OSHA 1910.95 Noise Dose and TWA
Multi-row workshift dose with the OSHA 5 dB exchange formula, 8-hr TWA.
Example
You enter
- Rows level dba 88, hours 8; level dba 95, hours 2
You get
- Total dose (%) 125.7 %
- 8-hr TWA (dBA) 91.65
Checked against published worked examples from: OSHA.
Details, formula, and sources
ScopeMulti-row workshift dose with the OSHA 5 dB exchange formula, 8-hr TWA, and pass / fail against the 85 dBA action level and 90 dBA PEL.
Formula or tableT_hr = 8 / 2^((L - 90) / 5). D_pct = sum(C_i / T_i) * 100. TWA_dBA = 16.61 * log10(D / 100) + 90. Levels below 80 dBA contribute zero to the OSHA dose.
Source and editionOSHA 29 CFR 1910.95(b) Appendix A and Table G-16a.
Free accessecfr.gov for 1910.95; cdc.gov/niosh for the NIOSH 98-126 alternative.
What governsMath aid for personal verification. Stop work and consult the qualified person on site if any number does not match the field condition.
API field namesrows, total_dose_pct, twa_dBA
- Exchange rate 5 dB (OSHA)OSHA 1910.95(b) Appendix A
- NIOSH alternative 3 dB exchange rate; not implemented here because OSHA is the regulatory recordNIOSH 98-126
- Action level TWA 85 dBA = 50% doseOSHA 1910.95(c)
- PEL TWA 90 dBA = 100% doseOSHA 1910.95(b)
- Threshold levels below 80 dBA contribute zero doseOSHA 1910.95 Appendix A