Hearing Conservation Program
Noise Dosimetry Mapping Log
Permit-ready field form for documenting personal noise exposure (Lep, Lpeak, Lavg), mapping high-noise zones, and selecting appropriate hearing protection. Compliant with WorkSafeBC OHS Guideline G7.2, CSA Z94.2, and ISO 9612.
This Noise Dosimetry Mapping Log is the primary field instrument for documenting personal noise exposure levels for workers in designated high-noise areas (≥85 dBA TWA). It formalizes the dosimetry survey process: selecting representative employees, deploying Type 2 dosimeters, recording Lep (TWA), Lpeak, and Lavg, and mapping each measurement to a specific zone on the facility layout. All recorded values are compared against the WorkSafeBC 85 dBA action limit and the CSA Z94.2 hearing protector selection criteria. The log also provides a built-in Corrective Action Register and a Supervisor sign-off block to satisfy regulatory record-keeping requirements under OHS Regulation 7.2.
- Noise survey: A walk-through survey must be completed using a sound level meter (SLM) to identify zones with instantaneous levels ≥85 dBA. Mark these zones on the facility map before deploying dosimeters.
- Hearing protection: All personnel entering a logged zone with Lep ≥85 dBA must wear CSA Z94.2‑rated hearing protection (earplugs with SNR ≥28 dB or earmuffs with SNR ≥30 dB).
- Dosimeter calibration: Each dosimeter must be field‑calibrated using an acoustic calibrator (114 dBA @ 1 kHz) immediately before and after the shift. Record calibration values in the log.
- Worker training: Workers selected for dosimetry must be instructed to carry on with normal duties and not tamper with the microphone placement (collar zone, no wind‑shield removal).
Audit / Dosimetry Mapping Matrix
| Pass / Fail | Zone / Location | Worker ID | Lep (dBA TWA) | Lpeak (dBC) | Lavg (dBA) | Hearing Protection Required? |
|---|---|---|---|---|---|---|
| ☐ Pass ☐ Fail | Zone A — Press Line | W‑1024 | 88.2 | 132.1 | 86.7 | Yes — SNR ≥ 30 dB |
| ☐ Pass ☐ Fail | Zone B — Welding Bay | W‑1087 | 83.4 | 118.6 | 81.9 | No (<85 dBA) |
| ☐ Pass ☐ Fail | Zone C — Compressor Room | W‑1102 | 92.7 | 139.4 | 91.0 | Yes — dual protection |
| ☐ Pass ☐ Fail | Zone D — Assembly Line | W‑1055 | 79.1 | 112.3 | 77.8 | No (<85 dBA) |
Thresholds per WorkSafeBC G7.2: Action level = 85 dBA TWA; Exposure limit = 90 dBA TWA. Exchange rate: 3 dB.
Incident / Corrective Action Register
| Date / Time | Item # | Safety Issue Identified | Corrective Action Taken | Assigned To |
|---|---|---|---|---|
| 2026-04-10 / 14:30 | 001 | Zone C worker recorded Lep 92.7 dBA — dual protection not being worn | Immediately fitted with earplugs + earmuffs; retraining scheduled | J. Bachand (Shift Sup.) |
| 2026-04-11 / 08:15 | 002 | Dosimeter #2043 failed post‑shift calibration (drift >0.5 dB) | Dosimeter removed from service; data flagged as invalid; re‑survey Zone A on next shift | L. Tran (EHS Tech) |
| ___ / ___ / _____ | _______ | _______________________________ | _______________________________ | _______ |
By signing below, the supervisor or designated competent person verifies that all dosimetry measurements were collected using calibrated instruments, that exposure values have been compared against the WorkSafeBC action limit of 85 dBA TWA, and that appropriate hearing protection has been assigned to each high-noise zone. This log satisfies the record-keeping requirements of OHS Regulation 7.2.