OSHA 10-Hour Construction ReviewHealth Hazards in ConstructionMedium
A construction worker is operating a jackhammer for several hours daily without hearing protection. The noise level is consistently measured at 95 dBA. According to OSHA standards, what is the maximum permissible exposure time for this noise level without hearing protection?
- A8 hours
- B1 hour
- C2 hours
- D4 hours
Show answer & explanationAnswer & explanation
Correct answer: D. 4 hours
OSHA's permissible exposure limit (PEL) for noise is 90 dBA for an 8-hour time-weighted average. The standard uses a 5 dBA exchange rate, meaning for every 5 dBA increase above 90 dBA, the permissible exposure time is halved. At 95 dBA, the permissible exposure time is 4 hours (8 hours at 90 dBA / 2).
Why the other options are wrong
- A. 8 hours is the limit for 90 dBA, not 95 dBA.
- B. 1 hour would be the limit for 105 dBA.
- C. 2 hours would be the limit for 100 dBA (90 dBA for 8 hours, 95 dBA for 4 hours, 100 dBA for 2 hours).
OSHA Noise PEL
OSHA's Permissible Exposure Limit (PEL) for noise is 90 dBA averaged over 8 hours. A 5 dBA exchange rate means exposure time is halved for every 5 dBA increase.
- PEL: 90 dBA for 8 hours.
- Action Level: 85 dBA for 8 hours (requires hearing conservation program).
- Exchange Rate: 5 dBA doubling rule.
Memory trick: Ninety for Eight, Five Decibels Halves the Fate.