5/7/25
In the matter of PETITION FOR MODIFICATION
Signal Peak Energy LLC
Bull Mountains Mine No 1
Mine I.D. No. 24-01950
Docket Number Regulation Petitioned
Docket No. M-2025-012-C 30 C.F.R. § 75.507-1(a)
PROPOSED DECISION AND ORDER
On December 4, 2024, Signal Peak Energy, LLC filed the above listed petition for modification seeking a modification of the application of the above-referenced standard to its Bull Mountains Mine No 1 located at 100 Portal Drive, Roundup, MT 59072, in Musselshell County, Mine ID. No. 24-01950, to permit the use of Powered Air Purifying Respirators (PAPRs) inby the last open crosscut that MSHA has not approved as permissible under 30 C.F.R. Part 18. Specifically, the Petitioner is requesting to utilize the Drager X-Plore 8700 EX PAPR. The Petitioner alleges that the alternative method outlined in the petition will, at all times, guarantee no less than the same measure of protection afforded by the standard.
Title 30 C.F.R. § 75.507-1(a) Permissible electric equipment states:
All electric equipment, other than power-connection points, used in return air outby the last open crosscut in any coal mine shall be permissible except as provided in paragraphs (b) and (c) of this section.
The Petitioner states that:
1. It currently utilizes 3M VersafloTM TR-800 PAPRs, that were approved for use under a previous petition. The company’s request to utilize Dräger units, seeks to leverage its improved performance, battery life, durability, and air volume capacity to provide employees with the best protection available. The petitioner asserts the proposed modification will provide no less than the same level of protection to affected miners and proposes to establish an alternative, as detailed herein.
2. MSHA-approved permissible PAPRs are widely discontinued, and although not MSHA approved, the proposed Dräger X-plore 8700 PAPR is certified as intrinsically safe to use in explosive or dusty environments. It is approved with an intrinsically safe (IS) rating of Class I, Zone 1, AEx ib IIB T4 Gb for explosive gas environments, and Zone 21, AEx ib IIIB 135°C Db for combustible dust environments, under standards including CAN/CSA-C22.2 No. 60079-11:14 and ANSI/UL 60079-11:13. These certifications ensure the unit’s safe operation in hazardous locations where explosive gases or dusts may be present.
MSHA personnel investigated the merits of the petition with respect to the technical sufficiency of the proposed equipment. After a careful review of the merits of the petition, the Administrator issues this Proposed Decision and Order.
FINDINGS OF FACT AND CONCLUSIONS OF LAW
The term “Intrinsic Safety” is a safety methodology used in hazardous environments, such as underground mines, where gases like methane could ignite and cause an explosion. “Intrinsic Safety” means designing electrical equipment so it will not cause a spark or get hot enough to start a fire or ignite an explosion, even if something goes wrong with the subject device. “One-fault Intrinsic Safety” means an electrical device will not spark or overheat even if one component of the device fails. “Two-fault Intrinsic Safety” means an electrical device will not spark or overheat even if two independent components of the device fail at the same time, thereby offering a greater level of protection and safety.
MSHA’s existing approval standards, under 30 C.F.R. Part 18, require two-fault intrinsic safety for electrical and electronic equipment. As such, MSHA evaluates this equipment to ensure that it provides two-fault Intrinsic Safety as part of its certification process for permissibility. The criteria MSHA uses to evaluate equipment for Intrinsic Safety are published in a document referred to as ACRI2001 (MSHA, 2017).
NIOSH researchers, in a paper titled “An Evaluation of the Relative Safety of U.S. Mining Explosion-Protected Equipment Approval Requirements versus those of International Standards” (NIOSH, 2017), have determined that equipment that meets two-fault Intrinsic Safety as defined in the ANSI/UL 60079-11:13 standard “ia” would provide at least an equivalent level of safety as that provided by equipment approved by the MSHA criteria found in ACRI2001.
MSHA Enforcement submitted information regarding the UL listing for the Drager X-Plore 8700 EX PAPRs to the Agency’s technical experts at its Approval and Certification Center (A&CC). A&CC conducted a review and determined the following.
The Drager X-Plore 8700 EX model has received certification from CSA Group, which is a Nationally Recognized Test Laboratory, under ANSI/UL 60079-0:2020 and ANSI/UL 60079-11:13.
The CSA Group certification issued to Drager allows the Drager X-Plore 8700 EX to be marked as “Ex ib IIB T4 Gb” and “Ex ib IIIB T135°C Db”. These markings indicate the following:
1. The unit is certified to be used in hazardous locations, “Ex”
2. The unit has met the second-most onerous level of Intrinsic Safety protection, “ib”
3. The level of protection is acceptable for use in non-mining locations (“IIB” for gases and “IIIB” for dusts), and
4. The unit is not certified for use in mining applications.
In other words, the Drager X-Plore 8700 EX is certified as “ib” which means it only provides one-fault Intrinsic Safety. It is not certified as “ia” which means it does not provide two-fault Intrinsic Safety. Because one-fault Intrinsic Safety provides less protection from ignition and explosion hazards than MSHA’s standards that require two-fault Intrinsic Safety for electrical and electronic equipment, MSHA cannot approve this petition.
The Drager X-Plore 8700 EX PAPR cannot be used as safely in areas where permissibility is required. The level of protection for which this PAPR is certified, ANSI/UL 60079-0:2020 and ANSI/UL 60079-11:13, does not provide the same level of protection as MSHA’s requirement or the standards noted by NIOSH. MSHA’s requirements include the use of two faults of Intrinsic Safety be applied to the circuitry, which the Drager Xplore 8700 EX does not meet.
MSHA notes that Petitioner does still have viable, alternative PAPR options, namely the use of the Versaflo TR-800 Intrinsically Safe PAPR, which was previously granted to the subject operator and mine.
ORDER
Wherefore, pursuant to the authority delegated by the Secretary of Labor to the Administrator for Mine Safety and Health Enforcement and pursuant to Section 101(c) of the Federal Mine Safety and Health Act of 1977, 30 U.S.C. § 811(c), it is ordered that Signal Peak Energy LLC’s Petition for Modification of the application of 30 C.F.R. § 75.507-1(a) in the Bull Mountains Mine No 1 is hereby:
DENIED
Any party to this action desiring a hearing on this matter must file in accordance with 30 C.F.R. § 44.14 within 30 days. The request for hearing must be filed with the Administrator for Mine Safety and Health Enforcement, 200 Constitution Avenue NW, Washington, DC 20210.
If a hearing is requested, the request shall contain a concise summary of position on the issues of fact or law desired to be raised by the party requesting the hearing, including specific objections to the proposed decision. A party other than the Petitioner who has requested a hearing may also comment upon all issues of fact or law presented in the petition and any party to this action requesting a hearing may indicate a desired hearing site. If no request for a hearing is filed within 30 days after service thereof, the Decision and Order will become final and must be posted by the operator on the bulletin board at the mine.
Timothy R. Watkins
Acting Administrator for
Mine Safety and Health Enforcement
Certificate of Service
I hereby certify that a copy of this proposed decision was served personally or mailed, postage paid, or provided by other electronic means this 7th day of May, 2025, to:
Curtis Focht, PE
Signal Peak Energy, LLC,
100 Portal Dr
Roundup, MT 59072
(406)323-4582
cfocht@signalpeakenergy.com
Avichai Bass
General Engineer