Combines noise exposure across multiple periods of a shift into a single daily figure, checked against the standard action and limit values. Two tabs for the two exchange-rate conventions in common use.
Read before use: This estimates exposure from sound levels and durations you enter — it is not a substitute for an actual noise survey by a competent person using calibrated equipment. Real workplace noise varies with task, equipment condition, and position; use measured data where available, and always err toward hearing protection when in doubt.
Enter every distinct period of the shift at a different noise level, in dB(A). Periods don't need to add up to 8 hours — the formula automatically normalizes to the 8-hour reference day.
DAILY EXPOSURE (LEP,d)
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Total time entered—
Lower action value80 dB(A)
Upper action value85 dB(A)
Exposure limit value87 dB(A)
Enter every distinct period of the shift at a different noise level, in dB(A). Uses the 5dB exchange rate and the standard 90dBA/8hr permissible exposure reference (OSHA 1910.95, Table G-16).
DAILY NOISE DOSE
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Total time entered—
Action level85 dBA (50% dose)
Permissible exposure limit90 dBA (100% dose)
Quick reference
EU / UK action & limit values
80 dB(A) — Lower Exposure Action Value: information, training, and hearing protection made available on request
87 dB(A) — Exposure Limit Value (accounting for any hearing protection worn): must never be exceeded
US OSHA action level & PEL
85 dBA (50% dose) — Action Level: triggers the Hearing Conservation Program (audiometric testing, training, hearing protection)
90 dBA (100% dose) — Permissible Exposure Limit: the enforceable 8-hour limit under 29 CFR 1910.95
Why the two systems differ
EU/UK uses a 3dB exchange rate (equal energy principle) — exposure time must halve for every 3dB increase to keep the same dose
US OSHA uses a 5dB exchange rate — exposure time halves for every 5dB increase instead, which permits longer exposure at high levels than the 3dB approach
Use whichever system applies to your jurisdiction and company policy — some operators apply the stricter 3dB approach everywhere regardless of location
Good practice
Measured noise data from a calibrated sound level meter or dosimeter is always better than an estimate
Impulsive/impact noise (e.g. hammering, explosive tools) needs separate peak-level assessment — this tool doesn't cover peak/impulse limits
Hearing protection reduces exposure, but its real-world attenuation is usually well below the lab-tested rating — don't assume the full marked reduction