In 1999, MSHA published new health standards for Occupational Noise Exposure. The revised noise rule took effect on September 13, 2000 in the form of 30 CFR Part 62. Prior legislation had not been updated for 20 years. The following key requirements were established within the noise rule.
- Requires mine operators to use all feasible engineering and administrative controls to reduce miners noise exposure to the "permissible exposure level (PEL). Hearing protectors are not permitted in lieu of such controls. The PEL is defined as 90 dBA measured as an 8-hour time-weighted average (TWA8). Establishes an action level at 50% of the PEL, at which miners must be enrolled in a hearing conservation program (HCP). The action level is defined as 85 dBA measured as TWA8.
- The HCP includes provisions for assessing miners noise exposure; audiometric (hearing) tests; hearing protectors; training; and recordkeeping.
- Mine operators must also ensure that no miner is exposed at any time to sound levels exceeding 115 dBA.
The following table, adopted from the MSHA Noise Regulation Fact Sheet, details the requirements of the mine operator with respect to measured exposure levels defining a miner's noise exposure.
|If a miner's noise exposure is...||Then a mine operator is required to...|
|Below the action level||No requirements|
|Equals or exceeds the action level but does not exceed the PEL||Enroll the miner in a hearing conservation program (HCP).
Provide hearing protectors to the miner.
Ensure that the hearing protectors are worn if the miner has a standard threshold shift or it will be longer than 6 months before receiving a baseline audiogram.
|Exceeds the PEL||Use all feasible engineering and administrative controls to reduce miners noise exposure to the PEL.
Enroll the miner in an HCP.
Provide hearing protectors and ensure they are worn, if unable to reduce exposure to the PEL.
|Exceeds 105 dBA TWA8 (dual hearing protection level)||Same as exceeds the PEL, plus provide the miner with both ear plug and ear muff type hearing protectors and ensure they are worn concurrently.|
|Instantaneous measurements of noise exceed 115 dBA||No miners, including those with dual hearing protectors, are permitted to be exposed to sound levels exceeding 115 dBA.|
Additional information on noise standards may be found at the Mine Safety and Health Administration website.