Safety Basics · Lesson 14 of 14

Mental health and substance use

Stress, fatigue, impairment and where to get help.

Please read: this free course is general education only. It is not a certification, it does not replace your employer's site-specific training, and it does not give you Working at Heights, WHMIS, First Aid or any other ticket — see the safety tickets guide.

Updated: Oct 2026.

Mental health is part of health and safety. Stress, fatigue and impairment affect your judgment and reaction time, and they can put you and your crew at risk.

Fitness for work

Impairment can come from alcohol, cannabis, opioids, some prescription or over-the-counter medications and other substances, but also from things like fatigue, stress or illness. On a jobsite, impairment can lead to serious injuries.

  • Come to work fit to do the job safely.
  • Follow your employer's policy on alcohol, cannabis and other drugs. Some prescription medications can cause drowsiness or slowed reflexes too.
  • If you think a co-worker is impaired and at risk, tell your supervisor. It's not the employer's or supervisor's role to diagnose anyone; their role is to identify impairment and act under the workplace policy.

Looking after your mental health

  • Work factors such as high stress, long hours, irregular shifts, fatigue and isolation can play a part in substance use problems.
  • If your employer has an Employee Assistance Program (EAP), it can help you directly or refer you to community services.
  • Substance use disorder is a medical condition, not a choice or a moral failing, and human rights laws treat it as a disability.
If you or someone you know is thinking about suicide, call or text 9-8-8, 24 hours a day, every day of the year. If someone's life is in immediate danger, call 9-1-1.

Key takeaways

  • Impairment can come from substances, fatigue, stress or illness.
  • Come to work fit for duty and follow your employer's policy.
  • An EAP, if your employer has one, can help or refer you.
  • Call or text 9-8-8 any time if you're thinking about suicide.

Check yourself

A quick self-check. Your answers stay in your browser: nothing is saved or sent anywhere, and it isn't a test for a certificate.

1. Which of these can cause impairment at work?
2. You think a co-worker is impaired and about to run equipment. What should you do?
3. What number can you call or text 24/7 in Canada if you're thinking about suicide?

Sources

  1. CCOHS — Workplace health and well-being (opens in a new tab)
  2. CCOHS — Substance use in the workplace (opens in a new tab)
  3. 9-8-8: Suicide Crisis Helpline (opens in a new tab)