OHS Canada Magazine

Don’t snooze on safety: Fighting fatigue in the workplace

October 16, 2023
By Canadian Centre for Occupational Health and Safety (CCOHS)
Human Resources ccohs fatigue Fatigue and safety Sleep

A tired industry worker sleeping on metal construction. Photo: dusanpetkovic1/Adobe Stock

Feeling tired, foggy, mentally, or physically tired, or lacking motivation? These are all signs and symptoms of fatigue. Whether it’s due to working long hours, not getting enough sleep, or from long periods of stress or anxiety, workplace fatigue is a hazard employers should be concerned about.

The impact of fatigue can be considered a form of impairment, making it a workplace hazard that can be dangerous for not only the worker, but also for other employees and even members of the public. Consider delivery truck drivers, for example. If preventative measures aren’t put in place, long hours from shift work or extended workdays may result in the drivers feeling fatigued while on the road, putting themselves and others at risk.

Research has shown that the number of hours awake can impact the body in a similar way to blood alcohol levels. One study reported that 17 hours awake is equivalent to a blood alcohol content of 0.05, and 21 hours awake is equivalent to a blood alcohol content of 0.08 (the legal limit for drivers in Canada). Other studies have shown that workers who have slept for less than five hours before work, or have been awake for more than 16 hours, have a significantly higher chance of making mistakes at work because of fatigue.

While it can be difficult to isolate the effect of fatigue on incident and injury rate, recognizing it as a workplace hazard and implementing controls can help employers proactively prevent fatigue-related incidents.

Work and non-work-related causes

There are a number of factors that can contribute to fatigue at work. These factors may include long work hours or long hours of physical or mental activity, insufficient break time between shifts, or changes to jobs or shift rotations. Inadequate rest, excessive stress, and balancing multiple jobs are also contributing factors.


Feelings of fatigue can be increased by dim lighting, limited visual alertness due to weather, low light, or other factors, high temperatures, or noise. It also becomes an issue when tasks must be sustained for long periods of time, or where they are repetitive, paced, difficult, boring and monotonous, or non-strenuous.

Workers may be dealing with external contributing factors, such as a sleep disorder or prescription medication that affects the length or effectiveness of their sleep.

Some disorders such as insomnia, sleep apnea, restless legs syndrome or narcolepsy, can cause extended wakefulness or disruptions to circadian rhythms. Illness and other medical conditions can also affect sleep length and sleep quality.

Assess the risks

Take a thorough look at your workplace, and identify objects, situations and processes that have the potential to cause harm due to fatigue. Once you’ve identified fatigue as a hazard, you can evaluate how likely and severe the risks are, then decide how to effectively eliminate or control the harm. Note that the work environment should have appropriate lighting, temperature, and noise levels. Fatigue may be increased by long, repetitive, and monotonous tasks so it’s important to offer a variety of tasks throughout the workday.

If possible, optimize the design of the shift schedule by establishing the length of the rotation period and the direction of shift rotation. Create a schedule for shift workers that rotates forward, allowing them to go from a day shift to an afternoon or evening shift, and then into a night shift. This rotation is easier on the body and helps to build a routine.

If the job allows for it, try to adjust the work plan for the day. The most demanding and high-risk tasks should be avoided towards the end of the shift, or between certain hours (between the hours of midnight and 6 a.m.) when employees may be less alert.

Train workers

In addition to feeling very tired, weary, or sleepy, workers should also know how to recognize less obvious symptoms — reduced ability to be productive, lack of motivation, depression, headaches, and increased frequency of illness. Feelings such as giddiness, boredom, loss of appetite, and digestive issues may also be signs of fatigue.

Train everyone on the hazards of fatigue, including how to recognize symptoms such as weariness, sleepiness, irritability, being mentally or physically tired, and reduced alertness, concentration, and memory.

Promote healthy habits

Equip workers with the information they need to help address fatigue. Getting enough quality sleep is the habit sure to make the biggest impact. There is no one way to get good sleep – what works for one person may not work for another. General tips include going to bed and getting up at the same time every day; limiting screen time before sleep; exercising regularly; and using the bed primarily just for sleeping instead of activities like watching television. Not tired? Don’t force it. Do something quiet instead, like reading a book.

It may also help workers to establish eating habits that help encourage sleep and feeling good.

Having meals at regular times is important to function at our best. Skipping meals or eating at irregular times can contribute to fatigue, food cravings, or increased eating at the next meal. When working night shifts, it’s good to have a “main meal” before going to work. A heavy meal during the night may cause heartburn, gas or constipation, or make workers sleepy or sluggish.

Eating snacks between meals is a great way to stay nourished and get through work shifts with some energy. At breaks, opt for healthy snacks that include combinations of a variety of foods from the four food groups. Consider caffeine intake as well. Excessive caffeine can cause insomnia, headaches, irritability and nervousness. It is recommended that foods containing caffeine should not be consumed up to eight hours before sleeping.

Social considerations for shift workers

The amount and quality of social interactions people have are related to their physical and mental health. Individuals like shift workers, who cannot establish regular routines in their daily activities, have more difficulty planning for family responsibilities and participating in clubs, sports and other social activities. The shiftwork makes it harder for them to cope with physical and mental fatigue than non-shift workers.

The lack of regular social contact can lead to feelings of loneliness and isolation. Since recreational opportunities are often minimal for workers on non-day or night shifts, some organizations offer facilities for social activities with the needs of shift workers in mind.

Providing access to quality childcare for shift workers’ children can also help ease strain on their families.

Create a culture of support

Encourage employees to speak up if they’re experiencing any symptoms of fatigue that may affect their ability to do their jobs safely. Workplaces can also provide mental health services such as employee assistance programs and promote healthy lifestyle campaigns that encourage healthier eating and drinking habits, and physical activity.

Fatigue can include mental, physical, or subjective states, and can cause workers to potentially be inattentive, physically exhausted, or drowsy. By following these tips and addressing potential hazards and associated risks, employers can be assured knowing that they’re helping workers to stay alert and stay safe while on the job.

The Canadian Centre for Occupational Health and Safety (CCOHS) promotes the total well-being — physical, psychosocial, and mental health — of workers in Canada by providing information, advice, education, and management systems and solutions that support the prevention of injury and illness. Visit www.ccohs.ca for more safety tips.


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