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Hearing Protection Selection Chart

A counter chart that matches measured noise exposure to the OSHA requirement and a sensible protector type, with the derating step that must be applied before comparing a label NRR to a dBA reading.

Ref SP-020129 CFR 1910.95

Draft, open for review. Check every value against the governing standard and the manufacturer’s data before use.

What it is

OSHA 29 CFR 1910.95 sets an action level of 85 dBA and a permissible exposure limit (PEL) of 90 dBA, both as 8-hour time-weighted averages (TWA). Employers must make hearing protectors available at or above the action level and must make sure the chosen protector reduces the worker's exposure to 90 dBA or below (85 dBA or below for a worker with a standard threshold shift). This chart helps the counter steer the conversation. It does not replace a noise survey or the employer's hearing conservation program.

How to use it

Get the worker's 8-hour TWA in dBA from a dosimeter or noise survey. A single sound level meter reading is not a TWA.
Find the row for that exposure.
Derate the label NRR before comparing (see the method row below).
Pick a protector that brings the estimated protected level into the target range without over-protecting.

Selection chart

8-hour TWA (dBA)	What 1910.95 requires	Typical protector approach
Below 85	No protector requirement	Offer on request for comfort; any plug or muff
85 to below 90	Protectors made available at no cost; hearing conservation program	Foam or pre-molded plugs, banded plugs, or muffs; choice and comfort matter most
90 and above	Protectors must be worn; feasible engineering or administrative controls required	Plug or muff with derated attenuation that brings exposure to 90 or below
Worker with a standard threshold shift	Protectors must be worn at 85 and above	Target 85 or below; refit and retrain
Very high exposures (NIOSH guidance: above 100 dBA TWA)	Same as 90 and above	Dual protection: plug plus muff
Derating method (Appendix B, A-weighted data)	Estimated protected level	TWA minus (NRR minus 7); OSHA field practice also halves the result

Key points

The 7 dB subtraction converts the NRR's C-weighted basis to dBA. It is not a safety factor.
Dual protection does not add the two NRRs. OSHA field practice adds 5 dB to the derated value of the higher-rated device.
Over-protection cuts off speech and warning signals and makes workers pull protectors out.
Comfort, fit and compatibility with hard hats and eyewear drive real-world use more than the label number.
Individual fit testing (ANSI S12.71) gives a personal attenuation rating that beats any derating estimate.

Common mistakes

Subtracting the full NRR from a dBA reading.
Treating a spot meter reading as an 8-hour exposure.
Selling the highest NRR to every customer by default.
Forgetting that muffs lose attenuation over safety glasses temples and long hair.

Governing standards: 29 CFR 1910.95 and Appendix B; ANSI S12.71 (fit testing); NIOSH 98-126 (guidance).

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.

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