Is a written risk assessment mandatory in Canada, and how often must it be reviewed?

Yes in substance, although the words and review periods depend on the jurisdiction. Federally regulated employers must have a hazard identification and assessment methodology, a record of hazards and a hazard prevention programme that is evaluated at least every three years, with a written evaluation report. Alberta requires a dated written hazard assessment before work begins, repeated when work changes. Ontario and Quebec use their own instruments.

Short answer

• Federal (COHSR Part XIX): a methodology, hazard identification and assessment, record of hazards, preventive measures, training and a programme evaluation at least every three years and whenever conditions or hazard information change. Evaluation reports are kept for six years.
• Alberta (OHS Code Part 2): hazard assessment before work begins, a written report with the date, repeated at reasonably practicable intervals, when a new work process is introduced, when a process or operation changes and before significant alterations. Affected workers must take part.
• Ontario: no general written risk assessment duty in the act, but a written OSH policy reviewed at least annually (more than five workers), a programme, workplace violence risk assessments and written exposure assessments for designated substances.
• Quebec: under the 2021 law modernising the regime, every establishment must have prevention and participation mechanisms; the health and safety committee (20 or more workers) takes part in identifying and analysing risks, and a liaison officer (19 or fewer) makes written recommendations on risk identification. The regulation on these mechanisms took effect on 1 October 2025.
• In every jurisdiction, specific regulations require written assessments for particular hazards, such as confined spaces.

What the federal hazard prevention programme requires

Canada's federal regulations do not use the term "risk assessment", but Part XIX of the Canada Occupational Health and Safety Regulations (COHSR) sets out a complete cycle. The employer develops it with the policy committee, the work place committee or the health and safety representative:

1. Implementation plan with a time frame for each phase.
2. Hazard identification and assessment methodology, using investigation reports, first aid and minor injury records, inspection results, employee reports and the record of hazardous substances. It must set the steps and time frame, the keeping of a record of hazards and when the methodology itself is reviewed.
3. Identification and assessment of each hazard, including ergonomics, considering exposure level, frequency and duration, health effects and existing controls.
4. Preventive measures in this order: elimination (including engineering controls), reduction (including isolation), personal protective equipment, then administrative procedures. A preventive maintenance programme is part of this step.
5. Training of employees on the programme and their hazards.
6. Programme evaluation at least every three years, and also whenever conditions change or new hazard information becomes available, documented in a report kept for six years.

Other federal parts add specific written assessments, for example a confined space assessment by a qualified person, reviewed at least every three years (COHSR Part XI), and investigations of exposure to hazardous substances with a written report kept for 30 years (COHSR ss. 10.4 to 10.6).

Provincial approaches compared

Common mistakes

• Writing a generic risk matrix once and never linking it to incident records, inspections and employee reports, which the federal methodology must use.
• Waiting for the three-year date after a change in process, equipment or layout.
• Doing the assessment without the committee or representative: participation is a legal requirement in federal law and in Alberta.

Related on excodex

• Occupational safety and health in Canada: law, authorities and employer duties
• Workplace risk assessment: process, team, records and review
• Is a safety committee or a worker safety representative required in Canada?

Standards and further reading

• Canada Occupational Health and Safety Regulations, SOR/86-304, Part XIX (Hazard Prevention Program), Part XI and ss. 10.4 to 10.6: https://laws-lois.justice.gc.ca/eng/regulations/SOR-86-304/
• Alberta OHS Code, Alta. Reg. 191/2021, Part 2, ss. 7 to 9: https://kings-printer.alberta.ca/documents/Regs/2021_191.pdf
• Ontario Occupational Health and Safety Act, ss. 25(2)(j) and 32.0.3: https://www.ontario.ca/laws/statute/90o01
• Ontario Regulation 490/09, s. 19 (assessment of designated substances): https://www.ontario.ca/laws/regulation/090490
• Government of Quebec news release on the interim regime and prevention mechanisms (15 October 2024): https://www.quebec.ca/nouvelles/actualites/details/loi-modernisant-le-regime-de-sante-et-de-securite-du-travail-appliquer-le-regime-interimaire-des-maintenant-un-avantage-pour-tous-les-milieux-de-travail-58834
• Government of Quebec news release on the regulation in force from 1 October 2025: https://www.quebec.ca/nouvelles/actualites/details/loi-modernisant-le-regime-de-sante-et-de-securite-du-travail-un-nouveau-reglement-favorisant-la-prevention-des-le-1er-octobre-2025-66137

This article is general occupational safety and health information prepared by the excodex editorial team. It does not replace the applicable legislation, standards, manufacturers' instructions or the assessment of a competent OSH professional or occupational physician.