What are the NIOSH recommendations for exchange rates associated with time weighted averages (TWAs)?

The NIOSH (National Institute for Occupational Safety and Health) recommendations for exchange rates associated with time-weighted averages (TWAs) suggest that an increase in sound level by 3 dB constitutes a doubling of the noise exposure. This means that for every increase of 3 dB, the permissible exposure time is cut in half, assuming an equal energy exchange applicable to continuous noise.

For example, if a worker is exposed to a noise level of 90 dB, according to the 3 dB exchange rate, the allowable exposure time becomes significantly more restricted as the noise level increases. This framework is essential for protecting workers from hearing loss, as it emphasizes the relationship between sound intensity and exposure duration. Understanding this exchange rate assists occupational health professionals in assessing risks and implementing effective hearing conservation programs.