Work performance

High levels of fatigue cause reduced performance and productivity, and increases the risk of accidents and injuries. Fatigue affects the ability to think clearly. As a result people who are fatigued are unable to gauge their own level of impairment, and are unaware that they are not functioning as well or as safely as they would be if they were not fatigued.

Performance levels drop as work periods become longer and sleep loss increases. Staying awake for 17 hours has the same effect on performance as having a blood alcohol content of 0.05%. Staying awake for 21 hours is equivalent to a blood alcohol content of 0.1%.

The most common effects associated with fatigue are:

Desire to sleep;
Lack of concentration;
Impaired recollection of timing and events;
Irritability;
Poor judgement;
Reduced capacity for communicating with others;
Reduced hand-eye coordination;
Reduced visual perception;
Reduced vigilance;
Reduced capacity to judge risk; and
Slower reaction times.

Not only do these effects decrease performance and productivity within the workplace, but they simultaneously increase the potential for incidents and injuries to occur. People working in a fatigued state may place themselves and others at risk, most particularly:

When operating machinery (including driving vehicles);
When performing critical tasks that require a high level of concentration; and
Where the consequence of error is serious.