JavaScript is off. Reference tables, cheat sheets and guides below are fully readable. The calculators, search and navigation need JavaScript — everything still runs in your browser, nothing is sent anywhere. Browse all tools

Noise Exposure Dose

Two regimes that disagree. OSHA uses a 5 dB exchange rate from 90 dBA; NIOSH and the EU use 3 dB from 85 dBA. The 3 dB rule is the physically honest one — equal energy — and it is far stricter: at 95 dBA OSHA allows four hours, NIOSH allows under one.

Standard

Task A level (dBA)

Task A hours

Task B level (dBA)

Task B hours

Task C level (dBA, 0 = none)

Daily dose

—

Equivalent 8-h TWA

—

Within the limit?

—

Allowed time — task A

—

Allowed time — task B

—

Under the other standard

—

Dose is cumulative across the day — several short loud tasks add up fast. Hearing protection is rated separately by its own attenuation (NRR/SNR), which this does not apply. Always state which exchange rate you used.

A helper, not a substitute for engineering judgment. Verify against the governing standard.