The OSHA limit for an 8-hour time-weighted average noise exposure is below how many decibels?

The OSHA limit for an 8-hour time-weighted average noise exposure is below how many decibels?

• A. 90 dB
• B. 80 dB
• C. 85 dB
• D. 95 dB

Answer: (C)

Time-weighted average noise exposure is limited by OSHA to protect workers over an 8-hour shift. The permissible exposure limit is 90 dBA for 8 hours. This uses a 5 dB exchange rate, meaning for every 5 dB increase above the limit, the allowable exposure time halves. So at 90 dB you’re limited to about 8 hours; at 95 dB it drops to about 4 hours; at 100 dB around 2 hours, and so on. That makes the maximum level you should be below for an 8-hour shift 90 dBA. The figure of 85 dBA is tied to other standards (like some guidelines that use a different exchange rate), but OSHA’s PEL for an 8-hour TWA is 90 dBA.

Time-weighted average noise exposure is limited by OSHA to protect workers over an 8-hour shift. The permissible exposure limit is 90 dBA for 8 hours. This uses a 5 dB exchange rate, meaning for every 5 dB increase above the limit, the allowable exposure time halves. So at 90 dB you’re limited to about 8 hours; at 95 dB it drops to about 4 hours; at 100 dB around 2 hours, and so on. That makes the maximum level you should be below for an 8-hour shift 90 dBA. The figure of 85 dBA is tied to other standards (like some guidelines that use a different exchange rate), but OSHA’s PEL for an 8-hour TWA is 90 dBA.