[Federal Register Volume 61, Number 135 (Friday, July 12, 1996)]
[Rules and Regulations]
[Pages 36790-36807]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-16861]
[[Page 36789]]
_______________________________________________________________________
Part II
Department of Labor
_______________________________________________________________________
Mine Safety and Health Administration
_______________________________________________________________________
30 CFR Parts 56 and 57
Safety Standards for Explosives at Metal and Nonmetal Mines; Final Rule
Federal Register / Vol. 61, No. 135 / July 12, 1996 / Rules and
Regulations
[[Page 36790]]
DEPARTMENT OF LABOR
Mine Safety and Health Administration
30 CFR Parts 56 and 57
RIN 1219-AA84
Safety Standards for Explosives at Metal and Nonmetal Mines
AGENCY: Mine Safety and Health Administration, Labor.
ACTION: Final rule.
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SUMMARY: This final rule revises certain provisions of the Mine Safety
and Health Administration's (MSHA) safety standards for explosives at
metal and nonmetal mines. The final rule revises existing standards for
separation of detonators from other explosives or blasting agents
during storage in powder chests and during transportation.
Additionally, it revises existing provisions related to loading and
blasting of explosive materials. The final rule also expands the
application of existing provisions concerning the protection of
explosive materials from impact and exposure to high temperatures, and
it revises and clarifies the existing provisions addressing static
electricity dissipation during loading. The rule revises the existing
preamble discussion for vehicles containing explosive material, and
incorporates existing blast site security provisions into the loading
and blasting standards. For the convenience of the mining community,
MSHA has published the full text of the explosives standards for metal
and nonmetal mines in this Federal Register document.
EFFECTIVE DATES: This final rule is effective September 10, 1996. The
incorporation by reference listed in the regulations is effective
September 10, 1996.
FOR FURTHER INFORMATION CONTACT: Patricia W. Silvey, Director, Office
of Standards, Regulations, and Variances, MSHA, 703-235-1910.
SUPPLEMENTARY INFORMATION:
I. Paperwork Reduction Act
Under final Secs. 56/57.6306(a), operators must either attend;
barricade and post the blast site with warning signs, such as
``Danger,'' ``Explosives,'' or ``Keep Out;'' or flag the blast site
against unauthorized entry. These final requirements for use of warning
signs, such as ``Danger,'' ``Explosives,'' or ``Keep Out,'' are not
considered information collection under the Paperwork Reduction Act of
1995 (PRA 95) and are not subject to approval by the Office of
Management and Budget (OMB).
Final Secs. 56/57.6306(d) requires that operators conduct loading
and blasting in a manner to facilitate a continuous process so that the
blast is fired as soon as possible. The final standard does not retain
the concept of ``undue delay'', but retains the existing requirement to
notify MSHA of blasting delays beyond 72 hours. MSHA estimates that
these provisions affect fewer than 10 respondents annually, all large
mines. Although notification is considered an information collection
burden under PRA 95, this provision is not subject to OMB approval
because it affects fewer than 10 respondents annually.
II. Rulemaking Background
MSHA published comprehensive revisions to its explosives safety
standards for metal and nonmetal mines in January 1991 (56 FR 2070).
Prior to the effective date of the rule, MSHA stayed several provisions
due to compliance issues raised by the mining community and explosives
manufacturers. The provisions involved were subsequently reproposed on
October 16, 1992 (57 FR 47524) for revision and clarification. On
December 30, 1993, MSHA published the existing final rule which became
effective on January 31, 1994 (58 FR 69596).
In February 1994, the American Mining Congress (AMC) and the
Institute of Makers of Explosives (IME) each filed a petition for
review of the final rule with the United States Court of Appeals for
the District of Columbia Circuit, in American Mining Congress v. MSHA,
Docket No. 91-1124 and 91-1568, consolidated cases, and in IME v. MSHA,
Docket No. 94-1144. AMC requested that MSHA reconsider evidence in the
rulemaking record regarding the continuous loading requirements of
Secs. 56/57.6306(c), Loading and blasting. In addition, AMC requested
that the Agency clarify the preamble discussion to Secs. 56/
57.6202(a)(1), concerning vehicles containing explosive materials.
IME suggested revision of Secs. 56/57.6000, the definition of
``laminated partition,'' and corresponding changes in Secs. 56/
57.6133(b), Powder chests, and Secs. 56/57.6201(a)(2) and (b)(2),
Separation of transported explosive material. Also, IME requested that
MSHA reconsider information in the rulemaking record regarding the
requirements of Secs. 56/57.6602, Static electricity dissipation during
loading.
In response to the issues raised by the mining industry and
explosive manufacturers, MSHA issued Program Policy Letter No. P94-IV-3
on September 30, 1994. This Program Policy Letter provided information
to the mining community regarding the proper usage of the IME-22
Container as a ``laminated partition'' under Secs. 56/57.6000,
Secs. 56/57.6133, and Secs. 56/57.6201. The Agency also interpreted the
``continuous loading'' requirements of Secs. 56/57.6306; clarified the
meaning of the term ``good condition'' as it applies to vehicles used
in Secs. 56/57.6202; clarified the application of Secs. 56/57.6501
regarding double trunklines or loop systems when using low energy
detonating cord with inhole delays; and interpreted Secs. 56/57.6602(e)
on static electricity dissipation during loading as it applies to the
use of plastic hole liners. This final regulation addresses these
regulatory issues except for Secs. 56/57.6501 regarding double
trunklines or loop systems. Therefore, Program Policy Letter No. P94-
IV-3 will expire on the effective date of this final regulation.
On January 5, 1995, MSHA published a proposed rule in the Federal
Register (60 FR 1866) which would have revised the provisions discussed
above. Public hearings were held in Cleveland, Ohio, and Elko, Nevada
in July 1995. The rulemaking record closed on August 18, 1995. MSHA
received and reviewed written and oral statements on the proposed rule
from all segments of the mining community. These final standards for
explosives at metal and nonmetal mines are based on consideration of
the entire rulemaking record, including all written comments and
exhibits received related to the January 1991 and the December 1993
final regulations, as well as the January 5, 1995, proposal and the
public hearing record.
To serve the interests of the mining community, MSHA has
republished the full text of subpart E of 30 CFR parts 56 and 57 as
they will read effective September 10, 1996. This final rule, however,
addresses revisions only to the following sections. Sections
republished here and not on the list below are unchanged.
Parts 56 and 57
Secs. 56/57.6000 Definitions.
Secs. 56/57.6133 owder chests.
Secs. 56/57.6201 Separation of transported explosive material.
Secs. 56/57.6202 Vehicles.
Secs. 56/57.6302 Separation of explosive material.
Secs. 56/57.6306 Loading, blasting, and security.
Secs. 56/57.6313 Blast site security.
Secs. 56/57.6602 Static electricity dissipation during loading.
[[Page 36791]]
Secs. 56/57.6905 Protection of explosive material.
III. Discussion and Summary of the Final Rule
A. General Discussion
Historically, hazards associated with the storage, transportation,
and use of explosive materials have caused or contributed to serious
injuries and fatalities in metal and nonmetal mines. Precautions to
safeguard against these hazards are an essential part of any effective
mine safety program. The standards in 30 CFR parts 56 and 57, subpart
E, focus on hazards associated with using or working near explosive
materials at metal and nonmetal mines. The standards in this final rule
clarify and address certain precautions necessary to prevent the
hazards common to storing, transporting, and handling explosive
materials. These standards also address the issues raised in the rule
challenges noted above.
B. Organizational Changes
Paragraph (b) of existing Secs. 56/57.6302 is moved to Secs. 56/
57.6905 of this subpart. Paragraph (a) of existing Secs. 56/57.6302
requires that explosives and blasting agents be kept separate from
detonators until loading begins. This provision remains unchanged. The
section heading of Secs. 56/57.6302 is revised in the final rule to
read ``Separation of explosive material.''
Paragraph (b) of existing Secs. 56/57.6302 requires that explosive
material be protected from impact and temperatures in excess of 150
degrees Fahrenheit when taken to the blast site.
In 1993, MSHA promulgated Secs. 56/57.6302 under the ``Use''
portion of the explosives regulation, thereby inadvertently creating
confusion as to whether explosives also must be protected from impact
during transportation and storage. MSHA's intent was to require
protection of explosive material from impact and high temperatures
generally, not just during use. This final rule moves existing
paragraph (b) of Secs. 56/57.6302 to ``General Requirements'' and
``General Requirements-Surface and Underground.'' The provision is
codified as Secs. 56/57.6905, with the section heading ``Protection of
explosive material.''
C. Deletions
Existing Secs. 56/57.6313, which require that areas where loading
is suspended or loaded holes are awaiting firing be attended,
barricaded and posted, or flagged against unauthorized entry are
deleted, and these requirements are incorporated into final Secs. 56/
57.6306(a) for loading and blasting.
D. Incorporations by Reference
Existing Secs. 56/57.6000, Secs. 56/57.6133, and Secs. 56/57.6201
incorporate by reference the definition of ``laminated partition'' and
recommendations found in the IME Safety Library Publication No. 22,
``Recommendations for the Safe Transportation of Detonators in a
Vehicle with other Explosive Materials,'' (May 1993), and ``The Generic
Loading Guide for the IME-22 Container,'' (October 1993). Whenever a
laminated partition is used under the final rule, IME's recommendations
contained in these two publications must be followed. As discussed
below, MSHA will make these IME publications available to the mining
community.
E. Section-by-Section Analysis
The following section-by-section analysis explains the final rule
and its effect on existing standards. The standards in part 56 apply to
all surface metal and nonmetal mines; those in part 57 apply to
underground and surface areas of underground metal and nonmetal mines.
Secs. 56/57.6000 Definitions.
Secs. 56/57.6133 Powder chests.
Secs. 56/57.6201 Separation of transported explosive material.
Sections 56/57.6133 and 56/57.6201 address the hazards of unplanned
detonation of explosives when stored and transported. The separation
requirements are intended to impede propagation should detonators be
initiated.
The existing definition of ``laminated partition'' in 30 CFR
Secs. 56/57.6000 includes the combinations of materials which must be
used in a partition if operators choose to store or transport certain
detonators with explosives or blasting agents. These dimensions are
based on IME Safety Library Publication No. 22, ``Recommendations for
the Safe Transportation of Detonators in a Vehicle with other Explosive
Materials,'' (May 1993), and the ``Generic Loading Guide for the IME-22
Container,'' (October 1993). The term ``laminated partition'' appears
in existing Secs. 56/57.6133, Powder chests, and in Secs. 56/57.6201,
Separation of transported explosive material.
Existing standards Secs. 56/57.6133 require that detonators stored
at surface operations and at surface areas of underground operations
must be kept in chests separate from other explosives or blasting
agents, unless the detonators and explosives or blasting agents are
separated by 4 inches of hardwood or equivalent, or a laminated
partition. Similarly, existing Secs. 56/57.6201(a)(2) require
detonators and other explosives or blasting agents to be transported on
separate vehicles or conveyances, except detonators in quantities of
more than 1,000 may be transported on the same vehicle or conveyance if
maintained in the manufacturer's original packaging, and if separated
from explosives or blasting agents by 4 inches of hardwood or
equivalent, or a laminated partition. The 4 inches of hardwood or
equivalent must be fastened to the vehicle or conveyance. Paragraph
(b)(2) of Secs. 56/57.6201 allows detonators in quantities of 1,000 or
fewer to be transported with explosives or blasting agents when kept in
closed containers and separated by 4 inches of hardwood or equivalent,
or a laminated partition. The 4 inches of hardwood or equivalent must
be fastened to the vehicle or conveyance.
The Institute of Makers of Explosives (IME) raised objections to
these existing regulations since the IME safety guidelines warn against
hazards associated with use of the IME-22 container when transporting
detonators with other explosives and blasting agents on the same
vehicle.
Proposed Secs. 56/57.6000 included language similar to that of the
existing regulation. Proposed Secs. 56/57.6133(b) would have allowed
operators the flexibility to continue storing detonators with other
explosives and blasting agents in a powder chest (day box) when
separated by 4 inches of hardwood or equivalent. Likewise, proposed
Secs. 56/57.6201 (a)(2) and (b)(2) would have allowed operators to
continue transporting detonators with explosives and blasting agents on
the same vehicle or conveyance if they are separated by 4 inches of
hardwood or equivalent. In response to IME's comments, both proposed
standards also would have allowed use of a laminated partition to
separate detonators from explosive materials, provided operators
followed guidelines included in the IME Safety Library Publication No.
22, ``Recommendations for the Safe Transportation of Detonators in a
Vehicle with other Explosive Materials,'' (May 1993), and the ``Generic
Loading Guide for the IME-22 Container'' (October 1993) when using a
laminated partition.
Final regulations for Secs. 56/57.6000 are the same as the proposed
rule. The final regulations for both Secs. 56/57.6133(b) and Secs. 56/
57.6201 (a)(2) and (b)(2) parallel the proposed rules in that they
permit the longstanding practice of using 4 inches of hardwood or
[[Page 36792]]
equivalent, or a laminated partition (which includes the IME-22
Container or box) to separate detonators from other explosives or
blasting agents, provided that the provisions of the IME Safety Library
Publication No. 22, ``Recommendations for the Safe Transportation of
Detonators in a Vehicle with other Explosive Materials,'' (May 1993),
and the ``Generic Loading Guide for the IME-22 Container'' (October
1993) are followed. Copies of these IME publications are available to
the mining industry at MSHA headquarters in Arlington, VA, and at all
Metal and Nonmetal Mine Safety and Health district offices.
MSHA did not receive any comments relative to the Agency's
definition of the term ``laminated partition'' as described in the
proposed rule.
One commenter objected to MSHA incorporating by reference IME
publications stating that such incorporation would interfere with the
opportunity to comment on the content of these publications. MSHA has
historically relied upon manufacturers' design specifications and
recommendations for the proper use of specific mining equipment and
machinery where unintended use of such equipment and machinery poses a
serious safety hazard to miners. Therefore, if operators use a
laminated partition for compliance with standards Secs. 56/57.6133 and
Secs. 56/57.6201, they must follow the guidelines prescribed in IME's
accompanying documentation, including updated revisions where
applicable. MSHA expects that the IME will periodically update this
documentation, and MSHA intends to give mine operators adequate notice
should compliance changes become necessary.
Some commenters sought clarification of the phrase ``4 inches of
hardwood, or equivalent,'' as used in proposed Secs. 56/57.6133 and
Secs. 56/57.6201, while other commenters requested that MSHA define the
term ``equivalent'' in the final regulation to specify the types of or
combinations of materials that would be accepted. ``Equivalent'' under
the final rule refers to any barrier, other than a laminated partition,
that provides at least the same degree of protection for explosives or
blasting agents as 4 inches of hardwood should detonators be initiated
by outside forces. Presently, MSHA has no equivalency data to convert
the degree of protection provided by hardwood to another material.
However, the final standard preserves the flexibility to recognize such
future developments.
One commenter requested that MSHA clarify whether ``4 inches of
hardwood'' refers to a partition separating two containers or to the
construction of the detonator box itself. The 4 inches of hardwood or
its equivalent refers to the partition used to separate explosives and
blasting agents from detonators. The purpose of separation is to impede
propagation should detonators be initiated by outside forces. The 4
inches of hardwood or equivalent separator must be fastened inside the
cargo area of the vehicle or conveyance containing explosive materials.
At commenters' suggestions, mine operators are reminded that MSHA
standards are applicable only to mining property, including
transporting of explosive materials. Any transportation of explosive
material over public highways is subject to the requirements of the
United States Department of Transportation in Title 49 of the Code of
Federal Regulations.
Sections 56/57.6202 Vehicles
Sections 56/57.6202 address the hazard of an unplanned detonation
of explosive material during transportation. Detonation can result from
vehicle fires, vehicle accidents or construction of an explosive
container with inappropriate material.
The existing regulations at Secs. 56/57.6202(a)(1) require that
vehicles used to transport explosives be maintained in ``good
condition.'' MSHA indicated in the preamble discussion to this
regulation that for compliance purposes, vehicles must be road-worthy
and capable of passing Federal, state, and local licensing requirements
for over-the-road use.
MSHA received a number of objections to this interpretation of
``good condition.'' In response to these commenters, MSHA clarifies in
this final regulation preamble that for vehicles to be in ``good
condition'' that they comply with the applicable MSHA standards
contained in subpart M-Machinery and Equipment, which address
requirements for all self-propelled mobile equipment used on mine
property. Commenters agreed with this interpretation and MSHA adopts
this approach in the final rule.
``USE''
Sections 56/57.6302 Separation of Explosive Material and Sections 56/
57.6905 Protection of Explosive Material
Sections 56/57.6302 address the hazard of unplanned detonation of
explosive material and protection for explosive material during use,
transportation, and prior to loading.
Existing paragraph (a) of Secs. 56/57.6302 requires that explosives
and blasting agents be kept separate from detonators until loading
begins. Existing paragraph (b) requires that explosive material be
protected from impact and temperatures in excess of 150 degrees
Fahrenheit when taken to the blast site.
When MSHA promulgated existing Secs. 56/57.6302, the standards
appeared in the ``USE'' portion of the explosives regulations, although
the same hazards also exist during the transportation and storage
processes. Therefore, the final rule revises and expands application of
existing paragraph (b) of Secs. 56/57.6302 to ``GENERAL REQUIREMENTS''
for both surface and underground, and moves this existing paragraph to
newly numbered standards Secs. 56/57.6905. Like the proposed
regulation, final paragraph (a) requires that operators protect
explosive materials against temperatures in excess of 150 degrees
Fahrenheit. This temperature threshold is based upon the 1992 Bureau of
Mines Information Circular No. 9335, Blasting Hazards of Gold Mining in
Sulfide-Bearing Ore Bodies; MSHA's Investigation Report No. D7431-S949,
Investigation of Premature Detonations, Paradise Peak Mine, (December
10, 1991); and the IME Safety Library Publication No. 4, ``Warnings and
Instructions for Consumers in Transporting, Storing, Handling and Using
Explosive Materials,'' (March 1992), all of which suggest a hazardous
change in stability of explosives once temperatures reach this level.
Final paragraph (b) of Secs. 56/57.6905, as proposed, requires that
explosive material be protected from impact except for tamping and
dropping during loading, so long as operators comply with existing
requirements of Secs. 56/57.6304 for primer protection. For example,
large equipment used during the loading process may be capable of
exerting forcible impact onto detonating or initiating systems. Also,
the proximity of other mining activity may allow equipment to come in
contact with explosive loading equipment and explosive containers,
thereby exerting impact.
In the proposal, MSHA would have added a new requirement for
underground mines to address the hazard of freeing hang-ups in raises,
chutes and ore passes. To allow for this type of blasting, the proposal
would have permitted only detonating cord to initiate explosives placed
in raises, chutes, and ore passes to free hang-ups.
Commenters objected to the proposal as being too restrictive in
that it would limit commonly accepted methods of blasting and prohibit
application of new technological developments. These commenters stated
that the use of
[[Page 36793]]
detonating cord as proposed by MSHA may introduce inherent hazards such
as fire from the ignition of timber, loosening timber, or other
supports, contributing to flyrock, and loosening rib and back. Although
MSHA's experience with detonating cord has not resulted in these
hazards, the rulemaking record does not contain sufficient support to
finalize the proposal. Therefore, the final rule does not adopt the
proposal and will continue to permit current conventional practices for
freeing hang-ups, provided applicable MSHA safety standards for
explosives are followed. These standards, including the requirements of
the final rule, provide reasonable protection against unplanned
detonation of explosives during hang-up blasting.
Sections 56/57.6313 Blast Site Security and Sections 56/57.6306
Loading, Blasting, and Security
The final regulations address the hazard of unplanned detonation of
explosives and the presence of unauthorized persons within the blast
site, as well as moving vehicles or electrically-powered equipment
which could contact and detonate explosive material. The final rule
also protects persons working in the blast site from other mining
activities unrelated to loading explosives, which can interfere with
the loading process and increase the likelihood of an accident.
Existing paragraph (a) of Secs. 56/57.6306 prohibits vehicles and
other equipment from being driven over explosive material or initiating
systems. Existing paragraph (b) allows haulage activity near the base
of the highwall being loaded, if no other haulage access exists. MSHA
has incorporated existing requirements of Secs. 56/57.6313 on blast
site security into final Secs. 56/57.6306(a). Existing Secs. 56/57.6313
require that areas in which loading is suspended or loaded holes are
awaiting firing must be attended, barricaded and posted, or flagged
against unauthorized entry. The proposal would have revised and
expanded application of existing Secs. 56/57.6313 by requiring that
when explosive materials or initiating systems are brought to the blast
site, operators must either barricade and post, or flag the blast site
so that unauthorized or inadvertent entry is prevented. Most commenters
agreed with the proposal. One commenter objected, however, suggesting
that MSHA require identification of the blast site only when the blast
site is not attended.
Final Secs. 56/57.6306(a) adopts the proposal and includes one
revision consistent with existing Secs. 56/57.6313 regarding attending
the blast site. Under the final standard, operators must either attend;
barricade and post the blast site with warning signs; or flag the blast
site against unauthorized entry. MSHA has included in the final
standard some common examples of the content of warning signs used in
the mining industry. In no way does the Agency intend for these
examples to be an exclusive list. Operators may use other warning signs
for compliance with this provision provided these signs adequately
convey to persons that they are entering a hazardous area. MSHA's
experience is that these warning signs are universally accepted and are
consistent with DOT placards for explosive materials. Once explosives
or initiating systems are brought to the blast site, good safety
practices dictate that precautions be taken to prevent accidental
damage to explosive materials, which can lead to a misfire or
accidental detonation. Key among these precautions is delineating the
blast site to warn unauthorized persons of the presence of explosives.
The provisions of Secs. 56/57.6313 were intended to require mine
operators to alert other persons working at the mine during loading and
blasting operations of the blast site parameters to prevent
unauthorized or inadvertent entry onto the blast site. Particularly on
a large blast site, persons performing blast-related tasks, such as
loading explosives, would not be readily able to warn persons to keep
out of the blast site.
One commenter stated that the proposal would result in additional
costs to purchase warning signs to barricade, post or flag the blast
site. MSHA anticipates that the final rule will result in only nominal
cost increases to the mining industry because the posting requirement
of final paragraph (a) is an incorporation of existing Secs. 56/
57.6313, as explained above. Moreover, the final regulation gives
operators compliance flexibility by providing alternative methods on
how to demarcate the blast site. Under this final regulation, once
initiation systems are brought to the blast site, mine operators must
either: (1) attend the blast site; (2) barricade and post the blast
site with warning signs, such as ``Danger,'' ``Explosives,'' or ``Keep
Out;''; or (3) flag the blast site, to be in compliance with paragraph
(a).
In the final rule, existing paragraph (a) of Secs. 56/57.6306
becomes paragraph (b) with no substantive change.
Paragraph (c) of final Secs. 56/57.6306 restates the existing rule
and restricts persons from entering the blast site except those engaged
in surveying, stemming, sampling of geology, and reopening of holes.
The final rule, like the proposal, clarifies that haulage activity is
permitted near the base of surface highwalls or underground bench faces
being loaded or awaiting firing, where no other haulage access exists.
Final paragraph (d) of Secs. 56/57.6306 protects against the hazard
of periods in which the process of loading and firing explosives is
interrupted. In the proposal, MSHA would have added new requirements
for all mines to address the potential hazards posed by unauthorized
personnel entering a blast site where explosive materials are present.
The preamble discussion to the proposed rule stated that persons
unfamiliar with the blast site may throw lighted smoking materials into
a blast hole, disturb the initiation system, or kick material into a
hole--any one of which could contribute to a premature detonation.
Existing paragraph (c) requires that loading be continuous except
where adverse circumstances beyond the operator's control necessitate
an interruption in loading. Existing paragraph (e) requires that when
loading is completed and circuits are connected, operators must blast
without undue delay, unless adverse circumstances exist which are
beyond the operator's control. The existing standard also requires that
operators notify MSHA if such delay could exceed 72-hours. Existing
paragraphs (c) and (e) of Secs. 56/57.6306 are deleted by the final
rule. Hazards addressed under these existing provisions are covered
under the final rule in paragraph (d).
Proposed paragraph (d)(1) would have required mine operators to
continue the loading and firing process without interruption or undue
delay. MSHA gave examples of ``undue delay'' in the preamble discussion
to the proposed standard which included emergencies, unfavorable
atmospheric conditions, shift changes and large equipment failures.
Also, the proposal would have required operators to attend the mine to
prevent unauthorized entry into the blast site.
Commenters indicated that the proposed ``attended'' requirement was
confusing because it could be read to suggest that the physical
presence of an individual at the blast site is necessary, contrary to
MSHA's definition of the term ``attended.'' Commenters also requested
that MSHA clarify the meaning of ``undue delay'' with a list of
circumstances. Other commenters suggested that MSHA clarify that
examples listed in the preamble to the proposed standard are not the
only justifications for an interruption in the
[[Page 36794]]
loading process. In addition, commenters objected to the proposal and
to the preamble discussion by stating that past practices in the mining
industry have successfully provided protection when loading was
interrupted or blasting was delayed, and that no injuries or deaths
have been attributed to unattended explosives.
MSHA agrees that there have been no known deaths caused by loaded
explosives awaiting blasting. However, explosives technology literature
and experience confirm that caution, including reasonable security
measures, are appropriate. The final rule therefore adopts an updated
version of a previous explosives safety regulation, and continues to
permit longstanding practices at larger mining operations which take
several days to complete the loading and blasting process.
Final paragraph (d) requires that operators conduct loading and
blasting in a manner to facilitate a continuous process so that the
blast is fired as soon as possible. The final standard does not retain
the concept of ``undue delay,'' but retains the existing requirement to
notify MSHA of blasting delays beyond 72 hours. The final standard does
not include the proposed requirement that the mine be attended when
loading is interrupted or blasting is delayed. MSHA believes that
requiring mine operators to load and blast as soon as practicable
provides the measure of protection needed for miners by minimizing the
loading and blasting exposure time.
Paragraph (d)(2) of Secs. 56/57.6306 of the proposed standard would
have required that persons securing a blast site at a surface mine or
at the surface area of an underground mine withdraw from the blast site
during the approach and progress of an electrical storm. The proposal
also would have required that persons securing an underground blast
site using an electrical blasting system that is capable of being
initiated by lightning be withdrawn to a safe location.
Commenters objected to this proposal by stating that it was
duplicative of existing Secs. 56/57.6604, which provides for the
suspension of blasting operations and the withdrawal of persons from
the blast area to a safe location during the approach and progress of
an electrical storm. MSHA agrees that Secs. 56/57.6604 sufficiently
addresses the precautions necessary to protect miners from the danger
of accidental detonation caused by an electrical storm. Therefore, the
final rule does not adopt proposed Secs. 56/57.6306.
Paragraphs (f) and (g) of the final rule are unchanged from the
existing regulations. These final rules continue to require that
operators institute specific safety measures immediately prior to and
after the blasting process. Final paragraph (f) requires, among other
things, ample warning, clear escape routes from the blast area, and all
access to the blast area to be guarded or barricaded to prevent the
passage of persons or vehicles. Numerous accidents have occurred from
the failure to clear or prevent unauthorized entry to the blast area.
Final paragraph (g) requires post-blast examinations to minimize
hazards to persons who will perform subsequent work in the area.
``EXTRANEOUS ELECTRICITY''
Sections 56/57.6602 Static Electricity Dissipation During Loading
This standard addresses the hazard resulting from a buildup of
static electricity generated by pneumatic loading, which could cause
premature detonation of explosives.
Existing Secs. 56/57.6602 require that when explosive material is
loaded pneumatically or dropped into a blasthole in a manner that could
generate static electricity, an evaluation must be made of potential
static electricity hazards and the hazard must be eliminated before
loading begins. The standard prohibits the use of wire-countered hoses
and plastic tube hole liners where their use could generate static
electricity in an amount sufficient to initiate a detonator.
Following publication of the existing rule, MSHA received technical
information from commenters suggesting that the scope of the standard
is too broad. The term ``dropping'' encompasses dropping, pouring, or
augering explosive materials into blastholes, activities which are
performed at a low velocity. As a result, insufficient static
electricity is generated to initiate a detonator, and therefore, does
not pose a serious hazard. In the proposal, MSHA narrowed the
application of this standard by deleting the term ``dropping'' from the
text of existing Secs. 56/57.6602.
In response to the proposed revision, a number of commenters
indicated that the rule would still include activities which would not
generate sufficient static electricity to initiate a detonator. These
commenters indicated that the amount of energy required to initiate a
detonator should be well-known by the blaster in charge and that
blaster is in the best position to make the determination as to when
precautions are necessary.
The final rule adopts this approach and requires that certain
precautions be taken only when there is a static electricity hazard.
IV. Executive Order 12866 and the Regulatory Flexibility Act
Executive Order 12866 requires that regulatory agencies assess both
the costs and benefits of intended regulations. MSHA has determined
that this rulemaking is not a significant regulatory action and,
therefore, has not prepared a separate analysis of costs and benefits.
The Regulatory Flexibility Act requires regulatory agencies to consider
a rule's impact on small entities. For the purpose of the Regulatory
Flexibility Analysis, MSHA defines a small entity as an operation
employing fewer than 20 employees. This final rule would not have a
significant economic impact on a substantial number of small entities.
The analysis contained in this preamble meets MSHA's responsibilities
under Executive Order 12866 and the Regulatory Flexibility Act.
Under the January 5, 1995, proposed rule (60 FR 1866), MSHA
estimated that the total annual recurring cost impact would have been
about $70,000. All of these costs were attributable to proposed
Secs. 56/57.6306(d)(1) which would have required the blast site to be
attended if loading was interrupted or firing of the blast was delayed
for any reason. MSHA recognizes that it is a safe practice to
continuously load explosives and fire them promptly; however,
interruptions in loading and delays in firing do occur, particularly in
large mining operations. This final rule, therefore, will retain the
existing requirements that permit reasonable interruptions in the
loading process and require notification to MSHA if blasting of a
loaded round will be delayed for more than 72 hours. MSHA estimates
that this provision affects fewer than 10 mines annually, but that the
mining industry will not incur any additional costs resulting from
MSHA's retention of the existing requirements.
The final rule eliminates existing Secs. 56/57.6313 and
incorporates these requirements for blast site security as Secs. 56/
57.6306(a) which require that the blast site be attended; barricaded
and posted with warning signs, such as ``Danger,'' ``Explosives,'' or
``Keep Out;'' or flagged against unauthorized entry, when explosives or
initiating systems are present. MSHA estimates that final Secs. 56/
57.6306(a) would affect about 15 small and 60 large mines annually.
MSHA anticipates that these provisions primarily would affect quarries;
open pit mines, except for certain operations which do not use
explosives, such as clay mines and phosphate mines; and large
underground mines. MSHA does
[[Page 36795]]
not expect small underground mines to be affected as these operations
would rarely, if ever, experience the need to leave the blast site
unattended when explosive materials or initiating systems are present.
Sand and gravel operations and mills rarely blast, and then the blast
site is likely to be a single charge, such as that needed to break a
large boulder.
Although the scope of this requirement is expanded from when
loading is suspended or firing is delayed to apply whenever explosive
materials or initiating systems are present at the blast site, MSHA
experience is that it is common industry practice to have the blast
site attended when explosive materials or initiating systems are
delivered and while loading is in progress. Final Secs. 56/57.6306(a)
address blast site security when explosives are being used. When
explosive materials or initiating systems are not being used, other
MSHA standards require that they be secured in magazines or other
appropriate explosive materials storage facilities. On occasion,
however, circumstances, such as delays in loading or firing, may
require the blast site to be left unattended when explosive materials
are present. In such situations, MSHA expects that mine operators would
choose to barricade and post with warning signs, such as ``Danger,''
``Explosives,'' or ``Keep Out,'' or flag the blast site against
unauthorized entry, rather than attend the blast site. One commenter
stated that the proposal would result in additional costs to purchase
warning signs to barricade, post, or flag the blast site. As this is
required under existing Secs. 56/57.6313, no new costs are required for
compliance with the final rule. MSHA, therefore, has not included an
additional cost for this provision in the Regulatory Flexibility
Analysis.
V. Unfunded Mandates Reform Act
Title II of the Unfunded Mandates Reform Act of 1995, Pub. L. 104-
4, requires each Federal agency to assess the effects of Federal
regulatory actions on state, local, and tribal governments and the
private sector, other than to the extent such actions merely
incorporate requirements specifically set forth in a statute. The
Agency has determined that this final rule does not impose an unfunded
mandate on state and local governments or tribal entities.
List of Subjects in 30 CFR Parts 56 and 57
Explosives, Incorporation by reference, Mine safety and health,
Reporting and recordkeeping requirements.
Dated: June 26, 1996.
J. Davitt McAteer,
Assistant Secretary for Mine Safety and Health.
Parts 56 and 57, subchapter N, chapter I, title 30 of the Code of
Federal Regulations are amended as follows:
PART 56--[AMENDED]
1. The authority citation for part 56 is revised to read as
follows:
Authority: 30 U.S.C. 811.
2. Effective September 10, 1996, subpart E of part 56 is revised to
read as follows:
Subpart E--Explosives
Sec.
56.6000 Definitions.
STORAGE
56.6100 Separation of stored explosive material.
56.6101 Areas around explosive material storage facilities.
56.6102 Explosive material storage practices.
56.6130 Explosive material storage facilities.
56.6131 Location of explosive material storage facilities.
56.6132 Magazine requirements.
56.6133 Powder chests.
TRANSPORTATION
56.6200 Delivery to storage or blast site areas.
56.6201 Separation of transported explosive material.
56.6202 Vehicles.
56.6203 Locomotives.
56.6204 Hoists.
56.6205 Conveying explosives by hand.
USE
56.6300 Control of blasting operations.
56.6301 Blasthole obstruction check.
56.6302 Separation of explosive material.
56.6303 Initiation preparation.
56.6304 Primer protection.
56.6305 Unused explosive material.
56.6306 Loading, blasting, and security.
56.6307 Drill stem loading.
56.6308 Initiation systems.
56.6309 Fuel oil requirements for ANFO.
56.6310 Misfire waiting period.
56.6311 Handling of misfires.
56.6312 Secondary blasting.
ELECTRIC BLASTING
56.6400 Compatibility of electric detonators.
56.6401 Shunting.
56.6402 Deenergized circuits near detonators.
56.6403 Branch circuits.
56.6404 Separation of blasting circuits from power source.
56.6405 Firing devices.
56.6406 Duration of current flow.
56.6407 Circuit testing.
NONELECTRIC BLASTING
56.6500 Damaged initiating material.
56.6501 Nonelectric initiation systems.
56.6502 Safety fuse.
EXTRANEOUS ELECTRICITY
56.6600 Loading practices.
56.6601 Grounding.
56.6602 Static electricity dissipation during loading.
56.6603 Air gap.
56.6604 Precautions during storms.
56.6605 Isolation of blasting circuits.
EQUIPMENT/TOOLS
56.6700 Nonsparking tools.
56.6701 Tamping and loading pole requirements.
MAINTENANCE
56.6800 Storage facilities.
56.6801 Vehicle repair.
56.6802 Bulk delivery vehicles.
56.6803 Blasting lines.
GENERAL REQUIREMENTS
56.6900 Damaged or deteriorated explosive material.
56.6901 Black powder.
56.6902 Excessive temperatures.
56.6903 Burning explosive material.
56.6904 Smoking and open flames.
57.6905 Protection of explosive material.
Subpart E--Explosives
Sec. 56.6000 Definitions.
The following definitions apply in this subpart.
Attended. Presence of an individual or continuous monitoring to
prevent unauthorized entry or access.
Barrier. A material object, or objects that separates, keeps apart,
or demarcates in a conspicuous manner such as cones, a warning sign, or
tape.
Blast area. The area in which concussion (shock wave), flying
material, or gases from an explosion may cause injury to persons. In
determining the blast area, the following factors shall be considered:
(1) Geology or material to be blasted.
(2) Blast pattern.
(3) Burden, depth, diameter, and angle of the holes.
(4) Blasting experience of the mine.
(5) Delay system, powder factor, and pounds per delay.
(6) Type and amount of explosive material.
(7) Type and amount of stemming.
Blast site. The area where explosive material is handled during
loading, including the perimeter formed by the loaded blastholes and 50
feet (15.2 meters) in all directions from loaded holes. A minimum
distance of 30 feet (9.1 meters) may replace the 50-foot (15.2-meter)
requirement if the perimeter of loaded holes is demarcated with a
barrier. The 50-foot (15.2-meter) and alternative 30-foot (9.1-meter)
[[Page 36796]]
requirements also apply in all directions along the full depth of the
hole.
Blasting agent. Any substance classified as a blasting agent by the
Department of Transportation in 49 CFR 173.114a(a). This document is
available at any MSHA Metal and Nonmetal Safety and Health district
office.
Detonating cord. A flexible cord containing a center core of high
explosives which may be used to initiate other explosives.
Detonator. Any device containing a detonating charge used to
initiate an explosive. These devices include electric or nonelectric
instantaneous or delay blasting caps and delay connectors. The term
``detonator'' does not include detonating cord. Detonators may be
either ``Class A'' detonators or ``Class C'' detonators, as classified
by the Department of Transportation in 49 CFR 173.53, and 173.100. This
document is available at any MSHA Metal and Nonmetal Safety and Health
district office.
Emulsion. An explosive material containing substantial amounts of
oxidizers dissolved in water droplets, surrounded by an immiscible
fuel.
Explosive. Any substance classified as an explosive by the
Department of Transportation in 49 CFR 173.53, 173.88, and 173.100.
This document is available at any MSHA Metal and Nonmetal Safety and
Health district office.
Explosive material. Explosives, blasting agents, and detonators.
Flash point. The minimum temperature at which sufficient vapor is
released by a liquid to form a flammable vapor-air mixture near the
surface of the liquid.
Igniter cord. A fuse that burns progressively along its length with
an external flame at the zone of burning, used for lighting a series of
safety fuses in a desired sequence.
Laminated partition. A partition composed of the following material
and minimum nominal dimensions: \1/2\-inch-thick plywood, \1/2\-inch-
thick gypsum wallboard, \1/8\-inch-thick low carbon steel, and \1/4\-
inch-thick plywood, bonded together in that order (IME-22 Box). A
laminated partition also includes alternative construction materials
described in the Institute of Makers of Explosives (IME) Safety Library
Publication No. 22, ``Recommendations for the Safe Transportation of
Detonators in a Vehicle with other Explosive Materials,'' (May 1993),
and the ``Generic Loading Guide for the IME-22 Container,'' (October
1993). This incorporation by reference has been approved by the
Director of the Federal Register in accordance with 5 U.S.C. 552(a) and
1 CFR part 51. Copies are available at MSHA, 4015 Wilson Boulevard,
Room 728, Arlington, VA 22203, and at all Metal and Nonmetal Mine
Safety and Health district offices, or available for inspection at the
Office of the Federal Register, 800 North Capitol Street, NW., 7th
Floor, suite 700, Washington, DC.
Loading. Placing explosive material either in a blasthole or
against the material to be blasted.
Magazine. A bullet-resistant, theft-resistant, fire-resistant,
weather-resistant, ventilated facility for the storage of explosives
and detonators (BATF Type 1 or Type 2 facility).
Misfire. The complete or partial failure of explosive material to
detonate as planned. The term also is used to describe the explosive
material itself that has failed to detonate.
Multipurpose dry-chemical fire extinguisher. An extinguisher having
a rating of at least 2-A:10-B:C and containing a nominal 4.5 pounds or
more of dry-chemical agent.
Primer. A unit, package, or cartridge of explosives which contains
a detonator and is used to initiate other explosives or blasting
agents.
Safety switch. A switch that provides shunt protection in blasting
circuits between the blast site and the switch used to connect a power
source to the blasting circuit.
Slurry. An explosive material containing substantial portions of a
liquid, oxidizers, and fuel, plus a thickener.
Storage facility. The entire class of structures used to store
explosive materials. A ``storage facility'' used to store blasting
agents corresponds to a BATF Type 4 or 5 storage facility.
Water gel. An explosive material containing substantial portions of
water, oxidizers, and fuel, plus a cross-linking agent.
STORAGE
Sec. 56.6100 Separation of stored explosive material.
(a) Detonators shall not be stored in the same magazine with other
explosive material.
(b) When stored in the same magazine, blasting agents shall be
separated from explosives, safety fuse, and detonating cord to prevent
contamination.
Sec. 56.6101 Areas around explosive material storage facilities.
(a) Areas surrounding storage facilities for explosive material
shall be clear of rubbish, brush, dry grass, and trees for 25 feet in
all directions, except that live trees 10 feet or taller need not be
removed.
(b) Other combustibles shall not be stored or allowed to accumulate
within 50 feet of explosive material. Combustible liquids shall be
stored in a manner that ensures drainage will occur away from the
explosive material storage facility in case of tank rupture.
Sec. 56.6102 Explosive material storage practices.
(a) Explosive material shall be--
(1) Stored in a manner to facilitate use of oldest stocks first;
(2) Stored according to brand and grade in such a manner as to
facilitate identification; and
(3) Stacked in a stable manner but not more than 8 feet high.
(b) Explosives and detonators shall be stored in closed
nonconductive containers except that nonelectric detonating devices may
be stored on nonconductive racks provided the case-insert instructions
and the date-plant-shift code are maintained with the product.
Sec. 56.6130 Explosive material storage facilities.
(a) Detonators and explosives shall be stored in magazines.
(b) Packaged blasting agents shall be stored in a magazine or other
facility which is ventilated to prevent dampness and excessive heating,
weather-resistant, and locked or attended. Drop trailers do not have to
be ventilated if they are currently licensed by the Federal, State, or
local authorities for over-the-road use. Facilities other than
magazines used to store blasting agents shall contain only blasting
agents.
(c) Bulk blasting agents shall be stored in weather-resistant bins
or tanks which are locked, attended, or otherwise inaccessible to
unauthorized entry.
(d) Facilities, bins or tanks shall be posted with the appropriate
United States Department of Transportation placards or other
appropriate warning signs that indicate the contents and are visible
from each approach.
Sec. 56.6131 Location of explosive material storage facilities.
(a) Storage facilities for any explosive material shall be--
(1) Located so that the forces generated by a storage facility
explosion will not create a hazard to occupants in mine buildings and
will not damage dams or electric substations; and
(2) Detached structures located outside the blast area and a
sufficient distance from powerlines so that the powerlines, if damaged,
would not contact the magazines.
[[Page 36797]]
(b) Operators should also be aware of regulations affecting storage
facilities in 27 CFR part 55, in particular, 27 CFR 55.218 and 55.220.
This document is available at any MSHA Metal and Nonmetal Safety and
Health district office.
Sec. 56.6132 Magazine requirements.
(a) Magazines shall be--
(1) Structurally sound;
(2) Noncombustible or the exterior covered with fire-resistant
material;
(3) Bullet resistant;
(4) Made of nonsparking material on the inside;
(5) Ventilated to control dampness and excessive heating within the
magazine;
(6) Posted with the appropriate United States Department of
Transportation placards or other appropriate warning signs that
indicate the contents and are visible from each approach, so located
that a bullet passing through any of the signs will not strike the
magazine;
(7) Kept clean and dry inside;
(8) Unlighted or lighted by devices that are specifically designed
for use in magazines and which do not create a fire or explosion
hazard;
(9) Unheated or heated only with devices that do not create a fire
or explosion hazard;
(10) Locked when unattended; and
(11) Used exclusively for the storage of explosive material except
for essential nonsparking equipment used for the operation of the
magazine.
(b) Metal magazines shall be equipped with electrical bonding
connections between all conductive portions so the entire structure is
at the same electrical potential. Suitable electrical bonding methods
include welding, riveting, or the use of securely tightened bolts where
individual metal portions are joined. Conductive portions of nonmetal
magazines shall be grounded.
(c) Electrical switches and outlets shall be located on the outside
of the magazine.
Sec. 56.6133 Powder chests.
(a) Powder chests (day boxes) shall be--
(1) Structurally sound, weather-resistant, equipped with a lid or
cover, and with only nonsparking material on the inside;
(2) Posted with the appropriate United States Department of
Transportation placards or other appropriate warning signs that
indicate the contents and are visible from each approach;
(3) Located out of the blast area once loading has been completed;
(4) Locked or attended when containing explosive material; and
(5) Emptied at the end of each shift with the contents returned to
a magazine or other storage facility, or attended.
(b) Detonators shall be kept in chests separate from explosives or
blasting agents, unless separated by 4-inches of hardwood or
equivalent, or a laminated partition. When a laminated partition is
used, operators must follow the provisions of the Institute of Makers
of Explosives (IME) Safety Library Publication No. 22,
``Recommendations for the Safe Transportation of Detonators in a
Vehicle with other Explosive Materials,'' (May 1993), and the ``Generic
Loading Guide for the IME-22 Container,'' (October 1993). This
incorporation by reference has been approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.
Copies are available at MSHA, 4015 Wilson Boulevard, Room 728,
Arlington, VA 22203, and at all Metal and Nonmetal Mine Safety and
Health district offices, or available for inspection at the Office of
the Federal Register, 800 North Capitol Street, NW., 7th Floor, suite
700, Washington, DC.
TRANSPORTATION
Sec. 56.6200 Delivery to storage or blast site areas.
Explosive material shall be transported without undue delay to the
storage area or blast site.
Sec. 56.6201 Separation of transported explosive material.
Detonators shall not be transported on the same vehicle or
conveyance with other explosives except as follows:
(a) Detonators in quantities of more than 1000 may be transported
in a vehicle or conveyance with explosives or blasting agents provided
the detonators are--
(1) Maintained in the original packaging as shipped from the
manufacturer; and
(2) Separated from explosives or blasting agents by 4-inches of
hardwood or equivalent, or a laminated partition. The hardwood or
equivalent shall be fastened to the vehicle or conveyance. When a
laminated partition is used, operators must follow the provisions of
the Institute of Makers of Explosives (IME) Safety Library Publication
No.22, ``Recommendations for the Safe Transportation of Detonators in a
Vehicle with other Explosive Materials,'' (May 1993), and the ``Generic
Loading Guide for the IME-22 Container,'' (October 1993). This
incorporation by reference has been approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.
Copies are available at MSHA, 4015 Wilson Boulevard, Room 728,
Arlington, VA 22203, and at all Metal and Nonmetal Mine Safety and
Health district offices, or available for inspection at the Office of
the Federal Register, 800 North Capitol Street, NW., 7th Floor, suite
700, Washington, DC.
(b) Detonators in quantities of 1000 or fewer may be transported
with explosives or blasting agents provided the detonators are--
(1) Kept in closed containers; and
(2) Separated from explosives or blasting agents by 4-inches of
hardwood or equivalent, or a laminated partition. The hardwood or
equivalent shall be fastened to the vehicle or conveyance. When a
laminated partition is used, operators must follow the provisions of
IME Safety Library Publication No. 22, ``Recommendations for the Safe
Transportation of Detonators in a Vehicle with other Explosive
Materials,'' (May 1993), and the ``Generic Loading Guide for the IME-22
Container,'' (October 1993). This incorporation by reference has been
approved by the Director of the Federal Register in accordance with 5
U.S.C. 552(a) and 1 CFR part 51. Copies are available at MSHA, 4015
Wilson Boulevard, Room 728, Arlington, VA 22203, and at all Metal and
Nonmetal Mine Safety and Health district offices, or available for
inspection at the Office of the Federal Register, 800 North Capitol
Street, NW., 7th Floor, suite 700, Washington, DC.
Sec. 56.6202 Vehicles.
(a) Vehicles containing explosive material shall be--
(1) Maintained in good condition and shall comply with the
requirements of subpart M of this part;
(2) Equipped with sides and enclosures higher than the explosive
material being transported or have the explosive material secured to a
nonconductive pallet;
(3) Equipped with a cargo space that shall contain the explosive
material (passenger areas shall not be considered cargo space);
(4) Equipped with at least two multipurpose dry-chemical fire
extinguishers or one such extinguisher and an automatic fire
suppression system;
(5) Posted with warning signs that indicate the contents and are
visible from each approach;
(6) Occupied only by persons necessary for handling the explosive
material;
[[Page 36798]]
(7) Attended or the cargo compartment locked, except when parked at
the blast site and loading is in progress; and
(8) Secured while parked by having--
(i) The brakes set;
(ii) The wheels chocked if movement could occur; and
(iii) The engine shut off unless powering a device being used in
the loading operation.
(b) Vehicles containing explosives shall have--
(1) No sparking material exposed in the cargo space; and
(2) Only properly secured nonsparking equipment in the cargo space
with the explosives.
(c) Vehicles used for dispensing bulk explosive material shall--
(1) Have no zinc or copper exposed in the cargo space; and
(2) Provide any enclosed screw-type conveyors with protection
against internal pressure and frictional heat.
Sec. 56.6203 Locomotives.
Explosive material shall not be transported on a locomotive. When
explosive material is hauled by trolley locomotive, covered,
electrically insulated cars shall be used.
Sec. 56.6204 Hoists.
(a) Before explosive material is transported in hoist conveyances,
the hoist operator shall be notified.
(b) Explosive material transported in hoist conveyances shall be
placed within a container which prevents shifting of the cargo that
could cause detonation of the container by impact or by sparks. The
manufacturer's container may be used if secured to a nonconductive
pallet. When explosives are transported, they shall be secured so as
not to contact any sparking material.
(c) No explosive material shall be transported during a mantrip.
Sec. 56.6205 Conveying explosives by hand.
Closed, nonconductive containers shall be used to carry explosives
and detonators to and from blast sites. Separate containers shall be
used for explosives and detonators.
USE
Sec. 56.6300 Control of blasting operations.
(a) Only persons trained and experienced in the handling and use of
explosive material shall direct blasting operations and related
activities.
(b) Trainees and inexperienced persons shall work only in the
immediate presence of persons trained and experienced in the handling
and use of explosive material.
Sec. 56.6301 Blasthole obstruction check.
Before loading, blastholes shall be checked and, wherever possible,
cleared of obstructions.
Sec. 56.6302 Separation of explosive material.
Explosives and blasting agents shall be kept separated from
detonators until loading begins.
Sec. 56.6303 Initiation preparation.
(a) Primers shall be made up only at the time of use and as close
to the blast site as conditions allow.
(b) Primers shall be prepared with the detonator contained securely
and completely within the explosive or contained securely and
appropriately for its design in the tunnel or cap well.
(c) When using detonating cord to initiate another explosive, a
connection shall be prepared with the detonating cord threaded through,
attached securely to, or otherwise in contact with the explosive.
Sec. 56.6304 Primer protection.
(a) Tamping shall not be done directly on a primer.
(b) Rigid cartridges of explosives or blasting agents that are 4
inches (100 millimeters) in diameter or larger shall not be dropped on
the primer except where the blasthole contains sufficient depth of
water to protect the primer from impact. Slit packages of prill, water
gel, or emulsions are not considered rigid cartridges and may be drop
loaded.
Sec. 56.6305 Unused explosive material.
Unused explosive material shall be moved to a protected location as
soon as practical after loading operations are completed.
Sec. 56.6306 Loading, blasting, and security.
(a) When explosive materials or initiating systems are brought to
the blast site, the blast site shall be attended; barricaded and posted
with warning signs, such as ``Danger,'' ``Explosives,'' or ``Keep
Out;'' or flagged against unauthorized entry.
(b) Vehicles and equipment shall not be driven over explosive
material or initiating systems in a manner which could contact the
material or systems, or create other hazards.
(c) Once loading begins, the only activities permitted within the
blast site shall be those activities directly related to the blasting
operation and the activities of surveying, stemming, sampling of
geology, and reopening of holes, provided that reasonable care is
exercised. Haulage activity is permitted near the base of a highwall
being loaded or awaiting firing, provided no other haulage access
exists.
(d) Loading and blasting shall be conducted in a manner designed to
facilitate a continuous process, with the blast fired as soon as
possible following the completion of loading. If blasting a loaded
round may be delayed for more than 72 hours, the operator shall notify
the appropriate MSHA district office.
(e) In electric blasting prior to connecting to the power source,
and in nonelectric blasting prior to attaching an initiating device,
all persons shall leave the blast area except persons in a blasting
shelter or other location that protects them from concussion (shock
wave), flying material, and gases.
(f) Before firing a blast--
(1) Ample warning shall be given to allow all persons to be
evacuated;
(2) Clear exit routes shall be provided for persons firing the
round; and
(3) All access routes to the blast area shall be guarded or
barricaded to prevent the passage of persons or vehicles.
(g) Work shall not resume in the blast area until a post-blast
examination addressing potential blast-related hazards has been
conducted by a person with the ability and experience to perform the
examination.
Sec. 56.6307 Drill stem loading.
Explosive material shall not be loaded into blastholes with drill
stem equipment or other devices that could be extracted while
containing explosive material. The use of loading hose, collar sleeves,
or collar pipes is permitted.
Sec. 56.6308 Initiation systems.
Initiation systems shall be used in accordance with the
manufacturer's instructions.
Sec. 56.6309 Fuel oil requirements for ANFO.
(a) Liquid hydrocarbon fuels with flash points lower than that of
No. 2 diesel oil (125 deg.F) shall not be used to prepare ammonium
nitrate-fuel oil, except that diesel fuels with flash points no lower
than 100 deg.F may be used at ambient air temperatures below 45
deg.F.
(b) Waste oil, including crankcase oil, shall not be used to
prepare ammonium nitrate-fuel oil.
Sec. 56.6310 Misfire waiting period.
When a misfire is suspected, persons shall not enter the blast
area--
(a) For 30 minutes if safety fuse and blasting caps are used; or
(b) For 15 minutes if any other type detonators are used.
Sec. 56.6311 Handling of misfires.
(a) Faces and muck piles shall be examined for misfires after each
blasting operation.
[[Page 36799]]
(b) Only work necessary to remove a misfire and protect the safety
of miners engaged in the removal shall be permitted in the affected
area until the misfire is disposed of in a safe manner.
(c) When a misfire cannot be disposed of safely, each approach to
the area affected by the misfire shall be posted with a warning sign at
a conspicuous location to prohibit entry, and the condition shall be
reported immediately to mine management.
(d) Misfires occurring during the shift shall be reported to mine
management not later than the end of the shift.
Sec. 56.6312 Secondary blasting.
Secondary blasts fired at the same time in the same work area shall
be initiated from one source.
ELECTRIC BLASTING
Sec. 56.6400 Compatibility of electric detonators.
All electric detonators to be fired in a round shall be from the
same manufacturer and shall have similar electrical firing
characteristics.
Sec. 56.6401 Shunting.
Except during testing--
(a) Electric detonators shall be kept shunted until connected to
the blasting line or wired into a blasting round;
(b) Wired rounds shall be kept shunted until connected to the
blasting line; and
(c) Blasting lines shall be kept shunted until immediately before
blasting.
Sec. 56.6402 Deenergized circuits near detonators.
Electrical distribution circuits within 50 feet of electric
detonators at the blast site shall be deenergized. Such circuits need
not be deenergized between 25 to 50 feet of the electric detonators if
stray current tests, conducted as frequently as necessary, indicate a
maximum stray current of less than 0.05 amperes through a 1-ohm
resistor as measured at the blast site.
Sec. 56.6403 Branch circuits.
(a) If electric blasting includes the use of branch circuits, each
branch shall be equipped with a safety switch or equivalent method to
isolate the circuits to be used.
(b) At least one safety switch or equivalent method of protection
shall be located outside the blast area and shall be in the open
position until persons are withdrawn.
Sec. 56.6404 Separation of blasting circuits from power source.
(a) Switches used to connect the power source to a blasting circuit
shall be locked in the open position except when closed to fire the
blast.
(b) Lead wires shall not be connected to the blasting switch until
the shot is ready to be fired.
Sec. 56.6405 Firing devices.
(a) Power sources shall be capable of delivering sufficient current
to energize all electric detonators to be fired with the type of
circuits used. Storage or dry cell batteries are not permitted as power
sources.
(b) Blasting machines shall be tested, repaired, and maintained in
accordance with manufacturer's instructions.
(c) Only the blaster shall have the key or other control to an
electrical firing device.
Sec. 56.6406 Duration of current flow.
If any part of a blast is connected in parallel and is to be
initiated from powerlines or lighting circuits, the time of current
flow shall be limited to a maximum of 25 milliseconds. This can be
accomplished by incorporating an arcing control device in the blasting
circuit or by interrupting the circuit with an explosive device
attached to one or both lead lines and initiated by a 25-millisecond
delay electric detonator.
Sec. 56.6407 Circuit testing.
A blasting galvanometer or other instrument designed for testing
blasting circuits shall be used to test each of the following:
(a) Continuity of each electric detonator in the blasthole prior to
stemming and connection to the blasting line.
(b) Resistance of individual series or the resistance of multiple
balanced series to be connected in parallel prior to their connection
to the blasting line.
(c) Continuity of blasting lines prior to the connection of
electric detonator series.
(d) Total blasting circuit resistance prior to connection to the
power source.
NONELECTRIC BLASTING
Sec. 56.6500 Damaged initiating material.
A visual check of the completed circuit shall be made to ensure
that the components are properly aligned and connected. Safety fuse,
igniter cord, detonating cord, shock or gas tubing, and similar
material which is kinked, bent sharply, or damaged shall not be used.
Sec. 56.6501 Nonelectric initiation systems.
(a) When the nonelectric initiation system uses shock tube--
(1) Connections with other initiation devices shall be secured in a
manner which provides for uninterrupted propagation;
(2) Factory-made units shall be used as assembled and shall not be
cut except that a single splice is permitted on the lead-in trunkline
during dry conditions; and
(3) Connections between blastholes shall not be made until
immediately prior to clearing the blast site when surface delay
detonators are used.
(b) When the nonelectric initiation system uses detonating cord--
(1) The line of detonating cord extending out of a blasthole shall
be cut from the supply spool immediately after the attached explosive
is correctly positioned in the hole;
(2) In multiple row blasts, the trunkline layout shall be designed
so that the detonation can reach each blasthole from at least two
directions;
(3) Connections shall be tight and kept at right angles to the
trunkline;
(4) Detonators shall be attached securely to the side of the
detonating cord and pointed in the direction in which detonation is to
proceed;
(5) Connections between blastholes shall not be made until
immediately prior to clearing the blast site when surface delay
detonators are used; and
(6) Lead-in lines shall be manually unreeled if connected to the
trunklines at the blast site.
(c) When the nonelectric initiation system uses gas tube,
continuity of the circuit shall be tested prior to blasting.
Sec. 56.6502 Safety fuse.
(a) The burning rate of each spool of safety fuse to be used shall
be measured, posted in locations which will be conspicuous to safety
fuse users, and brought to the attention of all persons involved with
the blasting operation.
(b) When firing with safety fuse ignited individually using
handheld lighters, the safety fuse shall be of lengths which provide at
least the minimum burning time for a particular size round, as
specified in the following table:
Table E-1.--Safety Fuse--Minimum Burning Time
------------------------------------------------------------------------
Number of holes in a round Minimum burning time
------------------------------------------------------------------------
1...................................... 2 min.\1\
2-5.................................... 2 min. 40 sec.
6-10................................... 3 min. 20 sec.
11 to 15............................... 5 min.
------------------------------------------------------------------------
\1\ For example, at least a 36-inch length of 40-second-per-foot safety
fuse or at least a 48-inch length of 30-second-per-foot safety fuse
would have to be used to allow sufficient time to evacuate the area.
[[Page 36800]]
(c) Where flyrock might damage exposed safety fuse, the blast shall
be timed so that all safety fuses are burning within the blastholes
before any blasthole detonates.
(d) Fuse shall be cut and capped in dry locations.
(e) Blasting caps shall be crimped to fuse only with implements
designed for that purpose.
(f) Safety fuse shall be ignited only after the primer and the
explosive material are securely in place.
(g) Safety fuse shall be ignited only with devices designed for
that purpose. Carbide lights, liquefied petroleum gas torches, and
cigarette lighters shall not be used to light safety fuse.
(h) At least two persons shall be present when lighting safety
fuse, and no one shall light more than 15 individual fuses. If more
than 15 holes per person are to be fired, electric initiation systems,
igniter cord and connectors, or other nonelectric initiation systems
shall be used.
EXTRANEOUS ELECTRICITY
Sec. 56.6600 Loading practices.
If extraneous electricity is suspected in an area where electric
detonators are used, loading shall be suspended until tests determine
that stray current does not exceed 0.05 amperes through a 1-ohm
resister when measured at the location of the electric detonators. If
greater levels of extraneous electricity are found, the source shall be
determined and no loading shall take place until the condition is
corrected.
Sec. 56.6601 Grounding.
Electric blasting circuits, including powerline sources when used,
shall not be grounded.
Sec. 56.6602 Static electricity dissipation during loading.
When explosive material is loaded pneumatically into a blasthole in
a manner that generates a static electricity hazard--
(a) An evaluation of the potential static electricity hazard shall
be made and any hazard shall be eliminated before loading begins;
(b) The loading hose shall be of a semiconductive type, have a
total of not more than 2 megohms of resistance over its entire length
and not less than 1000 ohms of resistance per foot;
(c) Wire-countered hoses shall not be used;
(d) Conductive parts of the loading equipment shall be bonded and
grounded and grounds shall not be made to other potential sources of
extraneous electricity; and
(e) Plastic tubes shall not be used as hole liners if the hole
contains an electric detonator.
Sec. 56.6603 Air gap.
At least a 15-foot air gap shall be provided between the blasting
circuit and the electric power source.
Sec. 56.6604 Precautions during storms.
During the approach and progress of an electrical storm, blasting
operations shall be suspended and persons withdrawn from the blast area
or to a safe location.
Sec. 56.6605 Isolation of blasting circuits.
Lead wires and blasting lines shall be isolated and insulated from
power conductors, pipelines, and railroad tracks, and shall be
protected from sources of stray or static electricity. Blasting
circuits shall be protected from any contact between firing lines and
overhead powerlines which could result from the force of a blast.
EQUIPMENT/TOOLS
Sec. 56.6700 Nonsparking tools.
Only nonsparking tools shall be used to open containers of
explosive material or to punch holes in explosive cartridges.
Sec. 56.6701 Tamping and loading pole requirements.
Tamping and loading poles shall be of wood or other nonconductive,
nonsparking material. Couplings for poles shall be nonsparking.
MAINTENANCE
Sec. 56.6800 Storage facilities.
When repair work which could produce a spark or flame is to be
performed on a storage facility--
(a) The explosive material shall be moved to another facility, or
moved at least 50 feet from the repair activity and monitored; and
(b) The facility shall be cleaned to prevent accidental detonation.
Sec. 56.6801 Vehicle repair.
Vehicles containing explosive material and oxidizers shall not be
taken into a repair garage or shop.
Sec. 56.6802 Bulk delivery vehicles.
No welding or cutting shall be performed on a bulk delivery vehicle
until the vehicle has been washed down and all explosive material has
been removed. Before welding or cutting on a hollow shaft, the shaft
shall be thoroughly cleaned inside and out and vented with a minimum
\1/2\-inch diameter opening to allow for sufficient ventilation.
Sec. 56.6803 Blasting lines.
Permanent blasting lines shall be properly supported. All blasting
lines shall be insulated and kept in good repair.
GENERAL REQUIREMENTS
Sec. 56.6900 Damaged or deteriorated explosive material.
Damaged or deteriorated explosive material shall be disposed of in
a safe manner in accordance with the instructions of the manufacturer.
Sec. 56.6901 Black powder.
(a) Black powder shall be used for blasting only when a desired
result cannot be obtained with another type of explosive, such as in
quarrying certain types of dimension stone.
(b) Containers of black powder shall be--
(1) Nonsparking;
(2) Kept in a totally enclosed cargo space while being transported
by a vehicle;
(3) Securely closed at all times when--
(i) Within 50 feet of any magazine or open flame;
(ii) Within any building in which a fuel-fired or exposed-element
electric heater is operating; or
(iii) In an area where electrical or incandescent-particle sparks
could result in powder ignition; and
(4) Opened only when the powder is being transferred to a blasthole
or another container and only in locations not listed in paragraph
(b)(3) of this section.
(c) Black powder shall be transferred from containers only by
pouring.
(d) Spills shall be cleaned up promptly with nonsparking equipment.
Contaminated powder shall be put into a container of water and shall be
disposed of promptly after the granules have disintegrated, or the
spill area shall be flushed promptly with water until the granules have
disintegrated completely.
(e) Misfires shall be disposed of by washing the stemming and
powder charge from the blasthole, and removing and disposing of the
initiator in accordance with the requirement for damaged explosives.
(f) Holes shall not be reloaded for at least 12 hours when the
blastholes have failed to break as planned.
Sec. 56.6902 Excessive temperatures.
(a) Where heat could cause premature detonation, explosive material
shall not be loaded into hot areas, such as kilns or sprung holes.
(b) When blasting sulfide ores where hot holes occur that may react
with
[[Page 36801]]
explosive material in blastholes, operators shall--
(1) Measure an appropriate number of blasthole temperatures in
order to assess the specific mine conditions prior to the introduction
of explosive material;
(2) Limit the time between the completion of loading and the
initiation of the blast to no more than 12 hours; and
(3) Take other special precautions to address the specific
conditions at the mine to prevent premature detonation.
Sec. 56.6903 Burning explosive material.
If explosive material is suspected of burning at the blast site,
persons shall be evacuated from the endangered area and shall not
return for at least one hour after the burning or suspected burning has
stopped.
Sec. 56.6904 Smoking and open flames.
Smoking and use of open flames shall not be permitted within 50
feet of explosive material except when separated by permanent
noncombustible barriers. This standard does not apply to devices
designed to ignite safety fuse or to heating devices which do not
create a fire or explosion hazard.
Sec. 56.6905 Protection of explosive material.
(a) Explosive material shall be protected from temperatures in
excess of 150 degrees Fahrenheit.
(b) Explosive material shall be protected from impact, except for
tamping and dropping during loading.
PART 57--[AMENDED]
1. The authority citation for part 57 is revised to read as
follows:
Authority: 30 U.S.C. 811.
2. Effective September 10, 1996, subpart E of part 57 is revised to
read as follows:
Subpart E--Explosives
Sec.
57.6000 Definitions.
STORAGE--SURFACE AND UNDERGROUND
57.6100 Separation of stored explosive material.
57.6101 Areas around explosive material storage facilities.
57.6102 Explosive material storage practices.
STORAGE--SURFACE ONLY
57.6130 Explosive material storage facilities.
57.6131 Location of explosive material storage facilities.
57.6132 Magazine requirements.
57.6133 Powder chests.
STORAGE--UNDERGROUND ONLY
57.6160 Main facilities.
57.6161 Auxiliary facilities.
TRANSPORTATION--SURFACE AND UNDERGROUND
57.6200 Delivery to storage or blast site areas.
57.6201 Separation of transported explosive material.
57.6202 Vehicles.
57.6203 Locomotives.
57.6204 Hoists.
57.6205 Conveying explosives by hand.
USE--SURFACE AND UNDERGROUND
57.6300 Control of blasting operations.
57.6301 Blasthole obstruction check.
57.6302 Separation of explosive material.
57.6303 Initiation preparation.
57.6304 Primer protection.
57.6305 Unused explosive material.
57.6306 Loading, blasting, and security.
57.6307 Drill stem loading.
57.6308 Initiation systems.
57.6309 Fuel oil requirements for ANFO.
57.6310 Misfire waiting period.
57.6311 Handling of misfires.
57.6312 Secondary blasting.
ELECTRIC BLASTING--SURFACE AND UNDERGROUND
57.6400 Compatibility of electric detonators.
57.6401 Shunting.
57.6402 Deenergized circuits near detonators.
57.6403 Branch circuits.
57.6404 Separation of blasting circuits from power source.
57.6405 Firing devices.
57.6406 Duration of current flow.
57.6407 Circuit testing.
NONELECTRIC BLASTING--SURFACE AND UNDERGROUND
57.6500 Damaged initiating material.
57.6501 Nonelectric initiation systems.
57.6502 Safety fuse.
EXTRANEOUS ELECTRICITY--SURFACE AND UNDERGROUND
57.6600 Loading practices.
57.6601 Grounding.
57.6602 Static electricity dissipation during loading.
57.6603 Air gap.
57.6604 Precautions during storms.
57.6605 Isolation of blasting circuits.
EQUIPMENT/TOOLS--SURFACE AND UNDERGROUND
57.6700 Nonsparking tools.
57.6701 Tamping and loading pole requirements.
MAINTENANCE--SURFACE AND UNDERGROUND
57.6800 Storage facilities.
57.6801 Vehicle repair.
57.6802 Bulk delivery vehicles.
57.6803 Blasting lines.
GENERAL REQUIREMENTS--SURFACE AND UNDERGROUND
57.6900 Damaged or deteriorated explosive material.
57.6901 Black powder.
57.6902 Excessive temperatures.
57.6903 Burning explosive material.
57.6904 Smoking and open flames.
57.6905 Protection of explosive material.
GENERAL REQUIREMENTS--UNDERGROUND ONLY
57.6960 Mixing of explosive material.
Subpart E--Explosives
Sec. 57.6000 Definitions.
The following definitions apply in this subpart.
Attended. Presence of an individual or continuous monitoring to
prevent unauthorized entry or access. In addition, areas containing
explosive material at underground areas of a mine can be considered
attended when all access to the underground areas of the mine is
secured from unauthorized entry. Vertical shafts shall be considered
secure. Inclined shafts or adits shall be considered secure when locked
at the surface.
Barrier. A material object, or objects that separates, keeps apart,
or demarcates in a conspicuous manner such as cones, a warning sign, or
tape.
Blast area. The area in which concussion (shock wave), flying
material, or gases from an explosion may cause injury to persons. In
determining the blast area, the following factors shall be considered:
(1) Geology or material to be blasted.
(2) Blast pattern.
(3) Burden, depth, diameter, and angle of the holes.
(4) Blasting experience of the mine.
(5) Delay system, powder factor, and pounds per delay.
(6) Type and amount of explosive material.
(7) Type and amount of stemming.
Blast site. The area where explosive material is handled during
loading, including the perimeter formed by the loaded blastholes and 50
feet (15.2 meters) in all directions from loaded holes. A minimum
distance of 30 feet (9.1 meters) may replace the 50-foot (15.2-meter)
requirement if the perimeter of loaded holes is demarcated with a
barrier. The 50-foot (15.2-meter) and alternative 30-foot (9.1-meter)
requirements also apply in all directions along the full depth of the
hole. In underground mines, at least 15 feet (4.6 meters) of solid rib,
pillar, or broken rock can be substituted for the 50-foot (15.2-meter)
distance. In underground mines utilizing a block-caving system or
similar system, at least 6 feet (1.8 meters) of solid rib or pillar,
including concrete reinforcement of at least 10 inches (254
millimeters), with overall dimensions of not less than 6 feet (1.8
meters), may be substituted for the 50-foot (15.2-meter) distance
requirement.
Blasting agent. Any substance classified as a blasting agent by the
Department of Transportation in 49 CFR
[[Page 36802]]
173.114a(a). This document is available at any MSHA Metal and Nonmetal
Safety and Health district office.
Detonating cord. A flexible cord containing a center core of high
explosives which may be used to initiate other explosives.
Detonator. Any device containing a detonating charge used to
initiate an explosive. These devices include electric or nonelectric
instantaneous or delay blasting caps, and delay connectors. The term
``detonator'' does not include detonating cord. Detonators may be
either ``Class A'' detonators or ``Class C'' detonators, as classified
by the Department of Transportation in 49 CFR 173.53, and 173.100. This
document is available at any MSHA Metal and Nonmetal Safety and Health
district office.
Emulsion. An explosive material containing substantial amounts of
oxidizers dissolved in water droplets, surrounded by an immiscible
fuel.
Explosive. Any substance classified as an explosive by the
Department of Transportation in 49 CFR 173.53, 173.88, and 173.100.
This document is available at any MSHA Metal and Nonmetal Safety and
Health district office.
Explosive material. Explosives, blasting agents, and detonators.
Flash point. The minimum temperature at which sufficient vapor is
released by a liquid to form a flammable vapor-air mixture near the
surface of the liquid.
Igniter cord. A fuse that burns progressively along its length with
an external flame at the zone of burning, used for lighting a series of
safety fuses in a desired sequence.
Laminated partition. A partition composed of the following material
and minimum nominal dimensions: \1/2\-inch-thick plywood, \1/2\-inch-
thick gypsum wallboard, \1/8\-inch-thick low carbon steel, and \1/4\-
inch-thick plywood, bonded together in that order (IME-22 Box). A
laminated partition also includes alternative construction materials
described in the Institute of Makers of Explosives (IME) Safety Library
Publication No. 22, ``Recommendations for the Safe Transportation of
Detonators in a Vehicle with other Explosive Materials.'' (May 1993),
and the ``Generic Loading Guide for the IME-22 Container,'' (October
1993). This incorporation by reference has been approved by the
Director of the Federal Register in accordance with 5 U.S.C. 552(a) and
1 CFR part 51. Copies are available at MSHA, 4015 Wilson Boulevard,
Room 728, Arlington, VA 22203, and at all Metal and Nonmetal Mine
Safety and Health district offices, or available for inspection at the
Office of the Federal Register, 800 North Capitol Street NW., 7th
Floor, suite 700, Washington, DC.
Loading. Placing explosive material either in a blasthole or
against the material to be blasted.
Magazine. A bullet-resistant, theft-resistant, fire-resistant,
weather-resistant, ventilated facility for the storage of explosives
and detonators (BATF Type 1 or Type 2 facility).
Misfire. The complete or partial failure of explosive material to
detonate as planned. The term also is used to describe the explosive
material itself that has failed to detonate.
Multipurpose dry-chemical fire extinguisher. An extinguisher having
a rating of at least 2-A:10-B:C and containing a nominal 4.5 pounds or
more of dry-chemical agent.
Primer. A unit, package, or cartridge of explosives which contains
a detonator and is used to initiate other explosives or blasting
agents.
Safety switch. A switch that provides shunt protection in blasting
circuits between the blast site and the switch used to connect a power
source to the blasting circuit.
Slurry. An explosive material containing substantial portions of a
liquid, oxidizers, and fuel, plus a thickener.
Storage facility. The entire class of structures used to store
explosive materials. A ``storage facility'' used to store blasting
agents corresponds to a BATF Type 4 or 5 storage facility.
Water gel. An explosive material containing substantial portions of
water, oxidizers, and fuel, plus a cross-linking agent.
STORAGE--SURFACE AND UNDERGROUND
Sec. 57.6100 Separation of stored explosive material.
(a) Detonators shall not be stored in the same magazine with other
explosive material.
(b) When stored in the same magazine, blasting agents shall be
separated from explosives, safety fuse, and detonating cord to prevent
contamination.
Sec. 57.6101 Areas around explosive material storage facilities.
(a) Areas surrounding storage facilities for explosive material
shall be clear of rubbish, brush, dry grass, and trees for 25 feet in
all directions, except that live trees 10 feet or taller need not be
removed.
(b) Other combustibles shall not be stored or allowed to accumulate
within 50 feet of explosive material. Combustible liquids shall be
stored in a manner that ensures drainage will occur away from the
explosive material storage facility in case of tank rupture.
Sec. 57.6102 Explosive material storage practices.
(a) Explosive material shall be--
(1) Stored in a manner to facilitate use of oldest stocks first;
(2) Stored according to brand and grade in such a manner as to
facilitate identification; and
(3) Stacked in a stable manner but not more than 8 feet high.
(b) Explosives and detonators shall be stored in closed
nonconductive containers except that nonelectric detonating devices may
be stored on nonconductive racks provided the case-insert instructions
and the date-plant-shift code are maintained with the product.
STORAGE--SURFACE ONLY
Sec. 57.6130 Explosive material storage facilities.
(a) Detonators and explosives shall be stored in magazines.
(b) Packaged blasting agents shall be stored in a magazine or other
facility which is ventilated to prevent dampness and excessive heating,
weather-resistant, and locked or attended. Drop trailers do not have to
be ventilated if they are currently licensed by the Federal, State, or
local authorities for over-the-road use. Facilities other than
magazines used to store blasting agents shall contain only blasting
agents.
(c) Bulk blasting agents shall be stored in weather-resistant bins
or tanks which are locked, attended, or otherwise inaccessible to
unauthorized entry.
(d) Facilities, bins or tanks shall be posted with the appropriate
United States Department of Transportation placards or other
appropriate warning signs that indicate the contents and are visible
from each approach.
Sec. 57.6131 Location of explosive material storage facilities.
(a) Storage facilities for any explosive material shall be--
(1) Located so that the forces generated by a storage facility
explosion will not create a hazard to occupants in mine buildings and
will not damage dams or electric substations; and
(2) Detached structures located outside the blast area and a
sufficient distance from powerlines so that the powerlines, if damaged,
would not contact the magazines.
(b) Operators should also be aware of regulations affecting storage
facilities in 27 CFR part 55, in particular, 27 CFR
[[Page 36803]]
55.218 and 55.220. This document is available at any MSHA Metal and
Nonmetal Safety and Health district office.
Sec. 57.6132 Magazine requirements.
(a) Magazines shall be--
(1) Structurally sound;
(2) Noncombustible or the exterior covered with fire-resistant
material;
(3) Bullet resistant;
(4) Made of nonsparking material on the inside;
(5) Ventilated to control dampness and excessive heating within the
magazine;
(6) Posted with the appropriate United States Department of
Transportation placards or other appropriate warning signs that
indicate the contents and are visible from each approach, so located
that a bullet passing through any of the signs will not strike the
magazine;
(7) Kept clean and dry inside;
(8) Unlighted or lighted by devices that are specifically designed
for use in magazines and which do not create a fire or explosion
hazard;
(9) Unheated or heated only with devices that do not create a fire
or explosion hazard;
(10) Locked when unattended; and
(11) Used exclusively for the storage of explosive material except
for essential nonsparking equipment used for the operation of the
magazine.
(b) Metal magazines shall be equipped with electrical bonding
connections between all conductive portions so the entire structure is
at the same electrical potential. Suitable electrical bonding methods
include welding, riveting, or the use of securely tightened bolts where
individual metal portions are joined. Conductive portions of nonmetal
magazines shall be grounded.
(c) Electrical switches and outlets shall be located on the outside
of the magazine.
Sec. 57.6133 Powder chests.
(a) Powder chests (day boxes) shall be--
(1) Structurally sound, weather-resistant, equipped with a lid or
cover, and with only nonsparking material on the inside;
(2) Posted with the appropriate United States Department of
Transportation placards or other appropriate warning signs that
indicate the contents and are visible from each approach;
(3) Located out of the blast area once loading has been completed;
(4) Locked or attended when containing explosive material; and
(5) Emptied at the end of each shift with the contents returned to
a magazine or other storage facility, or attended.
(b) Detonators shall be kept in chests separate from explosives or
blasting agents, unless separated by 4-inches of hardwood or
equivalent, or a laminated partition. When a laminated partition is
used, operators must follow the provisions of the Institute of Makers
of Explosives (IME) Safety Library Publication No. 22, (May 1993),
``Recommendations for the Safe Transportation of Detonators in a
Vehicle with other Explosive Materials,'' (May 1993), and the ``Generic
Loading Guide for the IME-22 Container,'' (October 1993). This
incorporation by reference has been approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.
Copies are available at MSHA, 4015 Wilson Boulevard, Room 728,
Arlington, VA 22203, and at all Metal and Nonmetal Mine Safety and
Health district offices, or available for inspection at the Office of
the Federal Register, 800 North Capitol Street NW., 7th Floor, suite
700, Washington, DC.
STORAGE--UNDERGROUND ONLY
Sec. 57.6160 Main facilities.
(a) Main facilities used to store explosive material underground
shall be located--
(1) In stable or supported ground;
(2) So that a fire or explosion in the storage facilities will not
prevent escape from the mine, or cause detonation of the contents of
another storage facility;
(3) Out of the line of blasts, and protected from vehicular
traffic, except that accessing the facility;
(4) At least 200 feet from work places or shafts;
(5) At least 50 feet from electric substations;
(6) A safe distance from trolley wires; and
(7) At least 25 feet from detonator storage facilities.
(b) Main facilities used to store explosive material underground
shall be--
(1) Posted with warning signs that indicate the contents and are
visible from any approach;
(2) Used exclusively for the storage of explosive material and
necessary equipment associated with explosive material storage and
delivery:
(i) Portions of the facility used for the storage of explosives
shall only contain nonsparking material or equipment.
(ii) The blasting agent portion of the facility may be used for the
storage of other necessary equipment;
(3) Kept clean, suitably dry, and orderly;
(4) Provided with unobstructed ventilation openings;
(5) Kept securely locked unless all access to the mine is either
locked or attended; and
(6) Unlighted or lighted only with devices that do not create a
fire or explosion hazard and which are specifically designed for use in
magazines.
(c) Electrical switches and outlets shall be located outside the
facility.
Sec. 57.6161 Auxiliary facilities.
(a) Auxiliary facilities used to store explosive material near work
places shall be wooden, box-type containers equipped with covers or
doors, or facilities constructed or mined-out to provide equivalent
impact resistance and confinement.
(b) The auxiliary facilities shall be--
(1) Constructed of nonsparking material on the inside when used for
the storage of explosives;
(2) Kept clean, suitably dry, and orderly;
(3) Kept in repair;
(4) Located out of the line of blasts so they will not be subjected
to damaging shock or flyrock;
(5) Identified with warning signs or coded to indicate the contents
with markings visible from any approach;
(6) Located at least 15 feet from all haulageways and electrical
equipment, or placed entirely within a mined-out recess in the rib used
exclusively for explosive material;
(7) Filled with no more than a one-week supply of explosive
material;
(8) Separated by at least 25 feet from other facilities used to
store detonators; and
(9) Kept securely locked unless all access to the mine is either
locked or attended.
TRANSPORTATION--SURFACE AND UNDERGROUND
Sec. 57.6200 Delivery to storage or blast site areas.
Explosive material shall be transported without undue delay to the
storage area or blast site.
Sec. 57.6201 Separation of transported explosive material.
Detonators shall not be transported on the same vehicle or
conveyance with other explosives except as follows:
(a) Detonators in quantities of more than 1,000 may be transported
in a vehicle or conveyance with explosives or blasting agents provided
the detonators are--
(1) Maintained in the original packaging as shipped from the
manufacturer; and
[[Page 36804]]
(2) Separated from explosives or blasting agents by 4 inches of
hardwood or equivalent, or a laminated partition. The hardwood or
equivalent shall be fastened to the vehicle or conveyance. When a
laminated partition is used, operators must follow the provisions of
the Institute of Makers of Explosives (IME) Safety Library Publication
No. 22, ``Recommendations for the Safe Transportation of Detonators in
a Vehicle with other Explosive Materials'' (May 1993), and the
``Generic Loading Guide for the IME-22 Container'' (October 1993). This
incorporation by reference has been approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.
Copies are available at MSHA, 4015 Wilson Boulevard, Room 728,
Arlington, VA 22203, and at all Metal and Nonmetal Mine Safety and
Health district offices, or available for examination at the Office of
the Federal Register, 800 North Capitol Street NW., 7th Floor, suite
700, Washington, DC.
(b) Detonators in quantities of 1,000 or fewer may be transported
with explosives or blasting agents provided the detonators are--
(1) Kept in closed containers; and
(2) Separated from explosives or blasting agents by 4 inches of
hardwood or equivalent, or a laminated partition. The hardwood or
equivalent shall be fastened to the vehicle or conveyance. When a
laminated partition is used, operators must follow the provisions of
IME Safety Library Publication No. 22, ``Recommendations for the Safe
Transportation of Detonators in a Vehicle with other Explosive
Materials'' (May 1993), and the ``Generic Loading Guide for the IME-22
Container'' (October 1993). This incorporation by reference has been
approved by the Director of the Federal Register in accordance with 5
U.S.C. 552(a) and 1 CFR part 51. Copies are available at MSHA, 4015
Wilson Boulevard, Room 728, Arlington, VA 22203, and at all Metal and
Nonmetal Mine Safety and Health district offices, or available for
examination at the Office of the Federal Register, 800 North Capitol
Street NW., 7th Floor, suite 700, Washington, DC.
Sec. 57.6202 Vehicles.
(a) Vehicles containing explosive material shall be--
(1) Maintained in good condition and shall comply with the
requirements of subpart M of this part;
(2) Equipped with sides and enclosures higher than the explosive
material being transported or have the explosive material secured to a
nonconductive pallet;
(3) Equipped with a cargo space that shall contain the explosive
material (passenger areas shall not be considered cargo space);
(4) Equipped with at least two multipurpose dry-chemical fire
extinguishers or one such extinguisher and an automatic fire
suppression system;
(5) Posted with warning signs that indicate the contents and are
visible from each approach;
(6) Occupied only by persons necessary for handling the explosive
material;
(7) Attended or the cargo compartment locked at surface areas of
underground mines, except when parked at the blast site and loading is
in progress; and
(8) Secured while parked by having--
(i) The brakes set;
(ii) The wheels chocked if movement could occur; and
(iii) The engine shut off unless powering a device being used in
the loading operation.
(b) Vehicles containing explosives shall have--
(1) No sparking material exposed in the cargo space; and
(2) Only properly secured nonsparking equipment in the cargo space
with the explosives.
(c) Vehicles used for dispensing bulk explosive material shall--
(1) Have no zinc or copper exposed in the cargo space; and
(2) Provide any enclosed screw-type conveyors with protection
against internal pressure and frictional heat.
Sec. 57.6203 Locomotives.
Explosive material shall not be transported on a locomotive. When
explosive material is hauled by trolley locomotive, covered,
electrically insulated cars shall be used.
Sec. 57.6204 Hoists.
(a) Before explosive material is transported in hoist conveyances--
(1) The hoist operator shall be notified; and
(2) Hoisting in adjacent shaft compartments, except for empty
conveyances or counterweights, shall be stopped until transportation of
the explosive material is completed.
(b) Explosive material transported in hoist conveyances shall be
placed within a container which prevents shifting of the cargo that
could cause detonation of the container by impact or by sparks. The
manufacturer's container may be used if secured to a nonconductive
pallet. When explosives are transported, they shall be secured so as
not to contact any sparking material.
(c) No explosive material shall be transported during a mantrip.
Sec. 57.6205 Conveying explosives by hand.
Closed, nonconductive containers shall be used to carry explosives
and detonators to and from blast sites. Separate containers shall be
used for explosives and detonators.
USE--SURFACE AND UNDERGROUND
Sec. 57.6300 Control of blasting operations.
(a) Only persons trained and experienced in the handling and use of
explosive material shall direct blasting operations and related
activities.
(b) Trainees and inexperienced persons shall work only in the
immediate presence of persons trained and experienced in the handling
and use of explosive material.
Sec. 57.6301 Blasthole obstruction check.
Before loading, blastholes shall be checked and, wherever possible,
cleared of obstructions.
Sec. 57.6302 Separation of explosive material.
Explosives and blasting agents shall be kept separated from
detonators until loading begins.
Sec. 57.6303 Initiation preparation.
(a) Primers shall be made up only at the time of use and as close
to the blast site as conditions allow.
(b) Primers shall be prepared with the detonator contained securely
and completely within the explosive or contained securely and
appropriately for its design in the tunnel or cap well.
(c) When using detonating cord to initiate another explosive, a
connection shall be prepared with the detonating cord threaded through,
attached securely to, or otherwise in contact with the explosive.
Sec. 57.6304 Primer protection.
(a) Tamping shall not be done directly on a primer.
(b) Rigid cartridges of explosives or blasting agents that are 4
inches (100 millimeters) in diameter or larger shall not be dropped on
the primer except where the blasthole contains sufficient depth of
water to protect the primer from impact. Slit packages of prill, water
gel, or emulsions are not considered rigid cartridges and may be drop
loaded.
Sec. 57.6305 Unused explosive material.
Unused explosive material shall be moved to a protected location as
soon as practical after loading operations are completed.
[[Page 36805]]
Sec. 57.6306 Loading, blasting, and security.
(a) When explosive materials or initiating systems are brought to
the blast site, the blast site shall be attended; barricaded and posted
with warning signs, such as ``Danger,'' ``Explosives,'' or ``Keep
Out;'' or flagged against unauthorized entry.
(b) Vehicles and equipment shall not be driven over explosive
material or initiating systems in a manner which could contact the
material or system, or create other hazards.
(c) Once loading begins, the only activities permitted within the
blast site shall be those activities directly related to the blasting
operation and the activities of surveying, stemming, sampling of
geology, and reopening of holes, provided that reasonable care is
exercised. Haulage activity is permitted near the base of bench faces
being loaded or awaiting firing, provided no other haulage access
exists.
(d) Loading and blasting shall be conducted in a manner designed to
facilitate a continuous process, with the blast fired as soon as
possible following the completion of loading. If blasting a loaded
round may be delayed for more than 72 hours, the operator shall notify
the appropriate MSHA district office.
(e) In electric blasting prior to connecting to the power source,
and in nonelectric blasting prior to attaching an initiating device,
all persons shall leave the blast area except persons in a blasting
shelter or other location that protects them from concussion (shock
wave), flying material, and gases.
(f) Before firing a blast--
(1) Ample warning shall be given to allow all persons to be
evacuated;
(2) Clear exit routes shall be provided for persons firing the
round; and
(3) All access routes to the blast area shall be guarded or
barricaded to prevent the passage of persons or vehicles.
(g) Work shall not be resumed in the blast area until a post-blast
examination addressing potential blast-related hazards has been
conducted by a person with the ability and experience to perform the
examination.
Sec. 57.6307 Drill stem loading.
Explosive material shall not be loaded into blastholes with drill
stem equipment or other devices that could be extracted while
containing explosive material. The use of loading hose, collar sleeves,
or collar pipes is permitted.
Sec. 57.6308 Initiation systems.
Initiation systems shall be used in accordance with the
manufacturer's instructions.
Sec. 57.6309 Fuel oil requirements for ANFO.
(a) Liquid hydrocarbon fuels with flash points lower than that of
No. 2 diesel oil (125 deg.F) shall not be used to prepare ammonium
nitrate-fuel oil, except that diesel fuels with flash points no lower
than 100 deg.F may be used at ambient air temperatures below 45
deg.F.
(b) Waste oil, including crankcase oil, shall not be used to
prepare ammonium nitrate-fuel oil.
Sec. 57.6310 Misfire waiting period.
When a misfire is suspected, persons shall not enter the blast
area--
(a) For 30 minutes if safety fuse and blasting caps are used; or
(b) For 15 minutes if any other type detonators are used.
Sec. 57.6311 Handling of misfires.
(a) Faces and muck piles shall be examined for misfires after each
blasting operation.
(b) Only work necessary to remove a misfire and protect the safety
of miners engaged in the removal shall be permitted in the affected
area until the misfire is disposed of in a safe manner.
(c) When a misfire cannot be disposed of safely, each approach to
the area affected by the misfire shall be posted with a warning sign at
a conspicuous location to prohibit entry, and the condition shall be
reported immediately to mine management.
(d) Misfires occurring during the shift shall be reported to mine
management not later than the end of the shift.
Sec. 57.6312 Secondary blasting.
Secondary blasts fired at the same time in the same work area shall
be initiated from one source.
ELECTRIC BLASTING--SURFACE AND UNDERGROUND
Sec. 57.6400 Compatibility of electric detonators.
All electric detonators to be fired in a round shall be from the
same manufacturer and shall have similar electrical firing
characteristics.
Sec. 57.6401 Shunting.
Except during testing--
(a) Electric detonators shall be kept shunted until connected to
the blasting line or wired into a blasting round;
(b) Wired rounds shall be kept shunted until connected to the
blasting line; and
(c) Blasting lines shall be kept shunted until immediately before
blasting.
Sec. 57.6402 Deenergized circuits near detonators.
Electrical distribution circuits within 50 feet of electric
detonators at the blast site shall be deenergized. Such circuits need
not be deenergized between 25 to 50 feet of the electric detonators if
stray current tests, conducted as frequently as necessary, indicate a
maximum stray current of less than 0.05 ampere through a 1-ohm resistor
as measured at the blast site.
Sec. 57.6403 Branch circuits.
(a) If electric blasting includes the use of branch circuits, each
branch shall be equipped with a safety switch or equivalent method to
isolate the circuits to be used.
(b) At least one safety switch or equivalent method of protection
shall be located outside the blast area and shall be in the open
position until persons are withdrawn.
Sec. 57.6404 Separation of blasting circuits from power source.
(a) Switches used to connect the power source to a blasting circuit
shall be locked in the open position except when closed to fire the
blast.
(b) Lead wires shall not be connected to the blasting switch until
the shot is ready to be fired.
Sec. 57.6405 Firing devices.
(a) Power sources shall be capable of delivering sufficient current
to energize all electric detonators to be fired with the type of
circuits used. Storage or dry cell batteries are not permitted as power
sources.
(b) Blasting machines shall be tested, repaired, and maintained in
accordance with manufacturer's instructions.
(c) Only the blaster shall have the key or other control to an
electrical firing device.
Sec. 57.6406 Duration of current flow.
If any part of a blast is connected in parallel and is to be
initiated from powerlines or lighting circuits, the time of current
flow shall be limited to a maximum of 25 milliseconds. This can be
accomplished by incorporating an arcing control device in the blasting
circuit or by interrupting the circuit with an explosive device
attached to one or both lead lines and initiated by a 25-millisecond
delay electric detonator.
Sec. 57.6407 Circuit testing.
A blasting galvanometer or other instrument designed for testing
blasting circuits shall be used to test the following:
(a) In surface operations--
(1) Continuity of each electric detonator in the blasthole prior to
stemming and connection to the blasting line;
[[Page 36806]]
(2) Resistance of individual series or the resistance of multiple
balanced series to be connected in parallel prior to their connection
to the blasting line;
(3) Continuity of blasting lines prior to the connection of
electric detonator series; and
(4) Total blasting circuit resistance prior to connection to the
power source.
(b) In underground operations--
(1) Continuity of each electric detonator series; and
(2) Continuity of blasting lines prior to the connection of
electric detonators.
NONELECTRIC BLASTING--SURFACE AND UNDERGROUND
Sec. 57.6500 Damaged initiating material.
A visual check of the completed circuit shall be made to ensure
that the components are properly aligned and connected. Safety fuse,
igniter cord, detonating cord, shock or gas tubing, and similar
material which is kinked, bent sharply, or damaged shall not be used.
Sec. 57.6501 Nonelectric initiation systems.
(a) When the nonelectric initiation system uses shock tube--
(1) Connections with other initiation devices shall be secured in a
manner which provides for uninterrupted propagation;
(2) Factory-made units shall be used as assembled and shall not be
cut except that a single splice is permitted on the lead-in trunkline
during dry conditions; and
(3) Connections between blastholes shall not be made until
immediately prior to clearing the blast site when surface delay
detonators are used.
(b) When the nonelectric initiation system uses detonating cord--
(1) The line of detonating cord extending out of a blasthole shall
be cut from the supply spool immediately after the attached explosive
is correctly positioned in the hole;
(2) In multiple row blasts, the trunkline layout shall be designed
so that the detonation can reach each blasthole from at least two
directions;
(3) Connections shall be tight and kept at right angles to the
trunkline;
(4) Detonators shall be attached securely to the side of the
detonating cord and pointed in the direction in which detonation is to
proceed;
(5) Connections between blastholes shall not be made until
immediately prior to clearing the blast site when surface delay
detonators are used; and
(6) Lead-in lines shall be manually unreeled if connected to the
trunklines at the blast site.
(c) When nonelectric initiation systems use gas tube, continuity of
the circuit shall be tested prior to blasting.
Sec. 57.6502 Safety fuse.
(a) The burning rate of each spool of safety fuse to be used shall
be measured, posted in locations which will be conspicuous to safety
fuse users, and brought to the attention of all persons involved with
the blasting operation.
(b) When firing with safety fuse ignited individually using
handheld lighters, the safety fuse shall be of lengths which provide at
least the minimum burning time for a particular size round, as
specified in the following table:
Table E-1.--Safety Fuse--Minimum Burning Time
------------------------------------------------------------------------
Number of holes in a round Minimum burning time
------------------------------------------------------------------------
1...................................... 2 min.\1\
2-5.................................... 2 min. 40 sec.
6-10................................... 3 min. 20 sec.
11 to 15............................... 5 min.
------------------------------------------------------------------------
\1\ For example, at least a 36-inch length of 40-second-per-foot safety
fuse or at least a 48-inch length of 30-second-per-foot safety fuse
would have to be used to allow sufficient time to evacuate the area.
(c) Where flyrock might damage exposed safety fuse, the blast shall
be timed so that all safety fuses are burning within the blastholes
before any blasthole detonates.
(d) Fuse shall be cut and capped in dry locations.
(e) Blasting caps shall be crimped to fuse only with implements
designed for that purpose.
(f) Safety fuse shall be ignited only after the primer and the
explosive material are securely in place.
(g) Safety fuse shall be ignited only with devices designed for
that purpose. Carbide lights, liquefied petroleum gas torches, and
cigarette lighters shall not be used to light safety fuse.
(h) At least two persons shall be present when lighting safety
fuse, and no one shall light more than 15 individual fuses. If more
than 15 holes per person are to be fired, electric initiation systems,
igniter cord and connectors, or other nonelectric initiation systems
shall be used.
EXTRANEOUS ELECTRICITY--SURFACE AND UNDERGROUND
Sec. 57.6600 Loading practices.
If extraneous electricity is suspected in an area where electric
detonators are used, loading shall be suspended until tests determine
that stray current does not exceed 0.05 amperes through a 1-ohm
resister when measured at the location of the electric detonators. If
greater levels of extraneous electricity are found, the source shall be
determined and no loading shall take place until the condition is
corrected.
Sec. 57.6601 Grounding.
Electric blasting circuits, including powerline sources when used,
shall not be grounded.
Sec. 57.6602 Static electricity dissipation during loading.
When explosive material is loaded pneumatically into a blasthole in
a manner that generates a static electricity hazard--
(a) An evaluation of the potential static electricity hazard shall
be made and any hazard shall be eliminated before loading begins;
(b) The loading hose shall be of a semiconductive type, have a
total of not more than 2 megohms of resistance over its entire length
and not less than 1000 ohms of resistance per foot;
(c) Wire-countered hoses shall not be used;
(d) Conductive parts of the loading equipment shall be bonded and
grounded and grounds shall not be made to other potential sources of
extraneous electricity; and
(e) Plastic tubes shall not be used as hole liners if the hole
contains an electric detonator.
Sec. 57.6603 Air gap.
At least a 15-foot air gap shall be provided between the blasting
circuit and the electric power source.
Sec. 57.6604 Precautions during storms.
During the approach and progress of an electrical storm--
(a) Surface blasting operations shall be suspended and persons
withdrawn from the blast area or to a safe location; or
(b) Underground electrical blasting operations that are capable of
being initiated by lightning shall be suspended and all persons
withdrawn from the blast area or to a safe location.
Sec. 57.6605 Isolation of blasting circuits.
Lead wires and blasting lines shall be isolated and insulated from
power conductors, pipelines, and railroad tracks, and shall be
protected from sources of stray or static electricity. Blasting
circuits shall be protected from any contact between firing lines and
overhead powerlines which could result from the force of a blast.
EQUIPMENT/TOOLS--SURFACE AND UNDERGROUND
Sec. 57.6700 Nonsparking tools.
Only nonsparking tools shall be used to open containers of
explosive material or to punch holes in explosive cartridges.
[[Page 36807]]
Sec. 57.6701 Tamping and loading pole requirements.
Tamping and loading poles shall be of wood or other nonconductive,
nonsparking material. Couplings for poles shall be nonsparking.
MAINTENANCE--SURFACE AND UNDERGROUND
Sec. 57.6800 Storage facilities.
When repair work which could produce a spark or flame is to be
performed on a storage facility--
(a) The explosive material shall be moved to another facility, or
moved at least 50 feet from the repair activity and monitored; and
(b) The facility shall be cleaned to prevent accidental detonation.
Sec. 57.6801 Vehicle repair.
Vehicles containing explosive material and oxidizers shall not be
taken into a repair garage or shop.
Sec. 57.6802 Bulk delivery vehicles.
No welding or cutting shall be performed on a bulk delivery vehicle
until the vehicle has been washed down and all explosive material has
been removed. Before welding or cutting on a hollow shaft, the shaft
shall be thoroughly cleaned inside and out and vented with a minimum
\1/2\-inch diameter opening to allow for sufficient ventilation.
Sec. 57.6803 Blasting lines.
Permanent blasting lines shall be properly supported. All blasting
lines shall be insulated and kept in good repair.
GENERAL REQUIREMENTS--SURFACE AND UNDERGROUND
Sec. 57.6900 Damaged or deteriorated explosive material.
Damaged or deteriorated explosive material shall be disposed of in
a safe manner in accordance with the instructions of the manufacturer.
Sec. 57.6901 Black powder.
(a) Black powder shall be used for blasting only when a desired
result cannot be obtained with another type of explosive, such as in
quarrying certain types of dimension stone.
(b) Containers of black powder shall be--
(1) Nonsparking;
(2) Kept in a totally enclosed cargo space while being transported
by a vehicle;
(3) Securely closed at all times when--
(i) Within 50 feet of any magazine or open flame;
(ii) Within any building in which a fuel-fired or exposed-element
electric heater is operating; or
(iii) In an area where electrical or incandescent-particle sparks
could result in powder ignition; and
(4) Opened only when the powder is being transferred to a blasthole
or another container and only in locations not listed in paragraph
(b)(3) of this section.
(c) Black powder shall be transferred from containers only by
pouring.
(d) Spills shall be cleaned up promptly with nonsparking equipment.
Contaminated powder shall be put into a container of water and shall be
disposed of promptly after the granules have disintegrated, or the
spill area shall be flushed promptly with water until the granules have
disintegrated completely.
(e) Misfires shall be disposed of by washing the stemming and
powder charge from the blasthole, and removing and disposing of the
initiator in accordance with the requirement for damaged explosives.
(f) Holes shall not be reloaded for at least 12 hours when the
blastholes have failed to break as planned.
Sec. 57.6902 Excessive temperatures.
(a) Where heat could cause premature detonation, explosive material
shall not be loaded into hot areas, such as kilns or sprung holes.
(b) When blasting sulfide ores where hot holes occur that may react
with explosive material in blastholes, operators shall--
(1) Measure an appropriate number of blasthole temperatures in
order to assess the specific mine conditions prior to the introduction
of explosive material;
(2) Limit the time between the completion of loading and the
initiation of the blast to no more than 12 hours; and
(3) Take other special precautions to address the specific
conditions at the mine to prevent premature detonation.
Sec. 57.6903 Burning explosive material.
If explosive material is suspected of burning at the blast site,
persons shall be evacuated from the endangered area and shall not
return for at least one hour after the burning or suspected burning has
stopped.
Sec. 57.6904 Smoking and open flames.
Smoking and use of open flames shall not be permitted within 50
feet of explosive material except when separated by permanent
noncombustible barriers. This standard does not apply to devices
designed to ignite safety fuse or to heating devices which do not
create a fire or explosion hazard.
Sec. 57.6905 Protection of explosive material.
(a) Explosive material shall be protected from temperatures in
excess of 150 degrees Fahrenheit.
(b) Explosive material shall be protected from impact, except for
tamping and dropping during loading.
GENERAL REQUIREMENTS--UNDERGROUND ONLY
Sec. 57.6960 Mixing of explosive material.
(a) The mixing of ingredients to produce explosive material shall
not be conducted underground unless prior approval of the MSHA district
manager is obtained. In granting or withholding approval, the district
manager shall consider the potential hazards created by--
(1) The location of the stored material and the storage practices
used;
(2) The transportation and use of the explosive material;
(3) The nature of the explosive material, including its
sensitivity;
(4) Any other factor deemed relevant to the safety of miners
potentially exposed to the hazards associated with the mixing of the
bulk explosive material underground.
(b) Storage facilities for the ingredients to be mixed shall
provide drainage away from the facilities for leaks and spills.
[FR Doc. 96-16861 Filed 7-11-96; 8:45 am]
BILLING CODE 4510-43-P
