OSHA limits noise to a 90 dBA average over 8 hours (the PEL) using a 5 dB exchange rate — every 5 dB louder cuts the allowed time in half. Enter a noise level and how long you are exposed to get the permissible time and your noise dose.
OSHA permissible noise exposures (1910.95)
| Sound level (dBA) | Max duration / day |
|---|---|
| 90 | 8 hours (PEL = 100% dose) |
| 95 | 4 hours |
| 100 | 2 hours |
| 105 | 1 hour |
| 110 | 30 minutes |
| 115 | 15 minutes (ceiling) |
At or above the 85 dBA action level (50% dose) you must enroll workers in a hearing conservation program. Size protection with our NRR calculator.
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FAQ
OSHA vs NIOSH limits?
OSHA uses a 90 dBA PEL with a 5 dB exchange rate. NIOSH recommends a more protective 85 dBA REL with a 3 dB exchange rate — under NIOSH, 88 dBA is only allowed for 4 hours.
What is “dose”?
The percentage of your daily allowance used. 100% dose equals an 8-hour TWA of 90 dBA. 50% dose (the action level) equals 85 dBA.
Based on OSHA 29 CFR 1910.95 (90 dBA PEL, 5 dB exchange rate). A single steady level is assumed; real shifts combine multiple levels — use a dosimeter for compliance. Not a substitute for noise monitoring.
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Built and reviewed by the WC Safety editorial team (Steven Eaton). We curate and review industrial PPE against ANSI, NIOSH and OSHA standards.