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Safety Standards for Explosives at Metal and Nonmetal Mines; Final Rule [07/12/96]

Volume 61, Number 135, Page 36789-36807

[[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  
  
[[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.  
  
-----------------------------------------------------------------------  
  
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.  
  
4Sec. 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--  
  
    (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.