04-5855. National Institute for Occupational Safety and Health; Meeting

The National Institute for Occupational Safety and Health (NIOSH) of the Centers for Disease Control and Prevention (CDC) announces the following meeting and request for information:

Name: Discussion of the Health Risks Associated with Occupational Exposure to Titanium Dioxide.

Time and Date: 9 a.m.-4 p.m., April 29, 2004.

Place: Robert A. Taft Laboratories, Taft Auditorium, NIOSH, CDC, 4676 Columbia Parkway, Cincinnati, Ohio 45226.

Status: The forum will include scientists and representatives from various government agencies, industry, labor, and other stakeholders, and is open to the public, limited only by the space available. The meeting room accommodates 80 people. Due to limited space, notification of intent to attend the meeting must be made to Diane Miller no later than Friday, April 16, 2004. Ms. Miller can be reached by telephone at 513/533-8450 or by email at [e-mail]. Requests to attend the meeting will be accommodated on a first-come basis.

Purpose: To discuss the health data relevant to titanium dioxide exposure and the scientific and technical issues associated with the development of recommended exposure limits. Special emphasis will be placed on discussion of the following:

(1) What animal and human data best describe the health concerns from exposure to titanium dioxide?

(2) What strategies are being used to control occupational exposure to titanium dioxide (e.g., engineering controls, work practices, personal protective equipment)?

(3) At what workplaces and occupations can exposure to titanium dioxide occur?

(4) What challenges exist in measuring workplace exposures to titanium dioxide?

(5) What are areas of future collaborative efforts (e.g., research, communication, development of exposure measurement and control strategies)?

The public is invited to attend and will have the opportunity to provide comments.

Summary: NIOSH currently recommends that titanium dioxide be considered a potential occupational carcinogen. A review of the recent literature indicates that the NIOSH recommendation may not adequately reflect current scientific information about the potential biological activity of titanium dioxide and other similar substances that have poor solubility and can occur in the workplace. Recent evidence suggests that these substances, which generally have been regarded as causing minimal toxicity in humans, may pose different levels of risk depending on their particle size. Ultrafine particles appear to be more toxic than an equivalent mass dose of larger respirable particles, an effect that appears to be related to the total particle surface area. Moreover, when the exposure-response data are evaluated from studies in rats exposed to titanium dioxide and other similar substances, there appears to be a consistent response that is related to particle surface area. NIOSH presently is reviewing the available toxicity data on titanium dioxide, as well as other relevant health data associated with particle surface area, with the intent of developing new workplace recommendations for titanium dioxide, including recommended exposure limits (RELs).

NIOSH seeks to obtain materials, including published and unpublished reports and research findings, to evaluate the possible health risks of occupational exposure to titanium dioxide (including particle size-specific information). Examples of requested information include, but are not to be limited to, the following:

(1) Identification of industries or occupations in which exposures to titanium dioxide may occur.

(2) Trends in the production and use of titanium dioxide.

(3) Description of work tasks and scenarios with a potential for exposure to titanium dioxide.

(4) Current and historical exposure measurement data in various types of industries and jobs.

(5) Case reports or other health information demonstrating health effects in workers exposed to titanium dioxide.

(6) Reports of experimental in vivo and in vitro studies that provide evidence of a dose-relationship between the particle size of a substance and its biological activity.

(7) Reports of experimental inhalation studies with rodents demonstrating a relationship between the particle size or surface area of a substance and lung inflammation, fibrosis, and biochemical mediators.

(8) Description of work practices and engineering controls used to reduce or prevent workplace exposure to titanium dioxide.

(9) Educational materials for worker safety and training on the safe handling of titanium dioxide.

(10) Data pertaining to the feasibility of establishing particle size-specific RELs for titanium dioxide.

NIOSH will use this information to determine the need for developing new recommendations for reducing occupational exposure to titanium dioxide.

ADDRESSES:

Comments should be submitted to the NIOSH Docket Office, ATTN: Diane Miller, Robert A. Taft Laboratories, 4676 Columbia Parkway, Cincinnati, Ohio 45226, telephone [phone], fax [phone]. Comments may also be submitted by email to: [e-mail]. Email attachments should be formatted as Microsoft Word. Comments should be submitted to NIOSH no later than April 16, 2004, and should reference docket number NIOSH-033 in the subject heading.

All information received in response to this notice will be available for public examination and copying at the NIOSH Docket Office, 4676 Columbia Parkway, Cincinnati, Ohio 45226.

Contact Persons for Technical Information: Eileen Kuempel, M/S C-15, Robert A. Taft Laboratories, 4676 Columbia Parkway, Cincinnati, Ohio 45226, 513/533-8363, or Ralph Zumwalde, M/S C-32, Robert A. Taft Laboratories, 4676 Columbia Parkway, Cincinnati, Ohio 45226, 513/533-8320.

The Director, Management Analysis and Services Office, has been delegated the authority to sign Federal Register Notices pertaining to announcements of meetings and other committee management activities, for both CDC and the Agency for Toxic Substances and Disease Registry.

Dated: March 9, 2004.

Alvin Hall,

Director, Management Analysis and Services Office, Centers for Disease Control and Prevention.