One in Four Canadian Cannabis Users Had Used Before or During Work — and They Looked Different From Off-the-Clock Users | Research

The takeaway

25% of Canadian workers who used cannabis in the past year reported using before or at work, and workplace users were more likely to use daily, use high-THC products, and use for medical purposes.

Employers, policy makers, or workers navigating cannabis in the workplace — especially in Canada's post-legalization environment.

25%
Of Canadian workers who used cannabis in the past year had used before or at work

What the researchers found

In a survey of 1,651 Canadian workers conducted in June 2018 — just months before recreational legalization — a quarter of those reporting past-year cannabis use said they'd used before or at work. These workplace users weren't just recreational users who happened to be at work. They had a distinct profile.

Compared to off-the-clock cannabis users, workplace users were significantly more likely to use cannabis daily, use for medical or mixed medical-recreational purposes, and prefer high-THC products. Several personal factors predicted workplace use: younger age, being male, lower education, poorer self-rated health, and having a physically demanding or monotonous job.

The medical use dimension complicated the picture. Some workplace cannabis use wasn't reckless — it was people managing pain, anxiety, or other conditions during work hours. The policy challenge of distinguishing impaired use from therapeutic use was already present before legalization formalized it.

Why it matters

Workplace cannabis use is the third rail of legalization policy. This study put numbers to it for the first time in Canada and found the rate was substantial — 1 in 4 users. The finding that workplace users were more likely to be medical users adds nuance: workplace drug policies designed around recreational intoxication may inadvertently penalize workers managing legitimate health conditions.

The pre-legalization timing makes this a baseline. Whether these patterns changed after recreational legalization became a critical follow-up question.

The numbers in context

• 25% of past-year cannabis users reported workplace use

• 1,651 Canadian workers surveyed (June 2018)

• Workplace users more likely to: use daily, use high-THC, use for medical purposes

• Risk factors: younger, male, lower education, poorer health, physically demanding jobs

How the study worked

Cross-sectional survey of 1,651 Canadian workers collected in June 2018. Multinomial logistic regression comparing three groups: past-year workplace cannabis users, past-year non-workplace users, and non-users. Controlled for sociodemographic, health, and work-related factors.

Who was studied

N=1,651 Canadian workers, diverse age and education levels, surveyed in June 2018.

What this study cannot tell us

Self-reported data likely underestimates workplace use due to stigma and fear of consequences. Cross-sectional design cannot determine whether work characteristics cause cannabis use or vice versa. Single time point before legalization — patterns may have changed. Online survey sample may not represent all Canadian workers.

How to read the evidence

Large cross-sectional survey with appropriate statistical methods. Representative of Canadian workers but limited by self-report and single time point.

When this study was published

Published in 2021 using June 2018 data — collected months before Canadian recreational legalization. A baseline snapshot.

The bigger picture

This was the first large Canadian dataset on workplace cannabis use, collected at a unique moment — right before legalization. Combined with RTHC-00061 (the NIOSH commentary on research gaps), it confirmed that workplace cannabis use was substantial and that existing testing and policy frameworks weren't designed for this reality.

Replication

Not stated in abstract.

Funding

Not reported in abstract.

Conflicts of interest

Not reported in abstract.

Questions still open

Did workplace cannabis use increase after Canadian legalization?
How should workplace policies differentiate between medical and recreational cannabis use?
Are workers in safety-sensitive positions using cannabis at similar rates?

Common questions

How many workers use cannabis at work?

In this Canadian survey, 25% of workers who used cannabis in the past year had used before or during work. They tended to be daily users who used for medical purposes.

Why do people use cannabis at work?

Many workplace users reported medical or mixed medical-recreational use — managing pain, anxiety, or other conditions during work hours. It wasn't solely recreational use.

Read the original research

Patterns and correlates of workplace and non-workplace cannabis use among Canadian workers before the legalization of non-medical cannabis.

Drug and alcohol dependence, 218, 108386

Drug and Alcohol Dependence is a well-respected journal focusing on substance use and its effects.

View on PubMed ↗Publisher’s paper ↗

Citation

Carnide, Nancy; Lee, Hyunmi; Frone, Michael R; Furlan, Andrea D; Smith, Peter M. (2021). Patterns and correlates of workplace and non-workplace cannabis use among Canadian workers before the legalization of non-medical cannabis.. Drug and alcohol dependence, 218, 108386. https://doi.org/10.1016/j.drugalcdep.2020.108386