Are pre-employment and periodic medical examinations required for workers in Canada?

Not as a general rule. Canadian OSH law does not require every worker to have a pre-employment or periodic medical examination. Examinations are required for specific exposures and jobs, for example where a federal assessment of a hazardous substance shows they are needed, or under Ontario's designated substances regulation for asbestos, benzene, lead, silica and other listed agents. Any other medical requirement must be justified as a bona fide occupational requirement under human rights law.

Short answer

• No blanket duty: neither the Canada Labour Code nor the provincial acts checked (Ontario, Alberta) set routine pre-employment or periodic examinations for all workers.
• Federal hazardous substances: if the qualified person's report recommends medical examinations, the employer consults a physician; if the physician confirms the need, the employee may not handle the substance until a physician acceptable to the employee declares them fit (or fit with restrictions). The employer pays (COHSR s. 10.7).
• Ontario designated substances (O. Reg. 490/09): for asbestos, benzene, coke oven emissions, isocyanates, lead, mercury and silica, where an assessment shows a worker's health may be affected, the control programme must include pre-placement, periodic, acute exposure and exit examinations under the provincial Code for Medical Surveillance.
• Other specific rules: for example, federal diving rules require every diver to have had a medical examination within the last two years and to be declared fit to dive (COHSR s. 18.7), and Alberta requires employer-paid audiometric tests for workers exposed to excess noise: a baseline within 6 months, a second test within 12 months of it, then at least every second year (OHS Code s. 223). Sector regulations (transport, mining, radiation work) add their own; check the rules for your sector.
• Human rights limits: an employer may refuse or limit employment on medical grounds only where it is a bona fide occupational requirement and accommodation would cause undue hardship (Canadian Human Rights Act s. 15 and provincial codes).

How the federal rule works

Under Part X of the Canada Occupational Health and Safety Regulations (COHSR), when an employee's health or safety is likely to be endangered by exposure to a hazardous substance, the employer appoints a qualified person to investigate. The qualified person's signed report covers the properties of the substance, exposure routes, health effects, quantities, controls and the likely exposure, and it may recommend medical examinations. The report is kept for 30 years.

The medical step then follows a set order:

1. The employer consults a physician on whether an examination is necessary.
2. If the physician confirms it, the employee does not handle the substance until a physician acceptable to the employee has examined them and declared them fit, or fit with specified restrictions.
3. If there are restrictions, the employer applies them.
4. A copy of the physician's decision is kept with the qualified person's report, and the employer bears the cost.

This is a risk-based approach: the examination follows from the exposure assessment, not from the job title or headcount.

Ontario's designated substances

Ontario lists 11 designated substances: acrylonitrile, arsenic, asbestos, benzene, coke oven emissions, ethylene oxide, isocyanates, lead, mercury, silica and vinyl chloride. Where one is present and a worker is likely to be exposed, the employer must make a written assessment. If it shows that a worker's health may be affected, a control programme is required, and for seven of the substances it must provide medical surveillance at defined points.

The examining physician tells the worker and the employer whether the worker has an occupational illness from the substance and whether they are fit, fit with limitations or unfit to continue working in exposure, and the employer must act on that advice. For acrylonitrile, arsenic, ethylene oxide and vinyl chloride, a worker who was exposed may ask for an examination in defined circumstances.

Practical points for employers

• Base any medical requirement on a documented exposure or job-demand assessment, and keep it proportionate.
• Keep medical results confidential: federal committees, for example, may see reports and studies but not personal medical records without consent.
• Plan accommodation when a worker is found fit with restrictions.
• Remember that workers arriving from countries such as Türkiye, where işe giriş and periodic examinations are routine, may expect them; explain the Canadian approach.

Related on excodex

• Occupational safety and health in Canada: law, authorities and employer duties
• Must an employer in Canada appoint a safety professional or an occupational physician?
• Is a written risk assessment mandatory in Canada?

Standards and further reading

• Canada Occupational Health and Safety Regulations, SOR/86-304, ss. 10.4 to 10.7: https://laws-lois.justice.gc.ca/eng/regulations/SOR-86-304/
• Ontario Regulation 490/09, Designated Substances, and the Code for Medical Surveillance for Designated Substances (2019) it refers to: https://www.ontario.ca/laws/regulation/090490
• Ontario Occupational Health and Safety Act, s. 26: https://www.ontario.ca/laws/statute/90o01
• Alberta OHS Code, Alta. Reg. 191/2021, s. 223 (audiometric testing): https://kings-printer.alberta.ca/documents/Regs/2021_191.pdf
• Canadian Human Rights Act, s. 15: https://laws-lois.justice.gc.ca/eng/acts/H-6/section-15.html

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.