Reducing stigma, understanding accommodation can help employees, say experts
Medical cannabis might be helping workers get back to work, according to a study published this year.
Published in the Journal of Workplace Behavioral Health, it examined more than 20 million U.S. workers using federal labour data from 1990 to 2025. Researchers looked specifically at workers' responses on whether they had missed work and why, such as for medical or injury reasons, and then compared those absences before and after states brought in medical and recreational cannabis laws.
They found that workers in states with medical cannabis laws were 6.9 per cent less likely to report missing work because of illness, injury or a medical issue. States with recreational cannabis laws, however, saw no real difference.
“At a more granular level, the absenteeism-reducing effects of medical cannabis decriminalization are concentrated in occupations and industries in which chronic pain, physical strain, and job-related stress are plausibly important determinants of missed work,” says the study.
While there may be a correlation between absences and medical cannabis legalization, the study notes it doesn't show causation, and workers weren't asked if they were using medical cannabis.
Stigma vs. support
These promising results suggest HR and employers should be supportive about the use of medical cannabis by employees if it can lead to fewer absences.
Shawna Meister, associate director of innovation and evidence in practice at the Canadian Centre on Substance Use and Addiction, says it’s important for employers to create an open environment where employees can come forward and the employer "has encouraged the opportunity to talk about accommodations.”
While stigma around substances in general still exists in the workplace, Meister says it isn't the only factor why employers might struggle with conversations about substance use at work.
"Stigma is certainly one of the risks for preventing, probably, further cooperation or accommodations on challenges, but there's also workplace culture, there's also privacy and confidentiality around medical conditions. So, a number of factors come into play," she says.
The most common mistakes that employers and HR make are treating medical cannabis like recreational cannabis, or assuming its use automatically means impairment, according to Ronald Minken, an employment lawyer at Minken Employment Lawyers.
Meister explains that medical cannabis can contain tetrahydrocannabinol (THC), which can cause impairment, and cannabidiol (CBD), which is non-impairing.
"Just because we use the term ‘medical cannabis,’ what's really more important is understanding the content of that cannabis," she says.
Duty to accommodate and cannabis
According to the Ontario Human Rights Commission's policy statement, medical cannabis in the workplace should be treated the same as any other prescribed medication. Employees can be accommodated for medical cannabis if it relates to a disability and doesn't interfere with health, safety or their ability to perform their duties.
Minken says that while medical cannabis can trigger the duty to accommodate, it doesn't automatically give employees the right to use cannabis at work.
"The employer accommodates the disability-related need, not an unrestricted right to use cannabis in any manner the employee chooses," he says.
Accommodation has to be done through a case-by-case assessment, says Minken: "One size fits all does not work.”
Those accommodations can look like adjusted work hours, modified tasks or temporary changes to duties, he says. The goal is for employers to find a "workable solution," not necessarily one that means "accepting the employee's preferred solution."
To figure that out, employers can ask for information about an employee's limitations and restrictions, such as how treatment might affect alertness or judgment, but they aren't entitled to a full diagnosis or medical history, Minken says.
"Relevant questions that an employer may ask may include: ‘Is there a disability-related need requiring accommodation? Does the treatment create cognitive, physical or behavioural limitations? Could it affect alertness, judgment, coordination, reaction time or concentration? When might those effects occur?’”
A Quebec arbitrator recently ruled in favour of Air Transat’s zero-tolerance cannabis policy for flight attendants.
Balancing human rights and safety
Employers can also create policies around medical cannabis use. However, Minken warns policy can become a compliance risk if it's "drafted in a moralistic or punitive way." A policy should cover all substances, not single out cannabis, and sit within a broader fitness-for-duty framework, he says.
Ultimately, it isn't a choice between human rights and workplace safety, says Minken.
"A proper accommodation process would respect both… employers should focus on functional abilities, reliable medical information, essential duties and real safety risks. And if they avoid assumptions and engage in an individual process, they're much more likely to reach a lawful and workable result and, of course, avoid a human rights application.”
