OSHA’s letter of interpretation (LOI) dated July 30, 2025 answers a question regarding OSHA’s noise standard (29 CFR § 1910.95). Specifically, this letter interprets enforcement of the impact noise level under 1910.95(b)(2). The standard states in a footnote to table G-16 of permissible exposure limits (PELs) that exposures to impulsive or impact noise should not exceed 140 dB peak sound pressure level, indicating an advisory guideline. It does not say must or shall, which indicates a mandatory requirement.
OSHA’s response acknowledges that the impact level is not a PEL or action level, implying they can’t issue citations for exceeding it. However, the letter states it has been OSHA’s longstanding position that exposure above 140 dB can cause irreversible hearing damage within a short period of time and cites National Institute for Occupational Safety and Health (NIOSH) and other publications to support this position.
Colden searched for OSHA citations for exceeding the peak level under the general duty clause (GDC) and did not find any. We suspect this is because one of the criteria limiting OSHA’s ability to use the GDC for enforcement is the absence of an applicable hazard-specific standard. Because the noise standard exists and uses the term “should” for the impact limit, OSHA would have difficulty making a GDC citation stick under legal challenge.
Regardless of compliance and enforcement considerations, Colden recommends controlling impact noise exposures due to the hearing damage risks. Furthermore, noise from impacts can contribute significantly to time-weighted average exposures. This could result in exceeding OSHA’s PEL or action level and OSHA enforcement. If elimination or engineering controls are not feasible, hearing protection should be worn.
Monitoring for impact noise is challenging. Peak sound pressure levels often exceed the upper range of standard sound level meters and dosimeters. Properly integrating very short-duration impacts, such as those produce by shooting firearms, requires specialized noise monitoring equipment with higher upper ranges and very fast sampling rates. A typical type 2 sound level meter set on fast or even impulse response will likely not capture all of the energy. Specialized equipment exists for monitoring impulse noise, and Colden consultants can customize monitoring programs to characterize this special type of noise.
To learn more about Colden’s service offerings regarding all aspects of noise monitoring and hearing conservation, connect with a consultant by submitting an inquiry.
