As fatigue is not easily measurable, it is difficult to determine the statistical impact of fatigue on workplace accidents. Research has shown however that when people sleep for less than five hours or when they have been awake more than 16 hours, the chance of making mistakes at work increases. 

WorksafeBC reported that 17 hours awake is equivalent to a blood alcohol level of 0.05, 21 hours awake is equivalent to 0.08 and 24 to 25 hours awake is equivalent 0.10.

On average, studies say that people need between 7.5 and 8.5 hours of sleep each night. Most night shift workers only get 5 to 7 hours of sleep.

The workers at highest risk of fatigue include shift workers, night workers, FIFO workers, drive in drive out (DIDO) workers, seasonal workers, on-call and call-back workers, emergency service workers and medical professionals and other health workers.

Most accidents tend to occur when people are likely to want sleep – between midnight and 6am. Sleep deficit has been linked to major disasters such as Chernobyl and the Exxon Valdez Oil Spill.

The common signs of fatigue are:

• Tiredness
• Irritability
• Depression
• Sleepiness (including falling asleep against your will)
• Digestive problems
• Giddiness
• Increased susceptibility to illness

In the workplace, fatigue can lead to:

• Reduced decision making ability
• Reduction in communication skills
• Reduced reaction time
• Loss of memory or recall
• Risk-taking
• Errors in judgement
• Increased accident rates
• Increased absenteeism
• Reduced ability to handle stress
• Reduced productivity
• Reduced attention span
• Headaches
• Impaired visual perception
•  

Workplace fatigue can also have consequences after work, including road accidents or impacts on personal life.

What causes fatigue?

Workplace factors relating to fatigue might include long work hours, long hours of high physical or mental activity, inadequate rest breaks, excessive stress, long commuting times or a combination of these factors.

Disruption of the body clock could occur as a result of shift work variations or through travelling to different time zones.

Insomnia sufferers are unable to fall asleep or stay asleep, and as a result they don’t feel rested and ready for the following day. It may be a short or long term condition. Short term insomnia is often the result of a stressful event or a change in environment.

Sleep Apnoea is a breathing disorder where there are brief interruptions in breathing during sleep. These generally last up to ten seconds. The frequent interruptions tend to result in a disturbed sleep and tiredness the following day.

Narcolepsy is a condition in which people suffer from ‘sleep attacks’. They have the uncontrollable urge to sleep many times each day.

Restless Leg Syndrome is when people have the irresistible urge to move their legs when trying to fall asleep, making sleep difficult to achieve. Movements may also occur while sleeping resulting in disrupted sleeping patterns.

Longer term health issues resulting from fatigue include:

• Heart disease
• Diabetes
• High blood pressure
• Gastrointestinal disorders
• Lower fertility
• Anxiety
• Depression

What can be done about it?

People suffering from fatigue can consider:

• Reducing nicotine intake
• Reducing caffeine intake
• Reducing alcohol intake
• Accessing medical advice for the condition
• Going to bed and get up at the same time each day
• Engaging in regular exercise
• Consuming a healthy diet
• Trying to ensure that the house is quiet when you try to sleep or use ear plugs
• In the summer months, trying to ensure that the room is cool, as people tend to sleep better when the temperature is reduced
• Avoiding watching television in bed

Over the counter or prescription medication may also impact on the quality of sleep. 

What can the workplace do?

Employers have a duty of care to ensure that their workers are not exposed to hazards. Fatigue is one such risk, and shifts need to be carefully managed by employers to ensure that their workers aren’t working while fatigued. Workers also have a responsibility to ensure that they are getting enough sleep each night.

Employers need to address workplace hazards and safety risks in a systematic way. This could begin with raising employee awareness of their responsibilities, as well as exploring the lifestyles and individual choices which could contribute to fatigue or impaired performance.

If extended hours are common in the workplace, the employer could consider:

• Providing enough time between shifts for employees to sleep and recover. Factor in the time spent travelling and the time required for eating and washing, in addition to the time required sleeping.
• Scheduling shifts which are more aligned with people’s body clocks, avoiding higher risk times
• Avoiding extended overtime arrangements, and consider employing additional staff to reduce the overtime burden on pre-existing staff
• Offering flexible working hours
• Providing on-site accommodation and/or prepared meals
• Providing facilities for shift employees to sleep before driving home
• Avoiding split shifts where possible
• Avoiding last minute changes to rosters
• Avoiding having non-essential work conducted at night
• Encouraging workers to report concerns about levels of fatigue
• Rescheduling work to avoid times of extreme temperature. If work during this time is unavoidable, provide regulation rest and rehydration breaks in a cool area
• Maintain a safe, secure and well-lit work area
• Train managers and supervisors to take appropriate action if someone appears fatigued

Employers could also take action to prevent fatigue inducers such as:

• dim lighting
• limited visual acuity (due to bad weather for example)
• high temperatures
• high noise
• high comfort
• sustained and monotonous tasks
• repetitive, difficult, boring or monotonous tasks