Cannabis impairment

Cannabis is not legal yet

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Impaired driving

Impaired driving is the leading cause of criminal death and injury in Canada.

Cannabis impaired driving can result in injury or death for you, your passengers and others. Cannabis:

  • impairs your judgement
  • affects your ability to react
  • increases your chances of being in a crash

Never get into a car with an impaired driver. It is not worth the risk.

Mixing cannabis with alcohol increases your level of impairment and leads to an even greater risk of an accident. Footnote 1


Law enforcement are trained to detect drug-impaired driving. They enforce drug-impaired driving laws using:

  • Standard Field Sobriety Testing (SFST)
    • typically administered at the roadside
  • Drug Recognition Expert (DRE) evaluation
    • includes a series of tests and a toxicological sample (urine or blood)
  • Oral fluid drug screening equipment
    • Law enforcement can demand a driver provide an oral fluid sample on approved oral fluid drug screening equipment
  • Blood samples
    • Law enforcement can demand a blood sample from a driver if they believe they have committed an offence

Law enforcement across Canada have SFST and DRE trained officers and the number of officers being trained is increasing. They also have training and access to approved oral fluid drug screening equipment.

Working together against impaired driving

We are working with provincial and territorial partners, as well as other groups such as:

Together we are working to raise awareness of the dangers of drug-impaired driving.

Our common goals are to:

  • make Canadians aware of the serious dangers of drug-impaired driving
  • make drug-impaired driving socially unacceptable in Canada
  • reduce the number of people driving impaired by cannabis or other drugs
  • make our roads and communities safer for all


You could face consequences like a fine, criminal charges or even jail time if you drive impaired by cannabis or other drugs. Learn more about how impaired driving laws are enforced in Canada.

How long cannabis impairment effects last

Cannabis impairment is different for every individual and can be influenced by how you take cannabis. For example, the effects will be felt longer if you eat or drink cannabis-based products. There is no standard waiting time to drive after using cannabis. If you are using cannabis, do not drive. Find an alternative:

  • stay over
  • call a taxi
  • share a ride
  • use public transit
  • have a designated driver

Public awareness

Check out the Don't Drive High website on the dangers of drug-impaired driving.

Workplace impairment

Someone who is impaired may have difficulty completing their work tasks safely and may put themselves, their coworkers and the public in danger.

There are many potential causes of impairment. In addition to factors such as fatigue and certain medical conditions, these include the use of legal and illegal substances such as:

  • alcohol
  • cannabis
  • street drugs
  • certain medications

A shared responsibility

Everyone has a role to play in workplace health and safety. Employers and employees alike should be prepared to prevent the risk of cannabis impairment at work and should note the following employer and employee responsibilities in federally regulated workplaces. For businesses or industries regulated by the province or territory, please refer to provincial and territorial governments.

Employers' responsibilities

Employers should:

  • ensure the health and safety of all employees at work
  • address physical and/or psychological hazards in their workplace, including when impaired.
  • work with employee representatives to develop, implement and evaluate a hazard prevention program to monitor and prevent hazards
  • include policies on substance use and impairment in a hazard prevention programs when the use of cannabis and other causes of impairment represents a hazard

Employees' duties

Employees must:

  • work safely
  • understand the impact that using substances (medical/therapeutic or non-medical) can have on their safety and that of others
  • report to their employer any thing or circumstance that is likely to be hazardous to the employees or any other person in the work place
  • inform their employer if a medical condition or treatment may cause impairment and impact their ability to perform their job safely
  • follow all instructions provided by the employer concerning the health and safety of employees
Footnote 1

Fischer B, Russell C, Sabioni P, van den Brink W, Le Foll B, Hall W, Rehm J, Room R. Lower-risk cannabis use guidelines: A comprehensive update of evidence and recommendations. Am J Public Health 2017 Aug;107(8):1277

Return to footnote 1 referrer