OSHA 10-Hour Construction ReviewHealth Hazards in ConstructionHard
A construction worker is exposed to a continuous noise level of 95 dBA over an 8-hour workday. According to OSHA standards, what is the maximum permissible duration for this exposure without hearing protection?
- A4 hours
- B1 hour
- C2 hours
- D8 hours
Show answer & explanationAnswer & explanation
Correct answer: A. 4 hours
OSHA's Permissible Exposure Limit (PEL) for noise is 90 dBA for an 8-hour Time Weighted Average (TWA). For every 5 dBA increase above 90 dBA, the permissible exposure time is halved. Therefore, for 95 dBA, the permissible exposure is 4 hours (8 hours / 2).
Why the other options are wrong
- B. 1 hour is the permissible exposure for 105 dBA.
- C. 2 hours is the permissible exposure for 100 dBA.
- D. 8 hours is the PEL for 90 dBA, not 95 dBA.
OSHA Noise PEL Exchange Rate
OSHA uses a 5 dBA exchange rate for noise exposure; for every 5 dBA increase in noise level above 90 dBA, the permissible exposure time is halved.
- PEL for 8 hours is 90 dBA.
- 5 dBA exchange rate.
- Example: 95 dBA = 4 hours, 100 dBA = 2 hours.
Memory trick: 5 dBA up, time cuts in half!