
Guidance Regulations on Reducing Noise Exposure | NIOSH ...
Sep 13, 2000 · The NIOSH REL for noise is 85 decibels, using the Aweighting frequency response (often written as dBA) over an 8hour average, usually referred to as TimeWeighted Average (TWA). Exposures at or above this level are considered hazardous. OSHA sets legal limits on noise exposure in the workplace. These limits are based on a worker's time ...