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Safety Standards for Explosives at Metal and Nonmetal Mines

 

SECTION 57

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.

 

 

 

 

 

 

 

 

 

 

 

 

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.   

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  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 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 

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)  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.   

    (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  indicates 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;   

    (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.   

    (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. 

 

    (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   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 

 

  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  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 

    (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. 

 

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;   

    (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 non-electric 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 blast hole 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 power lines  which could result from the force of a blast. 

 

EQUIPMENT/TOOLS--SURFACE AND UNDERGROUND 

 

Sec. 57.6700  Non-sparking tools. 

 

    Only non-sparking tools shall be used to open containers of explosive material or to punch holes in explosive cartridges. 

 

 

 

Sec. 57.6701  Tamping and loading pole requirements. 

 

    Tamping and loading poles shall be of wood or other nonconductive, non-sparking material.  Couplings for poles shall be non-sparking. 

 

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) Non-sparking; 

    (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 blast hole 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 non-sparking 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 blast hole, 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 blast holes 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.