How many hours per day can you be exposed to a noise level of 97 dB?

How many hours per day can you be exposed to a noise level of 97 dB?

• A. 3 hours
• B. 2 hours
• C. 4 hours
• D. 1 hour

Answer: (A)

The main idea is how OSHA limits noise exposure using a 5 dB exchange rate. Under the PEL, unprotected exposure at 90 dBA is allowed for 8 hours. For every 5 dB increase, the allowable time is cut in half. So 95 dBA allows 4 hours, and 100 dBA allows 2 hours. A level of 97 dB sits between 95 and 100 dB, and with the standard calculation, the allowable exposure is about 3 hours per day. In formula terms, T = 8 × 2^[(90 − L)/5]; with L = 97, T ≈ 3 hours. Note that wearing hearing protection can extend exposure time, but the 3 hours reflects unprotected exposure.

The main idea is how OSHA limits noise exposure using a 5 dB exchange rate. Under the PEL, unprotected exposure at 90 dBA is allowed for 8 hours. For every 5 dB increase, the allowable time is cut in half. So 95 dBA allows 4 hours, and 100 dBA allows 2 hours. A level of 97 dB sits between 95 and 100 dB, and with the standard calculation, the allowable exposure is about 3 hours per day. In formula terms, T = 8 × 2^[(90 − L)/5]; with L = 97, T ≈ 3 hours. Note that wearing hearing protection can extend exposure time, but the 3 hours reflects unprotected exposure.