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Medical Marijuana

What is marijuana (marihuana/cannabis)?

Marijuana (also called weed, pot, grass and many other terms) is a tobacco-like greenish or brownish material consisting of the dried flowering, fruiting tops and leaves of the cannabis plant, Cannabis sativa, the hemp plant.

What, in general, are the health effects from using marijuana?

When smoking marijuana the chemicals in the plant pass from the lungs into the blood vessels, which carry them throughout the body and to the brain. The immediate effects include euphoria and relaxation, changes in perception, time distortion, deficits in attention span and momentary body tremors, and impaired motor functioning. As Health Canada states “Using cannabis or any cannabis product can impair your concentration, your ability to think and make decisions, and your reaction time and coordination. This can affect your motor skills, including your ability to drive. It can also increase anxiety and cause panic attacks, and in some cases cause paranoia and hallucinations.”

These effects are delayed if marijuana is ingested, because the chemicals must first pass through the digestive system.

Users can have varying sensitivity to the effects of marijuana.

What are issues an employer should consider if marijuana is used for medical purposes?

In Canada, commercial production and distribution of marijuana for medical purposes is regulated under the Federal regulation - Access to Cannabis for Medical Purposes Regulations (SOR/2016-230).

As with the side effects from any prescribed or over-the-counter medication, employers should consider if there is a risk to the individual’s safety or the safety of others. For example, while under the influence of the medication:

  • Does the person have the ability to perform the job or task safely (e.g., driving, operating machinery, use of sharp objects)?
  • Is there an impact on cognitive ability or judgement?
  • Are there other side effects of the medical condition or the treatment that need to be considered?

Because users can have varying sensitivity, each individual should be assessed on a case-by-case basis.

What should employees and employers do?

While it is not appropriate for the employer to ask for specific medical findings and diagnoses from the employee or their health professional, employees may wish to consider informing their employer if a medical procedure or treatment may impact their ability to perform their job safely. If the organization has a substance use/abuse policy, it may be necessary to disclose the use of marijuana for medical purposes.

Employers should review any workplace policies involving drug and alcohol use, in consultation with the health and safety committee and unions, as appropriate. The focus of the policy should be on “impairment” or “under the influence”, and the ability to do the work safely. Policies should be inclusive and consider any prescribed drug or substance that is used medically (or otherwise).

Note, however, that the use medical marijuana does not entitle an employee to be impaired at work, nor can the use of medical marijuana allow that employee to endanger their own safety or the safety of others.

Do employers have a duty to accommodate?

Yes. Employees can ask for accommodations due to their medical condition. For workplaces, the duty to accommodate is required by federal and provincial human rights legislation, and this right includes those who may use medical marijuana as part of their treatment for a condition. Employers have this duty to accommodate, up to the point of “undue hardship”.

The employee should be evaluated using “fit to work” procedures where the purpose is to determine if medically the employee can perform the job or task under the working conditions. Please see the “Fit to Work” OSH Answers document for more information.

Typically, the employee will visit a medical professional who will determine if the person is able to do that particular job. The medical professional may consider physical or mental abilities, sensory acuity, level of skill, functional limitations, etc. The medical professional will typically only report one of three conditions back to the employer:

  • fit,
  • unfit, or
  • fit subject to work modifications.

Employers are provided with the information needed to determine appropriate work, and can confirm the nature and duration of the work restrictions with the medical professional.

Document last updated on September 6, 2016

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Although every effort is made to ensure the accuracy, currency and completeness of the information, CCOHS does not guarantee, warrant, represent or undertake that the information provided is correct, accurate or current. CCOHS is not liable for any loss, claim, or demand arising directly or indirectly from any use or reliance upon the information.