Can’t measure impairment, can’t manage safety risks, won’t hire medical cannabis user.

Human Rights, Discrimination and Accommodation | Workplace Safety
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If you are an employer, you may have been worried about the recent legalization of recreational cannabis, wondering what it means for your workplace. Does that mean you have to accommodate cannabis users? What about those using medical cannabis due to disability?

As you may already know, employers are required to accommodate individuals to the point of “undue hardship” where the need for accommodation relates to a ground protected by human rights legislation, such as disability. Aside from undue hardship, another exception is a bona fide occupational requirement (“BFOR”), i.e. a skill or characteristic that is essential to a job, without which the job cannot be performed. Both undue hardship and BFOR are high standards to meet. As we always say, accommodation of medical cannabis used to treat a disability should be treated the same way as any other accommodation.

Recently, the Supreme Court of Newfoundland and Labrador (the “Court”) upheld an arbitration decision finding an employer’s refusal to hire a medical cannabis user was justified since the employer could not accommodate without undue hardship in International Brotherhood Lower Churchill Transmission Construction Employers’ Assn. Inc. v IBEW, Local 1620 (Tizzard), Re,. The Union applied to the Court for judicial review. The Court dismissed the application.


The employer offered the grievor a labourer position, if he passed mandatory pre-employment drug and alcohol screening. Although his test results were positive, the employer then found out that the grievor used medical cannabis every evening for pain management due to osteoarthritis and Crohn’s disease.

The employer reviewed information provided by the grievor’s doctor and retained a medical consultant for independent advice. The employer then refused to hire the grievor based on his use of medical cannabis.

The Union brought a grievance alleging that the employer failed to accommodate the grievor’s disability. The employer argued that it reached the point of undue hardship: the position was safety sensitive and the grievor’s use of medical cannabis after work hours resulted in unmanageable safety risks to the jobsite.


The arbitrator found the position was safety sensitive, that the grievor had a disability, and that requiring a labourer to perform work safely was a bona fide occupational requirement. In order to determine whether the employer reached the point of undue hardship, the arbitrator considered a broad range of medical expertise on the effects of cannabis use. In particular, the following questions were central to this analysis:

  1. What is the time frame for impairment? How long after cannabis use can an individual safely work in a safety sensitive position?
  2. How can employers test for cannabis impairment?

The arbitrator found that there is no scientific consensus regarding the time frame for impairment: the length of cognitive impairment can exceed four hours after ingestion and can sometimes exist for up to 24 hours after use.

With respect to testing for cannabis impairment, the arbitrator found that “[t]here currently are no readily available testing resources within the Province of Newfoundland and Labrador to allow an employer to adequately and accurately measure impairment arising from cannabis use on a daily or other regular basis”.

The arbitrator concluded that “if the Employer cannot measure impairment, it cannot manage risk” and denied the Grievance as follows:

The Employer did not place the Grievor in employment … because of the Grievor’s authorized use of medical cannabis as directed by his physician. This use created a risk of the Grievor’s impairment on the jobsite. The Employer was unable to readily measure impairment from cannabis, based on currently available technology and resources. Consequently, the inability to measure and manage that risk of harm constitutes undue hardship for the Employer.


This decision is encouraging for employers with safety sensitive workplaces: the employer’s inability to effectively measure and monitor residual impairment from medical cannabis used outside of work hours meant that the employer was unable to manage safety risks, and that constituted undue hardship. While this decision is not binding, employers in Ontario could potentially use the reasoning to support their case if they face similar situations.

Employers should keep in mind that this decision is based on the position being safety sensitive, and the conclusion may have been different otherwise. Just because a workplace or industry is considered safety sensitive does not mean that the position itself is safety sensitive. When dealing with a specific scenario, employers should assess the particular position. If the position is safety sensitive, then that will inform the undue hardship analysis.

Moreover, during the accommodation process, some hardship is expected – the threshold is undue hardship and the bar is high. In this case, the magnitude of the safety risks was critical to finding undue hardship. Simply put, since the employer could not measure cannabis impairment (including residual impairment), the employer could not manage the safety risks arising from it, and therefore, the employer faced undue hardship.  

As we always say, it is crucial to have an accommodation policy and process. Our firm regularly assists employers in drafting policies to protect them as strongly as possible. As an employer, if you cannot accommodate without undue hardship, clearly explain this to the employee or potential employee, and be prepared to show why this is the case. We also work with employees during the accommodation process and address potential claims if the process fails.

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