Occupational exposure · framework-specific screening
Occupational Noise Exposure Screening Worksheet
Calculate documented workshift contributions under one selected framework. EU daily exposure level and OSHA dose/TWA are different quantities and are never blended.
Exposure record
All fields start blank. Use one row for each non-overlapping period with a distinct representative level.
Framework-specific result
EU branch — daily action-value screen
Enter a representative equivalent continuous A-weighted sound pressure level, LAeq,Tᵢ, and duration Tᵢ for every work period, before hearing-protector attenuation. The worksheet combines acoustic energies and normalizes them to eight hours:
For one period this reduces to LEX,8h = LAeq,T + 10 log₁₀(T/8 h). This is an energy-normalization calculation, not a 3 dB “permissible-time” law and not an EU noise dose.
| Directive 2003/10/EC quantity | Valore | What this worksheet does |
|---|---|---|
| Lower exposure action value | 80 dB(A), LEX,8h | Numerical comparison using unprotected exposure |
| Upper exposure action value | 85 dB(A), LEX,8h | Numerical comparison using unprotected exposure |
| Exposure limit value | 87 dB(A), effective exposure | Not evaluated: individual protector attenuation is required |
| Peak values | 112/140/200 Pa = 135/137/140 dB(C) | Not evaluated: LCpeak is a separate input quantity |
The Directive is a minimum-requirements instrument. Check the applicable national implementation and any stricter or sector-specific provisions.
OSHA branch — general-industry Appendix A
Enter segment LAVG values in dBA using OSHA’s 5 dB exchange relationship and the applicable Slow-response settings. Appendix A defines the reference duration and workshift dose:
D = 100 Σ(Cᵢ/Tᵢ)
TWA = 16.61 log₁₀(D/100) + 90
The page calculates two integrations because the thresholds differ:
- Hearing-conservation screen: include 80–130 dBA; 50% dose corresponds to 85 dBA TWA.
- PEL/control screen: include 90–130 dBA; 100% dose corresponds to 90 dBA TWA.
- Above 115 dBA: Appendix A may still supply a TWA calculation aid, but OSHA states that this does not imply acceptability; Table G-16 limits continuous/intermittent exposure to no more than 115 dBA for up to 15 minutes.
This branch is scoped to OSHA general industry. Construction, mining, maritime variations, state plans, impulse/impact noise, instrument error and enforcement decisions require their controlling rules and competent review.
Why the frameworks cannot be mixed
| Caratteristica | EU daily exposure | OSHA general industry |
|---|---|---|
| Primary result | LEX,8h, logarithmic energy normalization | 5 dB exchange-rate dose and TWA |
| Reference/action quantity | 80/85 dB(A) action values | 50% HCA dose / 100% PEL dose |
| Threshold handling | All documented work noise contributes to energy | 80 dBA HCA and 90 dBA PEL integrations are separate |
| Hearing protection | Excluded for action values; required for limit-value effective exposure | Protector adequacy is a separate evaluation |
The NIOSH 85 dBA REL with a 3 dB exchange rate is a separate US recommendation. It is not relabelled as EU law and is not substituted for OSHA in this worksheet.
Sources and edition boundary
- Consolidated Directive 2003/10/EC, 26 July 2019 — definitions, action/limit values, protector treatment and weekly-exposure conditions.
- UK HSE L108, Controlling noise at work — official multi-period LEP,d/LEX,8h energy formula used as a transparent public implementation.
- OSHA 29 CFR 1910.95 — general-industry occupational-noise requirements and Table G-16.
- Mandatory Appendix A to 29 CFR 1910.95 — Tᵢ, dose, TWA and Table G-16a.
- OSHA Technical Manual, Section III, Chapter 5 — separate 80/90 dBA thresholds and the warning that Appendix A entries above 115 dBA do not imply acceptability.
- ISO 9612:2025, Edition 3 — current occupational-noise measurement methodology; its public scope requires exposure-condition analysis and uncertainty and excludes exposure at the ear with protectors worn.
- ISO 1999:2013, Edition 3 — current noise-induced-hearing-loss estimation standard. Directive 2003/10/EC legally cites the now-withdrawn ISO 1999:1990 definition; this page does not silently rewrite that statutory cross-reference.
- NIOSH Publication 98-126 — separate 85 dBA REL/3 dB recommendation, included only to prevent framework conflation.
Official records checked 13 July 2026. No closed ISO procedure, uncertainty budget or protector-attenuation method is reproduced or guessed.
Questions that prevent unsafe use
Can I enter an instantaneous sound-level-meter reading?
Not unless it is demonstrably representative of the framework-specific segment quantity. EU rows require LAeq,Tᵢ; OSHA rows require the applicable 5 dB-exchange LAVG/dose relationship and instrument settings. A momentary reading does not establish either quantity.
Why is there no “permissible exposure time” result?
The EU Directive sets daily/weekly action and limit values, not a universal safe time. OSHA’s reference duration is one term in a workshift dose calculation and values above 115 dBA are not made acceptable by a short computed time.
Can I subtract an NRR or SNR from the input?
No. The page does not evaluate hearing-protector attenuation. EU action values use unprotected exposure, while its limit value requires effective exposure with individual protection. OSHA protector evaluation likewise requires the applicable method, fit and exposure context.
What if some work periods are missing?
The result is only the contribution of entered rows and cannot support a below-threshold conclusion. Complete and representative workshift data are required.
What about impulse or peak noise?
Peak C-weighted/impulse exposure is a separate quantity and is not inferred from segment dBA levels. Assess it with the controlling framework and suitable instrumentation.
