These are the two most commonly confused values in hearing conservation. The action level — 85 dBA as an 8-hour TWA — triggers the requirement to implement a full hearing conservation program: monitoring, audiometric testing, HPD provision, training, and recordkeeping (29 CFR 1910.95(c)(1)).
These are the two most commonly confused values in hearing conservation. The action level — 85 dBA as an 8-hour TWA — triggers the requirement to implement a full hearing conservation program: monitoring, audiometric testing, HPD provision, training, and recordkeeping (29 CFR 1910.95(c)(1)). The permissible exposure limit (PEL) — 90 dBA as an 8-hour TWA — is the threshold at which feasible engineering and administrative controls must be implemented to reduce exposure (29 CFR 1910.95, Table G-16). Three distinctions matter in practice: (1) the action level triggers the Hearing Conservation Program; the PEL triggers noise control obligations; (2) exceeding the PEL does not exempt the employer from Hearing Conservation Program requirements — both apply; (3) NIOSH recommends a more protective 85 dBA REL using a 3 dB exchange rate, compared to OSHA’s 5 dB exchange rate. Content that cites NIOSH guidance must clarify that NIOSH recommends rather than requires.
