The lethal connection between falls from height and sleep deprivation

Working at heights remains one of the most intrinsically dangerous industrial activities. A fall from heights means, if not certain death, a serious and perhaps crippling injury. Yet despite this, many organisations still face a tough time getting workers to use fall protection.


According to the UK’s Health and Safety Executive (HSE), two thirds of fatal injuries to workers are caused by only four kinds of injuries – one of which is falls from height. Falls, slips and trips combined made up more than half of all reported major injuries, and almost a third of injuries lasting more than three days.

Experts agree that the best way to protect against injuries caused by falling from heights is to avoid working at height in the first place, but it is seldom that simple. In many parts of the world, working at height is a one of the most common occupational requirements. This is particularly prevalent in the construction sector, but working at height injuries are also common in agriculture, oil and gas and even service industries.

According to the HSE, an average of 50 people die in Great Britain annually because of falls from height. In 2012 the HSE reported that 26% of all fatal construction site accidents were caused by falls from height. What’s more, although injuries caused by falls from height represent only 13% of the overall injuries, a staggering 53% of fatalities were caused by falls from height.

Compliance issues

While very little research has been conducted to determine the exact cause of these falls it is fairly certain that most, if not all of these injuries could have been prevented had the workers properly used fall protection. As with all personal protective equipment (PPE), the most common failure is a lack of worker compliance.

Given the dangers faced when working at heights, a lack of compliance seems insane. After all, what possible reason could a worker have for taking such a reckless risk? Often workers decide that fall protection is unnecessary because they believe that falling from heights is a problem limited to the construction industry, or because they don’t consider the height at which they will be working high enough to cause injury.

According to the QBE Insurance Issues Forum, however, 59% of major injuries occur following a fall from height of less than two metres, and 61% of more than three day injuries occur within the service industry.

Sleep deprivation

Before you blame the worker, or even the PPE itself for workplace incidents, consider that the worker may be sleep deprived. Often, when a worker is confronted for violating the policy requiring fall protection, he or she will likely shrug and say, “I forgot.” Forgetting to wear gear that is so much a part of the work routine may sound like a lame excuse, but it may not be. Many safety professionals are realising that human errors, behavioural drift and even recklessness can be traced to a growing threat to workplace safety –a lack of sleep.

Many of us worry about not getting enough sleep, but just how harmful is a lack of sleep? As detailed in the following points, the short answer is – very.

A lack of sleep is as dangerous as alcoholic impairment. Experts contend that when someone has been awake for 21 hours, he/she will perform at a level of impairment roughly the same as a person with a blood alcohol level of 0.08%. Obviously, companies would never condone a worker who is under the influence of alcohol working at heights, yet these same organisations often knowingly allow sleep deprived employees to work in this condition.

Just like alcohol or drug use, a lack of sleep increases risky behaviour. Dr Chan’s 2012 research found that a workplace incident is four times more likely to be caused by fatigue then buy alcohol or drug impairment.

As outlined in the following sections, this impairment may endanger workers in several ways.

Impeded judgment

Sleep deprivation impedes the worker’s judgment, and it may cause an otherwise compliant worker to choose not to wear fall protection equipment. A sleep deprived worker is also far more likely to misjudge the height at which he/she is working, causing the previously mentioned reasoning that fall protection equipment is not necessary.

Lack of manual dexterity

A sleep impaired worker is far more likely to struggle to wear the fall protection equipment properly. While most fall protection is easy to put on and properly fasten, the loss of manual dexterity typically associated with sleep deprivation may make improperly installed protection more common. The lack of manual dexterity coupled with slowed reactions may also prevent workers from acting in time to prevent a fall.

Lack of alertness

The drowsiness associated with sleep deprivation can jeopardise the safety when working at height in two ways: firstly, a sleep deprived worker is more likely to miss damage or other flaws in the pre-use inspection of the PPE, and secondly, this lack of alertness increases the probability that a fall will occur. The combinedeffect is a worker potentially using damaged PPE precisely when protection is needed the most.

Increased injuries

Even if we were to design completely fool proof fall protection equipment, sleep deprivation threatens workers in ways that PPE can’t protect against. According to a 2010 study by the University of British Columbia, Canadians who worked night and rotating shifts were almost twice as likely to be injured on the job when compared with those working regular day shifts.

Multiple sources list fatigue as one of the top five causal factors in workplace incidents (Chan, 2010), so while experts may attribute upward of 90% of workplace injuries to unsafe behaviour, most fail to answer the question of why a worker behaved unsafely. Increasingly, that answer is linked to a lack of sleep.

A fatigued worker is far more likely to miss critical steps in a process, such as ensuring they are wearing appropriate fall protection, keeping the fall protection equipment in good working condition, and choosing the right locations to which they tie off.

Vegso et al (2007) found an 88% increased risk of an incidents for individuals working more than 64 hours a week. As employers try to do more work with fewer workers, workers are often forced to work while sleep deprived. As workers tire they make more mistakes and riskier choices.

Extent of the threat

So, just how widespread is the threat? Considering that almost a third of us don’t get enough sleep, the problem is at epidemic proportions. In 2012, the US Centers for Disease Control and Prevention reported that 50 to 70 million American adults suffer from sleep and wakefulness disorders.

Similar studies in the UK not only found that many people suffer from a lack of sleep, but also that sleep deprivation can interfere with people’s ability to perform demanding cognitive tasks. When a worker is at height, decisions relative to tying off, for example, could be undermined to the extent that the worker effectively has no protection from falls whatsoever.

Little sleep, lower compliance

UK studies also found that too little sleep caused an increase in irritability. This increase in irritability makes it more likely that workers will deliberately violate rules that they find objectionable, refuse to wear fall protection equipment that they feel is unwarranted or that they dislike because it is uncomfortable – or just to be plain obstinate.

The UK studies also found that a lack of sleep caused perceptual disturbances – a difficulty seeing or hearing, for example. These perceptual disturbances can easily cause a worker to justify violating fall protection requirements because they have erroneously judged the height at which they will be working as safer than it actually is.

Poor decision making

According to Hallinan, even moderate sleep deprivation can cause brain impairment equivalent to driving while drunk – and has been shown to significantly increase an individual’s willingness to take risks.

In effect, sleep deprived workers make more mistakes, poorer decisions, and take more risks – all things that have been repeatedly shown to increase the probability of worker injuries.

British researchers reached a similar conclusion and in one study found that “Sleep loss has a primary effect on Sleepiness and Sustained Attention with much smaller effects on challenging Working Memory tasks.” In simpler terms,the research found that workers are far more likely to forget rote tasks – like wearing PPE – when they were deprived of sleep on a regular basis.

Lack of sleep makes us sick

According to lack of sleep has been tied to mental distress, depression, anxiety, obesity, hypertension, diabetes, high cholesterol and certain risk behaviours including cigarette smoking, physical inactivity and heavy drinking.

The National Sleep Foundation found that after seven days of too little sleep the body undergoes genetic changes to as many as 700 genes. What’s more, researchers still don’t understand exactly the implications of these genetic changes. Clearly, sleep deprivation is far more dangerous than many people realise.

Despite the dangers, there are very few legal requirements that govern the lack of sleep for most workers and of those trades typically governed – healthcare workers, airline pilots, and truck drivers, for example – the workers aren’t the most likely to die from a fall from height.

In fact, in most municipalities, the legal duties incumbent on organisations are fairly vague and most fall in one of the following categories (where it is reasonably practicable):

• Avoid working at heights • Prevention of falls • Minimise the consequence of the fall

While working at heights regulations require those insured to ensure that their health and safety management systems

• Enable them to plan all work at height • Apply the hierarchy of control measures • Select the right people and equipment for the task • Train persons doing the work • Inspect and maintain equipment used • Ensure supervision and monitoring of work as per the plans set out

There are no specific requirements that those working at heights be fit for duty. The closest thing there is to such a requirement is the provision “work at height must be ‘carried out in a manner which is so far as is reasonably practicable safe’.”

Obviously, work performed at heights by a sleep deprived worker is not being carried out in a manner that is safe, but is it reasonably practicable to expect organisations to manage sleep deprivation?

Recognising the signs

Managing the sleep deprived can be challenging, but considering that the impairment can be as significant as that of alcohol use it’s important not only for the safety of the sleep deprived, but other workers as well.

When it comes to sleep deprived employees there really isn’t a meaningful distinction from other signs of unfitness for duty:

• Sudden changes in appearance. The sleep deprived employee may seem to lose interest in their appearance. A normally neat and appropriately dressed worker who suddenly reports to work dishevelled may be unfit for duty. Managers have a right and responsibility to assertively confront the worker and have a frank conversation about the worker’s fitness to work

• Increased mistake making. A worker who has otherwise shown competency at his or her job who then becomes prone to errors may be showing signs of sleep deprivation.

Managers should investigate the causes of this sudden drop in performance

• Increased lapses in judgment. Just as the sleep deprived worker will make more mistakes, a worker with normally sound judgment will show more incidences of poor choices and bad decision making

• Irritability. A lack of sleep will make a usually good natured worker ill tempered and irritable. Many workers who are branded as having a bad attitude may simply not be getting enough sleep

Willing but unable

Sleep deprivation in the workplace shows no signs of abating, but there’s still hope.

Organisations should educate workers in ways that they can get enough restful sleep.

Experts at the National Sleep Foundation and elsewhere are resources in this effort and offer tips for getting a good night’s sleep:

1. Don’t sleep in at weekends – maintain your weekday sleep schedules.

2. Wind down. Experts recommend that people establish a regular relaxing routine to transition between waking and sleep. Soaking in a hot tub and then reading a book before retiring can greatly improve the quality of sleep one gets. Make your bedroom sleep friendly – dark, quiet, comfortable and cool.

3. Use your bed for sleeping. Experts warn that watching television or working on a computer can impede your ability to truly relax when it comes time for sleeping.

4. Avoid caffeine, nicotine and alcohol for several hours before bedtime.

5. Allow enough to time for sleep. Before you raise your hands in protest that you would if you could, consider that people who get enough sleep are significantly more productive than those who are deprived.

6. Nap. A 20 minute (no more) nap followed by exercise will make you feel refreshed and provide you a pick-me-up that will make you more productive.

7. Finish eating at least two to three hours before your regular bedtime.

8. Exercise regularly and complete your workout a few hours before bedtime.

9. Recognise that one of the most common reasons for insomnia is worrying about not getting enough sleep. Lying quietly with one’s eyes closed can be very restorative, and while it is not as healthy as deep REM sleep, it can be a short term solution to the sleep deprivation problem.

Dr Charles Samuels, the medical director at the Centre for Sleep and Human Performance in Calgary, Alberta, offers some additional tips for avoiding sleep deprivation and fatigue:

1. Determine how much sleep you need to feel well rested on a daily basis. Multiply that number by seven. The resulting number is the amount of sleep you need per week.

2. Determine how much sleep you get. Add up the total amount of sleep you get on day/afternoon/evening shifts per week and night shift per week. Then determine your sleep debt in each situation by subtracting those numbers from your sleep need.

3. Focus on minimising your total sleep debt by taking the following actions:

Improve your day sleep environment

Catch up on your sleep on your days off

Learn to catnap

Sleep longer during the day when you have a night rotation or tour of duty

4. Give yourself a quiet, completely dark, comfortable day sleep environment with no distractions.

5. Try to get two three to four hour blocks of sleep during the day when you work the night shift.

6. Learn to catnap. Take a short 20-30 minutes of time with eyes closed, situated in a comfortable resting position. You do not have to sleep to get the benefit of a catnap.

7. Remember – the treatment for sleepiness and fatigue is SLEEP!

Safety professionals should raise the awareness of this problem among workers and share these tips for getting enough sleep, especially on the night shift. But if workers ignore these suggestions and continue to deprive themselves of sleep to the extent that they become a danger to their safety and the safety of others, the supervisors have no choice but to intervene. As ridiculous as it may seem, workers may need to be disciplined for not getting enough sleep.

There is no way of definitively knowing the full connection between sleep deprivation and falls from heights. It would, however, be foolish to discount the impact the profound effects can have even from short term sleep deprivation. Someone working at height should have no impairment to manual dexterity, judgment, or the ability to verify one’s correct usage of the protective equipment – much less be more prone to risk taking.

Published: 19th Mar 2014 in Health and Safety International