Skip to main content
This website uses cookies. By continuing to use this website you are agreeing to our use of cookies as described in our privacy policy.

Determining Impairment in the Workplace

Reading Time 4 minute read

"Do" Diligence: OHS/WSIB Newsletter

The federal government's legalization of recreational cannabis on October 17, 2018 has brought forward the issue of workplace impairment.

We often think of impairment as a result of substance use or experiencing the effects of substance use from drugs or alcohol. The Canadian Human Rights Commission describes the appearance of impairment at work as: "odour of alcohol or drugs, glassy or red eyes, unsteady gait, slurring, poor coordination."[1] Being distracted or making inappropriate decisions while at work may also be considered a form of impairment. A person may be impaired for reasons other than drug or alcohol use, including from use of medications or extreme fatigue. For these reasons, it is important that determining impairment in the workplace be done on a case by case basis.    

Employers should develop a clear statement of what is considered to be impaired behaviour within their workplace. The following is a list of signs and symptoms that can be used to help determine impairment in general. They should simply be used as indicators that an employee may be in need of help regardless if the issue stems from substance use or another cause.

Indicators of Substance Use


Sweating, headaches, tremors, cramps, restlessness, odour of alcohol, slurred speech, unsteady gait, glassy eyes


Confusion, memory lapses, inappropriate responses/behaviours, lack of focus/concentration

Workplace Performance

Forgetfulness, deterioration in performance

Source: Impairment at Work - CCOHS

If impairment is suspected, employers should consider if there is a risk to the individual's safety or the safety of others. For example, while impaired:

Does the person have the ability to perform the job or task safely (e.g., driving, operating machinery, use of dangerous materials)?

Is there an impact on cognitive ability or judgement?

As with any occupational health and safety hazard, workers and supervisors should receive education and training to be aware of the signs and symptoms of impairment in the workplace and to take action if workplace impairment is known or suspected. Workers should be instructed to report incidents to their Supervisor immediately. If a Supervisor becomes aware of a worker who is showing signs of impairment it is important that immediate action is taken such as:

Speaking to the employee in a private area to discuss their behaviour (be respectful and ensure confidentiality);

Asking another person (manager) to be present as a witness;

Stating concerns about safety to the employee, asking them to explain what is going on and discussing options, as appropriate.

In some cases, such as when the employee's behaviour puts their own or someone else's safety at risk, it may be necessary to assign non-safety sensitive work, to ask the employee to stop their work or to have the employee escorted home. Employers should never allow an employee suspected of impairment to drive themselves. Supervisors should be familiar with their organization's available resources and supports, such as Employee Assistance Programs and help employees seek treatment as necessary.

Every discussion should be documented and include but not be limited to the following information:

  • the events that happened before the incident;
  • identification of the employee's unsafe work practices or acts;
  • the matters discussed with the employee (while maintaining confidentiality);
  • that management and union representatives were notified if applicable; and
  • a description of all actions taken.

The Canadian Centre for Occupational Health and Safety ("CCOHS") has recently released an Incident Report template[2] for documenting suspected impairment, which can be customized to suit workplace needs.

Proactively considering and addressing the issue of workplace impairment is important not only to ensure a safe workplace but also because the Ministry of Labour ("MOL") expects employers to take action. In its online publication "Impairment and Workplace Health and Safety", the MOL states that "workers performing work when they are unable or unfit to do so safely may introduce a hazard to the workplace, to themselves or to others, and workplace parties are required to address such hazards under the OHSA." Employers and supervisors have a general duty under OHS legislation to take reasonable precautions for the protection of workers in the workplace. When it comes to workplace impairment, employers should consider doing the following to ensure workers attend and remain at work fit for duty:

  • hazard assessment to identify, assess and control potential risks related to workplace impairment;
  • implementation of a Fit for Duty Policy; and
  • worker and supervisor training, including information and instruction on addressing workplace impairment.

If you have any questions on the legalization of cannabis for recreational use and its impacts on the workplace, or would like assistance in developing a Fit for Duty Policy or conducting training, please contact Cathy Chandler or Norm Keith.


[1] Impaired at Work - A Guide to Accommodating Substance Dependence, Canadian Human Rights Commission

[2] CCOHS Fact Sheet "Impairment at Work – Reporting and Responding".


    Receive email updates from our team