Canada: Long-Term Disability Series: Extended Work Hours, Shift Work And Personal Health

Last Updated: October 16 2017
Article by Renée Vinett

It's been said that "what we do during our working hours determines what we have; what we do in our leisure hours determines what we are." But what happens when our working hours have a detrimental effect on our leisure hours? What if the rigours and demands of long hours and shift work cause fatigue that significantly increases the chances of sustaining personal injury? In this blog post, I review the nature and effects of fatigue, sleep deprivation, extended work hours, and warning signs that an individual may be suffering from fatigue.

The Nature of Fatigue

Fatigue typically relates to the state of feeling physically and emotionally exhausted caused by prolonged work hours, physical or mental activity, insufficient rest, high levels of stress, or a combination of these. Fatigue is very much a personal and subjective experience. Some common physical symptoms include:

  • Feeling tired;
  • Drowsiness;
  • An inability to stay awake;
  • Dizziness and vertigo;
  • Appetite loss;
  • Irritability and anger; and,
  • Anxiety.

The Effects of Fatigue

These symptoms can be profound, impair an individual's ability to work, and create workplace hazards. Typical effects include:

  • Impaired judgment (pursuing an improper or unsafe course of action);
  • Compromised concentration and focus;
  • Decreased vigilance and awareness of potential danger;
  • Reduced memory and ability to recall proper process and procedure;
  • Increased risk-taking;
  • Slowed reaction time (physical and cognitive); and
  • Decreased motivation.

Sleep Deprivation

Current medical research suggests that an individual requires between 7.5 and 8.5 hours of sleep per day.i Although losing sleep in a single night may not significantly impact an individual's work performance and the sleep deficit can be made up the following day, prolonged sleep deprivation creates a "sleep debt" which cannot be supplemented by future sleeping periods. If sleep periods are shortened for weeks or months at a time, an individual will develop chronic sleep deprivation and job performance levels will suffer as a result.

However, even the loss of 1 hour of sleep per night over a continuous period can increase the likelihood of an individual falling asleep on the job and impair work performance. Such circumstances create attention lapses and low levels of alertness. Where an individual experiences severe sleep deprivation, they are susceptible to short periods of sleep called "micro sleeps". These micro sleeps do not alleviate fatigue and an individual continues to feel tired and performs poorly.

Recent employment studies show that individuals who work night shifts lose approximately 5-7 hours of sleep relative to their day-shift-working colleagues.ii While some of this sleep loss can be recouped during time off from work, it is symptomatic of a chronic state of partial sleep deprivation which impacts an individual's mood and work performance.

The most common causes of sleep deprivation include:

  • Environmental conditions (noise, light, temperature, poor sleeping surface, new surroundings);
  • Chemical or technological stimulants (caffeine, television, cell phone);
  • Prescription drugs;
  • Illness (sleep apnea, chronic obstructive pulmonary disease, emphysema); and
  • Alcohol (sleep may come quickly, but it is light, disturbed, and not rejuvenating).

Extended Work Hours

The term "extended work hours" means different things in different industries. For some business environments, extended work hours signify a 12-hour work day while in other markets it means that the work period ranges from 12 to 16 hours per day. An individual who works 12 to 16 hours per day will likely only have 4 to 5 hours to sleep if commute, eating, and socializing are taken into account. Extended work hours can therefore cause fatigue and, in turn, create potential workplace hazards.

High-Risk Periods

Where an individual must concentrate for a sustained period of time to ensure a safe working environment, research by workplace health and safety organizations shows that "the probability of an [accident] occurring rises and falls with the tendency to fall asleep."iii Not surprisingly, the highest rate of accidents typically occurs during night shift work. The most serious accidents are likely to occur when individuals are most susceptible to sleep: 12:00 a.m. – 6:00 a.m. and 1:00 p.m. – 3:00 p.m.

Employer Considerations

From an employer perspective, consideration must be given to workplace hazards when determining whether extended work hours are appropriate. Such hazards include chemical or biological agents, noise and vibration, and extreme temperatures. Employers must also be aware of the fatigue-inducing effects of certain types of personal protective equipment such as respirators and heavy safety clothing.

Peer Pressure

A workplace culture which values endurance to work long hours can lead to fatigue. Working through extreme fatigue is as counterproductive as it is dangerous. In workplace cultures such as this, an employer must impose mandatory "off-duty hours" to encourage individuals to rest and sleep.

Warning Signs

The only effective way to combat fatigue is by resting and sleeping. However, individuals who suffer long-term fatigue may adopt coping strategies which can serve as warning signs to fellow employees and an employer:

  • Reduced productivity as a result of slower work performance;
  • Increased and more thorough inspection of work product;
  • Selecting easier, less important, and more straightforward work tasks;
  • Seeking more assistance from colleagues; and
  • Increased reliance on reminders.

The reduction in work efficiency reflects an individual's attempt to accommodate a reduced functioning level due to fatigue. This strategy seeks to minimize errors that may cause personal injury or injury to co-workers. When such warning signs occur over an extended period of time, it is imperative that they be brought to the attention of management so that potential accidents may be avoided.

If you have suffered a personal injury as a result of workplace fatigue, you deserve support, care, and compensation.





The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

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