MSHA Noise Standard for Mining: How 30 CFR Part 62 Differs from OSHA 1910.95

Mine operators — coal, metal, nonmetal, and surface mining — are not regulated by OSHA’s 1910.95. They are regulated by the Mine Safety and Health Administration’s noise standard, 30 CFR Part 62. The two standards share the same 90 dBA permissible exposure limit and the same 85 dBA action level, but differ meaningfully in audiometric testing frequency, dual hearing protection requirements, administrative control requirements, and the penalty structure for violations. Understanding the differences between MSHA 30 CFR Part 62 and OSHA 29 CFR 1910.95 is essential for any operator in coal, hard rock, aggregate, or quarry operations.

Soundtrace provides hearing conservation program services to mining and aggregate operations subject to MSHA Part 62, including audiometric testing, noise monitoring, and Professional Supervisor oversight.

Who Is Covered by MSHA 30 CFR Part 62?

Part 62 applies to all mine operators — coal, metal, and nonmetal — and covers both surface and underground operations. This includes hard rock mines, coal mines, quarries, aggregate operations, and sand and gravel operations. It does not apply to oil and gas extraction operations, which are covered by OSHA.

MSHA has exclusive federal jurisdiction over mining operations under the Federal Mine Safety and Health Act of 1977. Operators subject to MSHA jurisdiction are not simultaneously subject to OSHA jurisdiction for the same operation. A company with both a manufacturing plant and a quarry on adjacent properties has the plant under OSHA 1910.95 and the quarry under MSHA Part 62.

The Dual Hearing Protection Requirement: MSHA’s Most Important Distinction

Under 30 CFR 62.170(b), miners whose noise exposure equals or exceeds 105 dBA TWA must wear dual hearing protection — simultaneous use of both earplugs and earmuffs. This requirement has no direct equivalent in OSHA 1910.95, which requires only that hearing protection attenuate exposure to below the PEL without specifying dual protection at any specific level.

The practical significance is substantial for underground mining, quarry blasting operations, and heavy equipment operators. Operators at these exposure levels must ensure both that dual protection is provided and that workers are trained and required to use both devices simultaneously. A single-device HPD program at a site with 110 dBA exposures is non-compliant with MSHA Part 62.

Audiometric Testing Under MSHA Part 62

MSHA Part 62 requires audiometric testing at the same baseline and annual frequency as OSHA 1910.95, with one important addition: miners who have received notification of a confirmed MSHA STS are placed on an enhanced surveillance schedule requiring audiometric testing at 6-month intervals until MSHA is satisfied with the program’s response. OSHA has no equivalent enhanced surveillance requirement.

Audiometric testing under MSHA must be conducted by an audiologist or physician, or by a technician under the supervision of an audiologist or physician. MSHA recognizes CAOHC certification for technicians as meeting the competence requirement, similar to OSHA.

MSHA STS Definition and Response Requirements

MSHA’s STS definition in Part 62 mirrors OSHA’s: an average shift of 10 dB or more at 2000, 3000, and 4000 Hz compared to the baseline audiogram. MSHA also uses a 2 dB age correction table that differs slightly from OSHA’s Appendix F tables. When an MSHA STS is confirmed, the operator must: notify the miner in writing within 10 working days (tighter than OSHA’s 21 calendar days); provide the miner with a copy of their audiogram results; review and update the HCP; and transfer the miner to a lower-noise area if feasible and if the miner consents.

Frequently asked questions