OSHA 10-Hour Construction ReviewPersonal Protective Equipment (PPE)Hard
A construction worker is using a jackhammer for an extended period. The noise level at the operator's ear is measured at 100 dBA. According to OSHA, what is the maximum permissible exposure time for this worker without hearing protection?
- A4 hours
- B1 hour
- C8 hours
- D2 hours
Show answer & explanationAnswer & explanation
Correct answer: D. 2 hours
OSHA's permissible exposure limit (PEL) for noise is 90 dBA for an 8-hour time-weighted average. For every 5 dBA increase above 90 dBA, the permissible exposure time is halved. At 100 dBA, this means 2 hours (90 dBA = 8h, 95 dBA = 4h, 100 dBA = 2h).
Why the other options are wrong
- A. 4 hours is permissible at 95 dBA, not 100 dBA.
- B. 1 hour is permissible at 105 dBA, not 100 dBA.
- C. 8 hours is permissible at 90 dBA, not 100 dBA.
OSHA Permissible Noise Exposure
OSHA sets permissible noise exposure limits based on dBA levels and exposure duration, using a 5 dBA exchange rate.
- PEL: 90 dBA for an 8-hour Time-Weighted Average (TWA).
- 5 dBA Exchange Rate: For every 5 dBA increase, permissible exposure time is halved.
- Action Level: 85 dBA TWA, triggering a hearing conservation program.
Memory trick: Every Five Decibels, Time Halves for the Rebels!