A new study conducted by researchers at the University of Toronto, University at Buffalo, and Toronto Rehabilitation Institute challenges the effectiveness of zero-tolerance employment policies for workers who use marijuana off the clock. The study found that workers who consume cannabis outside of work are no more likely to experience workplace injuries compared to those who do not consume cannabis at all. However, the study also revealed that individuals who indulge in marijuana during work hours are nearly twice as likely to be involved in a workplace incident than non-users and off-duty users.
The study followed 2,745 Canadian workers in both safety-sensitive and non-safety-sensitive positions over a two-year period. The researchers analyzed the 11.3 percent of participants who experienced a workplace injury during that time. They found that among all respondents, 10.2 percent of those injured fell into the non-user category, 11.14 percent were classified as off-duty consumers, and 20.13 percent reported using marijuana either two hours before or during work.
According to the study, compared to workers who reported no past-year cannabis use, the risk of experiencing a workplace injury was 1.97 times higher among workers who reported workplace use. However, no statistically significant association was observed between non-workplace use and workplace injury. Therefore, the authors concluded that workplace cannabis use is a risk factor for workplace injuries, while non-workplace use does not pose an elevated risk.
When stratified for safety-sensitive workers, the rates of injury were even higher. For non-safety-sensitive jobs, 20.14 percent of non-users experienced injuries compared to 23.3 percent of off-duty users and 31.35 percent of on-the-job users. For safety-sensitive jobs, only 4.27 percent of non-users experienced injuries compared to 4.19 percent of off-duty users and 12.3 percent of on-the-job users.
The authors believe that their study provides greater clarity on the question of whether cannabis use increases the risk of workplace injuries. They argue that previous research has been limited because it failed to account for the timing of consumption in relation to workplace injuries. The study’s findings highlight the importance of considering when cannabis use takes place, emphasizing that only use in close temporal proximity to work appears to be a risk factor for workplace injuries.
The researchers also stated that their findings do not diminish employers’ legitimate concerns regarding workplace impairment. However, they suggest that zero-tolerance policies that prohibit cannabis use entirely, including outside of work, may be overly broad and incompatible with the results of this study. Instead, more nuanced approaches to workplace policies around cannabis use may be warranted. For example, employers could consider implementing minimum waiting periods after cannabis consumption when impairment is most likely present.
This study adds to a growing body of research on the effects of cannabis use in the workplace. A 2021 study published by the National Bureau of Economic Research found that legalizing marijuana for adult use is associated with an increase in workforce productivity and a decrease in workplace injuries. Similarly, a 2019 study showed that legalizing medical cannabis was linked to fewer workers’ compensation claims that were less costly on average.
In conclusion, this new study challenges traditional zero-tolerance employment policies regarding marijuana use off the clock. It suggests that workers who consume cannabis outside of work are no more likely to experience workplace injuries compared to non-users. However, it is important to note that indulging in marijuana during work hours significantly increases the risk of workplace incidents. Employers should consider adopting more nuanced policies around cannabis use and implement measures to address impairment during working hours while also respecting workers’ rights when they are off duty.
