What is the OSHA permissible exposure limit (PEL) for workplace noise, and how is it applied?

• A. 90 dBA for an 8-hour TWA; exposures near or beyond require controls and hearing conservation.
• B. 85 dBA for 10 hours; depends on company policy.
• C. 95 dBA for 8-hour TWA; no special controls required.
• D. 100 dBA for 8-hour TWA; only personal protective equipment required.

Answer: (D)

The main concept is how OSHA sets and applies noise exposure limits. OSHA’s permissible exposure limit for workplace noise is 90 dBA as an 8-hour time-weighted average. If workers are exposed at or near that level, exposure must be controlled to keep the TWA at or below 90 dBA. An action level exists at 85 dBA, which triggers a hearing conservation program that includes monitoring, engineering and administrative controls, hearing protection, training, and periodic audiometric testing. The 5 dB exchange rate means the allowable exposure time halves with every 5 dB increase in noise; for example, at 95 dBA the limit is 4 hours, at 100 dBA it's 2 hours, and so on. So a scenario claiming 100 dBA for 8 hours would not meet OSHA requirements unless steps are taken to reduce exposure below the PEL. PPE alone typically does not satisfy the standard; effective protection combines controls and protective equipment.