Drug and Alcohol Testing at Work in Ontario

Ontario has no single law on workplace drug and alcohol testing. The rules come mainly from the Human Rights Code, court and tribunal decisions, and collective agreements.

When testing may be allowed

• Safety-sensitive jobs, where impairment could cause serious harm.
• Reasonable cause: signs of impairment at work.
• Post-incident: after an accident or near miss.
• Return to work: after treatment, as part of an agreed plan.

Random testing

In Entrop v. Imperial Oil (2000), the Ontario Court of Appeal held that random drug testing was not justified, because a positive drug test didn't show current impairment. Random alcohol testing of safety-sensitive employees can sometimes be justified.

Addiction is a disability

An employee with a substance use disorder is protected. Employers must consider accommodation, such as leave for treatment, before discipline or dismissal.

Your rights

• Ask for the written policy.
• Ask why you are being tested.
• Seek advice before signing anything after a positive test.

Sources

• Ontario Human Rights Code
• Entrop v. Imperial Oil Ltd., 2000 CanLII 16800 (ON CA)
• OHRC: drug and alcohol testing

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General Ontario legal information, not legal advice for your matter, and reading it does not create a retainer. Sources checked 16 October 2026: check the current law, forms and dates before you act.

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This article is general information for people in Ontario, not legal advice. Rules, forms and deadlines change, and every situation is different. Check the current rule or speak to a licensed legal professional before you act.