Fired for Addiction or a Failed Drug Test in Ontario

Losing your job over substance use is loaded with shame, and employers often present it as a simple case of breaking the rules. The law is more nuanced. Addiction is recognized as a disability in Ontario, which means a dismissal tied to it can be discrimination, and a blunt "zero-tolerance" policy is not the trump card employers think it is.

Is addiction a disability under the Human Rights Code?

Yes. Ontario law treats a genuine dependence on drugs or alcohol as a disability, the same protected ground that covers physical and mental-health conditions. That triggers the employer's duty to accommodate: before it disciplines or dismisses you for addiction-related conduct, it generally has to consider measures like a leave for treatment, a modified return, or a last-chance agreement, up to the point of undue hardship. Casual or recreational use is different; the protection is for dependence.

Can you be fired for failing a drug or alcohol test?

Not automatically. The leading case is Stewart v. Elk Valley Coal Corp. (2017 SCC 30), where a worker in a safety-sensitive mine was fired after a workplace accident and a positive cocaine test. The Supreme Court accepted that addiction is a protected disability, but on the facts found he was dismissed for breaching the drug policy (specifically for not disclosing his use before the accident, something the tribunal found he was capable of doing), not because of his addiction. The case cuts both ways: it confirms addiction is protected, but it also means the key question is whether you were fired because of the disability or for distinct, controllable conduct.

The employee's side: connecting the dismissal to the addiction

You generally have to show your addiction was a factor in the decision. In Lenting v. Huron Tire (2021 ONSC 8026), the court found the employee had not established that his drug addiction was even a factor in his termination, and noted the employer had in fact accommodated him, so the Human Rights Code claim failed. The lesson is not that addiction claims are weak, but that the link between the disability and the dismissal has to be made out with evidence, which is exactly where medical documentation and a record of your requests for help matter.

The employer's side: a policy is not a free pass

On the other hand, an employer cannot simply wave a zero-tolerance policy and avoid its obligations. In Volchoff v. Wright Auto Sales Inc. (2015 ONSC 8029), the employer alleged the worker was intoxicated at work and had driven company vehicles while impaired, and pointed to its zero-tolerance alcohol policy. The court was not satisfied the allegations justified a for-cause dismissal, and awarded the employee reasonable notice. A policy sets expectations, but the employer still has to prove the misconduct and, where addiction is involved, still owes the duty to accommodate.

Where the line is: safety and real harm

There are limits. Where substance use in a safety-sensitive role causes real danger or damage, dismissal can be justified even after accommodation is considered. In Dziecielski v. Lighting Dimensions Inc. (2013 ONCA 565), an employee drank during a lunch break, drove a company truck while impaired, lost control, and caused serious injury and the vehicle's destruction; the Court of Appeal upheld the dismissal. The difference between that and a case like Volchoff is the seriousness and the actual harm, not merely the existence of a policy.

What should you do if you were fired over substance use?

1. 1.If addiction is part of the picture, get it documented medically and, where you can, disclose it and ask for accommodation in writing.
2. 2.Keep records of any treatment, requests for help, and how the employer responded.
3. 3.Do not sign a release or admit "just cause" on the spot; these cases are more complicated than they look.
4. 4.Get advice. A free review can tell you whether the dismissal was discriminatory or a wrongful dismissal owing severance.

This sits at the crossroads of the duty to accommodate, a dismissal tied to a medical condition, and whether the employer really had just cause. If the cause claim fails, you are owed your full severance, and if the dismissal was tied to your disability, you may have a human rights claim on top.

About the Author

Omar Haddad

Legal Writer, Mirza Law

Omar Haddad is a legal writer at Mirza Law in Toronto. He writes about termination, medical and disability leave, and what the law protects when an employee is let go.

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