Many aspects of the workplace require alertness, accuracy, and quick reflexes. An impairment to these qualities can cause incidents, and interfere with the accuracy and efficiency of work.

Impairment may be the result of many situations (including fatigue or stress). Situations where problematic substance use may result in issues at work include:

• any impact on a person's judgment, alertness, perception, motor coordination or emotional state that also impacts working safely or safety-sensitive decisions,
• after-effects of substance use (hangover, withdrawal) affecting job performance,
• illness or injury,
• absenteeism, or reduced productivity,
• preoccupation with obtaining and using substances while at work, interfering with attention and concentration,
• illegal activities at work, including selling illicit drugs to other employees, and
• psychological or stress-related effects due to substance use by a family member, friend or co-worker that affects another person's job performance.

Note that substance use is often thought of as an addiction or dependence, but use can be anywhere on the spectrum or scale from recreational to frequent to problematic. As a result, there are varying impacts on lives and work. A person may use a substance casually for years with no progress to harmful use, may be at different points of the spectrum at different times, etc.

Because of this spectrum, 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 sharp objects)?
• Is there an impact on cognitive ability or judgement?

Remember - In a workplace, it is not the employer’s role to diagnose a person as having a substance use disorder, but to be aware of signs that use may be an issue.

This document discusses issues such as how problematic substance use may affect the workplace, and possible costs to an organization.

The following table is a general summary of common substances and their effects.  
Note if the substance is used by injection, the sharing of needles may spread Hepatitis B, or C and HIV.

(Source: Health Canada “Controlled and illegal drugs” (various documents dated 2020 to 2022))

Sometimes, regular use of substances can change our brain function and structure so that there is no control over the need to use substances, regardless of the possibility of harm. These changes to our brain function may result in a health condition called substance use disorder.

Substance use disorder is a medically diagnosed condition, not a choice, weakness, or moral failing. The risk of substance use disorder and how fast a person becomes addicted varies by substance.  Some substances, such as opioid painkillers, have a higher risk and cause the disorder more quickly than others.

Substance use (addiction) is not a choice.  When a person is affected by substance use disorder, they crave the drug and are not concerned about its harmful effects. The drug becomes the focus of their feelings, thoughts, and activities.

Substance use disorder is actually very complex, and people develop the disorder for many reasons, including:

• events in life, especially trauma or chronic stress
• environmental factors
• mental well-being (emotions, thoughts, feelings, mental illness, etc.)
• genetics and biology

These reasons and physical dependence make it hard to stop using substances.

Substance use disorder is a treatable medical condition. No one chooses to become addicted. Do not think it is a simple matter of a person not having the willpower to control themselves.

Understand that when an individual seeks help or treatment, this journey may have many routes, and healing may take some time. Recurrence is common.

The economic impacts of substance use in Canada on a workplace or industry have been traditionally difficult to measure. Many costs are hidden by general absenteeism or illnesses, "unnoticed" lack of productivity, or inability or reluctance to link substance use directly with causes of incidents.

Costs to a business may be both direct and indirect. The impacts of substance use that have been reported include:

• safety (fatalities, incidents, etc.),
• absenteeism/sick leave/turnover or presenteeism,
• loss of production, and
• workplace violence and harassment.

Additional costs can include:

• tardiness or sleeping on the job,
• theft (e.g., money, items taken for resale),
• poor decision-making,
• loss of efficiency,
• lower morale and physical well-being of the worker and co-workers,
• increased likelihood of having trouble with co-workers or supervisors,
• disciplinary procedures,
• drug testing programs,
• medical/rehabilitation/employee assistance programs, and
• training of new employees.

Various and numerous organizational, personal and social factors can play a major role in why a person may choose to use a substance. In general, however, some work-related factors can include:

• high stress,
• high demand/low control situations,
• low job satisfaction,
• long hours or irregular shifts,
• fatigue,
• repetitious duties,
• periods of inactivity or boredom,
• isolation,
• lack of opportunity for promotion,
• lack of, remote, or irregular supervision, and
• easy access to substances.

The workplace can be an important place to help address substance use issues. Employers and employees can collaborate to design a management of impairment policy that outlines what is an acceptable code of behaviour and what is not.

The main goal is that workplaces are encouraged to establish a procedure or policy so that help can be provided in a professional and consistent manner. It is important for supervisors and managers to have a resource or procedure that they can rely on if the need arises. Employees need to know that everyone will be treated the same way. These actions help to reduce the stigma associated with substance use. When stigma is reduced, it is hoped that people will seek help without fear, and will speak openly about substance use issues. Early treatment and support are encouraged.

In addition, managers and supervisors should be educated in how to recognize and manage substance use issues, and employees should be offered educational programs. Recall it is not the role of the supervisor or employer to diagnose a possible substance use or dependency problem. Their role is to identify if an employee is impaired and to take the appropriate steps as per the organization’s policy.

By establishing or promoting programs such as an Employee Assistance Program (EAP), employers can help employees more directly or provide referrals to community services.

Note that under federal, provincial, and territorial human rights legislation, substance use disorder is considered a disability.  Discrimination based on disability is not legal.  Employers have a duty to accommodate disabilities to the point of undue hardship. Undue hardship is considered on a case-by-case basis. 

Please see the OSH Answers Impairment at Work – Policy and Recognition for details to be included in a management of impairment in the workplace policy.