spent the past few years discussing “weed in the workplace” or, more
accurately, how the workplace will be impacted by both medicinal and
recreational marijuana. In our presentations, we often discuss the four
types of users that employers can expect to encounter:
Each type raises different issues, and the way employers deal with them must
be different. Some require accommodation, others do not.
readers will know, there is a duty to accommodate disability, which
includes medication, but any duty to accommodate is only to the extent
of “undue hardship.” In most cases, we are focused on financial cost.
However, when we talk about allowing an employee who is using medicinal
marijuana to attend at work, the inquiry usually focuses on any health
and safety risks to the employee, their colleagues, and anyone else.
because it is often difficult to measure impairment caused by cannabis,
and even more difficult to predict the extent of impairment in the
future, this is often an extremely difficult exercise. We have not seen
much case law that assesses this in a detail, although we will
undoubtedly be seeing more as we move forward.
One recent arbitration case took this issue on. In Lower Churchill Transmission Construction Employers' Association and IBEW, Local 1620, the
grievor suffered from osteoarthritis and Crohn's disease and was
medically approved to use cannabis to treat his condition. He testified
that he consumed 1.5 grams every night, which was inhaled by
vaporization. According to the evidence, his prescription was for a THC
level of less than 20 per cent. His evidence was that he would not have
any signs of impairment on the following morning.
grievor applied for jobs as a utility worker and as an assembler on the
Lower Churchill project, where he had worked before for other
employers. He disclosed his use of medicinal marijuana, and he did not
get either job. The union alleged that he was well-qualified for both
positions and this was a failure to properly accommodate his use of
The employer defended its decision by asserting that
• the positions were safety-sensitive
• it had a legal obligation to ensure a safe workplace
• it was not feasible to accurately assess the degree and length of impairment that would be caused by the use of cannabis
safety risk that would be created by allowing the grievor to work while
he was using medical cannabis would constitute undue hardship.
assessing the evidence, the arbitrator noted that the authorizing
physician had made what was apparently her standard recommendation: That
patients avoid activities such as driving for four hours after
inhalation. The evidence was that she did not think that his job
performance would be affected, since he would be inhaling the cannabis
in the evening and not working until the following day.
the arbitrator ruled in favour of the employer. First, he agreed that
both positions were accurately described as safety-sensitive. Next, the
arbitrator accepted that the duty to accommodate includes some
assumption of risk by the employer, and that in order to assess whether
undue hardship existed, an individualized assessment was required.
we always tell employers, they are entitled to reasonable medical
information that would disclose the extent of impairment or, framed
differently, the potential impact on their ability to work safely.
the doctor’s opinion that the grievor would only be impaired for four
hours, the arbitrator took note of Health Canada's published information
indicating that impairment from THC can last for more than 24 hours.
arbitrator appears to have been particularly swayed by the inability to
accurately measure the impairment of the grievor, agreeing that this
was a significant concern for someone working in a safety-sensitive
position while using medical marijuana.
unavailability of testing to measure impairment — along with the
difficulty of finding people who could reliably observe and measure
impairment of judgment, motor skills and mental capacity — created a
risk that was too significant, in the view of the arbitrator. As he
employer did not place the grievor in employment at the project 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.”
is likely to be the first of many arbitral judicial positions that
attempts to assess this issue. If the technology evolves so that
impairment is more readily measurable, the analysis is likely to change.
Employers should certainly not take this decision to mean that they can
refuse to employ any individual who is using medicinal marijuana, even
if the position is safety-sensitive.
the arbitrator recognized, every situation must be assessed based upon
its own particular circumstances. However, this decision does provide
some guidance with respect to accommodation of medicinal marijuana in
the context of employment.