Medical cannabis users may find themselves wondering if they are required to disclose their medical cannabis use to their employer.

There is no overarching legal requirement or principle in employment law in Ontario that workers disclose the use of medical cannabis to their employer. That being said, it is not yet entirely clear, but workers may have a duty to disclose such information under the Occupational Health and Safety Act(OHSA).1 This is due to section 28(1)(d) of the OHSA which states that a worker shall report to his or her employer or supervisor any contravention of OHSA or the existence of any hazard of which he or she knows.

It is unlikely to be disputed that the consumption of cannabis has the potential to impair consumers. The degree of impairment will be, in part, dependant on the type of medicinal cannabis being consumed. For instance, some cannabis products high in CBD are believed or described as not producing the psychoactive effects that THC does and therefore would not be expected to impair users in the same manner. Of course, patients should always consult with their physicians or healthcare professionals before consuming any cannabis products to properly understand the likely or possible effects.

Ultimately, workers do not have a right to be impaired in the workplace where impairment may endanger their own safety, the safety of co-workers or the safety of others (such as customers). When being fit for duty is a bona fide occupational requirement, such as in safety-sensitive work environments, there is an onus on the worker to ask their health care provider about the likely effects of their prescribed cannabis, and to bring any concerns to the employer’s attention.

For employers, there are several obligations including to keep their employees safe and to ensure that they do not discriminate. Section 25(2)(h) of the OHSA imposes a duty on employers to take every precaution reasonable in the circumstances for the protection of a worker. Under the Human Rights Code, employers have a duty to accommodate workers who consume cannabis for medical purposes. However, if an employee needs accommodation in this regard, in order to obtain it, they must first request it. It is important to note that a lack of awareness of a disability and corresponding need to consume medical cannabis will, in most cases, relieve an employer of any duty to accommodate. This principle has been reaffirmed in arbitration cases across the country. For example, in Alphair Ventilating Systems Inc. and USW, Local 9074 – 062 the arbitrator stated that the employee contains the knowledge and control of personal health information and it is their responsibility to furnish meaningful medical information if he/she requires some kind of accommodation.

To conclude, there is no requirement that workers disclose their use of medical cannabis to their employer; however, workers have a duty to report hazards in the workplace under the OHSA, including situations where impairment induced by their medication may endanger their own safety or the safety of their co-workers. Moreover, failure to disclose the use of cannabis for medical purposes may relieve employers of any duty to accommodate.

1Occupational Health and Safety Act, R.S.O. 1990, c. O.1.

2Alphair Ventilating Systems Inc v United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service Workers Union, Local 9074-06, 2014 CanLII 22977 (MB LA).

This article was authored by George Hamzo, Jacob Damstra, and Jeffrey Risdon. It was originally published by Lerners LLP.