In general industry the action level is an 8-hour time-weighted average of 85 dBA. Cross it and you owe a full hearing conservation programme: monitoring, audiometric testing, hearing protector choice, training, and recordkeeping. The…
In general industry the action level is an 8-hour time-weighted average of 85 dBA. Cross it and you owe a full hearing conservation programme: monitoring, audiometric testing, hearing protector choice, training, and recordkeeping. The permissible exposure limit is 90 dBA, and the gap between the two catches employers out - a plant averaging 87 dBA is under the PEL and still owes the entire programme.
Dosimetry over a representative shift tells you which job classifications are above the action level. Without it you are either testing people who do not need it or, more commonly, missing people who do. Monitoring has to be repeated when a process, equipment or control changes enough to alter exposures - a new line or a removed enclosure is a trigger.
An average shift of 10 dB or more at 2000, 3000 and 4000 Hz against baseline is a standard threshold shift. Once confirmed, you have 21 days to notify the employee in writing, and you must refit and retrain them in hearing protection. A retest within 30 days is permitted before confirming - and it resolves a fair number, because temporary shifts from a noisy shift or a head cold are common.
A confirmed standard threshold shift that also leaves the employee at an average of 25 dB or more above audiometric zero in the same ear is recordable on the OSHA 300 log. Both conditions, not either. This is the single most misapplied rule in the standard - we compute it for you and show the arithmetic rather than just asserting the answer.
Annual training must cover the effects of noise, the purpose and care of protectors, and the purpose of audiometric testing. In practice the part that changes behaviour is fitting: most people wearing foam plugs are wearing them wrong, and five minutes of hands-on correction does more than an hour of presentation.
Primary regulations and standards referenced above. Where a standard is published commercially it is named in full rather than linked to a copy.