September 15, 2018
The federal Cannabis Act, which legalizes the consumption of recreational cannabis across Canada will come into force Oct. 17, 2018.

Since Bill C-45 was passed by the Senate on June 19, 2018, employers have been scrambling to implement policies and prepare for the significant risks that come with the recreational use of marijuana.

Dr. Bruce Demers, Medical Director and Chief Medical Review Officer, CannAmm Occupational Testing Services, says, “It increases the risk of accidents and injuries, period.”

Research has shown marijuana affects critical areas of the brain, including those responsible for motor control. Those who use cannabis regularly may also have trouble with certain driving skills for weeks after their last use because THC (the active ingredient in marijuana) can affect coordination, reaction time, ability to pay attention, decision-making abilities, and ability to judge distances. For some, marijuana increases the risk of developing mental illnesses such as psychosis or schizophrenia, especially among those who use cannabis frequently.

Employers should also be aware of some general facts regarding marijuana:
  • Marijuana is much more potent than it was even a decade ago and there’s no consensus on a clear, safe limit.
  • Marijuana and alcohol affect the body differently and require separate approaches.
  • What people do on their own time matters. Marijuana affects critical cognitive functions in various ways and these impacts may linger for a significant period after use.
  • It’s easy to create a policy on your own. The difficulty lies in creating a policy that can withstand a legal challenge, and without a strong policy your company may be vulnerable.
  • The larger your workforce, the more likely that substance use will impact your workplace.
Under the Occupational Health and Safety Act (OHSA), impairment via medicinal or recreational marijuana carries the same workplace hazards and penalties as impairment via any other drug or alcohol.

The consumption of recreational cannabis is not allowed in workplaces, public places or motor vehicles, and a zero tolerance system is in place for commercial vehicle drivers, road-building machines (bulldozers, graders, etc.), and any vehicle that requires a Commercial Vehicle Operator’s Registration (CVOR).

Under the OHSA, employers, including supervisors, are legally obligated to take every reasonable precaution to ensure the health and safety of all workers on a project. An impaired worker is a danger to themselves and others around them and those responsible must take action to ensure the safety of all.

Employees also have a responsibility under the OHSA to report any hazards, including impairment to their supervisor or employer.
Workplace Safety and Prevention Services (WSPS) offers some tips to employers on dealing with this issue:
  • Implement a policy before Oct. 17.
  • Marijuana use, even on the employee’s own time, has lasting and long-term effects that adds potential danger to occupations in the green profession.
  • Draft a comprehensive, legally defensible policy that addresses medical marijuana and recreational marijuana use, as well as all other required content in a fitness for duty program.
Many resources are available, including a number of fall workshops presented by WSPS. For more information, visit or