Workplace Noise Assessments for Employers in Quebec
Employers in Quebec whose workers are exposed to noise are subject to a specific obligation under the occupational health and safety regulation. Every five years, and after any change that may increase exposure, a workplace noise assessment is required in every establishment, regardless of size. The assessment identifies the work situations in which exposure may exceed the limits and determines the noise control measures. The measurements are made by a qualified person and documented in a report the regulation requires.
Measurements of noise exposure have traditionally been carried out by an occupational hygienist. The noise control measures the regulation now requires are a different matter. Identifying the dominant sources and designing the measures that reduce their noise is acoustical engineering and calls for a specialized professional.
Quebec Occupational Health and Safety Regulation for Noise
The obligation is set out in the Règlement sur la santé et la sécurité du travail (RSST), section XV, as rewritten in June 2023, and is enforced by the Commission des normes, de l’équité, de la santé et de la sécurité du travail (CNESST). The regulation specifies the exposure limits, the order in which reduction measures must be considered, the measurement standards, and the records the employer must keep.
| Limit | Value | What it addresses | Typical situation |
|---|---|---|---|
| Daily exposure (LEX,8h) | 85 dBA | Sound energy received over a full shift; a short exposure to a high level and a long exposure to a lower level count the same | A production floor, a woodworking shop, a compressor room |
| Peak sound pressure (Lp,Cpeak) | 140 dBC | A single event loud enough to damage hearing in an instant, whatever the day’s average | A hammer blow, a pneumatic tool exhaust, a dropped metal part |
Where the assessment identifies a work situation in which exposure exceeds a limit, the regulation now requires that measures to reduce sound levels at the source be investigated first. Previously, employers commonly relied on hearing protection by default.
The noise report must be posted in the workplace and kept in the employer’s files for at least ten years.
Workplace Noise Assessment for Employers
A compliant assessment typically includes the following work:
- Noise exposure evaluation — sound levels are mapped across the establishment and personal dosimeters are worn by representative workers over full shifts; daily exposure is calculated for each work situation and compared with the limits
- Diagnostic measurements — where exposure exceeds a limit, specialized measurements identify the dominant sources, their contribution at each work position, and the deficiencies in the existing installation, as the basis for noise control design
- Noise control design, where required — Sonvera works with the plant’s engineering and maintenance staff to identify the most appropriate measures, from equipment modification to the installation of engineering noise controls such as enclosures, room treatment, and noise barriers, selected for what can realistically be implemented within the production, maintenance, and safety constraints of the plant
- Verification measurements — after the measures are implemented, exposure is measured again and the results are documented in the noise report
The result is a report that gives management a clear basis for decision: in which work situations exposure exceeds the limits, which sources are responsible, and what the practical noise control measures are, with their expected reduction and order of cost. The same measures often reduce the sound levels at neighbouring dwellings, which matters where the facility holds an environmental authorization.
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