Substance Abuse in the Workplace – Policies and Procedures

What is Substance Abuse?

Substance abuse is defined as an overindulgence or dependence on an addictive substance. Typically, substance abuse refers to inappropriate use of alcohol or prescription and non-prescription drugs. Those with a dependence on substances have a lost sense of control of the situation. Often times, the dependence is severe enough that individuals abuse substances in the workplace. In these instances, it’s important for employers to be able to recognize the signs of substance abuse to be able to prevent it from occurring in the workplace, as well as ensure the safety, health and well-being of their employees. Furthermore, employers need to know the policies and procedures regarding substance abuse in the workplace. Employers should know how and when to intervene when an employee is abusing substances at work.


Energy Safety Canada and Construction Safety Association of Alberta have released a new version of the Canadian Model.  This Canadian Model provides employers with a standard approach to set policy and procedures around substance use in the workplace.

The Canadian Model for Providing a Safe Workplace (Canadian Model) Version 6.0 provides a common approach for construction, oil and gas industries. It outlines minimum expectations for a safe workplace, while recognizing that some companies may require higher or alternative standards based on the specific nature of their operations. Because it is a framework, some companies may use the model as-is, while others may modify and adapt some clauses to better fit their needs.

The Canadian Model is focused on protecting workers and the public against safety risk, respecting the dignity and privacy of the workers and assisting individuals who are afflicted by substance abuse disorders.

OHRC Drug and Alcohol Testing Policy 2016

The Ontario Human Rights Commission provided a new policy in 2016 to address an employer’s approach to drug and alcohol testing.  Over the past few years several legal decisions have reinforced the ability to control substances and perform testing in safety sensitive positions.  It is important to define the role in detail and the reason for designation of safety sensitivity.

The Toronto Transit Commission’s Drug and Alcohol Testing Policy was challenged but through the arbitration process it was found to be valid as a reasonable policy and procedure for Transit Operators.  The key parts of the program discussed the determination of a safety sensitive position and the actions that would be taken upon suspicion of use.

With the legalization of Cannabis approaching at the end of this year, it is important that each employer has a policy in place for:

  1. Zero tolerance of use at the workplace
  2. Determination of suspicion of use of substances
  3. Testing for safety sensitive positions
  4. Actions to support accommodation of employees with addictions

Medical Cannabis in the Workplace

A recent arbitration decision in Newfoundland brought to light further issues regarding the use of medical cannabis in the workplace. In April 2018, a grievor claimed an employer refused to accommodate his disability when he was not hired for certain labour positions within the company based on the use of his medically-authorized marijuana use. The employer’s defense involved the safety-sensitivity of the labour positions in question, and the concern of maintaining workplace safety given the grievor’s medical cannabis use. The grievor used his prescribed cannabis in the evenings to assist with pain and comfortable sleeping; he expressed the effects of the cannabis were gone by the morning. In the end, the arbitrator ruled in favour of the employer due to the following reasons:

  1. The exact length of cognitive impairment cannot be guaranteed due to a multitude of factors;
  2. Cannabis users may truly believe the effects have worn off long after consumption, however a lack of awareness may cause them to not recognize their functional impairment is still present, even if only slightly;
  3. A general practicing physician is not in a position to determine the abilities of a cannabis user in relation to a specific workplace, and;
  4. The lack of readily available testing resources to determine exact impairment from regular or one-time cannabis usage.

These factors contributed to the decision that the grievor would cause an increased safety risk, which would amount to undue hardship for the employer. This case sets a precedent and spreads awareness, as marijuana has become legalized in Canada, that frequent cannabis users may create safety concerns in the workplace. Read the full article here.

What do you need to know as an employer?

If you are working to develop a structured policy and procedure around substance use, testing and support of individuals with substance abuse concerns:

  1. Review the Canadian Model for application in your industry
  2. Adjust the standard to customize to your specific workplace, provincial regulations and business concerns
  3. Consider accommodations in your workplace for individuals with a disability such as, substance abuse (addiction).
  4. Contact an Occupational Therapist to assess the cognitive demands of the job role and the employee’s cognitive capabilities to find suitable work adjustments and tools to improve work performance and to determine fitness to work.

If you are interested in more information consider our webinars on Marijuana in the Workplace, Accommodation in the Workplace and OHRC Policy Changes.

Work Cited

Harnden, Emond. (2018). Arbitrator states worker’s use of medical cannabis results in “unacceptable increased safety risk” – grievance dismissed. Labour & Employment Law. Retrieved from


OHRC Policy on Drug and Alcohol Testing 2016 retrieved from:

Gowan N (2016) Human Resources Guide to Managing Disability in the Workplace, Carswell, Toronto.


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