Ri+.04]*Ii(1994)+(.04/
73)*Pi(1992) (4)
then solving for Ii(1994) becomes: 2
\2\ Using the prevalence of TB infection in 1992 (i.e.,
Pi(1992)) to approximate the quantity inside the
summation sign (i.e., everyone infected between 1919 and 1992 and
alive in 1994) slightly overestimates the quantity inside the
summation (i.e., Pi(1992) is slightly larger than the
quantity it approximates.) It includes a small number of people who
were infected with TB and were alive as of 1992 and who were
therefore included in the prevalence figure, but who died before
1994, and, technically, are not included in the summation. This
implies that, in equation (5), a slightly larger number is being
subtracted from Ai(1994) than should be, resulting in an
underestimate of the number of new infections in 1994 and an
underestimate of the occupational risk.
---------------------------------------------------------------------------
[[Page 54199]]
Ii(1994)=[Ai(1994)-.04/73*Pi(1992)]/
---------------------------------------------------------------------------
(.02*Ri+.04) (5)
Step 3: Estimation of Xi(1994):
Xi(1994), the population at risk for TB infection in
state i in 1994, is estimated as follows:
Xi(1994)=Ni-Pi(1993) (6)
Where:
Ni is the adult population for state i as reported by U.S.
Census in 1994.
Pi(1993) is the estimated number of infected adults in state
i in 1993 (i.e., prevalence of TB infection in state i among adults).
To estimate the number of adults currently at risk for TB infection in
each state, the number of already infected adults (i.e., prevalence of
TB infection Pi in 1993) is subtracted from the adult
population in 1994.
Step 4: Estimation of population currently infected as of 1993 by
state, Pi(1993):
The prevalence of TB infection in each state is estimated as a
function of TB infection prevalence in the U.S. in 1993 and the percent
TB case rate for each state.
Pi(1993)=P(1993)*(Ai(1993)/
A(1993)) (7)
Where:
P(1993) is the prevalence of TB infections in the U.S. in
1993 (Ex. 7-66) and
A(1993) is the total number of adult TB cases reported in
1993.
Estimates of TB infection prevalence in the U.S. were developed for
OSHA by Dr. Christopher Murray of the Harvard Center for Population and
Development Studies and are presented in Table V-6 (Ex. 7-267). The
mathematical model used by Dr. Murray to estimate TB infection
prevalence has been designed to capture the transmission dynamics of TB
by modeling transfers between a series of age-stratified compartments
using a system of differential equations. The model adjusts for various
epidemiological factors known to influence the course of active TB,
such as onset of infection (i.e., old vs. new infections) and the
impact of immigration rates and the HIV epidemic. However, it does not
differentiate among gender or race categories. The model has been
successfully validated using actual epidemiological data on active TB
from 1965 to 1994. The estimates of TB prevalence rates presented here
are specific for adults (i.e., older than 18 years of age), which make
them more appropriate for estimating risk of transmission in an
occupational setting.
Table V-6.--National Prevalence of TB Infection in Adults (18+) a b
----------------------------------------------------------------------------------------------------------------
Year Expected Minimum Maximum
----------------------------------------------------------------------------------------------------------------
1992......................................................... 6.87%
(12,978,461) 6.53%
(12,336,150) 7.22%
(13,639,663)
1993......................................................... 6.64%
(12,667,062) 6.31%
(12,037,524) 6.97%
(13,296,599)
1994......................................................... 6.47%
(12,449,445) 6.14%
(11,814,465) 6.79%
(13,065,182)
----------------------------------------------------------------------------------------------------------------
a Numbers in parentheses are population prevalence figures.
b Estimated for OSHA by Christopher Murray MD, PhD, Harvard University, Center for Population and Development
Studies (Ex. 7-267).
To estimate the number of previously infected adults in each state
(Pi), the estimated national TB prevalence figure was
multiplied by the active cases for each state and divided by the total
number of active cases reported [see equation (7)] (i.e., the national
prevalence estimate was apportioned among the states based on each
state's percent contribution to active TB reported for 1993). To
estimate the number of adults at risk of TB infection, (Xi),
the number of already infected adults was subtracted from the adult
population estimate for each state (see equation (6)). The number of
new infections expected to have occurred in 1994 was estimated using
equation (5).
The background rate of TB infection for 1994 was then estimated by
dividing the number of new infections (Ii) by the number of
susceptible adults in each state (Xi) (see equation (1)).
Results on estimated TB background annual infection rates for each
state are presented in Table V-7(a)--Table V-7(c). In Table V-7(a) TB
infection rates are based on an average value of TB infection
prevalence, as estimated by Dr. Murray, in the U.S. (i.e., 12,667,062).
In Table V-7(b), infection rates are based on the minimum value of TB
infection prevalence in the U.S. (i.e., 12,037,524). In Table V-7(c),
infection rates are based on the maximum value of TB infection
prevalence in the U.S. (i.e., 13,296,599). An overall range of
background annual TB infection rates was constructed by combining all
three sets of infection rates and was estimated to be between 0.194 and
3.542 per 1,000 individuals at risk of TB infection, with a weighted
average of 1.46 per 1,000 using state population size as weights.
Table V-7(a).--Estimates of Annual Background TB Infection Rates a
[Referent Year 1994]
Annual
TB cases Population Population Population at Estimate of population
State reported in size a currently risk new infections rate of TB
1994 infected b infection
Ai Ni Pi(1993) Xi Ii Bi
--------------------------------------------------------------------------------------------------------------------------------------------------------
Alabama (01)............................................ 413 3,139 250,083 2,888,917 4,779 1.65
Alaska (02)............................................. 78 414 27,787 386,213 1,182 3.06
Arizona (04)............................................ 233 2,936 118,231 2,817,769 2,858 1.01
Arkansas (05)........................................... 235 1,813 107,334 1,705,666 2,906 1.70
California (06)......................................... 4,291 22,754 2,437,044 20,280,956 47,852 2.36
[[Page 54200]]
Colorado (08)........................................... 90 2,686 52,850 2,633,150 1,045 0.40
Connecticut (09)........................................ 144 2,487 81,182 2,405,818 1,665 0.69
Delaware (10)........................................... 51 531 26,152 504,848 671 1.33
D.C. (11)............................................... 116 451 80,092 370,908 1,162 3.13
Florida (12)............................................ 1,675 10,691 846,687 9,844,314 20,545 2.09
Georgia (13)............................................ 676 5,162 396,646 4,765,354 7,082 1.49
Hawaii (15)............................................. 234 875 132,942 742,058 25,890 3.49
Illinois (17)........................................... 1,021 8,669 622,211 8,046,789 10,994 1.37
Indiana (18)............................................ 201 4,279 129,673 4,149,327 2,083 0.50
Iowa (19)............................................... 62 2,180 31,056 2,068,943 859 0.42
Kansas (20)............................................. 77 1,864 37,049 1,826,951 1,065 0.58
Kentucky (21)........................................... 316 2,857 203,227 2,653,773 3,273 1.23
Louisiana (22).......................................... 412 3,080 185,792 2,894,208 5,582 1.93
Maine (23).............................................. 31 934 14,712 919,289 419 0.46
Maryland (24)........................................... 344 3,743 211,399 3,531,601 3,582 1.01
Massachusetts (25)...................................... 299 4,617 183,067 4,433,933 2,889 0.65
Michigan (26)........................................... 438 6,971 246,269 6,724,731 5,036 0.75
Minnesota (27).......................................... 127 3,326 68,105 3,257,895 1,413 0.43
Mississippi (28)........................................ 262 1,913 141,659 1,771,341 3,120 1.76
Missouri (29)........................................... 241 3,899 128,583 3,770,417 2,922 0.78
Montana (30)............................................ 22 618 11,987 606,013 290 0.48
Nebraska (31)........................................... 22 1,181 12,531 1,168,469 233 0.20
Nevada (32)............................................. 111 1,181 50,670 1,130,330 1,514 1.34
New Hampshire (33)...................................... 17 845 13,076 831,924 182 0.22
New Jersey (34)......................................... 764 5,973 456,579 5,516,421 8,150 1.48
New Mexico (35)......................................... 78 1,156 35,415 1,120,585 944 0.84
New York (36)........................................... 3,414 13,658 2,044,797 11,613,203 34,728 2.99
North Carolina (37)..................................... 532 5,314 298,574 5,015,426 6,000 1.20
North Dakota (38)....................................... 10 466 3,813 426,186 132 0.29
Ohio (39)............................................... 318 8,248 161,274 8,086,726 3,763 0.47
Oklahoma (40)........................................... 231 2,378 101,886 2,276,114 3,064 1.35
Oregon (41)............................................. 146 2,303 78,457 2,224,543 1,793 0.81
Pennsylvania (42)....................................... 583 9,154 379,211 8,774,789 5,886 0.67
Rhode Island (44)....................................... 47 757 31,601 725,399 495 0.68
South Carolina (45)..................................... 362 2,712 205,406 2,506,594 4,273 1.70
South Dakota (46)....................................... 26 513 8,173 504,827 342 0.68
Tennessee (47).......................................... 494 3,878 283,863 3,594,137 5,759 1.60
Texas (48).............................................. 2,276 13,077 1,199,200 11,877,800 27,306 2.30
Utah (49)............................................... 47 1,236 23,973 1,212,027 427 0.35
Vermont (50)............................................ 10 434 2,724 431,276 160 0.37
Virginia (51)........................................... 330 4,949 226,110 4,722,890 3,220 0.68
Washington (53)......................................... 241 3,935 142,729 3,792,251 2,554 0.67
West Virginia (54)...................................... 80 1,393 40,318 1,352,682 919 0.68
Wisconsin (55).......................................... 104 3,735 50,126 3,684,874 1,307 0.35
Wyoming (56)............................................ 12 339 3,814 335,186 188 0.56
--------------------------------------------------------------------------------------------------------------------------------------------------------
a Expressed in thousands.
b Based on 6.64% rate of TB infection prevalence in the U.S. (expected)
Table V-7(b).--Estimates of Annual Background TB Infection Rates
[Referent Year 1994 a]
Annual
TB cases Population Population Population at Estimate of population
State reported in size a currently risk new infections rate of TB
1994 infected b infection
Ai Ni Pi(1993) Xi Ii Bi
--------------------------------------------------------------------------------------------------------------------------------------------------------
Alabama (01)............................................ 413 3,139 237,654 2,901,346 4,871 1.68
Alaska (02)............................................. 78 414 26,406 387,594 1,196 3.09
Arizona (04)............................................ 233 2,936 112,355 2,823,645 2,913 1.03
Arkansas (05)........................................... 235 1,813 102,000 1,711,000 2,967 1.73
California (06)......................................... 4,291 22,754 2,350,136 20,403,864 48,956 2.40
Colorado (08)........................................... 90 2,686 50,223 2,635,777 1,066 0.40
Connecticut (09)........................................ 144 2,487 77,147 2,409,853 1,700 0.71
Delaware (10)........................................... 51 531 24,853 506,147 681 1.34
D.C. (11)............................................... 116 451 76,111 374,889 1,192 3.18
[[Page 54201]]
Florida (12)............................................ 1,675 10,691 804,607 9,886,393 20,944 2.12
Georgia (13)............................................ 676 5,162 376,933 4,785,067 7,275 1.52
Hawaii (15)............................................. 234 875 126,335 748,665 2,652 3.54
Illinois (17)........................................... 1,021 8,669 591,288 8,077,712 11,260 1.39
Indiana (18)............................................ 201 4,279 123,228 4,155,772 2,136 0.51
Iowa (19)............................................... 62 2,180 29,513 2,070,487 869 0.42
Kansas (20)............................................. 77 1,864 35,208 1,828,792 1,079 0.59
Kentucky (21)........................................... 316 2,857 193,126 2,663,874 3,357 1.26
Louisiana (22).......................................... 412 3,080 176,558 2,903,442 5,667 1.95
Maine (23).............................................. 31 934 13,980 920,020 425 0.46
Maryland (24)........................................... 344 3,743 200,893 3,542,107 3,677 1.04
Massachusetts (25)...................................... 299 4,617 173,969 4,443,031 2,983 0.67
Michigan (26) ,......................................... 438 6,971 234,030 6,736,970 5,144 0.76
Minnesota (27).......................................... 127 3,326 64,721 3,261,279 1,448 0.44
Mississippi (28)........................................ 262 1,913 134,619 1,778,381 3,183 1.79
Missouri (29)........................................... 241 3,899 122,193 3,776,807 2,978 0.79
Montana (30)............................................ 22 618 11,391 606,609 294 0.48
Nebraska (31)........................................... 22 1,181 11,909 1,169,091 240 0.21
Nevada (32)............................................. 111 1,181 48,152 1,132,848 1,536 1.36
New Hampshire (33)...................................... 17 845 12,426 832,574 185 0.22
New Jersey (34)......................................... 764 5,973 433,887 5,539,113 8,357 1.51
New Mexico (35)......................................... 78 1,156 33,655 1,112,345 965 0.86
New York (36)........................................... 3,414 13,658 1,943,173 11,714,827 35,735 3.05
North Carolina (37)..................................... 532 5,314 283,735 5,030,265 6,138 1.22
North Dakota (38)....................................... 10 466 3,624 462,376 134 0.29
Ohio (39)............................................... 318 8,248 153,259 8,094,741 3,845 0.48
Oklahoma (40)........................................... 231 2,378 96,822 2,281,178 3,116 1.37
Oregon (41)............................................. 146 2,303 74,558 2,228,442 1,825 0.82
Pennsylvania (42)....................................... 583 9,154 360,365 8,793,635 6,047 0.69
Rhode Island (44)....................................... 47 757 30,030 726,970 506 0.70
South Carolina (45)..................................... 362 2,712 195,197 2,516,803 4,356 1.73
South Dakota (46)....................................... 26 513 7,766 505,234 350 0.69
Tennessee (47).......................................... 494 3,878 269,756 3,608,244 5,875 1.63
Texas (48).............................................. 2,276 13,077 1,139,601 11,937,399 27,853 2.33
Utah (49)............................................... 47 1,236 22,782 1,213,218 446 0.37
Vermont (50)............................................ 10 434 2,589 431,411 162 0.37
Virginia (51)........................................... 330 4,949 214,873 4,734,127 3,311 0.70
Washington (53)......................................... 241 3,935 135,654 3,799,346 2,621 0.69
West Virginia (54)...................................... 80 1,393 38,315 1,354,685 941 0.69
Wisconsin (55).......................................... 104 3,735 47,634 3,687,366 1,332 0.36
Wyoming (56)............................................ 12 339 3,624 335,376 190 0.57
--------------------------------------------------------------------------------------------------------------------------------------------------------
a Expressed in thousands.
b Based on a 6.31% rate of TB infection in the U.S.
Table V-7(c).--Estimates of Annual Background TB Infection Rates
[Referent Year 1994 a]
Annual
TB cases Population Population Population at Estimate of population
State reported in size currently risk new infections rate of TB
1994 infected b infection,
Ai Ni Pi (1993) Xi Ii Bi
--------------------------------------------------------------------------------------------------------------------------------------------------------
Alabama (01)............................................ 413 3,139 262,512 2,876,488 4,685 1.63
Alaska (02)............................................. 78 414 29,168 384,832 1,167 3.03
Arizona (04)............................................ 233 2,936 124,107 2,811,893 2,801 1.00
Arkansas (05)........................................... 235 1,813 112,669 1,700,332 2,843 1.67
California (06)......................................... 4,291 22,754 2,595,951 20,158,049 46,720 2.32
Colorado (08)........................................... 90 2,686 55,476 2,630,524 1,024 0.39
Connecticut (09)........................................ 144 2,487 85,216 2,401,784 1,629 0.68
Delaware (10)........................................... 51 531 27,452 503,508 661 1.31
D.C..................................................... 116 451 84,072 366,928 1,131 3.08
Florida (12)............................................ 1,675 10,691 888,766 9,802,234 20,137 2.05
Georgia (13)............................................ 676 5,162 416,359 4,745,641 6,884 1.45
Hawaii (15)............................................. 234 875 139,539 735,451 2,526 3.43
Illinois (17)........................................... 1,021 8,669 653,134 8,015,866 10,721 1.34
[[Page 54202]]
Indiana (18)............................................ 201 4,279 136,117 4,142,883 2,029 0.49
Iowa (19)............................................... 62 2,180 32,600 2,067,401 849 0.41
Kansas (20)............................................. 77 1,864 38,891 1,825,109 1,052 0.58
Kentucky (21)........................................... 316 2,857 213,327 2,643,673 3,187 1.21
Louisiana (22).......................................... 412 3,080 195,025 2,884,975 5,496 1.91
Maine (23).............................................. 31 934 15,442 918,558 413 0.45
Maryland (24)........................................... 344 3,743 221,905 3,521,095 3,484 0.99
Massachusetts (25)...................................... 299 4,617 192,166 4,424,834 2,793 0.63
Michigan (26)........................................... 438 6,971 258,508 6,712,492 4,925 0.73
Minnesota (27).......................................... 127 3,326 71,490 3,254,510 1',377 0.42
Mississippi (28)........................................ 262 1,913 148,700 1,764,300 3,057 1.73
Missouri (29)........................................... 241 3,899 134,973 3,764,027 2,865 0.76
Montana (30)............................................ 22 618 12,582 605,418 286 0.48
Nebraska (31)........................................... 22 1,181 13,154 1,167,846 227 0.20
Nevada (32)............................................. 111 1,181 53,189 1,127,811 1,491 1.32
New Hampshire (33)...................................... 17 845 13,726 831,274 178 0.21
New Jersey (34)......................................... 764 5,973 479,270 5,493,730 7,938 1.44
New Mexico (35)......................................... 78 1,156 37,175 1,118,825 922 0.82
New York (36)........................................... 3,414 13,658 2,146,421 11,511,421 33,696 2.92
North Carolina (37)..................................... 532 5,314 313,413 5,000,587 5,859 1.17
North Dakota (38)....................................... 10 466 4,003 461,997 129 0.28
Ohio (39)............................................... 318 8,248 169,289 8,078,711 3,678 0.46
Oklahoma (40)........................................... 231 2,378 106,949 2,271,051 3,011 1.33
Oregon (41)............................................. 146 2,303 82,357 2,220,643 1,760 0.80
Pennsylvania (42)....................................... 583 9,154 398,057 8,755,943 5,722 0.66
Rhode Island (44)....................................... 47 757 33,171 723,829 483 0.67
South Carolina (45)..................................... 362 2,712 215,614 2,496,386 4,188 1.68
South Dakota (46)....................................... 26 513 8,579 504,421 334 0.67
Tennessee (47).......................................... 494 3,878 297,971 3,580,029 5,641 1.58
Texas (48).............................................. 2,276 13,077 1,258,799 11,818,201 26,746 2.26
Utah (49)............................................... 47 1,236 25,165 1,210,835 408 0.34
Vermont (50)............................................ 10 434 2,860 431,140 158 0.37
Virginia (51)........................................... 330 4,949 237,347 4,711,653 3,126 0.66
Washington (53)......................................... 241 3,935 149,843 3,785,157 2,485 0.66
West Virginia (54)...................................... 80 1,393 42,322 1,350,679 896 0.66
Wisconsin (55).......................................... 104 3,735 52,617 3,682,383 1,283 0.35
Wyoming (56)............................................ 12 339 4,003 334,997 185 0.55
--------------------------------------------------------------------------------------------------------------------------------------------------------
a Expressed in thousands.
b Based on 6.97% rate of TB infection prevalence in the U.S. (maximum estimate).
Step 5 Model validation:
An alternative, but less sophisticated, way to estimate annual risk
of infection, if prevalence is known in a specific age group, is to use
the following formula:
Annual Rate of Infection = -ln(1-P)/d (8)
Where:
P is the percent prevalence of infection and
d is the average age of the population (Ex. 7-265).
In order to validate the model used by OSHA to estimate background
infection rates, estimates of TB infection prevalence for 1994 were
used to calculate predicted infection rates using equation (8). Based
on Murray's model, TB infection prevalence is expected to range from
6.31% to 6.97% in 1994 among adults (18+). Using these figures and
assuming the average age to be 45 years, formula (8) predicts that
infection rates can range from 1.45 to 1.61 per 1,000. These results
are in close agreement with OSHA's weighted average estimate of the
national TB infection rate, which is 1.46 per 1,000.
4. Occupational Risk Estimations
OSHA used the three different data sources to obtain estimates of
risk of TB infection for health care employees: the Washington State
data, the North Carolina study, and the NIOSH Health Hazard Evaluation
(HHE) from Jackson Memorial Hospital (Exs. 7-263, 7-7, 7-108). The
Washington State data represent workplaces located in low TB prevalence
areas, where TB infection control measures and engineering controls are
required by state health regulations. The North Carolina data represent
workplaces located in areas with moderate TB prevalence and inadequate
TB infection control programs. Finally, the Jackson Memorial Hospital
data are representative of county hospitals serving high-risk patients
whose employees have a high frequency of exposure to infectious TB.
These data sources provide information on the magnitude of the expected
excess risk in three different environments, and are used to provide a
range of possible values of excess risk.
Based on the Washington State data, the annual risk is expected to
be 1.5 times the background rate for hospital employees, approximately
11 times the background rate for long-term care employees, 6 times the
background rate for home health care workers, and double the background
rate for home care employees. Based on the North Carolina data, the
annual risk is
[[Page 54203]]
expected to be approximately 5 times the background rate. Based on the
Jackson Memorial Hospital data, the annual risk is expected to be
approximately 9 times the background.
Estimates of expected excess risk of TB infection for workers with
occupational exposure by state are calculated by applying the excess
relative risk ratios, derived from the three occupational studies, to
the overall background rate of infection for each state and are
presented in table V-8(a)--table V-8(c). A range of excess risk of TB
infection due to occupational exposure is constructed by using the
minimum and maximum estimates of excess risk among all states for each
data source. These results are presented in table V-9 and table V-10
for workers in hospitals and for workers in other work settings,
respectively.
BILLING CODE 4510-26-P
[GRAPHIC] [TIFF OMITTED] TP17OC97.002
[[Page 54204]]
[GRAPHIC] [TIFF OMITTED] TP17OC97.003
[[Page 54205]]
[GRAPHIC] [TIFF OMITTED] TP17OC97.004
BILLING CODE 4510-26-C
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Table V-9.--Occupational Risk Estimates for Hospital Employees a
----------------------------------------------------------------------------------------------------------------
Range of excess occupational
Overall risk/ Background Excess risk risk d
Source (exposed) risk based on based on study -------------------------------
study (percent) Annual Lifetime
----------------------------------------------------------------------------------------------------------------
Washington State 1994 data...... 1.24/1000 0.88/1000 47 0.09-1.66 4.1-72.2
North Carolina Western Counties. b 5.98/1000 d 1.20/1000 398 0.77-14.1 34.2-472
Jackson Memorial (1991)......... 31.7/1000 3.5/1000 795 1.54-28.2 67.1-723
----------------------------------------------------------------------------------------------------------------
a Background TB infection rate ranges from 0.194 to 3.542 per 1,000 at risk for TB infection.
b Ajusted for 1994, i.e., 5.98=7.2*(532/641)
c The range reflects regional differences in TB prevalence as well as inherent uncertainty in the estimate of TB
infection prevalence in the U.S., as estimated by Dr. Christopher Murray, and used in the internal
calculations of annual background TB infection rate.
d State-wide estimate of population risk for North Carolina, shown in Table V-3(a).
Table V-10.--Occupational Risk Estimates for Other Work Settings a,b
----------------------------------------------------------------------------------------------------------------
Range of excess occupational
Overall risk/ Background Excess risk risk d
Type (exposed) risk State- based on study -------------------------------
wide c (percent) Annual Lifetime
----------------------------------------------------------------------------------------------------------------
Long-term Care.................. 9.8/1000 0.8756/1000 1019 1.98-36.1 85-807
Home Health Care................ 5.06/1000 0.8756/1000 478 0.93-16.9 40.9-526
Home Care....................... 1.86/1000 0.8756/1000 112 0.22-3.97 9.7-164
----------------------------------------------------------------------------------------------------------------
a Background TB infection rate ranges from 0.194 to 3.542 per 1,000 employees at risk of infection.
b Based on the Washington State data.
c Background rate for this analysis is assumed to be the same as in the case-control analysis of the Washington
State hospital data (i.e. 0.8756 per 1,000 employees).
d The range reflects regional differences in TB prevalence as well as inherent uncertainty in the estimate of TB
infection prevalence in the U.S., as estimated by Dr. Christopher Murray, and used in the internal
calculations of annual background TB infection rate.
Lifetime estimates of the excess risk of TB infection were
estimated based on the annual excess risk by using the formula {1-(1-p)
45}, where p is the annual excess risk. Lifetime excess
estimates of TB infection are presented in table V-9 and table V-10.
Lifetime risk estimates of developing active TB are calculated from
lifetime risk estimates of TB infection assuming that, once infected,
there is a 10% likelihood of progressing to active TB; these estimates
are presented in table V-11 and table V-12. Further, the risk of death
caused by TB is calculated from the lifetime estimates of active TB
using OSHA's estimate of the TB case fatality rate (also presented in
table V-11 and table V-12). The methodology used to estimate a TB case
fatality rate is presented below.
Table V-11.--Lifetime Occupational Risk Estimates for Hospital Employees a b c
----------------------------------------------------------------------------------------------------------------
Active disease Death caused
Source TB infection d e by TB
----------------------------------------------------------------------------------------------------------------
Washington State (1994)......................................... 4.1-72.2 0.4-7.2 0.03-0.6
North Carolina Western Region................................... 34.2-472 3.4-47.2 0.3-3.7
Jackson Memorial Hospital (Miami)............................... 67.1-723 6.7-72.3 0.5-5.6
----------------------------------------------------------------------------------------------------------------
a Risk estimates reflect excess risk due to occupational exposure and are expressed per 1,000 employees at risk.
b Estimates of death caused by TB due to occupational exposure are derived based on an estimated TB case death
rate of 77.85 per 1,000 TB cases and are estimated by multiplying the lifetime active disease rate by .07785.
c The ranges of risk presented in this TABLE reflect expected variance in the annual background TB infection
rate by state. They are estimated based on the assumption that the annual background TB infection rate ranges
from 0.194 to 1.542 per 1,000 employees at risk.
d Lifetime infection rate is estimated by (1-(1-p) 45), where p is the annual excess TB infection rate due to
occupational exposure.
e Lifetime active disease rate is estimated to be 10% of lifetime infection rate.
Table V-12--Lifetime Occupational Risk Estimates for Employees in Other Work Settings a b c
----------------------------------------------------------------------------------------------------------------
Active disease Death caused
Work setting TB infection d e by TB
----------------------------------------------------------------------------------------------------------------
Long-term Care.................................................. 85-807 8.5-80.7 0.7-6.2
Home Health Care................................................ 40.9-536 4.1-53.6 0.3-4.2
Home Care....................................................... 9.7-164 1.0-16.4 0.1-1.3
----------------------------------------------------------------------------------------------------------------
a Risk estimates reflect excess risk due to occupational exposure and are expressed per 1,000 employees at risk
of TB infection.
b Estimates of death caused by TB due to occupational exposure are derived based on an estimated TB case death
rate of 77.85 per 1,000 cases and are estimated by multiplying the lifetime active disease rate by .07785.
c The ranges of risk presented in this TABLE reflect expected variance in the annual background TB infection
rate by state. They are estimated based on the assumption that the annual background TB infection rate ranges
from 0.194 to 3.542 per 1,000 employees at risk.
d Lifetime infection rate is estimated by (1-(1-p)\45\), where p is the annual excess TB infection rate due to
occupational exposure.
e Lifetime active disease rate is estimated to be 10% of lifetime infection rate.
[[Page 54207]]
As outlined in the Health Effects section, several possible
outcomes are possible following an infection. Approximately 90% of all
infections never progress to active disease. An estimated 10% of
infections is expected to progress to active disease; most of these
cases are successfully treated. However, a percentage of active TB
cases develop further complications. Approximately 7.8% of active TB
cases may take a more severe clinical course and lead to death. The TB
case fatality rate was estimated using information on reported deaths
caused by TB from table 8-5 of the Vital Statistics for the U.S. and
cases of TB reported in CDC's TB Surveillance system for 1989 through
1991 (Exs. 7-270, 7-264). As shown in table V-13, the TB case death
rate ranged from 69.94 to 89.18 per 1,000 with a 3-year average of
77.85 per 1,000 TB cases. The Agency used the 3-year average (77.85 per
1,000) for its estimate of deaths caused by TB. This estimate is in
close agreement with published results from a retrospective cohort
study conducted in Los Angeles County on TB cases in 1990 (Ex. 7-268).
In this study, all confirmed TB cases reported in the county in 1990
were tracked and the number of deaths where TB was the direct or
contributing cause was ascertained. ``Contributing cause'' was defined
as a case of TB of such severity that it would have caused the death of
the patient had the primary illness not caused death earlier. Of the
1,724 cases included in the study, TB was considered the cause of death
or the contributing cause of death in 135 cases (78.31 per 1,000).
Table V-13.--TB Case Death Rates for Adults (18+)
----------------------------------------------------------------------------------------------------------------
Number of Number of TB TB case death
Year deaths a cases b rate c
----------------------------------------------------------------------------------------------------------------
1991............................................................ 1,700 24,307 69.94
1990............................................................ 1,796 23,795 75.48
1989............................................................ 1,956 21,934 89.18
3-year Average.................................................. 1,817 23,345 77.85
----------------------------------------------------------------------------------------------------------------
a Source: Vital Statistics for the U.S., Table 8-5, (age 20+).
b Source: CDC, TB surveillance system, (age 18+).
c Rate expressed per 1,000 TB cases. Any deaths caused by TB in persons 18 or 19 years of age are not included
in the numerator.
National estimates of annual and lifetime risk for TB infection,
active disease and death caused by TB due to occupational exposure are
computed as weighted averages of the state estimates and are presented
in table V-14.
Table V-14.--Average Occupational Risk Estimates a, b per 1,000 Workers at Risk
----------------------------------------------------------------------------------------------------------------
Annual TB Lifetime TB Lifetime Death caused
Work setting infection infection active TB by TB c
----------------------------------------------------------------------------------------------------------------
Hospitals:
WA.......................................... 0.68 30 3.0 0.2
NC.......................................... 5.7 219 22.0 1.7
JM.......................................... 11.8 386 38.6 3.0
Long-term Care.................................. 14.6 448 44.8 3.5
Home Health Care................................ 6.9 225 25.5 2.0
Home Care....................................... 1.6 69 6.9 0.5
----------------------------------------------------------------------------------------------------------------
a Weighted by each state's population in 1994.
b Risk estimates reflect excess risk due to occupational exposure and are expressed per 1,000 employees at risk.
c Number of deaths caused by TB due to occupational exposure are derived based on an estimated TB case death
rate of 77.85 per 1,000 cases and are computed by multiplying the lifetime active disease rate by .07785.
(a) Risk Estimates for Hospital Employees: Logistic regression
analysis of the Washington state hospital data indicated an increase in
annual risk (47% above background) for employees with potential
exposure to TB. For this particular analysis the control group was
defined as those hospitals with no-known TB patients that are located
in counties that did not report any active TB cases in 1994. However,
an increased risk of 47% above background in the annual infection rate
is expected to produce a range of 4 to 72 TB infections per 1000
exposed workers in a working lifetime, which could result in as many as
7 cases of active TB and approximately 1 death per 1,000 exposed
workers.
Based on the survey of hospitals in North Carolina's western
region, the expected overall risk due to occupational exposure is
estimated to be 4 times the background rate. This results in an
expected range of lifetime risk between 34 and 472 infections per 1,000
employees at risk for TB infection. Lifetime estimates of active TB
cases resulting from these infections are expected to range between 3
and 47, resulting in as many as 4 deaths per 1,000 exposed employees at
risk of TB infection. As done previously, the North Carolina study
results were adjusted to reflect 1994 TB disease trends.
Based on the data from Jackson Memorial Hospital, the overall risk
due to occupational exposure is estimated to be 8 times the background
rate. This results in an expected range of lifetime risk between 67 and
723 infections per 1,000 employees at risk. Lifetime estimates of the
number of active TB case per 100 exposed workers are expected to range
between 7 and 72, resulting in as many as 6 deaths per 1,000 exposed
employees at risk for TB infection.
In summary, table V-9 and table V-14 show that the annual
occupational risk of infection is expected to range:
(a) From .09 to 1.66 with a weighted average of 0.68 per 1,000 for
workplaces located in relatively low TB prevalence areas, and where TB
infection measures and engineering controls are required;
(b) From 0.77 to 14.1 with a weighted average of 5.7 per 1,000 for
workplaces located in areas with moderate TB prevalence and inadequate
TB control programs; and
(c) From 1.54 to 28 with a weighted average of 11.8 per 1,000 for
workplaces
[[Page 54208]]
located in high TB prevalence areas, serving high risk patients, with
high frequency of exposure to infectious TB.
Similarly, the lifetime occupational risk is expected to range:
(a) From 4 to 72 with a weighted average of 30 per 1,000 for
workplaces located in relatively low TB prevalence areas, and where TB
infection measures and engineering controls are required;
(b) From 34 to 472 with a weighted average of 219 per 1,000 for
workplaces located in areas with moderate TB prevalence and inadequate
TB control programs; and
(c) From 67 to 723 with a weighted average of 386 per 1,000 for
workplaces located in high TB prevalence areas, serving high risk
patients, with high frequency of exposure to infectious TB.
Risk estimates derived from either study (Washington State or North
Carolina) represent an overall rate of occupational risk, because both
studies include PPD skin testing results from the entire hospital
employee population, whereas the Jackson Memorial study addresses the
occupational risk to workers where exposure to infectious TB is highly
probable.
Although the exact compliance rate is not known, hospitals in
Washington State have been required to implement the CDC TB guidelines
with respect to engineering controls (requiring isolation rooms with
negative pressure) and infection control measures (advocating early
patient identification, employee training, respiratory protection, and
PPD testing).
Neither the facilities in North Carolina nor Jackson Memorial had
engineering controls fully implemented at the time these data were
collected. Early identification of suspect TB patients has always been
recommended in North Carolina. However, engineering controls in
isolation rooms were either not present or did not function properly
because of modifications in the physical structure of the building
(i.e., isolation rooms had been subdivided using partitions, air ducts
had been re-directed because of remodeling, etc.). Tuberculin skin
testing was very inconsistent and sporadic. In addition, employee
training and use of respiratory protection were not emphasized.
By 1991, Jackson Memorial had most of the engineering controls in
place in the HIV ward (where the first outbreak took place) and in
selected areas with high TB exposure, but not in the entire hospital.
However, the staff training program was still being developed and
respiratory protection was not always adequate. Although exposures had
been greatly reduced, ``high risk'' procedures were still being
performed in certain areas of the hospital without adequate engineering
controls, such as the Special Immunology clinic where HIV-TB patients
received pentamidine treatments. Like the hospitals in the North
Carolina study, Jackson Memorial represents a working environment that
serves a patient population known to have high TB prevalence. In
addition, Jackson Memorial only tested employees with patient contact
in areas where active TB had been detected.
(b) Risk Estimates for Workers in Other Work Settings: In long-term
care facilities for the elderly there is also a significantly increased
likelihood that employees will encounter individuals with infectious
TB. Persons over the age of 65 constitute a large proportion of the TB
cases in the United States. In 1987, CDC reported that persons aged 65
and over accounted for 27% (6150) of the reported cases of active TB in
the U.S., although they account for only 12% of the U.S. population.
Many of these individuals were infected in the past and advancing age
and decreasing immunocompetence have caused them to develop active
disease. In 1990 the CDC estimated that approximately 10 million people
were infected with TB. As the U.S. population steadily ages, many of
these latent infections may progress to active disease. Because elderly
persons represent a large proportion of the nation's nursing home
residents and because the elderly represent a large proportion of the
active cases of TB, there is an increased likelihood that employees at
long-term care facilities for the elderly will encounter individuals
with infectious TB.
Similarly, there are other occupational settings that serve high-
risk client populations and thus have an increased likelihood of
encountering individuals with infectious TB. For example, hospices,
emergency medical services, and home-health care services provide
services to client populations similar to those in hospitals and thus
are likely to experience similar risks.
OSHA used information from the 1994 Washington state PPD skin
testing survey to estimate occupational risk for workers in long-term
care, home health care, and home care. Annual estimates of excess risk
for TB infection are presented in TABLE V-10 and lifetime estimates for
TB infection, active TB, and death caused by occupational TB are
presented in TABLE V-12.
Based on the Washington State data, the overall annual excess risk
for TB infection is estimated to be 10-fold over background for workers
in long-term care. This results in an expected range of lifetime risk
of between 85 and 800 infections per 1,000 employees at risk for TB
infection. Lifetime estimates of the number of active TB cases
resulting from these infections range from 9 to 81 and are projected to
cause as many as 6 deaths per 1,000 exposed employees at risk of TB
infection. Similarly, the overall annual excess risk of TB infection
for workers in home health care is estimated to be approximately 500%
above background. This results in an expected range of lifetime risk of
between 41 and 536 infections per 1,000 employees at risk for TB
infection. Lifetime estimates of the number of active TB cases range
from 4 to 54 per 1,000, and are projected to cause as many as 4 deaths
per 1,000 exposed employees at risk of TB infection. Similarly, the
overall annual excess risk of TB infection for workers in home care is
estimated to be approximately 100% above background. This results in an
expected range of lifetime risk of between 10 and 164 infections per
1,000 employees at risk for TB infection. Lifetime estimates of the
number of active TB cases range from 1 to 16, and are expected to
result in approximately 1 death per 1,000 exposed employees at risk of
TB infection.
Clearly, employees in all three groups (long-term care for the
elderly, home health care, and home care) have higher risks than
hospital employees in Washington. This could be attributed, in part, to
the lack of engineering controls in these work settings. That
respirators may be used only intermittently may also play a role.
Although workers in these three groups are encouraged by local health
authorities to use respiratory protection while tending to a suspect TB
patient, the actual rate of respirator usage is difficult to ascertain.
A third factor that may contribute to higher risk in these work
settings is delayed identification of suspect TB patients due to
confounding symptoms presented by the individuals. For example, many
long-term care residents exhibit symptoms of persistent coughing from
decades of smoking. Consequently, an individual in long-term care with
a persistent cough may be infectious for several days before he or she
is identified as having suspected infectious TB.
Qualitative Assessment of Risk for Other Occupational Settings
The quantitative estimates of the risk of TB infection discussed
above are based primarily upon data from hospitals and selected other
health care settings. Data from hospitals and certain health care
settings were selected because OSHA believes that these data
[[Page 54209]]
represent the best information available to the Agency for purposes of
quantifying the occupational risks of TB infection and disease.
However, as discussed above, it is their exposure to aerosolized M.
tuberculosis that places these workers at risk of infection and not
factors unique to these particular kinds of health care activities.
Thus, OSHA believes that the risk estimates derived from hospitals and
selected other work settings can be used to describe the potential
range of risks for other health care and other occupational settings in
which workers can reasonably anticipate frequent and substantial
exposure to aerosolized M. tuberculosis.
In order to extrapolate the quantitative risk estimates calculated
for hospital employees and other selected health care settings, OSHA,
as a first step, identified risk factors that place employees at risk
of exposure. Some amount of exposure to TB could occur in any workplace
in the United States. TB is an infectious disease that occurs in the
community and thus, individuals may bring the disease into their own
workplace or to other businesses or work settings that they may visit.
However, there are particular kinds of work settings where risk factors
are present that substantially increase the likelihood that employees
will be frequently exposed to aerosolized M. tuberculosis. First among
these factors is the increased likelihood of exposure to individuals
with active, infectious TB. Individuals who are infected with TB have a
higher risk of developing active TB if they are (1) immunocompromised
(e.g., elderly, undergoing chemotherapy, HIV positive), (2) intravenous
drug users, or (3) medically underserved and of generally poor health
status (Exs. 6-93 and 7-50). Thus, in work settings in which the client
population is composed of a high proportion of individuals who are
infected with TB, are immunocompromised, are intravenous drug users or
are of poor general health status, there is a greatly increased
likelihood that employees will routinely encounter individuals with
infectious TB and be exposed to aerosolized M. tuberculosis. A second
factor that places employees at high risk of exposure to aerosolized M.
tuberculosis is the performance of high-hazard procedures, i.e.,
procedures performed on individuals with suspected or confirmed
infectious TB where there is a high likelihood of the generation of
droplet nuclei. A third factor that places employees at risk of
exposure is the environmental conditions at the work setting. Work
settings that have overcrowded conditions or poor ventilation will
facilitate the transmission of TB. Thus, given that a case of
infectious TB does occur, the conditions at the work setting itself may
promote the transmission of disease to employees who share airspace
with the individual(s) with infectious TB.
The second step in extrapolating the quantitative risks is to
identify the types of work settings which have some or all of the risk
factors outlined above. Once these work settings have been identified,
OSHA believes that it is reasonable to assume that the quantitative
risk estimates calculated for hospitals and other selected health care
settings can be used to describe the risks in the identified work
settings.
Correctional Facilities
Employees in correctional facilities or other facilities that house
inmates or detainees have an increased likelihood of frequent exposure
to individuals with infectious TB. Many correctional facilities have a
higher incidence of TB cases in comparison to the incidence in the
general population. In 1985, the CDC estimated that the incidence of TB
among inmates of correctional facilities was more than three times
higher than that for nonincarcerated adults aged 15-64 (Ex. 3-33). In
particular, in states such as New Jersey, New York, and California, the
increased incidence of annual TB cases in correctional facilities
ranged from 6 to 11 times greater than that of the general population
for their respective states (Exs. 7-80 and 3-33). A major factor in the
increased incidence of TB cases in correctional facilities is the fact
that the population of correctional facilities is over-represented by
individuals who are at greater risk of developing active disease, e.g.,
persons from poor and minority groups who may suffer from poor
nutritional status and poor health care, intravenous drug users, and
persons infected with HIV. Similarly, certain types of correctional
facilities, such as holding facilities associated with the Immigration
and Naturalization Service, may have inmates/detainees from countries
with a high incidence of TB. For foreign-born persons arriving in the
U.S., the case rate of TB in 1989 was estimated to be 124 per 100,000,
compared to an overall TB case rate of 9.5 per 100,000 for the U.S.
(Ex. 6-26). Moreover, in the period from 1986 to 1989, 22% of all
reported cases of TB disease occurred in the foreign-born population.
Given the increased prevalence of individuals at risk for developing
active TB, there is an increased likelihood that employees working in
these facilities will encounter individuals with infectious TB. In
addition, environmental factors such as overcrowding and poor
ventilation facilitate the transmission of TB. Thus, given that a case
of infectious TB does occur, the conditions in the facility itself
promote the transmission of the disease to other inmates and employees
in the facility who share airspace.
As discussed in the Health Effects section, a number of outbreak
investigations (Exs. 6-5, 6-6) have shown that where there has been
exposure to aerosolized M. tuberculosis in correctional facilities, the
failure to promptly identify individuals with infectious TB and provide
appropriate infection control measures has resulted in employees being
infected with TB. These studies demonstrate that, as in hospitals or
health care settings, where there is exposure to aerosolized TB bacilli
and where effective control measures are not implemented, exposed
employees are at risk of infection. Thus, estimates based on the risk
observed among employees in hospitals and in selected other work
settings that involve an increased likelihood of exposure can be
appropriately applied to employees in correctional facilities.
Recently, scientists at NIOSH have completed a prospective study of
the incidence of TB infection among New York State correctional
facilities employees (Ex. 7-288). This study is the first prospective
study of TB infection among employees in correctional facilities in an
entire state. Other studies have reported on contact investigations,
which seek to identify recent close contacts with an index case and
determine who might subsequently have been infected. Studies based on
contact investigations have the advantage of a good definition of
potential for exposure and they serve to identify infected persons for
public health purposes. On the other hand, prospective studies of an
entire working group have the advantage of covering the entire
population potentially at risk, of considering all inmate cases
simultaneously as potential sources of infection, and, most
importantly, of permitting the calculation of incidence rates and risk
attributable to occupational exposure.
Following an outbreak of active TB among inmates that resulted in
transmission to employees in 1991, the state of New York instituted a
mandatory annual tuberculin skin testing program to detect TB infection
among employees. The authors used data from the first two years of
testing to estimate the incidence of TB infection
[[Page 54210]]
among 24,487 employees of the NY Department of Corrections. Subjects
included in the study had to have two sequential PPD skin tests, have a
negative test the first year, and have complete demographic
information. The overall conversion rate was estimated to be 1.9%.
Preliminary results show that after controlling for age, ethnicity,
gender, and residence in New York City, corrections offices and medical
personnel, working in prisons with inmate active TB cases, had odds
ratios of TB infection of 1.64 and 2.39, respectively, compared to
maintenance and clerical personnel who had little opportunity for
prisoner contact. Based on these results, the annual excess risk due to
occupational exposure is estimated to be 1.22% and 2.64% for
corrections officers and medical personnel, respectively. This
translates into lifetime occupational risks of 423 and 700 per 1,000
exposed employees, respectively. In prisons with no known inmate TB
cases, there were no significant differences in TB infection rates
among employees in different job categories.
Homeless Shelters
Employees in homeless shelters also have a significantly increased
likelihood of frequent exposure. A high prevalence of TB infection and
disease is common in many homeless shelters. Screening in selected
shelters has shown the prevalence of TB infection to range from 18 to
51% (Ex. 6-15). Many shelter residents also possess characteristics
that impair their immunity and thus place them at greater risk of
developing active disease. For example, homeless persons often suffer
from poor nutrition and poor overall health status, and they also have
poor access to health care. In addition, they may suffer from
alcoholism, drug abuse and infection with HIV. Screening of selected
shelters has shown the prevalence of active TB disease to range from
1.6 to 6.8% (Ex. 6-15). Thus, there is an increased likelihood that
employees at homeless shelters will frequently encounter individuals
with infectious TB in the course of their work.
In addition, as in the case for correctional facilities, homeless
shelters also tend to be overcrowded and have poor ventilation, factors
that promote the transmission of disease and place shelter residents
and employees at risk of infection. Outbreaks reported among homeless
shelters (Exs. 7-51, 7-75, 7-73, 6-25) also provide evidence that where
there is exposure to individuals with infectious TB and effective
infection control measures are not implemented, employees are at risk
of infection. It is reasonable to assume, therefore, that risk
estimates calculated for hospital employees who have an increased
likelihood of exposure to individuals with infectious TB can be used to
estimate the risks for homeless shelter employees.
Facilities That Provide Treatment for Drug Abuse
Employees in facilities that provide treatment for drug abuse have
an increased likelihood of frequent exposure to individuals with
infectious TB. Surveys of selected U.S. cities by the CDC have shown
the prevalence of TB infection among the clients of drug treatment
centers to range from approximately 10% to 13% (Ex. 6-8). Clients of
these centers are also generally at higher risk of developing active
disease. The clients typically come from medically underserved
populations and may suffer from poor overall health status. As
discussed in the Health Effects section, drug dependence has also been
shown to be a possible risk factor in the development of active TB.
Moreover, many of the drug treatment center clients are intravenous
drug users and are infected with HIV, placing these individuals at an
increased risk of developing active TB. Given these risk factors for
the clients served at drug treatment centers, there is an increased
likelihood that employees in these work settings will be exposed
frequently to individuals with infectious TB.
Medical Laboratories
Medical laboratory work is a recognized source of occupational
hazards. CDC considers workers in medical laboratories that handle M.
tuberculosis to be at high risk for occupational transmission of TB
either because of the volume of material handled by routine diagnostic
laboratories or the high concentrations of pathogenic agents often
handled in research laboratories.
Few surveys of laboratory-acquired infections have been undertaken;
most reports are of small outbreaks in specific laboratories. Sulkin
and Pike's study of 5,000 laboratories suggested that brucellosis,
tuberculosis, hepatitis, and enteric diseases are among the most common
laboratory-acquired infections (Ex. 7-289). In 1957, Reid noted that
British medical laboratory workers had a risk of acquiring tuberculosis
two to nine times that of the general population (Ex. 7-289). This
result was validated in 1971 by Harrington and Channon in their study
of medical laboratories (Ex. 7-289). A retrospective postal survey of
approximately 21,000 medical laboratory workers in England and Wales
showed a five-times increased risk of developing active TB among these
workers as compared with the general population. Technicians were at
greater risk, especially if they worked in anatomy departments. A
similar survey carried out in 1973 of 3,000 Scottish medical laboratory
workers corroborates the results from England and Wales. Three cases,
one doctor and two technicians, were noted in the 1973 survey, which
resulted in an overall incidence rate of 109 per 100,000 person-years.
The general population incidence rate for active TB was 26 per 100,000
person-years, giving a risk ratio of 4.2 (Ex. 7-289).
The studies reviewed in this section indicate that workers in
medical laboratories with potential for exposure to M. tuberculosis
during the course of their work have a several-fold (ranging from 2- to
9-fold) increased risk of developing active disease compared with the
risk to the general population. Although these studies were conducted
over two decades ago, they represent the most recent data available to
the Agency, and OSHA has no reason to believe that the conditions
giving rise to the risk of infection at that time have changed
substantially in the interim. The Agency is not aware of any more
current data on transmission rates in medical laboratories. OSHA
solicits information on additional studies addressing occupational
exposure to active TB in laboratories; such studies would then be
considered by OSHA in the development of a final rule.
Other Work Settings and Activities
In addition to the information available for correctional
facilities, homeless shelters, and facilities that provide treatment
for drug abuse, there are other work settings and activities where
there is an increased likelihood of frequent exposure to aerosolized M.
tuberculosis. For example, hospices serve client populations similar to
those of hospitals and perform similar services for these individuals.
Individuals who receive care in hospices are likely to suffer from
medical conditions (e.g., HIV disease, end-stage renal disease, certain
cancers) that increase their likelihood of developing active TB disease
once infected. Thus, employees providing hospice care have an increased
likelihood of being exposed to aerosolized M. tuberculosis. CDC has
recommended that hospices follow the same guidelines for controlling TB
that hospitals follow.
Emergency medical service employees also have an increased
likelihood of
[[Page 54211]]
encountering individuals with infectious TB. Like hospices, emergency
medical services cater to the same high risk client populations as
hospitals. Moreover, emergency medical services are often used to
transport individuals identified with suspected or confirmed infectious
TB from various types of health care settings to facilities with
isolation capabilities.
In addition, other types of services (e.g., social services, legal
counsel, education) are provided to individuals who have been
identified as having suspected or confirmed infectious TB and have been
placed in isolation or confined to their homes. Employees who provide
social welfare services, teaching, law enforcement or legal services to
those individuals who are in AFB isolation are exposed to aerosolized
M. tuberculosis. In particular, employees performing high-hazard
procedures are likely to generate aerosolized M. tuberculosis by virtue
of the procedure itself. Thus, employees providing these types of
services also have an increased likelihood of exposure to aerosolized
M. tuberculosis and are therefore likely to experience risks similar to
those described above for hospital workers.
Although they do not have contact with individuals with infectious
TB, employees who repair and maintain ventilation systems which carry
air contaminated with M. tuberculosis and employees in laboratories who
manipulate tissue samples or cultures contaminated with M. tuberculosis
also have an increased likelihood of being exposed to aerosolized M.
tuberculosis. Like employees in the work settings discussed above,
these employees have an increased risk of frequent exposure to
aerosolized M. tuberculosis.
Therefore, OSHA believes that the quantitative risk estimates
derived from data observed among health care workers in the hospital
setting can be generally used to describe the potential range of risks
for workers in other occupational settings where there is a reasonable
anticipation of exposure to aerosolized M. tuberculosis. The
reasonableness of this assumption is supported by the overall weight of
evidence of the available health data. As discussed in the Health
Effects section, epidemiological studies, case reports and outbreak
investigations have shown that in correctional facilities, homeless
shelters, long-term care facilities for the elderly, drug treatment
centers, and laboratories where appropriate TB infection control
programs have not been implemented, employees have become infected with
TB as a result of occupational exposure to individuals with infectious
TB or to other sources of aerosolized M. tuberculosis. Thus, although
the data on employee conversion rates in other work settings cannot be
used to directly quantify the occupational risk of infection for those
work settings, there is strong evidence that employees in various work
settings other than hospitals can reasonably be anticipated to have
exposure to aerosolized M. tuberculosis and that TB can be transmitted
in these workplaces when appropriate TB infection control programs are
not implemented.
VI. Significance of Risk
Section 6(b)(5) of the OSH Act vests authority in the Secretary of
Labor to issue health standards. This section provides, in part, that:
The Secretary, in promulgating standards dealing with toxic
materials or harmful physical agents under this subsection, shall
set the standard which most adequately assures, to the extent
feasible, on the basis of the best available evidence, that no
employee will suffer impairment of health or functional capacity
even if such employee has regular exposure to the hazard dealt with
by such standard for the period of his working life.
OSHA's overall analytical approach to making a determination that
workplace exposure to certain hazardous conditions presents a
significant risk of material impairment of health is a four step
process consistent with interpretations of the OSH Act and rational,
objective policy formulation. In the first step, a quantitative risk
assessment is performed where possible and considered with other
relevant information to determine whether the substance to be regulated
poses a significant risk to workers. In the second step, OSHA considers
which, if any, of the regulatory alternatives being considered will
substantially reduce the risk. In the third step, OSHA examines the
body of ``best available evidence'' on the effects of the substance to
be regulated to set the most protective requirements that are both
technologically and economically feasible. In the fourth and final
step, OSHA considers the most cost-effective way to achieve the
objective.
In the Benzene decision, the Supreme Court indicated when a
reasonable person might consider the risk significant and take steps to
decrease it. The Court stated:
It is the Agency's responsibility to determine in the first
instance what it considers to be ``significant'' risk. Some risks
are plainly acceptable and others are plainly unacceptable. If, for
example, the odds are one in a billion that a person will die from
cancer by taking a drink of chlorinated water, the risk could not be
considered significant. On the other hand, if the odds are one in a
thousand that regular inhalation of gasoline vapors that are 2%
benzene will be fatal, a reasonable person might well consider the
risk significant and take the appropriate steps to decrease or
eliminate it. (I.U.D. v. A.P.I.), 448 U.S. at 655).
The Court indicated that ``while the Agency must support its
findings that a certain level of risk exists with substantial evidence,
we recognize that its determination that a particular level of risk is
`significant' will be based largely on policy considerations.'' The
Court added that the significant risk determination required by the OSH
Act is ``not a mathematical straitjacket'' and that ``OSHA is not
required to support its findings with anything approaching scientific
certainty.'' The Court ruled that ``a reviewing court (is) to give OSHA
some leeway where its findings must be made on the frontiers of
scientific knowledge and that the Agency is free to use conservative
assumptions in interpreting the data with respect to carcinogens,
risking error on the side of overprotection rather than
underprotection.'' (448 U.S. at 655, 656).
As a part of the overall significant risk determination, OSHA
considers a number of factors. These include the type of risk
presented, the quality of the underlying data, the reasonableness of
the risk assessments, and the statistical significance of the findings.
The hazards presented by the transmission of tuberculosis, such as
infection, active disease, and death are very serious, as detailed
above in the section on health effects. If untreated, 40-60% of TB
cases have been estimated to result in death (Exs. 5-80, 7-50, 7-66).
Fortunately, TB is a treatable disease. The introduction of antibiotic
drugs for TB has helped to reduce the mortality rate by 94% since 1953
(Ex. 5-80). However, TB is still a fatal disease in some cases. From
1989-1991 CDC reported 5,452 deaths among adults from TB (see TABLE V-
13, Risk Assessment section). In addition, there has been an increase
in certain forms of drug-resistant TB, such as MDR-TB, in which the
tuberculosis bacilli are resistant to one or more of the front line
drugs such as isoniazid and rifampin, two of the most effective anti-TB
drugs. The information available today is not adequate to estimate the
future course of MDR-TB, but the reduction in the potential of
transmitting this deadly form of the disease is itself another benefit
of this standard. The current data indicate that among MDR-TB cases,
the risk of death is increased compared to drug-susceptible forms of
the disease. A CDC investigation of 8
[[Page 54212]]
outbreaks of MDR-TB revealed that among 253 people infected with MDR-
TB, 75% died within a period 4 to 16 weeks after the time of diagnosis
(Ex. 38-A). MDR-TB may be treated, but due to the difficulty in finding
adequate therapy which will control the bacilli's growth, individuals
with this form of the disease may remain infectious for longer periods
of time, requiring longer periods of hospitalization, additional lost
worktime, and an increased likelihood of spreading TB infection to
others until treatment renders the patient non-infectious. Because of
the difficulty in controlling these drug-resistant forms of the disease
with antibiotics, progressive lung destruction may progress to the
point where it is necessary to remove portions of the lung to treat the
advance of the disease.
The OSH Act directs the Agency to set standards that will
adequately assure, to the extent feasible, that no employee will suffer
``material impairment of health or functional capacity.'' TB infection
represents a material impairment of health that may lead to active
disease, tissue and organ damage, and death. Although infected
individuals may not present any signs or symptoms of active disease,
being infected with TB bacilli is a serious threat to the health status
of the infected individual. Individuals who are infected have a 10%
chance of developing active disease at some point in their life, a risk
they would not have had without being infected. The risk of developing
active disease is even greater for individuals who are
immunocompromised, due to any of a large number of factors. For
example, individuals infected with HIV have been estimated as having an
8-10% risk per year of developing active disease (Ex. 4B).
In addition, since infected individuals commonly undergo treatment
with anti-TB drugs to prevent the onset of active disease, they face
the additional risk of serious side effects associated with the highly
toxic drugs used to treat TB. Preventive treatment with isoniazid, one
of the drugs commonly used to treat TB infection, has been shown in
some cases to result in death from hepatitis or has damaged the
infected person's liver to the extent that liver transplantation was
performed (Ex. 6-10). Thus, the health hazards associated with TB
infection clearly constitute material impairment of health.
Clinical illness, i.e., active disease, also clearly constitutes
material impairment of health. Left untreated, 40 to 60 percent of
active cases may lead to death (Exs. 7-50, 7-66, 7-80). Individuals
with active disease may be infectious for various periods of time and
often must be hospitalized. Active disease is marked by a chronic and
progressive destruction of the tissues and organs infected with the
bacteria. Active TB disease is usually found in the lungs (i.e.,
pulmonary tuberculosis). Long-term damage can result even when cases of
TB are cured; a common result of TB is reduced lung function (impaired
breathing) due to lung damage (Ex. 7-50, pp. 30-31). Inflammatory
responses caused by the disease produce weakness, fever, chest pain,
cough, and, when blood vessels are eroded, bloody sputum. Also, many
individuals have drenching night sweats over the upper part of the body
several times a week. The intensity of the disease varies, ranging from
minimal symptoms of disease to massive involvement of many tissues,
with extensive cavitation and debilitating constitutional and
respiratory problems. Long-term damage can also result from
extrapulmonary forms of active disease; such damage may include mental
impairment from meningitis (infection of membranes surrounding the
brain and spinal cord) and spinal deformity and leg weakness due to
infection of the vertebrae (i.e., skeletal TB) (Ex. 7-50, p. 31).
Active disease is treatable but it must be treated with potent drugs
that have to be taken for long periods of time. The drugs currently
used to treat active TB disease may be toxic to other parts of the
body. Commonly reported side effects of anti-TB drugs include
hepatitis, peripheral neuropathy, optic neuritis, ototoxicity and renal
toxicity (Ex. 7-93). Active disease resulting from infection with MDR-
TB is of even greater concern due to the inability to find adequate
drug regimens. Although OSHA has not been able to precisely quantify
the increase in incidence of MDR-TB, the number of cases of MDR-TB is
clearly on the rise. In these cases, individuals may remain infectious
for longer periods of time and may suffer more long-term damage from
the chronic progression of the disease until adequate therapy can be
identified.
In this standard, OSHA has presented quantitative estimates of the
lifetime risk of TB infection, active disease and death from
occupational exposure to M. tuberculosis. Qualitative evidence of
occupational transmission is also included in OSHA's risk assessment.
In preparing its quantitative risk assessment, OSHA began by
seeking out occupational data associated with TB infection incidence in
order to calculate an estimate of risk for TB infection attributable to
occupational exposure for all U.S. workers. Unfortunately, an overall
national estimate of risk for TB infection attributable to occupational
exposure is not available. CDC, which collects and publishes the number
of active TB cases reported nationwide each year, does not publish
occupational data associated with the incidence of TB infection and
active TB on a nationwide basis. There has been some effort to include
occupational information on the TB reporting forms, but only a limited
number of states are currently using the new forms and capturing
occupational information in a systematic way. In the absence of a
national database, OSHA used two statewide studies, from North Carolina
and Washington (Exs. 7-7, 7-263), and data from an individual hospital,
Jackson Memorial Hospital (Ex. 7-108), on conversion rates of TB
infection for workers in hospitals. The Washington State database also
contained information on three additional occupational groups: long-
term care, home health care and home care employees. OSHA used these
data to model average TB infection rates and estimate the range of
expected risks in the U.S. among workers with occupational exposure to
TB.
The conversion rates in the selected studies were used to estimate
the annual excess relative risk due to occupational exposure, which was
expressed as the percent increase of infection above each study's
control group. In order to estimate an overall range of occupational
risk of TB infection, taking into account regional differences in TB
prevalence in the U.S. and indirectly adjusting for factors such as
socio-economic status, which might influence the rate of TB observed in
different parts of the country, OSHA: (1) Estimated background rates of
infection for each state by assuming that the number of new infections
is functionally related to the number of active cases reported by the
state each year (i.e., the distribution of new infections is directly
proportional to the distribution of active cases), and 2) applied
estimates of the annual excess relative risk, derived from the
occupational studies, to the state background rates to calculate
estimates of excess risk due to occupational exposure by state. Thus,
the excess occupational risk estimates are actually calculated from the
three available studies, on a relative increase basis, and these
relative increases are multiplied by background rates for each state to
derive estimates of excess occupational risk by state. The state
estimates are then used to derive a national estimate of annual
occupational risk of TB infection. Given an annual rate of infection,
the lifetime risk of infection was calculated assuming that workers
[[Page 54213]]
are exposed for 45 years and that the worker's exposure profile and
working conditions remain constant throughout his or her working
lifetime. Lifetime infection rates are then used to calculate the
lifetime risk of developing active disease based on the estimate that
10% of all infections result in active disease. Given a number of
active cases of TB, the number of expected deaths can be calculated
based on the estimated average TB case death rate (i.e., number of TB
deaths per number of active TB cases averaged over 3 years as reported
by CDC).
OSHA estimates that the risk of material impairment of health or
functional capacity, that is, the average lifetime occupational risk of
TB infection for hospital workers ranges from 30 to 386 infections per
1,000 workers who are occupationally exposed to TB. These are different
national averages, each derived by calculating the risk in each state
and weighting it by the state's population. The low end of this range
is derived by using the Washington State data, and is likely to
seriously underestimate the true risk to which workers are exposed.
This is because the Washington data represent occupational exposures
among employees in hospitals which are located in areas of the country
with a low prevalence of active TB and which have implemented TB
controls (e.g., early identification procedures, annual skin testing,
and negative pressure in AFB isolation rooms). The high end of this
range is derived by using the Jackson Memorial Hospital study, and
represents occupational risk for workers in hospitals located in high
TB prevalence areas, serving high risk patients, and with a high
frequency of exposure to infectious TB.
OSHA also used information from the Washington State database to
estimate national average estimates of lifetime risk for workers in
long-term care (i.e., nursing homes), home health care, and home care.
The national average lifetime risk of TB infection is estimated to be
448 per 1,000 for workers in long-term care facilities, 225 per 1,000
for workers in home health care (primarily nursing staff), and 69 per
1,000 for workers in home care. The higher likelihood of occupational
exposure in long-term care facilities (early identification of suspect
TB cases is often difficult among the elderly) and the presence of
fewer engineering controls in these facilities may explain the high
observed occupational risk in that work setting.
The national average lifetime risk of developing active disease
ranges from approximately 3 to 39 cases per 1,000 exposed employees for
workers in hospital settings. Similarly, the average lifetime risk of
active disease is estimated to be approximately 45 per 1,000 for
workers in long-term care, 26 per 1,000 in home health care, and 7 per
1,000 in home care. This range is based on the estimate that 10% of
infections will progress to active disease over one's lifetime. This
risk may be greater for immunocompromised individuals.
The national average lifetime risk of death from TB ranges from 0.2
to approximately 3 deaths per 1,000 exposed employees for workers in
hospital settings. Similarly, the average lifetime risk of death from
TB is estimated to be approximately 3.5 per 1,000 for workers in long-
term care, 2 per 1,000 for workers in home health care, and 0.5 per
1,000 in home care. The lower range of the national lifetime risk of
deaths, 0.2 per 1,000, is based on the Washington State hospital data
where the prevalence of TB is low and infection control measures have
been implemented. Thus, this lower range of risk underestimates the
risk of death from TB for other employees who work in settings where
infection control measures, such as those outlined in this proposed
standard, have not been implemented. The risk assessment data show that
where infection control measures were not in place, the estimated risk
of death from TB was as high as 6 deaths per 1,000 exposed employees.
The quantitative risk estimates are based primarily upon data from
hospitals and selected other work settings. However, it is frequent
exposure to aerosolized M. tuberculosis which places workers at
substantially increased risk of infection and not factors unique to the
health care profession or any job category therein. Qualitative
evidence, such as that from the epidemiological studies, case reports
and outbreak investigations reported for various types of work
settings, as discussed earlier in the Health Effects section, clearly
demonstrates that employees exposed to aerosolized M. tuberculosis have
become infected with TB and have gone on to develop active disease.
These work settings share risk factors that place employees at risk of
transmission. For example, these work settings serve client populations
that are composed of a high prevalence of individuals who are infected
with TB, are immunocompromised, are injecting drug users or are
medically underserved and of poor general health status. Therefore,
there is an increased likelihood that employees in these work settings
will encounter individuals with active TB. In addition, high-hazard
procedures, such as bronchoscopies, are performed in some of these work
settings, which greatly increases the likelihood of generating
aerosolized M. tuberculosis. Moreover, some of the work settings have
environmental conditions such as overcrowding and poor ventilation,
factors that facilitate the transmission of disease. Therefore, OSHA
believes that the quantitative risk estimates based on hospital data
and other selected health care settings can be extrapolated to other
occupational settings where there is a similar increased likelihood of
exposure to aerosolized M. tuberculosis.
Having specific data for non-health care workers and workplace
conditions would add more precision to the quantitative risk
assessment, but that level of detail is not possible with the currently
available information. However, the Agency believes that such a level
of detail is not necessary to make its findings of significant risk
because the risk of infection is based upon occupational exposure to
aerosolized M. tuberculosis. Nevertheless, OSHA seeks information on
conversion rates and the incidence of active disease among employees in
non-health care work settings in order to give more precision to its
estimates of risk.
OSHA's risk estimates for TB infection are comparable to other
risks which OSHA has concluded are significant, and are substantially
higher than the example presented by the Supreme Court in the Benzene
Decision. After considering the magnitude of the risk as shown by the
quantitative and qualitative data, OSHA preliminarily concludes that
the risk of material impairment of health from TB infection is
significant.
OSHA also preliminarily concludes that the proposed standard for
occupational exposure to TB will result in a substantial reduction in
that significant risk. The risk of infection is most efficiently
reduced by implementing TB exposure control programs for the early
identification and isolation of individuals with suspected or confirmed
infectious TB. Engineering controls to maintain negative pressure in
isolation rooms or areas where infectious individuals are being
isolated will reduce the airborne spread of aerosolized M. tuberculosis
and subsequent exposure of individuals, substantially reducing the risk
of infection. In addition, for those employees who must enter isolation
rooms or provide services to individuals with infectious TB,
respiratory protection will reduce exposure to aerosolized M.
tuberculosis and thus reduce the risk of infection.
[[Page 54214]]
Several studies have shown that the implementation of infection
control measures such as those outlined in this proposed standard have
resulted in a reduction in the number of skin test conversions among
employees with occupational exposure to TB. For example, results of a
survey conducted by the Society of Healthcare Epidemiology of America
(SHEA) of its member hospitals (Exs. 7-147 and 7-148) revealed that
among hospitals that treated 6 or more patients with infectious TB per
year there were 68% fewer tuberculin skin test conversions in hospitals
that had AFB isolation rooms with one patient per room, negative
pressure, exhaust air directed outside and six or more air changes per
hour, compared to hospitals that did not have AFB isolation rooms with
these same characteristics. Similarly, an 88% reduction in tuberculin
skin test conversions was observed in an Atlanta hospital after the
implementation of infection control measures such as an expanded
respiratory isolation policy, improved diagnostic and testing
procedures, the hiring of an infection control coordinator, expanded
education of health care workers, increased frequency of tuberculin
skin tests, implementation of negative pressure, and use of submicron
masks for health care workers entering isolation rooms (Ex. 7-173).
Improvements in infection control measures in a Florida hospital after
an outbreak of MDR-TB reduced tuberculin skin test conversions from 28%
to 18% to 0% over three years (Ex. 7-167). These improvements included
improved early identification procedures, restriction of high-hazard
procedures to AFB isolation rooms, increased skin testing, expansion of
initial TB treatment regimens, and daily inspection of negative
pressure in AFB isolation rooms. Thus, these investigations show that
the implementation of infection control measures such as those included
under OSHA's proposed standard for TB can result in substantial
reductions in infections among exposed employees.
As discussed in further detail in the following section of the
Preamble to this proposed standard, OSHA estimates that full
implementation of the proposed standard for TB will result in avoiding
approximately 21,400 to 25,800 work-related infections per year, 1,500
to 1,700 active cases of TB resulting from these infections and 115 to
136 deaths resulting from these active cases. In addition, because the
proposed standard encourages the identification and isolation of active
TB cases in the client populations served by workers in the affected
industries, there will also be non-occupational TB infections that will
be averted. OSHA estimates that implementation of the proposed standard
will result in avoiding approximately 3,000 to 7,000 non-occupational
TB infections, 300 to 700 active cases of TB resulting from these
infections, and 23 to 54 deaths resulting from these active cases. OSHA
preliminarily concludes that the proposed standard for TB will
significantly reduce the risk of infection, active disease and death
from exposure to TB and that the Agency is thus carrying out the
Congressional intent and is not attempting to reduce insignificant
risks.
Although the current OSHA enforcement program, which is based on
the General Duty Clause of the Act, Section 5(a)(1), and the
application of some general industry standards, such as 29 CFR
1910.134, Respiratory Protection, has reduced the risks of occupational
exposure to tuberculosis to some extent, significant risks remain and
it is the Agency's opinion that an occupational health standard
promulgated under section 6(b) of the Act will much more effectively
reduce these risks for the following reasons. First, because of the
standard's specificity, employers and employees are given more guidance
in reducing exposure to tuberculosis. Second, it is well known that a
standard is more protective of employee health than an enforcement
program based upon the general duty clause and general standards.
Unlike the proposed standard, the general duty clause specifies no
abatement methods and the general industry standards do not set forth
abatement methods specifically addressing occupational exposure to TB.
Third, the general duty clause imposes heavy litigation burdens on OSHA
because the Agency must prove that a hazard exists at a particular
workplace and that it is recognized by the industry or the cited
employer. Since the proposed standard specifies both the conditions
that trigger the application of the standard and the employer's
abatement obligations, thereby establishing the existence of the
hazard, no independent proof that the hazard exists in the particular
workplace need be presented. The reduction in litigation burdens will
mean that the Labor Department, as well as the employer, will save time
and money in the investigation and litigation of occupational TB cases.
Finally, the promulgation of this proposed standard will result in
increased protection for employees in state-plan states which, although
not required to adopt general duty clauses, must adopt standards at
least as effective as Federal OSHA standard.
In summary, the institution of the enforcement guidelines has been
fruitful, but it has not eliminated significant risks among
occupationally exposed employees. Therefore, OSHA preliminarily
concludes that a standard specifically addressing the risks of
tuberculosis is necessary to further substantially reduce significant
risk. OSHA's preliminary economic analysis and regulatory flexibility
analysis indicate that the proposed standard is both technologically
and economically feasible. OSHA's analysis of the technological and
economic feasibility is discussed in the following section of the
preamble.
VII. Summary of the Preliminary Economic Analysis and Regulatory
Flexibility Analysis
OSHA is required by the Occupational Safety and Health Act of 1970
and several court cases pertaining to that Act to ensure that its rules
are technologically and economically feasible for firms in the affected
industries. Executive Order (EO) 12866 and the Regulatory Flexibility
Act (as amended) also require Federal agencies to estimate the costs,
assess the benefits, and analyze the impacts on the regulated community
of the regulations they propose. The EO additionally requires agencies
to explain the need for the rule and examine regulatory and non-
regulatory alternatives that might achieve the objectives of the rule.
The Regulatory Flexibility Act requires agencies to determine whether
the proposed rule will have a significant economic impact on a
substantial number of small entities, including small businesses and
small government entities and jurisdictions. For proposed rules with
such impacts, the agency must prepare an Initial Regulatory Flexibility
Analysis that identifies those impacts and evaluates alternatives that
will minimize such impacts on small entities. OSHA finds that the
proposed rule is ``significant'' under Executive Order 12866 and
``major'' under Section 804(2) of the Small Business Regulatory
Enforcement Fairness Act of 1996. Accordingly, the Occupational Safety
and Health Administration (OSHA) has prepared this Preliminary Economic
and Regulatory Flexibility Analysis (PERFA) to support the Agency's
proposed standard for occupational exposure to tuberculosis (TB). The
following is an executive summary of that analysis. The entire test of
the PERFA can be found in the rulemaking docket as Exhibit 13.
[[Page 54215]]
The complete PERFA is composed of various chapters that describe in
detail the information summarized in the following section.
Statement of Need
TB is a communicable, potentially lethal disease caused by the
inhalation of droplet nuclei containing the bacillus Mycobacterium
tuberculosis (M. tuberculosis). Persons exposed to these bacteria can
respond in different ways: by overcoming the challenge without
developing TB, by becoming infected with TB, or by developing active TB
disease. Those who become infected harbor the infection for life, and
have a 10 percent chance of having their infection progress to active
disease at some point in their life. Those with active disease have the
signs and symptoms of TB (e.g., prolonged, productive cough; fatigue;
night sweats; weight loss) and have about an 8 percent risk of dying
from their disease.
TB has been a worldwide health problem for centuries, causing
millions of deaths worldwide. In the United States, however, there has
been a decline in the number of active TB cases over the last four
decades. Between 1953 and 1994, the number of active cases declined
from 83,304 to 24,361, an annual rate of decline of 3.6 percent over
the period as a whole (Figure VII-1). The 1988-1992 period, however,
saw the first substantial increase in the number of active cases since
1953. A number of outbreaks of this disease have occurred among workers
in health care settings, as well as other work settings, in recent
years. To add to the seriousness of the problem, some of these
outbreaks have involved the transmission of multi-drug resistant
strains of M. tuberculosis, which are often fatal. Very recently, i.e.,
after 1992, this trend has reversed, and the number of such cases
appears once again to have begun to decline. Nevertheless, TB remains a
major health problem, with 22,813 active cases reported in 1995.
Because active TB is endemic in many U.S. populations--including groups
in both urban and rural areas--workers who come into contact with
diseased individuals are at risk of contracting the disease themselves.
BILLING CODE 4510-26-P
[[Page 54216]]
[GRAPHIC] [TIFF OMITTED] TP17OC97.005
BILLING CODE 4510-26-C
[[Page 54217]]
Many occupational groups, including workers in health care, nursing
homes, homeless shelters, hospices, correctional facilities,
laboratories, physicians' offices, and other settings are at risk of
contracting TB on the job. These workers are at risk because they are
exposed in the course of their work to patients and others with active
TB disease, perform procedures that expose them to airborne
concentrations of M. tuberculosis, or serve client populations where
the incidence of active disease is unusually high.
The purpose of OSHA's standard is to reduce these risks in health
care and other work settings where active TB cases are likely to be
encountered by employees. To accomplish this goal, the proposed
standard requires those employers who are responsible for the working
conditions where such encounters occur to implement a program of
infection prevention and infection control that is designed to prevent
occupational infections in the first place, and to identify and treat
any job-related infections that do occur. The approach taken in the
proposed standard is similar to that adopted by OSHA in its 1991
bloodborne pathogens standard, which is given credit for achieving a
dramatic reduction in the number of cases of hepatitis among health
care and other workers since it was issued. OSHA predicts that, once
implemented, the proposed TB standard will have similar results,
achieving reductions on the order of 70 to 90 percent in the number of
TB infections, active cases, and directly related deaths.
This Preliminary Economic and Regulatory Flexibility Analysis
includes an introductory chapter that describes the major provisions of
the standard. The proposal would apply to occupational exposure to TB
occurring in, during, or through the provision of services by:
Hospitals.
Nursing homes.
Correctional facilities.
Immigration detainment facilities.
Law enforcement facilities.
Hospices.
Substance abuse treatment centers.
Homeless shelters.
Medical examiners' offices.
Home health care providers.
Emergency medical services.
Research and clinical laboratories handling TB.
Contract work on ventilation systems or areas of buildings
that may contain aerosolized M. tuberculosis.
Physicians performing certain high hazard procedures.
Social service workers providing services to individuals
identified as having suspected or confirmed infectious TB.
Personnel service agencies when providing workers to
covered facilities.
Attorneys visiting known or suspected infectious TB
patients.
The groups, industries, and work settings covered by the standard
have been included in its scope for specific reasons. For example,
hospitals are included because they treat patients with active TB
disease, while hospices, certain laboratories, pulmonary and certain
other physicians, medical examiners, and contract HVAC workers are
covered because employees in these settings/jobs are exposed to
aerosolized M. tuberculosis during the performance of high-hazard
procedures, such as bronchoscopies, sputum induction, autopsies, and
during work on ventilation systems that may contain TB bacteria. Other
work settings, such as homeless shelters and nursing homes, are covered
because their employees serve a client population known to have a high
incidence of TB infection. Another group of employees included within
the scope of the standard are workers who must occasionally serve
patients with active TB who are being treated in ``isolation,'' i.e., a
room or area specifically designed to contain the TB microorganism and
prevent its spread to surrounding areas. Attorneys and social workers
are typical of this group. Finally, the proposed standard covers
personnel service agencies that provide temporary, seasonal, or
``leased'' personnel to hospitals and other covered work settings.
OSHA estimates that the standard would apply to approximately
102,000 establishments and provide protection to more than 5 million
workers currently at risk of occupational exposure to TB. More than
half of these workers--almost 4 million--work in the two industries
most affected by the standard: hospitals and nursing homes. Other
covered industries with large numbers of workers are home health care,
emergency medical services, and correctional institutions.
Table VII-1 shows the number of affected establishments and the
population at risk for each covered industry. (Table VII-1 does not
include all sectors that might hypothetically be covered by the
standard. For example, a chiropractor who engaged in high hazard
procedures would be covered by the standard. However, this possibility
is sufficiently rare for this activity not to have been included in
this analysis. OSHA solicits comments on any affected job categories or
industries it may have omitted.) Because the standard requires
employers in the covered industries to make an initial determination
that will identify which job classifications, employees, and activities
within their workplace involve occupational exposure to TB, its
requirements are narrowly targeted to those workers most at risk. Thus,
for example, only approximately 57 percent of hospital workers are
potentially affected by the standard; these workers would include those
working on infectious disease floors or wards, radiology units, autopsy
suites, and in other, similarly exposed locations.
Table VII-1.--Number of Affected Establishments and Population at Risk,
by Industry
------------------------------------------------------------------------
Number of
Industry affected Population
establishments at risk
------------------------------------------------------------------------
Hospitals.................................. 5,749 2,663,996
Nursing Homes.............................. 20,254 1,200,034
Correctional Institutions.................. 2,079 268,432
Immigration Detainment..................... 12 990
Law Enforcement............................ 4,950 27,469
Hospices................................... 1,755 17,250
Homeless Shelters.......................... 10,450 85,168
Substance Abuse Treatment Centers.......... 9,730 120,115
Medical Examiners.......................... 100 2,000
Home Health Care........................... 10,921 418,538
Emergency Medical Services................. 5,099 255,200
Laboratories............................... 851 11,108
Contract HVAC.............................. 300 2,500
Social Services............................ 2,342 20,000
Physicians................................. 21,698 43,395
Pulmonary Physicians....................... 1,853 3,705
Personnel Services......................... 1,426 161,608
Attorneys.................................. 2,306 4,611
----------------------------
Total.................................. 101,875 5,306,119
------------------------------------------------------------------------
Source: U.S. Department of Labor, OSHA, Office of Regulatory Analysis.
Technological Feasibility
Chapter III of the analysis evaluates the technological feasibility
of the proposed standard for affected establishments. OSHA
preliminarily concludes that no provisions of the rule pose
technological feasibility problems for any potentially affected
entities. This is the case because the standard emphasizes
administrative controls, such as the early identification of suspected
or confirmed cases of TB and employee information and training, rather
than engineering controls. In
[[Page 54218]]
addition, the engineering controls that are required, such as AFB
isolation rooms, biological safety cabinets, and temporary AFB
isolation facilities, would be mandated only in those situations where
individuals with suspected or confirmed infectious TB are admitted and
isolated, where high hazard procedures are performed, and in situations
where individuals cannot be placed into AFB isolation rooms within five
hours of being identified as having suspected or confirmed infectious
TB. All of the engineering controls required by the standard are
currently available and in widespread use in many affected
establishments.
Benefits of the Proposed Standard
Workers employed in the work settings covered by the standard are
at significant risk of material impairment of health as a result of
exposure to M. tuberculosis on the job. These workers will be the
primary beneficiaries of the protection provided by the rule. However,
because TB is a communicable disease, many other individuals will also
benefit from the standard. Reducing the number of cases of TB among
workers who are regularly in contact both with patients and infected
members of client populations will reduce the incidence of TB
infections and active cases in these client populations (since infected
individuals spend the most time with other members of their group) and
among members of the families of exposed workers. OSHA has expressed
the benefits of the standard in terms of the numbers of TB infections,
active cases, and TB-related deaths averted by the standard. In
addition to reducing morbidity and mortality among workers, their
families, and client populations, the standard will also generate
readily quantifiable cost savings in the form of lower medical costs,
less lost production, and reduced costs for administering workers'
compensation claims and other private and social insurance system
transactions.
OSHA's estimates of the potential benefits of the standard take
into account the extent of current industry compliance with the
provisions of the proposed standard, i.e., the benefits estimates do
not include the benefits that employers in affected sectors are already
garnering as a result of their voluntary efforts to provide protections
to their TB-exposed employees. The benefits assessment presented in
Chapter IV of the economic analysis is based on OSHA's Preliminary Risk
Assessment (see that section of the preamble), which quantifies the
occupational risk of TB infection among workers in hospitals, nursing
homes, home health care work settings, and home care work settings. The
estimates of risk are based on the rate of tuberculin skin test (TST)
conversions among these populations. TST conversions are a widely used
and well-documented index of TB infection; rates of conversion among
the exposed populations are then compared with rates in unexposed or
less-exposed ``control'' populations to obtain an estimate of the
``excess'' risk associated with occupational exposure. Table VII-2
shows the results of OSHA's estimates of the risks confronting workers
in various work settings, based on statistical analyses and studies in
the literature.
Table VII-2.--Estimates of Occupational Risk Confronting Workers in Various Settings
----------------------------------------------------------------------------------------------------------------
Estimated
annual
excess rate
Setting Location and date Excess risk of TB
(percent) infection
per 1,000
workers
----------------------------------------------------------------------------------------------------------------
Hospital...................................... North Carolina Western Region--1984- 398 5.7
1985.
Hospital...................................... Washington State--1994............... 47 .68
Hospital...................................... Jackson Memorial Hospital, Miami, 795 11.8
Florida--1991.
Nursing Homes................................. Washington State--1994............... 1019 14.6
Home Health Care.............................. Washington State--1994............... 478 6.9
Home Care..................................... Washington State--1994............... 112 1.6
----------------------------------------------------------------------------------------------------------------
Source: OSHA, Preliminary Assessment of Risk.
Where risk data of good quality were available for a specific
industry, OSHA relied on that data. However, such data were available
only for the hospital, nursing home, home health care, and home care
industries. Accordingly, OSHA identified the best data to use to
characterize the occupational risk of TB infection posed to workers in
the other work settings covered by the proposed rule. After a careful
review of the available data, OSHA chose to rely on data from western
North Carolina that looked at occupational risk in a total of eight
hospitals. These data were selected because they derived from hospitals
that were relatively ``uncontrolled,'' i.e., that had not yet
implemented many of the controls that would be required by the proposed
standard. Data from the other hospitals shown in Table VII-2 were
judged to be less appropriate for the purpose of extrapolation because
Washington State hospitals are already generally in compliance with the
requirements of the proposed rule and Jackson Memorial Hospital had
recently experienced an outbreak of multi-drug resistant TB among its
patients at the time the risk data were gathered. OSHA believes that
using occupational risk data from hospitals to characterize the risk in
other occupational settings for which risk data are unavailable is
appropriate because employees in these other settings serve client
populations that have a high incidence of active TB cases, perform
high-hazard procedures, or visit hospitalized TB patients. The use of a
hospital-based risk estimate results in a lower estimate of risk than
would be the case if OSHA had used risk data from nursing homes or home
health care to characterize the risk in other settings, but a higher
risk than if OSHA had used risk data from the home care industry to do
so.
To predict the effectiveness of the proposed standard, OSHA
evaluated the reduction in occupational risk that various control
measures required by the standard can be expected to achieve.
Effectiveness is measured as the percent reduction in TST conversions
and in the TB infections, active cases, and deaths represented by those
conversions. Based on a thorough review of the available literature on
the effectiveness of control programs that have actually been
implemented in a number of hospitals, OSHA believes that the proposed
standard, once implemented, would
[[Page 54219]]
reduce TB infections among occupationally exposed hospital workers by
90 percent, and would decrease such infections in the other work
settings covered by the standard by 70 to 90 percent. OSHA also
estimated the effectiveness and medical surveillance and follow-up in
preventing infections from advancing to active cases of TB. OSHA found
that such measures reduced the probability of an infection advancing to
an active case by 35 to 47 percent, depending on the frequency of
testing.
Using these effectiveness data, taking account of the current
levels of compliance in various workplaces, and relying on the
estimates of excess risk presented in OSHA's Preliminary Risk
Assessment, OSHA predicts that the proposed standard will avert about
21,000 to 26,000 work-related TB infections per year, 1,500 to 1,750
active disease cases resulting directly from these infections, and 115
to 136 deaths directly related to the same infections. Preventing this
number of infections among workers will, in turn, prevent about 3,000
to 7,000 infections, 300 to 700 active cases, and 23 to 54 deaths among
the families, friends, clients, and contacts of these workers. In
addition, the standard will annually generate cost savings of $89 to
$116 million dollars in avoided medical costs, lost production caused
by absence from work and other factors, and insurance administration
costs. Table VII-3 shows the benefits of the proposed standard.
Table VII-3.--Summary of Benefits Associated With the Proposed Standard
--------------------------------------------------------------------------------------------------------------------------------------------------------
Type of benefit Work-related Transmissions from work-related sources Total number averted
--------------------------------------------------------------------------------------------------------------------------------------------------------
Infections Avoided........... 21,380-25,769............................ 2,954-6,978.............................. 24,334-32,747.
Active Cases Avoided......... 1,477-1,744.............................. 295-698.................................. 1,772-2,442.
Deaths Avoided............... 115-136.................................. 23-54.................................... 138-190.
Cost Savings................. $80,721,000-$95,393,000.................. $8,614,000-$20,381,000................... $89,335,000-$115,774,000.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source: Office of Regulatory Analysis, OSHA, DOL.
Chapter V of the economic analysis projects the costs employers in
the various industries covered by the standard are estimated to incur
to achieve compliance with the rule's requirements. OSHA estimated
costs for each covered industry and for each provision of the standard.
These costs take account of the baseline levels of compliance
prevailing in each industry at the present time and are presented as
annualized costs discounted at 7 percent. Annualized costs are the sum
of annualized initial costs and recurring annual costs. For example, a
temporary AFB isolation room costing $4,095 with annual maintenance
costs of $50 would have annualized costs of $633 ($583 + $50).
The total estimated costs of compliance for the standard as a whole
are $245 million per year. The most costly provisions of the standard
are those requiring medical surveillance and training for
occupationally exposed employees. Together, these two provisions
account for 60 percent of the costs of compliance. The two industries
projected to incur the highest costs are hospitals and nursing homes.
Together, the costs incurred by these two industries are estimated to
be $138 million per year. Tables VII-4 and VII-5 summarize the
annualized costs of compliance, by provision and industry,
respectively.
Table VII-4.--Total Annualized Costs, by Provision
------------------------------------------------------------------------
Total
Provision annualized
cost
------------------------------------------------------------------------
Exposure Control........................................ $12,858,183
Work Practice Controls.................................. 9,740,559
Transfers........................................... 9,740,559
Engineering Controls.................................... 22,529,248
AFB Isolation Rooms................................. 7,547,912
Temporary AFB Isolation............................. 10,792,678
Laboratories........................................ 780,270
Autopsies........................................... 2,903,077
Daily Testing of Negative Pressure.................. 505,310
Respiratory Protection.................................. 45,771,276
Respirators......................................... 32,225,228
Respirator Program.................................. 1,670,677
Fit Testing......................................... 8,905,821
Evaluation of Program............................... 2,969,549
Medical Surveillance.................................... 94,901,455
Medical History/Physical Exam....................... 62,974,255
Tuberculin Skin Testing (TST)....................... 21,907,252
Medical Management/Follow-up........................ 4,773,377
Medical Removal..................................... 5,246,570
Communication of Hazards................................ 52,268,172
Signs and Labels.................................... 58,284
Training............................................ 52,209,888
Recordkeeping........................................... 7,228,533
Engineering Control Maintenance..................... 20,052
Medical............................................. 6,785,014
Training............................................ 423,467
---------------
[[Page 54220]]
Total........................................... 245,297,426
------------------------------------------------------------------------
Source: U.S. Department of Labor, OSHA, Office of Regulatory Analysis.
Table VII-5.--Summary of Compliance Costs, by Industry
------------------------------------------------------------------------
Total
Provision annualized
cost
------------------------------------------------------------------------
Hospitals............................................... $61,819,637
Nursing Homes........................................... 76,500,314
Correctional Institutions............................... 20,187,666
Immigration Detainment.................................. 145,378
Law Enforcement......................................... 6,708,174
Hospices................................................ 2,237,959
Homeless Shelters....................................... 11,287,278
Substance Abuse Treatment Centers....................... 12,751,545
Medical Examiners....................................... 557,811
Home Health Care........................................ 16,448,605
Emergency Medical Services.............................. 4,981,780
Laboratories............................................ 1,696,383
Contract HVAC........................................... 396,197
Social Services......................................... 3,063,444
Physicians.............................................. 5,663,949
Pulmonary Physicians.................................... 930,775
Personnel Services...................................... 18,363,135
Attorneys............................................... 1,557,398
---------------
Total............................................... 245,297,426
------------------------------------------------------------------------
Source: U.S. Department of Labor, OSHA, Office of Regulatory Analysis.
Chapter VI assesses the economic impacts of the proposed standard
on the industries affected by the proposed standard and also analyzes
the impacts on the small businesses within each of these industries.
OSHA preliminarily concludes that the standard is economically feasible
for affected firms. On average, annualized compliance costs for all
entities amount only to 0.06 percent of revenues and only 1.8 percent
of profits. For all industries, costs as a percentage of revenues are
less than 1 percent. For two industries, costs as a percentage of
profits exceed 5 percent; these industries are substance abuse
treatment centers and personnel services. OSHA does not believe,
however, that these profit impacts will actually be incurred by
facilities in these two sectors. Only 18.5 percent of substance abuse
treatment centers operate on a for-profit basis. If substance abuse
treatment centers can increase their revenues by as little as 0.34
percent, they can completely offset their compliance costs. The revenue
increases or reductions in services needed to achieve cost passthrough
are not expected to represent significant impacts for these facilities.
The situation for personnel service firms is similar; these firms would
have to increase the prices charged to their customers by as little as
0.56 percent to completely offset the costs of compliance. It is likely
that these agencies will be able to pass such a small increase in costs
through to their customers, i.e., to facilities purchasing personnel
services. Table VII-6 shows compliance costs as a percentage of
revenues, by industry.
Table VII-6.--Screening Analysis to Identify Potential Economic Impacts on Affected Entities
----------------------------------------------------------------------------------------------------------------
Percent of for-
Number of profit Cost as a
Industry affected establishments percentage
establishments in industry of revenues
----------------------------------------------------------------------------------------------------------------
Hospitals.......................................................... 5,749 15.5 0.02
Nursing Homes...................................................... 20,254 71.4 0.16
Correctional Institutions.......................................... 2,079 0.0 0.10
Immigration Detainment............................................. 12 0.0 0.16
Law Enforcement.................................................... 4,950 0.0 0.03
Hospices........................................................... 1,755 12.0 0.09
Homeless Shelters.................................................. 10,450 0.0 0.64
Substance Abuse Treatment Centers.................................. 9,730 18.5 0.34
Medical Examiners.................................................. 100 0.0 0.28
Home Health Care................................................... 10,921 40.6 0.11
Emergency Medical Services......................................... 5,099 14.5 0.11
[[Page 54221]]
Laboratories....................................................... 851 100.0 0.13
Contract HVAC...................................................... 300 100.0 0.17
Social Services.................................................... 2,342 0.0 0.27
Physicians......................................................... 21,698 95.0 0.03
Pulmonary Physicians............................................... 1,853 95.0 0.06
Personnel Services................................................. 1,426 100.0 0.56
Attorneys.......................................................... 2,306 89.8 0.10
--------------------------------------------
Total.......................................................... 101,875 48.7 0.06
----------------------------------------------------------------------------------------------------------------
Source: U.S. Department of Labor, OSHA, Office of Regulatory Analysis.
OSHA has preliminarily concluded that the proposed standard will
have a significant impact on a substantial number of small entities and
has therefore, as required by the Regulatory Flexibility Act Amendments
of 1996, conducted an Initial Regulatory Flexibility Analysis (IRFA).
This analysis has identified significant impacts on the small entity
portion of the hospital, nursing home, correctional institution,
homeless shelter, substance abuse treatment center, contract HVAC, and
personnel services industries.
For the purposes of this analysis, OSHA defines small for-profit
entities using the Small Business Administration's (SBA's) Table of
Size Standards. For businesses affected by the proposed standard, the
SBA classifies entities with annual revenues of less than $5 million as
small for all industries, with the exception of contract HVAC firms,
for which entities with less than $7 million in annual revenues are
classified as small.
A small not-for-profit entity is defined as any nonprofit
enterprise that is independently owned and operated and is not dominant
in its field. Based on this definition, all not-for-profit entities
affected by the proposed standard are considered small.
Many of the affected industries consist almost entirely of public
sector facilities, such as correctional facilities, immigration
detainment facilities, law enforcement facilities, medical examiners'
offices, and social service organizations. Several other affected
industries include some government-owned facilities, such as hospitals,
nursing homes, and emergency medical services. Under the Regulatory
Flexibility Act, ``small governmental jurisdiction'' refers to
governments of cities, counties, towns, townships, villages, school
districts, or special districts with populations of less than 50,000.
For most of the affected industries, information on the number of such
entities was not readily available. Where data were unavailable, the
number of small publicly-owned entities was estimated based on the
average number of people served per employee in each industry, from
which OSHA estimated the average employment size of establishments
serving populations of less than 50,000. These entities are considered
small for the purposes of this analysis. OSHA requests information on
size standards for public-sector entities.
OSHA requests comment on these definitions and estimates of the
number of small entities. The complete IRFA is presented in Chapter VI
of the economic analysis, and is also presented here.
Initial Regulatory Flexibility Analysis
The Regulatory Flexibility Act, as amended in 1996, requires that
an Initial Regulatory Flexibility Analysis contain the following
elements:
(1) A description of the reasons why action by the agency is being
considered;
(2) A succinct statement of the objectives of, and legal basis for,
the proposed rule;
(3) A description of, and, where feasible, an estimate of the
number of small entities to which the proposed rule will apply;
(4) A description of the projected reporting, recordkeeping and
other compliance requirements of the proposed rule, including an
estimate of the classes of small entities that will be subject to the
requirement and the type of professional skills necessary for
preparation of the report or record; and
(5) An identification, to the extent practicable, of all relevant
Federal rules that may duplicate, overlap or conflict with the proposed
rule.
In addition, a regulatory flexibility analysis must contain a
description of any significant alternatives to the proposed rule that
accomplish the stated objectives of applicable statutes (in this case
the OSH Act) and that minimize any significant economic impact of the
proposed rule on small entities.3 This section of the
analysis closes with a review of the recommendations of the SBREFA
Panel concerning this proposed rule and discusses how OSHA has
responded to these recommendations.
---------------------------------------------------------------------------
\3\ The Regulatory Flexibility Act states that a Regulatory
Flexibility Analysis need not contain all of the above elements in
toto if these elements are presented elsewhere in the documentation
and analysis of the rule. The Regulatory Flexibility Analysis
should, however, summarize where these elements can be found
elsewhere in the rulemaking record.
---------------------------------------------------------------------------
Reasons for the Proposed Rule
From 1985 to 1994, the number of active TB cases in the United
States increased by 9.4 percent, reversing a 30-year downward trend.
Although the number of cases reported to the CDC has declined over the
past few years, TB remains a serious problem in the United States. In
1994, 24,361 active TB cases were reported to the Centers for Disease
Control and Prevention (CDC), and TB was reported to have caused 1,590
deaths in that year alone (Ex. 7-283).
Transmission of M. tuberculosis is a recognized risk in several
work settings. A number of outbreaks of this dreaded disease have
occurred among workers in health care settings, as well as other work
settings, in recent years. To add to the seriousness of the problem,
some of these outbreaks have involved the transmission of multidrug-
resistant strains of M. tuberculosis, a form of the disease that is
often fatal.
Objectives of the Proposed Rule
The objective of this proposal is to reduce the risk of
occupational exposure to M. tuberculosis in exposed working populations
through the use of engineering controls, work practice controls,
respiratory protection, medical
[[Page 54222]]
surveillance, training, signs and labels, and recordkeeping.
Implementation of these measures has been shown to minimize or
eliminate occupational exposure to M. tuberculosis, and thus to reduce
the risk of TB infection among workers. The legal authority for this
proposed standard is the Occupational Safety and Health Act, 29 U.S.C.
655(b).
Description of the Number of Small Entities
The proposed rule would cover 80,400 establishments operated by
67,116 small entities, as defined above. Of the 67,116 small entities,
about 49 percent (32,605 entities) are for-profit small entities, 20
percent (13,622 entities) are publicly-owned, and 31 percent (20,889
entities) are not-for-profit. About 79 percent of the total number of
affected establishments are operated by small entities. The proposed
rule covers 48,804 establishments operated by 48,044 very small
entities, defined as entities of all kinds employing fewer than 20
workers. Almost 48 percent of the affected establishments are operated
by very small entities.
Description of Proposed Reporting, Recordkeeping and Other Compliance
Requirements
Avoiding a One-Size-Fits-All Standard. Occupational TB occurs in a
wide variety of settings, which means that the risk varies
substantially, and control measures differ, from one facility to
another. OSHA's proposed TB standard has been tailored to recognize
these differences. With respect to the background risk of exposure, the
OSHA standard distinguishes between work settings in counties that have
had no cases of TB in one of the past two years and fewer than 6 cases
in the other of the past two years, work settings in counties with one
or more cases of TB in both of the past two years or that have had 6 or
more cases of TB in one of the past two years, and work settings that
have encountered 6 or more cases of TB in the past 12 months. In
addition, the OSHA standard treats different types of exposure to TB
differently. For example, the standard has different requirements for
employers who own facilities that treat TB patients, employers whose
client populations have high TB rates, employers whose employees (such
as attorneys and social service providers) visit patients who have been
identified as having suspected or confirmed cases of TB, employers
whose employees engage in various high hazard procedures, employers
whose employees provide maintenance for ventilation systems serving
confirmed or suspected TB patients, and employers who provide personnel
to treat patients in their own homes. In part because of these many
distinctions, the SBREFA Panel found that the regulation was difficult
for many employers to understand (Ex. 12). To make the tailoring of the
standard to specific situations easier to see, OSHA has developed
tables showing which provisions of the standard are most likely to
apply to employers in different circumstances and in various affected
sectors (see the Scope paragraph discussion in Section X of the
Preamble, ``Summary and Explanation''). In addition, OSHA intends to
provide extensive outreach when the standard is published in final
form. OSHA solicits comments on other ways to avoid a ``one-size-fits-
all'' standard while at the same time making the standard easier to
follow. For example, would developing a flow chart and/or expert system
that asks employers a series of questions and then directs employers to
applicable requirements be an aid to affected small entities?
Description of the Proposed Standard. The proposed rule would
require that employers develop and implement exposure control plans;
institute work practice and engineering controls; provide respiratory
protection in various situations; provide medical surveillance (e.g.,
tuberculin skin testing, medical histories, medical management, medical
follow-up, medical removal); and communicate hazards through the use of
signs, labels, and training. These proposed requirements are discussed
in greater detail in the Introduction (Chapter I) of this analysis.
The proposed standard would also require that employers establish
and maintain medical, training, illness/injury, and engineering control
maintenance and performance monitoring records. All establishments
affected by the proposed rule would be affected by these proposed
requirements. However, only establishments with engineering controls
would be required to maintain records of the maintenance and monitoring
of engineering controls.
In estimating the cost of establishing and maintaining medical
records, OSHA used the wage rate of a clerical worker with some
knowledge of medical recordkeeping as the base wage. However, the
knowledge required to perform such duties can be acquired by most
clerical workers with little effort. All recordkeeping requirements
included in the proposed rule could therefore be performed by the
existing staff in any of the covered industries. A detailed description
of the proposed requirements appears in the Introduction and in the
Costs of Compliance chapters of this analysis.
Relevant Federal Rules That May Duplicate, Overlap, or Conflict With
the Proposed Rule
On October 28, 1994, the Centers for Disease Control and Prevention
(CDC) of the U.S. Department of Health and Human Services published
``Guidelines for Preventing the Transmission of Mycobacterium
tuberculosis in Health-Care Facilities,'' which recommends that
facilities adopt many of the requirements included in this proposed
standard. CDC has also published guidelines for the prevention of
transmission of TB in homeless shelters, long-term care facilities for
the elderly, and correctional institutions. OSHA has consulted with CDC
in developing the proposed standard, and the basic elements of the
standard correspond to the basic elements in the CDC guidelines.
However, the CDC publication is only recommendatory and is therefore
not enforceable. OSHA's studies (see chapters IV and V) show that few
facilities are following all elements of these guidelines. Further,
many portions of the CDC guidelines are written in language that does
not lend itself to enforcement even if the guidelines were made
mandatory. For example, portions of the CDC guidelines for health care
facilities suggest that the employer ``consider'' adopting certain
controls. A fuller discussion of the similarities and differences
between OSHA's proposed rule and the CDC's recommendations is provided
in Section III of the Preamble, which describes the events leading to
the proposed standard. Although the U.S. Public Health Service has
overall responsibility for the control of TB in the U.S. population,
OSHA is the only agency specifically mandated to address the problem of
TB transmission in occupational settings.
The Health Care Financing Administration (HCFA) of the U.S.
Department of Health and Human Services requires that facilities
undergo an initial accreditation inspection prior to receiving Medicare
and Medicaid funding. Such facilities include hospitals, nursing homes
and other long-term care facilities, and clinical laboratories.
Hospitals are reinspected annually, nursing homes every 15 months, and
laboratories every two years. One of the requirements of such
accreditation is the implementation of an infection control program.
However, unlike the OSHA proposed rule, HCFA's requirements do not
specify the elements that must be included in such
[[Page 54223]]
a program. HCFA may cite facilities with poor results for specific
program deficiencies but does not have the authority to cite facilities
for failing to include specific elements in their infection control
programs, unless those program elements are specifically required by an
OSHA standard. This means that in the absence of an OSHA TB standard,
HCFA could not require implementation of specific controls. The
proposed rule does not in any way conflict with HCFA requirements.
Further, the existing HCFA requirements have not ensured that health
care facilities adopt the elements of an effective infection control
and have not prevented outbreaks of TB in this workforce.
One small entity representative to the SBREFA Panel suggested that
the OSHA regulation might conflict with state and local requirements
for skin testing and for tracing contacts of active cases of TB (Ex.
12). OSHA has considered this suggestion and believes there is no
conflict. Some states do have rules covering TB testing and contact
tracing, but most states do not. In 1993, only 18 states had
requirements for TB screening of employees in medical facilities, and
only 23 states had testing requirements for nursing home employees.
Further, these requirements are sometimes not as stringent as those
OSHA is proposing; for example, some states require only an initial
skin test. Although 49 states require the investigation of reported
cases of TB, only 29 states require contact tracing by health
departments. In states where local health departments provide contact
tracing, such contact tracing would constitute compliance with OSHA's
requirements for contact tracing by employers. Employers merely need to
assure that contact tracing takes place; they need not do the contact
tracing themselves if others are available to do this job for them.
Thus, there is no conflict between the OSHA standard and existing state
requirements, nor do existing state laws obviate the need for a
standard that requires TB testing of exposed employees and the
investigation of reported TB exposures. However, OSHA solicits comment
on the interaction of state rules regarding testing and tracing and the
proposed standard.
One small entity representative was concerned with how medical
removal protection and worker compensation programs would interact (Ex.
12). Medical removal protection requires that workers receive full
salaries, full benefits, and no loss of job position or seniority while
the employee is unable to work, or unable to work at his/her usual
position, as a result of incurring an occupational case of TB. The
purpose of medical removal protection is to assure that workers provide
timely and accurate information to their employers concerning their
medical symptoms. In the absence of medical removal protection, workers
have financial and job security incentives to avoid reporting symptoms.
OSHA counts any payments workers receive from workers' compensation
toward the goal of assuring medical removal protection; that is,
employers may deduct from the amount they pay out to the worker any
monies paid to the ill worker by workers' compensation. Workers'
compensation is not an adequate substitute for medical removal
protection because workers' compensation does not fully replace lost
wages and provides no guarantee of maintenance of seniority, job
security, current position, or non-wage benefits. Medical removal
protection requires the employer to provide any of these elements that
are not a part of workers' compensation. Thus, the employer of a worker
already receiving workers' compensation would need to provide an
additional salary increment in order to restore the employee's full
salary and would need to provide the worker his or her full non-wage
benefits.
One small entity representative expressed concern over a possible
conflict between the proposed rule and Federal Confidentiality
Regulations covering chemically abusive or dependent clients
participating in licensed and federally-funded programs [Ex. 12]. These
regulations prohibit disclosing information regarding the
identification of a patient as a substance abuser without the patient's
consent. This representative noted that, without patient consent, a
disclosure may be made only to medical personnel to meet a situation
that has been declared a medical emergency by the Surgeon General. This
small entity representative was referring to Public Health regulations:
Confidentiality of Alcohol and Drug Abuse Patient Records, 42 CFR 2,
and a similar state statute: Confidentiality of Records, Minnesota
Statute 254A.09. Both the Federal Confidentiality Regulations and the
state statute cover records that would identify a patient as an
alcoholic or drug abuser or concern his or her prognosis, diagnosis,
treatment, attendance, status or physical whereabouts. No requirements
of the standard would require the disclosure of records of this kind.
These are not the kinds of records that are relevant to determining
whether an individual has suspect or confirmed infectious TB. In
addition, a medical referral for the client who is exhibiting signs and
symptoms of TB can be made without revealing any of the prohibited
confidential information. Moreover, in the case of an exposure
incident, the identity of the individual with suspected or confirmed
infectious TB need not be told to employees. Records maintained by
employers on their employees are not covered by the regulations or
statute, but would be subject to the same confidentiality requirements
that govern all medical records. The identification and notification
requirements in the proposed TB standard are the minimum necessary to
prevent transmission of TB to employees. The contagious nature of the
disease mandates early detection and early monitoring of individuals
who have had an exposure incident.
One small entity representative to the SBREFA Panel expressed
concern over possible interactions between the proposed standard and
the Family and Medical Leave Act (FMLA) (Ex. 12). The Family and
Medical Leave Act does not provide for leave with pay, and does not
guarantee the continuation of any benefits other than health insurance.
Further, the Family and Medical Leave Act covers a more limited
timeframe (12 weeks) than the proposed standard's medical removal
protection provisions (18 months). Thus, the only overlap between the
proposed standard and the FMLA would occur in the area of health
insurance benefits in the first 12 weeks of the worker's absence from
work. Since the standard would specifically allow the employer to
deduct from medical removal protection benefits any benefits paid to
the worker from other sources, employers would not pay for the same
benefits twice.
One small entity representative felt that the Americans with
Disabilities Act (ADA) may offer protection to the ``worker who becomes
ill as a result of an occupational exposure or who cannot work because
of an inability to wear a PR [respirator].'' (Ex. 12) The ADA prohibits
employers of 15 or more employees from discriminating, because of the
disability, against a qualified individual with a disability with
regard to terms, conditions and privileges of employment. An employer
must provide reasonable accommodation for known physical or mental
limitations for a qualified individual with a disability, unless
accommodation can be shown to impose undue hardship on the employer.
OSHA representatives noted that there is no conflict between an OSHA
standard and the ADA requirements prohibiting discrimination. The ADA
says that:
[[Page 54224]]
Nothing in this Act shall be construed to invalidate or limit
the remedies, rights and procedures of any Federal law * * * that
provides greater or equal protection for the rights of individuals
with disabilities that are afforded by this Act. 42 U.S.C.A.
12201(b).
Further, the ADA would not provide the same protections as medical
removal protection. In order for an employee to take advantage of the
provisions of the ADA, certain conditions must be met. For example, the
employee must work for a covered employer and be a qualified individual
with a disability, i.e., one who can perform his or her job with or
without reasonable accommodation. Thus, while the ADA may offer some
protection to an employee who has or is suspected of having infectious
TB or who cannot work because he or she cannot wear a respirator, the
protection proposed to be provided by the OSHA standard for TB is more
comprehensive and will lead to greater participation in the entire
medical surveillance program. The OSHA proposed standard, in paragraph
(g)(5)(ii), would provide to the employee with suspected or confirmed
infectious TB:
* * * his or her total normal earnings, seniority, and all other
employee rights and benefits, including the employee's right to his
or her former job status * * * until the employee is determined to
be noninfectious or for a maximum of 18 months, whichever comes
first.
For each employee who must be removed for his or her job because he or
she cannot wear a respirator (paragraph (g)(5)(iii)), the employer is
required to:
transfer the employee to comparable work for which the employee is
qualified or can be trained in a short period (up to 6 months),
where the use of respiratory protection is not required [and] * * *
maintain the total normal earnings, seniority, and all other
employee rights and benefits. If there is no such work available,
the employer shall maintain the employee's total normal earnings,
seniority, and all other employee rights and benefits until such
work becomes available or for a maximum of 18 months, whichever
comes first.
OSHA's MRP provisions provide each employee, who must be medically
removed, with the level of protection that is needed to assure that the
employee promptly reports his or her symptoms of TB (which makes the
workplace safer for all employees) and reports his or her difficulty
with wearing a respirator (which makes the workplace safer for that
employee).
Significant Alternatives to the Rule Considered by OSHA
This section first considers alternatives that OSHA was urged to
consider by the SBREFA Panel and then turns to other alternatives
considered by the Agency.
Alternatives Suggested by SBREFA Panel Members
Small entity representatives and SBREFA Panel members suggested a
wide variety of possible clarifications and alternatives to the
regulation. In response to these suggestions, OSHA has made a number of
changes to the regulation, clarified the meaning of many sections of
the rule, provided additional analysis, and added tables to the
Preamble designed to clarify the requirements of the rule in various
situations. A full discussion of OSHA's responses to all of the SBREFA
Panel recommendations is given in the next section. This section only
presents alternative approaches to the proposed rule and a discussion
of the extent to which OSHA has adopted these alternative approaches.
OSHA welcomes comments on these and other alternatives and on ways OSHA
could adopt additional aspects of these alternative approaches and
still meet the requirements of the OSH Act, particularly that Act's
requirement to control significant risk to the extent feasible.
Less Stringent Trigger Mechanisms for the More Burdensome Portions of
the Standard, Including Raising the Zero-Case Per County Per Year
Trigger
OSHA has re-examined each provision of the proposed standard to
ensure that it is necessary and appropriate to reduce risk. In the
draft of the proposal reviewed by the Panel, OSHA required that a
facility would only be eligible for the reduced TB control program
requirements of Appendix A if the facility did not treat TB patients
and if there had been no cases of TB in the county or the facility in
the previous year. In its review, OSHA found that applying the
standard's Appendix A requirements to facilities in counties with no TB
cases in one of the last two years and fewer than 6 TB cases in the
other of the last two years would not substantially increase the risk
to employees in facilities located in such counties. This change from
the trigger OSHA originally considered increases the number of counties
qualifying for the Appendix A program from 43 percent to 55 percent of
all U.S. counties.
Consider Allowing Portability of Training
The draft proposal reviewed by the SBREFA Panel required that all
new employees be provided complete training. OSHA has examined its
training provisions and decided that the non-site-specific components
of training, such as training in the difference between tuberculosis
infection and disease, can be transferred between employers without
reducing the protection such training affords employees.
Do Not Require Annual Retraining
The draft proposal reviewed by the SBREFA Panel required annual
retraining of all employees. OSHA believes that some method of assuring
continuing competency is necessary, and that one-time training will not
provide such assurance. However, the proposal now would allow employers
to develop methods of assuring the competency of their employees, such
as asking them questions about procedures, controls, etc., as an
alternative to retraining. This change in the regulation will result in
cost savings of $20 million per year.
Cooperative Initiatives, Such as Expanding OSHA's Current Cooperative
Initiative With JCAHO
Some Panel members felt that cooperative initiatives could
substitute for regulation in some areas. As noted above, however, in
the absence of an OSHA standard, HCFA (and accrediting associations
working with HCFA, such as JCAHO) does not have the authority to
enforce specific infection control requirements. As a result, a
cooperative initiative alone would leave employees exposed to TB in
hospitals, who account for 13 percent of the active cases of TB
projected to be prevented by the standard, without any new initiative
designed to prevent these active cases of TB. If this approach were
extended to nursing homes, and all nursing homes chose to be
accredited, then 70 percent of the active cases of TB projected to be
prevented by the standard would be denied coverage. Thus, OSHA does not
feel that cooperative initiatives, even with accrediting organizations,
can substitute for regulation.
Others suggested that OSHA could turn over enforcement of any TB
regulation to HCFA, JCAHO or another accrediting or standards
organization. In the eyes of its proponents, the suggestion that others
could enforce OSHA's regulation has several major advantages. First, it
would assure regular and more frequent inspections at health care
facilities and nursing homes than OSHA alone could provide. Second, it
would require health care facilities and nursing homes to deal only
with a single inspection for infection control procedures, rather than
[[Page 54225]]
inspections by two different federal agencies. Third, these
organizations may have greater penalty powers than OSHA, in that denial
of HCFA acceptance or of accreditation can result in a health care
facility losing significant funding or even being required to close.
For several reasons, providing exclusive HCFA enforcement of OSHA's
TB requirements is an unsound approach. First, OSHA inspectors already
inspect health care facilities, just as they inspect any other facility
covered by the OSH Act, for possible violations of any OSHA
requirement, e.g., safety as well as health requirements. The need for
these OSHA inspections would not change even if HCFA or accrediting
agencies enforced OSHA's TB requirements. Second, OSHA does not believe
that it is legally appropriate under the OSH Act to tell its inspectors
that, when they inspect health care facilities, they must ignore
violations of the Agency's occupational exposure to TB requirements.
Third, OSHA also cannot legally ignore employee complaints relating to
occupational exposure to TB. For all of these reasons, OSHA believes
that exclusive enforcement of the rule by HCFA or by agencies, such as
JCAHO, that are authorized to provide accreditation, is not an
appropriate or legally defensible approach.
However, OSHA does favor expanding its cooperative agreements, such
as the current agreement with JCAHO, in any ways that both agencies
agree would be beneficial, and OSHA is currently pursuing this option.
On August 5, 1996, OSHA and JCAHO announced a 3-year partnership to
promote health and safety for healthcare workers. This partnership will
help health care facilities to meet accreditation expectations and OSHA
compliance requirements. The initiatives of this partnership will
include cataloging and evaluating duplicative compliance activities;
undertaking cross-education and training of JCAHO and OSHA staff on
corresponding requirements that relate to the management of worker
safety and health; and developing a series of collaborative
publications and user education programs.
A Federal-State Government Public Health Partnership to Develop
Guidelines in Various Industry Sectors
The CDC is already charged with developing guidelines for the
control of TB, and has already issued guidelines for correctional
institutions, laboratories, health care facilities, long-term care
facilities for the elderly, and homeless shelters. In fact, OSHA has
made extensive use of these guidelines in developing its proposed
occupational exposure to TB standard. OSHA feels that the CDC
guidelines alone have not served adequately to protect TB-exposed
workers, however. OSHA research indicates that the CDC guidelines are
not being followed in most facilities, and believes that this is the
reason that occupational exposure to TB remains such a serious problem
in this country. In Chapter VII of the analysis, OSHA shows that these
guidelines are not being followed and explains why many employers have
little economic incentive to implement these guidelines.
Performance Standards Developed With the Assistance of Federal, State,
and Local Government, and Labor and Industry
OSHA feels that its standard is a performance oriented standard
that has benefited from both CDC's expertise and from many stakeholder
meetings (which include representatives of other federal, state and
local government agencies, labor, and industry) and the SBREFA Panel
Process.
OSHA's proposed standard is performance oriented in a variety of
ways. For example, OSHA does not specify procedures by which facilities
must achieve AFB isolation, but instead allows any workable design.
Similarly, OSHA sets performance criteria for respirators, but does not
specify the types of respirators that must be used. OSHA does specify
procedures for identification of suspect cases, but allows any method
that assures that persons with the appropriate symptoms are identified
as suspect cases. However, OSHA did not consider it appropriate to
specify performance in terms of rates of TB cases or TB skin test
conversions. Such an approach is not preventive, in that application of
proper procedures would only occur after TB infection had occurred.
Furthermore, most smaller facilities do not have enough TST conversions
for statistically meaningful trends to be established. OSHA requests
comments on this issue.
Some proponents of this approach feel that OSHA's proposed standard
may not reflect the best ideas for controlling occupational exposure to
TB and argue that stakeholder meetings would be a useful way of
developing a better approach. OSHA held five stakeholder meetings
involving representatives from more than thirty interested
organizations. Furthermore, the CDC has made use of the best expertise
in the country in developing its guidelines, and OSHA has adopted most
elements of these guidelines and will hold public hearings on the
standard at which interested parties can present their views. OSHA
welcomes comments about alternative approaches to reducing occupational
exposure to TB, particularly suggestions concerning more performance
oriented approaches, but feels that this proposal is the result of an
extensive review of the literature and of input from stakeholders on
the available prevention and control methods and should be issued as a
proposal at this time to prompt further discussion and exchange of
information. OSHA is particularly interested in alternative methods of
identifying suspected cases of TB and in whether the proposed
requirements would preclude or impede programs that employers have
found to be effective.
Separate Approaches for Health and Non-Health Industries The Approach
for Health Industries Should Be Keyed to Existing Industry Standards
and That for Non-Health Industries to Guidelines
This suggested alternative incorporates several concepts. First, it
assumes that the health and non-health care sectors should be given
separate treatment because of differences in existing regulations and
expertise. OSHA agrees that sectors that differ in relevant ways should
be given different treatment, and the standard therefore has provided
for different approaches to different sectors. For example, OSHA's
standard does treat facilities that treat TB patients differently from
the way it treats those that transfer TB patients out of their
facilities, and treats employers whose employees are routinely in
contact with client populations with high rates of infectious TB (such
as homeless shelters and drug abuse treatment centers) differently from
employers whose employees only come into contact with infectious TB
cases on an occasional basis (such as attorneys and social workers).
Second, this alternative posits that the health care sector is
already subject to an extensive regulatory system with respect to
occupational exposure to TB. Although some states have laws on contact
tracing and skin testing, and HCFA inspects infection control systems
in hospitals and long-term care facilities for the elderly, there are
no existing enforceable standards aimed specifically at occupational
exposure to TB. Thus OSHA's proposed provisions with respect to
preventive measures have no equivalent in existing regulations, and
only a limited number of states require skin testing of the kind OSHA's
proposed standard requires. OSHA (and CDC) believes that these
[[Page 54226]]
provisions are essential to any program to control occupational
exposure to TB. Third, proponents of this alternative believe that the
non-health care sectors, particularly those engaged in charitable work
such as homeless shelters, are better approached through guidelines
than regulations. OSHA believes that there is relatively little need to
develop guidelines for non-healthcare sectors, such as correctional
institutions and homeless shelters, because such guidelines already
exist and have not been implemented in many, if not most, facilities.
Some proponents of this approach believe that the failure of non-health
care sectors to implement existing guidelines is due to the absence of
outreach and information. OSHA is not substituting a system of
regulation for a system of outreach. OSHA intends to continue a program
of outreach on occupational TB, and hopes that facilities in all
sectors will adopt appropriate policies before the regulation is
finalized. However, given that even in the relatively knowledgeable
health care sector, implementation of the CDC guidelines has been
limited, it is unlikely that outreach alone can assure the full
implementation of suitable measures for control of occupational
exposure to TB.
Different Levels of Requirements for Different Industries, Depending on
Their Expertise, Resources, and Risk
OSHA's proposed standard recognizes three levels of risk and
provides separate treatment for employers engaged in different kinds of
activities, where those differences are relevant to the purposes of the
standard. This subject is discussed in the next sections. Such
tailoring, however, must be consistent with the mandate of the
Occupational Safety and Health Act to reduce significant risk to the
full extent feasible. OSHA has preliminarily found all of the
standard's provisions to be technologically and economically feasible,
within the meaning of the Act, for facilities in all affected
industries. (The special potential problems of homeless shelters and
substance abuse treatment centers are discussed further below.) The
statutory requirement to eliminate significant risk to the extent
feasible means that if inadequate resources and expertise would make
any provision of the proposed standard infeasible, then OSHA would have
to consider alternative approaches. However, it also means that the
resources and expertise that are feasible for an employer to acquire
must be employed if they will reduce significant risk.
Separate Standards for Each Affected Industry
Proponents of this alternative had two goals: first, to assure that
OSHA gave full consideration to the circumstances of each affected
industry, and second, to make the standard easier to follow for
affected small entities. With respect to the first goal, OSHA has
recognized a wide variety of distinctions in risk of exposure and
practice among affected employers. Some of these differences follow
industry lines. Accordingly, the proposed standard includes special
provisions for laboratories and home health care providers. However,
most of the relevant differences among employers do not strictly follow
industry lines, and attempts to write separate standards for different
industries would not significantly reduce the complexity of the
regulation. For example, all industries need to realize that different
requirements are applicable for each of three types of risk of
exposure. Similarly, the applicability of certain requirements depends
on whether TB patients are treated onsite and on whether certain
hazardous procedures are performed. While, for example, the typical
nursing home would not treat TB patients or perform high hazard
procedures on site, some might, and thus these provisions would need to
be included in an industry standard written for nursing homes. OSHA's
proposed standard carefully distinguishes a variety of activities that
may occur in different industries and has different requirements for
each activity. Although this makes the standard somewhat more complex,
this approach is essential to avoid a ``one size fits all'' standard.
In addition, as presented in the discussion of the scope in the Summary
and Explanation of the Preamble, OSHA has developed charts showing the
requirements of the proposed standard that are applicable to each
industry. OSHA welcomes any suggestions on ways to make the standard
easier to understand, or on ways to adapt the standard to the situation
of specific industries while reducing significant risk.
Revise the Proposed Standard for Consistency With CDC Guidelines
The issue of how the CDC Guidelines fit into a regulatory scheme to
prevent or reduce occupational exposure to TB has been considered by
OSHA and other reviewers. OSHA's view is embodied in the proposed
standard, in which the Agency has attempted to translate the CDC's
recommendations into enforceable regulatory language that can be
applied to a variety of occupational settings where the risk of
transmission of TB is significant. The Agency believes that, in
addition to the basic difference between a ``guideline'' and a
``regulation,'' there are only three general areas where the proposed
standard differs substantially from the CDC Guidelines for health care
facilities: the use of site-specific risk assessment, the frequency of
skin testing in certain situations, and the required use of respiratory
protection around unmasked individuals with suspected or confirmed
infectious TB. Several small entity representatives, along with some
SBREFA Panel members, have suggested that the Agency consider allowing
employers to follow the CDC Guidelines as an additional option to
comply with the OSHA standard.
Both the OMB and SBA Panel representatives believe that for at
least some of the work sites OSHA has proposed to cover, the CDC
Guidelines currently provide an adequate measure of protection. They
believe it would be burdensome for employers who are already in
compliance with the Guidelines to have to become familiar with the OSHA
proposal and to implement its provisions. These employers have already
invested in a TB prevention and response program consistent with the
Guidelines. In other words, the employers have conducted their risk
assessments, implemented the suggested provisions and trained their
workers to comply. Moreover, these reviewers point out that where the
Guidelines have allowed for discretion on the part of the employer as,
for example, where an employer may first consider the symptoms
specified in the several CDC Guidelines' definition of ``suspected
infectious TB'' before adopting a definition for his or her own work
site, prevention of the transmission will more easily be achieved
because the employer is allowed to tailor the requirements to actual
conditions in his or her workplace. To assure that the employer's
adoption of the CDC Guidelines is effective, these reviewers
recommended that the employer assert or certify that he or she is in
compliance and, if challenged in an OSHA inspection, prove the efficacy
of his or her program through a performance measure, such as skin test
conversion rates. These reviewers believe that this approach will
result in a more efficient use of scarce health resources.
OSHA agrees that the various CDC Guidelines are the most important
sources for setting an occupational health standard that will reduce or
prevent the spread of TB. However, although certain facilities adhere
to the
[[Page 54227]]
Guidelines, OSHA's research has shown that most facilities have not
fully implemented the CDC recommendations. TB remains an occupational
hazard, and OSHA has preliminarily concluded that the risk of
transmission of TB to employees is significant. OSHA believes there are
a number of reasons why the Guidelines cannot take the place of an OSHA
standard. First, the Guidelines are not written in language that can be
enforced. For example, the Guidelines suggest, recommend and set forth
what an employer could or should do, not what he or she must do. Unless
the Guidelines are converted to regulations, an employer may adhere to
some applicable recommendations while not implementing others, which
could result in uneven and inadequate employee protection. OSHA
standards are written in mandatory language, letting employers and
employees know what they have to do in order to be in compliance with
the regulation. This permits an employer, an employee or a compliance
officer to determine easily whether an entity is in compliance with a
standard. Second, the establishment-specific risk assessment approach
of the Guidelines imposes a tremendous paperwork burden on covered
entities and requires a level of professional expertise in risk
assessment that few entities outside of large hospitals possess. OSHA
believes that recommendations or regulations that necessitate this
level of expertise could make it difficult to determine if an entity is
in compliance. Third, OSHA knows of no objective criterion that could
be reliably used as a measure of proof of an effective program.
Tuberculin skin testing has been suggested as a means of proving
compliance with the CDC Guidelines, e.g., zero conversions would be
accepted as proof that an entity was complying with the Guidelines.
However, the use of conversions as a compliance measurement has two
problems. First, skin test conversions are not necessarily indicative
of implementation of the Guidelines' recommendations. For example, an
entity may have implemented very few of the Guidelines'
recommendations, yet been fortunate enough to experience no
conversions. Therefore, compliance with the Guidelines' recommendations
has not been achieved even though there have been no employee
conversions. Furthermore, while an increase in the number of
conversions indicates employee exposure, a lack of conversions does not
necessarily mean that employees are not being exposed. For example,
some employees have already skin-tested positive, not all exposures
result in conversions, and many entities will not have enough TST-
negative employees to generate sufficient statistical power to
accurately determine an increased conversion rate. With regard to this
last point, the CDC states:
A low number of HCWs in a specific area may result in a greatly
increased rate of conversion for that area, although the actual risk
may not be significantly greater than that for other areas. Testing
for statistical significance (e.g., Fisher's exact test or chi
square test) may assist interpretation; however, lack of statistical
significance may not rule out a problem (i.e., if the number of HCWs
tested is low, there may not be adequate statistical power to detect
a significant difference). Thus, interpretation of individual
situations is necessary. (Ex. 4B)
Second, OSHA believes that reliance on number of TST conversions as a
performance measure is reactive rather than proactive, because it
emphasizes the identification of employees who have already incurred a
status change as a result of an exposure instead of averting exposures.
OSHA believes that compliance with the proposed standard by all
affected facilities within the covered sectors is the way to assure
that employees will be protected from occupational transmission of TB.
The Agency believes that compliance will not be difficult for employers
who have already implemented the Guidelines, because many of the
elements of the Guidelines have been incorporated into the proposed
standard. Also, employers who are not in compliance with the Guidelines
will find that the standard gives them clear instructions on what to
do. In addition, the structure of OSHA's proposed TB standard is
similar to that of the Bloodborne Pathogens standard (BBP). Since the
vast majority of workplaces that will be covered by the TB standard are
subject to BBP, becoming familiar with and implementing the
requirements of the TB standard should not be difficult.
Another issue raised in the review process was what would happen
if, after the OSHA standard was promulgated, the CDC issued a new
guideline that was different from the OSHA standard on an item
addressed by the standard. OSHA believes this is already addressed by
OSHA's citation policy, in particular, the policy for De Minimis
Violations, which states that violations of standards which have no
direct or immediate relationship to safety or health are not to be
included in citations. An example of a de minimis violation occurs when
an employer complies with a proposed OSHA standard or a consensus
standard rather than with the OSHA standard in effect at the time of
the inspection and the employer's action clearly provides equal or
greater employee protection [OSHA Field Inspection Reference Manual,
Instruction CPL 2.103, September 26, 1994]. In cases where an employer
is complying with another provision, such as a consensus standard, the
Agency looks at the consensus standard to make sure the consensus
standard is at least as protective as the OSHA standard. Because CDC
Guidelines reflect the views of many of the country's leading experts
and practitioners in public health measures to prevent the spread of
TB, the updated CDC Guidelines can be assumed to provide equal or
greater protection against occupational transmission of TB to
employees. Because these guidelines carry great authority, the De
Minimis Violation policy would not only be a defense, but would be
accorded such deference that OSHA would incur a heavy burden in showing
that an updated CDC guideline on an item addressed by the OSHA TB
standard did not provide equal or greater protection against
occupational transmission of TB to employees. In order to ensure that
the new CDC Guidelines would be communicated to the OSHA Regions and
others who would need to know, OSHA will issue a Memorandum for
Regional Administrators that will address how the new Guideline could
be implemented in the work place, include a copy of the new Guideline,
and instruct the Regional Administrator to contact area offices and the
OSHA state designees. In addition, the Memorandum would be posted on
the OSHA Computer Information Service (OCIS) and OSHA CD-ROM, which are
accessible to the public.
OSHA seeks comment on all issues related to the CDC Guidelines,
particularly whether they could be implemented in lieu of an OSHA
standard and, if so, how compliance and efficacy could be determined.
Change the Approach to the Identification of Suspect Cases for Homeless
Shelters or Substance Abuse Treatment centers
The SBREFA Panel found that ``Given the current definition of
suspect cases, it is not clear that homeless shelters can comply fully
with the standard. Accordingly, OSHA should reexamine the definition of
suspect cases and/or reexamine its approach to homeless shelters.'' The
SBREFA Panel also noted that this same finding might be relevant to
substance abuse treatment centers. The Panel arrived at this finding as
a
[[Page 54228]]
result of statements made by small entity representatives from the
homeless shelter sector. Small entity representatives concerned with
homeless shelters had serious problems with OSHA's definition of a
suspect case and questioned the feasibility of screening the homeless
by using questions about symptoms. Mr. Wayne Anderson of the National
Health Care for the Homeless Council argued that OSHA's definition of a
suspect case would result in the identification of most of the homeless
as suspect cases during the winter months. Major Dalberg of the
Salvation Army found OSHA's definition of a suspect case confusing and
ambiguous, and stated that it would cover a substantial portion of the
homeless. All three small entity representatives from this sector
questioned whether the standard's screening procedures were workable in
the homeless shelter context. They asserted that the homeless might
avoid screening questions, be unable to answer them, learn how to lie
in response to such questions, or choose to remain on the street rather
than be transferred to a hospital. The small entity representatives for
this sector felt that this portion of the standard should be abandoned.
Because substance abuse treatment centers serve a similar clientele,
the Panel was concerned that the same problems might apply to substance
abuse treatment centers.
To address this issue, and other issues related to the feasibility
of the proposed standard for homeless shelters, OSHA has decided to
hold special sessions during the public hearings on the proposed
standard and to study these issues further through an onsite survey of
a number of homeless shelters. The study will address the following
issues:
Percentage of homeless persons that would be identified by
OSHA's definition of a suspected infectious TB case. (Breakdown of
which symptoms are particularly common so a better definition might be
designed.)
Turnover among the homeless who use shelters.
Employee turnover in homeless shelters.
Trends in number of homeless persons served in shelters.
Criteria currently used by some homeless shelters to
identify suspected infectious TB cases.
Current practices used in homeless shelters to address the
TB hazard (baseline compliance with the draft proposed standard).
--Methods of isolation.
--How suspected TB cases are handled.
Feasibility of having hospitals provide cards to the
homeless indicating TB skin test status.
Number of TB skin test conversions and active cases among
the homeless and homeless shelter employees.
Types of benefits offered to homeless shelter employees
(e.g., health insurance).
Economic feasibility:
--Costs of running a shelter.
--Revenue sources.
--How costs are accommodated as the number of homeless persons served
increases.
--Opportunities for cost pass-through.
Number, location and types (e.g., family-oriented, walk-
in, all-male) of homeless shelters.
Number or proportion of homeless shelter workers who are
unpaid volunteers.
The study will also address the issue of volunteers. The OSH Act
applies to employees, not bona fide volunteers; however, OSHA
understands that some states may, as a matter of state law, require
facilities to provide volunteers with the protections established by
OSHA standards. Thus, OSHA's study will address the following issues:
Economic impacts, in such states, of covering volunteers
(e.g., how costs would be handled, cost pass-through opportunities).
Protections currently offered to volunteers.
The results of the study will be made available for comment in the
public record.
OSHA does not feel that the same problems apply to substance abuse
treatment centers, even if a high percentage of clients might be
defined as suspect cases. Inpatient substance abuse treatment centers
routinely provide some form of entrance physical: this would be an
appropriate time to screen for suspect cases and provide for their
referral.
Outpatient substance abuse treatment centers do not provide any
form of shelter for patients, and thus could readily refer suspect
cases to a hospital without either denying them shelter or having to
pay for the referral. Such a facility could simply insist that suspect
cases not return without data showing that they had been to a doctor
and did not have TB. Since outpatient facilities handle a known
population, such an approach might involve high initial referrals, but
could thereafter settle into a system that checked for suspect cases on
entry to the program.
OSHA estimates that the proposed standard will result in a
reduction of 28 to 33 active disease cases and 2 to 3 deaths per year
in the homeless shelter sector. A standard requiring skin testing and
follow-up treatment alone would have only one third the benefits (such
an approach would reduce the number of active disease cases to only 10
per year and the number of lives saved to 1 per year). The annual costs
of the proposed standard for homeless shelters are estimated to be
$11,287,278, or approximately $1,080 per shelter per year.
OSHA solicits comments on all of the issues listed above to be
covered by its study of homeless shelters, and solicits comment on the
feasibility of the standard for substance abuse treatment centers, and
particularly on the extent to which substance abuse treatment centers
already provide for medical examinations prior to entry into their
programs.
Other Alternatives Considered by OSHA
OSHA considered several additional alternatives but has
preliminarily concluded that the proposed rule will better carry out
the objectives of the OSH Act, while minimizing the economic impact on
affected establishments, and especially on small establishments. OSHA
requests comment on the validity of this preliminary conclusion. First,
OSHA considered making all of the proposed requirements applicable to
every establishment in the covered industries. The prevalence of TB,
however, varies by geographical areas and by the populations served by
facilities in different industries. OSHA therefore believes it will be
possible to reduce significant risk without imposing the full
regulatory requirements on each covered employer. Second, OSHA
considered proposing requirements similar to the CDC's guidelines,
which recommend that risk assessments be conducted to determine the
level of risk in each facility and that the controls implemented vary
in accordance with the level of risk in each facility. This would
require that employers conduct risk assessments by evaluating factors,
such as the number of suspected or confirmed TB cases among patients
and employees, employee tuberculin skin testing results, and the amount
of TB in the community. The CDC recommendations include five levels of
risk (i.e., minimal, very-low, low, intermediate, and high), and the
recommended controls vary by the level of risk. However, adopting such
a requirement in the OSHA standard would impose a large cost and a
heavy paperwork burden on affected facilities.
To avoid imposing unnecessary burdens on facilities where the risk
of
[[Page 54229]]
occupational exposure to M. tuberculosis may be lower, OSHA is
proposing to exempt facilities from certain requirements (i.e.,
respiratory protection, annual medical histories, and annual skin
tests) if the facility transfers, instead of admits, individuals with
suspected or confirmed infectious TB and can additionally demonstrate
that there have been (1) no reported confirmed infectious TB cases in
the county within one of the last two 12-month reporting periods; (2)
fewer than 6 infectious cases of TB in the other 12-month reporting
period; and (3) no infectious cases of TB encountered within their
employees' work settings within the past 12 months.
OSHA also considered proposing a requirement that facilities
implement engineering controls in all intake areas in which early
identification procedures are performed, if the facility had
encountered six or more individuals with confirmed infectious TB in the
past 12 months. The engineering controls considered were single-pass
ventilation, filtration of air through the use of HEPA filters
installed as part of the ventilation system, or stand-alone auxiliary
HEPA filtration units. However, areas where early identification
procedures are performed vary widely in size and configuration, making
it difficult to assess the effectiveness of such controls in reducing
the risk of occupational exposure to M. tuberculosis in a particular
setting. Given the high cost of such controls and the lack of data on
their effectiveness, OSHA is not proposing such a requirement. However,
the Agency requests comment on the potential effectiveness of such
controls in intake areas.
Another alternative considered was to propose that each
occupationally exposed employee be provided with a baseline medical
examination, including a physical examination that emphasized the
pulmonary system and an evaluation for the signs and symptoms of active
TB disease and factors affecting immunocompetence. However, requiring a
baseline physical examination for all exposed employees would impose a
heavy cost burden on affected establishments, and OSHA could find no
evidence that providing a baseline physical examination would
accomplish more than a baseline and annual medical history and
tuberculin skin test in identifying or reducing occupationally induced
TB infections. Thus, OSHA is proposing to require physical examinations
only when they are deemed necessary by the physician or other licensed
health care professional, as appropriate.
OSHA also considered providing medical management and follow-up to
each employee who had been exposed to air originating from an area
where an individual with suspected or confirmed infectious TB was
present. However, stakeholders contacted prior to the issuance of this
proposal stated that a requirement for medical management and follow-up
would impose an unnecessary burden on affected establishments for those
cases that were suspected but were subsequently ruled out. In response
to stakeholders' comments, the Agency is proposing that medical
management and follow-up be provided only when an employee is actually
exposed to an individual with confirmed infectious TB or to air
containing aerosolized M. tuberculosis without the benefit of the
applicable exposure control measures (e.g., respiratory protection)
that would be required under the proposed rule.
Another alternative considered was to require tuberculin skin tests
every six months for all employees assigned to wear respirators.
However, to reduce the burden on facilities that do not encounter many
infectious TB cases, OSHA is not requiring 6-month skin testing for
workers assigned to wear respirators and who work in the intake areas
of facilities where fewer than six confirmed infectious TB cases are
encountered each year.
Rejecting these regulatory alternatives has reduced the estimated
costs of the proposed rule by a minimum of $100 million.
The RFA emphasizes the importance of performance-based standards
for small businesses. OSHA considers the proposed standard to be highly
performance oriented. The proposed standard emphasizes the early
identification and isolation of individuals with suspected or confirmed
infectious TB. Affected employers have been allowed wide discretion in
the selection of procedures they use to achieve this. Without early
identification and isolation, prevention of the spread of TB from
patients and clients to workers is virtually impossible. OSHA has also
limited requirements for work settings located in a county that, in the
past 2 years, has had zero cases of confirmed infectious TB reported in
one year and fewer than 6 cases of confirmed infectious TB reported in
the other year. OSHA welcomes comment on other ways that the standard
can be made more performance oriented.
Another approach considered is compliance date phase-ins for small
businesses. OSHA is proposing to extend the standard's compliance
deadlines for engineering controls and has considered extending the
compliance deadlines for the other proposed requirements; however,
since these other requirements are not capital-intensive for most
affected facilities, such an extension would do little to reduce the
burden on small entities and would only result in a delay in the
protection of workers provided by compliance with the proposed rule.
OSHA solicits comment on the effects of extending phase-in dates for
the other proposed requirements, particularly those for respirators,
for small entities.
After considering all of the above alternatives and adopting those
that were consistent with the mandate imposed by the OSH Act, OSHA has
developed a proposed rule that will minimize the burden on affected
employers, while maintaining the necessary level of worker protection.
OSHA's Response to SBREFA Panel Recommendations
Table VII-7 lists the SBREFA Panel Recommendations and OSHA's
response to these recommendations. The complete SBREFA Panel Report is
available for comment in the record as Exhibit 12 of Docket H-371.
Table VII-7.--OSHA's Responses to SBREFA Panel Recommendations
------------------------------------------------------------------------
Panel recommendation OSHA response
------------------------------------------------------------------------
OSHA should define the terms These terms are now defined in
``establishment,'' ``firm'' and Chapter VI of the PEA.
``facility'' in the IRFA.
OSHA should consider analyzing OSHA now uses the SBA
additional size classes of firms. definitions of small entities
and also analyzes entities
with fewer than 20 employees
in the IRFA.
OSHA should clarify and more carefully OSHA has provided tables
explain the requirements and engage in illustrating requirements for
extensive outreach efforts to assure groups of affected firms,
that the regulated community added many clarifications to
understands the regulation. the Preamble and regulatory
text, and plans extensive
outreach upon publication of
the final standard (see
Preamble Section IX).
[[Page 54230]]
OSHA should reexamine the definition of OSHA will conduct a special
a suspect case and/or reexamine its study of homeless shelters.
approach to homeless shelters. This study is discussed in the
IRFA. OSHA will also designate
certain hearing dates for
persons who wish to testify on
homeless shelter issues.
OSHA should reconsider applying the OSHA has explained in the IRFA
standard to substance abuse centers. why it thinks that its
treatment of substance abuse
treatment centers is feasible
and has solicited comment on
this issue in the Issues
Section of the Preamble.
OSHA should more carefully address the OSHA has added a discussion of
economic impacts on facilities that this issue to Chapter VI of
rely on Medicaid/Medicare or the PEA.
charitable funding.
OSHA's preamble and IRFA should explain OSHA has added a preamble
OSHA's role and authority as compared discussion of why OSHA
to other voluntary and regulatory regulates occupational
organizations; preamble should explain exposure to TB, why other
ongoing cooperative efforts; solicit organizations are unable to do
comments on conflicts and ways of so effectively, and how OSHA
better coordinating with other has worked with other
organizations. organizations. OSHA solicits
comments on possible conflicts
and better methods of
coordination.
OSHA should examine additional OSHA has added a discussion of
alternatives, such as revising the additional alternatives
proposed standard for greater suggested by SBREFA Panel
consistency with CDC guidelines. members to the IRFA and has
solicited comment on these
alternatives in the Preamble.
OSHA should clarify that employers OSHA has clarified this issue
would only be required by the standard in the Preamble.
to determine the TB status of their
county once per year, rather than
monthly.
OSHA should reexamine the standard and OSHA has modified the standard
the economic analysis to ensure that to allow portability of non-
the issues of part-time, multi- site specific elements of
employer, and off-site workers have training and to allow
been adequately addressed. OSHA should portability of skin tests. For
also specifically address the issue of off-site workers, OSHA has
portability of training. OSHA should clarified in the Preamble that
clarify the term ``accessibility'' in the standard may be made
the context of employers with off-site available at the primary
employees. workplace facility, provided
there is a mechanism for
immediate availability of
information during the
workshift.
OSHA should clarify exactly what is The Summary and Explanation
required for temporary AFB isolation. Section of the Preamble
describes temporary AFB
isolation, and OSHA's
assumptions concerning the
costs of such units are given
in Chapter V of the PEA.
OSHA should clarify that engineering OSHA has clarified the point in
control provisions do not apply to Section IX of the Preamble.
home health care.
OSHA should explain the differences in OSHA has explained this
protection provided by surgical masks difference in Section IX of
and respirators. the Preamble.
OSHA should explain the reasons for its OSHA has discussed this issue
detailed respiratory protection in the Summary and Explanation
program, why it considers Section of the Preamble.
manufacturers' instruction inadequate
as a substitute for a respirator
program, and why annual respirator
program evaluation is necessary.
OSHA should explain its intent to fold OSHA has discussed this issue
many aspects of respiratory protection in the Summary and Explanation
provisions for occupational exposure Section of the Preamble.
to TB into the upcoming respirator
standard.
OSHA should explain the number of OSHA provides an estimate of
employees required to have medical the number of employees
surveillance in homeless shelters, the requiring medical surveillance
elements of a written medical opinion, in Chapter V of the PEA. The
and the importance of two-step skin regulation lists the elements
testing. of a medical opinion. The
Preamble explains the
importance of two-step skin
testing.
OSHA should explain its basis for OSHA has discussed this issue
believing that two-step skin testing in the Summary and Explanation
is appropriate for employees who have Section of the Preamble.
had BCG vaccinations.
OSHA should clarify the interaction of OSHA has addressed this
workers' compensation and medical interaction in both the
removal protection and examine more Preamble and the IRFA, and has
carefully the costs and impacts of provided a special discussion
medical removal protection on small in Chapter VI of the PEA on
firms that actually have an employee the economic impacts of the
with a serious and costly active case medical removal protection
of TB. provision on small firms. OSHA
has solicited comment on this
issue.
OSHA should examine the potential cost OSHA has modified the proposed
savings associated with a provision regulation to allow
that allows training to be portability of non-site
``portable'' (assuming the training is specific training and to allow
equivalent to that required by the employers to demonstrate
standard). OSHA should clarify that employee competence rather
posting a copy of the standard will be than provide annual
considered an adequate means of retraining. OSHA has clarified
providing employees with the standard. in the Preamble that posting a
OSHA should clarify its performance- copy of the standard will be
oriented interpretations of the considered an adequate means
training requirements in the Preamble, of providing employees with
and OSHA should examine the need for the standard. OSHA has
annual retraining for all employees. clarified in the preamble that
the training is performance
oriented and need not include
training in topics not
relevant to an employee's
duties.
OSHA should clarify how the OSHA has added a discussion of
identification, referral, and this issue to the IRFA and the
notification requirements of the Preamble.
proposed standard can be met without
breaching federal and state
confidentiality regulations and
statutes.
OSHA should include a discussion of the OSHA has added a discussion of
interaction between medical removal this issue to the IRFA and the
protection provisions and the preamble.
Americans with Disabilities Act and
the Family and Medical Leave Act.
OSHA should solicit comment and request OSHA has solicited comment on
data on industry turnover rates in the this issue.
Summary of the Preliminary Economic
Analysis in the Preamble.
OSHA should reexamine its estimate of OSHA has reexamined the issue
the number of hospices and adopt the of the number of hospices and
most accurate figure. retained its original
estimate. OSHA has clarified
that this estimate includes
only free-standing hospices.
Hospices that are parts of
nursing homes and hospitals
are included in estimates for
those sectors.
[[Page 54231]]
OSHA should clarify why family practice OSHA has added physicians who
physicians were not included in the conduct high hazard procedures
analysis, and solicit comment on the to its economic analysis and
extent to which family practitioners has sought comment on whether
conduct the kind of hazardous family practitioners commonly
procedures that would place them conduct such procedures.
within the scope of the rule.
OSHA should consider estimating the OSHA has explained in the
effects of the rule on volunteers and Preamble that the standard
should include a discussion explaining does not apply to bona fide
that the proposed rule does not apply volunteers. OSHA has solicited
to volunteers, although some states comments on states or
may choose to apply it to these localities that elect to
categories of individuals. extend OSHA requirements to
volunteers and on the number
of affected volunteers. OSHA
will further examine the issue
of the number of potentially
affected volunteers in
homeless shelters in its
homeless shelter study.
OSHA should solicit comment on the OSHA has solicited comments on
number of small government this issue in the Preamble.
jurisdictions affected by the draft
proposed standard.
OSHA should include a discussion of OSHA has provided an estimate
tribal governments in its analysis and of the number of affected
solicit comment on this issue. tribal facilities and has
sought comment from tribal
governments in the Preamble.
OSHA should remind small entities that OSHA has solicited comments on
OSHA's risk assessment will be part of several specific aspects of
the public record and is subject to the risk assessment and
comment, and that small entities may benefits analysis, and on
submit any appropriate additional these analyses as a whole.
literature or studies that OSHA should
consider in determining the risk of
occupational TB.
OSHA should discuss the annualization Chapter V of the PEA and the
of costs in greater detail in the summary of the PEA in the
economic analysis. Preamble now discuss the
annualization of costs.
OSHA should clarify its position on the OSHA has reanalyzed the costs
costs and durability of various of respirators in hospitals,
respirators that can be used to comply and has added a discussion of
with the standard, and should seek the uncertainties concerning
additional comment on the costs and the costs and durability of
durability of respirators. respirators to the PEA. OSHA
has solicited comments on
these issues in the Preamble.
OSHA should perform further analyses to OSHA specifically addresses
identify the marginal costs of medical this issue in Chapter VI of
removal protection above and beyond the PEA and has sought comment
worker compensation, should further on this issue.
assess the probability that employers
will actually incur costs for medical
removal protection if they have an
employee with an active case of TB,
and should incorporate the results of
this reexamination into its
determination of feasibility.
OSHA should reassess whether affected OSHA has further examined this
facilities have reasonable access to issue, and found that affected
facilities with AFB isolation rooms, facilities do have reasonable
solicit comments on this issue, and access to AFB isolation rooms;
incorporate the results of this however, OSHA is seeking
reexamination into its determination comments on whether some
of feasibility. affected facilities may not
have adequate local access to
facilities with AFB isolation.
OSHA should reexamine its analysis of OSHA has discussed this issue
the economic impacts of the proposed in Chapter VI of the PEA.
rule on firms, such as emergency
medical services firms, that operate
under the constraint of being unable
to charge some of their clients.
------------------------------------------------------------------------
VIII. Unfunded Mandates Analysis
The proposed TB standard has been reviewed in accordance with the
Unfunded Mandates Reform Act of 1995 (UMRA) (2 U.S.C. 1501 et seq.) and
Executive Order 12875. OSHA estimates that compliance with the proposed
standard will require expenditures of more than $100 million each year
by employers in the private sector. Therefore, the proposed TB standard
establishes a federal private sector mandate and is a significant
regulatory action within the meaning of Section 202 of UMRA (2 U.S.C.
1532). OSHA has included this statement to address the anticipated
effects of the proposed TB standard pursuant to Section 202.
OSHA standards do not apply to state and local governments except
in states that have voluntarily elected to adopt an OSHA State Plan.
Consequently, the proposed TB standard does not meet the definition of
a ``federal intergovernmental mandate'' (Section 421(5) of UMRA (2 USC
658 (5)). In sum, the proposed TB standard does not impose unfunded
mandates on state, local, and tribal governments.
The remainder of this section summarizes OSHA's findings as
required by Section 202 of UMRA (2 U.S.C. 1532):
This standard is proposed under Section 6(b) of the OSH Act. The
proposed standard has annualized costs estimated at $245 million and
would save an estimated 138 to 190 lives per year as a result of TB
infections avoided. An estimated 1,772 to 2,442 active TB cases will be
averted annually as a result of the proposed rule. Compliance will also
result in an estimated 24,333 to 32,719 infections averted. The
proposed standard will impose no more than minimal costs on state,
local or tribal governments. OSHA pays 50 percent of State plan costs
but does not provide funding for state, local or tribal governments to
comply with its rules.
OSHA does not anticipate any disproportionate budgetary effects
upon any particular region of the nation or particular state, local, or
tribal governments, or urban or rural or other types of communities.
Chapters V and VI of the economic analysis provide detailed analyses of
the costs and impacts of the proposed standard on particular segments
of the private sector. OSHA has analyzed the economic impacts of the
standard on the affected industries and found that compliance costs
are, on average, only 0.18 percent of sales, and that few, if any,
facility closures or job losses are anticipated in the affected
industries. As a result, impacts on the national economy would be too
small to be measurable by economic models. OSHA requests information on
state and local government issues.
Pursuant to Section 205 of the UMRA (2 U.S.C. 1535), and having
considered a variety of alternatives outlined in the Preamble and in
the Regulatory Flexibility Analysis above, the Agency preliminarily
concludes that the
[[Page 54232]]
proposed rule is the most cost-effective alternative for implementation
of OSHA's statutory objective of reducing significant risk among
employees to the extent feasible. OSHA solicits comment on these
issues.
IX. Environmental Impacts
The provisions of this proposed standard have been reviewed in
accordance with the requirements of the National Environmental Policy
Act (NEPA) of 1969 [42 U.S.C. 432, et seq.], the Council on
Environmental Quality (CEQ) NEPA regulations [40 CFR Part 1500], and
OSHA's DOL NEPA Procedures [29 CFR Part 11]. As a result of this
review, OSHA has preliminarily determined that this proposed standard
will have no significant effect on air, water, or soil quality, plant
or animal life, use of land, or other aspects of the environment.
X. Summary and Explanation of the Standard
Based on currently available data in the record, OSHA has
preliminarily concluded that the requirements set forth in this
proposed standard are those that are necessary and appropriate to
provide adequate protection to employees exposed to tuberculosis (TB).
In the development of this proposed standard, OSHA has carefully
considered the numerous reference works, journal articles, and other
data collected by OSHA since the initiation of this proceeding. In
particular, OSHA has carefully considered the recommendations given in
the document, ``Guidelines for Preventing the Transmission of
Mycobacterium tuberculosis in Health-Care Facilities'' published by the
Centers for Disease Control and Prevention beginning on page 54242 in
the Federal Register of October 28, 1994 (Ex. 4B). OSHA also held a
series of informal stakeholder meetings during the development of the
proposal and considered the major points raised by the stakeholders
during these meetings (Ex. 10). In addition, the proposal has undergone
the Panel review process required by the Small Business Regulatory
Enforcement Fairness Act (SBREFA)(5 U.S.C. Chapter 8) (Exs. 11 and 12).
All of the information developed to assist the small entity
representatives involved in the SBREFA panel process, the comments of
these representatives, and the Panel's findings and recommendations to
OSHA have been placed in the rulemaking record (Exs. 11 and 12).
Upon publication of the final standard, the Agency will undertake a
number of compliance assistance activities that will be particularly
beneficial to small entities. Past compliance assistance activities
have included: publication of booklets summarizing the provisions of
the standard; development of a compliance directive that answers
compliance-related questions about the standard; development of
compliance guides directed at assisting small businesses in complying
with the standard; designation of certain OSHA employees in each
Regional office with the responsibility of answering questions from the
public about the standard; development of training materials; and
provision of speakers and information for meetings and workshops of
affected parties (particularly small business entities). OSHA
anticipates initiating similar activities upon publication of the final
standard for occupational exposure to tuberculosis.
Paragraph (a) Scope
Tuberculosis is a well-recognized occupational hazard (Ex. 4B). As
discussed in the Health Effects section above, there are numerous
epidemiological studies, case reports, and outbreak investigations that
provide evidence to show that employees who are exposed to aerosolized
M. tuberculosis have become infected with TB and in some cases have
developed active TB disease. Of particular concern is the emergence of
strains of multidrug-resistant TB. MDR-TB presents an additional hazard
because individuals with MDR-TB may be infectious for weeks or months
until an effective drug regimen can be successfully implemented and the
patient rendered noninfectious. This in turn increases the likelihood
that employees who must provide health care or other services to these
individuals will be exposed. The risk of death from infections with
MDR-TB is markedly increased. Outbreaks involving strains of MDR-TB
have had mortality rates as high as 75% with death occurring 4 to 16
weeks after the diagnosis of disease (Ex. 3-38A).
Most of the TB outbreaks investigated occurred in large
metropolitan areas. However, a recent study has shown that MDR-TB
spread from New York City to patients in Florida and Nevada and health
care workers in Atlanta, Georgia and Miami, Florida and to staff and
patients in a nursing home in Denver, Colorado (Ex. 7-259). In
addition, a growing percentage of TB cases are occurring among the
foreign born. CDC reported that in 1995 the number and proportion of
cases among the foreign-born had increased 63% since 1986 (Ex. 6-34).
These two pieces of information taken together clearly illustrate the
relationship between population mobility and the spread of TB disease.
Thus, TB is a nationwide problem. Although the total number of cases
declined to its pre-1985 levels after a resurgence from 1985 to 1994,
the rate of active TB cases reported in 1995 (i.e., 8.7/100,000) is
still two and one half times greater than the target rate of 3.5 active
cases per 100,000 population for the year 2000 proposed by the Advisory
Committee on the Elimination of Tuberculosis (Ex. 6-19). In addition,
there is substantial variability from year to year in the increases and
decreases in the number of cases reported by each state. In 1995, all
fifty states reported cases of TB, and fifteen of these reported
increases over 1994 (Ex. 6-34). At the county level, approximately 57%
of counties in the U.S. reported one or more cases of active TB, with
17% of the counties in the U.S. reporting 5 or more cases (Ex. 7-262).
In addition, approximately 91% of the U.S. population resides in the
counties that reported one or more cases of active TB. Thus, while 43%
of the counties in the U.S. reported no cases of active TB, 10% of the
U.S. population resides in those counties. The nationwide prevalence of
TB infection in the U.S. population in 1994 (age 18 years an older) is
approximately 6.5 percent.
The recent resurgences in the number of reported cases of active TB
have brought to attention a number of problems in existing TB control
plans. The problem is most apparent in health care facilities such as
hospitals, but it also extends to other work settings where the
population served is at increased risk for tuberculosis, such as
shelters for the homeless, correctional institutions and settings where
high-hazard procedures are performed.
There are a number of factors that make occupational exposure to
tuberculosis an important concern at the present time. One factor is
that the results from OSHA's quantitative risk assessment show a high
potential for TB infection for employees who work in close proximity to
individuals with infectious TB. A second factor is that the cases of
tuberculosis are not distributed evenly throughout the entire
population. There is a relatively high prevalence of tuberculosis
infection and disease in certain populations, such as residents of
nursing homes and inmates of correctional institutions. A third factor
is the rise of MDR-TB. These factors increase the risk for workers who
have occupational exposure. Occupational exposure occurs through
contact with air that may contain aerosolized M. tuberculosis as a
result of the performance of an employee's
[[Page 54233]]
duties. Most often this occurs when an employee is working in the same
environment with an individual with infectious TB. It could also occur
when repairing air systems that may be carrying aerosolized M.
tuberculosis.
Individuals with infectious tuberculosis expel airborne particles
called droplet nuclei when they cough, sneeze, or speak. These droplet
nuclei contain the organism that causes tuberculosis, M. tuberculosis.
Normal air currents can keep these droplet nuclei airborne for long
periods of time and spread them throughout a building (Ex. 5-5). When
employees breathe the air that contains M. tuberculosis, they are at
risk for TB infection which may result in illness and, in some cases,
death. Employees also may be exposed when laboratory procedures produce
aerosols of M. tuberculosis. There is an extensive discussion of the
scientific literature related to occupational transmission in Section
IV, Health Effects, which will not be repeated here.
Because the CDC does not consider fomites, e.g., objects such as
clothing or silverware, to present a hazard for transmission of M.
tuberculosis, this standard is designed to eliminate or reduce airborne
exposures only. Even though it is well established that exposure to TB
contaminated air is the route of exposure related to the development of
disease, it is not known what levels of contamination in the air cause
the disease. Unlike toxic chemicals, a Permissible Exposure Limit (PEL)
for air concentration of TB cannot be determined. As described in the
Health Effects section of this preamble, it is known that a number of
factors contribute to the probability of infection. For example,
exposures of relatively short duration, such as a day or two, can
result in infection of the employee. OSHA has used these findings to
show that certain types of work, in certain industries, can result in
significant risk of TB infection. For these reasons, OSHA is defining
the scope of the standard by listing the locations and services where
this proposed standard would apply. Employers with employees working at
those locations, and employers whose employees provide the listed
services, are covered by the standard. The proposed standard applies to
occupational exposures to tuberculosis that occur in certain specified
workplaces, such as a hospital, or as the result of providing services,
such as emergency medical treatment. Paragraphs (a)(1) through (10) of
the proposal describe the various work settings and services that are
covered under the scope of the standard.
Paragraph (a)(1) states that the standard applies to occupational
exposure to TB occurring in hospitals. The record contains many
examples of occupational exposures with resultant TB infection and
disease that have occurred in hospitals (e.g., Exs. 5-11; 5-15; 7-43;
7-45). Recent outbreaks involving multidrug-resistant strains of M.
tuberculosis have compounded the long recognized risk of TB in such
settings.
Hospitals not only provide medical care for persons with diagnosed
tuberculosis, they also provide medical care for individuals who may be
at increased risk for TB. For example, hospitals provide isolation for
individuals with suspected or confirmed infectious TB and contain rooms
or areas where high-hazard procedures on individuals with infectious TB
are performed that place employees at risk of exposure. In addition,
the client population encountered in hospitals is generally at higher
risk of developing active TB. Individuals with HIV disease, for
example, are at increased risk for developing disease when they have
been infected with M. tuberculosis. In addition, medically underserved
populations with an increased prevalence of tuberculosis (e.g.,
homeless persons) may seek acute care in the emergency rooms of
hospitals.
Employees who are at risk for occupational exposure and potential
infection and disease include all employees who have direct contact
with persons with infectious tuberculosis. These may include but are
not limited to physicians, nurses, aides, dental workers, medical
technicians, workers in laboratories and autopsy suites, and emergency
medical service personnel (Ex. 4B). They may also include persons not
involved in direct patient care but who have occupational exposure as a
result of providing other services such as dietary, housekeeping, and
maintenance staff.
Paragraph (a)(2) covers occupational exposure occurring in long-
term care facilities for the elderly. Persons aged 65 and older
constitute a large repository of M. tuberculosis infection in the
United States (Ex. 6-14). Many of these individuals were infected many
decades ago when TB was a much more common disease. Some of the TB
occurring in this age group arises from preexisting infection of long
duration and other cases may be the result of recent infections. In
addition, elderly persons residing in nursing homes are at greater risk
than elderly persons living in the community. In its 1990 guidelines,
``Prevention and Control of Tuberculosis in Facilities Providing Long-
term Care to the Elderly,'' the CDC cited 1984-1985 data indicating a
TB case rate of 39.2 per 100,000 population, a rate that was twice that
of elderly persons living in the community (Ex. 6-14). The same
document stated that CDC had found that the increased risk for nursing
home employees was three times higher than the rate expected for
employed adults of similar age, race, and sex. Examples of employees in
long-term care facilities who may have occupational exposure include,
but are not limited to, registered nurses, licensed practical nurses,
nursing assistants, and auxiliary personnel. OSHA has not included
other long-term care facilities under the scope of the standard. The
Agency requests comment and supporting data on whether it is
appropriate to expand the scope of the standard to include other long-
term care facilities that may provide health care or other services to
individuals who may be at an increased risk of developing infectious
TB, thereby presenting a potential source of exposure to employees
working in those facilities. An example of another long-term care
facility is a psychiatric hospital.
Paragraph (a)(3) covers occupational exposure occurring in
correctional facilities and other facilities that house inmates or
detainees. Facilities such as prisons, jails and detainment centers
operated by the Immigration and Naturalization Service (INS) would be
included in the scope of the standard. The CDC considers TB to be a
``major'' problem in correctional institutions, with cases occurring at
a frequency three times that of the general population (Ex. 7-25). In
addition to a number of outbreaks that have occurred, the overall
incidence of tuberculosis in the prison population is increasing. This
can be attributed to, (1) the over-representation of populations at
high risk for TB in prisons and jails, and (2) environmental factors
that promote the transmission of TB. Compared to the general
population, inmates have a higher prevalence of TB infection. The
population of correctional facilities is also characterized as having a
high prevalence of individuals with HIV infection and intravenous drug
users, factors that place these inmates at a higher risk of developing
active TB. In addition, many prisons and jails are old, overcrowded,
and have inadequate ventilation. Inmates may be moved frequently within
a facility and between facilities, increasing the number of persons,
both inmates and employees, exposed to an infected individual and
making contact tracing difficult.
[[Page 54234]]
Medical records and treatment information may not follow the inmate in
a timely manner, which may, in turn, lead to inadequate drug therapy.
Detention facilities, such as those operated by the INS, may house
persons who are entering this country from countries with a prevalence
of TB many times that of the U.S. population (Ex. 6-26). In addition,
there may be a substantial number of individuals in these facilities
currently awaiting deportation who have an additional increased risk of
TB because they have been previously incarcerated in correctional
institutions. In 1995, CDC reported that approximately 36% of the total
reported cases of active TB were among the foreign-born (Ex. 6-34).
This marks a 63% increase since 1986. In addition, among those persons
whose records contained information on date of arrival to the U.S.,
approximately 30% developed active TB within one year of entering the
country and approximately 53% developed active TB within 5 years of
entering the country. Employees who may have occupational exposure in
these facilities include, but are not limited to, correctional
officers, physicians, dentists, nurses, and other health care workers.
Paragraph (a)(4) covers occupational exposure occurring in
hospices. CDC identified hospices as one of the inpatient health care
facilities to which its 1994 TB guidelines apply. CDC's Guidelines
recommend that individuals with suspected or confirmed infectious TB be
managed in the same manner using similar methods of infection control
as recommended for hospitals. Hospices serve the same high-risk
populations that hospitals serve. In addition, individuals receiving
hospice care may be at increased risk for tuberculosis if they are
members of a high risk group, which includes groups whose members have
a medical condition that increases the likelihood of developing active
tuberculosis (e.g., HIV disease, end stage renal disease, certain
carcinomas). Employees who may have occupational exposure include, but
are not limited to, physicians, nurses, aides, social workers, and
other health care workers.
Occupational exposure occurring in shelters for the homeless is
covered under paragraph (a)(5). Residents of shelters for the homeless
comprise a population that is also at increased risk for tuberculosis.
Members of this population are more likely to have risk factors that
are associated with TB than the general population although the exact
prevalence of TB in this population is unknown. The data quoted in
CDC's 1992 document ``Prevention and Control of Tuberculosis Among
Homeless Persons'' indicated a prevalence of clinically active
tuberculosis among homeless adults ranging from 1.6% to 6.8% (Ex. 6-
15). The prevalence of latent tuberculosis ranged from 18% to 51% and
there was a point prevalence of active TB of 968 cases/100,000 homeless
adults (Ex. 6-15). Similar to the population in correctional
facilities, residents of homeless shelters have a high prevalence of
HIV infection and intravenous drug use, factors that increase the
likelihood that their infections will progress to active TB. In
addition, environmental factors such as overcrowding and poor
ventilation promote the transmission of disease. Examples of employees
who may have occupational exposure include, but are not limited to,
intake workers and health care workers who have contact with residents
of homeless shelters.
Paragraph (a)(6) covers occupational exposure occurring in
facilities that provide treatment for drug abuse. Based on tuberculin
skin testing reported in 1993, 13.3% of the clients of drug treatment
facilities had evidence of TB infection (Ex.6-8). Many of these persons
have a history of intravenous-drug use and either have or are at risk
for HIV infection. These persons are at increased risk for developing
active TB and transmitting the disease to others. Many of these
individuals may discontinue treatment prematurely even if they are
diagnosed and started on effective drug treatment. In addition, the CDC
reported that studies in some areas have shown that over 20% of
selected inner city intravenous drug user populations have tuberculous
infection (Ex. 3-37). The CDC thus concluded that drug center clients
and staff are at risk of becoming infected. Employees in drug treatment
facilities who may have occupational exposure include, but are not
limited to, counselors, nurses, physicians and other staff.
Work settings where occupational exposure occurs as a result of the
performance of high-hazard procedures, which, for the purposes of this
standard, are certain procedures performed on individuals with
suspected or confirmed infectious TB, are also covered under the scope
of the standard as stated under paragraph (a)(7). High-hazard
procedures are procedures that are cough-inducing or aerosol-generating
that are likely to result in droplet nuclei being expelled into the
air. A definition and discussion of high-hazard procedures can be found
under paragraph (j), Definitions, of this Summary and Explanation.
Health care workers and other employees who are either performing or
assisting with these procedures or are in the general vicinity are at
an increased risk of inhaling droplet nuclei and therefore have
occupational exposure. The 1994 CDC guidelines recommend in Section G,
``Cough-Inducing and Aerosol-Generating Procedures'' that special
precautions be taken when these procedures are performed (Ex. 4B).
Health care workers, such as physicians, nurses, technicians and others
who perform or assist in the performance of high-hazard procedures have
occupational exposure. Other employees who may be in the room or area
when such procedures are performed would be expected to have
occupational exposure as well.
Paragraph (a)(8) applies to occupational exposure that occurs in
laboratories that handle specimens that may contain M. tuberculosis,
process or maintain those specimens or the resulting cultures, or
perform any related activity that may result in the aerosolization of
M. tuberculosis. M. tuberculosis is a proven hazard to laboratory
personnel (Exs. 7-68, 7-72, 7-142, 7-143). Aerosols present the
greatest hazard in laboratories. Tubercle bacilli may be present in
sputum, gastric lavage fluids, cerebrospinal fluid, urine, and in
lesions from a variety of tissues. In addition, the bacilli are grown
in culture to increase their concentration beyond what would normally
be found in the sample for purposes of identification and
susceptibility testing. The bacilli may survive in heat-fixed smears
and may be aerosolized in the preparation of frozen sections and during
manipulation of liquid cultures. CDC/NIH's manual ``Biosafety in
Microbiological and Biomedical Laboratories'' recommends Biosafety
Level 2 or 3 for such laboratories depending on the procedures being
performed (Ex. 7-72). Employees who may have occupational exposure
include a wide variety of laboratorians. Examples include, but are not
limited to, medical technologists, laboratory technicians, physicians,
and research scientists.
Occupational exposure incurred by temporary or contract employees
is also covered under the Scope to the extent that the occupational
exposure occurs in one of the work settings listed under paragraphs
(a)(1) through (a)(8). For example, if a nurse working for a temporary
employment service were hired by a hospital to work on a TB ward, that
temporary nurse would be covered under the scope of the standard.
Physicians who are employees (e.g., of an independent corporation) yet
who
[[Page 54235]]
practice and are exposed in a covered facility, such as a hospital, are
also covered by the standard. Similarly, in any of the work settings
listed under paragraph (a)(1), temporary or contract personnel who
incur occupational exposure to TB as a result of their temporary or
contract work would be covered by the standard. The occupational
exposure experienced by these employees would be expected to be similar
to that of other employees performing the same tasks and procedures in
the work setting that has contracted for their services. A note has
been added to the proposed standard to make clear that these types of
employees are covered under the scope.
This note also clarifies that repair, replacement, or maintenance
personnel, working in any of the work settings covered under paragraphs
(a)(1) through (a)(8), who service air systems or equipment or who
renovate, repair or maintain areas of buildings that may reasonably be
anticipated to contain aerosolized M. tuberculosis are also covered
under the scope of the standard. The standard requires the use of
engineering controls, such as isolation rooms, to reduce the
concentration of droplet nuclei and therefore reduce the likelihood of
TB infection and subsequent illness. The ventilation systems that
exhaust air from isolation rooms may reasonably be anticipated to
contain aerosolized M. tuberculosis. Maintenance and other workers who
are responsible for the servicing and repair of ventilation systems
that handle air that may contain aerosolized M. tuberculosis are at
risk for occupational exposure when, as the result of performing their
duties, they are exposed to TB contaminated air moving through the
ventilation system. Examples of employees who may have occupational
exposure include heating, ventilation, and air conditioning (HVAC)
maintenance personnel.
In addition, there may be employees who are responsible for
renovating, repairing, or maintaining areas of buildings where exposure
to aerosolized M. tuberculosis may occur other than those associated
with the ventilation systems. Maintenance staff who need to repair
fixtures in an isolation room, or contractor personnel hired to provide
housekeeping in isolation rooms or areas, are examples of such
employees who would also be covered under the standard. OSHA expects
that such exposures would occur only rarely. In many circumstances,
minor non-emergency maintenance activities could be performed by health
care personnel required to enter the isolation rooms or areas for other
reasons, such as to care for a patient. However, there may be
activities that necessitate the expertise of certain maintenance
employees which could place those employees at risk of occupational
exposure. Those employees would therefore be covered under the scope of
the standard.
Paragraph (a)(9) applies to occupational exposure occurring during
the provision of social work, social welfare services, teaching, law
enforcement or legal services, where the services are provided in the
facilities included in paragraphs (a)(1) through (a)(8), or in
residences, to individuals who are in AFB isolation, or are segregated
or otherwise confined due to having suspected or confirmed infectious
tuberculosis. This paragraph is intended to cover those types of
employees who must provide services to individuals who have been
identified beforehand as having suspected or confirmed infectious
tuberculosis and who have either been isolated or segregated in
isolation rooms or areas or have been confined in their homes. For
example, certain social workers may need to enter AFB isolation rooms
or areas or visit homes of people who have suspected or confirmed
infectious tuberculosis for the purposes of collecting information or
providing discharge planning. While OSHA believes that it would be
preferable to collect such information over the telephone in order to
prevent occupational exposure, the Agency realizes that there may be
situations where direct contact with these isolated or confined
individuals may be necessary. In these limited situations, these
employees would be covered under the scope of the standard. There may
also be situations where teachers may be providing tutoring to
individuals isolated with suspected or confirmed infectious
tuberculosis. Again, OSHA believes that such situations would be
limited and that most educational instruction could be delayed until an
individual was determined to be noninfectious. However, where teachers
must provide instruction to individuals identified as having suspected
or confirmed infectious TB, those teachers would be covered under the
scope of the standard. In addition, certain law enforcement officers
might have to be in contact with individuals who have been identified
as having suspected or confirmed infectious tuberculosis. For example,
they may have to transfer such an individual from a correctional or
detainment facility to a hospital for diagnosis or treatment. Because
these workers must be in direct contact with the individual during
transport, perhaps for long periods of time and probably in an enclosed
vehicle, such employees could incur significant occupational exposure.
Paragraph (a)(9) would assure that such employees would be covered
under the standard. Similarly, there may be occasions where attorneys
must consult with clients or inmates who have been isolated or
segregated because they have been identified as having suspected or
confirmed infectious tuberculosis. Such attorneys would be covered
under the standard in the limited situations where these consultations
cannot be done by phone or delayed until the individual has been
determined to be noninfectious. Under paragraph (a)(9), OSHA has
specified certain employee groups that it believes would have to enter
AFB isolation rooms or areas or homes where individuals are confined
due to suspected or confirmed infectious TB, in order to provide
services which may result in occupational exposure. OSHA requests
comments and data as to whether there are other employee groups that
may incur occupational exposure and thus need protection under this
paragraph.
Paragraph (a)(10) applies to occupational exposure occurring during
the provision of emergency medical services, home health care, and
home-based hospice care. Emergency medical service employees may
provide emergency treatment and transportation for individuals with
suspected or confirmed tuberculosis. For example, in addition to
serving the same high-risk client population as hospitals, emergency
medical services are often used to transport individuals who have been
identified as having either suspected or confirmed infectious
tuberculosis from a facility with inadequate isolation capabilities to
another facility better equipped to isolate these individuals.
Proximity to the patient and time spent within an ambulance or other
emergency vehicle affects the likelihood of occupational exposure as
the result of breathing droplet nuclei generated when the patient
coughs or speaks. Examples of employees who may have occupational
exposure include but are not limited to emergency medical technicians,
paramedics, and, in some localities, fire fighters.
The 1994 CDC guidelines identify health care workers who provide
medical services in the homes of patients with suspected or confirmed
infectious tuberculosis as being at risk and recommend precautions to
be used in these settings (Ex. 4B). Employees who provide home-based
care serve a
[[Page 54236]]
client population similar to that of hospitals (e.g., individuals who
may be immunocompromised). Employees such as nurses and aides who
provide care to these individuals would be expected to have
occupational exposure.
OSHA is also proposing that certain limited construction activities
be included under the scope of the standard; however, the Agency
believes that the proposed standard would have little impact on this
sector. The standard would apply to construction operations occurring
in the work settings covered by the scope of the standard where there
is a reasonable anticipation of exposure to aerosolized M.
tuberculosis, e.g., while rebuilding an HVAC system that would connect
to an existing one that is in use. The standard is not intended to
cover employees involved in other construction operations where they
would not have occupational exposure to air which may reasonably be
anticipated to contain aerosolized M. tuberculosis (e.g., a crane
operator constructing a new wing of a hospital). The standard would
apply only to construction employees who would incur occupational
exposure to tuberculosis. Such a case might arise during maintenance
operations on an air system that carries air that may reasonably be
anticipated to contain aerosolized M. tuberculosis or during
renovation, repair, or alteration of areas of buildings that may
reasonably be anticipated to contain aerosolized M. tuberculosis. The
probability of exposure to M. tuberculosis during these activities may
be high and it is necessary, therefore, for employees performing the
work to wear respirators, receive medical surveillance and be protected
by the other provisions of the proposed TB standard. Employees of such
contractors are subject to the same levels of TB exposure and need the
same protection as other exposed employees. Therefore, OSHA proposes to
cover these employees under the TB standard and has included
construction within the standard's scope.
Thus, although the impact of the standard will be limited, OSHA
believes that construction should not be exempted from the proposed
standard. OSHA believes that a loophole would be opened in the
enforcement of the standard if construction were exempted. The
distinction between maintenance and construction is often an ambiguous
one. If construction were excluded, contractors, such as HVAC
contractors, might argue that their work is ``construction'' and that
they are not covered by the standard. By covering construction, this
ambiguity does not arise. This approach is consistent with that taken
in other standards (e.g., Ethylene Oxide, 29 CFR 1910.1047; Benzene, 29
CFR 1910.1028).
Several of the sectors covered by the proposed standard may be
utilizing volunteers for assistance in the workplace. Under the OSH
Act, OSHA is mandated to protect employees against workplace hazards.
Consequently, volunteers are not covered by OSHA standards because they
are not employees. However, employers should be aware that simply
labeling a person as a volunteer is not determinative of whether an
employer/employee relationship exists, if the person is compensated for
his or her services. Some states or localities may decide to extend the
protections of OSHA standards to volunteers; however, such action is
the independent decision of these jurisdictions and is not a
requirement of the OSH Act.
In addition, the proposed standard applies in situations when an
employer has part-time employees, or where employees of other employers
are working in a covered facility. These employees are covered by the
standard in the same manner as other employees who have occupational
exposure to tuberculosis. For example, they would be provided with the
same protections as full-time on-site employees, such as being included
in the exposure determination, being trained, being provided with
medical surveillance, and being issued respiratory protection if
necessary. With regard to employers who provide employees to other
employers (e.g., personnel providers, temporary help agencies, nurse
registries), a shared responsibility for worker protection exists
between the provider and the client or ``host'' employer. The safety
and health rights of temporary or ``leased'' or contracted employees
are the same as the rights of those who are employed directly by the
host employer. The host employer is generally responsible for safety
and health measures taken to address hazards that are an integral part
of the workplace the host employer controls. Where other employers are
involved, contractors or other ``providers,'' a joint employer-employee
relationship may exist in which both (or more) employers share
responsibility for the safety and health of the employees. OSHA's
concern is to assure that workers receive full protection under this
standard. Who provides which protections to the various employees may
be specified as a matter of contract or employment agreement existing
between the client/host and the contractor/provider. In a typical
arrangement, for example, the provider employer might provide the
generic training required by the standard and assure that proper
follow-up medical evaluation occurs after an exposure incident. Host
employers would typically control potential exposure conditions and
fulfill other requirements of the standard, such as site-specific
training and respiratory protection.
While the proposed standard covers a number of different work
settings, as described above, OSHA recognizes that many different types
of activities occur in these different settings. Thus, not all
provisions of the proposed standard would apply in each work setting.
The provisions that are required will vary to some degree, depending on
the type of activities done in the work setting. In order to give
employers guidance as to what provisions would be applicable in their
work setting, OSHA has developed a series of charts of the requirements
that are most likely to be applicable for the affected industries.
The following charts outline provisions that would be required for
employers covered under the scope of the proposed TB standard.
(Employers who qualify for the limited program as outlined under
Paragraph (b), Application, should consult Appendix A for applicable
provisions.) The charts are categorized either by the types of
infection control activities that may be common among different work
settings (e.g., early identification and transfer of individuals with
suspected or confirmed infectious TB) or by a particular occupational
work group (e.g., emergency medical services, home health care). These
charts are designed to give employers a guide to the regulatory text by
outlining the provisions of the proposed standard that are applicable
for various types of work settings. These charts summarize the general
responsibilities of a particular required provision. The regulatory
text should be consulted for more specific details on particular
provisions.
In addition, it should also be kept in mind that even though these
charts are categorized by the type of activities occurring at a
worksite, the categories do not necessarily always follow industry
lines (i.e., an employer under a specific industry sector may not
always fall under a particular category outlined in the following
charts). The charts are not designed to serve as a stand alone check
list for any one industry sector. Due to the varying activities that
may take place in work settings encompassed by an industry sector, the
charts may not account for every applicable provision in every work
setting. The charts are intended to provide general guidance as to what
[[Page 54237]]
OSHA anticipates to be applicable provisions. Therefore, it is
important that employers evaluate the types of activities occurring in
settings where their employees work to determine which of the
provisions of the proposed standard would be applicable. In order to
give employers guidance, OSHA has listed some of the types of industry
sectors that the Agency assumes are likely to fall under a particular
category, given OSHA's current understanding of the activities commonly
occurring in these work settings.
OSHA requests comments on these assumptions and on the charts, and
particularly, on how the charts can be made more user friendly and be
better organized to help serve as a guide for employers trying to
comply with the standard. The following charts are included:
Chart 1: What Would Be Required in Work Settings Where Individuals with
Suspected or Confirmed Infectious TB are Admitted or Provided Medical
Services?
Chart 2: What Would Be Required in Work Settings Where Early
Identification and Transfer Procedures are Used for Individuals with
Suspected or Confirmed Infectious TB?
Chart 3: What Would Be Required for Employers with Employees Who
Provide Services to Individuals Who Have Been Isolated or Otherwise
Confined Due to Having Suspected or Confirmed Infectious TB or Who Work
in Areas Where the Air Has Been Identified As Reasonably Anticipated to
Contain Aerosolized M. tuberculosis?
Chart 4: What Would Be Required for Home Health Care and Home-Based
Hospice Care?
Chart 5: What Would Be Required for Emergency Medical Services?
Chart 6: What Would Be Required for Clinical and Research Laboratories?
Chart 7: What Would Be Required for Personnel Services?
Chart 1: What Would Be Required in Work Settings Where Individuals with
Suspected or Confirmed Infectious TB Are Admitted or Provided Medical
Services?
OSHA anticipates that Hospitals will be the primary type of
facility falling under this category. In general, individuals requiring
isolation are transferred to hospitals that have isolation
capabilities. In addition, medical services such as diagnostic testing
for evaluating TB disease are performed in a hospital setting. This
category also covers work settings where high-hazard procedures are
performed, e.g., medical examiners' offices. (Laboratories are covered
in a later chart). However, there may be other work settings such as
correctional facilities or long-term care facilities for the elderly
that provide isolation or perform high-hazard procedures on individuals
with suspected or confirmed infectious TB. In these cases, employers at
these facilities would be required to comply with the provisions
outlined in this chart.
------------------------------------------------------------------------
What Would Be Required in Work Settings Where Individuals With Suspected
or Confirmed Infectious TB Are Admitted or Provided Medical Services?
-------------------------------------------------------------------------
(c) Exposure Control
(c)(1) Exposure Determination
(c)(2)(i) Written Exposure Control Plan including:
(A) the exposure determination
(B) procedures for providing information to occupationally
exposed employees about individuals with suspected or confirmed
infectious TB or air that may reasonably be anticipated to
contain aerosolized M. tuberculosis
(C) procedures for reporting exposure incidents
(c)(2)(iii):
(A) procedures for prompt identification of individuals with
suspected or confirmed infectious TB
(B) procedures for isolating and managing the care of
individuals with suspected or confirmed infectious TB (e.g.,
minimizing the time and number of employees entering an
isolation room)
(C) a list of high-hazard procedures
(D) a schedule for inspection, maintenance, and performance
monitoring of engineering controls
(c)(2)(iv) If the employer operates an onsite laboratory, the plan
must include a determination as to whether the facility should
operate at Biosafety Level 2 or 3 containment and document the need
for controlled access, anterooms, sealed windows, directional
airflow, measures to prevent the recirculation of lab exhaust air,
filtration of exhaust air and thimble exhaust connections.
(c)(2)(vi) Document the number of confirmed cases of TB if claiming
reduced responsibilities under paragraph (g)(3)(iii)(D)
(c)(2)(vii) The exposure control plan must be:
(A) accessible
(B) reviewed annually and updated whenever necessary
(C) available for copying by the Assistant Secretary and
Director upon request
(d) Work Practices and Engineering Controls
All provisions of paragraph (d) are applicable
(e) Clinical and Research Laboratories
If the facility operates an onsite laboratory, the additional
provisions under paragraph (e) must be followed (See Chart 6 for
Clinical and Research Laboratories)
(f) Respiratory Protection
(f)(1)(i) Provide respirators to employees who:
(A) enter isolation rooms or areas in use for TB isolation
(B) are present during the performance of procedures or services
for an individual with suspected or confirmed infectious TB who
is not masked
(C) transport an unmasked individual with suspected or confirmed
infectious TB within the facility
(D) repair, replace, or maintain air systems or equipment that
may reasonably be anticipated to contain aerosolized M.
tuberculosis
(E) work in an area where an unmasked individual with suspected
or confirmed infectious TB has been segregated or otherwise
confined
(f)(1)(iii) Provide respirators at no cost and assure that the
employee uses the respirator in accordance with this standard
(f)(1)(iv) Assure that the employee dons the respirator before
entering any of the work settings or performing any of the tasks
identified in paragraph (f)(1)(i) (A) through (E) and uses it until
leaving the work setting or the task has been completed
All remaining provisions of paragraph (f) are applicable, i.e.,
(f)(2)-(f)(8)
(g) Medical Surveillance
All provisions of paragraph (g) are applicable
(h) Communication of Hazards and Training
[[Page 54238]]
(h)(1)(i) Label air systems that may reasonably be anticipated to
contain aerosolized M. tuberculosis ``Contaminated Air--Respiratory
Protection Required''
(h)(1)(ii) If the employer operates an onsite laboratory, label
clinical and research laboratory wastes with the biohazard symbol
(h)(2)(i) Post signs at entrances to:
(A) isolation rooms or areas
(B) areas where procedures or services are being performed on an
individual with suspected or confirmed infectious TB
(C) clinical and research laboratories where M. tuberculosis is
present if the employer operates an onsite laboratory
(h)(2)(ii) Ventilate isolation rooms or areas vacated by individuals
with suspected or confirmed infectious TB, in accordance with
Appendix C, unless those individuals are medically determined to be
noninfectious
(h)(2)(iii) Signs must be readily visible and have a stop sign with
the legend ``No Admittance Without Wearing a Type N95 or More
Protective Respirator''
(h)(2)(iv) Signs at the entrances to clinical or research
laboratories (for employers who operate onsite laboratories) and
autopsy suites where procedures are being performed that may
generate aerosolized M. tuberculosis
(h)(3) Information and Training
All elements are applicable
(i) Recordkeeping
All recordkeeping is applicable
------------------------------------------------------------------------
Chart 2: What Would Be Required in Work Settings Where Early
Identification and Transfer Procedures Are Used for Individuals With
Suspected or Confirmed Infectious TB ?
OSHA anticipates that the types of establishments falling under
this category are likely to be long term care facilities for the
elderly, correctional facilities, immigration detainment facilities,
hospices, homeless shelters, substance abuse treatment centers, and
hospitals that do not admit individuals with suspected or confirmed
infectious TB. In these work settings, employers will use the signs and
symptoms of active TB as well as any other available information (e.g.,
tuberculin skin test status) to identify individuals with suspected or
confirmed infectious TB. These individuals will then be transferred to
facilities with appropriate isolation capabilities. Therefore,
facilities that transfer do not need to have engineering controls.
Temporary engineering controls will only be necessary in limited
situations where transfer cannot be accomplished within 5 hours.
------------------------------------------------------------------------
What Would Be Required in Work Settings Where Early Identification and
Transfer Procedures Are Used for Individuals With Suspected or Confirmed
Infectious TB?
-------------------------------------------------------------------------
(c) Exposure Control
(c)(1) Exposure Determination
(c)(2)(i) Written Exposure Control Plan including:
(A) the exposure determination
(B) procedures for providing information to occupationally
exposed employees about individuals with suspected or confirmed
infectious TB or air that may reasonably be anticipated to
contain aerosolized M. tuberculosis
(C) procedures for reporting exposure incidents
(c)(2)(ii) Employers who transfer individuals with suspected or
confirmed infectious TB must include in the plan: procedures for
prompt identification, masking or segregation, and transfer of such
individuals
(c)(2)(vi) Document the number of confirmed cases of TB if claiming
reduced responsibilities under paragraph (g)(3)(iii)(D)
(c)(2)(vii) The exposure control plan must be:
(A) accessible
(B) reviewed annually and updated whenever necessary
(C) available for copying by the Assistant Secretary and
Director upon request
(d) Work Practices and Engineering Controls
(d)(1) Use work practices and engineering controls to eliminate or
minimize employee exposure to M. tuberculosis
(d)(2) Implement the work practices in the Exposure Control Plan
(d)(3) Identify individuals with suspected or confirmed infectious
TB and:
(i) mask or segregate the individual until transfer can be
accomplished
(ii) place the individual in temporary isolation if transfer
cannot be accomplished within 5 hours from the time of
identification
(d)(5) Engineering controls (i.e., negative pressure, direct exhaust
or HEPA filtration, etc.) shall be used when temporary isolation is
used
(d)(6) Provide information about TB hazards to any contractor who
provides temporary or contract employees who will incur
occupational exposure
(f) Respiratory Protection
(f)(1)(i) Provide respirators to employees who:
(A) enter a temporary isolation room or area
(E) work in an area where an unmasked individual with suspected
or confirmed infectious TB has been segregated or otherwise
confined and is awaiting transfer
(f)(1)(iii) Provide respirators at no cost and assure that the
employee uses the respirator in accordance with this standard
(f)(1)(iv) Assure that the employee dons the respirator before
entering the work setting and uses it until leaving the work
setting
All remaining provisions of paragraph (f) are applicable, i.e.,
(f)(2)-(f)(8)
(g) Medical Surveillance
All provisions of paragraph (g) are applicable
(h) Communication of Hazards and Training
(h)(1)(i) Label air systems that may reasonably be anticipated to
contain aerosolized M. tuberculosis ``Contaminated Air--Respiratory
Protection Required'' if temporary isolation is used
(h)(2)(i)(A) Post signs at entrances to temporary isolation rooms or
areas
(h)(2)(ii) Ventilate temporary isolation rooms or areas vacated by
individuals with suspected or confirmed infectious TB in accordance
with Appendix C, unless those individuals are medically determined
to be noninfectious
(h)(2)(iii) Signs used for temporary isolation must be readily
visible and have a stop sign with the legend ``No Admittance
Without Wearing a Type N95 or More Protective Respirator''
[[Page 54239]]
(h)(3) Information and Training
All elements are applicable
(i) Recordkeeping
All recordkeeping is applicable
------------------------------------------------------------------------
Chart 3: What Would Be Required for Employers With Employees Who
Provide Services to Individuals Isolated or Otherwise Confined Due to
Having Suspected or Confirmed Infectious TB or Who Work in Areas
Identified as Reasonably Anticipated to Contain Aerosolized M.
tuberculosis?
OSHA anticipates that the type of employees falling under this
category will be workers providing social work services, social welfare
services, teaching, law enforcement or legal services to individuals
who are in isolation or confined to their homes due to having suspected
or confirmed infectious TB. Also included in this category are
maintenance employees such as contract HVAC maintenance employees who
work on air systems that have been identified as carrying air that may
reasonably be anticipated to contain aerosolized M. tuberculosis.
Employers in these situations will not need to perform early
identification procedures since the identification of individuals with
suspected or confirmed infectious TB has already been accomplished.
Similarly, air systems will already be labeled as containing
``Contaminated Air''.
------------------------------------------------------------------------
What Would Be Required for Employers with Employees Who Provide Services
to Individuals Isolated or Otherwise Confined Due to Having Suspected or
Confirmed Infectious TB or Who Work in Areas Identified as Reasonably
Anticipated to Contain Aerosolized M. tuberculosis?
-------------------------------------------------------------------------
(c) Exposure Control
(c)(1) Exposure Determination
(c)(2)(i) Written Exposure Control Plan including:
(A) the exposure determination
(B) procedures for providing information to occupationally
exposed employees about individuals with suspected or confirmed
infectious TB or air that may reasonably be anticipated to
contain aerosolized M. tuberculosis
(C) procedures for reporting exposure incidents
(c)(2)(vii) The exposure control plan must be:
(A) accessible
(B) reviewed annually and updated whenever necessary
(C) available for copying by the Assistant Secretary and
Director upon request
(d) Work Practices and Engineering Controls
(d)(1) Use work practices to eliminate or minimize employee exposure
to M. tuberculosis
(d)(2) Implement the work practices in the Exposure Control Plan
(d)(6) Provide information about TB hazards to any contractor who
provides temporary or contract employees who will incur
occupational exposure
(f) Respiratory Protection
(f)(1)(i) Provide respirators to employees who:
(A) enter isolation rooms or areas
(D) repair, replace or maintain air systems or equipment that
may reasonably be anticipated to contain aerosolized M.
tuberculosis
(F) work in a residence where an individual with suspected or
confirmed infectious TB is known to be present
(f)(1)(iii) Provide respirators at no cost and assure that the
employee uses the respirator in accordance with this standard
(f)(1)(iv) Assure that the employee dons the respirator before
entering the work setting and uses it until leaving the work
setting
All remaining provisions of paragraph (f) are applicable, i.e.,
(f)(2)--(f)(8)
(g) Medical Surveillance
All provisions of paragraph (g) are applicable
(h) Communication of Hazards and Training
(h)(3) Information and Training
All elements are applicable
(i) Recordkeeping
All recordkeeping, except for engineering controls records, is
applicable
------------------------------------------------------------------------
Chart 4: What Would Be Required for Home Health Care and Home-Based
Hospice Care?
In general, most of the provisions of the proposed standard would
be applicable for employers providing home health care or home-based
hospice care. However, OSHA realizes that home health care providers do
not have control over the home environment and therefore, the standard
would not require these employers to provide or maintain engineering
controls in the homes of their clients. OSHA also realizes that some
individuals with infectious TB may be sent home instead of being
admitted to the hospital; OSHA would not expect employers to transfer
such individuals out of their home. However, individuals with suspected
or confirmed infectious TB need to be identified so that home health
care providers can take appropriate precautions to protect themselves
while in the home.
------------------------------------------------------------------------
What Would Be Required for Home Health Care and Home-Based Hospice Care?
-------------------------------------------------------------------------
(c) Exposure Control
(c)(1) Exposure Determination
(c)(2)(i) Written Exposure Control Plan including:
[[Page 54240]]
(A) the exposure determination
(B) procedures for providing information to occupationally
exposed employees about individuals with suspected or confirmed
infectious TB or air that may reasonably be anticipated to
contain aerosolized M. tuberculosis
(C) procedures for reporting exposure incidents
(c)(2)(v) Employers who provide home health care or home-based
hospice care must include procedures for prompt ID of individuals
with suspected or confirmed infectious TB, procedures for
minimizing exposure to such individuals, a list of high-hazard
procedures performed, if any, and procedures for delaying elective
high-hazard procedures or surgery until the individual is
noninfectious
(c)(2)(vii) The exposure control plan must be:
(A) accessible
(B) reviewed annually and updated whenever necessary
(C) available for copying by the Assistant Secretary and
Director upon request
(d) Work Practices and Engineering Controls
(d)(1) Use work practices to eliminate or minimize employee exposure
to M. tuberculosis
(d)(2) Implement the work practices in the Exposure Control Plan
(d)(3) Identify individuals with suspected of confirmed infectious
TB
(d)(6) Provide information about TB hazards to any contractor who
provides temporary or contract employees who will incur
occupational exposure
(f) Respiratory Protection
(f)(1)(i) Provide respirators to employees who:
(F) work in a residence where an individual with suspected or
confirmed infectious TB is known to be present
(f)(1)(iii) Provide respirators at no cost and assure that the
employee uses the respirator in accordance with this standard
(f)(1)(iv) Assure that the employee dons the respirator before
entering the work setting and uses it until leaving the work
setting
All remaining provisions of paragraph (f) are applicable, i.e.,
(f)(2)-(f)(8)
(g) Medical Surveillance
All provisions of paragraph (g) are applicable
(h) Communication of Hazards and Training
(h)(3) Information and Training
All elements are applicable except those related to the use of
engineering controls
(i) Recordkeeping
All recordkeeping, except for engineering controls records, is
applicable
------------------------------------------------------------------------
Chart 5: What Would Be Required for Emergency Medical Services?
Similar to Home Health Care or Home-Based Hospice Care, employers
providing emergency medical services do not have control over many of
the work settings in which they may provide services. Thus, OSHA would
not require these employers to provide or maintain engineering
controls. In addition, while these types of employers are likely to be
transferring individuals with infectious TB, it is not their
responsibility to initiate the transfer of an individual identified as
having suspected or confirmed infectious TB to a facility with
appropriate isolation capabilities. However, where it is feasible to do
so, such individuals need to be identified so that emergency medical
service employees can take precautions to protect themselves.
------------------------------------------------------------------------
What Would Be Required for Emergency Medical Services?
-------------------------------------------------------------------------
(c) Exposure Control
(c)(1) Exposure Determination
(c)(2)(i) Written Exposure Control Plan including:
(A) the exposure determination
(B) procedures for providing information to occupationally
exposed employees about individuals with suspected or confirmed
infectious TB or air that may reasonably be anticipated to
contain aerosolized M. tuberculosis
(C) procedures for reporting exposure incidents
(c)(2)(iii):
(A) Procedures for prompt identification of individuals with
suspected or confirmed infectious TB
(B)(4) Procedure or policy for using properly-fitted masks on
individuals with suspected or confirmed infectious TB
(C) A list of high-hazard procedures
(c)(2)(vii) The exposure control plan must be:
(A) accessible
(B) reviewed annually and updated whenever necessary
(C) available for copying by the Assistant Secretary and
Director upon request
(d) Work Practices and Engineering Controls
(d)(1) Use work practices to eliminate or minimize employee exposure
to M. tuberculosis
(d)(2) Implement the work practices in the Exposure Control Plan
(d)(3) Identify individuals with suspected or confirmed infectious
TB
(d)(6) Provide information about TB hazards to any contractor who
provides temporary or contract employees who will incur
occupational exposure
(f) Respiratory Protection
(f)(1)(i) Provide respirators to employees who:
(A) enter an isolation room or area
(B) are present during the performance of procedures or services
for an individual with suspected or confirmed infectious TB who
is not masked
(C) transport an individual with suspected or confirmed
infectious TB in an enclosed vehicle or who transport an
unmasked individual with suspected or confirmed infectious TB
within the facility
(F) work in a residence where an individual with suspected or
confirmed infectious TB is known to be present
(f)(1)(iii) Provide respirators at no cost and assure that the
employee uses the respirator in accordance with this standard
(f)(1)(iv) Assure that the employee dons the respirator before
entering the work setting and uses it until leaving the work
setting
[[Page 54241]]
All remaining provisions of paragraph (f) are applicable, i.e.,
(f)(2)-(f)(8)
(g) Medical Surveillance
All provisions of paragraph (g) are applicable
(h) Communication of Hazards and Training
(h)(3) Information and Training
All elements are applicable except those related to the use of
engineering controls
(i) Recordkeeping
All recordkeeping, except for engineering controls records, is
applicable
------------------------------------------------------------------------
Chart 6: What Would Be Required for Clinical and Research Laboratories?
Employers in clinical and research laboratories that handle
specimens that may contain M. tuberculosis or process or maintain the
resulting cultures or perform activities that may result in the
aerosolization of M. tuberculosis must follow most of the provisions of
the proposed standard. In addition, a special paragraph has been added
to address the unique hazards of the lab environment. Clinical and
research labs are not responsible for developing or implementing
procedures for the early ID of individuals with suspected or confirmed
infectious TB or the transfer of those individuals.
------------------------------------------------------------------------
What Would Be Required for Clinical and Research Laboratories?
-------------------------------------------------------------------------
(c) Exposure Control
(c)(1) Exposure Determination
(c)(2)(i) Written Exposure Control Plan including:
(A) the exposure determination
(B) procedures for providing information to occupationally
exposed employees about individuals with suspected or confirmed
infectious TB or air that may reasonably be anticipated to
contain aerosolized M. tuberculosis
(C) procedures for reporting exposure incidents
(c)(2)(iv) Employers who operate a laboratory must include a
determination as to whether the facility should operate a
laboratory at Biosafety Level 2 or 3 containment and document the
need for controlled access, anterooms, sealed windows, directional
airflow, measures to prevent the recirculation of lab exhaust air,
filtration of exhaust and thimble exhaust connections
(c)(2)(vii) The exposure control plan must be:
(A) accessible
(B) reviewed annually and updated whenever necessary
(C) available for copying by the Assistant Secretary and
Director upon request
(d) Work Practices and Engineering Controls
(d)(1) Use work practices and engineering controls to eliminate or
minimize employee exposure to M. tuberculosis
(d)(2) Implement the work practices in the Exposure Control Plan
(d)(6) Provide information about TB hazards to any contractor who
provides temporary or contract employees who will incur
occupational exposure
(e) Clinical and Research Laboratories
All provisions of paragraph (e) are applicable
(f) Respiratory Protection
(f)(1)(ii) For research laboratories, provide respirators to
employees who are present when aerosols of M. tuberculosis cannot
be safely contained
(f)(1)(iii) Provide respirators at no cost and assure that the
employee uses the respirator in accordance with this standard
(f)(1)(iv) Assure that the employee dons the respirator before
performing the tasks under (f)(1)(ii) and uses it until completing
the tasks
All remaining provisions of paragraph (f) are applicable, i.e.,
(f)(2)-(f)(8)
(g) Medical Surveillance
All provisions of paragraph (g) are applicable
(h) Communication of Hazards and Training
(h)(1)(i) Labels:
(h)(1)(i) Label air systems that may reasonably be anticipated
to contain aerosolized M. tuberculosis ``Contaminated Air--
Respiratory Protection Required''
(h)(1)(ii) Label clinical and research laboratory wastes with
the biohazard symbol
(h)(2) Signs:
(h)(2)(i)(C) Post signs at entrances to clinical and research
laboratories where M. tuberculosis is present
(h)(2)(iv) Include on the sign the biohazard symbol, the name
and telephone number of the laboratory director or other
designated responsible person, the infectious agent designation
M. tuberculosis, and special requirements for entering the
laboratory
(h)(3) Information and Training
All elements are applicable
(i) Recordkeeping
All recordkeeping is applicable
------------------------------------------------------------------------
Chart 7: What Would Be Required for Personnel Services?
This category covers employers who provide temporary employees to
any of the other employers covered under the scope of the standard
(e.g., temporary nurses hired to work at a hospital, temporary lab
technicians working in a clinical laboratory). Employees in these
situations are covered by the standard in the same manner as other
employees who have occupational exposure to tuberculosis. A shared
responsibility for worker protection exists between the personnel
service employer and the client (or ``host'') employer. These matters
may be specified as a matter of contract or employment agreement
existing between the personnel service employer and the host employer.
In this chart OSHA has assumed that a typical contract or employment
agreement exists between the two employers with the personnel provider
accepting responsibility for the general requirements and the host
employer being responsible for site-specific measures. Therefore, the
personnel service provider is shown complying with non-site specific
provisions such as exposure determination, medical surveillance, and
non-site specific employee training. The host employer would comply
with more site-specific
[[Page 54242]]
provisions such as procedures for early ID, engineering controls and
site-specific employee training. In addition, the chart assumes that
the personnel service provider has accepted the responsibility for
respiratory protection. OSHA requires that workers in these situations
receive full protection under the standard.
------------------------------------------------------------------------
What Would Be Required for Personnel Services?
-------------------------------------------------------------------------
(c) Exposure Control
(c)(1) Exposure Determination
(c)(2)(i) Written Exposure Control Plan including:
(A) the exposure determination
(B) procedures for providing information to occupationally
exposed employees about individuals with suspected or confirmed
infectious TB or air that may reasonably be anticipated to
contain aerosolized M. tuberculosis
(C) procedures for reporting exposure incidents
(c)(2)(vii) The exposure control plan must be:
(A) accessible
(B) reviewed annually and updated whenever necessary
(C) available for copying by the Assistant Secretary and
Director upon request
(d) Work Practices and Engineering Controls
(d)(1) Use work practices to eliminate or minimize employee exposure
to M. tuberculosis
(d)(2) Implement the work practices in the Exposure Control Plan
(f) Respiratory Protection
All provisions of paragraph (f) are applicable
(g) Medical Surveillance
All provisions of paragraph (g) are applicable except those related
to conducting site-specific follow-up investigations after an
exposure incident or skin test conversion
(h) Communication of Hazards and Training
(h)(3) Information and Training
All elements are applicable except those training elements which
are site-specific
(i) Recordkeeping
All recordkeeping, except for engineering control records, is
applicable
------------------------------------------------------------------------
OSHA's preliminary conclusion is that all employees who have
occupational exposure to aerosolized M. tuberculosis, as a result of
performing their duties, are at risk of infection. Under paragraph (a)
the Agency has listed those facilities, work settings and services
where it believes that significant occupational exposure is most likely
to occur. OSHA requests comment and supporting data as to whether there
are other work settings or services where significant occupational
exposures can be reasonably anticipated.
Paragraph (b) Application
As discussed above, OSHA has preliminarily determined that there
are elevated risks of TB infection associated with certain types of
work settings and services. However, the Agency realizes that there may
be employers covered under the scope of the standard who have work
settings in counties where the risk of TB infection is low. Some
geographical areas in the U.S. have not reported cases of TB to CDC and
facilities in these areas have not encountered any individuals with
confirmed infectious TB in their work settings within the recent past.
In consideration of the lessened likelihood of employee exposure in
these work settings, OSHA is proposing that some employers be permitted
to qualify for a more limited program. Paragraph (b), Application,
states that an employer covered under paragraph (a), Scope, other than
the operator of a laboratory, may choose to comply only with the
provisions of Appendix A if the Exposure Control Plan demonstrates that
his or her facility or work setting: (1) does not admit or provide
medical services to individuals with suspected or confirmed infectious
TB; (2) has not encountered a case of confirmed infectious TB in the
past 12 months; and (3) is located in a county that, in the past 2
years, has had no cases of confirmed infectious TB reported in one year
and fewer than 6 cases of confirmed infectious TB reported in the other
year. Thus, in the past two year period, the number of reported TB
cases must be 0 for at least one of the two years. (It may even be zero
for both years). In the other year, the number of cases must be no
greater than 5. For example, if in the first year of the preceding two-
year period the number of reported cases was 0, but in the second year
there were 4 reported cases of confirmed infectious TB in the county,
an employer would still qualify for the limited program under paragraph
(b), provided that none of the cases were encountered in his or her
employees' work setting. However, for the employer in this scenario to
continue to qualify for the limited program, the number of cases
reported in the third year would have to return to zero. Similarly,
employers would not qualify for the limited program if the number of
cases of confirmed infectious TB reported in the county was greater
than zero in both of the preceding two years or if 6 or more cases were
reported in one of the preceding two years.
OSHA has taken this approach because the number of TB cases
fluctuates widely and different locations and geographical areas may be
affected at different times. For example, many counties report no cases
in one year or even in two consecutive years, or report a few cases in
one year but then have no cases in the following year. From 1992 to
1994 (Ex.7-262), 55.3 percent of the counties in the U.S., representing
12.9 percent of the population, reported no confirmed cases of TB in
one year of the preceding two-year period and fewer than 6 cases in the
other year. OSHA believes that the approach described above is
appropriate given these fluctuations and that it reduces the burden on
employers who rarely encounter TB cases by allowing them to qualify for
the limited program. OSHA initially considered allowing employers to
qualify for the limited program only if there had been no cases of
confirmed infectious TB reported in the county in the preceding one-
year period. This would have meant that an employer would be required
to comply with the full program if even a single case was reported in
the county in any year. OSHA requests comment on the approach taken in
the proposed rule and the appropriateness of the ``zero-county''
trigger used in the standard.
[[Page 54243]]
Although OSHA believes that the risk of incurring TB is
substantially reduced in facilities located in counties qualifying for
the limited program, the risk of infection continues because all
counties have residents who are infected and who may therefore develop
active TB and transmit it. In addition, the mobility of the U.S.
population means that it is easy to carry the disease from higher risk
areas to lower risk areas. Thus, OSHA believes that certain TB exposure
control provisions, i.e., those reflected in the limited program
required by the standard, need to be in place in all work settings
where cases of TB could be encountered.
Under the limited program, employers are responsible for (1)
preparing a written exposure control plan with certain minimal
elements, (2) providing a baseline skin test and medical history, (3)
making medical management and follow-up available after an exposure
incident, (4) providing medical removal protection if necessary, (5)
providing information and training to employees with potential
occupational exposure, and (6) complying with pertinent recordkeeping
requirements. The specific paragraphs of the proposed standard that
would apply in these situations are outlined in Appendix A.
OSHA believes that these provisions are the minimum requirements
necessary for employee protection, even in work settings where no TB
has recently been reported in the county and no individuals with
confirmed infectious TB have been encountered within the work setting
during the past 12 months. OSHA's reasoning is that, although no cases
of confirmed infectious TB have been reported for the preceding two
years, there is considerable fluctuation among counties from one year
to the next, as explained above. In addition, as discussed in the
preliminary risk assessment section of the preamble, there is a high
prevalence of TB infection nationwide, approximately 6.5 percent.
Infections may become active after a latency period of years.
Therefore, the absence of a reported active case in the immediate past
does not mean that active cases will not be manifested in the current
or subsequent years. For these reasons, it is necessary for covered
facilities to maintain, at a minimum, a TB program that incorporates
the basic TB exposure control provisions that will protect employees
from exposures.
A primary element of the limited program is a written exposure
control plan. The exposure control plan includes an exposure
determination to identify those employees who would incur occupational
exposure if an individual with infectious TB were encountered in the
work setting. The exposure control plan would also have to contain
procedures and policies for the early identification and masking of
individuals with suspected or confirmed infectious TB and procedures
for transferring those individuals to other facilities. This would
assure that if an individual with suspected or confirmed infectious TB
were to enter the workplace, he or she would be promptly identified and
transferred to a facility with AFB isolation capabilities. In addition,
while awaiting transfer, these individuals could be masked to the
extent that it is feasible (e.g., in the case of a non-combative
individual) in order to prevent transmission. Similarly, the exposure
control plan must include procedures for reporting exposure incidents
should they occur. Employees need to know what steps to take if an
exposure occurs so that appropriate follow-up can be initiated for the
medical management of the exposed employee and investigation of the
incident.
In order to qualify for the limited program pursuant to paragraph
(b), the employer must include in his or her exposure control plan the
number of TB cases reported in the county and the number of individuals
with confirmed infectious TB who have been encountered within the work
setting. An employer is required by the standard to check and document
the number of confirmed infectious TB cases in the county once a year.
Typically, county health departments collect this information for
reporting purposes and report it both on a monthly and an annual basis.
Obtaining the annual count from the county health department would meet
the requirements of the proposed rule. County case counts must be
recorded for the two most recent annual reporting periods, i.e., the
two preceding years. This count must be reflected in the employer's
Exposure Control Plan, as described below in paragraph (c), Exposure
Control Plan, of this Summary and Explanation. The count of cases and
the notation in the Plan can be kept in any media, e.g., paper or
electronic.
In addition to an abbreviated exposure control plan, the limited
program would include some of the basic elements of medical
surveillance, i.e., baseline skin tests and medical histories for
employees identified under the exposure determination and medical
management and follow-up for those employees who have had an exposure
incident. Baseline skin tests and histories will help to assure that
true conversions are appropriately identified should an exposure
incident occur. Medical management and follow-up provisions will assure
that exposed employees receive the proper medical evaluation after an
exposure incident and that the incident is properly investigated so
that it will not occur again. Under this limited program, no periodic
medical surveillance would be required.
Where necessary, the employer is also required to provide medical
removal and protection (MRP) of benefits for those employees who
develop active TB. OSHA anticipates that the need to provide MRP would
be a rare event because little active TB has been reported in many of
these counties. In addition, if employees are properly trained to
identify suspected and confirmed infectious TB and to promptly transfer
those individuals, few occupational exposures should occur, thus
minimizing the likelihood that employees will become infected.
Therefore, training is an important element of the limited program.
Training is a key element in assuring that employees know how to
identify individuals with suspected or confirmed infectious TB and the
necessary steps to take if such an individual is encountered.
Certain minimal records must also be kept by the employer. Medical
records for documenting baseline skin tests and any potential medical
evaluations made as a result of an exposure incident, as well as
records for training and records for OSHA illnesses and injuries, would
have to be kept. Keeping records should not be burdensome for the
employer since it is likely that only a minimal number of employees
would be identified by the exposure determination as having potential
occupational exposure (e.g., intake workers in admitting areas or
emergency departments); only such employees need medical surveillance
or training.
The elements of the limited program outlined under this paragraph
closely track the recommendations of the CDC for facilities designated
as having ``minimal risk'' under the CDC's TB Guidelines for Health
Care Facilities (Ex. 4B). Under these guidelines, CDC considers
facilities to have ``minimal risk'' if there is no TB in the community
and no TB in the facility. CDC's recommendations for such facilities
include a written TB control plan, procedures for early identification
and prompt transfer of individuals with suspected or confirmed
infectious TB, and employee training. CDC does not specifically
recommend baseline skin testing. However, CDC's guidelines do say that
baseline testing would be
[[Page 54244]]
advisable in these facilities so that, if an unexpected exposure does
occur, conversions can be distinguished from positive skin test results
caused by previous exposures. CDC also recommends that a risk
assessment be conducted by such facilities each year. In the case of a
``minimal risk'' facility, as defined by CDC, this would essentially
involve checking on the number of reported cases of TB in the community
and within the facility, which is essentially what OSHA requires under
the exposure control plan as documentation to qualify for the limited
program available under paragraph (b).
Paragraph (c) Exposure Control
Employees incur risk each time they are exposed to aerosolized M.
tuberculosis. A worker can become infected from a single exposure
incident, and thus it is necessary to prevent exposure incidents
whenever possible. The goal of this proposed standard is to reduce the
significant risk of infection by minimizing or eliminating occupational
exposure to aerosolized M. tuberculosis.
One purpose of paragraph (c), Exposure Control, is to identify the
tasks and procedures where occupational exposure may occur and to
identify those employees whose duties include these tasks and
procedures. An additional purpose of the paragraph is to develop and
document, in an exposure control plan, policies and procedures for
eliminating or minimizing occupational exposure, e.g., developing
procedures for identifying individuals with suspected or confirmed TB,
for appropriately isolating and minimizing employee contact with those
individuals, and for reporting exposure incidents.
Paragraph (c)(1) requires each employer who has an employee with
occupational exposure to prepare an exposure determination that
identifies those employees who have occupational exposure to
aerosolized M. tuberculosis. As discussed under paragraph (j),
Definitions, ``occupational exposure'' means ``reasonably anticipated
contact that results from the performance of an employee's duties, with
an individual with suspected or confirmed infectious TB or air that may
contain aerosolized M. tuberculosis.'' Thus, the exposure determination
needs to include, in addition to those employees who have direct
contact with individuals with suspected or confirmed infectious TB and
employees who perform procedures that may aerosolize M. tuberculosis,
those employees who can reasonably be anticipated as part of their job
duties to be exposed to air that may contain aerosolized M.
tuberculosis.
For example, while an admissions clerk in a homeless shelter will
not perform medical procedures on a client with suspected infectious
tuberculosis, the clerk may reasonably be anticipated to encounter and
share the same airspace with such an individual. Therefore, the
admissions clerk would be included in the Exposure Control Plan and
would be covered by this standard.
Exposure determination is a key provision of exposure control
because the employer must know which tasks or procedures involve
occupational exposure in order to determine what measures can be taken
to eliminate or minimize exposure incidents. In addition, an exposure
determination is necessary in order to ascertain which employees are to
be provided with respiratory protection, medical surveillance, and
training.
Each employer is required to consider the duties, tasks, and
procedures of all employees in each job classification in each work
area where occupational exposure occurs when making the exposure
determination. OSHA believes that it is appropriate to allow the
employer to identify and document job classifications where all or some
employees have occupational exposure as a basis for the required
exposure determination. By identifying the job classification, each
employee included in the description will know that he or she is within
the scope of the standard. Listing of every employee's name is not
required, however, because that may be burdensome for employers who
have many employees with occupational exposure.
The term ``job classification'' is used generically. During the
development of the Bloodborne Pathogens standard, commenters used
several terms (e.g., ``job category'', ``job responsibility'', ``job
title'', ``position description'') to identify and document employees
at risk in the exposure determination. OSHA sought to use a term that
would encompass all of these terms. Therefore, as in the Bloodborne
Pathogens standard, OSHA has chosen to use the term ``job
classification'' because it has the broadest application to facilities
of all sizes that use formal and less formal designations to classify
employees. Thus, the standard would allow employers to use existing job
titles, job descriptions, or other designations to identify those job
classifications in which occupational exposure occurs. OSHA solicits
comment on whether this term needs further defining in this paragraph
or in paragraph (j), Definitions.
The standard does not require that every task and procedure that
could result in occupational exposure be listed in the exposure control
plan, but instead gives the employer a choice in how to document the
exposure determination. Paragraph (c)(1)(i) states that the exposure
determination shall contain:
(A) A list of the job classifications in which all employees
have occupational exposure; and
(B) A list of the job classifications in which some employees
have occupational exposure, and a list of all tasks and procedures
(or groups of closely related tasks and procedures) that these
employees perform and that involve occupational exposure.
This means that the employer may choose to extend ``blanket'' coverage
to those job classifications where essentially all employees have
occupational exposure [the paragraph (c)(1)(i)(A) option]. In this
case, the employer would not have to list all tasks and procedures for
those employees in the exposure control plan, since all of these
employees would be covered by the standard. For example, if a hospital
determines that all employees within the job classification
``respiratory therapist'' have duties or responsibilities that involve
tasks and procedures where occupational exposure occurs, the job
classification ``respiratory therapist'' can simply be listed in the
exposure determination in accordance with paragraph (c)(1)(i)(A) and no
subsequent listing of those tasks and procedures is required.
Similarly, the job classification of ``homeless shelter admissions
clerk'' in the previous example could be included under the ``blanket''
job classification list in paragraph (c)(1)(i)(A).
On the other hand, the employer may determine that job
classifications exist in which only some employees have occupational
exposure. The employer may determine that it is not necessary to
include all employees in such job classifications under the standard
since only a portion of them have occupational exposure. In these
situations [paragraph (c)(1)(i)(B)], the employer must list the job
classification as well as the tasks and procedures or groups of closely
related tasks and procedures performed by employees within that job
classification that result in occupational exposure. For example,
within the job classification ``laboratory technician,'' there may be
some employees who experience occupational exposure (e.g., laboratory
technicians who perform microbiological procedures on M. tuberculosis
cultures), while others would not be expected to
[[Page 54245]]
have such exposure (e.g., laboratory technicians who work in clinical
chemistry). In such a case, the employer may not wish to extend
coverage to all employees in the job classification ``laboratory
technician''. Consequently, the job classification ``laboratory
technician'' would be listed in the exposure determination along with
the tasks and procedures in which occupational exposure occurs. This
approach would inform employees within the job classification
``laboratory technician'' about those tasks that they perform that
involve occupational exposure and that employees performing those tasks
and procedures triggers their inclusion in the scope of the standard.
However, it would not be necessary for the employer to list each
procedure performed by a ``laboratory technician''. For example,
performing sputum smears, culturing the bacteria in the sputum, and
conducting drug-susceptibility testing on the culture all involve
manipulation of specimens that could contain M. tuberculosis.
Therefore, these tasks could be grouped under the designation
``manipulation of specimens that may contain M. tuberculosis.''
Although the standard permits the exposure determination to list
job classifications, grouping job classifications according to location
would not be sufficient to meet the requirement for identifying job
classifications with occupational exposure. For example, identifying
job classifications by using the ``Emergency Department'' would not
fulfill this requirement because it does not identify the specific
employee job classifications that have occupational exposure. An
employer who has determined that employees in the ``Emergency
Department'' warrant coverage under the standard would have to list the
job classifications that involve occupational exposure and identify the
tasks and procedures that result in occupational exposure. OSHA
believes that merely grouping employees by location, e.g., designating
all employees who work in the Emergency Department, may exclude
employees who have occupational exposure since such a grouping could
overlook employees who may occasionally enter the Emergency Department
but are not routinely assigned there. OSHA seeks comment about the
protectiveness of permitting exposure determinations to be made by
location within a work setting in certain specific instances where the
employer believes such a delineation is useful and will not misclassify
employees and specifically requests examples of regulatory language
that could achieve these objectives.
Paragraph (c)(1)(ii) requires that the exposure determination be
made without regard to the use of respiratory protection. It has been
OSHA's long-standing position that the determination of occupational
exposure be made without regard to the use of personal protective
equipment such as respirators. The reason for this is that several
conditions must be met for respiratory protection to effectively lessen
exposures. First, the employee must be trained to use the equipment
properly. Second, respiratory protection must be used each time the
task requiring such protection is performed. Third, respiratory
protection must fit properly. If even one of these conditions is not
fully met, protection cannot be assured. Therefore, all tasks that
entail occupational exposure need to be included in the exposure
determination, regardless of the use of respiratory protection. This
approach is consistent with other OSHA standards (e.g., Bloodborne
Pathogens, 29 CFR 1910.1030; Formaldehyde, 29 CFR 1910.1048; Cadmium,
29 CFR 1910.1027) and is essential to designing an appropriate exposure
control program. Utilizing this approach assures that workers who
perform tasks requiring respiratory protection will receive the
training, medical surveillance, and other provisions of this standard
that will enhance their safety should respiratory protection fail.
Paragraph (c)(2) requires that each employer covered under the
scope of the standard establish a written exposure control plan. The
exposure control plan is a key provision of the standard because it
requires the employer to identify the employees who receive training,
respiratory protection and medical surveillance and to develop a number
of policies and procedures that will eliminate or minimize employees'
exposure to sources of aerosolized M. tuberculosis. However, because
not all employers' work settings are the same, not all employers'
exposure control plans will need to contain the same elements. The goal
of the exposure control plan is to address the type of exposure that
occurs in a given work setting, as identified under the exposure
determination, and then to develop procedures and policies to minimize
or eliminate that exposure. Thus, the size and complexity of the
exposure control plan will be relative to the types of exposure
encountered in the employer's work setting. For example, social service
employees who must provide services to individuals who are in AFB
isolation are covered under the scope of the standard. The employer in
this case would only have to include certain minimal elements in his or
her exposure control plan. This employer would not have to include
elements for identifying individuals with suspected or confirmed
infectious TB since these individuals will already have been identified
by someone else. Similarly, the exposure control plan of such employers
would not have to include procedures for isolating or managing the care
of individuals with infectious TB. On the other hand, hospitals that
admit or provide medical services to individuals with suspected or
confirmed infectious TB would be required to have a more extensive
exposure control plan since the employer in this case would be
responsible for identifying, isolating and possibly performing high-
hazard procedures on individuals with suspected or confirmed infectious
TB.
Under paragraph (c)(2)(i), the proposed standard requires that the
exposure control plan be written. There are several reasons for having
the plan in writing. First, because exposure control must be practiced
by everyone--employee and employer--it is imperative that an employee
be able to find out what provisions are in place in his or her
workplace. In addition, the exposure determination gives an employee
who may be unfamiliar with the job a ready reference for ascertaining
which job classifications, tasks, and procedures entail occupational
exposure. Second, the exposure control plan also serves as an on-site
adjunct to the overall infection control plan for the work setting and
reinforces the employer's training program. Employees will be trained
about the various procedures developed by the employer to eliminate and
minimize exposure. Having the procedures written and available at the
work site will provide a ready reference for employees and will serve
as an adjunct to their training. Third, having the plan in writing is
also important for enforcement purposes. By reviewing the exposure
control plan, an OSHA compliance officer will be able to become
familiar with the employer's determination of tasks and procedures with
occupational exposure, the job classifications whose duties include
those identified tasks, and the policies and procedures the employer
uses to minimize occupational exposure along with any revisions to the
exposure control plan.
OSHA realizes that many workplaces covered under the scope of the
proposed standard may already have comprehensive infection control
plans
[[Page 54246]]
that may include many of the measures required by the proposed
standard. It is not OSHA's intent for employers to duplicate current
infection control plans solely for the purpose of complying with the
standard. Therefore, the exposure control plan may be comprised of
existing documents that are part of a larger infection control plan.
However, all elements of the exposure control plan for TB required by
the proposed standard must be included. In addition, the plan must be
in some manner a cohesive entity by itself or a guidance document must
exist that states the overall policy goals and directs the reader to
the location of the separate documents that are being used to fulfill
the requirements of the standard.
While there will be differences in the elements of employers'
exposure control plans, each employer covered under the scope of the
standard must have certain minimal elements in his or her plan.
Paragraphs (c)(2)(i)(A) through (c)(2)(i)(C) contain the minimal
elements that must be included in the exposure control plans of every
employer covered under the scope of the standard. Paragraph
(c)(2)(i)(A) requires that the exposure control plan must include the
exposure determination required under paragraph (c)(1). As discussed
above, the exposure determination is necessary to identify those
employees who have occupational exposure so that the employer can
determine which employees are to be given respiratory protection,
medical surveillance and training.
Paragraph (c)(2)(i)(B) requires that the employer develop
procedures for informing occupationally exposed employees about
suspected or confirmed infectious TB cases and about air that may
reasonably be anticipated to contain aerosolized M. tuberculosis in
order that the employees can take proper precautions against M.
tuberculosis exposure. Once individuals with suspected or confirmed
infectious tuberculosis have been identified, it is necessary to convey
this information to employees who may be exposed so that they may take
the steps necessary to eliminate or minimize their exposure. When
patient confidentiality may be a concern, it is not necessary to use an
individual's name to satisfy this provision. For example, lists do not
need to be made of all patients in the hospital with active TB.
Information may be conveyed to employees by simply labeling the
isolation room with the warning sign required under paragraph
(h)(2)(iii) while the room is in use for TB isolation. Labeling the
room will inform the employees that the individual in the room is in
respiratory isolation and the employee must stay out of the room or don
the appropriate respiratory protection before entering. Another
scenario in which such notification is necessary would be when such an
individual must be transported to another facility in an ambulance. In
this case, the employees who will be present in the ambulance would
have to be notified so that they could utilize proper precautions
during the transport.
Paragraph (c)(2)(i)(C) requires that the employer include in the
exposure control plan procedures for reporting exposure incidents,
including identification of the person to whom the incident is to be
reported, and the procedures the employer will use for evaluating the
circumstances surrounding exposure incidents as required by paragraph
(g)(4)(iv). Under paragraph (j), Definitions, an exposure incident * *
* is defined as
* * * an event in which an employee has been exposed to an
individual with confirmed infectious TB or to air containing
aerosolized M. tuberculosis without the benefit of all applicable
exposure control measures required by this section.
In the event that unprotected employees are exposed to aerosolized
M. tuberculosis, it is necessary that this exposure incident be
reported to the employer as soon as feasible in order to promptly
initiate proper medical management and follow-up of the exposed
employee. In addition, quick reporting of exposure incidents permits
the employer to investigate the circumstances surrounding such
incidents while pertinent conditions remain relatively unchanged and
are fresh in the employee's memory.
Procedures need to be in place describing how the exposure incident
is to be investigated. Having investigation procedures in place
beforehand will help to assure that such investigations are able to be
done promptly and in a consistent and thorough manner from case to
case. This will assist the employer in complying with the requirement
of paragraph (g)(4)(iv) that directs the employer to investigate and
document the circumstances surrounding the exposure incident to
determine if changes can be instituted that will prevent similar
occurrences in the future.
Paragraph (c)(2)(ii) applies to employers who transfer individuals
with suspected or confirmed infectious TB to a facility with AFB
isolation capabilities. This would apply to employers who operate a
facility from which an individual with suspected or confirmed
infectious TB is transferred and would not apply to employers whose
employees provide certain services such as social welfare services to
individuals who have been isolated and in settings where home health
care and home hospice care is provided.
The standard does not require any employer to transfer individuals
with suspected or confirmed infectious TB. Transfer is an option that
employers have that relieves the employer of many provisions of the
standard, such as AFB isolation rooms. If an employer chooses to use
the transfer option, the employer must include the procedure for
implementing the transfer in the exposure control plan.
Paragraph (c)(2)(ii) requires employers who transfer individuals
with suspected or confirmed infectious TB to develop exposure control
plan procedures that address the following: (1) prompt identification
of individuals with suspected or confirmed infectious TB; (2) masking
or segregation of individuals with suspected or confirmed infectious
TB; and (3) transfer of such individuals to a facility with AFB
isolation capabilities.
One of the most important steps in preventing TB transmission is
the early detection of individuals who may have infectious TB (Exs. 3-
33, 3-34, 3-35, 4B). It is essential that individuals with suspected or
confirmed infectious TB be identified as soon as possible so that
employees who must have contact with them will be warned early and be
able to use appropriate infection control practices to protect
themselves from exposure. Obviously, the sooner this is done, the less
occupational exposure there will be and the less likely that TB will be
transmitted. In addition, early identification of individuals with
suspected or confirmed infectious TB will allow for the timely transfer
and initiation of effective treatment of those individuals for whom the
diagnosis of TB is likely. By promptly administering effective
treatment, these individuals can be rendered noninfectious, thus
decreasing the time they are infectious and their potential for
exposing employees and other people.
OSHA is proposing that employers develop a procedure for the prompt
identification of individuals with suspected or confirmed infectious TB
as part of the exposure control plan. In order to assure prompt
identification, it is necessary for the employer to have procedures in
place regarding how this identification will be made. CDC has
recommended that identification procedures be based on the prevalence
and characteristics of TB in the population served by the specific
facility (Ex. 4B). For example,
[[Page 54247]]
individuals who come from communities with a high prevalence of TB and
exhibit certain signs of TB may be more highly suspected as having
infectious TB than individuals from communities with a low prevalence
of TB. OSHA, therefore, expects that the procedures may be different
depending upon the local conditions.
The procedure needs to contain the following:
Methodology--The employer must describe how he or she will make the
determination that an individual should be considered as having
suspected or confirmed infectious TB. There are several ways of doing
this. The employer can use information provided by a physician or other
health care provider in advance of an individual's admission to the
employer's facility that the individual has been diagnosed with
suspected or confirmed infectious TB. If this is not available the
employer must determine whether an individual should be considered as
having suspected infectious TB. OSHA defines suspected infectious TB
as:
* * * a potential disease state in which an individual is known,
or with reasonable diligence should be known, by the employer to
have one or more of the following conditions, unless the
individual's condition has been medically determined to result from
a cause other than TB: (1) to be infected with M. Tuberculosis and
to have the signs or symptoms of TB; (2) to have a positive acid-
fast bacilli (AFB) smear; or (3) to have a persistent cough lasting
3 or more weeks and two or more symptoms of TB, e.g., bloody sputum,
night sweats, anorexia, weight loss and fever. An individual with
suspected infectious TB has neither confirmed infectious TB nor has
he or she been medically determined to be noninfectious.
Although the definition specifies the criteria the employer must
incorporate in his or her plan, the employer will still need to
exercise judgment in determining whether an individual meets one or
more prongs of the definition. Of course, an employer, such as one who
operates a facility in an area of particularly high TB prevalence, is
free to use more stringent (i.e., additional) criteria for considering
an individual to have suspected infectious TB in his or her particular
work setting.
In situations where a medical diagnosis is not available either
before or at the time of admission, an employer must collect the
information he or she needs to make the determination. This can be
accomplished in two ways. The employer can have an employee administer
a medical history questionnaire to individuals seeking services from
the facility. Another way to obtain information to make this
determination is by having an employee observe the individual to
ascertain his or her health status, looking for the signs, and asking
about the symptoms included in OSHA's definition that may indicate
infectious TB. Many employers will use both questionnaires and
observation. The employee collecting the information will have to be
trained on how to conduct the investigation effectively and with
respect for the privacy of the individual.
Responsibilities--The employer must designate responsibilities for
determining whether an individual should be considered as having
suspected or confirmed infectious TB. However, all employees need to be
given clear instructions regarding their roles in the prompt
identification of suspected or confirmed infectious TB cases. For
example, the health care workers who are the first points of contact in
ambulatory care settings and emergency rooms in hospitals could be
involved with the initial screening of patients. They may be given
several questions to ask a patient, which would be used as information
to begin the determination. The next actions would depend upon the
responses, and the authority of the health care workers. Some
employees, for example, would only report answers to questions or their
observation of signs of infectious TB in the client population to
someone more knowledgeable. Other employees would be making
determinations. The hospital would probably have a different procedure
that would be used before or at admission to the hospital for scheduled
services. The same hospital might have still another procedure
designating responsibility to other employees for identifying patients
who develop TB while in the hospital. The Exposure Control Plan must
designate those employees who make the determination as to whether an
individual has suspected or confirmed infectious TB. An employer should
consider such designation(s) carefully because, regardless of who
determines that an individual has suspected infectious TB, it is the
employer who is responsible for ensuring that the employee knows and
uses the proper criteria.
The identification procedures will likely vary among
establishments, depending upon the type of work done in the facility.
For example, facilities that provide long-term care for the elderly
will likely have a different procedure from hospitals that have an open
admissions policy. OSHA also expects that the methods different
employers use may vary depending on whether the employer is in an area
of high or low TB prevalence. This approach is consistent with CDC
recommendations.
Promptness--Prompt identification of an individual with suspected
or confirmed infectious TB is important because it allows isolation
before the disease is spread through the facility. CDC recommends that
procedures be in place for prompt identification. However, OSHA expects
that the determination will be made as soon as reasonably practical
since an employer cannot always make such a determination immediately.
For many situations, such as those occurring in a hospice, the employer
will have information regarding an individual's health status prior to
admitting the individual to the facility. The employer can use this
information to determine whether the individual should be considered as
having suspected or confirmed infectious TB. In a long-term health care
facility, the employer needs to be continually aware of each resident's
health status because it can change rapidly. Information regarding the
signs or symptoms suspected infectious TB needs to be reported and
processed as soon as possible.
Effectiveness--OSHA believes that an effective procedure, when
implemented, will identify individuals as having suspected or confirmed
infectious TB. OSHA believes that many employers affected by this
proposed standard currently use effective procedures and find them to
be practical. However, OSHA also recognizes that it will not be
possible to ensure that the identification procedure will promptly
detect all individuals with infectious TB each time. In homeless
shelters, for example, the clients may withhold information requested
in a questionnaire because they believe that such information may
persuade the shelter to refuse to admit them. Therefore, homeless
shelters may have to place greater reliance on observation of the
residents for the cluster of signs and symptoms associated with
infectious TB. Although this standard would require that homeless
shelter workers and others be trained to look for signs in individuals,
it is unlikely that all cases will be identified. However, if the
employer finds that individuals with suspected and confirmed infectious
TB are not being identified, the employer must investigate in order to
determine what procedures need to be modified. During an inspection, an
OSHA compliance officer will review the adequacy of the procedures, and
although a citation would not be issued solely on the basis of failure
to identify an individual with suspected infectious TB because no
identification system is fool-proof,
[[Page 54248]]
failure to identify a number of individuals with undetected suspected
or confirmed infectious TB would be good evidence that the procedures
or their implementation need to be investigated and improved and could
result in a citation.
The employer must also include in the exposure control plan
procedures for transferring individuals with suspected or confirmed
infectious TB to facilities with AFB isolation capabilities. The
procedures must address how those transfers are to take place in order
that the transfers may be conducted promptly and with minimal exposure
to employees. Specifically, they will include where the cases are to be
transferred, how the transfer will occur, and what precautions
employees are to take while individuals with suspected or confirmed TB
are awaiting transfer.
As the note to paragraph (c)(2)(ii) states, an employer's duties
regarding transfer of an individual with suspected or confirmed
infectious TB will vary with the type of facility the employer operates
and the work performed by his or her employees. For example, the
transfer responsibilities of hospitals, long-term care for the elderly,
correctional facilities, and hospices may include contacting the
receiving facility, providing transport, and taking other steps to
ensure the individual can get to the receiving facility. These types of
facilities often exercise custodial care over such individuals and,
hence, have more responsibility for assuring completion of the
transfer. Conversely, the responsibilities a homeless shelter or a
facility that offers drug treatment for drug abuse, but that does not
have custody over individuals, may only include providing information
about the receiving facility, contacting the facility, and providing
directions to the facility. An employer who provides home health care
or home-based hospice care has no obligation to transfer an individual
from his or her home to a receiving facility. Transferring an
individual with suspected or confirmed infectious TB protects employees
within the facility by making sure the source of occupational exposure
is removed and, of course, benefits the individual in that he or she
receives help in locating and getting to a receiving facility with the
capability for appropriately managing their care.
Paragraph (c)(2)(iii) outlines the additional elements required of
employers who have work settings where individuals with suspected or
confirmed infectious TB are admitted or provided with medical services.
Paragraph (c)(2)(iii)(A) requires that their exposure control plans
include procedures for the prompt identification of individuals with
suspected or confirmed infectious TB. As discussed above, the early
identification of individuals with infectious TB will help to assure
that employees who must have contact with those individuals will be
warned early and be able to use appropriate infection control practices
to protect themselves from exposure. In addition, for employers who
have facilities where individuals with suspected or confirmed
infectious TB are admitted and provided medical services, prompt
identification is essential so that isolation precautions and effective
treatment can be initiated as soon as possible, thereby reducing
exposure to employees and other people.
Paragraph (c)(2)(iii)(B) requires that the employer develop
procedures for isolating and managing the care of individuals with
suspected or confirmed infectious TB. Having isolation procedures in
place will help to assure that employees are aware of the steps to take
in the event that individuals with suspected or confirmed infectious TB
are identified. If employees know the proper procedures to follow, they
will be better equipped to initiate isolation promptly, thereby
reducing the likelihood that individuals with infectious TB will infect
others. This provision is in accordance with the most recent CDC
guidelines, which also recommend the procedures include:
(1) The indications for isolation, (2) who is authorized to initiate
and discontinue isolation, (3) isolation practices, (4) monitoring
of isolation, (5) management of patients who will not comply with
isolation practices, and (6) criteria for discontinuing isolation.
(Ex. 4B)
While OSHA allows the employer to determine what criteria should be
included in the procedures to isolate, the Agency believes that it is
prudent for the employer also to consider the elements listed in the
CDC guidelines.
Paragraph (c)(2)(iii)(B) also requires that the employer develop
policies and procedures for managing the care of individuals with
suspected or confirmed infectious TB once they have been placed in
isolation. The exposure control plan must include procedures and
polices addressing: (1) Minimization of the time an individual with
suspected or confirmed infectious TB remains outside of an AFB
isolation room or area, (2) minimization of employee exposure in AFB
isolation rooms or areas, (3) delay of elective transport or relocation
of individuals with infectious TB within the facility and, to the
extent feasible, performance of services or procedures for such
individuals in an AFB isolation room or area, (4) masking of
individuals with infectious TB or use of portable containment
engineering controls during transport outside of AFB isolation rooms
and return of the individual to an AFB isolation room or area as soon
as is practical after completion of the service or procedure, and (5)
delay of elective high-hazard procedures and elective surgery until an
individual with suspected or confirmed infectious TB is determined to
be noninfectious.
It is important to minimize, to the extent feasible, exposure of
employees to aerosolized M. tuberculosis even while maintaining a high
quality of health care and other required services. Developing policies
and procedures addressing the items listed above will help to assure
that this overall goal is met. For example, there may be times when an
individual with suspected or confirmed infectious TB must leave the
isolation room or area (e.g., when certain equipment necessary for
providing care to the patient cannot be brought into the room). On
these occasions having policies in place that minimize the time those
individuals must be outside the isolation room or area will help to
reduce the likelihood that droplet nuclei are spread. For example, if a
particular procedure must be performed outside of the isolation room,
time could be minimized by taking the individual directly to the
procedure area, performing the procedure upon arrival, and returning
the individual to isolation immediately after completion of the
procedure. In addition, if a procedure is to be performed outside of
the isolation room, a time could be chosen when the procedure area is
not being used by others.
The exposure control plan must also contain procedures for
minimizing employee exposure in AFB isolation rooms or areas. For
example, policies addressing minimizing both the number of employees
and time that such employees spend in isolation rooms can reduce
exposure. This can be accomplished in a variety of ways. For example,
in order to minimize the number of employees entering an isolation
room, certain tasks or procedures that might normally be done by
several different employees could be done by one person. A nurse coming
into the room to administer daily TB treatment could also bring in the
patient's breakfast at the same time rather than have a hospital
dietician deliver the meal. In addition, the
[[Page 54249]]
employer must address minimization of time that employees spend in an
isolation room or area. For example, rather than conducting an entire
discharge planning interview with an individual in person, the employee
may be able to collect and convey a large part of the information over
the phone with the individual. Personal contact could be limited to
just the time needed to obtain items requiring direct interaction, such
as the individual's signature.
Policies are to be included that address the masking of individuals
with infectious TB during transport outside of AFB isolation rooms or
areas. Masking of individuals may be accomplished, for example, through
the use of surgical masks or valveless respirators. A barrier such as a
surgical mask, when placed over the mouth of an individual who is
coughing, will reduce the formation of droplet nuclei because the mask
will collect and contain the droplets as they are discharged before
they have time to evaporate and form droplet nuclei. A respirator that
does not have an exhalation valve can also be used to capture droplets
being discharged. An exhalation valve would permit droplets to pass
through and discharge into the air, where they could evaporate and form
droplet nuclei. However, while surgical masks prevent the formation of
droplet nuclei, they do not prevent exposure to droplet nuclei. As the
document ``Biosafety Precautions for Airborne Pathogens'' states:
There is no reciprocity between the means of prevention of the
actual formation of droplet nuclei (coughing into a tissue) and the
means of prevention of exposure (barriers to breathing in the
droplet nuclei). Once a droplet nucleus has been allowed to form,
its small size can penetrate the fiber of a tissue or a surgical
mask. Thus these products do not represent adequate physical
barriers to the aerosol transmission of droplet nuclei. The
appropriate barrier is a well fitted respirator that does not allow
leakage of air around the edges and blocks passage of microorganisms
in the filter media (fibers or pores) through which air is inspired.
Although a simple surgical mask applied to a tuberculosis patient
who must be transported outside the isolation room will prevent the
dispersal of organisms as droplet nuclei, such a mask does not
provide adequate protection to the individual who must breathe air
containing droplet nuclei. (Ex. 7-134)
Since masking of an individual with suspected or confirmed
infectious TB will reduce the number of droplet nuclei expelled into
the air, the employer is required to develop policies addressing the
masking of such individuals during transport outside of an AFB
isolation room.
It is not OSHA's intent to dictate patient management practices,
nor will it be the Compliance Officer's responsibility to determine the
correctness of certain patient management policies. However, the Agency
believes that the employer must consider the above situations and
develop policies that address them, keeping in mind the goal of
minimizing employee exposure. This provision is in accordance with CDC
recommendations (Ex. 4B).
The exposure control plan must also contain policies for the delay
of elective transport or relocation within the facility of individuals
with suspected or confirmed infectious TB outside of an AFB isolation
room or area. For example, delaying the transfer of an inmate with
suspected or confirmed infectious TB from one prison to another, where
possible, until the inmate has been determined to be noninfectious,
will reduce not only the number of employees exposed, but will also
minimize the exposure of other inmates, thereby decreasing the risk of
transmission of disease.
Similarly, the exposure control plan is to include policies for the
delay of elective high-hazard procedures until an individual with
suspected or confirmed infectious TB has been determined to be
noninfectious. Elective high-hazard procedures (e.g., pulmonary
function testing) or elective surgery (e.g., noncritical dental
procedures) might be easily delayed, without compromising care, until
an individual with infectious TB has been determined to be
noninfectious.
Paragraph (c)(2)(iii)(C) requires the employer to list all high-
hazard procedures performed in the workplace. As discussed in paragraph
(j), Definitions, high-hazard procedures are defined as ``* * * those
procedures performed on an individual with suspected or confirmed
infectious tuberculosis in which the potential for being exposed to M.
tuberculosis is increased due to the reasonably anticipated generation
of aerosolized M. tuberculosis * * *'' Under paragraph (d)(4) of Work
Practice and Engineering Controls, the proposed standard requires that
all employers assure that high-hazard procedures are conducted in an
AFB isolation room or area. Thus, listing the high-hazard procedures
will serve to identify those procedures that require special
ventilation considerations (e.g., maintaining negative pressure and
properly exhausting contaminated air). This will assist employees in
determining which procedures must be performed using such engineering
controls and, consequently, will help minimize employee exposure.
For employers who have work settings where TB cases are isolated,
paragraph (c)(2)(iii)(D) requires the employer to develop a schedule
for the inspection, maintenance, and performance monitoring of
engineering controls. Engineering controls required by the proposed
standard play an essential role in reducing employee exposures to M.
tuberculosis. Thus, it is necessary that these controls be
appropriately maintained, inspected and monitored in order to assure
that they are functioning properly. Since engineering controls are
mechanical systems, they are prone to occasional lapses in performance
caused by occurrences such as clogged filters, slipping or broken drive
belts, burned-out motors, obstructed ducts, and so forth. Since these
situations cannot be predicted, it is necessary to regularly inspect
engineering controls for proper functioning. Hence, a schedule must be
developed for such activities. In addition, employees who are
responsible for the maintenance will have a record that they can check
to see when certain engineering controls need to be inspected,
maintained or monitored. In general, OSHA has left the time frame for
these activities up to the employer, except as required under
paragraphs (d)(5)(ii) and (d)(5)(iii), since the employer is familiar
with the characteristics of the workplace that could affect the
performance of these controls (e.g., dusty conditions, high heat and
humidity, seasonal variations).
For facilities with clinical or research laboratories, Paragraph
(c)(2)(iv) requires that the exposure control plan contain a
determination from the director of the laboratory as to whether the
laboratory facility should operate at Biosafety Level 2 or 3
containment according to CDC/NIH recommendations. Under paragraph (e),
Clinical and Research Laboratories, the proposed standard requires a
number of provisions to eliminate or minimize exposure in clinical and
research laboratory settings. These provisions are based on CDC/NIH
recommendations (Ex. 7-72) for laboratory procedures performed under
Biosafety Levels 2 and 3 for an infectious agent such as M.
tuberculosis. However, as noted in the CDC/NIH recommendations, the
selection of a biosafety level depends on a number of factors and it
may be necessary to adapt the biosafety level based upon such factors.
For example, the CDC/NIH recommendations state that:
[[Page 54250]]
Occasions will arise when the laboratory director should select
a biosafety level higher than that recommended. For example, a
higher biosafety level may be indicated by the unique nature of the
proposed activity (e.g., the need for special containment for
experimentally generated aerosols for inhalation studies) or by the
proximity of the laboratory to areas of special concern (e.g., a
diagnostic laboratory located near patient care areas). Similarly, a
recommended biosafety level may be adapted to compensate for the
absence of certain recommended safeguards. For example, in those
situations where Biosafety Level 3 is recommended, acceptable safety
may be achieved for routine or repetitive operations (e.g.,
diagnostic procedures involving the propagation of an agent for
identification, typing and susceptibility testing) in laboratories
where facilities satisfy Biosafety Level 2 recommendations, provided
the recommended Standard Biological Practices, Special Practices,
and Safety Equipment for Biosafety Level 3 are rigorously followed.
(Ex. 7-72, pg. 70)
OSHA agrees that it is appropriate that such decisions be made by
the laboratory director and would allow such adaptations to the CDC/NIH
recommendations. However, regardless of adaptations, OSHA requires the
laboratory director to determine and document the need for controlled
access, anterooms, sealed windows, directional airflow, preventing
recirculation of laboratory exhaust air, filtration of exhaust air
before discharge outside, and thimble exhaust connections for
biological safety cabinets. These determinations, along with any
adaptations to the CDC/NIH biosafety level, must be made a part of the
exposure control plan. The documentation will provide information to
the laboratory employees of adaptations to and changes in recommended
biosafety levels.
For employers who provide home health care or home-based hospice
care, paragraph (c)(2)(v) specifies the elements that are to be
included in the exposure control plan. In home health care and home-
based hospice care situations, individuals are in their private homes
receiving health care and other services and thus the employer has
limited control over the work site in which he or she provides those
services. In addition, employers providing such home-based care will
not be transferring individuals identified as having suspected or
confirmed infectious TB from their homes to facilities with isolation
capabilities, nor will the employer be initiating isolation precautions
in the home. In recognition of the uniqueness of home-based work
settings, OSHA has limited the elements of the exposure control plan
for an employer who provides home health care and home-based hospice
care. The elements included under this paragraph are intended to
address the type of activities that are likely to occur in the home
health care work setting. Under this paragraph the employer must
include procedures for prompt identification of individuals with
suspected or confirmed infectious TB and for minimizing employee
exposure to such individuals. As discussed above, in order for
employees to take proper precautions in protecting themselves from
exposure to TB, it is essential that there be procedures to identity
potentially infectious individuals. In many cases the home health care
employer may already know that the individual has been identified as
having suspected or confirmed infectious TB and has been confined to
their home. However, in other cases, an individual may be suffering
from other immunocompromised conditions and may develop active TB.
Because employees in home health care and home-based hospice care may
be providing services to individuals at risk of developing active TB,
it is necessary that there be procedures in place for identifying those
individuals. In addition, the exposure control plan must include
procedures for minimizing employee exposure. Such procedures might
include minimizing the time spent in the home by combining tasks to
limit the number of entries or by minimizing the number of employees
who must enter the home along with the time they spend there. Paragraph
(c)(2)(v) also requires that the exposure control plan include a list
of high-hazard procedures, if any, performed in the workplace and
procedures for delaying elective high-hazard procedures until the
individual is noninfectious. Listing the high-hazard procedures will
serve to identify those procedures that may require special
considerations. In the home setting, this would not include the use of
AFB isolation precautions. To the extent possible the employer should
also include procedures for when these types of procedures can be
delayed. This will decrease the exposure of employees to aerosolized M.
tuberculosis that might be generated performing these procedures.
Paragraph (c)(2)(vi) stipulates that the employer must document the
number of confirmed infectious tuberculosis cases encountered in the
work setting in the past 12 months in the Exposure Control Plan
whenever the employer is using this information to claim reduced
responsibilities related to paragraph (b), Application, and paragraph
(g)(3)(iii)(D), Medical Surveillance, of the standard. Under paragraph
(b), employers are relieved from implementing certain provisions of the
standard if they do not admit or provide medical services to
individuals with suspected or confirmed infectious TB and they can
demonstrate that, in the past 2 years, there have been no cases of
confirmed infectious TB reported in the local county in one or both
years and, if any cases have occurred in one of the past 2 years, fewer
than 6 confirmed infectious cases were reported in that year.
Furthermore, employers desiring to follow the limited program must
demonstrate that no such cases have been encountered in his or her
employees' work setting in the past 12 months. Under paragraph
(g)(3)(iii)(D) of Medical Surveillance, employees with negative TB skin
tests are to be provided with a TB skin test every 6 months if the
employee works in an intake area where early identification procedures
are performed in facilities where six or more individuals with
confirmed infectious TB have been encountered in the past 12 months.
However, if the employer can document that fewer than 6 individuals
with confirmed infectious TB have been encountered in the facility, the
employee in the intake area would only have to be provided with a TB
skin test annually. The count of the number of confirmed infectious TB
cases in the exposure control plan would serve to document that fewer
than 6 individuals with confirmed infectious TB had been encountered in
the past 12 months, thus relieving the employer of the burden of
providing skin tests every 6 months for those affected employees.
Paragraph (c)(2)(vii)(A) requires that a copy of the exposure
control plan be accessible to employees. The reason for this is to
assure that an employee can get and consult the exposure control plan
within a reasonable time, place and manner. Having access to the plan
encourages employees to develop a complete understanding of the plan
and its application, so that the program can be carried out by both
employer and employees. Having the plan available also serves as an on-
site adjunct to the overall infection control program and may reinforce
the training programs.
For fixed work sites and primary workplace facilities, the plan
must be maintained on-site at all times. For those situations where an
employee(s) travels between work sites or where the employee's work is
carried out at more than one geographical location, the plan may be
maintained at the primary workplace facility. To ensure access, the
plan should be in a central location
[[Page 54251]]
where an employee may see it whenever he or she wishes. However, in
order to allow flexibility, OSHA is not specifying where the plan must
be kept. The employer is permitted to determine where the plan is kept
provided that the employee can access a copy of the plan at the
workplace, within the workshift. For example, if the plan is maintained
on a computer, access to the computer or hard copy must be available to
the employee. Likewise, if the plan is comprised of several separate
policy documents, copies of all documents must be accessible in
addition to any general policy statement or guiding document that may
exist.
Paragraph (c)(2)(vii)(B) requires that the exposure control plan be
reviewed at least annually and updated whenever necessary to reflect
new or modified tasks, procedures, or engineering controls that affect
occupational exposure and to include new or revised employee positions
with occupational exposure. An example of such a situation would be
when an employer in a facility that had previously transferred
individuals with suspected or confirmed infectious TB decided that such
individuals would be admitted and provided medical services. The
purpose of this requirement is to assure that all new tasks and
procedures are evaluated in order to determine whether they could
result in occupational exposure. New and revised job classifications
must be added to the lists of job classifications and tasks and
procedures identified in (c)(1)(i) of this section in order to assure
full coverage of occupationally exposed employees. The updating must
occur as soon as feasible and may not be postponed until the annual
review.
Paragraph (c)(2)(vii)(C) requires that the exposure control plan be
made available to the Assistant Secretary and the Director upon request
for examination and copying. The purpose of this requirement is to
allow the OSHA representative to review an employer's plan, including
the exposure determination of employees at risk for occupational
exposure. Although the Assistant Secretary or the Director could
request the plan at any time, it will usually be requested by an OSHA
compliance safety and health officer (CSHO) during the course of a
workplace inspection. The CSHO needs to examine the plan in order to
see what procedures and program planning for the control of
occupational exposures have been instituted and whether they meet the
requirements of the standard.
Paragraph (d) Work Practices and Engineering Controls
It is generally acknowledged that protection of the employee is
most effectively attained by elimination or minimization of the hazard
at its source, which engineering controls and work practices are both
designed to do. Industrial hygiene principles also teach that control
methods that depend upon the vagaries of human behavior are inherently
less reliable than well-maintained mechanical methods. For these
reasons, OSHA has preferred engineering and work practice controls and
has required, under paragraph (d)(1), that they be used to eliminate or
minimize employee exposure to M. tuberculosis. Nevertheless, OSHA
recognizes that situations may exist in which neither of these control
methods is feasible and that, in these circumstances, employee
protection must be achieved through the use of personal protective
equipment, primarily respirators. In other situations, personal
protective equipment may have to be utilized in conjunction with
engineering controls and/or work practices to obtain a further
reduction in employee exposure.
Engineering controls serve to reduce employee exposure in the
workplace by either removing the hazard or isolating the worker from
exposure. These controls include process or equipment redesign, process
or equipment enclosure (e.g., biosafety cabinets), and employee
isolation. In general, engineering controls act on the source of the
hazard and eliminate or reduce employee exposure without reliance on
the employee to take self-protective action.
In comparison, work practice controls reduce the likelihood of
exposure through alteration of the manner in which a task is performed
(e.g., closing the door of an AFB isolation room immediately upon
entering or exiting). Although work practice controls also act on the
source of the hazard, the protection they provide is based upon
employer and employee behavior rather than installation of a physical
device. In many instances these two control methodologies work in
tandem, because it is often necessary to employ work practice controls
to assure effective operation of engineering controls. Under the
provisions of the preceding paragraph, Exposure Control Plan, the
employer is required to develop a number of work practices relative to
controlling occupational exposure to TB. In paragraph (d)(2), these
work practices are required to be implemented in the work setting.
In developing the methods of compliance section for this proposal,
OSHA carefully considered the work environments that have the potential
for producing occupational exposures. Since the source of the hazard is
frequently a living person, typical methods of reducing or eliminating
the hazard at the source may not always be feasible. For example, in an
industrial operation a process may be entirely enclosed and operated or
monitored by an employee at a remote location, a situation that would
rarely, if ever, occur in the work settings covered by this standard.
The Agency believes, therefore, that prevention of exposures to M.
tuberculosis will often require use of a combination of control methods
to achieve adequate protection of employees. Paragraph (d)(1) requires
work practices and engineering controls to be used to eliminate or
minimize employee exposures.
Not all facilities will have the capabilities to admit or provide
medical services to individuals with suspected or confirmed infectious
tuberculosis. Consequently, these facilities will have to transfer such
individuals to another facility where isolation rooms or areas are
available. Paragraph (d)(3) requires that individuals with suspected or
confirmed infectious TB must be identified and, except in settings
where home health care or home-based hospice care is provided, shall
be: (i) masked or segregated in such a manner that contact with
employees who are not wearing respiratory protection is eliminated or
minimized until transfer or placement in an AFB isolation room or area
can be accomplished; and (ii) placed in an AFB isolation room or area
or transferred to a facility with AFB isolation rooms or areas within 5
hours from the time of identification, or temporarily placed in AFB
isolation within 5 hours until placement or transfer can be
accomplished.
Masking or segregation of individuals with suspected or confirmed
infectious TB while those individuals are awaiting placement in
isolation or transfer to another facility is done to assure that
employee exposure is minimized to the extent feasible. This provision,
drawn from CDC recommendations (Ex. 4B), is aimed at minimizing the
exposure of employees in areas where individuals are first identified
as having suspected or confirmed infectious TB. Although CDC recommends
masking such individuals, OSHA presents a choice of masking or
segregation because the Agency believes that this practice is directly
involved with the medical management of such individuals. It is OSHA's
mission to protect employees
[[Page 54252]]
from occupational exposure to tuberculosis and it is not the Agency's
intent to dictate medical practice relative to individuals with
suspected or confirmed infectious TB. Therefore, where the employer has
chosen not to mask individuals with suspected or confirmed infectious
TB when they are not in isolation rooms or areas or when such
individuals cannot be masked (e.g., because they are combative), the
employer must segregate these individuals in a manner such that contact
with employees who are not wearing respiratory protection is eliminated
or minimized. Segregation could be accomplished, for example, by having
the individual wait in an area out of the main traffic of a waiting
room or intake area or in a vacant examination room that is not needed
for patient/client consultations. The time that a facility can permit
an individual to await placement or transfer is limited to 5 hours.
After that the individual must be placed in isolation.
The primary purposes of AFB isolation rooms or areas are to (1)
isolate patients who are likely to have infectious TB from unprotected
employees, (2) prevent escape of droplet nuclei from the room, thus
preventing entry of M. tuberculosis into the corridor and other areas
of the facility where unprotected employees may be exposed, and (3)
provide an environment that will promote reduction of the concentration
of droplet nuclei through various engineering controls (Ex. 4B). All of
these will reduce employee exposure. Indeed, placement of individuals
with suspected or confirmed infectious TB in an AFB isolation room is
the most effective way to prevent or lessen transmission.
OSHA has proposed that individuals with suspected or confirmed
infectious TB be isolated or transferred within 5 hours from the time
of being identified as a suspected or confirmed case. The Agency
realizes that the time it will take to isolate or transfer an
individual once he or she is identified as having suspected or
confirmed infectious TB may vary and that circumstances may arise that
cause delays in initiating isolation (e.g., all isolation rooms may be
occupied by other patients). However, OSHA is also concerned about the
amount of time an individual, who has been identified as having
suspected or confirmed infectious TB, should be permitted to stay in
non-isolation areas. Individuals who must wait for extended periods of
time before placement in AFB isolation or transfer may present a risk
of exposure to employees working in these areas even though these
individuals may be masked. A study by Moran et. al. shows that
emergency departments that made a presumptive diagnosis of TB were able
to initiate isolation in an average of 5 hours from the time of patient
registration (Ex. 7-251). Patient registration usually precedes
identification. The standard requires that procedures be in place for
prompt identification of individuals with suspected or confirmed
infectious TB. In view of this requirement and the fact that the study
was based on time elapsed from patient registration to isolation, which
included the time the patient waited to be medically observed, the
Agency has preliminarily concluded that five hours from the time of
being identified is a reasonable cutoff point for transfer or placement
in isolation.
The Agency's concern regarding permitting identified individuals to
wait for extended periods, even though they are masked, before they are
transferred or isolated is not unfounded. The American Thoracic
Society, in its document Control Of Tuberculosis In The United States,
states:
* * *Patients unable to cooperate in covering coughs and sneezes
can wear ordinary surgical masks for short periods, for example,
while being transported within institutions. For longer periods,
masks on patients are stigmatizing, uncomfortable, and probably
ineffective. (Ex. 5-80) (emphasis added)
Consequently, a cutoff point of 5 hours has been proposed as the
maximum amount of time individuals who have been identified with
suspected or confirmed infectious TB may await transfer or placement
into AFB isolation. As discussed under the Exposure Control Plan,
paragraph (c), employers are required to have procedures in place for
isolating or transferring individuals identified with suspected or
confirmed infectious TB so that AFB isolation can be executed
expeditiously. Five hours would appear to be a reasonable amount of
time to carry out these procedures. OSHA believes that longer periods
of time are likely to pose too great a risk of exposure to employees in
the vicinity. The longer an individual with suspected or confirmed
infectious TB remains outside of AFB isolation, the greater the risk of
transmission.
It should be noted that the 5-hour cutoff is the amount of time
allotted per facility to accomplish AFB isolation or transfer of these
individuals. More specifically, if an individual spent 4 hours awaiting
transfer at an identifying facility, the receiving facility would still
be allowed 5 hours to accomplish isolation, not just the one hour
remaining since initial identification of the individual. The intent of
the proposed facility-based 5-hour period is to allow the receiving
facility adequate time to accomplish isolation and to recognize that
the receiving facility should not be held responsible for circumstances
beyond the facility's control (e.g., the time the individual waited
before arrival at the receiving facility).
If placement or transfer cannot be completed within five hours, it
must be done as soon as possible thereafter. In addition, the employer
must assure in such a case that his or her facility has AFB isolation
rooms or areas for the isolation of the individual until placement or
transfer can be accomplished. More specifically, it is not necessary to
construct a dedicated AFB isolation room or area to isolate such
individuals while awaiting transfer or placement within the facility.
The definition of ``AFB isolation room or area'' states that this may
be a room, area, booth, tent, or other enclosure that is maintained at
negative pressure to adjacent areas in order to control the spread of
aerosolized M. tuberculosis. For example, such isolation might be
achieved by placing a portable stand-alone HEPA filtration unit (vented
to the outside) in an unused examination room. Another method is the
use of a rigid enclosure on casters with a ventilation unit to achieve
negative pressure, a window kit to safely exhaust the enclosure's air
to the outside, and a digital pressure monitor to assure maintenance of
negative pressure within the enclosure. As is the case with any AFB
isolation room or area, the means used to isolate an individual
awaiting placement or transfer must achieve negative pressure and have
its air safely discharged to the outside. OSHA seeks comment regarding
the 5-hour limit on placement or transfer and measures that can be used
for AFB isolation in those situations when transfer or placement cannot
be accomplished within that time.
Paragraph (d)(4) stipulates that high-hazard procedures must be
conducted in AFB isolation rooms or areas. High-hazard procedures as
defined in paragraph (b), Definitions, are procedures performed on an
individual with suspected or confirmed infectious TB in which the
probability of M. tuberculosis being expelled into the air is
increased. These procedures include, but are not limited to,
endotracheal intubation and suctioning, diagnostic sputum induction,
aerosol treatments (including pentamidine therapy), pulmonary function
testing, and bronchoscopy. These procedures also include autopsy,
clinical, surgical, and laboratory procedures that may
[[Page 54253]]
aerosolize M. tuberculosis. In view of the increased probability of
droplet nuclei generation associated with these procedures, all high-
hazard procedures are required to be performed in rooms, areas, or
booths that meet AFB isolation criteria (e.g., negative pressure) in
order to contain the droplet nuclei and eliminate or minimize employee
exposure. Other procedures that may generate aerosols (e.g., irrigation
of tuberculous abscesses, homogenizing or lyophilizing infectious
tissue), are also covered by this provision. (See paragraph (e) of this
proposal for requirements for microbiological practices and containment
equipment in laboratories.)
Paragraph (d)(5) requires that engineering controls be used in
facilities that admit or provide medical services or AFB isolation to
individuals with suspected or confirmed infectious TB except in
settings where home health care or home-based hospice care is being
provided. For example, engineering controls must be used in isolation
rooms or areas, areas where high hazard procedures are performed, and
autopsy rooms where M. tuberculosis may be aerosolized. This provision
specifically excepts settings where home health care or home-based
hospice care is being provided. In such situations, the employer is not
in control of the employee's work setting because the setting is the
private home of the individual being provided with care. In view of
this, an employer providing home health care or home-based hospice care
would not be required to implement engineering controls in the
individual's home.
In conjunction with this provision, paragraph (d)(5)(i) requires
that negative pressure be maintained in AFB isolation rooms or areas.
The purpose of this provision is to prevent the escape of aerosolized
M. tuberculosis from a room and into the corridors and other areas of
the facility where unprotected employees may be exposed. In order for
air to flow from one area to another, there must be a difference in the
pressure between the two areas. Air will flow from the higher pressure
to the lower pressure area. The lower pressure area is at ``negative
pressure'' relative to the higher pressure area. The level of negative
pressure achieved will depend on the physical configuration of the
area, including the air flow path and flow openings. A pressure
differential of 0.001 inch of water and an inward air velocity of 100
feet per minute (fpm) are minimum acceptable levels. The pressure
difference necessary to achieve and maintain negative pressure in a
room is very small and may be difficult to measure accurately. Negative
pressure can be achieved by balancing the room supply and exhaust flows
to set the exhaust flow to a value of 10% [but no less than 50 cubic
feet per minute (cfm)] greater than the supply (Ex. 4B).
As stated above, the negative pressure principle plays an important
role in controlling the spread of M. tuberculosis to other areas of the
facility where unprotected workers may be exposed. In isolation rooms
and areas, and in areas where high hazard procedures (including
autopsies) are performed, engineering controls creating negative
pressure will prevent the escape of droplet nuclei from the room, thus
preventing dispersion of M. tuberculosis into the corridor and other
areas of the facility where unprotected employees may be working.
In addition, negative pressure fulfills the secondary purpose of
general ventilation by reducing the concentration of contaminants in
the air. General ventilation maintains air quality by two processes,
dilution and removal of airborne contaminants. Dilution reduces the
concentration of contaminants in a room by supplying air that does not
contain those contaminants. The supply air mixes with and then
displaces some of the contaminated room air, which is subsequently
removed from the room by the exhaust system. This process reduces the
concentration of droplet nuclei in the room air and the risk of TB
transmission.
OSHA is not proposing to allow the use of ultraviolet germicidal
irradiation (UVGI) in place of ventilation for controlling aerosolized
M. tuberculosis. Although the germicidal properties of certain
wavelengths of ultraviolet light (UV-C) are generally recognized, the
Agency has not included UVGI as a primary engineering control in the
proposed standard. With regard to the use of UVGI, CDC states:
Because the clinical effectiveness of UV systems varies, and
because of the risk for transmission of M. tuberculosis if a system
malfunctions or is maintained improperly, UVGI is not recommended
for the following specific applications: 1. Duct systems using UVGI
are not recommended as a substitute for HEPA filters if air from
isolation rooms must be recirculated to other areas of a facility.
2. UVGI alone is not recommended as a substitute for HEPA filtration
or local exhaust of air to the outside from booths, tents, or hoods
used for cough-inducing procedures. 3. UVGI is not a substitute for
negative pressure. (Ex. 4B)
The CDC goes on to discuss a number of factors that affect the
effectiveness of UVGI and UV lamps in killing airborne tubercle
bacilli. These factors include the intensity of UVGI, the duration of
irradiation of the organism, the relative humidity of the environment,
the age of the UV lamp, and the amount of dust on the lamp's surface
(Ex. 4B). In light of this information, the Agency does not believe
that UVGI can reliably and uniformly control airborne tubercle bacilli.
Consequently, UVGI is not acceptable as a primary engineering control.
However, some employers may choose to use UVGI as a supplement to
ventilation or HEPA filtration. In recognition of this, OSHA has
included information regarding UVGI safety and health concerns in
Appendix D of this section.
Paragraph (d)(5)(ii) requires that in those areas where negative
pressure is required (i.e., AFB isolation rooms or areas), maintenance
of negative pressure must be qualitatively demonstrated (e.g., by smoke
trails) daily while in use for tuberculosis isolation. In Supplement 3
of its 1994 guidelines, CDC states:
TB isolation rooms should be checked daily for negative pressure
while being used for TB isolation. (Ex. 4B)
The principle and advantages of negative pressure have been discussed
above. Proper maintenance of negative pressure will prevent the
contaminated air from escaping from the room or area and exposing
unprotected employees. One means of qualitatively demonstrating
negative pressure is through the use of smoke trail testing (see
Appendix G of this section). Other methods include flutter strips or
continuous monitoring devices. With regard to the safety and
effectiveness of these methods, the CDC states:
The concern over the use of smoke tubes is unfounded. Controlled
tests by NIOSH have shown that the quantity of smoke that is
released is so minute that it is not measurable in the air. The
location of the patient and the length of time the patient is
exposed dilute the smoke to several orders of magnitude below an 8-
hour exposure limit. It is not practical and often not effective to
use flutter strips or continuous monitoring devices as alternatives
to indicate directional air movement. The air flow (due usually to
the small clearance area under the door) is insufficient to move the
flutter strip. Likewise, low negative pressure, which will
satisfactorily provide adequate directional air flow into the
isolation room, may not be readable on continuous monitoring
devices. Devices must be capable of reading 0.001 inch of water, the
established minimum, to be effective. (Ex. 4B)
In light of this information, employers should be aware that when
choosing a method other than smoke trails to demonstrate maintenance of
negative pressure, the method chosen should be
[[Page 54254]]
reviewed carefully in order to assure that the intended test can be
effectively conducted.
Paragraph (d)(5)(iii) stipulates that engineering controls must be
maintained, and inspected and performance monitored for filter loading
and leakage every six months, whenever filters are changed, and more
often if necessary to maintain effectiveness. The primary intent of
this provision is to assure that engineering controls are maintained in
such a manner that they continue to function effectively. As discussed
previously, a number of factors can affect the functioning of
engineering controls, such as frozen bearings, broken belts, and burned
out motors. It is the employer's responsibility to maintain engineering
controls in proper working condition. That is, if a belt breaks on a
fan motor, it is not appropriate to delay repairs until the six-month
inspection. This provision does, however, stipulate a maximum time
period of six months between inspections and performance monitoring of
engineering controls and HEPA filters in air systems carrying air that
may reasonably be anticipated to contain aerosolized M. tuberculosis.
The employer's maintenance schedule may specify more frequent
inspection, maintenance, and performance monitoring based upon
conditions found in that particular work site. For example, the
employer, being more familiar with his or her own work setting, may
have knowledge that the work environment is very dusty, thus
necessitating a more frequent period for changing the filters. When
filters are changed, performance monitoring must be conducted to assure
that the filter has been correctly installed and is functioning
properly. In view of the importance of these systems in reducing the
concentration of droplet nuclei and thereby the risk of TB
transmission, OSHA believes that six months is the longest period that
these systems should be allowed to operate without inspection and
performance monitoring. This maximum six-month period of time between
consecutive inspections and performance monitoring of HEPA filters is
supported by CDC (Ex. 4B).
Paragraph (d)(5)(iv) requires that air from AFB isolation rooms or
areas must be exhausted directly outside, away from intake vents and
employees. If the air from these areas cannot be exhausted in such a
manner or must be recirculated, it must pass through HEPA filters
before discharge or recirculation.
In order for the air to be safely discharged, exhaust ducts must
not be located near areas that may be populated (e.g., sidewalks or
windows that may be opened). In addition, ventilation system exhaust
discharges must be designed to prevent re-entry of exhaust air. Wind
blowing over a building creates a highly turbulent recirculation zone,
which can cause re-entry of the exhaust into the building. Exhaust flow
needs to be discharged above the zone. When exhaust air cannot be
safely discharged, it must pass through HEPA filters to remove droplet
nuclei, thereby precluding re-entry of potentially contaminated air or
exposure of individuals who may have to pass through the exhaust
airstream. The employer should be aware that exhausting of this air may
also fall under federal, state and local regulations concerning
environmental discharges.
This provision also states that if a portion of this air is
recirculated, it must pass through a properly designed, installed, and
maintained HEPA filter before discharge back into general facility
ventilation. HEPA filters clean air through the physical removal of
particulates from the airstream. These filters have a minimum removal
efficiency of 99.97% for particles 0.3 microns in diameter.
Droplet nuclei of M. tuberculosis range in size from 1 micron to 5
microns in diameter. Therefore, HEPA filtration can be expected to
remove most droplet nuclei from the air. It should be noted that
whenever feasible, exhaust air from the AFB isolation rooms or areas
must be exhausted to the outside. In its 1994 guidelines, CDC states:
Air from TB isolation rooms and treatment rooms used to treat
patients who have confirmed or suspected infectious TB should be
exhausted to the outside in accordance with applicable Federal,
state, and local regulations. The air should not be recirculated
into the general ventilation. In some instances, recirculation of
air into the general ventilation system from such rooms is
unavoidable (i.e., in existing facilities in which the ventilation
system or facility configuration makes venting the exhaust to the
outside impossible). In such cases, HEPA filters should be installed
on the exhaust duct leading from the room to the general ventilation
system to remove infectious organisms and particulates the size of
droplet nuclei from the air before it is returned to the general
ventilation system (Section II.F; Suppl. 3). Air from TB isolation
rooms and treatment rooms in new or renovated facilities should not
be recirculated into the general ventilation system. (Ex. 4B)
The Agency agrees with CDC that exhaust air should be vented to the
outside. However, OSHA recognizes that there may be instances where
outside discharge may not be feasible and has, therefore, permitted
recirculation with HEPA filtration of the recirculated air, in such
instances.
Paragraph (d)(5)(v) states that ducts carrying air that may
reasonably be anticipated to contain aerosolized M. tuberculosis must
be maintained under negative pressure for their entire length before
in-duct HEPA filtration or until the ducts exit the building for
discharge. Ducts maintained under negative pressure will contain
exhaust air within the system. Air will not escape to the outside as it
would under positive pressure even if there are leaks in the ducts. The
purpose of this provision is to prevent escape of air that may contain
aerosolized M. tuberculosis into areas where occupational exposure is
not anticipated and unprotected employees may be exposed.
Paragraph (d)(5)(vi) requires that, while in use for TB isolation,
doors and windows of AFB isolation rooms or areas must be kept closed
except when doors are opened for the purpose of entering or exiting and
when windows are part of the ventilation system being used to achieve
negative pressure. For example, the window may be serving as the exit
for the exhaust from an in-room HEPA filtration unit. As stated above,
AFB isolation rooms and areas are to be maintained under negative
pressure while in use for TB isolation. Negative pressure in a room can
be altered by small changes in the ventilation system operation, or by
the opening and closing of the isolation room doors or windows. In
order to assure that the ventilation system functions as intended, it
is essential that, once an operating configuration has been
established, doors and windows be opened only when necessary.
Paragraph (d)(5)(vii) stipulates that when an AFB isolation room or
area is vacated by an individual with suspected or confirmed infectious
TB, the room or area must be ventilated for an appropriate period of
time, according to current CDC recommendations for a removal efficiency
of 99.9%, before permitting employees to enter without respiratory
protection (see Appendix C of this section). The time required for
removing airborne particles from an enclosed space depends on several
factors. These include the number of air changes per hour (which is
determined, in part, by the number of cubic feet of air in the room or
booth), the rate at which air is entering the room or booth at the
intake source versus the rate at which it is being exhausted, the
location of the ventilation inlet and outlet, and the physical
configuration of the room or booth. The times needed to achieve a given
removal efficiency (i.e., 90%, 99%, and 99.9%) presented in
[[Page 54255]]
Appendix C of this section assume perfect air mixing within a space.
However, perfect mixing of air normally does not occur because a number
of factors, such as room configuration, may influence the movement of
air. Because perfect air mixing is not likely to occur, the necessary
time required for a specific removal efficiency, as presented in
Appendix C of this section, may be underestimated. In order to
compensate for this shortcoming, OSHA has proposed that the most
conservative (i.e., protective) removal efficiency, i.e., 99.9%, be
used to determine the appropriate amount of time an AFB isolation room
or area must be ventilated before permitting employees to enter without
respiratory protection. Using this conservative approach will help to
assure that an appropriate time has passed before unprotected employees
enter the area, even in situations where perfect air mixing has not
occurred. Ventilation of the room would not be necessary if the room
was previously occupied by an individual with suspected infectious
tuberculosis and that individual was medically determined to be
noninfectious, since there would be no droplet nuclei present.
Paragraph (d)(6) requires that the employer must inform any outside
contractor who provides temporary or contract employees who may incur
occupational exposure of the hazard, so that the contractor can
institute precautions to protect his or her employees. OSHA is
concerned that the contractor be aware of the existence of TB hazards
so that appropriate actions can be undertaken to prevent the
contractor's employees from being unwittingly exposed. By conveying
such information to the contractor, accountability for these employees
is established. If the contractor is aware of the hazards, then it is
the responsibility of the contractor to institute procedures to protect
his or her employees from occupational exposure to M. tuberculosis.
Paragraph (e) Clinical and Research Laboratories
This paragraph addresses requirements that must be met by clinical
and research laboratories engaged in the culture, production,
concentration, experimentation, and manipulation of M. tuberculosis.
These requirements apply in addition to the other requirements of the
standard.
The risks associated with direct and routine work with pathogens
have long been recognized:
Microbiology laboratories are special, often unique, work
environments that may pose special infectious disease risks to
persons in or near them. Personnel have contracted infections in the
laboratory throughout the history of microbiology. (Ex. 7-72)
Clinical and research laboratories working with M. tuberculosis are no
exception, and the risks associated with work in such facilities
warrant additional protective measures.
Prior to 1984, no single code of practice, standards, guidelines or
other publication providing detailed descriptions of techniques or
equipment for laboratory activities involving pathogens was available.
In that year, the CDC and the National Institutes of Health (NIH)
published guidelines entitled ``Biosafety in Microbiological and
Biomedical Laboratories''. These biosafety guidelines were based on
combinations of standard and special practices, equipment, and
facilities recommended for use when working with various infectious
agents in laboratory settings. The most current revision of these
guidelines is dated 1993. (Ex. 7-72)
The biosafety guidelines are not limited to M. tuberculosis, which
is the subject of this standard. They are applicable to work with any
infectious agent. The basic format for the biosafety guidelines
categorizes infectious agents and laboratory activities into four
classes or levels denoted as Biosafety Levels 1 through 4. These
biosafety levels (BSL) are comprised of combinations of laboratory
practices and techniques, safety equipment, and laboratory facilities
appropriate for the operations performed and the hazard posed. The
Guidelines indicate the BSL to be used when working with various
infectious agents and infected animals.
There is a risk to employees working with materials containing M.
tuberculosis. When the concentration of this bacterium is increased as
the result of growing it in cell culture or through artificial
concentration, then the risk of transmission to employees increases if
the bacteria are not contained. Therefore, the proposed standard
requires the employer to implement a number of provisions specifically
related to these laboratory work settings.
The requirements in paragraph (e), including those regarding
biosafety cabinets, are derived primarily from the CDC/NIH
recommendations found in ``Biosafety in Microbiological and Biomedical
Laboratories'' (Ex. 7-72). Only those provisions that relate to the
health and safety of employees are required by the standard. The
provisions in paragraph (e) are a minimal program, and OSHA anticipates
that employers affected by this paragraph will continue to follow any
other appropriate portions of the above recommendations in addition to
the requirements of this standard. In addition, the employer is
responsible for following this entire standard (e.g. training
employees, medical surveillance).
Paragraph (e) applies to two types of facilities that OSHA has
designated as ``clinical laboratories'' and ``research laboratories.''
For the purpose of this standard a clinical laboratory is a laboratory
or area of a facility that conducts routine and repetitive operations
for the diagnosis of TB, such as preparing acid-fast smears and
culturing sputa or other clinical specimens for identification, typing
or susceptibility testing. A research laboratory is a laboratory that
propagates and manipulates cultures of M. tuberculosis in large volumes
or high concentrations that exceed those used for the identification
and typing activities common to clinical laboratories.
The proposed standard requires, in paragraphs (e)(2)(i)(A) through
(D), that both clinical and research laboratories follow several
standard microbiological practices. All procedures are to be performed
in a manner that minimizes the creation of aerosols. In view of the
mode of transmission of M. tuberculosis, that is, through inhalation of
airborne organisms, this provision is extremely important in
eliminating or minimizing employee exposure. It is the responsibility
of the employer to evaluate laboratory tasks and institute the measures
necessary to minimize the creation of aerosols.
OSHA also proposes to adopt the good laboratory and infection
control practice of prohibiting pipetting or suctioning by mouth. The
use of cotton plugs or other barriers does little to reduce the hazards
of mouth pipetting. Even a technician who is skilled in mouth pipetting
may inadvertently suck fluids containing M. tuberculosis into the
mouth. In addition to producing M. tuberculosis-containing aerosols
when the fluid is expelled, these fluids may also contain bloodborne
pathogens that would have contacted the employee's mucous membranes
(i.e., the mouth) as well as any blisters, cuts, or other lesions in
the mouth or on the lips.
Work surfaces and laboratory equipment must be decontaminated at
the end of each shift and after any spill of viable material. This is
recognized as good laboratory practice in minimizing the spread of
contamination.
Finally, the proposed standard requires that all cultures, stocks,
and other wastes contaminated with M. tuberculosis be decontaminated
before
[[Page 54256]]
disposal by a decontamination method, such as autoclaving, known to
effectively destroy M. tuberculosis. Materials to be decontaminated
outside of the immediate laboratory are to be placed in a durable
leakproof container, closed to prevent leakage for transport from the
laboratory, and labeled or color coded in accordance with paragraph
(h)(1)(ii) of this section. Decontamination before disposal helps
assure that other employees are not inadvertently exposed to the
bacterium.
Although the proposed standard requires proper containerization of
laboratory wastes, it includes no such requirement for wastes
originating from the provision of care or services to individuals with
suspected or confirmed infectious TB (e.g., facial tissues that the
individual has used). The reason for this is that items, such as facial
tissues, capture and contain the liquids generated by the individual.
Once captured, the liquid is not readily aerosolized. In their
guidelines, the CDC states:
Disposable items contaminated with respiratory secretions are
not associated with transmission of M. tuberculosis. (Ex. 4B)
In the laboratory, however, the liquids containing M. tuberculosis are
generally not captured or contained on an item but exist as an
individual specimen or culture. Also, in some instances, the bacilli
have been concentrated. The possibility, therefore, for formation of
droplet nuclei from these wastes is increased. Consequently, it is
necessary to properly containerize and label laboratory wastes to
assist in preventing droplet nuclei formation and possible infection.
Proper containerization and labeling of wastes to be decontaminated
outside a laboratory not only help prevent employee exposure but also
warn employees who come in contact with this waste of the hazard within
the container.
Paragraphs (e)(2)(ii)(A) through (E) describe special practices to
be followed in clinical and research laboratories, such as limiting
access to the laboratory to authorized personnel, preparing and
maintaining a biosafety manual, properly containerizing materials
contaminated with M. tuberculosis, immediately containerizing and
cleaning up all spills potentially contaminated with M. tuberculosis,
and posting a sign with the universal biohazard symbol on access doors
when materials containing or animals infected with M. tuberculosis are
present. Limiting access to these laboratories assures that
unauthorized individuals are not placed at risk, and that they do not
distract or otherwise interfere with the activity of the authorized
employees. This provision works in concert with the requirement for
signs in paragraph (h)(2)(iv) and ensures that only employees who meet
the special requirements set forth by the laboratory director, which
will include training, personal protective equipment, and other
requirements, could enter the area.
The requirement for a biosafety manual helps assure that any
additional procedures are developed to address situations that are
unique to a particular facility and to provide appropriate protection
to exposed employees. The manual must be reviewed as necessary and at
least annually. The manual must also be updated as necessary to reflect
changes in the work setting. The phrase ``as necessary'' has been used
to indicate that updating of the manual to reflect work setting changes
is to be done as soon as possible and is not to be postponed until the
annual review. Employees are required to read the biosafety manual's
sections on potential hazards and practices and procedures.
The requirement that contaminated material removed from the work
area be placed in a container that prevents leakage during collection,
handling, processing, storage, transport, or shipping is to assure that
there are no accidental spills or other contamination that may place
other employees at risk.
Paragraph (e)(2)(ii)(D) requires that spills be cleaned up
immediately by employees trained and equipped to work with potentially
concentrated M. tuberculosis. Because M. tuberculosis can become
aerosolized during cleanup procedures, the task cannot be done by
someone who is not skilled and properly equipped. In addition, exposure
incidents must be reported so that the post-exposure management and
follow-up required by paragraph (g) can be initiated and the
circumstances surrounding the exposure incidents can be investigated.
Paragraph (e)(2)(ii)(E) requires that, when materials or animals
infected with M. tuberculosis are present in the laboratory, a hazard
warning sign, in accordance with paragraph (h)(2)(iv) of Communication
of Hazards and Training, incorporating the universal biohazard symbol,
shall be posted on all laboratory and animal room access doors. Because
M. tuberculosis is present in the materials listed above, it is
necessary to warn individuals who may enter this area of the hazards
that are present so that they can take proper precautions to guard
themselves against exposure.
The requirements of paragraph (e)(2)(iii)(A) stipulate that
whenever activities with the potential for generating aerosols of M.
tuberculosis are conducted, and whenever high concentrations or volumes
of M. tuberculosis are used, a certified Class 2 biological safety
cabinet must be used. Such materials may be centrifuged in the open
laboratory, i.e., outside of a biosafety cabinet, if sealed rotor heads
or centrifuge safety cups are used. These requirements protect
employees from exposure during the performance of procedures by
assuring that aerosolized M. tuberculosis will be contained and kept
away from the worker's breathing zone.
Paragraph (e)(2)(iii)(B) requires that biological safety cabinets
shall be certified when they are installed, annually thereafter,
whenever they are moved, and whenever filters are changed. Biological
safety cabinets must be certified to ensure that they will provide the
proper protection. The National Sanitation Foundation (NSF) Standard 49
describes design, construction, and performance criteria for biosafety
cabinets. (Ex. 7-135) Moreover, this NSF standard is subject to
periodic review by the NSF in order to keep the requirements consistent
with new technology. OSHA has incorporated the current NSF Standard 49
performance criteria into the OSHA standard. For example, Standard 49
states:
* * * that each cabinet be tested and performance evaluated on
site, assuring that all physical containment criteria are met at the
time of installation, prior to use, and periodically thereafter.
(Ex. 7-135)
NSF Standard 49 also calls for recertification of cabinets at least
annually, when HEPA filters are changed, and after maintenance repairs
or relocation of a cabinet. Therefore, OSHA believes that the
requirements in the proposed standard are appropriate and that cabinets
that are certified by the manufacturer as Class 2 or 3 will provide
adequate protection to employees.
Paragraph (e)(2)(iv) requires that a method for decontamination of
wastes contaminated with M. tuberculosis (e.g., autoclave, chemical
disinfection, incinerator, or other approved decontamination system
known to effectively destroy M. tuberculosis) must be available within
or as near as feasible to the work area. The availability of such
methods of decontamination is required for inactivating or destroying
M. tuberculosis in or on a variety of media, including culture fluids,
plastic ware, and equipment. These materials must be decontaminated to
prevent potential aerosolization of M.
[[Page 54257]]
tuberculosis and inadvertent exposure of employees outside of the
laboratory.
Research laboratories working with M. tuberculosis are held to
several additional requirements. Paragraph (e)(3)(i)(A) requires that
research facilities keep laboratory doors closed when working with M.
tuberculosis. Paragraph (e)(3)(i)(B) requires that access to the work
area be limited to persons who comply with specified entry and exit
requirements. These provisions are adopted from the CDC/NIH
recommendations for ``Biosafety in Microbiological and Biomedical
Laboratories'' (Ex. 7-72). In addition, paragraph (e)(3)(i)(C) requires
that respiratory protection shall be worn in research laboratories when
aerosols cannot be safely contained (e.g., when aerosols are generated
outside a biological safety cabinet). As stated previously, research
laboratories are working with larger volumes and higher concentrations
of M. tuberculosis than clinical laboratories. As such, the risk to
employees from aerosolized bacilli is increased, necessitating that
these employees be protected whenever lapses in containment occur. An
example of when aerosols would be generated would be when a flask
containing M. tuberculosis is dropped and broken outside of the
biosafety cabinet. Another example would be centrifugation of M.
tuberculosis-containing cultures in an open centrifuge without aerosol-
proof centrifuge safety containers, or utilizing such containers but
then opening them outside of the biosafety cabinet (Ex. 7-134).
Paragraph (e)(3)(ii) requires employers to ensure that employees
manipulating cultures and clinical or environmental materials that may
generate M. tuberculosis-containing aerosols, challenging animals with
M. tuberculosis aerosols, harvesting tissues or fluids from infected
animals, or performing necropsies on infected animals use the
appropriate containment equipment and/or devices when performing these
activities. Such equipment and devices include Class 2 or 3 biosafety
cabinets, or appropriate combinations of personal protective equipment
and physical containment devices (such as respirators, centrifuge
safety cups, sealed centrifuge rotors, and containment caging for
animals). This requirement, like the others in this paragraph, is
intended to ensure that employees are protected during the performance
of these potentially high-hazard procedures.
Research laboratories are also held to additional requirements with
regard to facility construction. Paragraph (e)(3)(iii)(A) requires that
the laboratory be separated from areas that are open to unrestricted
traffic flow within the building. Passage through two sets of self-
closing doors is the requirement for entry into the work area from
access corridors or other contiguous areas. This type of entrance
reduces the likelihood of untrained employees accidentally entering the
work area, since such entry necessitates deliberate action on the part
of the individual.
Paragraph (e)(3)(iii)(B) requires that windows in the laboratory be
closed and sealed. This helps assure containment of any aerosols and
helps maintain proper operation of biosafety cabinets through
minimization of cross drafts.
Paragraph (e)(3)(iii)(C) requires that a ducted exhaust air
ventilation system shall be provided which creates directional airflow
that draws air from clean areas into the laboratory toward contaminated
areas. The proper direction of the airflow shall be verified (i.e.,
into the work area) by the employer at least every six months. The
exhaust air shall not be recirculated to any other area of the
building, shall be discharged to the outside, and shall be dispersed
away from occupied areas and air intakes. The requirement that research
laboratories have verified directional airflow into the work area is to
assure that air is drawn into the laboratory toward contaminated areas
to assist in maintaining containment of aerosols within the laboratory.
Paragraph (e)(3)(iii)(D) requires that the HEPA-filtered exhaust
from Class 2 or 3 biosafety cabinets is to be discharged to the outside
of the building or through the building exhaust system. If it is
discharged through the building exhaust system, it must be connected to
this system in a manner that avoids any interference with the air
balance of the cabinets or the building exhaust system. This is
required to assure that biosafety cabinets and the building exhaust
system continue to function as intended.
Paragraph (e)(3)(iii)(E) requires that continuous flow centrifuges
or other equipment that may produce aerosols must be contained in
devices that exhaust air through a HEPA filter before discharge into
the laboratory. This assures that any aerosols which may contain M.
tuberculosis are effectively filtered from the exhaust air before
discharge into the laboratory, thereby protecting employees against
inadvertent exposure.
All of the requirements discussed above were derived directly from
the CDC/NIH's ``Biosafety in Microbiological and Biomedical
Laboratories.'' OSHA requests comment on the applicability and OSHA's
application of CDC/NIH's guidelines for their use in laboratories which
handle M. tuberculosis.
Paragraph (f) Respiratory Protection
Respirators serve as supplemental protection to reduce employee
exposures when engineering and work practice controls are not
sufficient to provide adequate protection against airborne
contaminants.
At the opening of the public hearings for the revision of OSHA's
General Industry Respiratory Standard, 29 CFR 1910.134, the Agency
stated that all aspects of respirator use for protection against
tuberculosis would be addressed in the rulemaking for Occupational
Exposure to Tuberculosis. Consequently, the respiratory protection
portion of this proposal contains all of the respiratory protection
provisions that have been preliminarily determined to be applicable to
respirator use for TB. In the past, OSHA standards have referred to the
Respirator Standard (29 CFR 1910.134) for the general requirements for
respirator use (e.g., written respiratory protection program;
respirator maintenance) and have included only the respirator
provisions specific to the hazard addressed by the standard. OSHA's
approach in this proposal, however, is to include provisions relative
to all aspects of respirator use for tuberculosis. This will provide
interested parties with the opportunity to review and comment on these
aspects. To assure consistency across OSHA respiratory protection
standards, however, OSHA is considering including in the final TB rule
cross-referencing to the general requirements of the Respiratory
Protection Standard (29 CFR 1910.134) and retaining in the final TB
rule only those provisions specific to respirator use for TB. OSHA
seeks comment on this intended approach in the final standard for TB.
Paragraph (f)(1)(i) states that each employer must provide a
respirator to each employee who: (A) enters an AFB isolation room or
area in use for TB isolation; (B) is present during performance of
procedures or services for an individual with suspected or confirmed
infectious TB who is not masked; (C) transports an individual with
suspected or confirmed infectious TB in an enclosed vehicle or who
transports an individual with suspected or confirmed infectious TB
within the facility whenever that individual is not masked; (D)
repairs, replaces, or maintains air systems or equipment that may
reasonably be anticipated to contain aerosolized M. tuberculosis; (E)
[[Page 54258]]
is working in an area where an unmasked individual with suspected or
confirmed infectious TB has been segregated or otherwise confined
(e.g., while awaiting transfer), and (F) is working in a residence
where an individual with suspected or confirmed infectious TB is known
to be present. In addition, paragraph (f)(1)(ii) requires that each
employer who operates a research laboratory provide a respirator to
each employee who is present when aerosols of M. tuberculosis cannot be
safely contained.
In discussing the use of respiratory protection in their
guidelines, CDC states:
Personal respiratory protection should be used by (a) persons
entering rooms where patients with known or suspected infectious TB
are being isolated, (b) persons present during cough-inducing or
aerosol-generating procedures performed on such patients, and (c)
persons in other settings where administrative and engineering
controls are not likely to protect them from inhaling infectious
airborne droplet nuclei. These other settings include transporting
patients who may have infectious TB in emergency transport vehicles
and providing urgent surgical or dental care to patients who may
have infectious TB before a determination has been made that the
patient is noninfectious. (Ex. 4B)
The guidelines also state that respiratory protection should be worn by
personnel who are performing maintenance and testing procedures on HEPA
filtration systems (Ex. 4B). Furthermore, the CDC/NIH document
``Biosafety in Microbiological and Biomedical Laboratories'' recommends
that respiratory protection be worn whenever aerosols of organisms such
as M. tuberculosis cannot be safely contained (Ex. 7-72). Consequently,
employees who may need to wear respirators could include not only
health care providers but also employees such as housekeepers, dietary
personnel, laboratory technicians, employees in intake areas,
maintenance personnel, social workers, and so forth. It is the
employer's responsibility to determine which occupationally exposed
employees would be covered under this provision and, therefore, would
need to wear a respirator.
With regard to utilization of respiratory protection when entering
an AFB isolation room or area, the reader is referred to the definition
of ``AFB isolation room or area'' in paragraph (j), Definitions. This
definition clarifies that the requirement refers not only to situations
such as entering a patient room occupied by an individual with
suspected or confirmed infectious TB but also refers to entering any
area where high-hazard procedures are being performed and entering an
autopsy room where M. tuberculosis may be aerosolized.
Paragraph (f)(1)(i)(B) requires respirator use when an employee is
present during performance of procedures or services for an unmasked
individual with suspected or confirmed infectious TB. This provision is
intended to cover those situations in which a procedure or service is
performed outside of an AFB isolation room or area. For example, a
facility may not have a portable X-ray and may, therefore, perform this
procedure in a standard X-ray room. If the individual is not masked in
such a situation, all employees present (i.e., the X-ray technician and
any other employees in the room) must utilize respiratory protection.
As stated previously under discussion of Scope, employees rendering
emergency medical services may spend time in very close proximity to
individuals with suspected or confirmed infectious TB within an
enclosed vehicle. Even though the individual may be masked, droplet
nuclei that escape capture in the mask are contained within the
vehicle, thereby increasing the likelihood that employees will breathe
droplet nuclei generated when the patient coughs or speaks. In
addition, under paragraph (f)(1)(i)(D), employees who repair, replace,
on maintain air systems or equipment that may reasonably be anticipated
to contain aerosolized M. tuberculosis are at risk of occupational
exposure as a result of exposure to air that could contain aerosolized
bacilli. Therefore, respirator use would be required in this situation.
As discussed under Scope, aerosolized M. tuberculosis is a
recognized hazard to laboratory personnel. When aerosols of M.
tuberculosis cannot be safely contained, such as during a spill, the
employer is required to provide a respirator to each employee who is
present during this time. This is consistent with CDC/NIH
recommendations regarding respirator use in research laboratories (Ex.
7-72).
Unlike some other airborne contaminants, the quantity of M.
tuberculosis that, when inhaled, will result in infection (i.e.,
infectious dose) has not been determined conclusively. The number of
droplet nuclei expelled into a room by an infectious individual or
aerosol-producing procedure and the concentration of droplet nuclei in
a room or area are unknown. Consequently, there is no basis to judge
the effectiveness of other control measures present even though they
may be operating as intended. OSHA therefore agrees with the CDC that,
in the above situations, other controls that may be in place cannot be
assumed to adequately protect employees against exposure to airborne TB
droplet nuclei and therefore that the use of respiratory protection is
necessary.
While OSHA agrees with and has adopted most of the CDC's
recommendations regarding when respiratory protection is necessary, the
Agency has extended respirator use to two additional situations. More
specifically, when an individual with suspected or confirmed infectious
TB is not masked and is transported within a facility, the employee
transporting the individual must wear a respirator. While CDC
recommends masking individuals with suspected or confirmed infectious
TB prior to transporting them, there may be special circumstances in
which the individual may not be masked (e.g., individual is combative
and will not wear a mask). The employee transporting the individual
would most likely spend an extended period of time in close proximity
to the individual, either walking beside or behind (e.g., pushing a
wheelchair) the individual. The employee would, therefore, be walking
directly through the airspace into which the individual would be
expelling droplet nuclei, receiving exposure each time the individual
coughed, resulting in multiple relatively concentrated exposures. In
view of this, the latter portion of paragraph (f)(1)(i)(C) addresses
the Agency's belief that it is necessary and justified that respiratory
protection be worn by the employee to protect against occupational
exposure if the individual is not masked.
The second situation, under paragraph (f)(1)(i)(E), requires
respirator use by an employee when working in an area where an unmasked
individual with suspected or confirmed infectious TB has been
segregated or otherwise confined, for example while awaiting transfer.
As discussed above, it is assumed that such individuals would normally
be masked. Here again, however, there may be circumstances that
preclude the individual from being masked (e.g., the individual is
combative). Therefore, employees who must work in the area where these
unmasked individuals are located, whether working directly with the
individual or performing other duties, must wear a respirator to
protect against possible tuberculosis infection.
Paragraph (f)(1)(i)(F) requires that a respirator be worn by an
employee who is working in a residence where an individual with
suspected or confirmed
[[Page 54259]]
infectious TB is known to be present. In this situation, whether the
individual is masked or unmasked does not trigger respirator use since
the individual has been releasing droplet nuclei into the residence
airspace. The CDC refers to this type of situation in its discussion of
the provision of home health care and states:
Health care workers who provide medical services in the homes of
patients who have suspected or confirmed infectious TB should
instruct such patients to cover their mouths and noses with a tissue
when coughing or sneezing. Until such patients are no longer
infectious, HCWs should wear respiratory protection when entering
these patients' homes. (Ex. 4B)
In addition to home health care and home-based hospice care
workers, other employees, such as social workers who are entering these
residences, would come under this provision. It is the Agency's intent
that a respirator be used by an employee in these situations for the
time that the employee is in the residence and that respirator use
continue until the individual is noninfectious.
The proposed standard, in paragraphs (f)(1)(iii) and (f)(1)(iv),
places several general responsibilities upon the employer regarding
respiratory protection. Paragraph (f)(1)(iii) states that where
respirators are required by the standard, the employer shall provide
them at no cost to the employee and assure that they are used in
accordance with the requirements of the standard. Paragraph (f)(1)(iv)
stipulates further that the employer must assure that the employee dons
a respirator before entering the work settings or performing the tasks
set forth in paragraphs (f)(1)i and (f)(1)(ii) above and uses it until
leaving the work setting or completing the task, regardless of other
control measures in place.
It has been OSHA's long-standing policy to hold the employer
responsible for controlling exposure to hazards in his or her workplace
and to fulfill this responsibility at no cost to the employee.
Therefore, the financial burden for purchasing and providing personal
protective equipment, including respirators, rests upon the employer
just as it does for all other control measures (e.g., engineering
controls). OSHA believes that in order to assure that employees are
adequately protected, the employer has the responsibility not only to
provide respiratory protection, but also to assure that it is utilized
when necessary. Furthermore, respiratory protection must be donned
prior to entering the above work settings or performing the tasks, for
the period of time that the employee remains in these work settings,
and must not be removed until the employee leaves the work setting or
completes the tasks. In this way, the employee is protected for the
entire period of occupational exposure.
It is not OSHA's intent that each employee be monitored constantly
for compliance; however, the Agency does believe that the employer has
the power to assure that employees follow specific rules. For example,
most employers have requirements that they require employees to follow,
such as reporting to work on time, working a minimum number of hours
per day, notifying the employer when the individual is unable to report
for work, and taking certain precautions to prevent nosocomial
infections. Following these requirements is not left to the employee's
discretion, and employers generally have some process to ensure
conformance with these procedures. Therefore, the Agency believes that
the employer has not only the responsibility, but also the ability, to
assure that respiratory protection is used in accordance with the
requirements of this section.
Paragraph (f)(2)(i) requires that each employer who has any
employee whose occupational exposure is based on entering any of the
work settings or performing any of the tasks described in paragraph
(f)(1) must establish and implement a written respiratory protection
program that assures that respirators are properly selected, fitted,
used, and maintained. The program must include the following elements:
(A) Procedures for selecting respirators for use in the work setting;
(B) a determination of each employee's ability to wear a respirator, as
required under paragraph (g)(3)(ii), Medical Surveillance, for each
employee required to wear a respirator; (C) procedures for the proper
use of respirators; (D) fit testing procedures for tight-fitting
respirators; (E) procedures and schedules for cleaning, disinfecting,
storing, inspecting, repairing, or otherwise maintaining respirators;
(F) training of employees to assure the proper use and maintenance of
the respirators as required under paragraph (h), Communication of
Hazards and Training; and (G) procedures for periodically evaluating
the effectiveness of the program. Written standard operating procedures
are essential to an effective respiratory protection program.
Developing and writing down standard operating procedures require
employers to think through how all of the requirements pertaining to
respirators will be met in their workplace. In addition, this provision
assures that the employer establishes standardized procedures for
selecting, using, and maintaining respirators in the workplace. OSHA's
long-standing position has been that a systematic respiratory
protection program is necessary to provide for consistency in
protection. Guidance that has been developed by an outside party (e.g.,
a respirator manufacturer) on the general use of a particular
respirator would not address the site-specific aspects of the
employer's work setting and would not be an appropriate substitute for
a respiratory protection program.
Paragraph (f)(2)(ii) requires the employer to designate a person
qualified by appropriate training or experience to be responsible for
the administration of the respiratory protection program and for
conducting the required periodic evaluations of its effectiveness. To
assure that the integrity of the respiratory protection program is
maintained through the continuous oversight of one responsible
individual, OSHA is proposing that a qualified person be designated as
responsible for the administration of the program. That individual can
work with a committee or assign responsibility for portions of the
program to other personnel, but the overall responsibility for the
operation of the program remains with the designated person. This
approach ensures coordination of all facets of the program. The level
of training or experience necessary for a designated person has been
left performance oriented since this will vary with the complexity of
the respirator program. However, the person chosen would need to have
sufficient knowledge of respiratory protection and the workplace to
properly supervise the program.
Employers are required, in paragraph (f)(2)(iii), to review and
update the written program as necessary to reflect current workplace
conditions and respirator use. Reviewing and updating will assure that
the program addresses current conditions. The reason OSHA has not set a
schedule for reviewing the program is because conditions may change
frequently in some work settings while remaining relatively stable in
others. Thus, the employer determines the frequency of the review.
However, when an employer is aware of changes in the workplace or
respirator use which could necessitate changes in the written program,
it is not appropriate to delay revising the written program. OSHA's use
of the phrase ``as necessary'' in the requirement is intended to assure
that such changes are incorporated into the written program
expeditiously. As the workplace situation or respirator use
[[Page 54260]]
changes, the program is to be revised. In addition, paragraph
(f)(2)(iv) requires that employers, upon request, make the written
respiratory protection program available to affected employees, their
designated representatives, the Assistant Secretary, and the Director.
This provision also requires that a copy of the program be submitted to
the Assistant Secretary and/or the Director, if requested.
Paragraph (f)(3) sets out the respirator characteristics that must
be satisfied in order to provide employees with a respirator that will
protect them against aerosolized M. tuberculosis. These criteria are
presented in performance-oriented language to provide flexibility in
choice of respirators and have been drawn from CDC recommendations (Ex.
4B). CDC has based these criteria on currently available information
relative to respirators that includes:
* * * (a) data on the effectiveness of respiratory protection
against noninfectious hazardous material in workplaces other than
health-care settings and on an interpretation of how these data can
be applied to respiratory protection against M. tuberculosis; (b)
data on the efficiency of respirator filters in filtering biological
aerosols; (c) data on face-seal leakage; and (d) data on the
characteristics of respirators that were used in conjunction with
administrative and engineering controls in outbreak settings where
transmission to HCWs and patients was terminated (Ex. 4B).
The CDC Guidelines go on to state:
Available data suggest that infectious droplet nuclei range in
size from 1 [micron] to 5 [microns]; therefore, respirators used in
health-care settings should be able to efficiently filter the
smallest particle in this range. Fifty liters per minute is a
reasonable estimate of the highest airflow rate an HCW is likely to
achieve during breathing, even while performing strenuous work
activities (Ex. 4B).
In their 1994 TB guidelines, the CDC states:
Respiratory protective devices used in health-care settings for
protection against M. tuberculosis should meet the following
standard performance criteria:
1. The ability to filter particles 1 um in size in the unloaded
state with a filter efficiency of 95% (i.e., filter
leakage of 5%), given flow rates of up to 50 L per
minute.
2. The ability to be qualitatively or quantitatively fit tested
in a reliable way to obtain a face-seal leakage of 10%.
3. The ability to fit different facial sizes and characteristics
of HCWs [health care workers], which can usually be met by making
the respirators available in at least three sizes.
4. The ability to be checked for facepiece fit, in accordance
with standards established by the Occupational Safety and Health
Administration (OSHA) and good industrial hygiene practice, by HCWs
each time they put on their respirators. (Ex. 4B)
The various respirator provisions that OSHA is proposing rely heavily
on the CDC's aforementioned respirator performance criteria. The
second, third, and fourth CDC criteria are addressed by paragraphs
(f)(3)(i) (A) and (B) and paragraph (f)(5)(ii). Paragraph (f)(3)(i)
requires the employer to select and provide properly fitted negative
pressure or more protective respirators. Negative pressure respirators
must be capable of being: (A) Qualitatively or quantitatively fit
tested in a reliable way to verify a face-seal leakage of no more than
10%; and (B) fit checked by the employee each time the respirator is
donned. Paragraph (f)(5)(ii) requires that employers assure that each
employee who must wear a tight-fitting respirator is fit tested and
passes the fit test. All of these provisions deal with the ability of
the respirator to achieve a good face seal with a particular employee.
Good face fit is critical in assuring proper performance of
respiratory protection. When an employee inhales through a respirator
that does not fit properly, contaminated workplace air can enter the
respirator through gaps and leaks in the seal between the face and the
facepiece. OSHA is requiring the employer to provide each employee who
must wear a respirator with one that fits. To do so, the employer will
have to consider the facial sizes and characteristics in his or her
workplace. It is not necessary for the employer to have respirators of
different sizes of characteristics unless the employees need them. In
other words, an employer may need only one or two styles and sizes.
However, in workplaces where employees have different facial sizes and
characteristics, obtaining proper respirator fit for each employee may
require the fit testing of different mask sizes, possibly from several
manufacturers. Proper respirator fit reduces inhalation leakage through
the face-to-facepiece seal to a minimum.
Once a respirator has been selected based on its ability to achieve
an adequate face-to-facepiece seal, the employee must be able to check
that the respirator is properly seated and sealed to his or her face
each time it is donned. The respirator, therefore, must be able to be
fit checked by the employee. This is a procedure in which the employee
covers the filter surface of the respirator and inhales (negative fit
check) and exhales (positive fit check). If the respirator has an
exhalation valve, this valve must be covered during the positive fit
check. A respirator that is properly sealed will firmly adhere to the
wearer's face upon inhalation due to the negative pressure created
inside the mask. Upon exhalation, the mask should lift slightly off of
the wearer's face to allow air to escape around the face seal.
Employers should be aware that a problem could exist with fit checking
some disposable negative pressure respirators. That is, it is difficult
to cover the entire filter surface, thereby hindering the employee's
ability to perform a proper fit check. At least one respirator
manufacturer has developed a ``fit-check cup'' that covers the filter
surface of their disposable respirator, thereby permitting the user to
more easily perform a fit check. Reusable elastomeric facepiece
respirators utilize filter cartridges that can be covered for
performing a fit check.
CDC's first criteria, regarding filter efficiency, is addressed
under paragraph (f)(3)(ii) of the standard. This provision requires the
employer to select a respirator that will function effectively in the
conditions of the work setting. In addition to meeting the criteria in
paragraph (f)(3)(i) above, the respirator shall be, at a minimum,
either a High Efficiency Particulate Air (HEPA) respirator selected
from among those jointly approved as acceptable by the Mine Safety and
Health Administration (MSHA) and by the National Institute for
Occupational Safety and Health (NIOSH) under the provisions of 30 CFR
part 11, or an N95 respirator certified by NIOSH under the provisions
of 42 CFR part 84.
NIOSH and MSHA are the government agencies charged with testing and
certifying respiratory protective devices. It has always been OSHA's
policy that respiratory protection must be certified by these agencies
before being deemed acceptable. Until recently, HEPA respirators were
the only NIOSH certified negative pressure respirators that met the
CDC's filter efficiency criteria. However, on July 10, 1995, NIOSH's
original respirator certification procedures for air-purifying
particulate respirators, 30 CFR part 11, were replaced by revised
procedures, 42 CFR part 84 (Ex. 7-261). Under the new procedures, all
nonpowered air-purifying particulate respirators are challenged with a
0.3 micron particle (the most penetrating size) at a flow rate of 85
liters per minute. At the conclusion of the test, those respirators
that pass are placed into one of nine classes of filters (three levels
of filter efficiency, with three categories of resistance to filter
efficiency degradation). The three levels of filter efficiency are
99.97%, 99%, and 95%. The three categories of resistance to filter
efficiency degradation are labeled N (not resistant to oil), R
(resistant to
[[Page 54261]]
oil), and P (oil proof). Given these categories, a type N95 respirator
would meet or exceed the filter efficiency performance criteria set
forth in the CDC guidelines which state that a respirator appropriate
for use in protecting against transmission of tuberculosis must be able
to filter particles 1 micron in size in the unloaded state with a
filter efficiency of 95%, given flow rates up to 50 liters
per minute (Ex. 4B). The underlying reasoning for the acceptability of
type N95 respirators is that their filter efficiency of 95% for a 0.3
micron particle will exceed 95% filtering efficiency for a particle
three times as large (i.e., 1 micron). Also, the Agency assumes that
oil aerosols are not likely to be found in the work settings covered by
the standard, and therefore, that the use of a category N respirator
would be sufficient. However, if oil aerosols are present, the employer
would be expected to consider this when selecting the category of
respirator to be used in his or her workplace.
OSHA is permitting the employer to select either a HEPA respirator
certified under 30 CFR part 11 or a respirator certified under 42 CFR
part 84, since particulate respirators certified under both of these
regulations are currently on the market. HEPA respirators are the only
nonpowered particulate respirators certified under 30 CFR part 11 that
meet the CDC guidelines filtration criteria. However, applications for
certification of nonpowered particulate respirators under 30 CFR part
11 are no longer being accepted by NIOSH. Therefore, dwindling stocks
of HEPA respirators certified under that regulation will eventually
lead to their unavailability, and employers will of necessity be
selecting respirators from those approved under 42 CFR part 84.
Paragraph (f)(4)(i) states that the employer shall not permit any
respirator that depends on a tight face-to-facepiece seal for
effectiveness to be worn by employees having any conditions that
prevent such a seal. Examples of these conditions include, but are not
limited to, facial hair that comes between the sealing surface of the
facepiece and the face or facial hair that interferes with valve
function, absence of normally worn dentures, facial scars, or headgear
that projects under the facepiece seal. Paragraph (f)(4)(ii) requires
the employer to assure that each employee who wears corrective glasses
or goggles wears them in such a manner that they do not interfere with
the seal of the facepiece to the face of the wearer. Tight-fitting
facepiece respirators rely on a good face-to-facepiece seal in order to
achieve effective protection. Therefore, the employer must not allow
employees to wear such respirators with conditions that prevent such a
seal. Several studies support the prohibition of facial hair that comes
between the sealing surface of the facepiece and the face (Exs. 7-243,
7-242, 7-182). A study by Skretvedt and Loschiavo found that bearded
subjects wearing half-mask respirators had a median face seal leakage
246 times greater than clean shaven subjects. They go on to state:
Even though a number of bearded individuals did obtain fit
factors above OSHA's minimum requirement for half-mask respirators,
they all failed the qualitative fit test. No relationship was found
between the length, shape, density and texture of beards and the
amount of face seal leakage. Therefore, the only way to identify
bearded negative-pressure respirator wearers obtaining fit factors
above OSHA's minimum requirements would be by performing a
quantitative fit test on them. However, even if quantitative fit
tests are performed on all bearded individuals, another problem must
be faced. The drop in the fit factor experienced when a beard is
present is of such magnitude that no confidence can be placed in the
protection the respirator will provide in the workplace or in future
donnings. All respirator users experience variability from one
donning to the next. This fit variability from donning to donning
occurs due to changes in strap tension, positioning on the face, and
a host of other variables. Donning-to-donning fit variability for
bearded individuals will be even greater since additional variables
will be introduced. A beard is a dynamically changing thing. The
hair length constantly changes as well as the orientation of the
hair in the sealing surface. Beards also accumulate moisture,
natural oils, and debris from the workplace. Even though a
percentage of bearded respirator wearers obtain fit factors slightly
above OSHA's minimum requirements, the tremendous drop in fit factor
resulting from the presence of a beard is such that the safety
factor necessary to accommodate the variability of fit no longer
exists. In summary, although bearded individuals may be able to
achieve fit factors above OSHA's minimum requirements during a
specific quantitative fit test, the drop in protection caused by a
beard coupled with the large fit variability from donning to donning
makes it quite likely that the individual will not obtain the
minimum required protection in the workplace. (Ex. 7-243)
Therefore, while a bearded respirator wearer may be able to obtain
a satisfactory fit on a particular occasion, one cannot assume that the
individual can reliably be expected to achieve that same protection
level each time the respirator is used. Beards grow and change daily.
Each time a respirator is donned there is fit variability. Such
variability in face seal is greatly increased for bearded workers. This
large variability in fit means that a reliable seal cannot be
reasonably expected. This provision should not be construed as a
blanket prohibition on beards among respirator wearers. There are other
types of respiratory equipment such as hoods, helmets and suits that
can be worn by employees with beards, since they do not rely upon a
tight facepiece fit. In addition, this provision refers to facial hair
that interferes with the facepiece seal rather than simply growth of
beard or sideburns. It is the interference with the facepiece seal that
is the concern, not the presence of facial hair. Other conditions such
as the absence of normally worn dentures, facial scarring and cosmetic
surgery change the geometry of the face, thereby changing the ability
of the respirator wearer to achieve a facepiece seal. Facepiece seal
may also be compromised when headgear, temple pieces and nose pieces of
glasses, the edges of goggles and so forth project underneath the
respirator's sealing surface. Both of the above provisions are intended
to eliminate or minimize conditions that jeopardize face-to-facepiece
seal and could permit leakage of outside air into the facepiece.
Paragraph (f)(4)(iii) states that disposable respirators must be
discarded when excessive resistance, physical damage, or any other
condition renders the respirator unsuitable for use. It is not expected
that the filter media of respiratory protective devices would become
occluded with particulates in the work settings covered by this
standard. However, if excessive resistance is noted, the respirator
must be discarded. Also, such respirators must be structurally sound in
order to provide a proper face seal and maintain their effectiveness.
Whenever physical damage occurs (e.g., the respirator is crumpled or
torn; the flexible face seal is damaged; a head strap is broken),
effective functioning cannot be assured and the respirator must be
replaced. In addition, other conditions may render the respirator
unsuitable for use (e.g., the respirator may become contaminated with
blood), thereby requiring discard.
In view of the types of activities carried out and the
environmental conditions encountered in the work settings covered by
this standard, OSHA is proposing to allow the multiple use of
disposable respirators. However, this action should in no way be
construed as setting a precedent for the use of disposable respirators
in any other OSHA standards or in how OSHA views multiple use of
disposable respirators in other work settings. OSHA requests comment on
the approach taken in this proposal toward the reuse of disposable
respirators.
[[Page 54262]]
Paragraph (f)(4)(iv) requires the employer to assure that each
employee, upon donning a tight-fitting respirator, performs a facepiece
fit check prior to entering a work area where respirators are required.
In performing the fit check, the procedures in Appendix B or other
procedures recommended by the respirator manufacturer that provide
equivalent protection to the procedures in Appendix B must be used.
This provision is supported by a recent study by Meyers et al. that
concluded:
* * * for wearers of respirators that have been properly fit by
a recognized fit test, conducting fit checks according to the
manufacturer's instructions can be a useful tool for more
consistently maintaining the quality of respirator donning. (Ex. 7-
233)
The use of such seal checks are a way of helping to assure that
attention is paid to obtaining an adequate facepiece seal each time a
respirator is used.
The standard requires, under paragraph (f)(4)(v), that respirators
be immediately repaired, or discarded and replaced when they are no
longer in proper working condition. Examples of these changes in
condition would be that a strap has broken, the respirator has lost its
shape, or the face seal can no longer be maintained. As discussed
above, respirators must be in good working condition in order to
function effectively. Therefore, it is imperative that they not be used
if they have been impaired in any way. The respirator manufacturers can
supply replacement parts for damaged portions of their elastomeric
respirators. Disposable respirators cannot be repaired and must be
discarded when damaged.
Paragraph (f)(4)(vi) stipulates that the employer shall permit each
employee to leave the respirator use area as soon as practical to: (A)
change the filter elements or replace the respirator whenever the
ability of the respirator to function effectively is compromised or the
employee detects a change in breathing resistance; or (B) wash his or
her face and respirator facepiece as necessary to prevent skin
irritation associated with respirator use. This provision encourages
and facilitates the proper use of respirators by employees by
authorizing employees to take specific actions to assure the effective
functioning of their respirators. This provision is consistent with
requirements in other health standards (e.g., Lead, 29 CFR 1910.1025;
Cadmium, 29 CFR 1910.1027).
Considering the health problems that may be exacerbated with
respirator use and their associated detrimental effects on an employee,
the proposal states in paragraph (f)(4)(vii) that each employee
required to wear a respirator under this section shall be evaluated in
accordance with paragraph (g), Medical Surveillance, of this section to
determine whether any health conditions exist that could affect the
employee's ability to wear a respirator. In addition, paragraph
(f)(4)(viii) states that no employee shall be assigned a task requiring
the use of a respirator if, based upon the employee's most recent
evaluation, the physician or other licensed health care professional,
as appropriate, determines that the employee will be unable to continue
to function adequately while wearing a respirator. If the physician or
other licensed health care professional, as appropriate, determines
that the employee's job activities must be limited, or that the
employee must be removed from the employee's current job because of the
employee's inability to wear a respirator, the limitation or removal
shall be in accordance with paragraph (g)(5)(iii) under Medical Removal
Protection of this section.
Common health problems that could interfere with respirator use
include claustrophobia (an intolerance of feeling enclosed and a
subjective feeling of breathing difficulty), chronic rhinitis, nasal
allergies that would necessitate frequent removal of the respirator to
deal with nasal discharges, and chronic sinusitis. In addition,
difficulties with the use of respirators may arise in employees with
respiratory or cardiac diseases. Respiratory diseases include chronic
obstructive pulmonary disease, emphysema, asthma, and moderate to
severe pneumoconiosis. Cardiac or cardiorespiratory diseases that may
affect respirator wear include any type of congestive heart disease,
other ischemic heart diseases, and hypertension.
As discussed further under paragraph (g)(5)(iv), Medical
Surveillance, of this section, employees who are removed from work due
to the inability to wear a respirator are afforded certain medical
removal protection relative to retention of earnings, seniority, rights
and benefits. The Agency believes that these provisions will encourage
all employees, including those experiencing difficulty with respirator
use, to participate in the Medical Surveillance Program and will
minimize an employee's fear of losing his or her job due to the
possible inability to wear a respirator.
Paragraph (f)(5)(i) requires the employer to perform either
quantitative or qualitative face fit tests in accordance with the
procedures outlined in Appendix B of this section.
Quantitative fit testing is an assessment of the adequacy of
respirator fit by numerically measuring the amount of leakage into the
facepiece. One method of accomplishing this assessment utilizes a
procedure whereby the level of penetration of a test agent of a known
concentration is measured inside the facepiece of the respirator. In
this quantitative fit test procedure, the respirator is worn in a
stable test atmosphere containing a suitable challenge agent. The
adequacy of fit is determined by measuring the actual levels of the
challenge agent, both outside and inside the facepiece of the
respirator. This provides a quantitative assessment of the fit (the fit
factor). Fit testing allows the employer to continue testing different
facepieces until a properly fitting respirator is identified and
selected for the employee. Quantitative fit testing requires the use of
moderately sophisticated testing equipment and is more expensive to
perform than qualitative fit testing, which may reduce its availability
in some work sites. Also, testing services may not be available in all
parts of the country to provide quantitative fit testing services for
small businesses.
Qualitative fit testing does not provide a numerical measure of the
quality of the fit but simply determines whether a respirator fits or
not. The outcome of the test is simply a pass or fail result.
Qualitative fit testing involves the detection of a gas, vapor, or
aerosol challenge agent through subjective means such as odor, taste,
or nasal irritation. If the challenge agent's presence is detected, the
respirator fit is considered to be inadequate. Qualitative fit testing
is more subjective than quantitative testing because it depends on the
individual's ability to detect the test agent.
OSHA believes that while quantitative fit testing has some
advantages, qualitative fit testing conducted in accordance with the
protocols described in Appendix B of this section can generally
accomplish the intent of the standard, which is to assure that each
employee is assigned and wears a respirator that provides a proper fit.
Paragraph (f)(5)(ii) states that the employer shall assure that
each employee who must wear tight-fitting respirator passes a fit test:
(A) at the time of initial fitting; (B) whenever changes occur in the
employee's facial characteristics that affect the fit of the
respirator; (C) whenever a different size or make of respirator is
used; and (D) at least annually thereafter unless the annual
determination required under paragraph (g)(3)(ii)(A), Medical
Surveillance, indicates that the annual
[[Page 54263]]
fit test of the employee is not necessary. This frequency of fit
testing is necessary to assure that factors that may affect the proper
fit of a respirator are detected and necessary adjustments are
performed to assure the integrity of the faceseal. For example, the fit
of respirators is not standardized among manufacturers. Fit testing
would be required, therefore, whenever a different size or make of
respirator is used. In addition, a change in an employee's facial
structure can compromise a respirator's faceseal. Examples of such
changes include loss of weight, cosmetic surgery, facial scarring, and
the installation of dentures or the absence of dentures that are
normally worn by the individual. Therefore, fit testing is required
when any facial changes, such as those mentioned above, occur.
Requiring annual fit testing, unless the annual determination by
the physician or other licensed health care professional indicates that
the annual fit test is not necessary, assures that factors that could
affect respirator fit are detected and the employee's respirator is
adjusted or replaced as necessary. It is OSHA's intent in this
provision that each employee be evaluated annually for respirator fit.
This can be accomplished through either an actual fit test or through a
person-to-person evaluation consisting of a questionnaire and personal
observation by the evaluator carried out under paragraph (g)(3)(ii)(A),
Medical Surveillance, of this section. It should be noted that an
annual determination of respirator fit is required, either through fit
testing or the person-to-person evaluation. The employer may use the
determination of the need for the annual fit test in lieu of an annual
fit test if that determination indicates that a fit test is not
necessary.
One of the criteria that must be satisfied when selecting
respirators is a faceseal leakage of 10% or less. OSHA considers any
respirator that passes a qualitative fit test to meet this criteria.
However, quantitative fit testing necessitates that a particular
numerical value be achieved. Therefore, paragraph (f)(5)(iii) requires
that when quantitative fit testing is performed, the employer shall not
permit an employee to wear a tight-fitting respirator unless a minimum
fit factor of one hundred (100) is obtained in the test chamber. This
value corresponds to a faceseal leakage of 10% or less.
In order to assure that continuing protection is achieved by
reusable and powered air purifying respiratory protective devices, it
is necessary to establish and implement proper maintenance and care
procedures. A lax attitude toward this part of the respiratory
protection program will negate successful selection and fit because the
devices will not deliver the assumed protection unless they are kept in
proper working order. A basic program for assuring proper respirator
function would contain procedures for cleaning, inspection, repair, and
replacement of respirators used in the workplace.
Paragraph (f)(6)(i) requires that the employer clean and disinfect
the respirators using the manufacturer's recommended procedures at the
following intervals: (A) as necessary for respirators issued for the
exclusive use of an employee; and (B) after each use for respirators
issued to more than one employee. Respirators that are not cleaned and
disinfected can cause skin irritation and dermatitis. When more than
one employee uses the same respirator, cleaning and disinfecting after
each use provides the additional benefit of minimizing the respirator's
role as a vehicle for spreading infections (e.g., skin, respiratory)
between employees.
In order to assure continued respirator reliability, they must be
inspected on a regular basis. Therefore, paragraph (f)(6)(ii) requires
that respirators be inspected before each use and during cleaning after
each use. As stipulated in paragraph (f)(6)(iii), such inspections must
include: (A) a check of respirator function, tightness of connections
and condition of the facepiece, head straps, valves, connecting tube,
and cartridges, canisters, or filters; and (B) a check of the rubber or
elastomer parts for pliability and signs of deterioration. In this way,
the employer can assure that the respirator is functioning as intended,
is able to be adjusted by the user, will not allow leakage through
cracks or breaks in the respirator, and is pliable enough to achieve a
proper faceseal.
The standard also contains provisions regarding those respirators
that are found to be deficient upon inspection. Paragraph (f)(6)(iv)
states that respirators that fail to pass inspection must be removed
from service and repaired or adjusted in accordance with the following:
(A) repairs or adjustments to respirators are only to be made with
NIOSH-approved parts designed for the respirator by the respirator
manufacturer and by persons appropriately trained to perform such
operations; (B) only repairs of the type and extent covered by the
manufacturer's recommendations may be performed; and (C) reducing or
admission valves or regulators shall be returned to the manufacturer or
given to an appropriately trained technician for adjustment or repair.
It is self-evident that repairs to respirators should only be performed
by trained individuals, using parts designed for the specific
respirator under repair (not all respirator designs are identical), and
that the individual should not attempt repairs that he or she is not
qualified to undertake or which are not recommended by the
manufacturer.
Another important aspect of assuring appropriate respirator
function is proper storage. Therefore, paragraph (f)(6)(v) stipulates
that the employer assure that respirators are stored in a manner that
protects them from contamination, damage, dust, sunlight, extreme
temperatures, excessive moisture, damaging chemicals and that prevents
deformation of the facepiece or exhalation valve. Proper storage, of
both new respirators and those already in service, assists in
maintaining appropriate respirator function by minimizing conditions
that may cause deterioration of the respirator or filter, interfere
with filter efficiency, change faceseal geometry, and prevent sealing
of valves against inhalation of contaminated air.
As discussed previously, OSHA accepts those respirators certified
by MSHA and NIOSH. Therefore, paragraph (f)(7)(i) requires that
filters, cartridges, and canisters used in the workplace are properly
labeled and color-coded with the NIOSH approval label as required by 30
CFR part 11 or 42 CFR part 84, whichever is applicable, before they are
placed into service. The employer must assure that the existing NIOSH
approval label on a filter, cartridge, or canister is not intentionally
removed, obscured, or defaced while it is in service in the workplace,
as required by paragraph (f)(7)(ii) of this section.
Paragraph (f)(8) requires the employer to review the overall
respiratory protection program at least annually, and conduct
inspections of the workplace as necessary to assure that the provisions
of the program are being properly implemented for all affected
employees. The reason an employer must conduct an annual review and
inspections as necessary is because respirators are utilized as
supplemental and, in some instances, sole protection to prevent
transmission of infectious TB. Therefore, it is of primary importance
to assure proper implementation of the program. The review of the
program must include an assessment of each element required under
paragraph (f)(2) of this section. Once the respiratory protection
program is implemented, the employer retains responsibility for
detecting and
[[Page 54264]]
addressing problems that arise. While the written respiratory
protection program is required to be reviewed and updated under
paragraph (f)(2)(iii) of the standard, the overall review requires that
the employer evaluate actual implementation in the workplace.
Consequently, this provision stipulates inspections of the workplace
and an assessment of each element required under paragraph (f)(2) of
this section to assure proper implementation of the program.
OSHA believes that the proposed provisions regarding respirators
are both appropriate and justified. OSHA seeks comments and data on all
aspects of the proposed respirator requirements.
Paragraph (g) Medical Surveillance
(1) General
The purpose of this section is early detection and prevention of
disease through employee medical histories and physical examinations,
TB skin testing, medical management and follow-up of exposure incidents
and skin test conversions, and medical removal of employees with
suspected or confirmed infectious TB. These requirements are designed
to ensure early detection of TB infections and disease by providing
appropriate medical examinations to enable identification of infection
or disease and to minimize the spread of TB to other employees in the
workplace. Additionally, there are requirements in this section to
assure that employees required to wear respiratory protection are
evaluated to determine their ability to wear a respirator and advised
about the need for annual fit testing. The needs of employees who have
health conditions that might require special attention are also
addressed (e.g., anergy testing, more frequent screening, or further
medical examinations to diagnose TB).
Paragraph (g)(1) calls for medical surveillance to be provided for
each employee who has occupational exposure, as defined in this
standard. Occupational exposure may result in TB infection and the
subsequent development of TB disease. Paragraphs (c)(1)(i, ii),
(exposure determination) require the employer to identify employees
with occupational exposure in the facility. These employees must be
offered medical surveillance.
OSHA believes that early detection and management of exposed
employees helps prevent severe illness and death. According to CDC's
1994 edition of the Core Curriculum on Tuberculosis (Ex. 7-93),
approximately ten percent of the persons infected will develop active
TB disease at some point in their lives (Exs. 4B, 7-50, 7-93). Five per
cent of those infected develop disease within the first two years
following infection and another five percent develop disease later in
their lives. Immunosuppressed persons are at a considerably greater
risk of developing active disease following a TB infection. For
example, individuals infected with HIV and TB have been estimated to
have a 8-10% risk per year of developing active disease (Ex. 7-50).
However, according to the American Thoracic Society:
Clinical trials have shown that daily isoniazid preventive
therapy for 12 months will reduce the risk of developing
tuberculosis in infected persons by about 70 percent and in over 90
percent of patients who are compliant in taking the medications.
(Ex. 5-80)
Most infected people have a positive reaction to the TB skin test
within 2-10 weeks after exposure. Consequently, early detection of
newly infected workers is critical as it permits early initiation of
appropriate therapy and results in a decrease in morbidity and
mortality.
Paragraph (g)(1)(ii) requires that information about the signs and
symptoms of pulmonary tuberculosis disease, a medical history, a
physical examination, TB skin testing, medical management and follow-
up, and if indicated, other related tests and procedures and medical
removal protection if the employee develops infectious TB, be provided
to each employee in work settings described in paragraph (a) Scope who
sustains an ``exposure incident.'' This provision is applicable when
the employee has not been categorized as having occupational exposure
in the employer's Exposure Control Plan. OSHA recognizes that there may
be times when employees who are not ``reasonably anticipated'' to have
occupational exposure to TB may be exposed, (e.g., if engineering
controls break down or an individual with infectious tuberculosis is
unidentified during intake procedures). Employees exposed under such
circumstances incur the risk of TB infection and subsequent disease
(Ex. 7-93) as a result of their work duties. OSHA includes this
provision so that these employees are provided protection.
Paragraph (g)(1)(iii)(A) requires the employer to provide all
medical surveillance at no cost to the employee. This is consistent
with OSHA policy. Providing services at no cost to the employee is an
important factor in successful workplace health and safety programs
because it encourages employee participation in medical surveillance
programs.
Paragraph (g)(1)(iii)(B) requires that all medical surveillance be
provided at a reasonable time and place for the employee. Convenience
of these procedures increases the likelihood of employee participation
in the program. This helps assure that employees receive the full
benefits provided by the standard. OSHA recognizes the need for this
provision and has included it in other standards (e.g., Ethylene Oxide,
29 CFR 1910.1047; Asbestos, 29 CFR 1910.1001; and Bloodborne Pathogens
29 CFR 1910.1030).
Paragraph (g)(1)(iii)(C) states that all medical surveillance is
required to be performed by or under the supervision of a physician or
other licensed health care professional, as appropriate. OSHA has
included in paragraph (j) Definitions, a description of the licensed
health care professional. Such an individual is a physician or other
health care professional who holds a license enabling her or him to
independently provide or be delegated the responsibilities to provide
some or all of the health care services required by this paragraph. In
several states, nurse practitioners may be licensed to independently
perform or supervise the evaluations and procedures required by this
paragraph. In such cases, the requirements of this standard can be
accomplished by those practitioners. In addition, where registered
nurses are licensed to perform or supervise some of the requirements of
this standard, those requirements can be accomplished by those
professionals.
Paragraph (g)(1)(iii)(D) requires that medical surveillance
procedures be provided according to recommendations of the CDC, current
at the time these procedures are performed, except as specified by this
paragraph (g). In other words, employers must comply with paragraph
(g), and with the most current CDC recommendations in providing medical
surveillance. OSHA has set forth what an employer must do to prevent or
minimize occupational exposure in the employer's workplace. However,
CDC, an agency of the U.S. Public Health Service (USPHS), follows the
epidemiology of M. tuberculosis and periodically revises and updates
its guidelines and recommendations to reflect changes in the diagnosis
and treatment of TB. OSHA believes that in addition to meeting the
requirements of paragraph (g), it is appropriate to follow CDC
recommendations, which address screening, medical evaluations, TB skin
test procedures and follow-up (e.g., the administration and
interpretation of skin tests).
OSHA recognizes the dynamic nature of medical knowledge relating to
[[Page 54265]]
tuberculosis and notes that CDC recommendations current at the time of
the standard's publication may differ from recommendations at some
future time when an employee evaluation takes place. Knowledge about
tuberculosis is expanding. For example, the medical response to HIV/
AIDS as related to tuberculosis continues to evolve. These are the
reasons why OSHA has not simply required the employer to comply with a
particular CDC guideline. OSHA believes that incorporating the CDC
recommendations into the standard by reference enhances the quality of
medical surveillance. This assures that employees are provided the most
current and effective evaluation and treatment. Furthermore, the CDC
recommendations provide consistency with regularly updated medical
science and health care practice. A similar provision was included in
the Bloodborne Pathogens standard 29 CFR 1910.1030 and met with
widespread acceptance from the regulated community. The CDC
recommendations cover the specific details of the medical protocols.
Paragraph (g)(1)(iv) requires that all laboratory tests be
performed by an accredited laboratory. Accreditation by a national
accrediting body or its state equivalent means that the laboratory has
participated in a recognized quality assurance program. (For an
explanation of ``accredited laboratory'' see paragraph (j) Definitions
below). This accreditation process is required to assure a measure of
quality control so that employees receive accurate information
concerning their laboratory tests. The accreditation requirement
assures long-term stability and consistency among laboratory test
procedures and interpretations of results. OSHA recognizes the need for
this requirement and has included it in other standards (e.g., Benzene,
29 CFR 1910.1028; Bloodborne Pathogens, 29 CFR 1910.1030).
(2) Explanation of Terms
This paragraph explains the terms used in paragraph (g) Medical
Surveillance. Paragraphs (g)(2)(i) to (g)(2)(vii) include explanations
of the ``medical history'', the ``physical examination (with emphasis
on the pulmonary system, signs and symptoms of infectious tuberculosis,
and factors affecting immunocompetence)'', ``TB skin testing'', the
``face-to-face determination of ability to wear a respirator and need
to be re-fit tested'', ``medical management and follow-up'', ``other
related procedures or tests determined to be necessary'', and ``Medical
Removal Protection''. The applications section, paragraph (g)(3),
describes what must be provided and at what time.
Paragraph (g)(2)(i) describes a medical history, during which the
examiner questions the employee in order to gather information on the
employee's pulmonary system, TB exposure, vaccination, testing and
disease status and factors affecting immunocompetence. A medical
history questionnaire may be used as a starting point for this
discussion. OSHA believes that a medical history is essential for
interpreting the TB skin test results, which are also required by this
paragraph (g). The CDC Core Curriculum states:
TB skin testing is a useful tool, but is not perfect. Several
factors can affect the skin test reaction: for example, infection
with mycobacteria other than M. tuberculosis and vaccination with
BCG. These factors can lead to false-positive reactions * * * Other
factors, such as anergy, can lead to false-negative reactions. (Ex.
7-93).
Therefore, the medical history is used to assist in interpreting
the TB skin test results. The medical history also provides information
regarding the employee's potential for increased risk if exposed to
tuberculosis. Based on this information, discussions between the
employee and the examiner regarding the employee's increased risk can
assist the employee in decision-making.
Paragraph (g)(2)(ii) describes the physical examination. The
physical examination is to emphasize the pulmonary system, signs and
symptoms of active TB disease, and factors affecting immunocompetence.
Such an examination assists the examiner in detecting evidence of
active disease (e.g., rales), differentiating TB disease from other
causes of cough or other signs/symptoms associated with TB disease, and
ascertaining whether signs are present that are compatible with an
immunocompromising health condition. The physical examination is also
required when an employee has signs or symptoms of TB or after a TB
skin test conversion and at other times, if indicated.
That the pulmonary system is emphasized in both the medical history
and physical examination assures that the employee is evaluated with
specific attention to the most common site of infectious TB. Although
extrapulmonary tuberculosis can occur (e.g., in bone, meninges of the
brain, and draining abscesses), it is not usually a source of infection
for others. The language ``with emphasis on the pulmonary system'' is
used to indicate that while the history and physical examinations
evaluate the health of the patient as a whole, particular emphasis
should be placed on the pulmonary system.
Paragraph (g)(2)(iii) explains the required TB skin testing. TB
skin testing is the cornerstone for early detection of TB transmission
among exposed workers. The American Thoracic Society notes that:
Although currently available TB skin tests are substantially
less than 100% sensitive and specific for detection of infection
with M. tuberculosis, no better diagnostic methods have yet been
devised. (Ex. 5-4)
The TB skin test is an important tool that is useful in identifying
employees who may be eligible for appropriate, early treatment;
initiating contact investigations; and evaluating the effectiveness of
the facility's control program. The requirement for TB skin testing is
supported by AHA (Exs. 7-61, 7-29 ), APIC (Ex. 7-30), AIHA (Ex. 7-170)
and the CDC 1994 Core Curriculum which states, ``TB screening should be
done in groups for which rates of TB are substantially higher than the
general population.'' [Ex. 7-93]. In this document, CDC specifically
mentions screening for health care workers, staff of long term care
facilities, correctional facilities, hospices, drug treatment centers,
and nursing homes.
Paragraph (g)(2)(iii) describes the requirement for TB skin
testing. TB skin testing, which only applies to employees whose TB skin
test status is not known to be positive, includes anergy testing if
indicated, and consists of an initial 2-step protocol for each employee
who has not been previously skin tested and/or for whom a negative test
in the past 12 months cannot be documented. If the employer has
documentation that the employee has had a negative TB skin test within
the past 12 months, that test may be used to fulfill the skin testing
portion of the initial medical surveillance requirements. For example,
if an employer has a new or existing employee for whom: (1) a TB skin
test has not previously been performed, or (2) a negative skin test
result within the past 12 months that cannot be documented, the
employer is required to provide an initial two-step skin test for the
employee. Conversely, if the employer can document a negative skin test
result from a test performed on the employee within the past 12 months,
that test can be used to fulfill the initial skin testing requirement
of this section. Subsequent periodic retesting of the employee is to be
performed in accordance with paragraph (g)(3), as discussed below.
It is important for the employer to determine the current TB skin
test status
[[Page 54266]]
of employees prior to their initial assignment to a job with
occupational exposure. This ``baseline'' status can then be used to
evaluate changes in the employees' TB skin test.
In their 1992 guidelines, the American Thoracic Society recommended
the following:
Individuals at high risk for TB should have a TB skin test at
least once to assess their need for preventive therapy and to alert
the health care providers of those with positive skin tests of this
medical problem. In institutional settings, baseline information on
the TB skin test status of staff and residents is a means of
identifying candidates for preventive therapy as well as determining
whether transmission of TB is occurring in the facility. For this
reason, TB skin testing upon employment or upon entry should be
mandatory for staff and residents * * * (Ex. 5-80)
Previous BCG vaccination is not a contraindication for skin
testing. In its 1994 guidelines, the CDC states:
During the pre-employment physical or when applying for hospital
privileges, HCWs who have the potential for exposure to M.
tuberculosis [sic], including those with a history of BCG
vaccination, should have baseline PPD skin testing performed * * *
BCG vaccination may produce a PPD reaction that cannot be
distinguished reliably from a reaction caused by infection with M.
tuberculosis. For a person who was vaccinated with BCG, the
probability that a PPD test reaction results from infection with M.
tuberculosis increases (a) as the size of the reaction increases,
(b) when the person is a contact of a person with TB, (c) when the
person's country of origin has a high prevalence of TB, and (d) as
the length of time between vaccination and PPD testing increases.
For example, a PPD test reaction of 10 mm probably can be
attributed to M. tuberculosis in an adult who was vaccinated with
BCG as a child and who is from a country with a high prevalence of
TB. (Ex. 4B)
CDC does not state that BCG vaccination negates the need for baseline
and periodic skin testing but does state that skin tests on vaccinated
individuals need to be interpreted carefully. OSHA's proposed rule is
consistent with the CDC Guidelines on this point. PPD testing is thus
not contraindicated for BCG vaccinated employees; however, such prior
vaccination does mean that other factors, such as the age of the
employee and the extent of induration, must be considered in
interpreting the results.
The purpose of performing a two-step test is to correctly identify
the baseline TB skin test status of those employees who are infected
with TB but whose sensitivity to the tuberculin testing material may
have waned over the years. This procedure enhances the proper
interpretation of subsequent positive TB skin test results and is based
upon current CDC and American Thoracic Society recommendations (Exs. 5-
80, 6-15, 7-52, 7-93, 7-169).
Two-step testing requires an employee to be tested initially and,
if the test results are negative, to be tested again within 1-3 weeks.
This second test stimulates or ``boosts'' the body's response to the
testing material and results in a more valid reaction. For example, an
employee who has not been recently tested but who is infected with TB
from an earlier exposure may fail to respond to this current test
because his or her immune response has waned over time. However, a
second test of this employee will produce a positive TB skin test that
more accurately reflects his or her true TB skin test status. Thus, the
initial use of a two-step testing procedure ensures that the baseline
TB skin test is an accurate reflection of the employee's TB status and
will reduce the likelihood of misinterpreting a ``boosted'' reaction on
subsequent tests as a conversion. Two-step testing is also appropriate
for individuals who have been BCG vaccinated, since these individuals
can exhibit a boosted reaction. Therefore, two-step testing of BCG
vaccinated individuals can be used to determine their baseline status,
although the skin test results must be interpreted in light of their
previous BCG vaccination.
The two-step testing procedure does not identify those persons who
are truly anergic and, therefore, are not capable of mounting a typical
immune response to the test material. Evaluation of adequate immune
response, when determined to be necessary by the physician or other
licensed health care professional, as appropriate, is determined
through anergy testing, and this is provided for in the explanation of
TB skin testing in paragraph (g)(2)(iii).
The CDC recommendations are the guiding documents for TB skin test
protocols. By referring the employer to these recommendations in
Paragraph (g)(1)(iii)(D), OSHA allows for future changes in protocols
and procedures that result from continuing research. Consistent with
the CDC guidelines (Exs. 3-33, 3-35, 3-32, 6-15), the American Thoracic
Society recommends:
The Mantoux test with 5 Tuberculin Units (TU) of PPD may be used
as a diagnostic aid to detect tuberculous infection and to determine
the prevalence of infection in groups of people. (Ex. 5-4)
Proper administration of a TB skin test results in a reaction
described as a classic example of a delayed (cellular) hypersensitivity
reaction. This reaction indicates infection with mycobacterium, most
commonly M. tuberculosis. The reaction characteristically begins in 5-6
hours, is maximal at 48-72 hours, and subsides over a period of days
(Ex. 5-4).
Proper administration and interpretation of the test is critical
and can be complex. In 1990, the American Thoracic Society revised the
criteria for interpreting the TB skin test (Ex. 5-4). Information such
as the health status of the tested employee, history of BCG
vaccination, recent close contact with persons with active TB, chest x-
ray results, and other factors must be considered when interpreting the
TB skin test results. CDC has established criteria for a TB skin test
conversion; that is, when an employee's TB skin test results change
from negative to positive, indicating a recent TB infection (Ex. 4-B).
Because of the complexity in properly administering and
interpreting TB skin tests, it is essential that only trained
individuals perform this function. For this reason, TB skin testing is
to be administered and interpreted by or under the supervision of a
physician or other licensed health care professional as appropriate and
according to CDC recommendations. This language allows employers to
chose from a variety of health care professionals who can administer
and interpret TB skin tests. OSHA is aware that in some worksites,
employees have been allowed to read and interpret their own skin test
results. A surveillance system that allows self-reading and
interpretation of TB skin tests can be problematic. With regard to
interpretation of TB skin test results, the American Thoracic Society
states:
Intelligent interpretation of skin test results requires a
knowledge of the antigen used (tuberculin), the immunologic basis
for the reaction to the antigen, the technique(s) of administering
and reading the test, and the results of epidemiologic and clinical
experience with the test. (Ex. 5-4)
In its 1994 Core Curriculum on Tuberculosis (Ex. 7-93), CDC
describes the complexities of interpreting the induration resulting
from TB skin testing. A number of factors can affect the size of a TB
skin test induration relative to whether or not the test should be
interpreted as being positive. For example, induration of 5 mm or more
is classified as positive for persons with known or suspected HIV
infection, while an induration must be 10 mm to be classified as
positive in persons who are foreign-born in high prevalence countries.
An induration of 15 mm or more is classified as positive in certain
other situations. In addition, TB skin
[[Page 54267]]
testing can result in both false positive and false negative results.
Clearly, interpreting TB skin test results requires professional
expertise and must be performed by or under the supervision of a
physician or other licensed health care professional, as appropriate,
by an individual with training and experience in performing the test
and interpreting the result. Proper use of the TB skin test as a
medical surveillance tool will require two visits to the health care
professional: one to receive the test and one to read/interpret the
test results. However, considering the critical importance of this
element, OSHA believes that allowing employees to read and interpret
their own tests or allowing their peers to do so (unless they meet the
criteria discussed above) compromises the quality and accuracy of the
testing procedure.
Paragraph (g)(2)(iv) describes the determination of each employee's
ability to wear a respirator and of his or her need for re-fit testing
for employees required to wear a respirator. This face-to-face
determination includes a verbal exchange between the employee and the
examiner regarding the employee's health factors such as illness or
injuries, that may impact his or her ability to wear a respirator (e.g.
vascular or heart disease, asthma, claustrophobia, facial structure
defects, certain skin conditions, etc.) (Ex.7-64). Based on this
history and the observation of the employee, the need for further
testing or physical examinations for the ability to wear a respirator
can be determined. In addition, assessment of the need for re-fit
testing is to be performed, which assures that the examiner consider
whether re-fit testing is needed. OSHA has included a note stating that
the determination of the need for re-fit testing may only be performed
after the required initial fit test of the employee and cannot be used
in lieu of any other required fit tests, as, for example, when a
different size or make of respirator is used.
Paragraph (g)(2)(v) explains that medical management and follow-up
include diagnosis, and, where appropriate, prophylaxis and treatment
related to TB infection and disease. The employer must provide medical
management and follow-up for occupationally exposed employees with skin
test conversions [paragraph (g)(3)(i)(D)], or those who undergo an
exposure incident whether or not they are categorized as occupationally
exposed [paragraphs (g)(1)(ii) and (g)(3)(i)(C)]. In addition, any time
an occupationally exposed employee develops signs and symptoms of
infectious tuberculosis, medical management and follow-up are required
[paragraph (g)(3)(i)(B)]. John E. McGowan addressed follow-up in the
1995 article entitled ``Nosocomial Tuberculosis: New Progress in
Control and Prevention,'' published in Clinical Infectious Diseases. He
states,
If the PPD skin testing program for health care workers is to be
useful, several steps are crucial. * * * The institution also must
make sure that the occupational health service undertakes careful
follow-up of workers found to have positive TB skin tests or
tuberculosis disease. This follow-up should include counseling,
careful monitoring of therapy (when prescribed) until its completion
and evaluation of fitness to return to work. (Ex. 7-248).
Paragraph (g)(2)(vi) explains that other related tests and
procedures are any TB-related tests and procedures determined to be
necessary by the physician or other licensed health care professional,
as appropriate. These procedures or tests could include chest
radiographs, sputum smears, or other testing determined to be necessary
to make an assessment, a diagnosis, or medically manage the employee.
An example of a program that integrates testing and examinations was
given at the 1994 meeting of the Society for Occupational and
Environmental Health, by Carol Murdzak who presented the University of
Manitoba's Medical Surveillance program. Her presentation, entitled
``Conducting a Medical Surveillance Program to Prevent and Control
Transmission of TB in a Health Care Institution'' demonstrates the use
of skin testing and general review of health status for employee
surveillance. Results of TB skin testing and the review of health
status determine the need for chest x-ray and further medical
evaluation in this program (Ex.7-169).
(3) Application
Medical examinations in the form of medical histories, physical
examinations, TB skin testing and other related tests and procedures
are necessary in order to promptly identify and treat employees with
infectious tuberculosis.
Paragraph (g)(3), Application, specifies what an employer must
provide. In each situation set forth in paragraph (g)(3), the employer
must provide medical examinations, tests and procedures as specified.
Some of the provisions are offered only ``if indicated,'' which means
that the physician or other licensed health care professional, as
appropriate, has determined that further tests or procedures are
needed. For example, an employee who has no history of illness or being
immunocompromised and whose TB skin test is negative at the time of
initial assignment is not required to be offered a physical examination
unless the examiner determines that a physical examination is
indicated. However, if at the time of annual skin test, the employee
has a skin test conversion, a physical examination is required.
Paragraph (g)(3)(i)(A) requires that, before the time an employee
is initially assigned to a job with occupational exposure (or within 60
days from the effective date of the standard for employees already
assigned to jobs with occupational exposure), the employee be provided
with a medical history, TB skin testing, and, if indicated, a physical
examination and other related tests and procedures.
OSHA requires the initial medical history to assist in assessing
the employee's health. This information will provide a baseline health
status that can be used to evaluate (1) whether the employee has a pre-
existing condition that may be exacerbated by occupational exposure to
TB and (2) any future health conditions that may arise that are
relevant to occupational exposure to TB.
OSHA does not believe that an initial physical examination for all
occupationally exposed employees is necessarily warranted. However, the
Agency does believe that a physical examination, if determined to be
indicated by the examiner based on the medical history and TB skin test
results, is useful and effective.
The note to paragraph (g)(3)(i)(A) specifies that if an employee
has had a medical examination within the twelve (12) months preceding
the effective date of the standard and the employer has documentation
of that examination, only the medical surveillance provisions required
by the standard that were not included in the examination need to be
provided. The Agency realizes that employees may have received at least
some of the elements of the required medical surveillance provisions
shortly before the effective date of the standard. In these situations,
a full TB examination would not need to be repeated.
In addition, the proposed standard allows the baseline TB skin
testing status of an employee to be established by documentation of a
TB skin test that was administered within the previous 12 months. For
example, if an employee has a written record of a TB skin test within
the last 12 months, that information can be used to document the
employee's baseline TB skin test status and another TB skin test at the
[[Page 54268]]
time of the initial medical examination is not necessary. When
utilizing results from a previous medical examination and skin test to
fulfill the initial medical surveillance requirements, the employer
must use the date(s) of the previous medical exam and skin test to
determine the date(s) of the employee's next medical examination and
skin test. In no case shall the interval between the previous
examination and skin test and the next examination and skin test exceed
12 months. These provisions are designed to avoid unnecessary testing
of employees and do not compromise the quality of the medical
surveillance.
Information (e.g., medical history) obtained from a medical
examination in the past 12 months is unlikely to change within this
span of time. However, this may not be the case with regard to previous
skin testing results. While OSHA is proposing to accept a skin test
performed within the past 12 months as a substitute for performing an
initial baseline skin test, an employer utilizing a new employee's
negative skin testing result obtained more than 3 months prior to
beginning the new job may be uncertain as to the source and time of
infection if the employee tests positive at his or her next skin test.
More specifically, conversion normally occurs within 3 months of
infection. Therefore, an employee would have been negative at his or
her last skin test, e.g., 7 months previously, and have been infected
just after the skin test and subsequently converted. In such a case, an
employer may rely on the previous negative skin test as the baseline
does not need to test the new employee until 5 months later (i.e.,
annual skin test frequency), at which time the employee would test
positive and be identified as a converter. In this situation, the new
employer would not be able to determine if the employee's conversion
had occurred as a result of exposure occurring previous to hire or from
exposure in his or her current work setting. Regardless of the source
of the conversions, the employer would be required by the standard to
initiate medical management and a follow-up investigation, which might
also entail skin testing other employees in the worksite to determine
if other conversions had taken place, a step that would not be
necessary if the employee had been correctly identified as positive
upon entry into the workplace. In view of this, employers may choose to
perform an initial baseline skin test on each new employee before the
employee enters the work setting.
Once an employee is on the job, paragraph (g)(3)(i)(A) requires
employers to periodically retest employees who have negative TB skin
tests in order to identify those employees whose skin test status
changes, indicating that they have been infected. Because the baseline
TB skin test provides only a ``snapshot'' of the TB skin test status of
the employee and because exposure and subsequent infection can occur at
any time, periodic testing is necessary. The American Thoracic Society
recommends:
* * * follow-up skin-testing should be conducted on at least an
annual basis among the staffs of TB clinics, health care facilities
caring for patients with HIV infection, mycobacteriology
laboratories, shelters for the homeless, nursing homes, substance-
abuse treatment centers, dialysis units, and correctional
institutions. (Ex. 5-80)
When TB exposure results in infection, early identification allows
employees to have options regarding prophylactic treatment, thereby
reducing the likelihood that the infection will progress to disease.
OSHA recognizes the importance of periodic testing to monitor the
status of employee's skin test results. In their 1994 Guidelines for
Preventing the Transmission of Tuberculosis in Health-Care Facilities,
the CDC recommends that the frequency of PPD skin testing of employees
be based upon the individual facility's risk assessment in conjunction
with the criteria put forth by the CDC (Ex. 4B). For situations that
meet certain CDC criteria, CDC recommends that employees receive a
repeat TB skin test every 3 months, six months or annually, depending
upon the risk assessment.
OSHA's proposed standard does not require a risk assessment of the
type described by CDC and would extend coverage to worksites other than
``health-care facilities'' as described in the CDC document (Ex. 4B).
Consequently, OSHA is proposing that repeat TB skin test be performed
every 6 months or annually, depending upon the exposure determination.
This testing frequency is expected to be both practical and effective
in early identification of skin test conversions in the various
worksites described in the Scope. The requirements for more frequent TB
skin tests (e.g., 3 months after an exposure incident, or if deemed
necessary by a licensed health care professional) ensures that
employees' health is not compromised.
An exemption to this annual testing is permitted for an employer
who can demonstrate that his or her facility or work setting: (1) Does
not admit or provide medical services to individuals with suspected or
confirmed infectious TB, (2) has had no cases of confirmed infectious
TB in the past 12 months, and (3) is located in a county that, in the
past two years, has had 0 cases of confirmed infectious TB reported in
one year and fewer than 6 cases of confirmed infectious TB reported in
the other year. In these settings only a baseline TB skin test is
required. This is discussed earlier under paragraph b, application.
Paragraph (g)(3)(i)(B) requires that, when an employee has signs or
symptoms of TB, either observed or self-reported, the employee be
provided a medical history, physical examination, TB skin testing,
medical management and follow-up, and other related tests and
procedures determined to be necessary. CDC states that the presence of
signs or symptoms of tuberculosis in the employee requires prompt
medical evaluation (Ex. 7-52, 7-93), and such evaluation provides an
opportunity for initiating drug therapy. Furthermore, identifying those
with infectious pulmonary TB disease enables the employer to remove
them from the workplace, preventing exposure of other employees.
Paragraph (g)(3)(i)(C) requires that when an employee incurs an
exposure incident, a medical history, TB skin testing, medical
management and follow-up, and, if indicated, a physical examination and
other related tests and procedures be provided. Evaluation and follow-
up after each exposure incident help detect any resultant infections,
as well as prevent infection in other employees, benefitting the health
of all employees.
Following exposure, infected workers will usually develop a
positive response to a TB skin test (Exs. 7-50, 7-93, 5-4). In certain
cases, workers may also display signs or symptoms compatible with
tuberculosis disease such as complaints of persistent cough (over 3
weeks in duration), bloody sputum, night sweats, weight loss, loss of
appetite or fever. Use of the TB skin test has been recognized as a
tool in the early identification of infection and for disease
surveillance and follow-up. In paragraph (g)(3)(i)(C), the proposed
standard also requires employers to provide testing for employees as
soon as feasible after an exposure incident, unless a negative TB skin
test has been documented within the preceding 3 months. If this
baseline skin test is negative, another TB skin test shall be repeated
3 months after the exposure incident.
In order to accurately determine if an exposure incident has
resulted in infection, the employer must first know the baseline skin
test status of the affected employee(s) at the time of the exposure
incident. Typically, skin test conversion can be documented
approximately 2-10 weeks following
[[Page 54269]]
infection (Ex. 7-52). Consequently, it can be reasonably assumed that a
negative TB skin test within the three months prior to the incident is
sufficiently indicative of the employee's status at the time of the
exposure incident.
For those employees who do not have a documented negative skin test
within the past three months, the employer must determine their TB skin
test status as soon as feasible after the exposure incident. The
requirement of ``as soon as feasible'' in the provision puts the
employer under the obligation of performing the TB skin test quickly,
i.e., before infection resulting from the exposure would be manifested
as a conversion. This assures that a true indication of the employee's
skin test status at the time of the incident is obtained.
The purpose of the initial TB skin test following an exposure
incident is to establish the TB skin test status of the employee(s) at
the time of the incident. From this baseline, changes in TB skin test
status can be identified. This initial test would not detect infection
resulting from the exposure, since there would not have been sufficient
time for conversion to occur. Hence, the employer is required to
provide a repeat TB skin test three months after the exposure incident
to determine if infection has occurred. This requirement reflects
current CDC recommendations (Ex. 4B).
Paragraph (g)(3)(i)(D) requires that when an employee has a TB skin
test conversion, the employee receive a medical history, a physical
examination, medical management and follow-up, and other tests and
procedures determined to be necessary. This provision assures that
employees with skin test conversions receive appropriate evaluation for
preventive therapy and for infectious tuberculosis. OSHA included the
provision for early identification of disease since, as the CDC has
stated in their guidelines, infectious tuberculosis disease can be
prevented by the early treatment of tuberculosis infection.
In paragraph (g)(3)(i)(E), the proposed standard requires employers
to provide TB skin testing within 30 days prior to termination of
employment. The rationale for this requirement is two-fold. First, this
requirement permits employees whose employment is terminated after an
unrecognized exposure incident, but before their next regularly
scheduled TB skin test, to determine their current (exit) TB skin test
status. OSHA recognizes that in some instances employees may be in the
process of converting from negative to positive TB skin test results at
the time of the exit testing and that some of these cases will be
missed. Also missed will be employees who decline testing or who vacate
their position immediately or without notice. While such situations are
possible, the Agency believes that these occurrences would be rare.
Secondly, by detecting recent conversions, appropriate steps can be
taken by the employer to investigate the cause of the exposure. This
helps prevent future exposures in those areas or situations where the
exiting employee's infection may have occurred.
Paragraph (g)(3)(i)(F) requires that a medical history, physical
examination, TB skin testing, determinations of the employee's ability
to wear a respirator, medical management and follow-up or other related
tests and procedures be conducted at any other time determined
necessary by the physician or other licensed health care professional,
as appropriate. This allows the physician or other licensed health care
professional, as appropriate, to recognize the individual differences
in employees' medical status and response to TB infection and increase
the frequency or content of examination as needed. Some workers who
have certain health conditions may need more frequent evaluation (Ex.
4B). For example, individuals who have a condition that may interfere
with an accurate interpretation of TB skin test results (e.g., the
development of test anergy in an employee who is on chemotherapy for
cancer treatment), may warrant more frequent evaluations because of the
high risk for rapid progression to TB disease if he or she becomes
infected. (Ex. 4B)
Paragraph (g)(3)(ii) sets forth provisions regarding employees who
wear respirators. Paragraph (g)(3)(ii)(A) requires that a face-to-face
determination of the employee's ability to wear the respirator be
accomplished before initial assignment to a job with occupational
exposure (or within 60 days of the effective date of the standard) and
at least annually thereafter. As discussed above under explanation of
terms, this is a verbal exchange to assess health factors that could
affect the employee's ability to wear a respirator. An initial
determination is made before assignment to a job requiring respirator
use to assure that the employee's health factors have been properly
evaluated prior to incurring exposure to M. tuberculosis. This
determination must also be made annually to assure that no health
conditions have arisen that might limit an employee's ability to wear a
respirator.
Such conditions may arise and be noted prior to the annual
determination. For example, the employee may experience unusual
difficulty while being fitted or while using the respirator. In these
situations, it is not appropriate to wait until the annual
determination. Therefore, paragraph (g)(3)(ii)(B) requires that a face-
to-face determination of the employee's ability to wear a respirator,
including relevant components of a medical history and, if indicated, a
physical examination and other related tests and procedures, be
provided whenever the employee experiences unusual difficulty while
being fitted or while using a respirator.
Paragraph (g)(3)(iii) requires employers to provide TB skin tests
every 6 months for each employee who enters AFB isolation rooms or
areas, performs or is present during the performance of high-hazard
procedures, transports or is present during the transport of an
individual with suspected or confirmed infectious TB in enclosed
vehicles, or works in intake areas where early identification is
performed in facilities where 6 or more individuals with confirmed
infectious TB have been encountered within the past 12 months. OSHA
believes that employees who perform these activities are exposed more
intensely and frequently to individuals with suspected or confirmed
infectious tuberculosis and should, therefore, be tested more
frequently.
(4) Additional Requirements
Paragraph (g)(4) (i) through (iv) contain the additional
requirements an employer must meet. Paragraph (g)(4)(i) requires that
the physician or other licensed health care professional, as
appropriate, verbally notifies the employer and the employee as soon as
feasible if an employee is determined to have suspected or confirmed
infectious tuberculosis. In this way an infectious employee can be
removed from the workplace, thereby minimizing occupational exposure
for other workers. Paragraph (g)(7)(i), Written Opinion, allows 15 days
before the employer must provide the employee with the written opinion
of medical evaluations from the physician or other licensed health care
professional, as appropriate. In situations where an employee is
determined to be potentially infectious, this time period leads to
unnecessary delays in removal from the workplace and disease treatment.
Therefore, OSHA requires the verbal notification to expedite treatment
[[Page 54270]]
and prevent spread of disease to other employees.
The proposed standard, in paragraph (g)(4)(ii), requires the
employer to notify each employee who has had an exposure incident when
the employer identifies an individual with confirmed infectious TB who
was previously unidentified. For example, if a newly admitted patient
undergoes diagnostic and therapeutic evaluation for suspected pulmonary
malignancy, and the diagnosis of infectious tuberculosis is not made
until several days after hospitalization, all hospital staff who have
had exposure must be identified and provided TB skin test and follow-
up. OSHA intends to assure that employees are provided with
opportunities for early detection of tuberculosis infection. These
provisions are consistent with the general purpose of tuberculosis
medical surveillance as recommended by the CDC, and they are included
to assist all employees in receiving the full benefits provided by the
standard.
Determination of the drug susceptibility of the M. tuberculosis
isolate from the source of an exposure incident resulting in a TB skin
test conversion is required by paragraph (g)(4)(iii) unless the
employer can establish that such a determination is infeasible.
Information regarding drug susceptibility assists the examiner in
deciding the most effective treatment therapy for the exposed employee,
particularly if the source is a drug resistant strain of M.
tuberculosis. Drug susceptibility testing of the source isolate is
recommended by CDC (Ex. 4B). OSHA includes the provision regarding
infeasibility because certain TB skin test conversions may involve
unknown exposure sources. This can make identification of the isolate
and therefore drug susceptibility testing infeasible or even
impossible. It is the responsibility of the employer to establish that
this is infeasible, if such is the case. Employers must make a good
faith effort to identify M. tuberculosis isolates and obtain the drug
susceptibility testing.
Paragraph (g)(4)(iv) requires the employer to investigate and
document the circumstances surrounding an exposure incident or TB skin
test conversion and to determine if changes can be instituted that will
prevent similar occurrences in the future.
The provision assures that employers obtain feedback regarding the
circumstances of employee exposures and use the information to
eliminate or decrease specific circumstances leading to exposure. For
example, exposure incident investigation shows that an employee was
exposed to tuberculosis as a result of recirculation of air containing
infectious droplet nuclei. Further investigation shows inadequate local
or general ventilation in the workplace. The employer can now repair
the ventilation system and prevent future exposure incidents. Another
example of corrective measures may be including a stronger training
emphasis on certain procedures where proper work practices might have
decreased the likelihood of transmission of tuberculosis. Employers can
obtain further guidance regarding investigations for TB skin test
conversions and exposure incidents in health care workers by reading
the 1994 CDC guidelines.
(5) Medical Removal Protection
Paragraph (g)(5)(i) requires that employees with suspected or
confirmed infectious tuberculosis be removed from the workplace until
determined to be non-infectious according to current CDC
recommendations. Infectious TB is contagious and removal is essential
for the protection of other workers. An employee's ``infectiousness''
is determined by the physician or other licensed health care
professional, as appropriate, who informs the employer as required in
paragraphs (g)(4)(i) and (g)(7) of this section.
Paragraph (g)(5)(ii) states that for employees removed from the
workplace under paragraph (g)(5)(i), the employer shall maintain the
total normal earnings, seniority, and all other employee rights and
benefits, including the right to former job status, as if the employee
had not been removed from the job or otherwise been medically limited
until the employee is determined to be noninfectious or for a maximum
of 18 months, whichever comes first. Paragraph (g)(5)(iii) provides
medical removal protection for employees removed from the workplace
under paragraph (f)(4)(viii) of Respiratory Protection. The provision
requires the employer to transfer the employee to comparable work for
which the employee is qualified or can be trained in a short period (up
to 6 months), where the use of respiratory protection is not required.
OSHA requires that if no such work is available, the employer shall
maintain the employee's total normal earnings, seniority, and all other
employee rights and benefits until such work becomes available or for
18 months, whichever comes first.
The requirement referring to the employee's right to return to his
or her former job is not intended to expand upon or restrict any rights
an employee has or would have had, to a specific job classification or
position under the terms of a collective bargaining agreement. Where
the employer removes an employee from exposure to tuberculosis, the
employee is entitled to full medical removal protection benefits as
provided for under the standard.
The medical removal requirement is an indispensable part of this
standard. The medical removal protection helps assure that affected
employees participate in medical surveillance and seek appropriate
care. If employees fear losing their jobs as a result of their medical
condition they may attempt to hide the illness, thereby infecting many
more workers and other people and jeopardizing their own health. The
requirement for medical removal assures that an infectious employee
will not be terminated, laid off, or transferred to another job
(possibly at a lower pay grade) upon returning to work. Consequently,
this protection should reduce reluctance on the part of the employee to
participate in medical surveillance. The employee's health will be
protected and the health of co-workers and others who come into contact
with that employee will be protected, also.
OSHA believes that the cost of protecting worker health to the
extent feasible is an appropriate cost of doing business since
employers are obligated by the OSH Act to provide safe and healthful
places of employment. Consequently, the costs of medical removal, like
the costs of respirators and engineering controls, are borne by
employers rather than individual workers.
If a removed employee files a claim for workers' compensation
payments for a tuberculosis-related disability, then the employer must
continue to provide medical removal protection benefits pending
disposition of the claim. To the extent that an award is made to the
employee for earnings lost during the period of removal, the employer's
medical removal protection obligation may be reduced by such amount.
The employer's obligation to provide medical removal protection
benefits to a removed employee may be reduced to the extent that the
employee receives compensation for earnings lost during the period of
removal either from a publicly or employer-funded compensation program,
or receives income from employment with another employer which was made
possible by virtue of the employee's removal.
Medical removal should not be viewed as an alternative to primary
control (prevention) of workers' exposure to tuberculosis; rather, it
should be used as a secondary means of
[[Page 54271]]
protection, where other methods of control have failed to protect. The
stipulation of an 18 month time period of protection is consistent with
other OSHA standards (e.g., Cadmium, 29 CFR 1910.1027; Lead in
Construction, 29 CFR 1926.62). The provision of medical removal and the
costs associated with the program may indirectly provide employers with
economic incentives to comply with other provisions of the standard. It
can be expected that the costs of medical removal will decrease as
employer compliance with other provisions of the standard increases.
(6) Information Provided to Physician or Other Licensed Health Care
Professionals
Paragraph (g)(6)(i) requires the employer to assure that the health
care professionals responsible for the medical surveillance receive a
copy of this regulation. OSHA believes it is the employer's
responsibility to inform the health care professionals responsible for
medical surveillance of the requirements of this standard. This will
help assure that these individuals are aware of and implement the
requirements. This provision is included in other OSHA standards (e.g.,
Benzene, 29 CFR 1910.1028; Bloodborne Pathogens, 29 CFR 1910.1030).
Paragraph (g)(6)(ii) requires the employer to assure that the
physician or other licensed health care professional, as appropriate,
evaluating an employee after an exposure incident receives: (A) A
description of the exposed employee's duties as they related to the
exposure incident; (B) a description of the circumstances under which
the exposure incident occurred; (C) the employee's diagnostic test
results, including drug susceptibility pattern, or other information
relating to the source of exposure that could assist in the medical
management of the employee; and (D) all of the employee's medical
records relevant to the medical evaluation of the employee, including
TB skin test results. Since the individual responsible for medical
surveillance may not necessarily be the person evaluating an employee
after an exposure incident, it is necessary to also provide a copy of
this standard to the evaluating physician or other appropriate licensed
health care professional, as required by paragraph (g)(6)(i). In this
way, the evaluator will also be informed of and implement the
standard's requirements. All of the above information is essential to
follow-up evaluation, and helps assure that an accurate determination
can be made regarding appropriate medical treatment of the exposed
employee. This provision is consistent with other OSHA standards (e.g.,
Bloodborne Pathogens, 29 CFR 1910.1030, Benzene, 29 CFR 1910.1028).
(7) Written Opinion
Paragraph (g)(7)(i) states that the employer shall obtain and
provide the employee with a copy of the written opinion of the
physician or other licensed health care professional, as appropriate,
within 15 days of the completion of all medical evaluations required by
this section. The purpose of requiring the employer to obtain a written
opinion is to assure that the employer is provided with documentation
that the medical evaluation of the employee (1) has taken place and
that the employee has been informed of the results; (2) has included an
evaluation of the employee's need for medical removal or work
restriction; (3) describes the employee's TB skin test status so that
the employer can assess action needed to prevent further exposure; and
(4) informs the employer of the employee's infectivity status so that
the employer can take action to prevent the employee from becoming a
source of infection for other employees.
The employer has a right to know the information contained in the
written opinion and may retain the original written opinion, but must
provide a copy to the employee. The 15 day provision assures that the
employee is informed in a timely manner regarding information received
by the employer and is consistent with other OSHA standards (e.g.,
Formaldehyde, 29 CFR 1910.1048; Benzene, 29 CFR 1910.1028; Bloodborne
Pathogens, 29 CFR 1910.1030).
In addition, the written opinion is required to assure the employer
that the employee has been provided with information about any medical
conditions resulting from exposure to tuberculosis which require
further evaluation or treatment.
OSHA believes it is important that employers know if their
employees have had evaluations for tuberculosis infection or exposure
incidents, and that physicians or other appropriate licensed health
care professionals, acting as agents for the employer, have provided
the employer with written documentation that these evaluations
occurred. However, paragraph (g)(7)(ii) limits the information the
employer is provided in order to protect the privacy of the employee.
The requirement for a written opinion after a medical evaluation has
been included in other OSHA standards (e.g., Occupational Exposures to
Hazardous Chemicals in Laboratories, 29 CFR 1910.1450; Formaldehyde, 29
CFR 1910.1048; Bloodborne Pathogens, 29 CFR 1910.1030).
Paragraph (g)(7)(ii)(E) requires the written opinion to state any
recommendations for medical removal or work restrictions and the
employee's ability to wear a respirator. This recommendation must be in
accordance with paragraphs (g)(5)(i) and (f)(5)(viii) of this section.
Including this information in the written opinion assures that the
employer is provided with written documentation of the need for removal
of an employee with infectious tuberculosis from the workplace. The
provision also assures that the employer is aware of any work
restrictions on the employee and the employee's ability or inability to
wear a respirator. This information enables the employer to take
appropriate steps in managing the employee's duties upon return to the
workplace. OSHA recognizes the need for this provision and has included
it in other standards (e.g., Lead in Construction, 29 CFR 1926.62).
Paragraph (g)(7)(iii) states that all other findings or diagnoses
shall remain confidential and shall not be included in the written
report. OSHA believes that all health care professionals have an
obligation to view medical information gathered or learned during
tuberculosis medical surveillance or post-exposure evaluation as
confidential medical information. As stated previously, the maintenance
of confidentiality encourages participation in medical surveillance by
allaying employee concern that medical conditions unrelated to
tuberculosis exposure will be communicated to the employer. OSHA also
recognizes that successful medical surveillance and medical management
and follow-up programs must guarantee this confidentiality, the
specific requirements on confidentiality can be found in applicable
state and federal laws and regulations that cover medical privacy and
confidentiality. Finally, OSHA recognizes the need for this provision
and has included it in other standards (e.g., Bloodborne Pathogens, 29
CFR 1910.1030).
Paragraph (h) Communication of Hazards and Training
Paragraph (h), Communication of Hazards and Training, addresses the
issues of transmitting information to employees about the hazards of
tuberculosis through the use of labels, signs, and information and
training. These provisions apply to all operations that come under the
coverage of
[[Page 54272]]
paragraph (a), Scope, of this section. Although OSHA has an existing
standard, Hazard Communication (29 CFR 1910.1200), which requires an
employer to inform employees about the hazards of chemical substances
they are exposed to occupationally, that standard does not apply to
biological hazards such as TB. Consequently, it is OSHA's intent in
this paragraph to assure that employees will receive adequate warning
through labels, signs, and training so that the employee understands
the hazard and can take steps to eliminate or minimize his or her
exposure to tuberculosis.
Paragraphs (h)(1) and (h)(2) of the proposed standard for
tuberculosis provide the specific labeling and sign requirements that
are to be used to warn employees of hazards to which they are exposed.
The requirements for labels and signs are consistent with section
6(b)(7) of the OSH Act, which prescribes the use of labels or other
appropriate forms of warning to apprise employees of occupational
hazards. As noted in paragraphs (c)(2)(v), (d)(3), and (d)(5) above,
settings where home health care and home-based hospice care are
provided are not required to have engineering controls and, therefore,
the signs and labeling would not be required in these cases.
Labels
Paragraph (h)(1)(i) requires that air systems that may reasonably
be anticipated to contain aerosolized M. tuberculosis must be labeled
at all points where ducts are accessed prior to a HEPA filter and at
duct access points, fans, and discharge outlets of non-HEPA filtered
direct discharge systems. The label must state ``Contaminated Air--
Respiratory Protection Required.'' The provision for labeling of air
ducts that may reasonably be anticipated to contain aerosolized M.
tuberculosis, with the proposed hazard warning, is supported by the CDC
in its discussion of HEPA filter systems. This discussion states:
Appropriate respiratory protection should be worn while
performing maintenance and testing procedures. In addition, filter
housing and ducts leading to the housing should be labeled clearly
with the words ``Contaminated Air'' (or a similar warning). (Ex. 4B)
The intent of this provision is to assure that employees who may be
accessing these systems for the purposes of activities such as
maintenance, replacement of filters, and connection of additional
ductwork are warned of the presence of air that may contain aerosolized
M. tuberculosis so that appropriate precautions can be taken.
Consequently, labels are to be placed at all points where these systems
are accessed.
In situations where air that may reasonably be anticipated to
contain aerosolized M. tuberculosis is discharged directly to the
outside, the exhaust outlets are also to be labeled. This is especially
important since these outlets will most likely be at a remote location
from the contaminated air source. Employees working in these locations
would have no warning of the hazard if these ducts were not labeled. In
addition, a number of exhaust outlets from a variety of sources may be
present in an area (e.g., a hospital roof). In such situations,
labeling also serves to distinguish contaminated air exhaust outlets
from others in the vicinity.
The proposed provision does not require that a symbol (e.g.,
``STOP'' sign) be included on the duct labels. OSHA believes that, in
many situations, the label will be stenciled onto the duct, similar to
the labeling used on other piping and duct labels currently being
employed in some of these facilities. In addition, the group of workers
accessing ducts will likely be a well-defined, skilled group that can
be trained to recognize the text's warning. However, OSHA seeks comment
on whether a symbol on duct labels is necessary and any information
regarding the current use of such symbols.
Paragraph (h)(1)(ii) requires that clinical and research laboratory
wastes that are contaminated with M. tuberculosis and are to be
decontaminated outside of the immediate laboratory must be labeled with
the biohazard symbol or placed in a red container(s). This provision is
intended to assure that employees are adequately warned that these
containers require special handling. In addition, the label or color-
coding serves as notice that certain precautions may be necessary
should materials in the container be released (e.g., a spill). This
provision closely follows the recommendations outlined in the CDC-NIH
publication ``Biosafety in Microbiological and Biomedical
Laboratories'' (Ex. 7-72) and is in accordance with the labeling
requirements of paragraph (e)(2)(i)(D), Clinical and Research
Laboratories, of this section.
Signs
Paragraph (h)(2) contains the provisions relative to the posting of
warning signs in areas where employees may be exposed to droplet nuclei
or other aerosols of M. tuberculosis. More specifically, paragraph
(h)(2)(i)(A) requires that signs be posted at the entrances to rooms or
areas used to isolate an individual with suspected or confirmed
infectious TB. The term ``rooms or areas'' is used in order to expand
the requirement beyond the AFB isolation room or area. Throughout the
course of a day various employees may enter such rooms or areas in
order to carry out their duties. These employees can include
physicians, nurses, respiratory therapists, housekeepers, and dietary
workers. Posting a sign at the entrance of those rooms or areas where
an individual with suspected or confirmed infectious TB is isolated
serves to warn employees that entry into the room or area requires that
certain precautions be taken. In addition, the employer may have
implemented a program to minimize the number of employees who enter
such rooms or areas. In this case, the sign serves as notice that entry
may not be permitted for a particular employee or group of employees.
As an additional public health benefit, such signs will also provide
warning to visitors or family members who may be entering the area and
are unaware of the hazard.
Paragraph (h)(2)(i)(B) requires that signs be posted at the
entrances to areas where procedures or services are being performed on
an individual with suspected or confirmed infectious TB. Although it is
critically important to provide appropriate warning to employees who
may inadvertently enter an isolation room, other areas of the facility
are of concern as well. Special treatment areas, such as bronchoscopy
suites, respiratory therapy areas where cough-inducing procedures are
performed, or radiology examination rooms may, at one time or another,
be occupied by an individual with suspected or confirmed infectious TB.
When individuals with suspected or confirmed tuberculosis are occupying
these areas, the area must have signs placed at the entrances in order
to warn employees of the hazard.
The risk of exposure to aerosolized M. tuberculosis also exists in
clinical and research laboratories where specimens, cultures, and
stocks containing the bacilli are present. Therefore, paragraph
(h)(2)(i)(C) requires that a sign be posted at the entrance to
laboratories where M. tuberculosis is present. Posting of such a sign
is consistent with the recommendations of the CDC/NIH publication
``Biosafety in Microbiological and Biomedical Laboratories'' (Ex. 7-72)
and is in accordance with the sign posting requirement of paragraph
(e)(2)(ii)(E), Clinical and Research Laboratories, of this section.
[[Page 54273]]
Even though a suspected or confirmed infectious individual is no
longer present in a room or area, the droplet nuclei generated by that
individual may continue to drift in the air. Consequently, the air in
the room or area presents a risk of TB infection until the droplet
nuclei are removed. With this in mind, paragraph (h)(2)(ii) requires
that when an AFB isolation room or area is vacated by an individual
with suspected or confirmed infectious TB, unless the individual has
been medically determined to be noninfectious, the sign shall remain
posted at the entrance until the room or area has been ventilated
according to CDC recommendations for a removal efficiency of 99.9%, to
prevent entry without the use of respiratory protection [The rationale
for specifying this removal efficiency has been discussed previously
under paragraph (d), Work Practices and Engineering Controls]. This
provision is supported by the CDC's current recommendations for
tuberculosis control (Ex. 4B).
The CDC has published guidelines regarding the length of time for
such sanitation of the room air based upon the air exchanges per hour
(see Appendix C of this section). Requiring that the sign remain posted
until the room or area is adequately ventilated will assure that
unprotected employees do not inadvertently enter while an infection
risk is still present.
Until such time as the room or area has been adequately ventilated,
employees entering the area must wear respiratory protection. This
paragraph is designed to address the situations where employees will be
entering or using a room or area previously occupied by an individual
with suspected or confirmed infectious TB before the room or area has
been satisfactorily ventilated. For example, when an infectious
tuberculosis patient is discharged from a facility and the room is
needed for an incoming new patient, certain housekeeping and
maintenance functions need to be done between patient occupancies.
Employees who must perform the tasks required to prepare the room for
the next patient must wear respiratory protection until such time as
the room has been adequately ventilated, based upon the CDC criteria.
Obviously, if the room was previously occupied by an individual with
suspected infectious TB and that individual is medically determined to
be noninfectious, it would not be necessary to ventilate the room to
remove M. tuberculosis nor to continue to post a sign at the entrance
to the room since there would be no tuberculosis bacilli present.
OSHA has given much consideration to what sign should be required
for posting outside of isolation rooms or areas and for areas where
procedures or services are performed on individuals with suspected or
confirmed infectious TB. The purpose of the sign is to convey a uniform
warning along with the necessary precautions to be used for the
particular situation.
The sign recommended by the CDC in 1983 in their ``CDC Guidelines
for Isolation Precautions in Hospitals'' (Ex. 7-112) read ``AFB
Isolation'' and then listed the requirements for entry. However, the
instructions on the CDC sign are different from OSHA's requirements.
For example, the sign instructed workers that ``Masks are indicated
only when patient is coughing and does not reliably cover mouth'', a
recommendation that is currently outdated and no longer recommended by
CDC. The document contained another sign for ``Respiratory Isolation''
but this sign was designed for use with a number of respiratory hazards
(rubella, meningococcal meningitis, chickenpox) that are not addressed
in OSHA's proposed standard. Neither the 1990 CDC tuberculosis
guidelines (Ex. 3-32) nor the 1994 CDC tuberculosis guidelines (Ex. 4B)
provided help with this issue. OSHA also considered using a sign having
the words ``AFB Isolation'' however, there is some concern that ``AFB
Isolation'' could compromise patient confidentiality. For example, that
sign outside of a treatment area or isolation room would allow members
of the public or employees with no ``need to know'' to discern the
potential diagnosis of the individual being isolated.
In addition, OSHA was unable to find uniform recommendations about
signs in sources outside of the CDC. A number of facilities use signs
to warn employees of the hazard of TB, but these signs vary widely and
often had been developed for a particular facility. Thus, facilities
that were using TB warning signs did not appear to be universally
applying a specific sign.
The Agency does not believe, however, that development of a sign
should be left to individual employers since this could lead to a
variety of signs that may not provide adequate warning of the hazard.
In the work settings covered by the proposal, there are many employees
who move from facility to facility or even from industry to industry.
In fact, a substantial number, like contract nurses, will work in
several facilities at one time. A universal sign will enable these
employees to recognize the hazard wherever it occurs and then take
proper precautions. The issue of whether OSHA should specify colors
that must be included on the sign was raised at TB stakeholder
meetings. OSHA realizes there is a part of the population, perhaps as
high as 10% of all men, that is color blind and that at some work sites
some colors have been employed that are different from the red that
OSHA proposes be used. However, stakeholders, particularly those whose
jobs took them to several different work sites, urged OSHA to require a
standardized sign and, of those who considered the issue, there was
general agreement that the red on the familiar ``stop'' sign was
appropriate. OSHA has preliminarily concluded that the colors required
provide needed warning even though not all employees (e.g., those who
are color blind) may benefit from them, and that the colors chosen are
consistent with conventions on health signage. The Agency has developed
a sign that it believes will provide appropriate warning and be easily
recognizable. Failing to find either a guideline recommendation or a
generally accepted community standard regarding what sign should be
placed at the entrances to these areas, OSHA looked to generic, broad-
based sources for symbols which would be easily identifiable,
understandable to workers who were not able to read well or are non-
English speaking, and simple to construct.
In paragraph (h)(2)(iii), therefore, OSHA is proposing that a
``STOP'' sign with the accompanying legend, ``No Admittance Without
Wearing A Type N95 Or More Protective Respirator'', meets these
criteria. The sign is easily recognizable, requires a simple color
scheme, and should be understandable to employees with minimal
training.
OSHA is seeking information on the effectiveness of the proposed
sign to warn workers of the presence of a hazard, as well as
information on other signs that may be more effective. Please be
specific when providing information, keeping in mind the wide variety
of work sites where signs will be needed. Where an alternative is being
proposed, please enclose a model or drawing as well as the rationale
for believing that it will be more effective than OSHA's proposed sign.
Paragraph (h)(2)(iv) requires that signs at the entrances of
clinical or research laboratories and autopsy suites where procedures
are being performed that may generate aerosolized M. tuberculosis
include the biohazard symbol, name and telephone number of the
laboratory director or other designated responsible person, the
infectious agent designation
[[Page 54274]]
``Mycobacterium tuberculosis'', and special requirements for entering
the laboratory or autopsy suite. This provision has been taken directly
from the CDC/NIH publication ``Biosafety in Microbiological and
Biomedical Laboratories'' (Ex. 7-72). As previously discussed, the
purpose for this sign is to warn employees of the potential TB hazard
and inform them of precautions that must be taken to prevent exposure.
Information and Training
It is OSHA's position that employees must understand the nature of
the hazards in their workplace and the procedures to follow in order to
eliminate or minimize their risks of exposure to these hazards. (Exs.
4-B, 7-169, 7-170, 7-61, 7-64) In the case of M. tuberculosis, employee
exposures may result in a TB infection, which may ultimately result in
disease and even death. The provisions in paragraph (h)(3) of this
proposed standard set forth the training that each employer must
provide to his or her employees. OSHA believes that effective training
is a critical element in any occupational safety and health program. In
this proposed standard, the employer would be required to provide
training for each employee covered by the scope of the standard.
Paragraph (h)(3)(i) requires that employers assure that each
employee with occupational exposure participates in training, which
must be provided at no cost to the employee and be made available at a
reasonable time and place. Since appropriate training is considered to
be critical in assuring employee protection, the employer is
responsible for making sure that each employee with occupational
exposure participates in the training program. Having the employee pay
in some manner for all or part of the training or requiring the
employee to attend training at an unreasonable time and place would be
a disincentive to participation. If training cannot feasibly be
provided during work hours, employees are to be paid for training
scheduled outside of normal working hours.
In view of the importance of training, OSHA is proposing that it be
provided at several particular points in time. (Exs. 7-169; 4-B) More
specifically, paragraph (h)(3)(ii) requires that training be provided:
(A) before initial assignment to tasks where occupational exposure may
occur, for those employees without previous occupational exposure; (B)
within 60 days after the effective date of the final standard, for
those employees who have occupational exposure at the time of the
standard's promulgation; and (C) at least annually thereafter, unless
the employer can demonstrate that the employee has the specific
knowledge and skills required under paragraph (h)(3)(vii). The employer
must provide re-training to an employee in any of the topic(s) in
paragraph (h)(3)(vii) in which that employee cannot demonstrate the
necessary knowledge and/or skill. This approach to training frequency
assures that employees entering jobs with occupational exposure will be
fully trained before exposure occurs. In addition, employees who are
already working in jobs with occupational exposure at the time of the
standard's promulgation will receive training and must become
knowledgeable in all of the required aspects of the standard (e.g.,
employer's exposure control plan, medical surveillance program, warning
signs and labels) within a short period of time.
Annual re-training reinforces the initial training and provides an
opportunity to present new information that was not available at the
time of initial training. The Agency recognizes that, as a result of
training previously provided by the employer, employees may possess
some of the knowledge and skills listed in the training topics in
paragraph (h)(3)(vii). Consequently, OSHA is proposing that re-training
be provided annually unless the employer can demonstrate that the
employee has the specific knowledge and skills required by this
paragraph. The employer must provide re-training to an employee in any
topic(s) in paragraph (h)(3)(vii) in which the employee cannot
demonstrate specific knowledge and skills.
An employee with occupational exposure to TB who moves to a job
with another employer that also involves occupational exposure to TB
would not need to meet all of the initial training requirements. In
such instances, the Agency has determined that the employee's prior
training in the general topics required by the standard (e.g., the
general epidemiology of tuberculosis, the difference between
tuberculosis infection and tuberculosis disease) would remain relevant
in the new work setting and that the new employer need not re-train in
these topics. However, the employee would not possess knowledge of the
topics required by the standard that are specific to the new employer's
particular work setting (e.g., the new employer's exposure control plan
and respiratory protection program and the means by which the employee
could access the written plans for review). OSHA is proposing to permit
limited ``portability'' of training, as noted in the standard. This
note states that training in the general topics listed in paragraph
(h)(3)(vii) that has been provided in the past 12 months by a previous
employer may be transferred to an employee's new employer. However, the
new employer must provide training in the site-specific topics listed
in paragraph (h)(3)(vii) in accordance with the requirements of
paragraph (h) (e.g., at no cost to the employee and at a reasonable
time and place).
OSHA is aware that some employers have already established training
for their occupationally exposed employees. (Ex. 7-169) In light of
this, paragraph (h)(3)(iii) of the proposed standard requires only that
limited training be conducted for those employees who already have
received training on tuberculosis in the year preceding the effective
date of the standard. The additional training would only have to
address those provisions of the standard not previously covered in the
earlier training.
The requirement for annual training within one year of the
employee's previous training, in paragraph (h)(3)(iv), assures that
each employee receives training within 12 calendar months of his or her
last training. Annual training is not based on a calendar year; that
is, training will not be permitted to be provided to an employee in
January of one year and in December of the following year, essentially
a 23-month span between training sessions. Employers may establish
schedules for training around this requirement.
Also, paragraph (h)(3)(v) stipulates that the employer must provide
additional training whenever changes in the occupational environment,
such as modification of tasks or procedures or institution of new tasks
or procedures, affect the employee's occupational exposure to M.
tuberculosis. This provision will assure that employees remain apprised
of any new exposure hazards and the precautions necessary to protect
themselves from exposure. This additional training does not need to
entail a complete reiteration of the annual training, but may be
limited to addressing the new sources of potential exposure.
The proposed standard requires that training material be used that
is appropriate in content and vocabulary to the educational level,
literacy and language of employees. Employees must be able to
comprehend the information being conveyed in order for it to be useful.
Therefore, the employer has the responsibility for assuring that the
training is provided in an understandable manner to the audience being
addressed. This provision would
[[Page 54275]]
assure that employees, regardless of their educational or cultural
background, will receive adequate training.
Paragraph (h)(3)(vii) of the proposed standard contains the
specific elements that would comprise a minimum training program. (Exs.
4-B; 7-169; 7-64) The provisions for employee training are performance
oriented, stating the categories of information to be transmitted to
employees and not the specific ways that this is to be accomplished.
This assures that important information is communicated to employees
about the nature of this occupational hazard while allowing employers
the most flexible approach to providing training. OSHA has set forth
the objectives to be met and the intent of training. The specifics of
how the employer assures that employees are made aware of the hazards
in their workplace and how they can help to protect themselves are left
up to the employer who is best qualified to tailor the training to the
TB hazards in his or her workplace.
The proposed standard would require the employer to explain a
number of particular topics in the training session(s). Paragraph
(h)(3)(vii)(A) requires the employer to provide an explanation of the
contents of this standard and the location of an accessible copy of the
regulatory text and appendices to this standard. This enables the
employee to have access to the standard and to become familiar with its
provisions. It is not necessary for the employer to provide each
employee with a copy of the standard; it is sufficient for the employer
simply to make a copy accessible. For example, a copy of the standard
could be posted in a location where it could be readily and easily
viewed by employees.
An important element in the training involves an overview of the
epidemiology of tuberculosis, the pathogenesis of the disease and an
explanation of various aspects of risk to employees. (Ex. 4B) More
specifically, paragraph (h)(3)(vii)(B) requires that the training
include an explanation of: the general epidemiology of tuberculosis,
including multidrug-resistant TB and the potential for exposure in the
facility; the signs and symptoms of TB, including the difference
between TB infection and TB disease; the modes of transmission of
tuberculosis, including the possibility of reinfection in persons with
a positive tuberculin skin test; and the personal health conditions
that increase an employee's risk of developing TB disease if infected.
Since the employer can tailor the training to the needs of his or
her employees, the training program will likely be more technical for
some audiences and less technical for others. The general goal of this
paragraph is to assure that each employee being trained understands
what tuberculosis is, how it is spread, and possible risks that may
affect the employee.
Employees need to be able to recognize symptoms associated with TB
disease. (Ex. 4B) The employee must understand that certain symptoms
(e.g., a persistent cough lasting 3 or more weeks, bloody sputum, night
sweats, anorexia, weight loss, fever) may be related to TB. In
addition, information on non-occupational risk factors that place
employees at increased risk of developing tuberculosis disease
following an infection permits those individuals at increased risk to
make informed decisions about their employment situations.
Paragraph (h)(3)(vii)(C) requires an explanation of the employer's
exposure control plan and respiratory protection program. Employees
must also be informed about what steps they need to take to review the
written plans, if they so desire.
Paragraph (h)(3)(vii)(D) requires the employer to train employees
regarding the tasks and other activities that may involve occupational
exposure to tuberculosis. Employees must be made aware of those job
duties which may expose them to tuberculosis. For example, although
certain health care professionals may easily recognize the hazard
involved in transporting a person with infectious TB, the staff of a
correctional facility may not. On the other hand, some health care
professionals may not immediately recognize that their mere presence in
a room where an individual with suspected or confirmed infectious TB is
being X-rayed presents an exposure risk and necessitates wearing a
respirator. All occupationally exposed employees need training that
will enable them to recognize those activities that put them at risk of
exposure.
Paragraph (h)(3)(vii)(E) of this section requires employers to
train employees regarding both the uses and limitations of various
control measures, specifically those used at the employees' worksite.
Exposed employees must be familiar with the employer's tuberculosis
policies and procedures in order for them to be properly implemented.
Control of exposure frequently involves using a variety or combination
of engineering controls, administrative controls, work practice
procedures and personal protective equipment. To assure that employees
will be able to identify and implement methods of reducing occupational
exposure to tuberculosis, they must understand how these controls are
applied in their work sites and the limitations thereof. With this
understanding, employees will be more likely to use the appropriate
control for the situation at hand and to use it correctly. For example,
employees must be able to recognize the labels and signs used to
identify rooms or areas where suspected or confirmed infectious
individuals are present so that they can take appropriate precautions
before entering. Understanding of the limitations of control measures
will also enable employees to recognize when inappropriate or
inadequate control measures have been taken and increases the
likelihood that they will report such situations.
Training must be relevant to the specific site where the employee
will be working. Each employee must know, for example, the procedures
used in his or her particular facility to identify suspected infectious
TB cases, where respiratory protection is kept, and what engineering
controls are in place within the facility. This training is
particularly important for workers who move between several facilities
in the course of their work, for example, ``leased'' personnel, part-
time employees, ``moonlighters'', or contractors.
The provision covering the selection, types, proper use, location,
removal and handling of respiratory protection, paragraph
(h)(3)(vii)(F), is particularly important because many of the employees
and employers proposed to be covered by the tuberculosis standard may
not be accustomed to the use, selection, and upkeep of respiratory
protection. Consequently, training on aspects such as the necessity for
respiratory protection, the appropriate type of respiratory protection,
where to obtain it, and its proper use, fit, and the general upkeep is
necessary to assure the effectiveness of respirator use. (Ex. 7-64)
OSHA believes that employees who have a clear understanding of the
medical surveillance program (its purpose, methodology, and the
significance of the results of examinations and tests), will be much
more likely to participate in that program. Therefore, paragraph
(h)(3)(vii)(G) requires that the training include an explanation of the
employer's medical surveillance program, including the purpose of
tuberculin skin testing, the importance of a positive or negative skin
test result, anergy testing, and the importance of participation in the
program. This increased participation by trained
[[Page 54276]]
employees helps the employee to identify changes in his or her personal
health status and also aids the employer in assessing the effectiveness
of his or her TB control program.
Each employee must understand the actions to be taken if an
occupational exposure occurs as well as what is available to them
regarding appropriate medical treatment, prophylaxis, and post exposure
follow-up in order for the employee to lessen the chance of developing
active disease. Therefore, paragraph (h)(3)(vii)(H) would require an
explanation of the procedures to follow if an exposure incident occurs,
including the method of reporting the incident, an explanation of the
medical management and follow-up that the employer is required to
provide, and the benefits and risks of drug prophylaxis. In addition,
the employee must be provided with an explanation of the procedures to
follow if the employee develops signs or symptoms of tuberculosis
disease [paragraph (h)(3)(vii)(I)]. In this way, an employee who notes
the signs or symptoms of personal disease development will be aware of
the appropriate steps to take, thereby speeding initiation of medical
evaluation. Quick evaluation protects the employee, co-workers, and the
public.
In paragraph (h)(3)(viii), the proposed standard mandates that the
person conducting the training must be knowledgeable in the subject
matter as it relates to the specific workplace being addressed. OSHA
believes that a variety of persons are capable of providing effective
training to employees. OSHA has approached this section of the proposed
standard in much the same way as the trainer requirements were
addressed in the standard for Occupational Exposure to Bloodborne
Pathogens. That is, a knowledgeable trainer is one who is able to
demonstrate expertise in the area of the occupational hazard of
tuberculosis and is familiar with the manner in which the elements of
the training program relate to the particular workplace.
A number of resources are available through the Centers for Disease
Control and Prevention and professional organizations such as the
American Lung Association and the American Thoracic Society that can be
used to educate trainers and prepare them for this task. In addition,
specialized training courses in the area of tuberculosis control can
also assist in educating trainers (Ex. 7-189).
In addition to general knowledge of the subject matter, it is
important that the trainer be able to instruct the participants in
site-specific features of the Exposure Control Plan that will reduce
their risk in the particular facility. This benefits not only employees
within the facility but also provides temporary employees with the
information needed to protect themselves against exposure while working
in the facility. For example, workers who have received general
training by their employer (e.g., a personnel staffing agency) will
also receive training about the facility where they will actually
perform their duties (e.g., a specific hospital).
An important component of an effective learning experience is the
opportunity for the learner to interact with the trainer for the
purposes of asking questions and obtaining clarification. Paragraph
(h)(3)(ix) would require that the employer provide employees with this
opportunity as part of the training program. The trainer must be
available at the time that the training takes place. OSHA would expect
that in most instances, the individual who would provide answers to the
employee's question would be physically present when the employee is
trained. The Agency does recognize, however, that there may be some
instances where this is not possible. In these cases, it would be
acceptable for the employee to ask questions by telephone.
An employer would not be expected to train employees in site-
specific topics that are not applicable to the employer's work setting.
For example, if a facility was not required by the standard to utilize
engineering controls, the employer would not be responsible for
training his or her employees about the various aspects of engineering
controls.
OSHA believes that the information and training requirements
incorporated into this proposed standard are needed to inform employees
about the hazard of tuberculosis and to provide employees with an
understanding of the degree to which they can minimize the health
hazard. Training is essential to an effective overall hazard
communication program and serves to explain and reinforce the
information presented to employees on signs and labels. These forms of
information and warning will be meaningful only when employees
understand the information presented and are aware of the actions to be
taken to avoid or minimize exposure.
OSHA seeks comment on the proposed content of the training program
and requests that model TB training programs be submitted to the
docket, particularly those designed for audiences whose participants
may have language difficulties or have no health care background, and
those that have been judged to be successful in communicating
information to employees. It is OSHA's intent, upon publication of the
final standard, to include information on training programs in
compliance guides to be developed for small entities.
Paragraph (i) Recordkeeping
This proposed standard requires employers to keep records related
to TB, including medical surveillance and training records for all
employees with occupational exposure and engineering control
maintenance and monitoring records. OSHA has made a preliminary
determination that, in this context, medical and training records are
necessary to assure that employees receive appropriate information on
hazards and effective prevention and treatment measures, as well as to
aid in the general development of information on the occupational
transmission of TB. Specifically, OSHA believes that maintenance of
medical records is essential because documentation is necessary to
ensure proper evaluation of an employee's infection status and for
prompt and proper healthcare management following an exposure incident.
OSHA has also preliminarily determined that maintenance and monitoring
records for engineering controls are necessary for two reasons: to
enable the employer to know that the control methods remain in good
working order so as to assure their effectiveness and to aid the Agency
in enforcement of the standard.
In paragraph (i)(1), OSHA proposes to require employers to
establish and maintain a medical record in accordance with 29 CFR
1910.1020 for each employee with occupational exposure to TB. The
record must include: (A) The name, social security number, and job
classification of the employee; (B) A copy of all results of
examinations, medical testing, including the employee's tuberculin skin
test status; and follow-up procedures required by paragraph (g); (C)
The employer's copy of the physician's or other licensed health care
professional's written opinion as required by paragraph (g)(7); and (D)
A copy of the information provided to the physician or other health
care professional required by paragraph (g)(6). The information that
must be included in the medical record is necessary for the proper
evaluation of the employee's infection status and management of
occupational exposure incidents. This record will aid OSHA in enforcing
the standard and the information therein, when analyzed, will further
the development of health
[[Page 54277]]
data on the causes and prevention of occupational transmission of TB.
Similar provisions for collection and retention of such information
have been included in other OSHA health standards including, most
recently, Bloodborne Pathogens (29 CFR 1910.1030) and Cadmium (29 CFR
1910.1027).
In paragraph (i)(1)(iii), OSHA is proposing to require that the
employee medical records be kept confidential and not be disclosed or
reported to anyone without the employee's express written consent
except as required by section i or as may be required by law. In nearly
every health standard rulemaking, employees have told the Agency that
keeping medical records confidential is extremely important to them.
Employees stated that, without assurance of confidentiality, they would
be reluctant to participate in medical surveillance, a predicament that
would be detrimental to their health and could affect health and safety
conditions in the workplace. During the Bloodborne Pathogens
rulemaking, confidentiality of medical records was a major issue due to
the nature of the diseases addressed. Of particular concern was keeping
the medical records from being disclosed to the employer. It was
explained in the Bloodborne Pathogens standard and is applicable here
that such confidentiality can be accomplished by having the records
kept by the physician or other licensed health care provider at the
expense of the employer. In those cases where the employer is the
health care provider, the records can be maintained separately from
other employee records so that disclosure can be strictly limited to
the physician or other licensed health care professional and his or her
staff who are responsible for the medical management of the employee.
It was pointed out in the preamble to the Bloodborne Pathogens
standard, and bears repeating here, that the confidentiality provisions
in the proposed standard are reiterations of existing standards of
conduct in the health care professions and that the OSHA requirements
do not abridge, enlarge or alter existing ethical or statutory codes
(56 FR 64170). This section of the proposal requires that medical
records be disclosed to the Assistant Secretary or the Director (of
NIOSH) and as may be required by law, which means that this proposed
standard would not prevent employers from reporting TB cases to
federal, state, or municipal health departments where that reporting is
required by law.
Paragraph (i)(1)(iv) proposes to require that medical records be
maintained in accordance with 29 CFR 1910.1020 for at least the
duration of employment plus 30 years. The Access to Medical Records
Standard contains an exception to the 30-year requirement that provides
that the medical records of an employee who has worked less than one
year must be maintained throughout his or her employment, but need not
be retained afterwards as long as they are given to the employee upon
termination of employment. Maintaining the records for the duration of
employment serves several purposes: the records can provide valuable
information to the employee's healthcare provider; the records enable
the employer to know that employees are benefitting from regular
surveillance and timely intervention following occupational exposure to
TB; analysis and aggregation of the records can provide insight into
the causes and consequences of occupational exposure to TB; and, the
records will aid in the enforcement of the standard. Requiring the
records to be kept 30 years beyond employment is necessary because TB
can have a long incubation period, with disease often appearing only
many years after initial infection. This retention time is also
consistent with other OSHA health standards (See for example Benzene,
29 CFR 1910.1028; Bloodborne Pathogens, 29 CFR 1910.1030; Ethylene
Oxide, 29 CFR 1910.1047).
In paragraph (i)(2), OSHA proposes to require employers to record
TB infection and disease in accordance with 29 CFR 1904, Recording and
Reporting Occupational Injuries and Illnesses, and 29 CFR 1960, the
equivalent requirement for Federal Agency programs. This should not be
an unfamiliar requirement to employers because occupational TB
infections and disease must be reported in accordance with 29 CFR 1904
and 29 CFR 1960, as directed by current OSHA enforcement policy (Ex. 7-
1).
In paragraph (i)(3), OSHA proposes to require training records,
which include: (A) The dates of the training sessions; (B) The contents
or a summary of the training sessions; (C) The names and qualifications
of persons conducting the training; and (D) The name and job
classification of all persons attending the training sessions. This
requirement is consistent with other OSHA standards, particularly
Bloodborne Pathogens, and it represents the minimum amount of
information an employer, an employee, or an OSHA compliance officer
would need in order to determine when and what training had been
provided, who administered it and who attended. Additionally, such a
record is an invaluable aid to the employer when evaluating his or her
training program.
OSHA proposes, in paragraph (i)(3)(ii) to require that training
records be maintained for three years beyond the date the training
occurred. The Agency anticipates that employers will not have
difficulty maintaining the records for three years because the
information to be included is not extensive and many employers are
already keeping training records three years as required by other OSHA
standards (e.g., Bloodborne Pathogens, 29 CFR 1910.1030). Moreover,
these records are not required to be kept confidential and so may
become part of an employee's personnel file or part of a larger file,
at the discretion of the employer.
In paragraph (i)(4), OSHA proposes to require engineering control
maintenance and monitoring records be kept that include: (A) Date; (B)
Equipment identification; (C) Task performed; and (D) Sign-off. The
performance monitoring records must include: (A) Date and time; (B)
Location; (C) Parameter measured; (D) Results of Monitoring; and (E)
Sign-off. Only two of these items will require more than a few words or
numbers to record; the two items that require more extensive
information are the maintenance task performed and the results of the
performance monitoring. Where the employer has not already developed a
method for recording the task performed, the maintenance person can
list the tasks or use a previously prepared check-list. The results of
performance monitoring can be recorded in the same way or another way
that meets the needs of the particular workplace so long as it includes
all of the information required by the paragraph. OSHA believes that
the information in these records is the usual data that are generated
by persons maintaining and servicing equipment so that the status of
the equipment and its effectiveness can be known for a given time. The
information is also useful in determining when further servicing is
needed.
Proposed paragraph (i)(4)(iii) requires engineering control
maintenance and monitoring records to be maintained for three years.
The three year period is a reasonable period of time and it will enable
the employer to develop and sustain a proper maintenance program and to
track the effectiveness of the controls. Moreover, the records will aid
the OSHA compliance officer in enforcing the standard's requirements
for engineering controls.
Availability of medical records is specified in section 8(c) of the
Act. In paragraph (i)(5) of this standard, OSHA
[[Page 54278]]
proposes to restrict the availability of employee medical records while
making employee training records and engineering control and monitoring
records generally available upon request. Medical records must be
provided to the subject employee, to anyone having written consent from
the employee, to the Director and to the Assistant Secretary in
accordance with 29 CFR 1910.1020, which sets forth the procedures that
will protect the privacy concerns of the employees. This paragraph does
not affect existing legal and ethical obligations concerning
maintenance and confidentiality of employee medical records. An
employer's access is governed by existing federal, state and local laws
and regulation. This standard, like Bloodborne Pathogens (29 CFR
1910.1030) and other OSHA standards, limits employer access to
confidential information while allowing the employer access to the
information needed to make appropriate decisions relative to his or her
medical surveillance program. For example, paragraph (g)(7)(ii) limits
the information that can be included in the physician's or other
licensed health care professional's written opinion and paragraph
(g)(7)(iii) requires that other medical diagnoses or findings be kept
confidential. There is no language in this proposed standard that
grants an employer access to the confidential information in an
employee's medical file. OSHA illness and injury records are accessible
under 29 CFR 1904 and 29 CFR 1960, as appropriate, to the facility. In
this proposal, as in OSHA's other health standards, training records
and engineering control maintenance and monitoring records are to be
provided upon request to the employees, their representatives, the
Director and the Assistant Secretary. Employers should not have
difficulty complying with this provision because most will have
experience with such recordkeeping from other standards. There are no
confidentiality issues raised by these records.
In paragraph (i)(6), an employer who goes out of business is
required to transfer medical records as set forth in 29 CFR
1910.1020(h) and 29 CFR 1904, which address the transfer of medical
records. Specifically, medical records must be transferred to a
successor employer who must accept them and keep them in accordance
with the requirements of 29 CFR 1910.1020. In the event the employer
ceases to do business and there is no successor employer, the employer
is required to notify the Director, at least three months prior to
disposal of the records, and transmit them to the Director if required
by the Director to do so. This is consistent with other health
standards and ensures that a successor employer (and the employees) can
benefit from the information contained in the records. The reason the
records are transferred (if requested) to the Director of NIOSH is that
NIOSH has a vested interest in maintaining records of occupational
injuries and illnesses and is in an excellent position to decide how
the records can be best used to be of value to the exposed employee,
subsequent employees in the field and OSHA. At NIOSH, the records
remain confidential as required by 29 CFR 1910.1020(e). Thus, only the
employee or his or her representative with the permission of the
employee retains access to the medical records transferred to NIOSH.
Paragraph (j) Definitions
Acid-Fast Bacilli (AFB) means bacteria that retain certain dyes
after being washed in an acid solution. Most acid-fast organisms are
mycobacteria. Smears of sputum samples and other clinical specimens may
be stained with dyes to detect acid-fast mycobacteria such as M.
tuberculosis. However, AFB smear tests cannot distinguish one type of
mycobacteria from another. Therefore, as noted by CDC, when AFB are
seen on a stained smear of sputum or other clinical specimens, a
diagnosis of TB should be suspected; however, the diagnosis of TB is
not confirmed until a culture is grown and identified as M.
tuberculosis (Ex. 4B).
Accredited Laboratory for purposes of this standard means a
laboratory that has participated in a quality assurance program leading
to a certification of competence administered by a governmental or
private organization that tests and certifies laboratories. Under the
medical surveillance provisions of the proposed standard, paragraph
(g)(1)(iv) requires that all laboratory tests required by the standard
be conducted by an accredited laboratory. This definition makes clear
OSHA's intent about the type of laboratory that would be required to
conduct these types of tests.
The term AFB Isolation Room or Area refers specifically to the
rooms or areas where individuals with suspected or confirmed infectious
TB are isolated. For purposes of this standard this term includes, but
is not limited to, rooms, areas, booths, tents or other enclosures that
are maintained at negative pressure relative to adjacent areas in order
to control the spread of aerosolized M. tuberculosis. Such rooms or
areas are able to contain droplet nuclei through unidirectional airflow
into the room (i.e., negative pressure). A definition of negative
pressure is presented below and a more detailed explanation can be
found in the Summary and Explanation of paragraph (d), Work Practices
and Engineering Controls.
Air purifying respirator means a respirator that is designed to
remove air contaminants from the ambient air or air surrounding the
respirator. Air purifying respirators remove particular contaminants
(e.g., particulates, organic vapors, acid gases) from the ambient air
by drawing the air through appropriate filters, cartridges, of
canisters.
Anergy means the inability of a person to react to skin test
antigens (even if the person is infected with the organism(s)tested
because of immunosuppression. More specifically, an anergic
individual's immune system has become so compromised that it is unable
to mount a sufficient reaction to the test organism. Because of their
inability to respond immunologically, persons with anergy will have a
negative tuberculin skin test even if they are infected with M.
tuberculosis. Therefore, as noted by the CDC, it may be necessary to
consider other epidemiologic factors (e.g., the proportion of other
persons with the same level of exposure who have positive tuberculin
skin test results and the intensity or duration of exposure to
infectious TB patients that the anergic person experienced) when making
a determination as to whether that anergic individual has been infected
with M. tuberculosis (Ex. 4B). As discussed under paragraph
(g)(2)(iii), Medical Surveillance, tuberculin skin testing is to
include anergy testing when the physician or other licensed health care
professional, as appropriate, determines such testing is necessary.
Knowing which individuals are anergic will help to determine those
situations where information other than skin test status will need to
be ascertained and considered in order to assess the likelihood of
infection for exposed employees.
Assistant Secretary means the Assistant Secretary of Labor for
Occupational Safety and Health, or designated representative, and is a
definition consistent across all OSHA standards.
BCG (Bacille Calmette-Guerin) vaccine means a tuberculosis vaccine
used in many parts of the world. Because of its variable efficacy and
its impact upon tuberculin skin tests (i.e., making skin test
interpretation more difficult), routine BCG vaccination is not
currently recommended in the
[[Page 54279]]
United States (Ex. 7-50). However, many foreign countries still use BCG
as part of their tuberculosis control programs, especially for infants
(Ex. 7-72). Since individuals vaccinated with BCG may have a tuberculin
skin test that cannot be distinguished reliably from a reaction caused
by infection with M. tuberculosis, it is helpful to know whether an
individual has been vaccinated with BCG and when such vaccination
occurred. Thus, under the medical surveillance provisions of the
proposed standard, the medical history is to include a history of BCG
vaccination.
Cartridge or canister means a container with a filter, sorbent, or
catalyst, or a combination of these items, that removes specific air
contaminants from the air drawn through the container. With respect to
this standard, respirators would be equipped with cartridges or
canisters containing particulate filters.
Clinical laboratory has been defined for purposes of this standard
as a facility or an area of a facility that conducts routine and
repetitive operations for the diagnosis of TB, such as preparing acid-
fast smears and culturing sputa or other clinical specimens for
identification, typing or susceptibility testing. This definition is
meant to apply to laboratories where routine diagnostic tests for TB
are conducted as compared to research laboratories where M.
tuberculosis may be cultured in large volumes or concentrated for
research or commercial production. Clinical laboratories may be located
within facilities such as hospitals or clinics, or they may be
freestanding facilities.
Confirmed infectious tuberculosis (TB) means a disease state that
has been diagnosed by positive identification of M. tuberculosis from
body fluid or tissue through positive culture, positive gene probe, or
positive polymerase chain reaction (PCR); and the individual is capable
of transmitting the disease to another person. The disease state may be
manifested as pulmonary or laryngeal TB or extrapulmonary TB if the
infected tissue is exposed and could generate droplet nuclei.
As discussed under the definition for AFB, a positive AFB smear
indicates only that an individual has an identifiable mycobacterium.
The three methods listed here provide positive confirmation of M.
tuberculosis. In addition, the definition states that the disease state
must be capable of being transmitted to another person (i.e.,
infectious). This provision of the definition is to differentiate this
state of the disease from other active forms of TB disease where the
individual is not infectious. For example, an individual may contract
active TB disease and become infectious. After adequate drug therapy
has been initiated the individual may become noninfectious, at which
point he or she cannot transmit the disease to other individuals.
However, the individual, while no longer infectious, still has active
disease and must continue treatment for several months because living
bacilli are still in his or her body. The definition also states that
the disease may be manifested as pulmonary or laryngeal TB or
extrapulmonary TB if the infected tissue is exposed and could generate
droplet nuclei. In most cases, it is the pulmonary or laryngeal forms
of infectious TB that present a risk of infection for other
individuals. This is due to the fact that tuberculosis bacilli in the
pulmonary or laryngeal tracts may be easily dispelled when infectious
individuals cough or speak. Other body sites infected with the bacilli,
i.e., extrapulmonary TB, do not present an infection hazard in most
cases because the bacilli are not capable of being dispelled outside
the body. However, in some situations, such as a lesion or an abscess
where the infected tissue is exposed, there may be a risk of
transmission of disease when certain procedures are performed (e.g.,
tissue irrigation) that could generate droplet nuclei containing the
bacilli.
Conversion means a change in tuberculin skin test results from
negative to positive, based upon current Centers for Disease Control
and Prevention (CDC) guidelines. Under paragraph (g), the employer is
required to provide medical management and follow-up to employees who
have converted to positive tuberculin skin test status (e.g., providing
preventive therapy, if appropriate, and conducting follow-up
investigations of circumstances surrounding the conversion). Since a
number of specific actions are required of the employer as a result of
a conversion, it is necessary that conversions be correctly identified.
An important part of this identification is the interpretation as to
whether an employee has a positive skin test response. As such, this
definition states that the interpretation of the positive reaction
should be based upon current CDC guidelines (Ex. 4B). It is not OSHA's
intent to define what should constitute a positive reaction, but rather
to assure that such determinations are made using currently accepted
public health guidelines.
Director means the Director of the National Institute for
Occupational Safety and Health, U.S. Department of Health and Human
Services, or designated representative. Similar to the definition for
Assistant Secretary, the definition for Director is consistent across
OSHA standards.
Disposable respirator means a respiratory protective device that
cannot be resupplied with an unused filter or cartridge and that is to
be discarded in its entirety after its useful service life has been
reached. In general, the facepiece of these respirators is constructed
from the particular filter media of interest (e.g., particulate
filter).
Exposure incident for purposes of this standard means an event in
which an employee has been exposed to an individual with confirmed
infectious TB or to air containing aerosolized M. tuberculosis without
the benefit of all of the applicable exposure control measures required
by this section. This definition is limited to those situations
involving exposure to an individual with confirmed infectious TB or air
originating from an area where a source of aerosolized M. tuberculosis
is present; it does not include exposure to individuals with suspected
infectious TB. OSHA has limited the definition in this way because
several provisions in the proposed standard are triggered by the
occurrence of an exposure incident. For example, under paragraph (g),
Medical Surveillance, the employer is required to provide additional
tuberculin skin testing to each affected employee and to investigate
and document the circumstances surrounding each exposure incident to
determine if changes can be instituted to prevent similar occurrences
in the future. OSHA believes that it would be burdensome and
unnecessary for the employer to conduct follow-up investigations for
those occurrences where an employee's exposure is to an individual
suspected of having infectious TB but for whom infectious disease is
subsequently ruled out.
An example of an exposure incident is an employee entering an AFB
isolation room or area occupied by an individual with confirmed
infectious TB without the employee wearing appropriate personal
respiratory protection equipment. This occurrence would not be defined
under the standard as an exposure incident if the individual in the AFB
isolation room had only suspected infectious TB. If the individual in
AFB isolation room was later confirmed to have infectious TB, the
employee entering the isolation room without appropriate respiratory
equipment would then be considered to have had an exposure incident and
the required medical management and follow-up provisions for an
exposure
[[Page 54280]]
incident under paragraph (g), Medical Surveillance, would be required.
Another example of an exposure incident is a failure of engineering
controls, e.g., the ventilation system in an AFB isolation room housing
an individual with confirmed infectious TB malfunctioned, negative
pressure was lost, and air containing M. tuberculosis was dispelled
into the hall corridor, exposing unprotected employees. Although OSHA
would consider this type of loss of negative pressure in an AFB
isolation room to be an exposure incident, the Agency does not intend
that each opening of the door to an AFB isolation room be considered an
exposure incident, even though some loss of negative pressure may
result when the door to an AFB isolation room is opened. As a practical
matter, OSHA believes it would be infeasible to consider every instance
that a door to an isolation was opened as an exposure incident. In
addition, these losses of negative pressure are generally small, if
doors are kept open only briefly for purposes of entry and exit and are
kept closed at all other times while the room is in operation for TB
isolation as required under the Work Practices and Engineering Controls
paragraph (d)(5)(vi).
There is a significant difference in the meaning of the terms
``exposure incident'' and ``occupational exposure'' as they are used in
this standard. This difference is discussed further under the
definition of ``occupational exposure''.
Filter means a component used in respirators to remove solid or
liquid aerosols from the inspired air. The filter is the medium that
captures the aerosol, preventing it from passing through to the
respirator wearer.
Fit factor is a quantitative measure of the fit of a particular
respirator on a particular individual. Fit factor is derived from the
ratio of the concentration of a challenge agent (or air pressure)
outside of the respirator to the concentration of the test agent (or
air pressure) inside the respirator.
High Efficiency Particulate Air (HEPA) Filter means a specialized
filter that is capable of removing 99.97 percent of particles greater
than or equal to 0.3 micrometer in diameter.
High-hazard procedures are those procedures performed on an
individual with suspected or confirmed infectious tuberculosis in which
the potential for being exposed to M. tuberculosis is increased due to
the induction of coughing or the generation of aerosolized M.
tuberculosis. Such procedures include, but are not limited to, sputum
induction, bronchoscopy, endotracheal intubation or suctioning,
aerosolized administration of pentamidine or other medications, and
pulmonary function testing. They also include autopsy, clinical,
surgical and laboratory procedures that may aerosolize M. tuberculosis.
The procedures listed above present a high hazard because they are
performed on individuals with suspected or confirmed infectious TB or
on specimens or deceased individuals where M. tuberculosis may be
present. For example, some of the procedures listed above, such as
bronchoscopies and pentamidine administration, cause people to cough.
For individuals with pulmonary TB, coughing will increase the
likelihood that they will generate aerosols with a high concentration
of droplet nuclei. In addition, certain autopsy procedures, such as
cutting into a lung containing M. tuberculosis, and certain laboratory
procedures, such as processing infected tissue samples with pressurized
freezants, can generate aerosols containing droplet nuclei. In the
absence of M. tuberculosis, these procedures would not be high-hazard.
For example, endotracheal intubation on an individual who does not have
suspected or confirmed infectious TB would not be considered a high-
hazard procedure.
M. tuberculosis means Mycobacterium tuberculosis, the scientific
name of the bacillus that causes tuberculosis.
Negative Pressure means the relative air pressure difference
between two areas. A room that is under negative pressure has lower
pressure than adjacent areas, which keeps air from flowing out of the
room and into adjacent rooms or areas. Paragraph (d)(5)(i) of Work
Practices and Engineering Controls requires that negative pressure be
maintained in all AFB isolation rooms or areas, and paragraph (d)(4)
requires that all high-hazard procedures be performed in such rooms or
areas. Maintaining negative pressure in such rooms or areas helps to
assure that droplet nuclei are contained and not spread to other areas
of the facility where unprotected employees may be exposed. A further
discussion of this principle can be found in the Summary and
Explanation of paragraph (d), Work Practices and Engineering Controls.
Negative pressure respirator means a respirator in which the air
pressure inside the facepiece is negative during inhalation with
respect to the ambient air pressure outside the respirator. In a
negative pressure respirator, the wearer's inhalation creates a drop in
pressure inside the facepiece, consequently drawing outside air through
the filter and into the respirator.
Occupational exposure is one of the key terms upon which the
proposed standard rests. It contains the criteria that trigger
application of the standard for employees in work settings covered
under the scope of the standard as listed in paragraphs (a)(1) through
(a)(8) and for employees providing the care and services listed in
paragraphs (a)(9) and (a)(10). Although a variety of work settings and
several specific types of work are covered within the scope of the
standard, it is only employees who have ``occupational exposure'' in
those work settings and who are providing the particular services that
must be given the protection mandated by the standard. The exception to
this is that an employer covered under paragraph (a), scope, must
provide medical management and follow-up to other employees who have an
exposure incident.
For purposes of this standard, occupational exposure means
reasonably anticipated contact, which results from the performance of
an employee's duties, with an individual with suspected or confirmed
infectious TB or air that may contain aerosolized M. tuberculosis. An
example of reasonably anticipated contact between an employee and an
individual with suspected or confirmed infectious TB would be an
admissions clerk working in a homeless shelter. In view of the high
incidence of TB among the homeless, it can reasonably be anticipated
that an employee screening people for admission into the shelter would
have contact with a person with infectious TB during the performance of
his or her job duties. Another, more obvious, example would be a
bronchoscopist in a hospital that provides care for individuals with
suspected or confirmed infectious TB. Others could include some
physicians, nurses, paramedics and emergency medical technicians,
health aides, prison guards, and intake workers in the facilities
listed in paragraph (a) of this section. An example of an employee who
would not be reasonably anticipated to have occupational exposure is an
worker, in a covered facility, whose duties were limited to working in
an area where suspected or confirmed TB patients or clients do not go
and where the air would not contain aerosolized Mycobacterium
tuberculosis. The risk of exposure for this employee is comparable to
the exposure potential by the general population.
The term occupational exposure is used differently than the term
exposure incident in the proposed standard. Occupational exposure is
used to define
[[Page 54281]]
a condition of the employee's work and to identify which employees are
affected in a way that can reasonably be anticipated, due to their job
duties, to involve potential exposure to aerosolized M. tuberculosis,
i.e., contact with an individual with suspected or confirmed infectious
TB or with air that may contain aerosolized M. tuberculosis. The intent
of the standard is to prevent exposure to aerosolized M. tuberculosis;
therefore, certain proactive measures are required by the standard,
e.g., training and medical surveillance, when occupational exposure is
present. In order to provide these measures, it is necessary to
identify which employees may be exposed before exposure occurs. The
definition of ``occupational exposure'' is the basis for making this
identification.
An exposure incident, on the other hand, is a discrete event in
which it is known that an employee has had contact with aerosolized M.
tuberculosis, i.e., with an individual with confirmed infectious TB or
air containing aerosolized M. tuberculosis. The term ``exposure
incident'' is used to define those occasions when certain reactive
measures are required by the standard, such as medical management and
follow-up. It is exposure to an individual with confirmed infectious TB
that matters, since it is not necessary to take reactive measures after
being exposed to an individual with suspected infectious TB if that
individual has subsequently been determined not to have infectious TB.
Physician or Other Licensed Health Care Professional means an
individual whose legally permitted scope of practice (i.e., license,
registration, or certification) allows her or him to independently
perform or be delegated to perform some or all of the health care
services required by paragraph (g) of this section. Paragraph (g)
requires that all medical evaluations and procedures and medical
management and follow-up be performed by or under the supervision of a
physician or other licensed health care professional, as appropriate.
OSHA is aware that a variety of health care professionals are licensed
by their respective states to legally perform different medical
provisions required under this proposed standard. This definition
clarifies that it is not OSHA's intent to dictate the specific type of
health care professional to perform the activities required by the
medical surveillance paragraph. OSHA's intent is merely that these
activities be performed by persons who are legally permitted to
independently perform or be delegated to perform some or all of the
health care services required under the medical surveillance provisions
of the standard. Employers wishing to use the services of a variety of
health care providers must be familiar with the licensing laws of their
state to ensure that the activities being performed are within the
scope of that health care provider's licensure.
Powered air-purifying respirator (PAPR) means an air-purifying
respirator that uses a blower to deliver air through the air-purifying
element to the wearer's breathing zone. A PAPR uses a blower to draw
ambient air through a filter and provide this filtered air, under
pressure, to the facepiece of the wearer.
Qualitative fit test means a pass/fail fit test to assess the
adequacy of respirator fit that relies on the respirator wearer's
response. Generally, this assessment of adequacy of respirator fit is
made by determining whether an individual wearing the respirator can
detect the odor, taste, or irritation of a challenge agent introduced
into the vicinity of the wearer's breathing zone.
Quantitative fit test means an assessment of the adequacy of
respirator fit by numerically measuring the amount of leakage into the
respirator. Leakage can be assessed through means such as measuring the
concentration of a challenge agent (or air pressure) outside of the
respirator versus the concentration of the agent (or air pressure)
inside the respirator. The ratio of the two measurements is an index of
the leakage of the seal between the respirator facepiece and the
wearer's face.
Research laboratory is defined as a laboratory that propagates and
manipulates cultures of M. tuberculosis in large volumes or high
concentrations that are in excess of those used for identification and
typing activities common to clinical laboratories. The purpose of this
definition is to distinguish research laboratories from clinical
laboratories. Under paragraph (e) of the proposed standard, research
laboratories are required to meet additional provisions beyond those
required for clinical laboratories (e.g., use of a hazard warning sign
incorporating the biohazard symbol when materials containing M.
tuberculosis are present in the laboratory and use of two sets of self-
closing doors for entry into the work area from access corridors).
These additional requirements are proposed due to the higher degree of
hazard that may be present in research laboratories as a result of the
presence of research materials that may contain M. tuberculosis in
larger volumes and higher concentrations than would normally be found
in diagnostic specimens or cultures in clinical laboratories.
Respirator means a device worn by an individual and intended to
provide the wearer with respiratory protection against inhalation of
airborne contaminants. While the term ``respirator'' may be used in
medical situations to refer to a device that provides breathing
assistance to an individual who is experiencing breathing difficulty,
this section utilizes this term only in reference to the type of
protective device defined above.
Suspected infectious tuberculosis means a potential disease state
in which an individual is known, or with reasonable diligence should be
known, by the employer to have one or more of the following conditions,
unless the individual's condition has been medically determined to
result from a cause other than TB: (1) to be infected with M.
tuberculosis and to have the signs or symptoms of TB; (2) to have a
positive acid-fast bacilli (AFB) smear; or (3) to have a persistent
cough lasting 3 or more weeks and two or more symptoms of active TB
(e.g., bloody sputum, night sweats, weight loss, fever, anorexia). An
individual with suspected infectious TB has neither confirmed
infectious TB nor has he or she been medically determined to be
noninfectious.
Suspected infectious TB is another key term in the proposed
standard. The presence of a person with suspected infectious TB
triggers and is associated with a number of the provisions required of
employers. Applying the criteria associated with suspected infectious
TB is the first step in the early identification of individuals with
infectious TB and is therefore a key factor in the elimination and
minimization of occupational transmission of TB. Therefore, for
purposes of implementing the standard it is important that what
constitutes ``suspected infectious TB'' is clear.
The first criterion in identifying an individual as having
suspected infectious TB is the presence of TB infection and the signs
and symptoms of active TB. Under the second criterion, an individual
would be suspected of having infectious TB if that individual had a
positive AFB smear. The third criterion is based primarily on
observation of an individual. The CDC states that:
* * * A diagnosis of TB may be considered for any patient who
has a persistent cough (i.e., a cough lasting for 3
weeks) or other signs or symptoms compatible with active TB (e.g.,
bloody sputum, night sweats, weight loss, anorexia
[[Page 54282]]
or fever). * * * Diagnostic measures for identifying TB should be
conducted for patients in whom active TB is being considered. These
measures include obtaining a medical history and performing a
physical examination, PPD skin test, chest radiograph, and
microscopic examination and culture of sputum or other appropriate
specimens. (Ex. 4B)
OSHA has relied on the CDC's list of symptoms, but does not agree that
employers need only ``consider'' a TB diagnosis when any of the
symptoms appear. The Agency believes that requiring employers merely to
consider a TB diagnosis under these circumstances may allow too many
individuals with infectious TB to slip through this screen and remain
unidentified. In addition, the CDC recommendations do not identify the
minimum number of signs or symptoms that should trigger employer
concern. The problem with the CDC's approach is that the signs and
symptoms are so general that they would be difficult to apply in many
of the occupational exposure circumstances covered by the standard. For
example, if OSHA required employers to identify each individual with
even one of the signs or symptoms of TB as having suspected infectious
TB, too many individuals would be likely to be identified, thereby
wasting valuable health care resources. For these reasons, OSHA has
proposed that employers be required to determine that an individual has
suspected infectious TB when the individual has a prolonged cough and
at least two of the other signs or symptoms of infectious TB. The
Agency believes that requiring the employer to identify individuals as
suspect cases when they have only a prolonged cough, which is the
primary mode of transmission, and at least 2 other signs or symptoms
strikes the appropriate balance between over inclusion and under
inclusion, i.e., between considering almost every individual in poor
health as a suspect case and missing individuals who should be
suspected of having infectious TB. OSHA believes that setting forth
these more definitive criteria will meet the needs of the many
employers covered by this standard who will not have skilled medical
persons making initial determinations about whether or not an
individual has suspected infectious TB. Employer who are in a position
to make medical determinations are permitted by the standard to rule
out infectious TB by determining that a given individual's signs and
symptoms are the result of a cause other than TB.
That an employer knows or with reasonable diligence should know
that an individual meets one or more of these criteria means that an
employer must utilize the means at his or her disposal to gather
relevant information about the individual. For example, the employer
may have access to the medical records of the individual or may
question an individual who has signs or symptoms of TB in order to
obtain information about the individual, such as skin test status, AFB
smear status, and so forth. How much questioning the employer might do
depends on the work setting. For example, a hospital will have intake
procedures that include asking questions, as will most homeless
shelters and other fixed work sites. In other work settings, such as
the many places in which emergency medical services and home health
care are provided to unidentified individuals with infectious TB, the
employer's obligation will be to respond when an employee notices signs
or symptoms compatible with TB. In many of these instances, it is the
training employees receive in identifying individuals with suspected TB
that will be the most important factor.
In addition, as noted above, an individual who meets one or more of
the above criteria but whose condition has been medically determined to
result from a cause other than TB need not be considered to have
suspected infectious TB. For example, a physician or other licensed
health care professional, as appropriate, could determine that the
signs and symptoms exhibited by the individual were the result, for
example, of pneumonia and not TB.
Tight-fitting respirator means a respiratory inlet covering that is
designed to form a complete seal with the face. A half-facepiece covers
the nose and mouth while a full facepiece covers the nose, mouth, and
eyes.
Tuberculosis (TB) means a disease caused by M. tuberculosis.
Tuberculosis infection means a condition in which living M.
tuberculosis bacilli are present in the body, without producing
clinically active disease. Although the infected individual has a
positive tuberculin skin test reaction, the individual may have no
symptoms related to the infection and may not be capable of
transmitting the disease.
Tuberculosis disease is a condition in which living M. tuberculosis
bacilli are present in the body, producing clinical illness. The
individual may or may not be infectious.
Tuberculin skin test means a method used to evaluate the likelihood
that a person is infected with M. tuberculosis. The method utilizes an
intradermal injection of tuberculin antigen with subsequent measurement
of reaction induration. It is also referred to as a PPD skin test.
Two-step testing is a baseline skin testing procedure used to
differentiate between a boosted skin test reaction and a skin test
reaction that signifies a new infection. If the initial skin test is
negative, a second skin test is administered 1 to 3 weeks later. If the
second skin test is positive, the reaction is probably due to boosting.
If the second skin test is negative, the individual is considered to be
not infected. A subsequent positive skin test in this individual would
thus indicate a new infection. Boosting is discussed in more detail in
connection with the Medical Surveillance paragraph.
Paragraph (k) Dates
As proposed, the final rule would become effective ninety (90) days
after publication in the Federal Register. This will allow time for
public distribution and give employers time to familiarize themselves
with the standard. The various provisions have phased-in effective
dates.
The employer's initial duty under the standard is the exposure
determination and establishment of the written Exposure Control Plan
required by paragraph (c) of this section. The plan would need to be
completed 30 days after the effective date.
Thirty days later, 60 days after the effective date, paragraphs
(h)(3), Information and Training, (g) Medical Surveillance, and (i)
Recordkeeping would take effect.
Ninety (90) days after the effective date, the work practice
procedures and engineering controls required by paragraph (d) (in work
settings other than those noted below), the respiratory protection
required by paragraph (f), and the labels and signs required by
paragraphs (h) (1) and (2) would take effect. The work practices that
are directly related to the engineering controls would have to be
implemented as soon as the engineering controls were functional.
Finally, the requirements for clinical and research laboratories
contained in paragraph (e) would also take effect 90 days after the
effective date.
For businesses with fewer than 20 employees, the engineering
controls required by paragraph (d) of this section would take effect
270 days after the effective date. As noted above, the work practices
directly related to the engineering controls being installed in
accordance with paragraph (d) of this section must be implemented as
soon as the engineering controls are
[[Page 54283]]
implemented. Since engineering controls may necessitate more extensive
planning than is required to comply with other provisions of the
standard, OSHA is proposing an extended phase-in for the smallest
employers.
Since many employers have many of these provisions already in
effect through current infection control plans, OSHA believes that
these dates provide adequate time for compliance. Nevertheless, OSHA
seeks comment on the appropriateness of the dates for compliance with
the various provisions of the standard.
XI. Public Participation--Notice of Hearing
Interested persons are invited to submit written data, views, and
arguments with respect to this proposed standard. These comments must
be postmarked on or before December 16, 1997, and submitted in
quadruplicate to the Docket Officer, Docket No. H-371, Room N2625, U.S.
Department of Labor, 200 Constitution Avenue NW., Washington, DC 20210.
Comments limited to 10 pages or less also may be transmitted by
facsimile to (202) 219-5046, provided the original and three copies are
sent to the Docket Officer thereafter.
Written submissions must clearly identify the provisions of the
proposal that are being addressed and the position taken with respect
to each issue. The data, views, and arguments that are submitted will
be available for public inspection and copying at the above address.
All timely written submissions will be made a part of the record of the
proceeding.
Pursuant to section 6(b)(3) of the Act, an opportunity to submit
oral testimony concerning the issues raised by the proposed standard
will be provided at an informal public hearing scheduled to begin at
10:00 A.M. on February 3, 1998, in Washington, DC in the Auditorium of
the Frances Perkins Building, U.S. Department of Labor, 200
Constitution Avenue, NW., Washington, DC 20210.
Notice of Intention to Appear
All persons desiring to participate at the hearings must file in
quadruplicate a notice of intention to appear postmarked on or before
December 16, 1997 addressed to the Docket Officer, Docket No. H-371,
Room N-2625, U.S. Department of Labor, 200 Constitution Avenue, NW.,
Washington, DC 20210; telephone (202) 219-7894. The Notice of Intention
to Appear also may be transmitted by facsimile to (202) 219-5046,
provided the original and 3 copies of the notice are sent to the above
address thereafter.
The Notices of Intention to Appear, which will be available for
inspection and copying at the OSHA Docket Office, must contain the
following information:
(1) The name, address, and telephone number of each person to
appear;
(2) The hearing site that the party is requesting to attend;
(3) The capacity in which the person will appear;
(4) The approximate amount of time requested for the presentation;
(5) The specific issues that will be addressed;
(6) A detailed statement of the position that will be taken with
respect to each issue addressed;
(7) Whether the party intends to submit documentary evidence, and
if so, a brief summary of that evidence; and
(8) Whether the party wishes to testify on the days set aside to
focus on homeless shelters.
Filing of Testimony and Evidence Before Hearings
Any party requesting more than 10 minutes for a presentation at the
hearing, or who will submit documentary evidence, must provide in
quadruplicate the complete text of the testimony, including any
documentary evidence to be presented at the hearing to the Docket
Officer at the above address. This material must be postmarked by
December 31, 1997 and will be available for inspection and copying at
the OSHA Docket Office. Each such submission will be reviewed in light
of the amount of time requested in the Notice of Intention to Appear.
In those instances where the information contained in the submission
does not justify the amount of time requested, a more appropriate
amount of time will be allocated and the participant will be notified
of that fact.
Any party who has not substantially complied with this requirement
may be limited to a 10-minute presentation. Any party who has not filed
a Notice of Intention to Appear may be allowed to testify, as time
permits, at the discretion of the Administrative Law Judge.
OSHA emphasizes that the hearing is open to the public, and that
interested persons are welcome to attend. However, only persons who
have filed proper notices of intention to appear will be entitled to
ask questions and otherwise participate fully in the proceeding.
Conduct and Nature of Hearings
The hearings will commence at 10:00 a.m. on February 3, 1998. At
that time any procedural matters relating to the proceeding will be
resolved.
The nature of an informal hearing is established in the legislative
history of section 6 of the Act and is reflected by the OSHA hearing
regulations (see 29 CFR 1911.15 (a)). Although the presiding officer is
an Administrative Law Judge and questioning by interested persons is
allowed on crucial issues, the proceeding shall remain informal and
legislative in type. The essential intent is to provide an opportunity
for effective oral presentations that can proceed expeditiously in the
absence of rigid procedures that would impede or protract the
rulemaking process.
Additionally, since the hearing is primarily for information
gathering and clarification, it is an informal administrative
proceeding, rather than an adjudicative one. The technical rules of
evidence, for example, do not apply. The regulations that govern
hearings and the pre-hearing guidelines to be issued for this hearing
will ensure fairness and due process and also facilitate the
development of a clear, accurate and complete record. Those rules and
guidelines will be interpreted in a manner that furthers that
development. Thus, questions of relevance, procedure and participation
generally will be decided so as to favor development of the record.
The hearing will be conducted in accordance with 29 CFR Part 1911.
The hearing will be presided over by an Administrative Law Judge who
makes no recommendation on the merits of OSHA's proposal. The
responsibility of the Administrative Law Judge is to ensure that the
hearing proceeds at a reasonable pace and in an orderly manner. The
Administrative Law Judge, therefore, will have all the powers necessary
and appropriate to conduct a full and fair informal hearing as provided
in 29 CFR Part 1911 and the prehearing guidelines, including the
powers:
(1) To regulate the course of the proceedings;
(2) To dispose of procedural requests, objections, and comparable
matters;
(3) To confine the presentation to the matters pertinent to the
issues raised;
(4) To regulate the conduct of those present at the hearing by
appropriate means;
(5) At the Judge's discretion, to question and permit the
questioning of any witness and to limit the time for questioning; and
(6) At the Judges's discretion, to keep the record open for a
reasonable, stated time to written information and additional data,
views and arguments from any person who has participated in the oral
proceeding.
[[Page 54284]]
Information on Homeless Shelter Issues for the Public Hearing
OSHA seeks to gather additional information related to homeless
shelters during the written comment period and the public hearing. OSHA
recognizes the unique service provided by homeless shelters, yet is
also aware that shelters serve a client population that has been
identified as possessing a high prevalence of active TB. OSHA is
seeking information on all aspects of TB and employee protection
against occupational transmission of TB in homeless shelters (e.g.,
means successfully being used by shelters to achieve early
identification of shelter clients with suspected or confirmed
infectious TB; successful programs currently being used to protect
employees against occupational transmission of TB).
The Agency intends to designate a special session during the
Washington, D.C. hearing to focus on the issues surrounding homeless
shelters. We encourage hearing participants whose primary testimony
will involve homeless shelters to indicate this in their Notice of
Intention to Appear; OSHA will attempt to schedule these participants
on the day(s) of the hearing set aside to focus on homeless shelters.
Other participants whose testimony will not be primarily on homeless
shelter issues but who wish to address the topic of homeless shelters
will be scheduled another day, but they may enter a separate statement
in the record during this period. In any case, participants are free to
discuss homeless shelters or any other issue related to this proposed
standard whenever they present their testimony.
Certification of Record and Final Determination After Hearing
Following the close of the posthearing comment period, the
presiding Administrative Law Judge will certify the record to the
Assistant Secretary of Labor for Occupational Safety and Health. The
Administrative Law Judge does not make or recommend any decisions as to
the content of the final standard.
The proposed standard will be reviewed in light of all testimony
and written submissions received as part of the record, and a standard
will be issued based on the entire record of the proceeding, including
the written comments and data received from the public.
List of Subjects
29 CFR Part 1910
Health professionals, Occupational safety and health, Reporting and
recordkeeping requirements, Tuberculosis.
XII. Authority and Signature
This document was prepared under the direction of Greg Watchman,
Acting Assistant Secretary of Labor, 200 Constitution Avenue, N.W.,
Washington, D.C., 20210.
It is issued under sections 4, 6, and 8 of the Occupational Safety
and Health Act of 1970 (29 U.S.C. 653, 655, 657), Secretary of Labor's
Order 1-90 (55 FR 9033) and 29 CFR Part 1911.
Signed at Washington, DC, this 15th day of September, 1997.
Greg Watchman,
Acting Assistant Secretary of Labor.
XIII. The Proposed Standard
General Industry
Part 1910 of Title 29 of the Code of Federal Regulations is
proposed to be amended as follows:
PART 1910--[AMENDED]
Subpart Z--[Amended]
1. The general authority citation for Subpart Z of 29 CFR Part 1910
continues to read as follows and a new citation for Sec. 1910.1035 is
added:
Authority: Secs. 6 and 8, Occupational Safety and Health Act, 29
U.S.C. 655, 657, Secretary of Labor's Orders Nos. 12-71 (36 FR
8754), 8-76 (41 FR 25059), or 9-83 (48 FR 35736), as applicable; and
29 CFR Part 1911.
* * * * *
Section 1910.1035 also issued under 29 U.S.C. 653.
* * * * *
2. Section 1910.1035 is added to read as follows:
Sec. 1910.1035 Tuberculosis
(a) Scope. This section applies to occupational exposure to
tuberculosis (TB) occurring:
(1) In hospitals;
(2) In long term care facilities for the elderly;
(3) In correctional facilities and other facilities that house
inmates or detainees;
(4) In hospices;
(5) In shelters for the homeless;
(6) In facilities that offer treatment for drug abuse;
(7) In facilities where high-hazard procedures (as defined by this
section) are performed;
(8) In laboratories that handle specimens that may contain M.
tuberculosis, or process or maintain the resulting cultures, or perform
related activity that may result in the aerosolization of M.
tuberculosis;
Note to paragraph (a)(8): Occupational exposure incurred in any
of the work settings listed in paragraphs (a)(1) through (a)(8) of
this section by temporary or contract employees or by personnel who
service or repair air systems or equipment or who renovate, repair,
or maintain areas of buildings that may reasonably be anticipated to
contain aerosolized M. tuberculosis is covered by this section.
(9) During the provision of social work, social welfare services,
teaching, law enforcement or legal services if the services are
provided in any of the work settings listed in paragraphs (a)(1)
through (a)(8) of this section, or in residences, to individuals who
are in AFB isolation or are segregated or otherwise confined due to
having suspected or confirmed infectious TB.
(10) During the provision of emergency medical services, home
health care and home-based hospice care.
(b) Application. An employer covered under paragraph (a) of this
section, Scope (other than the operator of a laboratory), may choose to
comply only with the provisions of appendix A to this section if the
Exposure Control Plan demonstrates that his or her facility or work
setting: (1) Does not admit or provide medical services to individuals
with suspected or confirmed infectious TB; and
(2) Has had no case of confirmed infectious TB in the past 12
months; and
(3) Is located in a county that, in the past 2 years, has had 0
cases of confirmed infectious TB reported in one year and fewer than 6
cases of confirmed infectious TB reported in the other year.
(c) Exposure control--(1) Exposure determination. (i) Each employer
who has any employee with occupational exposure shall prepare an
exposure determination that contains the following:
(A) A list of the job classifications in which all employees have
occupational exposure; and
(B) A list of the job classifications in which some employees have
occupational exposure, and a list of all tasks and procedures (or
groups of closely related tasks and procedures) that these employees
perform and that involve occupational exposure.
[[Page 54285]]
(ii) The exposure determination shall be made without regard to the
use of respiratory protection.
(2) Exposure Control Plan. (i) Each employer who has any employee
with occupational exposure shall establish a written Exposure Control
Plan that must include:
(A) The exposure determination required by paragraph (c)(1) of this
section;
(B) Procedures for providing information about individuals with
suspected or confirmed infectious TB or about air that may reasonably
be anticipated to contain aerosolized M. tuberculosis to occupationally
exposed employees who need this information in order to take proper
precautions; and
(C) Procedures for reporting an exposure incident, including
procedures specifying the individual to whom the incident is to be
reported, and procedures for evaluating the circumstances surrounding
the exposure incident.
(ii) Each employer who transfers individuals with suspected or
confirmed infectious TB to a facility with AFB isolation capabilities
shall include in the Exposure Control Plan procedures for prompt
identification, masking or segregation, and transfer of such
individuals.
Note to paragraph (c)(2)(ii): An employer's duties regarding
transfer will vary with the type of facility the employer operates
and the work performed by his or her employees. For example, the
transfer responsibilities of hospitals, long-term care facilities
for the elderly, correctional facilities, and hospices may include
contacting the receiving facility, providing transport, and taking
other steps to ensure that the individual with suspected or
confirmed infectious TB reaches the receiving facility. By contrast,
the responsibilities of facilities that do not maintain custody over
individuals, such as homeless shelters or facilities that offer
treatment for drug abuse, might only include providing information
about the receiving facility, contacting the facility, and providing
directions to the facility.
(iii) Each employer in whose facility individuals with suspected or
confirmed infectious TB are admitted or provided medical services shall
include each of the following provisions in the Exposure Control Plan:
(A) Procedures for prompt identification of individuals with
suspected or confirmed infectious TB;
(B) Procedures for isolating and managing the care of individuals
with suspected or confirmed infectious TB, including:
(1) Minimizing the time an individual with suspected or confirmed
infectious TB remains outside of an AFB isolation room or area (e.g.,
in an emergency room);
(2) Minimizing employee exposure in AFB isolation rooms or areas by
combining tasks to limit the number of entries into the room or area
and by minimizing the number of employees who must enter and minimizing
the time they spend in the room or area;
(3) Delaying elective transport or relocation within the facility
of an individual with suspected or confirmed infectious TB. Procedures
are to be established to assure that, to the extent feasible, services
and procedures for individuals with suspected or confirmed infectious
TB are brought into or conducted in an AFB isolation room or area;
(4) Using properly-fitted masks (e.g., surgical masks, valveless
respirators) on individuals with suspected or confirmed infectious TB
or transporting such individuals in portable containment engineering
controls when relocation or transport outside of AFB isolation rooms or
areas is unavoidable. Procedures are to be established to assure that
the individual is returned to an AFB isolation room or area as soon as
is practical after completion of the service or procedure;
(5) Delaying elective high-hazard procedures or surgery until an
individual with suspected or confirmed infectious TB is determined to
be noninfectious;
(C) A list of all high-hazard procedures, if any, performed in the
work setting; and
(D) A schedule for inspection, maintenance, and performance
monitoring of engineering controls (see appendix E to this section).
(iv) Each employer who operates a laboratory shall include in the
Exposure Control Plan a determination from the director of the
laboratory as to whether the facility should operate at Biosafety Level
2 or 3 containment according to current CDC recommendations (CDC/NIH
Biosafety in Microbiological and Biomedical Laboratories). The
laboratory director shall determine and document the need for:
(A) Controlled access;
(B) Anterooms;
(C) Sealed windows;
(D) Directional airflow;
(E) Measures to prevent recirculation of laboratory exhaust air;
(F) Filtration of exhaust air before discharge outside; and
(G) Thimble exhaust connections for biological safety cabinets.
(v) Each employer who provides home health care or home-based
hospice care shall include in the Exposure Control Plan procedures for
prompt identification of individuals with suspected or confirmed
infectious TB and procedures for minimizing employee exposure to such
individuals; a list of the high-hazard procedures, if any, performed in
the work setting; and procedures for delaying elective high-hazard
procedures or surgery until the individual is noninfectious.
(vi) Each employer who claims reduced responsibilities related to
paragraph (b), Application, or paragraph (g)(3)(iii)(D), Medical
Surveillance, of this section shall document in the Exposure Control
Plan the number of individuals with confirmed infectious tuberculosis
encountered in the work setting in the past 12 months.
(vii) The Exposure Control Plan shall be:
(A) Accessible to employees in accordance with 29 CFR 1910.20(e);
(B) Reviewed at least annually and updated whenever necessary to
reflect new or modified tasks, procedures, or engineering controls that
affect occupational exposure and to reflect new or revised employee job
classifications with occupational exposure; and
(C) Made available for examination and copying to the Assistant
Secretary and/or the Director upon request.
(d) Work Practices and Engineering Controls. (1) Work practices and
engineering controls shall be used to eliminate or minimize employee
exposures to M. tuberculosis.
(2) The work practices in the Exposure Control Plan shall be
implemented.
(3) Individuals with suspected or confirmed infectious TB shall be
identified, and except in settings where home health care or home-based
hospice care is being provided, shall be:
(i) Masked or segregated in such a manner that contact with
employees who are not wearing respiratory protection is eliminated or
minimized until transfer or placement in an AFB isolation room or area
can be accomplished; and
(ii) Placed in an AFB isolation room or area or transferred to a
facility with AFB isolation rooms or areas within 5 hours from the time
of identification, or temporarily placed in AFB isolation within 5
hours until placement or transfer can be accomplished as soon as
possible thereafter.
(4) High-hazard procedures shall be conducted in an AFB isolation
room or area.
(5) Engineering controls shall be used in facilities that admit or
provide medical services or AFB isolation to individuals with suspected
or confirmed infectious TB except in
[[Page 54286]]
settings where home health care or home-based hospice care is being
provided.
(i) Negative pressure shall be maintained in AFB isolation rooms or
areas.
(ii) Negative pressure shall be qualitatively demonstrated (e.g.,
by smoke trails) daily while a room or area is in use for TB isolation
(see appendix G to this section).
(iii) Engineering controls shall be maintained, and inspected and
performance monitored for filter loading and leakage every 6 months,
whenever filters are changed, and more often if necessary to maintain
effectiveness (see appendix E to this section).
(iv) Air from AFB isolation rooms or areas shall be exhausted
directly outside, away from intake vents, employees, and the general
public. Air that cannot be exhausted in such a manner or must be
recirculated must pass through HEPA filters before discharge or
recirculation.
(v) Ducts carrying air that may reasonably be anticipated to
contain aerosolized M. tuberculosis shall be maintained under negative
pressure for their entire length before in-duct HEPA filtration or
until the ducts exit the building for discharge.
(vi) Doors and windows of AFB isolation rooms or areas shall be
kept closed while in use for TB isolation, except when doors are opened
for entering or exiting and when windows are part of the ventilation
system being used to achieve negative pressure.
(vii) When an AFB isolation room or area is vacated by an
individual with suspected or confirmed infectious TB, the room or area
shall be ventilated according to current CDC recommendations for a
removal efficiency of 99.9% before permitting employees to enter
without respiratory protection (see appendix C to this section).
(6) The employer shall provide information about the TB hazard to
any contractor who provides temporary or contract employees who may
incur occupational exposure so that the contractor can institute
precautions to protect his or her employees.
(e) Clinical and Research Laboratories. (1) This paragraph applies
to clinical and research laboratories that engage in the culture,
production, concentration, experimentation, or manipulation of M.
tuberculosis. The requirements in this paragraph apply in addition to
the other requirements of the standard.
(2) Clinical and research laboratories shall meet the following
criteria:
(i) Standard microbiological practices.
(A) Procedures shall be performed in a manner that minimizes the
creation of aerosols.
(B) Mouth pipetting shall be prohibited.
(C) Work surfaces and laboratory equipment shall be decontaminated
at the end of each shift and after any spill of viable material.
(D) Cultures, stocks and other wastes contaminated with M.
tuberculosis shall be decontaminated before disposal by a
decontamination method, such as autoclaving, known to effectively
destroy M. tuberculosis. Materials to be decontaminated outside of the
immediate laboratory shall be placed in a durable, leakproof container,
closed and sealed for transport from the laboratory and labeled or
color-coded in accordance with paragraph (h)(1)(ii) of this section.
(ii) Special practices. (A) Access to the laboratory shall be
limited by the laboratory director when work with M. tuberculosis is in
progress.
(B) A biosafety manual that includes procedures for spill
management shall be adopted. The employer shall review the manual as
necessary and at least annually. The employer shall update the
biosafety manual as necessary to reflect changes in the work setting.
Employees shall be advised of potential hazards, shall be required to
read instructions on practices and procedures, and shall be required to
follow them.
(C) Cultures, tissues, or specimens of body fluids contaminated
with M. tuberculosis shall be placed in a container that prevents
leakage during collection, handling, processing, storage, transport, or
shipping.
(D) All spills shall be immediately contained and cleaned up by
employees who are properly trained and equipped to work with
potentially concentrated M. tuberculosis. A spill or accident that
results in an exposure incident shall be reported immediately to the
laboratory director or other designated person.
(E) When materials containing or animals infected with M.
tuberculosis are present in the laboratory or containment module, a
hazard warning sign, in accordance with paragraph (h)(2)(iv),
incorporating the universal biohazard symbol, shall be posted on all
laboratory and animal room access doors.
(iii) Containment equipment. (A) Certified biological safety
cabinets (Class 2) shall be used whenever procedures with a potential
for generating aerosols of M. tuberculosis are conducted or whenever
high concentrations or large volumes of M. tuberculosis are used. Such
materials may be centrifuged in the open laboratory if sealed rotor
heads or centrifuge safety cups are used, and if these rotors or safety
cups are opened in a biological safety cabinet.
(B) Biological safety cabinets shall be certified when installed,
annually thereafter, whenever they are moved, and whenever filters are
changed.
(iv) Laboratory facilities. A method for decontamination of wastes
contaminated with M. tuberculosis (e.g., autoclave, chemical
disinfection, incinerator, or other decontamination system known to
effectively destroy M. tuberculosis) shall be available within or as
near as feasible to the work area.
(3) Research laboratories shall meet the following additional
criteria:
(i) Special practices. (A) Laboratory doors shall be kept closed
when work involving M. tuberculosis is in progress.
(B) Access to the work area shall be limited to authorized persons.
Written policies and procedures shall be established so that only
persons who have been advised of the potential biohazard, who meet any
specific entry requirements, and who comply with all entry and exit
procedures shall be allowed to enter the work areas and animal rooms.
(C) Respiratory protection shall be worn when aerosols cannot be
safely contained (e.g., when aerosols are generated outside of a
biological safety cabinet).
(ii) Containment equipment. Certified biological safety cabinets
(Class 2 or 3) or appropriate combinations of personal protection or
physical containment devices, such as respirators, centrifuge safety
cups, sealed centrifuge rotors, and containment caging for animals,
shall be used for manipulations of cultures and those clinical or
environmental materials that may be a source of aerosols containing M.
tuberculosis; aerosol challenge of animals with M. tuberculosis;
harvesting of tissues or fluids from animals infected with M.
tuberculosis; or the necropsy of animals infected with M. tuberculosis.
(iii) Laboratory facilities. (A) The laboratory shall be separated
from areas that are open to unrestricted traffic flow within the
building. Passage through two sets of self-closing doors shall be
required for entry into the work area from access corridors or other
contiguous areas.
(B) Windows in the laboratory shall be closed and sealed.
(C) A ducted exhaust air ventilation system shall be provided. This
system shall create directional airflow that draws air from ``clean''
areas into the laboratory toward ``contaminated'' areas. The employer
shall verify the proper direction of the airflow (i.e., into
[[Page 54287]]
the work area) at least every six months. The exhaust air shall not be
recirculated to any other area of the building, shall be discharged to
the outside, and shall be dispersed away from occupied areas and air
intakes.
(D) The high efficiency particulate air (HEPA)-filtered exhaust air
from Class 2 or Class 3 biological safety cabinets shall be discharged
directly to the outside or through the building exhaust system. If the
HEPA-filtered exhaust air from Class 2 or 3 biological safety cabinets
is to be discharged to the outside through the building exhaust air
system, it shall be connected to this system in a manner (e.g., thimble
units) that avoids any interference with the air balance of the
cabinets or building exhaust system.
(E) Continuous flow centrifuges or other equipment that may produce
aerosols shall be contained in devices that exhaust air through HEPA
filters before discharge into the laboratory.
(f) Respiratory Protection--(1) General. (i) Each employer shall
provide a respirator to each employee who:
(A) Enters an AFB isolation room or area in use for TB isolation;
(B) Is present during the performance of procedures or services for
an individual with suspected or confirmed infectious TB who is not
masked;
(C) Transports an individual with suspected or confirmed infectious
TB in an enclosed vehicle (e.g., ambulance, helicopter) or who
transports an individual with suspected or confirmed infectious TB
within the facility when that individual is not masked;
(D) Repairs, replaces, or maintains air systems or equipment that
may reasonably be anticipated to contain aerosolized M. tuberculosis;
(E) Is working in an area where an unmasked individual with
suspected or confirmed infectious TB has been segregated or otherwise
confined (e.g., while awaiting transfer); or
(F) Is working in a residence where an individual with suspected or
confirmed infectious TB is known to be present.
(ii) Each employer who operates a research laboratory shall provide
a respirator to each employee who is present when aerosols of M.
tuberculosis cannot be safely contained (e.g., when aerosols are
generated outside of a biological safety cabinet).
(iii) The employer shall provide the respirator at no cost to the
employee and shall assure that the employee uses the respirator in
accordance with the requirements of this section.
(iv) The employer shall assure that the employee dons the
respirator before entering any of the work settings or performing any
of the tasks set forth in paragraphs (f)(1)(i) and (f)(1)(ii) of this
section and uses it until leaving the work setting or completing the
task, regardless of other control measures in place.
(2) Respiratory Protection Program. (i) Each employer who has any
employee whose occupational exposure is based on entering any of the
work settings or performing any of the tasks described in paragraph
(f)(1) of this section shall establish and implement a written
respiratory protection program that assures respirators are properly
selected, fitted, used, and maintained. The program shall include the
following elements:
(A) Procedures for selecting the appropriate respirators for use in
the work setting;
(B) A determination of each employee's ability to wear a
respirator, as required under paragraph (g)(3)(ii) of this section,
Medical Surveillance, for each employee required to wear a respirator;
(C) Procedures for the proper use of respirators;
(D) Fit testing procedures for tight-fitting respirators;
(E) Procedures and schedules for cleaning, disinfecting, storing,
inspecting, repairing, or otherwise maintaining respirators;
(F) Training of employees to assure the proper use and maintenance
of the respirator, as required under paragraph (h) of this section,
Communication of Hazards and Training; and
(G) Procedures for periodically evaluating the effectiveness of the
program.
(ii) The employer shall designate a person qualified by appropriate
training or experience to be responsible for the administration of the
respiratory protection program and for conducting the periodic
evaluations of its effectiveness.
(iii) The employer shall review and update the written program as
necessary to reflect current workplace conditions and respirator use.
(iv) The employer shall, upon request, make the written respiratory
protection program available to affected employees, their designated
representatives, the Assistant Secretary, and the Director. A copy of
the program shall be submitted to the Assistant Secretary and/or the
Director, if requested.
(3) Respirator Selection. (i) The employer shall select and provide
properly fitted negative pressure or more protective respirators.
Negative pressure respirators shall be capable of being:
(A) Qualitatively or quantitatively fit tested in a reliable way to
verify a face-seal leakage of no more than 10%; and
(B) Fit checked by the employee each time the respirator is donned.
(ii) The employer shall select a respirator that will function
effectively in the conditions of the work setting. In addition to
meeting the criteria in paragraph (f)(3)(i) of this section, the
respirator shall be, at a minimum, either a HEPA respirator selected
from among those jointly approved as acceptable by the Mine Safety and
Health Administration and by the National Institute for Occupational
Safety and Health (NIOSH) under the provisions of 30 CFR part 11, or an
N95 respirator certified by NIOSH under the provisions of 42 CFR part
84.
(4) Respirator Use. (i) The employer shall not permit any
respirator that depends on a tight face-to-facepiece seal for
effectiveness to be worn by employees having any condition that
prevents such a seal. Examples of these conditions include, but are not
limited to, facial hair that comes between the sealing surface of the
facepiece and the face or if facial hair interferes with valve
function, absence of normally worn dentures, facial scars, or headgear
that projects under the facepiece seal.
(ii) The employer shall assure that each employee who wears
corrective glasses or goggles wears them in a manner that does not
interfere with the seal of the facepiece to the face of the wearer.
(iii) Disposable respirators shall be discarded when excessive
resistance, physical damage, or any other condition renders the
respirator unsuitable for use.
(iv) The employer shall assure that each employee, upon donning a
tight-fitting respirator, performs a facepiece fit check prior to
entering a work area where respirators are required. The procedures in
appendix B to this section or other procedures recommended by the
respirator manufacturer that provide protection equivalent to that
provided by the procedures in appendix B shall be used.
(v) Respirators shall be immediately repaired, or discarded and
replaced, when they are no longer in proper working condition.
(vi) The employer shall permit each employee to leave the
respirator use area as soon as practical to:
(A) Change the filter elements or replace the respirator whenever
the ability of the respirator to function effectively is compromised or
the employee detects a change in breathing resistance; or
[[Page 54288]]
(B) Wash his or her face and respirator facepiece as necessary to
prevent skin irritation associated with respirator use.
(vii) Each employee required to wear a respirator under this
section shall be evaluated in accordance with paragraph (g), Medical
Surveillance, of this section.
(viii) No employee shall be assigned a task requiring the use of a
respirator if, based upon the employee's most recent evaluation, the
physician or other licensed health care professional, as appropriate,
determines that the employee will be unable to function adequately
while wearing a respirator. If the physician or other licensed health
care professional, as appropriate, determines that the employee's job
activities must be limited, or that the employee must be removed from
the employee's current job because of the employee's inability to wear
a respirator, the limitation or removal shall be performed in
accordance with paragraph (g)(5)(iii) of this section.
(5) Fit Testing. (i) The employer shall perform either quantitative
or qualitative face fit tests in accordance with the procedures
outlined in appendix B to this section.
(ii) The employer shall assure that each employee who must wear a
tight-fitting respirator passes a fit test:
(A) At the time of initial fitting;
(B) Whenever changes occur in the employee's facial characteristics
which affect the fit of the respirator;
(C) Whenever a different size or make of respirator is used; and
(D) At least annually thereafter unless the annual determination
required under paragraph (g)(3)(ii)(A), Medical Surveillance, of this
section indicates that the annual fit test is not necessary.
(iii) When quantitative fit testing is performed, the employer
shall not permit an employee to wear a tight-fitting half-mask
respirator unless a minimum fit factor of one hundred (100) is obtained
in the test chamber.
(6) Maintenance and care of reusable and powered air purifying
respirators. (i) Respirators shall be cleaned and disinfected using the
cleaning procedures recommended by the manufacturer at the following
intervals:
(A) As necessary for respirators issued for the exclusive use of an
employee; and
(B) After each use for respirators issued to more than one
employee.
(ii) Respirators shall be inspected before each use and during
cleaning after each use;
(iii) Respirator inspections shall include:
(A) A check of respirator function, tightness of connections and
the condition of the facepiece, head straps, valves, connecting tube,
and cartridges, canisters, or filters; and
(B) A check of the rubber or elastomer parts for pliability and
signs of deterioration.
(iv) Respirators that fail to pass inspection shall be removed from
service and shall be repaired or adjusted in accordance with the
following:
(A) Repairs or adjustments to respirators are only to be made with
NIOSH-approved parts designed for the respirator by the respirator
manufacturer, and conducted by persons appropriately trained to perform
such operations;
(B) Only repairs of the type and extent covered by the
manufacturer's recommendations may be performed; and
(C) Reducing or admission valves or regulators shall be returned to
the manufacturer or given to an appropriately trained technician for
adjustment or repair.
(v) Respirators shall be stored in a manner that protects them from
contamination, damage, dust, sunlight, extreme temperatures, excessive
moisture, and damaging chemicals and prevents deformation of the
facepiece or exhalation valve.
(7) Identification of filters, cartridges, and canisters. (i)
Filters, cartridges, and canisters used in the workplace shall be
properly labeled and color-coded with the NIOSH approval label as
required by 30 CFR part 11 or 42 CFR part 84, whichever is applicable,
before they are placed into service.
(ii) The NIOSH approval label on a filter, cartridge, or canister
shall not be intentionally removed, obscured, or defaced while it is in
service in the workplace.
(8) Respiratory protection program evaluation. The employer shall
review the overall respiratory protection program at least annually,
and shall conduct inspections of the workplace as necessary to assure
that the provisions of the program are being properly implemented for
all affected employees. The review of the program shall include an
assessment of each element required under paragraph (f)(2) of this
section.
(g) Medical Surveillance--(1) General. (i) Each employer who has
any employee with occupational exposure shall provide the employee with
medical surveillance as described in this paragraph.
(ii) Each employer covered under paragraph (a), Scope, of this
section shall provide information about the signs and symptoms of
pulmonary TB, a medical history, a physical examination, TB skin
testing, medical management and follow-up and, if indicated, other
related tests and procedures, and medical removal protection if the
employee develops infectious TB, to any of his or her employees who
have an exposure incident while working in a covered work setting, even
if such employee is not categorized as having occupational exposure.
(iii) Medical surveillance provisions, including examinations,
evaluations, determinations, procedures, and medical management and
follow-up, shall be:
(A) Provided at no cost to the employee;
(B) Provided at a reasonable time and place for the employee;
(C) Performed by or under the supervision of a physician or other
licensed health care professional, as appropriate; and
(D) Provided according to recommendations of CDC current at the
time these evaluations and procedures take place, except as specified
by this paragraph (g).
(iv) Laboratory tests shall be conducted by an accredited
laboratory.
(2) Explanation of Terms. This paragraph explains the terms used in
paragraph (g).
(i) Medical history emphasizes the pulmonary system, and includes
previous exposure to M. tuberculosis, BCG vaccination, TB skin test
results, TB disease, prior and current preventive or therapeutic
treatment, current signs or symptoms of active TB disease, and factors
affecting immunocompetence;
(ii) Physical examination emphasizes the pulmonary system, signs
and symptoms of active TB disease, and factors affecting
immunocompetence;
(iii) TB skin testing, includes anergy testing if indicated, and is
only for employees whose TB skin test status is not known to be
positive. An initial 2-step protocol is to be used for each employee
who has not been previously skin tested and/or for whom a negative test
cannot be documented within the past 12 months. If the employer has
documentation that the employee has had a negative TB skin test within
the past 12 months, that test may be utilized to fulfill the skin
testing portion of this requirement. Periodic retesting shall be
performed in accordance with paragraph (g)(3) of this section.
(iv) ``Determination of the employee's ability to wear a
respirator'' is a face-to-face assessment of the health factors
affecting respirator use and the need for the annual fit test.
Note to paragraph (g)(2)(iv): A determination of the need for
the annual fit
[[Page 54289]]
test may only be performed after the required initial fit test of
the employee and cannot be used in lieu of any other required fit
tests, for example, when a different size or make of respirator is
used.
(v) ``Medical management and follow-up'' include diagnosis, and,
where appropriate, prophylaxis and treatment related to TB infection
and disease.
(vi) Other related tests and procedures include those associated
with TB infection and disease and determined to be necessary by the
physician or other licensed health care professional, as appropriate.
(vii) Medical Removal Protection is the maintenance of earnings,
seniority and other benefits specified in paragraph (g)(5) of this
section for an employee who has confirmed or suspected infectious TB or
is unable to wear a respirator.
(3) Application. (i) Each employee with occupational exposure shall
be provided with the following at the times specified:
(A) Before initial assignment to a job with occupational exposure
or within 60 days of the effective date of this standard and at least
annually thereafter: A medical history and TB skin testing, and, if
indicated, a physical examination and other related tests and
procedures;
Note to paragraph (g)(3)(i)(A): If an employee has had a medical
examination within the twelve (12) months preceding the effective
date of the standard and the employer has the documented results of
that examination, only the medical surveillance provisions required
by the standard that were not included in the examination need to be
provided. The date(s) of the previous medical examination and skin
test shall be used to determine the date(s) of the employee's next
medical examination and skin test but in no case shall the interval
between the previous examination and skin test and the next
examination and skin test exceed 12 months.
(B) When the employee has signs or symptoms of TB, either observed
or self-reported: A medical history, a physical examination, TB skin
testing, medical management and follow-up, and, if indicated, other
related tests and procedures;
(C) When an employee undergoes an exposure incident: A medical
history, TB skin testing as soon as feasible (unless there is
documented negative TB skin testing within the past 3 months), and if
the result is negative, another skin test 3 months later, medical
management and follow-up and, if indicated, a physical examination and
other related tests and procedures;
(D) When the employee has a TB skin test conversion: A medical
history, a physical examination, medical management and follow-up, and,
if indicated, other related tests;
(E) Within 30 days of the termination of employment: A TB skin
test; and
(F) At any other time the physician or other licensed health care
professional, as appropriate, deems it necessary: Any or all the
provisions of paragraph (g).
(ii) Each employee who must wear a respirator shall be provided
with the following at the times specified:
(A) Before initial assignment to a job with occupational exposure
or within 60 days of the effective date of this standard and at least
annually thereafter: A determination of the employee's ability to wear
a respirator; and
(B) When the wearer experiences unusual difficulty while being
fitted or while using a respirator: A determination of the employee's
ability to wear a respirator, including relevant components of a
medical history, and, if indicated, a physical examination and other
related tests and procedures.
(iii) An employee with negative TB skin test status shall be
provided with a TB skin test every 6 months if the employee in the
course of his or her duties:
(A) Enters an AFB isolation room or area;
(B) Performs or is present during the performance of high-hazard
procedures;
(C) Transports or is present during the transport of an individual
with suspected or confirmed infectious TB in an enclosed vehicle; or
(D) Works in an intake area where early identification procedures
are performed (e.g., emergency departments, admitting areas) in
facilities where six (6) or more individuals with confirmed infectious
TB have been encountered in the past twelve months.
(4) Additional Requirements. (i) The employer shall assure that
when the physician or other licensed health care professional, as
appropriate, determines that an employee has suspected or confirmed
infectious TB, the physician or other licensed health care
professional, as appropriate, shall notify the employer and the
employee as soon as feasible.
(ii) When the employer first identifies an individual with
confirmed infectious TB, the employer shall notify each employee who
has had an exposure incident involving that individual of his or her
exposure to confirmed TB; and
(iii) When an exposure incident results in a TB skin test
conversion, the employer shall assure that a determination is made of
the drug susceptibility of the M. tuberculosis isolate from the source,
unless the employer can demonstrate that such a determination is not
feasible.
(iv) When an exposure incident or a TB skin test conversion occurs,
the employer shall investigate and document the circumstances
surrounding the exposure incident or conversion (e.g. failure of
engineering controls or work practices and events leading to the
exposure incident) to determine if changes can be instituted to prevent
similar occurrences in the future.
(5) Medical Removal Protection. (i) Each employee with suspected or
confirmed infectious TB shall be removed from the workplace until
determined to be noninfectious.
(ii) For each employee who is removed from the workplace under
paragraph (g)(5)(i) of this section, the employer shall maintain the
total normal earnings, seniority, and all other employee rights and
benefits, including the employee's right to his or her former job
status, as if the employee had not been removed from the employee's job
or otherwise medically limited until the employee is determined to be
noninfectious or for a maximum of 18 months, whichever comes first.
(iii) For each employee who is removed from his or her job under
paragraph (f)(4)(viii), Respiratory Protection, of this section the
employer shall transfer the employee to comparable work for which the
employee is qualified or can be trained in a short period (up to 6
months), where the use of respiratory protection is not required. The
employer shall maintain the total normal earnings, seniority, and all
other employee rights and benefits. If there is no such work available,
the employer shall maintain the employee's total normal earnings,
seniority, and all other employee rights and benefits until such work
becomes available or for a maximum of 18 months, whichever comes first.
(iv) An employer's obligation to provide earnings, seniority and
other benefits to a removed employee may be reduced to the extent that
the employee receives compensation for earnings lost during the period
of removal either from a publicly or employer-funded compensation
program or from employment with another employer made possible by
virtue of the employee's removal.
(6) Information Provided to Physician or Other Licensed Health Care
Professionals. (i) Each employer shall assure that all physicians or
other licensed health care professionals responsible for making
determinations and performing procedures as part of the medical
surveillance program are
[[Page 54290]]
provided a copy of this regulation and, for those employees required to
wear respirators under this section, information regarding the type of
respiratory protection used, a description of the work effort required,
any special environmental conditions (e.g., heat, confined space
entry), additional requirements for protective clothing and equipment,
and the duration and frequency of usage of the respirator.
(ii) Each employer shall assure that the physician or other
licensed health care professional, as appropriate, who evaluates an
employee after an exposure incident is provided the following
information:
(A) A description of the exposed employee's duties as they relate
to the exposure incident;
(B) Circumstances under which the exposure incident occurred;
(C) Any diagnostic test results, including drug susceptibility
pattern or other information relating to the source of exposure which
could assist in the medical management of the employee; and
(D) All of the employee's medical records relevant to the
management of the employee, including tuberculin skin testing results.
(7) Written Opinion. (i) Each employer shall obtain and provide the
employee with a copy of the written opinion of the physician or other
licensed health care professional, as appropriate, within 15 days of
the completion of all medical evaluations required by this section.
(ii) The written opinion shall be limited to the following
information:
(A) The employee's TB skin test status;
(B) The employee's infectivity status;
(C) A statement that the employee has been informed of the results
of the medical evaluation;
(D) A statement that the employee has been told about any medical
conditions resulting from exposure to TB that require further
evaluation or treatment;
(E) Recommendations for medical removal or work restrictions and
the physician's or other licensed health care professional's opinion
regarding the employee's ability to wear a respirator.
(iii) All other findings or diagnoses shall remain confidential and
shall not be included in the written report.
(h) Communication of Hazards and Training--(1) Labels. (i) Air
systems that may reasonably be anticipated to contain aerosolized M.
tuberculosis shall be labeled ``Contaminated Air--Respiratory
Protection Required.'' The label shall be placed at all points where
ducts are accessed prior to a HEPA filter and at duct access points,
fans, and discharge outlets of non-HEPA filtered direct discharge
systems.
(ii) Clinical and research laboratory wastes that are contaminated
with M. tuberculosis and are to be decontaminated outside of the
immediate laboratory shall be labeled with the biohazard symbol or
placed in a red container(s).
(2) Signs. (i) Signs shall be posted at the entrances to:
(A) Rooms or areas used to isolate an individual with suspected or
confirmed infectious TB;
(B) Areas where procedures or services are being performed on an
individual with suspected or confirmed infectious TB; and
(C) Clinical and research laboratories where M. tuberculosis is
present.
(ii) When an AFB isolation room or area is vacated by an individual
with suspected or confirmed infectious TB, unless the individual has
been medically determined to be noninfectious, the sign shall remain
posted at the entrance until the room or area has been ventilated
according to CDC recommendations for a removal efficiency of 99.9% (see
Appendix C to this section).
(iii) Signs for AFB isolation rooms or areas, except as required in
paragraph (h)(2)(iv) of this section, shall be readily observable and
shall bear the following legend with symbol and text in white on a red
background:
BILLING CODE 4510-26-P
[GRAPHIC] [TIFF OMITTED] TP17OC97.006
BILLING CODE 4510-26-C
No Admittance Without Wearing a Type N95 or More Protective
Respirator
Note to paragraph (h)(2)(ii): Employers may include additional
information on signs provided it does not interfere with conveyance
of this message.
(iv) Signs at the entrances of clinical or research laboratories
and autopsy suites where procedures are being performed that may
generate aerosolized M. tuberculosis shall include the biohazard
symbol, name and telephone number of the laboratory director or other
designated responsible person, the infectious agent designation
Mycobacterium tuberculosis, and special requirements for entering the
laboratory or autopsy room.
(3) Information and Training. (i) Each employer shall assure that
each employee with occupational exposure participates in a training
program, which must be provided at no cost to the employee and be made
available at a reasonable time and place.
(ii) Training shall be provided as follows:
(A) Before initial assignment to tasks where occupational exposure
may occur;
(B) Within 60 days after the effective date of the standard; and
(C) At least annually thereafter, unless the employer can
demonstrate that the employee has the specific knowledge and skills
required under paragraph (h)(3)(vii) of this section. The employer must
provide re-training to the employee in any topic(s) in which specific
knowledge and skills cannot be demonstrated.
Note to paragraph (h)(3)(ii): Training in the general topics
under paragraph (h)(3)(vii) of this section which has been provided
in the past 12 months by a previous employer may be transferred to
an employee's new employer. However, the new employer must provide
training in the site-specific topics under paragraph (h)(3)(vii) in
accordance with the requirements of paragraph (h).
(iii) For employees who have received training on TB in the year
preceding the effective date of the standard, only training with
respect to the provisions of the standard that were not included in
such training need be provided. The annual retraining shall be
conducted within one year from the date of the training that occurred
before the effective date of the standard.
(iv) Annual training for each employee shall be provided within one
calendar year of the employee's previous training.
(v) The employer shall provide additional training when changes
such as modification of tasks or procedures or institution of new tasks
or procedures affect the employee's occupational exposure. The
additional training may be limited to addressing the new or modified
exposures.
(vi) Material appropriate in content and vocabulary to the
educational level, literacy, and language of employees shall be used.
(vii) The training program shall include an explanation of:
(A) The contents of this standard and the location of an accessible
copy of the regulatory text of this standard;
(B) The general epidemiology of TB, including Multidrug-Resistant
TB (MDR-TB), and the potential for exposure within the facility; the
signs and symptoms of TB, including the difference between tuberculosis
[[Page 54291]]
infection and tuberculosis disease; the modes of transmission of
tuberculosis, including the possibility of reinfection in persons with
a positive tuberculin skin test; and the personal health conditions
that increase the employee's risk of developing TB disease if infected
(e.g., HIV infection, prolonged corticosteroid therapy, other
immunocompromising conditions);
(C) The employer's exposure control plan and respiratory protection
program and the means by which the employee can review the written
plans;
(D) The tasks and other activities that may involve exposure to M.
tuberculosis;
(E) The use and limitations of methods that will prevent or reduce
exposure, including appropriate engineering controls, work practices,
respiratory protection, and site-specific control measures;
(F) Why a respirator is necessary, and the basis of selection of
the respirators used, the types of respirators used, upkeep and storage
of the respirators used, and their location and proper use, including
procedures for inspection, donning and removal, checking the fit and
seals, and wearing the respirator. This instruction shall allow
sufficient practice to enable the employee to become thoroughly
familiar with and effective in performing these tasks;
(G) The employer's medical surveillance program, including the
purpose of tuberculin skin testing, the importance of a positive or
negative skin test result, anergy testing, and the importance of
participation in the program;
(H) The procedures to follow if an exposure incident occurs,
including the method of reporting the incident and the medical
management and follow-up that the employer is required to provide, and
the benefits and risks of prophylaxis; and
(I) The procedures to follow if the employee develops signs or
symptoms of TB disease.
(viii) The person(s) conducting the training shall be knowledgeable
in the subject matter covered by the elements contained in the training
program as it relates to the workplace that the training will address.
(ix) The employer shall provide employees with an opportunity for
interactive questions and answers with the person conducting the
training session.
(i) Recordkeeping--(1) Medical Records. (i) Each employer shall
establish and maintain an accurate record for each employee with
occupational exposure, in accordance with 29 CFR 1910.1020.
(ii) This record shall include:
(A) The name, social security number, and job classification of the
employee;
(B) A copy of all results of examinations; medical testing,
including the employee's tuberculin skin test status; and follow-up
procedures;
(C) The employer's copy of the physician's or other licensed health
care professional's written opinion; and
(D) A copy of the information provided to the physician or other
licensed health care professional.
(iii) Confidentiality. The employer shall assure that employee
medical records required by paragraph (i) are:
(A) Kept confidential; and
(B) Not disclosed or reported without the employee's express
written consent to any person within or outside the workplace, except
as required by this section or as may be required by law.
(iv) The employer shall maintain the records required by paragraph
(i)(1) for at least the duration of employment plus 30 years, in
accordance with 29 CFR 1910.1020. The medical records of employees who
have worked for less than one year for the employer need not be
retained beyond the term of employment if they are provided to the
employee upon termination of employment.
(2) OSHA Illness and Injury Records. The employer shall record TB
infection or disease in accordance with 29 CFR 1904 and 29 CFR 1960, as
applicable.
(3) Training Records. (i) Training records shall include the
following information:
(A) The dates of the training sessions;
(B) The contents or a summary of the training sessions;
(C) The names and qualifications of persons conducting the
training; and
(D) The name and job classification of all persons attending the
training sessions.
(ii) Training records shall be maintained for 3 years from the date
on which the training occurred.
(4) Engineering Control Maintenance and Monitoring Records. (i)
Engineering control maintenance records shall include the following
information:
(A) Date;
(B) Equipment identification;
(C) Task performed; and
(D) Sign-off.
(ii) Performance monitoring records shall include the following
information:
(A) Date and time;
(B) Location;
(C) Parameter measured, including units when appropriate;
(D) Results of monitoring; and
(E) Sign-off.
(iii) Engineering control maintenance and monitoring records shall
be maintained for three years.
(5) Availability. (i) Employee medical records required by
paragraph (i)(1), Recordkeeping, of this section shall be provided upon
request for the examination and copying to the subject employee, to
anyone having the written consent of the subject employee, to the
Director, and to the Assistant Secretary in accordance with 29 CFR
1910.1020. OSHA Illness and Injury Records shall be accessible under
the provisions of 29 CFR 1904 and 29 CFR 1960, as applicable.
(ii) Employee training records required by paragraph (i)(3),
Recordkeeping, of this section shall be provided upon request for
examination and copying to employees, to their representatives, to the
Director, and to the Assistant Secretary.
(iii) Engineering control maintenance and monitoring records
required by paragraph (i)(4), Recordkeeping, of this section shall be
provided upon request for examination and copying to employees, their
representatives, to the Director, and to the Assistant Secretary.
(6) Transfer of Records. (i) The employer shall comply with the
requirements involving transfer of records set forth in 29 CFR
1910.1020(h) and 29 CFR 1904 and 29 CFR 1960, as applicable.
(ii) If the employer ceases to do business and there is no
successor employer to receive and retain the records for the prescribed
period, the employer shall notify the Director at least three months
before their disposal and transmit them to the Director, if required by
the Director to do so, within the three month period.
(j) Definitions. For the purposes of this section, the following
shall apply:
Acid-fast bacilli (AFB) means bacteria that retain certain dyes
after being washed in an acid solution. Most acid-fast organisms are
mycobacteria.
Accredited laboratory means a laboratory that has participated in a
quality assurance program leading to a certification of competence
administered by a governmental or private organization that tests and
certifies laboratories.
Air-purifying respirator means a respirator that is designed to
remove air contaminants from the ambient air or air surrounding the
respirator.
AFB isolation room or area includes, but is not limited to, rooms,
areas, booths, tents, or other enclosures that are maintained at
negative pressure to adjacent areas in order to control the spread of
aerosolized M. tuberculosis.
[[Page 54292]]
Anergy means the inability of a person to react to skin test
antigens (even if the person is infected with the organisms tested)
because of immunosuppression.
Assistant Secretary means the Assistant Secretary of Labor for
Occupational Safety and Health, or designated representative.
BCG (Bacille Calmette-Guerin) vaccine is a tuberculosis vaccine.
Canister or cartridge means a container with a filter, sorbent, or
catalyst, or a combination of these items, that removes specific air
contaminants from the air drawn through the container.
Clinical laboratory is a laboratory or area of a facility that
conducts routine and repetitive operations for the diagnosis of TB such
as preparing acid-fast smears and culturing sputa or other clinical
specimens for identification, typing or susceptibility testing.
Confirmed infectious tuberculosis is a disease state that has been
diagnosed by positive identification of M. tuberculosis from body fluid
or tissue through positive culture, positive gene probe, or positive
polymerase chain reaction (PCR). The disease state must be capable of
being transmitted to another individual (e.g., pulmonary or laryngeal
TB or extrapulmonary TB where the infected tissue is exposed and could
generate droplet nuclei).
Conversion means a change in tuberculin skin test results from
negative to positive, based upon current Centers for Disease Control
and Prevention (CDC) guidelines.
Director means the Director of the National Institute for
Occupational Safety and Health, U.S. Department of Health and Human
Services, or designated representative.
Disposable respirator means a respiratory protective device that
cannot be resupplied with an unused filter or cartridge and that is to
be discarded in its entirety after its useful service life has been
reached.
Exposure incident means an event in which an employee has been
exposed to an individual with confirmed infectious TB or to air
containing aerosolized M. tuberculosis without the benefit of
applicable exposure control measures required by this section.
Filter means a component used in respirators to remove solid or
liquid aerosols from the inspired air.
Fit factor means a quantitative measure of the fit of a particular
respirator on a particular individual.
High efficiency particulate air (HEPA) filter means a specialized
filter that is capable of removing 99.97% of particles greater than or
equal to 0.3 micrometer in diameter.
High hazard procedures are procedures performed on an individual
with suspected or confirmed infectious tuberculosis in which the
potential for being exposed to M. tuberculosis is increased due to the
reasonably anticipated generation of aerosolized M. tuberculosis. Such
procedures include, but are not limited to, sputum induction,
bronchoscopy, endotracheal intubation or suctioning, aerosolized
administration of pentamidine or other medications, and pulmonary
function testing. They also include autopsy, clinical, surgical and
laboratory procedures that may aerosolize M. tuberculosis.
M. tuberculosis means Mycobacterium tuberculosis, the scientific
name of the bacillus that causes tuberculosis.
Negative pressure means the relative air pressure difference
between two areas. A room that is under negative pressure has lower
pressure than adjacent areas, which keeps air from flowing out of the
room and into adjacent rooms or areas.
Negative pressure respirator means a respirator in which the air
pressure inside the facepiece is negative during inhalation with
respect to the ambient air pressure outside the respirator.
Occupational exposure means reasonably anticipated contact, that
results from the performance of an employee's duties, with an
individual with suspected or confirmed infectious TB or air that may
contain aerosolized M. tuberculosis.
Physician or other licensed health care professional means an
individual whose legally permitted scope of practice (i.e., license,
registration, or certification) allows him or her to independently
provide or be delegated the responsibility to provide some or all of
the health care services required by paragraph (g) of this section.
Powered air-purifying respirator (PAPR) means an air-purifying
respirator that uses a blower to deliver air through the air-purifying
element to the wearer's breathing zone.
Qualitative fit test means a pass/fail fit test to assess the
adequacy of respirator fit that relies on the respirator wearer's
response to a challenge agent.
Quantitative fit test means an assessment of the adequacy of
respirator fit by numerically measuring the amount of leakage into the
respirator.
Research laboratory is a laboratory that propagates and manipulates
cultures of M. tuberculosis in large volumes or high concentrations
that are in excess of those used for identification and typing
activities common to clinical laboratories.
Respirator means a device worn by an individual and intended to
provide the wearer with respiratory protection against inhalation of
airborne contaminants.
Suspected infectious tuberculosis means a potential disease state
in which an individual is known, or with reasonable diligence should be
known, by the employer to have one or more of the following conditions,
unless the individual's condition has been medically determined to
result from a cause other than TB:
(1) To be infected with M. tuberculosis and to have the signs or
symptoms of TB;
(2) To have a positive acid-fast bacilli (AFB) smear; or
(3) To have a persistent cough lasting 3 or more weeks and two or
more symptoms of active TB (e.g., bloody sputum, night sweats, weight
loss, fever, anorexia). An individual with suspected infectious TB has
neither confirmed infectious TB nor has he or she been medically
determined to be noninfectious.
Tight-fitting facepiece means a respiratory inlet covering that is
designed to form a complete seal with the face. A half-facepiece covers
the nose and mouth; a full facepiece covers the nose, mouth, and eyes.
Tuberculosis (TB) means a disease caused by M. tuberculosis.
Tuberculosis infection means a condition in which living M.
tuberculosis bacilli are present in the body without producing
clinically active disease. Although the infected individual has a
positive tuberculin skin test reaction, he or she may have no symptoms
related to the infection and may not be capable of transmitting the
disease.
Tuberculosis disease is a condition in which living M. tuberculosis
bacilli are present in the body, producing clinical illness. The
individual may or may not be infectious.
Tuberculin skin test means a method used to evaluate the likelihood
that a person is infected with M. tuberculosis. The method utilizes an
intradermal injection of tuberculin antigen with subsequent measurement
of the reaction induration. It is also referred to as a PPD skin test.
Two-step testing is a baseline skin testing procedure used to
identify a boosted skin test reaction from that of a new infection. The
procedure involves placing a second skin test 1 to 3 weeks after an
initial negative test. A positive reaction on the second test indicates
a boosted reaction.
[[Page 54293]]
(k) Dates.--(1) Effective Date. The standard shall become effective
on [insert date 90 days after publication of final rule in the Federal
Register].
(2) Start-up dates. (i) Exposure control. The exposure control
provisions required by paragraph (c) of this section shall take effect
on [insert date 30 days after effective date of final rule].
(ii) The Information and Training provisions required under
paragraph (h)(3), the Medical surveillance provisions required by
paragraph (g), and the Recordkeeping provisions required by paragraph
(i) of this section shall take effect on [insert date 60 days after
effective date of final rule].
(iii) Work practices and Engineering controls. The work practice
and engineering control provisions required by paragraph (d) of this
section shall take effect on [insert date 90 days after effective date
of final rule]. For businesses with fewer than 20 employees,
engineering controls required by paragraph (d) of this section shall
take effect [insert 270 days after effective date of final rule]. Work
practice controls that are directly related to engineering controls
being installed in accordance with this paragraph shall be implemented
as soon as those engineering controls are implemented.
(iv) Respiratory protection. Respiratory protection provisions
required by paragraph (f) of this section shall take effect on [insert
date 90 days after effective date of final rule].
(v) Labels and signs. The labels and signs provisions required by
paragraphs (h)(1) and (h)(2) of this section shall take effect on
[insert date 90 days after effective date of final rule].
(vi) Clinical and research laboratories. The additional
requirements for Clinical and Research Laboratories contained in
paragraphs (e)(1) through (e)(3) shall take effect on [insert date 90
days after effective date of final rule].
Appendix A to Sec. 1910.1035--Provisions for Employers Claiming
Reduced Responsibilities Under Paragraph (b), Application
(Mandatory)
(c) Exposure Control
Paragraph (c)(1)(i & ii) Exposure Determination
(c)(2)(i) Written Exposure Control Plan with the following
elements:
(c)(2)(i)(A) The exposure determination
(c)(2)(i)(B) Procedures for providing information to employees
about individuals identified with suspected or confirmed infectious
TB or air that may reasonably be anticipated to contain aerosolized
M. tuberculosis
(c)(2)(i)(C) Procedures for reporting an exposure incident
(c)(2)(ii) Procedures for identifying, masking or segregating and
transferring individuals with suspected or confirmed infectious TB
(c)(2)(vi) Documentation of the number of individuals with
confirmed infectious TB encountered in the past 12 months
(c)(2)(vii) (A-C) Accessible exposure control plan, reviewed
annually and updated as necessary, and made available to the
Assistant Secretary and Director
(d) Work Practice Procedures and Engineering Controls
(d)(1) Use of work practices to eliminate or minimize employee
exposure
(d)(2) Implementation of the work practice procedures in the
exposure control plan
(d)(3)(i) Identification and masking or segregating of individuals
with suspected or confirmed infectious TB
(d)(3)(ii) Temporary isolation of individuals who cannot be
transferred within 5 hours
(d)(5)(i-vii) Engineering controls if temporary isolation is used
(d)(6) Provide information about TB hazards to temporary or
personnel who may incur occupational exposure
(g) Medical Surveillance
(g)(1)(i-iv) Medical surveillance program for each employee with
occupational exposure or who has an exposure incident in one of the
covered work settings, at no cost, at a reasonable time, by a
physician or other licensed health care professional, according to
current recommendations of the CDC and with laboratory tests
conducted by an accredited laboratory
(g)(2)(i, ii, iii, v, vi & vii) Explanation of terms: Medical
history, Physical examination, tuberculin skin testing, medical
management and follow-up, medical removal protection, and other
related tests and procedures
(g)(3)(i)(A) Initial TB skin testing and medical history (NOTE:
Annual skin testing and medical histories are not required)
(g)(3)(i)(B) Medical history, TB skin testing and follow-up for
employees who develop signs or symptoms of TB
(g)(3)(i)(C) Medical history, TB skin testing and medical
management and follow-up of employees after an exposure incident
(g)(4)(i) Notification of employee and employer as soon as feasible
about infectious TB disease status of the employee
(g)(4)(ii) Notification of employees about previously unidentified
individuals with infectious TB
(g)(4)(iii) Determination of drug susceptibility of M. tuberculosis
source after an exposure incident
(g)(4)(iv) Investigations of exposure incidents and TB skin test
conversions
(g)(5)(i, ii & iv) Medical removal and protection of benefits for
individuals with infectious TB
(g)(6)(i & ii) Information provided to the physician or other
licensed health care professional
(g)(7)(i-iii) Physician or other licensed health care
professional's written opinion
(h) Communication of Hazards and Training
(h)(1)(i) If temporary isolation is used, label air systems that
may reasonably be anticipated to contain aerosolized M. tuberculosis
(h)(2)(i)(A) If temporary isolation is used, post signs at entrance
to temporary isolation
(h)(2)(ii) When temporary isolation room or area is vacated by an
individual with suspected or confirmed infectious TB, ventilate for
an appropriate period
(h)(2)(iii) Signs for temporary isolation rooms or areas must have
a stop sign with the legend ``No Admittance Without Wearing a Type
N95 or More Protective Respirator''
(h)(3)(i-viii) Annual training with specified elements for
employees with occupational exposure
(i) Recordkeeping
(i)(1)(i-iv) Medical Records
(i)(2) OSHA Illness and Injury Records
(i)(3)(i & ii) Training Records
(i)(4)(i-iii) If temporary isolation is used, engineering control
maintenance records
(i)(5)(i & ii) Availability of medical and training records
(i)(6)(i & ii) Transfer of records
(k) Dates
(k)(1) Effective date
(k)(2)(i, ii & iii) Start up dates for exposure control, medical
surveillance, information and training, recordkeeping, and work
practices and engineering controls
Appendix B to Sec. 1910.1035--Fit Testing Procedures (Mandatory)
Part I. Approved Fit Test Protocols
A. Fit Testing Procedures
The employer shall conduct fit testing using the following
procedures. These provisions apply to both QLFT and QNFT.
1. The test subject shall be allowed to pick the most acceptable
respirator from a selection of respirators of various sizes and
models.
2. Prior to the selection process, the test subject shall be
shown how to put on a respirator, how it should be positioned on the
face, how to set strap tension and how to determine an acceptable
fit. A mirror shall be available to assist the subject in evaluating
the fit and positioning the respirator. This instruction may not
constitute the subject's formal training on respirator use, as it is
only a review.
3. The test subject shall be informed that he or she is being
asked to select the respirator that provides the most acceptable
fit. Each respirator represents a different size and shape, and if
fitted and used properly, will provide adequate protection.
4. The test subject shall be instructed to hold each chosen
facepiece up to the face and eliminate those that obviously do not
give an acceptable fit.
5. The more acceptable facepieces are noted; the most acceptable
mask is donned
[[Page 54294]]
and worn at least five minutes to assess acceptability. Assistance
in assessing acceptability can be given by discussing the points in
item 6 below. If the test subject is not familiar with using a
particular respirator, the test subject shall be directed to don the
mask several times and to adjust the straps each time to become
adept at setting proper tension on the straps.
6. Assessment of acceptability shall include reviewing the
following points with the test subject and allowing the test subject
adequate time to determine the acceptability of the respirator:
(a) Position of the mask on the nose,
(b) Room for eye protection,
(c) Room to talk;
(d) Position of mask on face and cheeks.
7. The following criteria shall be used to help determine the
adequacy of the respirator fit:
(a) Chin properly placed;
(b) Adequate strap tension, not overly tightened;
(c) Fit across nose bridge;
(d) Respirator of proper size to span distance from nose to
chin;
(e) Tendency of respirator to slip;
(f) Self-observation in mirror to evaluate fit and respirator
position.
8. The test subject shall conduct the negative and positive
pressure fit checks as described in this appendix or other fit check
procedures recommended by the respirator manufacturer providing
equivalent protection to the procedures in this appendix. Before
conducting the negative or positive pressure fit checks, the subject
shall be told to seat the mask on the face by moving the head from
side-to-side and up and down slowly while taking in a few slow deep
breaths. Another facepiece shall be selected and retested if the
test subject fails the fit check tests.
9. The test shall not be conducted if there is any hair growth
between the skin and the facepiece sealing surface, such as stubble
beard growth, beard, mustache or sideburns that cross the respirator
sealing surface. Any type of apparel which interferes with a
satisfactory fit shall be altered or removed.
10. If a test subject exhibits difficulty in breathing during
the tests, she or he shall be referred to a physician or other
licensed health care professional, as appropriate, to determine
whether the test subject can wear a respirator while performing her
or his duties.
11. If the employee finds the fit of the respirator
unacceptable, the test subject shall be given the opportunity to
select a different respirator and to be retested.
12. Exercise regimen. Prior to the commencement of the fit test,
the test subject shall be given a description of the fit test and
the test subject's responsibilities during the test procedure. The
description of the process shall include a description of the test
exercises that the subject will be performing. The respirator to be
tested shall be worn for at least 5 minutes before the start of the
fit test.
13. Test Exercises. The test subject shall perform exercises, in
the test environment, while wearing any applicable safety equipment
that may be worn during actual respirator use which could interfere
with fit, in the manner described below:
(a) Normal breathing. In a normal standing position, without
talking, the subject shall breathe normally.
(b) Deep breathing. In a normal standing position, the subject
shall breathe slowly and deeply, taking caution so as to not
hyperventilate.
(c) Turning head side to side. Standing in place, the subject
shall slowly turn his or her head from side to side between the
extreme positions on each side. The head shall be held at each
extreme momentarily so the subject can inhale at each side.
(d) Moving head up and down. Standing in place, the subject
shall slowly move his/her head up and down. The subject shall be
instructed to inhale in the up position (i.e., when looking toward
the ceiling).
(e) Talking. The subject shall talk out loud slowly and loud
enough so as to be heard clearly by the test conductor. The subject
can read from a prepared text such as the Rainbow Passage, count
backward from 100, or recite a memorized poem or song.
Rainbow Passage
When the sunlight strikes raindrops in the air, they act like a
prism and form a rainbow. The rainbow is a division of white light
into many beautiful colors. These take the shape of a long round
arch, with its path high above, and its two ends apparently beyond
the horizon. There is, according to legend, a boiling pot of gold at
one end. People look, but no one ever finds it. When a man looks for
something beyond reach, his friends say he is looking for the pot of
gold at the end of the rainbow.
(f) Grimace. The test subject shall grimace by smiling or
frowning. (Only for QNFT testing, not performed for QLFT)
(g) Bending over. The test subject shall bend at the waist as if
he/she were to touch his/her toes. Jogging in place shall be
substituted for this exercise in those test environments such as
shroud type QNFT units which prohibit bending at the waist.
(h) Normal breathing. Same as exercise (a). Each test exercise
shall be performed for one minute except for the grimace exercise
which shall be performed for 15 seconds.
The test subject shall be questioned by the test conductor
regarding the acceptability of the respirator upon completion of the
protocol. If it has become unacceptable, another model of respirator
shall be tried.
B. Qualitative Fit Test (QLFT) Protocols
1. General
(a) The employer shall assign specific individuals who shall
assume full responsibility for implementing the respirator
qualitative fit test program.
(b) The employer shall ensure that persons administering QLFT
are able to prepare test solutions, calibrate equipment and perform
tests properly, recognize invalid tests, and assure that test
equipment is in proper working order.
(c) The employer shall assure that QLFT equipment is kept clean
and well maintained so as to operate within the parameters for which
it was designed.
2. Isoamyl Acetate Protocol
Note: This protocol is not appropriate, by itself, for fit
testing particulate respirators. If chosen for use in fit testing
particulate respirators, the respirator must be equipped with an
organic vapor cartridge, provided the employee will be using the
same facepiece in the work setting except that it will be equipped
with particulate filters.
(a) Odor threshold screening. The odor threshold screening test,
performed without wearing a respirator, is intended to determine if
the individual tested can detect the odor of isoamyl acetate.
(1) Three 1 liter glass jars with metal lids are required.
(2) Odor free water (e.g. distilled or spring water) at
approximately 25 degrees C shall be used for the solutions.
(3) The isoamyl acetate (IAA) (also known at isopentyl acetate)
stock solution is prepared by adding 1 cc of pure IAA to 800 cc of
odor free water in a 1 liter jar and shaking for 30 seconds. A new
solution shall be prepared at least weekly.
(4) The screening test shall be conducted in a room separate
from the room used for actual fit testing. The two rooms shall be
well ventilated to prevent the odor of IAA from becoming evident in
the general room air where testing takes place.
(5) The odor test solution is prepared in a second jar by
placing 0.4 cc of the stock solution into 500 cc of odor free water
using a clean dropper or pipette. The solution shall be shaken for
30 seconds and allowed to stand for two to three minutes so that the
IAA concentration above the liquid may reach equilibrium. This
solution shall be used for only one day.
(6) A test blank shall be prepared in a third jar by adding 500
cc of odor free water.
(7) The odor test and test blank jars shall be labeled 1 and 2
for jar identification. Labels shall be placed on the lids so they
can be periodically peeled off and switched to maintain the
integrity of the test.
(8) The following instruction shall be typed on a card and
placed on the table in front of the two test jars (i.e., 1 and 2):
The purpose of this test is to determine if you can smell banana oil
at a low concentration. The two bottles in front of you contain
water. One of these bottles also contains a small amount of banana
oil. Be sure the covers are on tight, then shake each bottle for two
seconds. Unscrew the lid of each bottle, one at a time, and sniff at
the mouth of the bottle. Indicate to the test conductor which bottle
contains banana oil.
(9) The mixtures used in the IAA odor detection test shall be
prepared in an area separate from where the test is performed, in
order to prevent olfactory fatigue in the subject.
(10) If the test subject is unable to correctly identify the jar
containing the odor test solution, the IAA qualitative fit test
shall not be performed.
(11) If the test subject correctly identifies the jar containing
the odor test solution, the test subject may proceed to respirator
selection and fit testing.
(b) Isoamyl acetate fit test. (1) The fit test chamber shall be
similar to a clear 55-gallon drum liner suspended inverted over a 2-
foot
[[Page 54295]]
diameter frame so that the top of the chamber is about 6 inches
above the test subject's head. The inside top center of the chamber
shall have a small hook attached.
(2) Each respirator used for the fitting and fit testing shall
be equipped with organic vapor cartridges or offer protection
against organic vapors.
(3) After selecting, donning, and properly adjusting a
respirator, the test subject shall wear it to the fit testing room.
This room shall be separate from the room used for odor threshold
screening and respirator selection, and shall be well ventilated, as
by an exhaust fan or lab hood, to prevent the test medium that is
not contained will be removed from the general room air.
(4) A copy of the test exercises and any prepared text from
which the subject is to read shall be taped to the inside of the
test chamber.
(5) Upon entering the test chamber, the test subject shall be
given a 6-inch by 5-inch piece of paper towel, or other porous,
absorbent, single-ply material, folded in half and wetted with 0.75
cc of pure IAA. The test subject shall hang the wet towel on the
hook at the top of the chamber.
(6) Allow two minutes for the IAA test concentration to
stabilize before starting the fit test exercises. This would be an
appropriate time to talk with the test subject; to explain the fit
test, the importance of his/her cooperation, and the purpose for the
test exercises; or to demonstrate some of the exercises.
(7) If at any time during the test, the subject detects the
banana like odor of IAA, the test is failed. The subject shall
quickly exit from the test chamber and leave the test area to avoid
olfactory fatigue.
(8) If the test is failed, the subject shall return to the
selection room and remove the respirator. The test subject shall
repeat the odor sensitivity test, select and put on another
respirator, return to the test area and again begin the fit test
procedure described in (1) through (7) above. The process continues
until a respirator that fits well has been found. Should the odor
sensitivity test be failed, the subject shall wait about 5 minutes
before retesting. Odor sensitivity will usually have returned by
this time.
(9) When the subject wearing the respirator passes the test, its
efficiency shall be demonstrated for the subject by having the
subject break the face seal and take a breath before exiting the
chamber.
(10) When the test subject leaves the chamber, the subject shall
remove the saturated towel and return it to the person conducting
the test, so there is no significant IAA concentration buildup in
the chamber during subsequent tests. The used towels shall be kept
in a self sealing bag to keep the test area from being contaminated.
3. Saccharin Solution Aerosol Protocol
The entire screening and testing procedure shall be explained to
the test subject prior to the conduct of the screening test.
(a) Taste threshold screening. The saccharin taste threshold
screening, performed without wearing a respirator, is intended to
determine whether the individual being tested can detect the taste
of saccharin.
(1) During threshold screening as well as during fit testing,
subjects shall wear an enclosure about the head and shoulders that
is approximately 12 inches in diameter by 14 inches tall with at
least the front portion clear and that allows free movements of the
head when a respirator is worn. An enclosure substantially similar
to the 3M hood assembly, parts # FT 14 and # FT 15 combined, is
adequate.
(2) The test enclosure shall have a \3/4\-inch hole in front of
the test subject's nose and mouth area to accommodate the nebulizer
nozzle.
(3) The test subject shall don the test enclosure. Throughout
the threshold screening test, the test subject shall breathe through
his/her slightly open mouth with tongue extended.
(4) Using a nebulizer device such as the DeVilbiss Model 40
Inhalation Medication Nebulizer or equivalent, the test conductor
shall spray the threshold check solution into the enclosure. This
nebulizer shall be clearly marked to distinguish it from the fit
test solution nebulizer.
(5) The threshold check solution consists of 0.83 grams of
sodium saccharin USP in 100 ml of warm water. It can be prepared by
putting 1 ml of the fit test solution (see (b)(5) below) in 100 ml
of distilled water.
(6) To produce the aerosol, the nebulizer bulb is firmly
squeezed so that it collapses completely, and is then released and
allowed to fully expand.
(7) Ten squeezes are repeated rapidly and then the test subject
is asked whether the saccharin can be tasted.
(8) If the first response is negative, ten more squeezes are
repeated rapidly and the test subject is again asked whether the
saccharin is tasted.
(9) If the second response is negative, ten more squeezes are
repeated rapidly and the test subject is again asked whether the
saccharin is tasted.
(10) The test conductor will take note of the number of squeezes
required to solicit a taste response.
(11) If the saccharin is not tasted after 30 squeezes (step 10),
the test subject may not perform the saccharin fit test.
(12) If a taste response is elicited, the test subject shall be
asked to take note of the taste for reference in the fit test.
(13) Correct use of the nebulizer means that approximately 1 ml
of liquid is used at a time in the nebulizer body.
(14) The nebulizer shall be thoroughly rinsed in water, shaken
dry, and refilled at least each morning and afternoon or at least
every four hours.
(b) Saccharin solution aerosol fit test procedure.
(1) The test subject may not eat, drink (except plain water),
smoke, or chew gum for 15 minutes before the test.
(2) The fit test uses the same enclosure described in (a) above.
(3) The test subject shall don the enclosure while wearing the
respirator selected in section I.A. above. The respirator shall be
properly adjusted and equipped with a particulate filter(s).
(4) A second nebulizer device such as the DeVilbiss Model 40
Inhalation Medication Nebulizer or equivalent is used to spray the
fit test solution into the enclosure. This nebulizer shall be
clearly marked to distinguish it from the screening test solution
nebulizer.
(5) The fit test solution is prepared by adding 83 grams of
sodium saccharin to 100 ml of warm water.
(6) As before, the test subject shall breathe through the
slightly open mouth with tongue extended.
(7) The nebulizer is inserted into the hole in the front of the
enclosure and the fit test solution is sprayed into the enclosure
using the same number of squeezes required to elicit a taste
response in the screening test. A minimum of 10 squeezes is
required.
(8) After generating the aerosol the test subject shall be
instructed to perform the exercises in section I. A. 13 above.
(9) Every 30 seconds the aerosol concentration shall be
replenished using one half the number of squeezes as initially.
(10) The test subject shall indicate to the test conductor if at
any time during the fit test the taste of saccharin is detected.
(11) If the taste of saccharin is detected, the fit is deemed
unsatisfactory and a different respirator shall be tried.
4. Bitrex (Denatonium benzoate) Solution Aerosol Qualitative Fit Test
Protocol
The Bitrex (Denatonium benzoate) solution aerosol QLFT protocol
uses the published saccharin test protocol because of its current
acceptance and past validation. Bitrex is routinely used as a taste
aversion agent in household liquids which children should not be
drinking and is endorsed by the American Medical Association, the
National Safety Council, and the American Association of Poison
Control Centers. The entire screening and testing procedure shall be
explained to the test subject prior to the conduct of the screening
test.
(a) Taste Threshold Screening. The Bitrex taste threshold
screening, performed without wearing a respirator, is intended to
determine whether the individual being tested can detect the taste
of Bitrex.
(1) During threshold screening as well as during fit testing,
subjects shall wear an enclosure about the head and shoulders that
is approximately 12 inches (30.5 cm) in diameter by 14 inches (35.6
cm) tall. The front portion of the enclosure shall be clear from the
respirator and allow free movement of the head when a respirator is
worn. An enclosure substantially similar to the 3M hood assembly,
parts # 14 and # 15 combined, is adequate.
(2) The test enclosure shall have a \3/4\ inch (1.9 cm) hole in
front of the test subject's nose and mouth area to accommodate the
nebulizer nozzle.
(3) The test subject shall don the test enclosure. Throughout
the threshold screening test, the test subject shall breathe through
his or her slightly open mouth with tongue extended.
(4) Using a nebulizer device such as a DeVilbiss Model 40
Inhalation Medication Nebulizer or equivalent, the test conductor
shall spray the threshold check solution into the enclosure. This
nebulizer shall be clearly marked to distinguish it from the fit
test solution nebulizer.
[[Page 54296]]
(5) The threshold check solution consists of 13.5 milligrams of
Bitrex in 100 ml of 5% NaCl solution in distilled water.
(6) To produce the aerosol, the nebulizer bulb is firmly
squeezed so that the bulb collapses completely, and is then released
and allowed to fully expand.
(7) Ten squeezes are repeated rapidly and then the test subject
is asked whether the Bitrex can be tasted.
(8) If the first response is negative, ten more squeezes are
repeated rapidly and the test subject is again asked whether the
Bitrex is tasted.
(9) If the second response is negative, ten more squeezes are
repeated rapidly and the test subject is again asked whether the
Bitrex is tasted.
(10) The test conductor will take note of the number of squeezes
required to solicit a taste response.
(11) If the Bitrex is not tasted after 30 squeezes (step 10),
the test subject may not perform the Bitrex fit test.
(12) If a taste response is elicited, the test subject shall be
asked to take note of the taste for reference in the fit test.
(13) Correct use of the nebulizer means that approximately 1 ml
of liquid is used at a time in the nebulizer body.
(14) The nebulizer shall be thoroughly rinsed in water, shaken
to dry, and refilled at least each morning and afternoon or at least
every four hours.
(b) Bitrex solution aerosol fit test procedure.
(1) The test subject may not eat, drink (except plain water),
smoke, or chew gum for 15 minutes before the test.
(2) The fit test uses the same enclosure described in (a) above.
(3) The test subject shall don the enclosure while wearing the
respirator selected in section I.A. of this appendix. The respirator
shall be properly adjusted and equipped with a particulate
filter(s).
(4) A second nebulizer device such as a DeVilbiss Model 40
Inhalation Medication Nebulizer or equivalent is used to spray the
fit test solution into the enclosure. This nebulizer shall be
clearly marked to distinguish it from the screening test solution
nebulizer.
(5) The fit test solution is prepared by adding 337.5 mg of
Bitrex in 200 ml of a 5% solution of NaCl in warm water.
(6) As before, the test subject shall breathe through his or her
slightly open mouth with tongue extended.
(7) The nebulizer is inserted into the hole in the front of the
enclosure and the fit test solution is sprayed into the enclosure
using the same number of squeezes required to elicit a taste
response in the screening test.
(8) After generating the aerosol the test subject shall be
instructed to perform the exercises in section I.A.13 of this
appendix.
(9) Every 30 seconds the aerosol concentration shall be
replenished using half the number of squeezes as initially.
(10) The test subject shall indicate to the test conductor if at
any time during the fit test the taste of Bitrex is detected.
(11) If the taste of Bitrex is detected, the fit is deemed
unsatisfactory and a different respirator shall be tried.
5. Irritant Fume Protocol
(a) The respirator to be tested shall be equipped with high-
efficiency particulate filters (i.e., HEPA, N100, R100, or P100) .
(b) No form of test enclosure or hood for the test subject shall
be used.
(c) The test subject shall be allowed to smell a weak
concentration of the irritant smoke before the respirator is donned
to become familiar with its irritating properties.
(d) Break both ends of a ventilation smoke tube containing
stannic chloride. Attach one end of the smoke tube to an aspirator
squeeze bulb and cover the other end with a short piece of tubing to
prevent potential injury from the jagged end of the smoke tube.
(e) Advise the test subject that the smoke can be irritating to
the eyes and instruct the subject to keep his or her eyes closed
while the test is performed.
(f) The test conductor shall direct the stream of irritant smoke
from the smoke tube towards the face seal area of the test subject
beginning at least 12 inches from the facepiece and gradually moving
to within one inch, moving around the whole perimeter of the mask.
(g) The exercises identified in section I.A. 13 above shall be
performed by the test subject while the respirator seal is being
challenged by the smoke.
(h) Each test subject passing the smoke test without evidence of
a response (involuntary cough) shall be given a sensitivity check of
the smoke from the same tube once the respirator has been removed to
determine whether he or she reacts to the smoke. Failure to evoke a
response shall void the fit test.
(i) The fit test shall be performed in a location with exhaust
ventilation sufficient to prevent general contamination of the
testing area by the test agent.
C. Quantitative Fit Test (QNFT) Protocols
The following quantitative fit testing procedures have been
demonstrated to be acceptable:
(1) Quantitative fit testing using a non-hazardous challenge
aerosol (such as corn oil or sodium chloride) generated in a test
chamber, and employing instrumentation to quantify the fit of the
respirator.
(2) Quantitative fit testing using ambient aerosol as the
challenge agent and appropriate instrumentation (condensation nuclei
counter) to quantify the respirator fit.
(3) Quantitative fit testing using controlled negative pressure
and appropriate instrumentation to measure the volumetric leak rate
of a facepiece to quantify the respirator fit.
1. General
(a) The employer shall assign specific individuals who shall
assume full responsibility for implementing the respirator
quantitative fit test program.
(b) The employer shall ensure that persons administering QNFT
are able to calibrate equipment and perform tests properly,
recognize invalid tests, calculate fit factors properly and assure
that test equipment is in proper working order.
(c) The employer shall assure that QNFT equipment is kept clean,
maintained and calibrated according to the manufacturer's
instructions so as to operate at the parameters for which it was
designed.
2. Generated Aerosol Protocol
(a) Apparatus. (1) Instrumentation. Aerosol generation,
dilution, and measurement systems using particulates (corn oil or
sodium chloride) or gases or vapors as test aerosols shall be used
for quantitative fit testing.
(2) Test chamber. The test chamber shall be large enough to
permit all test subjects to perform freely all required exercises
without disturbing the challenge agent concentration or the
measurement apparatus. The test chamber shall be equipped and
constructed so that the challenge agent is effectively isolated from
the ambient air, yet uniform in concentration throughout the
chamber.
(3) When testing air-purifying respirators, the normal filter or
cartridge element shall be replaced with a high-efficiency
particulate filter (i.e., HEPA, N100, R100, P100) supplied by the
same manufacturer in the case of particulate QNFT aerosols or a
sorbent offering contaminant penetration protection equivalent to
high-efficiency filters where the QNFT test agent is a gas or vapor.
(4) The sampling instrument shall be selected so that a computer
record or strip chart record may be made of the test showing the
rise and fall of the challenge agent concentration with each
inspiration and expiration at fit factors of at least 2,000.
Integrators or computers that integrate the amount of test agent
penetration leakage into the respirator for each exercise may be
used, provided a record of the readings is made.
(5) The combination of substitute air-purifying elements,
challenge agent and challenge agent concentration shall be such that
the test subject is not exposed in excess of an established exposure
limit for the challenge agent at any time during the testing process
based upon the length of the exposure and the exposure limit
duration.
(6) The sampling port on the test specimen respirator shall be
placed and constructed so that no leakage occurs around the port
(e.g. where the respirator is probed), a free air flow is allowed
into the sampling line at all times and so that there is no
interference with the fit or performance of the respirator. The in-
mask sampling device (probe) shall be designed and used so that the
air sample is drawn from the breathing zone of the test subject,
midway between the nose and mouth and with the probe extending into
the facepiece cavity at least \1/4\ inch.
(7) The test set-up shall permit the person administering the
test to observe the test subject inside the chamber during the test.
(8) The equipment generating the challenge atmosphere shall
maintain the concentration of challenge agent constant to within a
10 percent variation for the duration of the test.
(9) The time lag (interval between an event and the recording of
the event on the strip chart or computer or integrator) shall be
kept to a minimum. There shall be a clear association between the
occurrence of an event and its being recorded.
(10) The sampling line tubing for the test chamber atmosphere
and for the respirator sampling port shall be of equal diameter and
[[Page 54297]]
of the same material. The length of the two lines shall be equal.
(11) The exhaust flow from the test chamber shall pass through
an appropriate filter (i.e., high efficiency or sorbent) before
release.
(12) When sodium chloride aerosol is used, the relative humidity
inside the test chamber shall not exceed 50 percent.
(13) The limitations of instrument detection shall be taken into
account when determining the fit factor.
(14) Test respirators shall be maintained in proper working
order and inspected for deficiencies such as cracks, missing valves
and gaskets, etc.
(b) Procedural Requirements. (1) When performing the initial
positive or negative pressure fit check, the sampling line shall be
crimped closed in order to avoid air pressure leakage during either
of these fit checks.
(2) An abbreviated screening QLFT test may be utilized in order
to quickly identify poor fitting respirators which passed the
positive and/or negative pressure test and thus reduce the amount of
QNFT time. The use of the CNC QNFT instrument in the count mode is
another method that can be used to obtain a quick estimate of fit
and eliminate poor fitting respirators before going on to perform a
full QNFT.
(3) A reasonably stable challenge agent concentration shall be
measured in the test chamber prior to testing. For canopy or shower
curtain type of test units the determination of the challenge agent
stability may be established after the test subject has entered the
test environment.
(4) Immediately after the subject enters the test chamber, the
challenge agent concentration inside the respirator shall be
measured to ensure that the peak penetration does not exceed 5
percent for a half mask or 1 percent for a full facepiece
respirator.
(5) A stable challenge concentration shall be obtained prior to
the actual start of testing.
(6) Respirator restraining straps shall not be over tightened
for testing. The straps shall be adjusted by the wearer without
assistance from other persons to give a reasonable fit typical of
normal use.
(7) The test shall be terminated whenever any single peak
penetration exceeds 5 percent for half masks and 1 percent for full
facepiece respirators. The test subject shall be refitted and
retested.
(c) Calculation of fit factors. (1) The fit factor shall be
determined for the quantitative fit test by taking the ratio of the
average chamber concentration to the concentration measured inside
the respirator for each test exercise except the grimace exercise.
(2) The average test chamber concentration shall be calculated
as the arithmetic average of the concentration measured before and
after each test (i.e., 8 exercises) or the arithmetic average of the
concentration measured before and after each exercise or the true
average measured continuously during the respirator sample.
(3) The concentration of the challenge agent inside the
respirator shall be determined by one of the following methods:
(i) Average peak penetration method, which is the method of
determining test agent penetration into the respirator utilizing a
strip chart recorder, integrator, or computer. The agent penetration
is determined by an average of the peak heights on the graph or by
computer integration, for each exercise except the grimace exercise.
Integrators or computers that calculate the actual test agent
penetration into the respirator for each exercise also meet the
requirements of the average peak penetration method.
(ii) Maximum peak penetration method means the method of
determining test agent penetration in the respirator as determined
by strip chart recordings of the test. The highest peak penetration
for a given exercise is taken to be representative of average
penetration into the respirator for that exercise.
(iii) Integration by calculation of the area under the
individual peak for each exercise except the grimace exercise is
another method. This includes computerized integration.
(iv) The calculation of the overall fit factor using individual
exercise fit factors involves first converting the exercise fit
factors to penetration values, determining the average, and then
converting that result back to a fit factor is also appropriate.
This procedure is described in the following equation:
[GRAPHIC] [TIFF OMITTED] TP17OC97.007
Where ff1, ff2, ff3, etc. are
the fit factors for exercise 1,2,3, etc.
(4) The test subject shall not be permitted to wear a half mask
or quarter facepiece respirator unless a minimum fit factor of 100
is obtained, or a full facepiece respirator unless a minimum fit
factor of 500 is obtained.
(5) Filters used for quantitative fit testing shall be replaced
whenever increased breathing resistance is encountered, or when the
test agent has altered the integrity of the filter media. Organic
vapor cartridges/canisters shall be replaced if there is any
indication of breakthrough by a test agent.
3. Ambient Aerosol Condensation Nuclei Counter (CNC) Protocol
The ambient aerosol condensation nuclei counter (CNC)
quantitative fit testing (PortacountTM) protocol
quantitatively fit tests respirators with the use of a probe. The
probed respirator is only used for quantitative fit tests. A probed
respirator has a special sampling device, installed on the
respirator, that allows the probe to sample the air from inside the
mask. A probed respirator is required for each make, model, and size
that is intended to be used and can be obtained from the respirator
manufacturer or distributor. The CNC instrument manufacturer TSI
also provides probe attachments (TSI sampling adapters) that permit
fit testing in an employee's own respirator. A minimum fit factor
pass level of 100 is necessary for a half-mask respirator and a
minimum fit factor of at least 500 is required for a full facepiece
respirator. The Agency does not recommend the use of homemade
sampling adapters. The entire screening and testing procedure shall
be explained to the test subject prior to the conduct of the
screening test.
(a) Portacount Fit Test Requirements.
(1) Check the respirator to make sure the respirator is fitted
with a high efficiency filter (i.e., HEPA, N100, R100, P100) and
that the sampling probe and line are properly attached to the
facepiece.
(2) Instruct the person to be tested to don the respirator
several minutes before the fit test starts. This purges the
particles inside the respirator and permits the wearer to make
certain the respirator is comfortable. This individual should have
already been trained on how to wear the respirator properly.
(3) Check the following conditions for the adequacy of the
respirator fit: Chin properly placed; Adequate strap tension, not
overly tightened; Fit across nose bridge; Respirator of proper size
to span distance from nose to chin; Tendencies for the respirator to
slip; Self-observation in a mirror to evaluate fit; and respirator
position.
(4) Have the person wearing the respirator do a fit check. If
leakage is detected, determine the cause. If leakage is from a
poorly fitting facepiece, try another size of the same type of
respirator.
(5) Follow the instructions for operating the Portacount and
proceed with the test.
(b) Portacount Test Exercises--(1) Normal breathing. In a normal
standing position, without talking, the subject shall breathe
normally for 1 minute.
(2) Deep breathing. In a normal standing position, the subject
shall breathe slowly and deeply for 1 minute, taking caution so as
not to hyperventilate.
(3) Turning head side to side. Standing in place, the subject
shall slowly turn his or her head from side to side between the
extreme positions on each side for 1 minute. The head shall be held
at each extreme momentarily so the subject can inhale at each side.
(4) Moving head up and down. Standing in place, the subject
shall slowly move his or her head up and down for 1 minute. The
subject shall be instructed to inhale in the up position (i.e., when
looking toward the ceiling).
(5) Talking. The subject shall talk out loud slowly and loud
enough so as to be heard clearly by the test conductor. The subject
can read from a prepared text such as the Rainbow Passage, count
backward from 100, or recite a memorized poem or song for 1 minute.
[[Page 54298]]
(6) Grimace. The test subject shall grimace by smiling or
frowning for 15 seconds.
(7) Bending Over. The test subject shall bend at the waist as if
he or she were to touch his or her toes for 1 minute. Jogging in
place shall be substituted for this exercise in those test
environments such as shroud type QNFT units that prohibit bending at
the waist.
(8) Normal Breathing. Remove and re-don the respirator within a
one-minute period. Then, in a normal standing position, without
talking, the subject shall breathe normally for 1 minute.
After the test exercises, the test subject shall be questioned
by the test conductor regarding the acceptability of the respirator
upon completion of the protocol. If it has become unacceptable,
another model of respirator shall be tried.
(c) Portacount Test Instrument. (1) The Portacount will
automatically stop and calculate the overall fit factor for the
entire set of exercises. The overall fit factor is what counts. The
Pass or Fail message will indicate whether or not the test was
successful. If the test was a Pass, the fit test is over.
(2) A record of the test needs to be kept on file assuming the
fit test was successful. The record must contain the test subject's
name; overall fit factor; make, model and size of respirator used,
and date tested.
4. Controlled Negative Pressure (CNP) Protocol
The CNP protocol provides an alternative to aerosol fit test
methods. The CNP fit test method technology is based on exhausting
air from a temporarily sealed respirator facepiece to generate and
then maintain a constant negative pressure inside the facepiece. The
rate of air exhaust is controlled so that a constant negative
pressure is maintained in the respirator during the fit test. The
level of pressure is selected to replicate the mean inspiratory
pressure that causes leakage into the respirator under normal use
conditions. With pressure held constant, air flow out of the
respirator is equal to air flow into the respirator. Therefore,
measurement of the exhaust stream that is required to hold the
pressure in the temporarily sealed respirator constant yields a
direct measure of leakage air flow into the respirator.
The CNP fit test method measures leak rates through the
facepiece as a method for determining the facepiece fit for negative
pressure respirators. The CNP instrument manufacturer Dynatech
Nevada also provides attachments (sampling manifolds) that replace
the filter cartridges to permit fit testing in an employee's own
respirator. To perform the test, the test subject closes his or her
mouth and holds his or her breath, then an air pump removes air from
the respirator facepiece at a pre-selected constant pressure. The
facepiece fit is expressed as the leak rate through the facepiece,
expressed as milliliters per minute. The quality and validity of the
CNP fit tests are determined by the degree to which the in-mask
pressure tracks the challenge pressure during the system measurement
time of approximately five seconds. Instantaneous feedback in the
form of a real-time pressure trace of the in-mask pressure is
provided and used to determine test validity and quality. A minimum
fit factor pass level of 100 is necessary for a half-mask respirator
and a minimum fit factor of at least 500 is required for a full
facepiece respirator.
The entire screening and testing procedure shall be explained to
the test subject prior to the conduct of the screening test.
(a) CNP Fit Test Requirements--(1) The instrument shall have a
non-adjustable challenge pressure of 15.0 mm water pressure.
(2) The CNP system defaults for challenge pressure shall be
tested at -0.58 inches of water and the modeled inspiratory flow
rate shall be 53.8 liters per minute.
Note: CNP systems have built-in capability to conduct fit
testing that is specific to unique work rate, mask, and gender
situations that might apply in a specific workplace. Use of system
default values, which were selected to represent respirator wear
with medium cartridge resistance at a low-moderate work rate, will
allow inter-test comparison of the respirator fit.
(3) The individual who conducts the CNP fit testing shall be
thoroughly trained to perform the test.
(4) The respirator filter or cartridge needs to be replaced with
the CNP test manifold. The inhalation valve downstream from the
manifold either needs to be temporarily removed or propped open.
(5) The test subject shall be trained to hold his or her breath
for at least 20 seconds.
(6) The test subject shall don the test respirator without any
assistance from the individual who conducts the CNP fit test.
(7) The QNFT protocol shall be followed according to section
I.C.1 except that the CNP test exercises shall be used.
(b) CNP Test Exercises--(1) Normal breathing. In a normal
standing position, without talking, the subject shall breathe
normally for 1 minute. After the normal breathing exercise, the
subject needs to hold head straight ahead and hold his or her breath
for 10 seconds during the test measurement.
(2) Deep breathing. In a normal standing position, the subject
shall breathe slowly and deeply for 1 minute, taking caution not to
hyperventilate. After the deep breathing exercise, the subject needs
to hold head straight ahead and hold his or her breath for 10
seconds during test measurement.
(3) Turning head side to side. Standing in place, the subject
shall slowly turn his or her head from side to side between the
extreme positions on each side for 1 minute. The head shall be held
at each extreme momentarily so the subject can inhale at each side.
After the turning head side to side exercise, the subject needs to
hold head full left and hold his or her breath for 10 seconds during
test measurement. Next, the subject needs to hold head full right
and hold his or her breath for 10 seconds during test measurement.
(4) Moving head up and down. Standing in place, the subject
shall slowly move his or her head up and down for 1 minute. The
subject shall be instructed to inhale in the up position (i.e., when
looking toward the ceiling). After the moving head up and down
exercise, the subject needs to hold head full up and hold his or her
breath for 10 seconds during test measurement. Next, the subject
needs to hold head full down and hold his or her breath for 10
seconds during test measurement.
(5) Talking. The subject shall talk out loud slowly and loud
enough so as to be heard clearly by the test conductor. The subject
can read from a prepared text such as the Rainbow Passage, count
backward from 100, or recite a memorized poem or song for 1 minute.
After the talking exercise, the subject needs to hold his or her
head straight ahead and hold his or her breath for 10 seconds during
the test measurement.
(6) Grimace. The test subject shall grimace by smiling or
frowning for 15 seconds. After the grimace exercise, the subject
needs to hold his or her head straight ahead and hold his or her
breath for 10 seconds during the test measurement.
(7) Bending Over. The test subject shall bend at the waist as if
he or she were to touch his or her toes for 1 minute. Jogging in
place shall be substituted for this exercise in those test
environments such as shroud type QNFT units that prohibit bending at
the waist. After the bending over exercise, the subject needs to
hold his or her head straight ahead and hold his or her breath for
10 seconds during the test measurement.
(8) Normal Breathing. Remove and re-don the respirator within a
one-minute period. Then, in a normal standing position, without
talking, the subject shall breathe normally for 1 minute. After the
normal breathing exercise, the subject needs to hold his or her head
straight ahead and hold his or her breath for 10 seconds during the
test measurement.
After the test exercises, the test subject shall be questioned
by the test conductor regarding the acceptability of the respirator
upon completion of the protocol. If it has become unacceptable,
another model of a respirator shall be tried.
(c) CNP Test Instrument.--(1) The test instrument shall have an
effective audio warning device when the test subject fails to hold
his or her breath during the test. The test shall be terminated
whenever the test subject failed to hold his or her breath. The test
subject may be refitted and retested.
(2) A record of the test needs to be kept on file, assuming the
fit test was successful. The record must contain the test subject's
name; overall fit factor; make, model and size of respirator used,
and date tested.
Part II. Facepiece Fit Checks (Nonmandatory)
A. Positive pressure check. Close off the exhalation valve and
exhale gently into the facepiece. The face fit is considered
satisfactory if a slight positive pressure can be built up inside
the facepiece without any evidence of outward leakage of air at the
seal. For most respirators this method of leak testing requires the
wearer to first remove the exhalation valve cover before closing off
the exhalation valve and then carefully replacing it after the test.
B. Negative pressure check. Close off the inlet opening of the
canister or cartridge(s) by covering with the palm of the hand(s) or
by replacing the filter seal(s), inhale gently so that the facepiece
collapses slightly, and hold
[[Page 54299]]
the breath for ten seconds. If the facepiece remains in its slightly
collapsed condition and no inward leakage of air is detected, the
tightness of the respirator is considered satisfactory.
Appendix C to Sec. 1910.1035--Ventilation Chart for Isolation Rooms
or Areas (Mandatory)
Under paragraph(d)(5)(vii), the proposed standard requires that
when an AFB isolation room or area is vacated by an individual with
suspected or confirmed infectious TB, the room or area shall be
ventilated according to current CDC recommendations for a removal
efficiency of 99.9% before permitting employees to enter without
respiratory protection. The following appendix is an excerpt of the
CDC recommendations of the air changes per hour (ACH) and time in
minutes required for removal efficiencies of 90%, 99% and 99.9% of
airborne contaminants (Ex.4B). This table specifies the time
necessary to ventilate an isolation room or area, for a given air
change per hour, before allowing employees to enter without
respiratory protection.
Minutes required for a removal efficiency of:
------------------------------------------------------------------------
ACH 90% 99% 99.9%
------------------------------------------------------------------------
1................ 138 276 414
2................ 69 138 207
3................ 46 92 138
4................ 35 69 104
5................ 28 55 83
6................ 23 46 69
7................ 20 39 59
8................ 17 35 52
9................ 15 31 46
10............... 14 28 41
11............... 13 25 38
12............... 12 23 35
13............... 11 21 32
14............... 10 20 30
15............... 9 18 28
16............... 9 17 26
17............... 8 16 24
18............... 8 15 23
19............... 7 15 22
20............... 7 14 21
25............... 6 11 17
30............... 5 9 14
35............... 4 8 12
40............... 3 7 10
45............... 3 6 9
50............... 3 6 8
------------------------------------------------------------------------
This table has been adapted from the formula for the rate of purging
airborne contaminants. (Ex. 5-100) Values have been derived from the
formula t1 = [In (C2 + C2) + (Q +
V)] x 60, with t1 = 0 and C1 +
C2--(removal efficiency + 100), and where:
t1 = initial timepoint
C1 = initial concentration of contaminants
C2 = final concentration of contaminants
Q = air flow rate (cubic feet per hour)
V = room volume (cubic feet)
Q + V = ACH
The times given assume perfect mixing of air within the space (i.e.,
mixing factor = 1). However, perfect mixing usually does not occur,
and the mixing factor could be as high as 10 if air distribution is
very poor (Ex. 5-99). The required time is derived by multiplying
the appropriate time for the table by the mixing factor that has
been determined for the booth or room. The factor and required time
should be included in the operating instructions provided by the
manufacturer of the booth or enclosure, and these instructions
should be followed.
Appendix D to Sec. 1910.1035--Ultraviolet Radiation Safety and
Health Provisions (Nonmandatory)
This appendix sets forth non-mandatory guidelines on safety and
health provisions concerning the use of ultraviolet germicidal
irradiation (UVGI). Because the effectiveness of UVGI systems will
vary, and the interaction of factors such as humidity, UV intensity,
duration of exposure, lamp placement, and air mixing have not been
adequately evaluated, employers may choose to use UVGI systems as
supplements to the administrative, engineering, and work practice
controls required by this standard. OSHA does not consider UVGI as a
substitute or replacement for:
(1) Negative pressure;
(2) Exhaust of contaminated air directly to the outside away
from intake vents and employees;
(3) High efficiency particulate air (HEPA) filtration of
contaminated air before being recirculated to the general facility
or exhausted directly outside (permitted only when it cannot be
safely discharged).
UVGI Systems
The intent of UVGI systems is to kill or inactivate airborne
microorganisms, including M. tuberculosis. Two types of systems are
generally employed for this purpose: duct irradiation systems, and
upper room air irradiation systems. (Floor level UVGI systems are
used in some laboratory facilities, but are not specifically
discussed in this appendix.) UVGI systems utilize low-pressure
mercury vapor lamps that emit radiant energy predominantly at a
wavelength of 254 nanometers (nm).1 In duct irradiation
systems, one or more UV tubes are positioned within a duct to
irradiate air being exhausted from a room or facility. In upper room
air irradiation systems, UV lamps are suspended from a ceiling or
mounted on a wall. The lamps are positioned such that air in the
upper part of the room is irradiated. The intent is to minimize the
levels of UV radiation in the lower part of the room where the
occupants are located. These systems rely on air mixing to move the
air from the lower portion of the room to the upper portion of the
room where it can be irradiated.
Safety and Health Considerations
UV radiation at 254 nm is absorbed by the outer surfaces of the
eyes and skin. Overexposure to UVGI can result in photokeratitis
(inflammation of the cornea) and/or conjunctivitis (inflammation of
the conjunctiva).2 Keratoconjunctivitis is a reversible
condition but can be debilitating while it runs its course. Because
there is a latency period before health effects are observed,
workers may not recognize this as an occupational injury. Symptoms
may include a feeling of sand in the eyes, tearing, and sensitivity
to light. Overexposure of the skin to UVGI also can result in
erythema (reddening). This effect is also reversible, with recovery
occurring within 2 to 3 days.
In 1992, the International Agency for Research on Cancer (IARC)
classified UV-C radiation as ``probably carcinogenic to humans
(Group 2A)''.3 This classification was based on studies
suggesting that UV-C radiation can induce skin cancers in animals,
DNA and chromosome damage in human cells in vitro, and DNA damage in
mammalian skin cells in vivo. In the animal studies, exposure to UV-
B could not be excluded; however, the observed effects were greater
than expected for UV-B alone.\3\ Laboratory studies have shown that
UV radiation can activate human immunodeficiency virus (HIV) gene
promoters in human cells (genes in HIV that prompt replication of
the virus); however, the implications of these findings for humans
exposed to UVGI are
unknown.4,5,6,7,8,
9
Occupational Exposure Criteria for Ultraviolet Radiation
In 1972, the National Institute for Occupational Safety and
Health (NIOSH) published a recommended exposure limit (REL) for UV
radiation to prevent adverse effects on the eyes and skin.\2\ The
NIOSH REL for UV radiation is wavelength dependent because different
wavelengths of ultraviolet radiation have differing abilities to
cause skin and eye effects. The American Conference of Governmental
Industrial Hygienists (ACGIH) also has a Threshold Limit
Value for UV radiation that is identical to the REL in
this spectral region.10 It should be noted that
photosensitive individuals and those concomitantly exposed to
photosensitizing agents (including certain medications) may not be
protected by these occupational exposure limits.\10\
The term relative spectral effectiveness is used to compare UV
sources with a source producing UV radiation only at 270 nm, the
wavelength of maximum sensitivity for corneal injury. For example,
the relative spectral effectiveness (S) at 254 nm is 0.5;
therefore, twice as much energy is required at 254 nm to produce the
same biological effect at 270 nm. Thus, at 254 nm, the NIOSH REL is
0.006 joules per square centimeter (J/cm\2\), and at 270 nm it is
0.003 J/cm\2\.
For germicidal lamps, proper use of the REL (or TLV) requires
that the measured irradiance level (E) in microwatts per square
centimeter (W/cm\2\) be multiplied by the relative spectral
effectiveness at 254 nm (0.5) to obtain the effective irradiance
(Eeff). The maximum permissible exposure time (t) for
workers with unprotected eyes and skin can then be read directly
from Table 1 for selected values of Eeff, or can be
calculated (in seconds) by dividing 0.003 J/cm\2\ (the NIOSH REL at
270 nm) by Eeff in W/cm\2\. To protect workers who are
exposed to germicidal UV radiation for eight hours per day, the
measured irradiance (E), should be 0.2 W/cm\2\.
This is calculated by using Table 1 to obtain Eeff (0.1
W/cm\2\), and then dividing by S (0.5).
Example: If the measured irradiance was 0.4 W/cm\2\,
then the maximum permissible exposure time is 15,000 seconds, or
approximately 4 hours as shown below:
[[Page 54300]]
[GRAPHIC] [TIFF OMITTED] TP17OC97.008
Table 1--Maximum Permissible Exposure Times for Selected Values of Eeff.
------------------------------------------------------------------------
Effective
irradiance
Duration of exposure per day Eeff (W/cm\2\)
------------------------------------------------------------------------
8 hrs..................................................... 0.1
4 hrs..................................................... 0.2
2 hrs..................................................... 0.4
1 hr...................................................... 0.8
30 min.................................................... 1.7
15 min.................................................... 3.3
10 min.................................................... 5.0
5 min..................................................... 10.0
------------------------------------------------------------------------
This table was adapted from a table in Criteria for a Recommended
Standard . . . . Occupational Exposure to Ultraviolet Radiation.\2\
Maximum permissible exposure times refer to workers with unprotected
eyes and skin.
Measurement Equipment. A UV radiometer can be used to measure
the irradiance levels in the room and to document lamp output. Some
UV measurement systems rely on the use of a detector or probe which
is most sensitive at 254 nm, while others rely on the use of a
broad-band radiometer with an actinic probe. The latter instrument
has a response that accounts for the wavelength dependence of the
REL, allowing direct measurement of the effective irradiance
(Eeff).11 While both types of systems are
acceptable, persons performing the measurements should be aware of
the differences so that the measurements obtained are appropriately
compared with the recommended occupational exposure limits.
Equipment used to measure UV radiation should be maintained and
calibrated on a regular schedule, as recommended by the
manufacturer.
UVGI Safety and Health Program
Employers should consult with persons having expertise in
industrial hygiene, engineering, and/or health physics before
designing and installing UVGI systems. In addition, the following
guidelines should be used to protect workers from overexposure to UV
radiation. These guidelines should be incorporated into a UVGI
safety and health program. One person should be given responsibility
for managing the program.
(1) Exposure Monitoring
a. Upper Air Irradiation Systems. Before an upper air UVGI
system is activated in the workplace, exposure monitoring should be
conducted to determine the levels of UV radiation in the room. The
UV radiation levels will be affected by the position of the lamp,
fixture design (including presence and position of baffles and
louvers), tube type, room dimensions, and presence of UV absorbing
or reflecting materials. At a minimum, UV radiation measurements
should be made with the detector directly facing the lamp at head or
eye height (with maximum levels recorded), to assess the potential
UV exposure to the eyes, the most sensitive organ. Because workers
typically move around a room or area while performing their duties,
it is often not possible to predict how long a worker will be in a
given location, nor is it practical to attempt to control exposures
administratively by limiting the duration of exposure at a given
location. Therefore, the exposure monitoring should be conducted in
representative locations to adequately assess the range of potential
worker exposures. Worker exposures should be maintained below the
NIOSH REL \2\ and ACGIH TLV \10\ for ultraviolet radiation.
UV radiation measurements should be made: (1) at the time of
initial installation of the UVGI system; (2) whenever new tubes are
installed; and (3) whenever modifications are made to the UVGI
system or to the room that may affect worker exposures (i.e.,
adjustment of fixture height, location, or position of louvers;
addition of UV absorbing or reflecting materials; and changes in
room dimensions).
UV radiation measurements may also be obtained to document the
UV output of the lamp for tube replacement or other purposes.
Because these types of measurements are commonly done close to the
source of the UV output, the person obtaining the measurements may
be exposed to high levels of UV radiation. UV radiation levels up to
840 W/cm\2\ (420 /cm\2\ effective irradiance) have
been measured at a distance of four inches from the face of a 30W
tube that had been in use several months.12 Using the
NIOSH REL, this exposure level would result in a permissible
exposure time of only 7 seconds for workers with unprotected eyes
and skin. Because of the high irradiance levels, it would not be
practical in this situation to control UV exposures by limiting
exposure duration. Skin and eye protection would be needed to
protect the worker when making UV measurements close to the source.
b. Duct Irradiation Systems. Duct irradiation systems frequently
involve the placement of several UV tubes within a section of duct
work. Thus, workers who have contact with these lamps are
potentially exposed to high levels of UV radiation. This presents a
hazard for maintenance workers and others who are responsible for
documenting the UV output of these lamps. At one facility where a
duct irradiation system was used, UV radiation levels up to 950
W/cm\2\ were measured at a distance of approximately three
feet from a bank of four 39W UV tubes.\11\ In this situation, the
NIOSH REL would be exceeded in about 6 seconds; therefore, skin and
eye protection would be needed to prevent worker overexposures to UV
radiation. Most UV exposures resulting from duct irradiation systems
can be avoided by inactivating the lamps before maintenance work is
done, and providing an access port for viewing the lamps during
preventive maintenance inspections. These control measures are
discussed further in the Control Methods section of this appendix.
(2) Control Measures
The following control measures should be used to prevent or
reduce UV exposures.
a. Engineering Controls. 1. In upper air irradiation systems,
the UV tubes in the fixture should not be visible from any usual
location/position in the room. The fixtures should contain baffles
or louvers that are appropriately positioned to direct the UV
irradiation to the upper air space. The baffles and louvers should
be constructed so that they cannot be easily bent or deformed.
2. In upper air irradiation systems, all highly UV reflecting
material should be removed, replaced, or covered. Reflectance values
for various materials have been published.13 Etched
aluminum and chromium are examples of materials that have high
reflectance values (88 and 45% reflectance, respectively) for 254 nm
radiation. Unpainted white wall plaster is reported to have
reflectance values of 40-60%.\13\
3. UV-absorbing paints (such as those containing titanium
dioxide) can be used on ceilings and walls to minimize reflectance
of UV in the occupied space, as needed.
4. The on/off switch for the UVGI lamps should not be located on
the same switch as the general room lighting. In addition, these
switches should be positioned in such a location that only
authorized persons have access to them and they should be locked to
ensure that they are not accidentally turned on or off.
5. In duct irradiation systems, there should be an access panel
for conducting routine maintenance, monitoring, and cleaning. This
access panel should have an interlock or other device to ensure that
the tubes are deactivated whenever the panel is opened. To prevent
unnecessary UV exposures to maintenance personnel, this port should
have a window for viewing the tubes during routine inspections.
Ordinary glass (not quartz) and plastics (polycarbonate and
polymethylmethacrylate) are sufficient to filter out the UV
radiation.14
6. All UVGI systems should be inactivated prior to maintenance
activity in the affected areas, such as when maintenance workers
replace lamps or when entering the upper air space for room
maintenance, renovation, or repair work.
b. Personal Protective Equipment. UV exposures should be
maintained below existing recommended levels. Despite the use of the
engineering controls listed above, there may be situations when
worker exposures exceed the NIOSH REL, such as when UV measurements
are being made close to the lamp source in order to document lamp
output, or when maintenance procedures must be performed in areas
where UVGI systems are activated. In these and other situations
where the NIOSH REL is exceeded, personal protective equipment is
needed to prevent worker overexposure to UV radiation. This includes
the use of UV-absorbing eyewear with side-shields, head,
[[Page 54301]]
neck, and face covering opaque to UV radiation, gloves, and long-
sleeved garments. The weave of the fabric has been shown to be the
major factor affecting transmission of UV radiation,15
thus, tightly woven fabrics are recommended. UV-absorbing sunscreens
with solar-protection factors of 15 or higher may help protect
photosensitive persons.16
(3) Labeling
Warning labels should be placed on UV lamp fixtures in upper air
irradiation systems and on access panels in duct irradiation systems
to alert workers and other room occupants to this potential hazard.
These warning labels should be of sufficient size to be visible to
room occupants and should be in the appropriate language(s).
Examples of warning labels are shown below:
BILLING CODE 4510-26-P
BILLING CODE 4510-26-C
[GRAPHIC] [TIFF OMITTED] TP17OC97.009
(4) Training
All workers who have potential exposure to UV radiation from
UVGI systems should be receiving training on the hazards, relevant
symptoms, and precautions concerning exposure. This training should
include specific information on:
a. The rationale for use of UVGI and general principles of
operation, including its limitations;
b. Control measures used to prevent or reduce UV radiation
exposure;
c. Health effects associated with overexposure to UV radiation
(including the potential for additive exposure from other UV
sources, such as solar radiation and welding);
d. Recognition of the symptoms of eye and skin damage; and
e. Special precautions to be taken by workers to prevent
overexposure to UV radiation (including the use of personal
protective equipment).
(5) Medical Recommendations
The worker's medical history should be obtained to determine if
the worker suffers from any condition that may be exacerbated by
exposure to UV radiation. Workers should be advised that any eye or
skin irritation that develops after acute exposure to UV radiation,
or any skin lesion that appears on skin repeatedly exposed to UV
radiation should be examined by a physician.
(6) Recordkeeping
The employer should maintain accurate and complete records
pertaining to the following:
a. Exposure monitoring;
b. Instrument calibration;
c. Documentation of health effects;
d. Training;
e. Maintenance of UVGI systems, including cleaning and
replacement of tubes.
References
1. IES [1966]. Illuminating Engineering Society (IES) lighting
handbook, 4th ed., IES, New York, 25-27.
2. NIOSH [1972]. Criteria for a recommended standard . . .
occupational exposure to ultraviolet radiation. U.S. Department of
Health, Education, and Welfare, Public Health Service, Health
Services and Mental Health Administration, National Institute for
Occupational Safety and Health, Washington, DC, HSM-11009.
3. IARC [1992]. IARC monographs on the evaluation of
carcinogenic risks to humans: solar and ultraviolet radiation. Vol.
55. Lyon, France: World Health Organization, International Agency
for Research on Cancer.
4. Valerie K, Delers A, Bruck C, Thiriart C, Rosenberg H,
Debouck C, Rosenberg M [1988]. Activation of human immunodeficiency
virus type 1 by DNA damage in human cells. Nature 333:78-81.
5. Zmudzka BZ, Beer JZ [1990]. Activation of human
immunodeficiency virus by ultraviolet radiation (yearly review).
Photochem and Photobiol, 52:1153-1162.
6. Wallace BM, Lasker JS [1992]. Awakenings . . . UV light and
HIV gene activation. Science, 257:1211-1212.
7. Valerie K, Rosenberg M [1990]. Chromatin structure implicated
in activation of HIV-1 gene expression by ultraviolet light. The New
Biologist, 2:712-718.
8. Stein B, Rahmsdorf HJ, Steffen A, Litfin M, Herrlich P
[1989]. UV-induced DNA damage is an intermediate step in UV-induced
expression of human immunodeficiency virus type 1, collagenase, C-
fos, and metallathionein. Mol Cell Biol, 9:5169.
9. Clerici M, Shearer GM [1992]. UV light exposure and HIV
replication. Science, 11/13/92:1070-1071.
10. ACGIH [1994]. 1994-1995 Threshold limit values for chemical
substances and physical agents and biological exposure indices.
American Conference of Governmental Industrial Hygienists,
Cincinnati, OH: ACGIH.
11. Murray WE [1990]. Ultraviolet radiation exposures in a
mycobacteriology laboratory. Health Physics, 58(4):507-510.
12. NIOSH [1992]. Hazard evaluation and technical assistance
report: Onondaga County Medical Examiner's Office, Syracuse, New
York. Cincinnati, OH: U.S. Department of Health and Human Services,
Public Health Service, Centers for Disease Control and Prevention,
National Institute for Occupational Safety and Health, (NIOSH Report
No. HETA 92-171-2255).
13. Summer W [1962]. Ultra-violet and infra-red engineering. New
York: Interscience Publishers, p 300.
14. Sliney DH, Wolbarsht ML [1982]. Safety with lasers and other
optical sources. 3rd Printing. New York: Plenum Press.
15. Gies HP, Roy CR, Elliott G [1994]. Ultraviolet radiation
protection factors for clothing. Health Physics 67(2):131-139.
16. CDC [1994]. Guidelines for preventing the transmission of
tuberculosis in health-care facilities, second edition. Atlanta, GA:
Centers for Disease Control and Prevention.
Appendix E to Sec. 1910.1035--Performance Monitoring Procedures for
HEPA Filters (Nonmandatory)
This appendix offers nonmandatory guidance on design
considerations and performance monitoring of HEPA filters used in
air systems that carry air that may reasonably be anticipated to
contain aerosolized M. tuberculosis (e.g., recirculation into
building circulating air system, exhausting outdoors near air
intakes, etc.).
Both OSHA and CDC recommend against the recirculation of air
that may reasonably be anticipated to contain aerosolized M.
tuberculosis into the general circulating air system of the building
or other opportunities where such air may become entrained into the
circulating air system (e.g., outdoor exhausting near intakes,
transfer to heat wheels, etc.). When recirculation is unavoidable,
the air should be cleaned with HEPA filtration. In order to assure
effective functioning of these systems, they should be properly
designed, installed, and maintained.
Design of HEPA Filtration Systems
The following elements should be considered for incorporation
into the design of HEPA filtration systems:
1. Provide upstream prefiltering to reduce dust that may plug
the HEPA filter.
2. Provide worker-entry into housings for visual examinations
and probe scanning for leaks of filter media and frame-to-filter
interfaces. In addition, adequate access should be provided to allow
for replacement of the HEPA filters and pre-filters without
contaminating the work area by unintentional jarring or dropping of
the filters.
3. Provide devices for measuring HEPA filter loading (e.g.,
pressure differential across a filter).
4. Provide appropriate mounting frames and seals to minimize
frame-to-filter leakage.
5. Specify filter media to match operating criteria (e.g., face
velocity, volumetric flow rate, pressure drop, etc.).
6. Design upstream and downstream duct to facilitate performance
monitoring (e.g., good air mixing for uniform dispersal of challenge
aerosols, sectioning to allow isolation of leaks, etc.).
7. HEPA filters must operate in dry airstreams. Tests have shown
that exposure
[[Page 54302]]
to high humidity for a period of five hours will result in a
threefold increase in particle penetration.
Maintenance of HEPA Filtration Systems
HEPA filtration systems are generally passive systems without
moving parts, so the majority of filter maintenance activities are
associated with performance monitoring. In terms of performance
monitoring, HEPA filters are to be monitored for filter loading and
for possible leakage every 6 months, whenever filters are changed,
and more often if necessary to maintain effectiveness. Leaks in HEPA
filters can occur in the following ways: (1) in the filter media,
(2) in the bond between media and frame, (3) in the frame gasket,
(4) in the support frame, and (5) in between the frame and the wall.
Testing of HEPA filters after installation is used to detect
leaks associated with shipping damage and with installation problems
such as handling damage, variations in gasket thickness and poorly
formed gasket corners.
Periodic testing detects deterioration of components, relaxation
of gaskets, clamping devices, weld cracks or other leaks that may
develop during use. This deterioration will take place even if the
system is not on-line and in use.
Monitoring for Filter Loading
HEPA filtration systems become loaded with particulate matter
through use. Although this loading improves particulate arrestance,
it eventually increases the pressure drop across the filter
assembly. Consequently, the flow capacity begins to diminish and
bypass leakage at the frame-to-filter interface increases.
Therefore, these filters need to be monitored and changed.
It is imperative that the differential pressures across the HEPA
filter remain below the maximum operating resistance level set by
the manufacturer and stamped on the filter label. Filter penetration
by contaminants can occur when HEPA filters exceed the
manufacturer's maximum resistance rating, making the system
ineffective.
The operating resistance level is determined by measuring the
pressure differential across the filter through use of a pressure
sensing device. Measurements of differential pressure across the
HEPA filters should be made when the prefilters have been removed.
These measurements should be used to predict future HEPA filter
replacement or for determining the need for immediate HEPA filter
replacement. Additional control measures can be used to detect a
differential pressure that exceeds the maximum operating resistance
which signals the alarm's set point (i.e., audible/visual alarms or
computerized error messages).
All pressure measurements should be logged and retained in
accordance with paragraph (i)(4)(ii) of this standard.
Monitoring for In-service Filter Leakage
In CDC's ``Guidelines for Preventing the Transmission of
Mycobacterium tuberculosis in Health-Care Facilities'' [Ex. 4B], the
di-octal phthalate (DOP) penetration test as described in Chapter 25
of the 1992 Systems Handbook from the American Society of Heating,
Refrigerating and Air-Conditioning Engineers (ASHRAE) is offered as
a method of performance monitoring HEPA filters. The basis of this
well-recognized test is to challenge a HEPA filter assembly with a
uniformly distributed cloud of 0.3 m (mass median diameter)
DOP aerosol and measure the DOP smoke upstream and downstream with a
light-scattering photometer. Penetration ``P'' through the filter
assembly is the performance criterion typically specified and is
defined as:
[GRAPHIC] [TIFF OMITTED] TP17OC97.010
Penetration is related to filter efficiency ``E'' by the
equation:
E=100(1-P)%
Therefore, an efficiency of 99.97% is equivalent to P=0.0003.
Other Filter Testing Methods
There are many recognized HEPA filter testing standards. Most of
these standards utilize DOP aerosol to challenge the HEPA filters
and provide penetration performance data for 0.3 m size
particles. Since TB droplet nuclei range in size from 1 to 5
m, the DOP aerosol challenge is indicative of droplet
nuclei penetration. Some manufacturers may provide bench test data
for filtration efficiency versus particle size which may be useful
information when selecting filters but may be difficult to duplicate
in the field for in-service testing. These test standards include:
1. Standard UL 586, High-Efficiency, Particulate, Air Filter
Units as published by Underwriters Laboratories, 1990 (Ex. 7-227).
This test is designed for bench testing at the factory and does not
include the frame-to-filter bypass leakage measured by in-service
testing. This test method uses a light beam-photocell combination
(photometer) to measure the density of the DOP smoke in the air.
2. Standard ASTM F1471-92, Air Cleaning Performance of a High-
Efficiency Particulate Air-Filter System, as published by the
American Society for Testing and Materials, 1993 (Ex. 7-222). This
test can be used in the field for in-service testing of HEPA
filters. This test method utilizes a laser aerosol spectrometer
which can count particles by particle size.
3. Standard NSF-49, Appendix B, HEPA Filter Leak Test for
Biosafety Cabinets, as published by the National Sanitation
Foundation (Ex. 7-226). This test is designed for in-service HEPA
filter testing and utilizes a portable photometer probe which can be
passed over the filter frame perimeter to check for bypass leaks.
Unfortunately, there are hazards associated with exposure to
DOP. The Material Safety Data Sheet for DOP reports irritation,
nausea and numbness as symptoms associated with DOP inhalation.
Nausea, diarrhea, reproductive effects, liver enlargement, and
cancer are effects associated with ingestion of DOP. Therefore,
performance testing that does not utilize DOP should also be
considered.
Alternative methods are in use and being developed that
capitalize on recently developed optical particle counters (e.g.,
lasers) that can count particles at specified sizes. For example,
the National Environmental Balancing Bureau (NEBB) publishes
Procedural Standards for Certified Testing of Clean rooms' Section
8.3 presents an Ambient Particle Aerosol Challenge Method that
utilizes new-generation optical particle counters to measure
upstream and downstream concentrations of particles of a specified
size (Ex. 7-228). Only ambient air is measured and no aerosol is
generated. This method may have merit for TB applications because
ambient air has a statistically significant quantity of particles
less than 3.0 m, but at the same time, this high number of
particles may overload the instrument.
Because a dark DOP smoke is not required to attenuate light as
is the case with a photometer, recently developed optical particle
counters offer the opportunity for an alternative non-toxic
challenge aerosol like that described in the proposed Standard 52.2
Method of Testing General Ventilation Air-Cleaning Devices for
Removal Efficiency by Particle Size from the American Society of
Heating, Refrigerating and Air-Conditioning Engineers. This non-
toxic challenge aerosol is based upon potassium chloride (KC)
particles which are generated in the 0.3 to 10 m size range
(Ex. 7-224).
Filter Testing Performance Criteria
The following should be considered when setting performance
testing criteria: (1) Failure of a HEPA filter in a recirculating
air system can have serious consequences; (2) HEPA filters are more
efficient in removing droplet nuclei than DOP due to the larger
particle size of droplet nuclei; (3) In-service filter penetration
testing should match factory testing that is P