Safety Swap: Cannabis

Safety Swap: Cannabis

​​​​​​​​​​​Legalization of recreational use of cannabis came to force in October 2018. With legalization came questions for workers, health and safety committees and employers. Safety Swap

This Safety Swap provides information on:

  • Cannabis
  • Impairment
  • Workplace Questions

​​​​Questions that could be used to spa​​rk discussion 

What are some signs an​d symptoms exhibited by someone who has used cannabis? 

​Signs and symptoms may vary depending on the composition of the cannabis and the individual's tolerance. For example, the concentration of Tetrahydrocannabinol (THC) and Cannabidiol (CBD) in cannabis will impact how a person behaves after consumption. THC produces psychoactive symptoms while CBD is used for pain control. Different ratios and concentrations of these two substances will produce different signs and symptoms in users. 

According to Health Canada, the effects of cannabis on the body can include the following: 

  • dizziness 
  • drowsiness/fatigue 
  • headache 
  • impaired memory 
  • disturbances in attention, concentration and ability to think and make decisions​
  • disorientation, confusion 
  • changes in motor skills and perceptions. 

What can impact the length of time someone might be impaired? 

The effects of using cannabis can differ from person to person. The amount of THC content and/or CBD content are factors to consider. The route of consumption will also impact the duration of impairment. For example, if cannabis is ingested orally, impairment is likely to last longer than if cannabis is inhaled. 

What does the legalization of cannabis mea​​​​​​n for my workplace? 

Employers have a responsibility to ensure a safe workplace, as set out by Part 4 of The Workplace Safety and Health Act in Manitoba. Developing and following a policy to address workplace impairment will help to demonstrate due diligence on the part of the employer. 

​​Workers are required to be at work with the ability to perform the duties of their job and this has not changed since the legalization of cannabis. However, there may be situations where a worker requires accommodation if cannabis is being used for medical purposes. In these instances, accommodations of the individual's disability need to be made up to the point of undue hardship, which is a requirement under Human Rights Legislation. 

What causes i​​​​​​mpairment? 

Impairment may refer to any state in which an individual's level of function is diminished. It can be caused by the consumption of alcohol, and legal or illegal drugs. It may also be caused by fatigue or medical conditions, for example. ​

A person may appear to be impaired if they exhibit slurred speech, poor coordination, unsteady gait, red or glassy eyes or an odour of alcohol or drugs. Employers and supervisors should not make assumptions about causes of impairment and should talk to workers they believe may be impaired to investigate the situation further. It is appropriate to ask the worker what is going on, however, employers do not have the right to ask for or access workers’ personal health information. 

Sources: Canadian Centre for Occupational Health and Safety (CCOHS); Canadian Human Rights Commission 

Why is my role as a committee mem​​ber when it comes to cannabis and impairment in the workplace? 

The role of the committee member is to help the employer raise awareness of the topic, however, the committee does not enforce a drug and alcohol policy in the workplace. It is the role of the supervisor or management to enforce the policy. 

Top Ti​​ps: 

  1. Seek legal advice. 

  2. Ensure there is a Drug and Alcohol policy at your workplace. Samples can be found at, however your employers must ensure that your policy is unique to your workplace. 

  3. Understand that there are several signs and symptoms that can be experienced depending​ on the composition of the cannabis and the individual's tolerance. 

  4. Understand the signs of impairment and the potential causes. 

Additional Resources and R​eferences 

Some additional resources on cannabis and impairment in the workplace include: 

For more information about cannabis and impairment in the workplace, consider taking our free e-learning course​.​ 

Share your ideas! 

​​If you would like to share your best practices with other safety and health committee leaders, we’d like to hear from you. Your idea might be featured in an upcoming issue of Safety Swap! Email us: for more information For more information Visit or call 204-957-SAFE (7233) or toll-free 1-855-957-SAFE (7233). ​

​Note: All staff in your workplace should be trained to call 911 immediately and follow the 911 operator's instructions if they encounter a person who requires medical attention related to a medical condition or use of medications (for medical purposes or illicit). Please see the additional resources list below for more information. 

The information contained in this resource is not legal advice and should not be relied on as such​.

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