Inability to Measure Cannabis Impairment Justifies Zero-Tolerance Policy

Written by John R. Gilmore and Matthew J. Macdonald

The inability to measure and mitigate impairment from medical cannabis means employers can avoid accommodation requests from employees, according to the Newfoundland and Labrador Supreme Court in IBEW, Local 1620 v Lower Churchill, 2019 NLSC 48 [Lower Churchill]. This important decision is useful to safety-sensitive employers trying to meet both their safety and human rights obligations.

Employers that operate safety-sensitive work environments have to navigate the complicated world of human rights obligations to not discriminate against employees who use medical cannabis, while attempting to satisfy various legal requirements to ensure a safe workplace environment. Under human rights laws, when a reasonable and good faith employer policy causes someone an adverse effect due to a disability, the employer must demonstrate undue hardship resulting from the required accommodation.

In Lower Churchill, an employer was constructing power equipment in a highly safety-sensitive environment. An employee suffered pain due to osteoarthritis and Crohn’s disease. After unsuccessfully trying conventional therapies, he was prescribed medical cannabis which provided greater relief.

The employee disclosed his use of medical cannabis, after which he was not used for various jobs that came available. The employer association stated its reason for not using the employee was due to concerns about the potential for impairment while performing safety-sensitive duties. The employee and his union grieved the refusal to use him on various jobs, despite his seniority status and entitlement under the collective agreement to work on these projects. It was commonly accepted that the employee had a disability that required cannabis as a treatment and that there were no non-safety-sensitive jobs available.

There was competing expert evidence before the Arbitrator as to the effects of cannabis and how quickly any impairment might dissipate. The experts included competing general practitioner opinions, a pharmacologist/toxicologist, and a pain management specialist. The Court accepted that based on the expert evidence, the Arbitrator reasonably concluded that:

• medical cannabis can impair the ability of a worker to function safely in a safety-sensitive environment;
• the impairment can last up to 24 hours;
• the using employee may be unable to determine that they remain impaired; and
• there are no available testing methods to accurately determine impairment from cannabis use in the workplace.

The employer based its decision to not employ the employee on evidence of possible impairment that could not be accurately measured or mitigated. The resulting impact of possible impairment on the employer’s safety obligations would be undue hardship. As a result of meeting the undue hardship standard, the employer was discharged of its duty to accommodate under human rights laws. The lack of non-safety-sensitive positions and the supportive expert opinion evidence on possible impairment was key to the success defence of the employer. Lower Churchill provides one more line of defence to safety-sensitive employers trying to meet their safety obligations without being liable in a human rights claim.