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In a recent decision, Stewart v. Elk Valley Coal Corp, the Supreme Court of Canada (“SCC”) held that the Alberta Human Rights Tribunal (“Tribunal”) reasonably concluded that a worker who tested positive for drugs following a workplace accident was terminated because he breached the employer’s drug policy and not for discriminatory reasons. This decision is a welcome result for employers faced with safety risks due to substance use in their workplace. We have outlined below the key findings in this case and best practices to follow when implementing policies to address such risks.


Mr. Stewart drove a loader in a mine operated by the employer. The employer had implemented an Alcohol, Illegal Drugs and Medication Policy (“Policy”) with the objective of ensuring safety in the mine. Under the “no free accident” rule in the Policy, employees were expected to disclose any substance dependence or addiction issues before a drug-related incident occurred. If they complied, they would be offered treatment. Conversely, if they failed to disclose and were involved in an incident and tested positive for drugs, their employment would be terminated.

Mr. Stewart used cocaine outside of work. Despite attending a training session on the Policy and signing off on his acceptance of it, Mr. Stewart did not disclose his drug use to the employer. Mr. Stewart was then involved in a workplace accident. After a positive drug test, he then advised the employer that he thought he was addicted to cocaine. The employer subsequently terminated his employment in accordance with the Policy.

Discrimination or Not?

Mr. Stewart brought a human rights complaint alleging discrimination on the ground of disability (drug addiction) by his employer. The main issue before the Tribunal was whether the employer had terminated Mr. Stewart’s employment because of his addiction (a discriminatory reason) or for breaching the Policy (a non-discriminatory reason).

The SCC confirmed that the Tribunal cited the proper test for prima facie discrimination: “complainants are required to show that they have a characteristic protected from discrimination under the Code; that they experienced adverse impact with respect to the service; and that the protected characteristic was a factor in the adverse impact.”

The employer conceded that the first two elements of prima facie discrimination were established. The dispute accordingly centred on the third element – whether Mr. Stewart’s addiction was a factor in his termination. On this point, Mr. Stewart argued that denial is a symptom of addiction and terminating him for failing to disclose his addiction was, in essence terminating him because of his disability. Neither the Tribunal nor the SCC accepted this argument. In her judgment on behalf of the majority, Chief Justice McLachlin wrote:

“While Mr. Stewart may have been in denial about his addiction, he knew he should not take drugs before working, and he had the ability to decide not to take them as well as the capacity to disclose his drug use to his employer. Denial about his addiction was thus irrelevant in this case.”

The Tribunal found that the employer had terminated Mr. Stewart’s employment for breach of the Policy and not because of his addiction. A majority of the SCC agreed that the Tribunal’s conclusion was reasonable. The lower courts had also reached the same finding.


The SCC’s decision demonstrates that employers may implement proactive policies to deter substance use in safety sensitive workplaces provided their objective is safety and not retaliation. Employers who adopt policies of this nature should ensure that they adhere to the following best practices (many of which were undertaken by the employer in this case):

  • the policy should be explicit and easy to understand;
  • employees should have the opportunity to disclose their substance issues to the employer without retaliation before safety is compromised;
  • supervisors should be trained on how to appropriately respond to such disclosures;
  • substance-addicted employees should be reasonably accommodated;
  • employees should receive training to ensure they understand the policy, with the training repeated at regular intervals; and
  • employees should be asked to confirm in writing their receipt, understanding and acceptance of the policy.

Following the above practices will help reduce the risk that an adjudicator will find that the implementation or application of the policy was discriminatory. The policy should also be reviewed regularly and revised as needed to reflect compliance with the law in this area.