This article was originally posted by Justin Ralph on

Extended work hours are becoming more and more frequent in Alberta, especially in the oil and gas industry. While there is some confliction between the hours that qualify work as an extended shift the “norm” is 12 hours or more. Generally, workers on extended workdays work fewer than 5 days a week, but let’s get real here, we work in Alberta and, more often than not, workers will accept more shifts, so they can rake in that overtime cash.

Listed below are some of the advantages and disadvantages of extended workdays that can be applied to all industries:


  • More days off, which will allow employees to spend more time with their families. Employees generally show a greater level of job satisfaction with the extra full day off
  • More rest to recover from fatigue
  • Less frequent commute. This helps the environment, and lets employees save money on gas
  • With twelve hour shifts, there will be noticeable increases in productivity due to less shift changes


  • Productivity may be negatively affected by fatigue due to long hours. Studies have shown that workers on twelve hour shifts are more prone to make errors as a result of fatigue
  • It may be more difficult to locate employees to replace certain shifts. In a typical work week, employees from the prior shift are generally asked to stay and work longer. Seeing as now employees work 12 hour shifts, it is not advised to ask employees to work extra time
  • Workers may show a decline in work pace, safety and alertness, causing workers to require more breaks throughout the shift

As defined by Alberta Workplace Health and Safety “Fatigue is a state of being tired. It can be caused by long hours of work, long hours of physical or mental activity, inadequate rest, excessive stress and combinations of these factors.” Fatigue is your body’s way of telling you that you need to get some rest. Fatigue can be a result of work-related factors and non-work-related factors. Studies show that working 17 hours impairs performance to the same level as having a blood alcohol level of 0.05.

Identifying fatigue as a hazard is an important step in any company’s hazard identification and control system. Factors that should be evaluated when determining fatigue as a hazard are the mental and physical demands of the work; are employees concentrating on one job for extended periods of time or performing work that requires continued physical effort. Work scheduling and planning; do the work shifts allow workers enough time to physically recover from the previous shifts work. Working time; are workers required to work during times when their biological clock is programmed to sleep. Environmental conditions; are the workers required to work in harsh or uncomfortable conditions i.e. excessive heat/cold/vibration. Factors outside of work; do employees have any lifestyle, home environment or health conditions that could affect their susceptibility to fatigue on an extended work shift i.e. children, multiple jobs, insomnia, drug or alcohol dependency etc.

Assessing fatigue risks is a way of deciding which hazards need to be addressed in which order and should reveal where, which and how many workers are likely to be affected by fatigue and the degree of harm that could result. Methods of fatigue risk assessment can include consulting with workers on workloads and schedules; inquire to whether they are having or have experienced work related fatigue. Reviewing workplace incident data and determine the likelihood of fatigue contributing to these incidents. Consulting with industry or employee associations who may be able to assist with risk assessments and checking whether employees have had incidents travelling home or on non work related journeys.

Controlling fatigue in the workplace can be achieved a number of ways. When selecting which methods to implement, ensure that the most effective methods are used. The best method is to eliminate the factors that cause fatigue, but as we live and work in a world where that is not always possible, choose the methods that best reduce the risk of fatigue. Mental and physical demands of work can be reduced by introducing job-rotation and using rest periods. Work scheduling and planning should incorporate adequate rest periods to ensure workers have adequate recovery time between shifts. Complex and safety-critical tasks should be scheduled during hours when the risk may be lower. These tasks are best undertaken during normal day shifts when workers are less likely to be fatigued. When planning work in harsh conditions, ensure workers have rest periods and are provided with shelter and beverages to keep their body temperatures normal. Lastly, when providing training and information to employees to help prevent work-related fatigue incidents, training should include items such as the body clock and how fatigue can affect it, risk factors and symptoms of fatigue, effective control measures and procedures for preventing and managing fatigue in the workplace, balancing work and life demands and personal health and wellness on and off the job.

Fatigue does not discriminate and can affect all employees, leading to tiredness, irritability, health problems, increased work errors and safety concerns among others. It is important for all levels of employees at the workplace to be trained in recognizing and managing fatigue in the workplace for the health and safety of themselves and others. Proper identification, assessment and control of fatigue affecting workers on extended shifts can lead to better health and safety outcomes, fewer workplace incidents and injuries, reduction in absenteeism and staff turnover, and better performance and productivity.