MSHA Issues Direct Rule to Include Electronic Detonators in Regulations

By: Nicholas W. Scala and Daniel Deacon

On January 14, 2020, the Mine Safety and Health Administration published a Direct Final Rule revising certain safety standards regarding explosive materials at Metal and Nonmetal (M/NM) mines – specifically relating to the use of electronic detonators.  The direct rule will become effective on March 16, 2020, “unless substantive adverse comments* are received or postmarked by midnight Eastern Standard Time on February 13, 2020.  If adverse comment is received, MSHA will publish a timely withdrawal of the rule in the Federal Register.”

A concurrent Proposed Rule was published in the Federal Register to speed up notice and comment rulemaking should the agency decide to withdraw the direct rule. However, all interested parties who wish to comment should comment at this time “because MSHA does not anticipate initiating an additional comment period.

Background of Rule

As part of Assistant Secretary Zatezalo’s continued push to embrace technological advancements in the mining industry, MSHA seeks to update an aging regulation to include reference to modern systems. MSHA for the most part has utilized the same definition for detonators since 1979 – with the exception of a minor modification in 1991.Detonators direct rule The standards have defined “detonators to mean any device containing a detonating charge that is used to initiate an explosive such as electric blasting caps and non-electrical instantaneous or delay blasting caps.” MSHA anticipated that the existing definition would continue to cover new developments in detonator technology but has not found that to be the case given advancements in computer and micro-processing technologies – which have led to the development of “electronic” detonators.

Historically, MSHA’s standards have included only two types of detonators in the definition: non-electric (includes devices such as detonating cords, shock-tube or safety fuse detonators, or a combination of these), or electric (uses electrical currents to initiate detonation).

The addition of electronic detonators (designed to use electronic components to transmit a firing signal with validated commands and secure communications to each detonator, and a detonator cannot be initiated by other means) will serve to update the regulations to include what is at this point the is the technology in use by the majority of operations.

On September 28, 2004, MSHA issued Program Information Bulletin (PIB) No. P04-20, Electronic Detonators and Requirements for Shunting and Circuit Testing. The PIB discussed how to rectify MSHA requirements on shunting and circuit testing with the advanced electronic detonators. During its review of electronic detonators, MSHA found that the systems contained internal safeguards for shunting and circuit testing and that these systems satisfy MSHA regulation as long as the manufacturer instructions are followed.

Proposed Revisions

In 2018, MSHA requested comments from industry stakeholders on which existing regulation(s) should be repealed, replaced, or modified without reducing miners’ safety and health. The changes proposed in this direct rule were largely the result of comments from the Institute of Makers of Explosives (IME), which requested that MSHA update its regulations to recognize the significant developments in safety and sophistication offered by electronic detonators.

In the rule MSHA addresses the use of electronic detonators in M/NM surface and underground mines and modifies §§ 56/57.6000, the definition of “Detonator;” 56/57.6310, Misfire waiting period; 56/57.6407, Circuit testing; and 57.6604, Precautions during storms. MSHA is amending certain portions of the explosives standards to include electronic detonators. However, the other explosives standards in subparts E in 30 CFR parts 56 and 57 continue to apply to electronic detonators.

The key modifications to MSHA’s regulations are as follows:

  • §56/57.6000: adding the term “electronic detonator” to the definition for detonator;
  • §56/57.6310: adding a new paragraph which requires a 30-minute waiting period, or for the manufacturer-recommended time, whichever is longer, in the event of a misfire while blasting with an electronic detonator;
  • §56/57.6407: adding requirement that electronic detonators must be circuit tested to prevent misfire; and
  • 57.6604: clarifying that – in addition to underground electrical blasting – underground electronic blasting must also be suspended and all persons withdrawn from the blast area or to a safe location.

MSHA intends that the rule will serve to remove questions regarding applicability of existing to regulations to electronic detonators, thereby “mine operators will be able to use resources more efficiently when making business decisions.”

 “Through these clarifications, MSHA will ensure the safety advantages offered by electronic detonators are available to mine operators, including greater operator control to limit use to authorized personnel, more precise timing, reduced vibrations, and a reduced sensitivity to stray electrical currents and radio frequencies. Furthermore, consistent with the directive in [President Trump’s Executive Order] E.O. 13777, this direct final rule will update outdated regulations and accommodate technological advances.”

If any comments are to be submitted on these direct final rule, now is the time, as MSHA does not intend to grant an additional comment period and the rule will remain final unless the agency is persuaded that the rule is inappropriate, ineffective, less safe than other alternatives, or unacceptable without a change.  Again, comments are due by February 13, 2020. Any questions or inquiries regarding comments on the Direct Final Rule can be directed to Conn Maciel Carey’s MSHA Practice Group.


*For purposes of this direct final rule, a significant adverse comment is one that explains why the rule would be inappropriate, including challenges to the rule’s underlying premise or approach, or why it would be ineffective, less safe than other alternatives, or unacceptable without a change. In determining whether a significant adverse comment merits withdrawal of this direct final rule, MSHA will consider whether the comment raises an issue significant enough to warrant a substantive response in a notice-and-comment process. A comment recommending an addition to the rule should explain why this rule would be ineffective, less safe than other alternatives, or unacceptable without the addition.

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