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Uncertainty Lies Ahead in Testing for Cannabis Impairment at Work

Posted On: November, 30 2004

As the new recreational cannabis laws have rolled out over the past month, there’s been a lot of discussion over how difficult it is to determine whether someone is impaired by the drug. This is because it is not clear how much marijuana in one’s system results in impairment, or how long that impairment lasts, and because someone can test positive for marijuana in their system days or even weeks after using it.

For employers who suspect that an employee is impaired at work, even in safety-sensitive positions, courts have ruled that neither pre-employment testing nor random drug testing is permissible. However, after a workplace incident occurs, employers can require that the employee undergo a drug and alcohol test.

An arbitral decision released earlier this year by Arbitrator Daniel P. Randazzo in Airport Termination Services Canadian Company v. UNIFOR, Local 202, 2018 CanLII 34078 (CA LA) highlights the difficulties in testing for marijuana after a workplace incident has occurred.

The case concerned a grievor who worked in a safety-sensitive role as a ramp agent at Pearson Airport. The grievor consumed between 2 and 4 grams of medical marijuana every day after work for a back pain issue, meaning there was 12 hours between his cannabis use and the start of his shifts. After he was involved in an accident at work that resulted in damage to a plane, he was required to undergo a drug and alcohol test. He was first suspended for two days, and later the results of his urine test came back positive for marijuana metabolites.

Following meetings with his union and employer, the grievor was given a warning letter which required him to find alternatives to medical marijuana, and to admit that he had a substance abuse problem and enter into a program including counselling and random drug testing. He did not agree to these conditions, and as a result, he was terminated with cause.

The Arbitrator heard from two doctors who offered conflicting evidence regarding how long the grievor would have been impaired for after consuming medical marijuana every day after his shifts. Arbitrator Randazzo found that there was no evidence that the grievor was impaired during the workplace accident; that the employer failed in its duty to accommodate the grievor; and that the with-cause termination violated that Canadian Human Rights Act and the collective agreement. The Arbitrator ultimately made an order reinstating the grievor in the workplace.

The same result will likely not apply where a worker in a safety-sensitive position admits to consuming cannabis at work.

In a recent decision before the Ontario Human Rights Tribunal, the applicant admitted to smoking two grams of marijuana during the work day: Aitchison v. L & L Painting and Decorating Ltd., 2018 HRTO 238. In Aitchison, the Tribunal found that the applicant’s admission was enough to find that he was impaired based in part on the expert medical evidence presented in the case regarding the immediate effects of the drug. The Tribunal further concluded that the employer did not need to produce actual evidence of impairment before taking some kind of action, such as terminating the employee pursuant to its zero-tolerance drug policy.

Although we have some early indications for how an arbitrator and a member of the Human Rights Tribunal may approach this issue, it is not yet clear how Ontario courts will rule on the same kinds of questions relating to cannabis-related impairment at work.


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