Asleep on the job? Fatigue at work

Repetitive tasks, long hours, shift working, standing for long periods, working unsociable hours, problems at home, boredom — there are many reasons why employees may be fatigued at work but fatigued workers often mean an increased propensity for workplace accidents and increased human error. What can employers do to ensure their workers are alert and safe? Dr Lisa Bushby reports.

According to the Health and Safety Executive (HSE), fatigue is a perceived state of weariness caused by prolonged or intensive exertion. As it is estimated that up to 80% of accidents may be attributed, at least in part, to the actions or omissions of people, it is easy to see that fatigue that results in slower reactions, reduced ability to process information, memory lapses, absent-mindedness, decreased awareness, lack of attention, underestimation of risk, reduced co-ordination, etc can lead to errors and accidents, ill health and injury, and reduced productivity. Indeed, it is often a root cause of major accidents, see the various examples of the Herald of Free Enterprise, Chernobyl, Texas City, Clapham Junction, Challenger and Exxon Valdez.

In its publication, Reducing Error and Influencing Behaviour, the HSE gives an example of a small mistake by a chemist caused by a lapse in concentration that had big repercussions.

“Two similarly named chemicals were manufactured at a chemical works in batch reactions. Each required the presence of an inorganic base to maintain alkalinity to prevent exothermic side reactions. Development work was in progress which involved altering the various ratios of chemicals in each reaction. A chemist, in calculating the quantities of inorganic base required, inadvertently transposed the figures (a typical slip). As a result one reaction was carried out with only 70% of the required base present and an exothermic side reaction resulted. The subsequent explosion destroyed the plant. The system was not designed to cope with a runaway exothermic reaction. There was no system for checking the calculations.”


The very nature of analytical work or scientific experiments, for example, requires an element of repetition; indeed, techniques are designed to be reproducible.

Accordingly, for employees such as laboratory technicians and researchers, those on production lines or data inputters, an element of fatigue resulting from boredom or lack of attention may present itself. Managers can help prevent such decreased awareness by introducing frequent changes of task into the job.

A change of task every half an hour or so, such as cleaning machinery for 15 minutes, catching up on emails or switching tasks with a colleague can help ensure their usual work is carried out with increased attention to detail. For those whose job involves long periods at a display screen — a display screen equipment (DSE) assessment needs to be carried out and users should be encouraged to take short regular breaks to prevent eye fatigue. If possible, cross-train relevant employees so that they can be shifted to different positions occasionally. This will help to maintain interest in the job and increase morale with new skills.

Other suggestions are to allow music (or audiobooks, etc) in the workplace if it will not affect the concentration of employees, to allow chat between co-workers and to occasionally set different targets. Where possible, give as much control as possible to employees to organise their own work schedule and the timing of breaks.


Staff should be advised on how to prevent fatigue in the workplace.

One key element is a good night’s sleep. If anyone suffers from insomnia, good sleep hygiene is likely to help. Routine is key — establish fixed times for going to bed and getting up (most people require six to eight hours of sleep per night), turn off computers and devices well before sleep, avoid caffeine and use blackout curtains to create a dark sleeping environment if necessary.

Interspersing work with simple stretch exercises can help stimulate blood flow to the brain, eg shoulder lifts, neck stretches, pushing arms out in front, or pulling elbows back.

Hydration is also important — dehydration is a cause of tiredness and can also lead to headaches and poor concentration.

Ergonomic changes to the task and the working environment also help to reduce risks and can improve physical and mental wellbeing. For example, anti-fatigue mats are designed to reduce fatigue caused by standing for long periods on a hard surface.


Working long hours, working nights, getting up to work in the early hours of the morning, or simply having irregular hours of work disrupts the body’s routine and circadian rhythm, or body clock, and can lead to stress and tiredness. Along with serious health and safety problems that this introduces, it can also lead to lower productivity.

The EU’s 2014 Labour Force Survey showed that full-time employees in the UK worked on average the longest hours at 42.4 hours per week. However, while many people enjoy their jobs and are happy to work extra hours when there is business need or for a bit of extra cash, managers can ensure staff avoid long shifts and too much overtime. Often associated with preventing drivers falling asleep at the wheel after working long hours, the Working Time Regulations impose a limit of an average of 48 hours a week which a worker can be required to work (though workers can choose to work more if they want to).

Sometimes, work needs to be carried out longer than the traditional 9–5 hours of a working day and the employer must introduce a shift working system following consultation with staff. Indeed, recent Office for National Statistics figures for those over age 16 working shifts indicated about 17% of the workforce work shifts. Of these, 500,000 work night shifts.

According to the HSE, there is no one solution to the potential health and safety impact of fatigue and shift work. “Best practice” is a multi-component approach which includes:

  • careful planning of shift rostering taking into account knowledge of the effects of biological rhythms

  • reviewing maximum hours of duty and time for recovery

  • education of shift workers on sleep routines, nutrition, effects on family and social life, exercise

  • environmental design changes, especially those aspects which can improve alertness such as temperature, lighting and comfort levels

  • reducing the number of safety-critical tasks planned for the night shift

  • rotating jobs to reduce levels of boredom

  • providing medical advice for shift workers, especially for those with existing medical conditions.

It is worth noting that the Management of Health and Safety at Work Regulations 1999 state the obligations placed on employers to make suitable and sufficient assessments of risks to their employees. Risk assessments must take account of the provisions of the Working Time Regulations.

If a worker is required to work for more than six hours at a stretch, he or she is entitled to a rest break of 20 minutes. The break should be taken during the six-hour period and not at the beginning or end of it.

Finally, managers should look out for any increased incidence symptoms of fatigue among staff, which can include yawning, loss of concentration, depression and anxiety, dizziness, confusion, blurred vision and stress.