Sleep Deprivation and Workplace Safety
Some of the most sleep-deprived workers in America are also working in the most dangerous industries. When the National Institution of Occupational Safety and Health (NIOSH) conducted a survey of sleep habits by occupation, they found that many safety-sensitive workers were living on a short sleep schedule (less than 7 hours a night). That includes:
- 7% of rail transportation workers
- 5% of material moving workers
- 5% of motor vehicle operators
- 9% of production workers
- 3% of extraction workers
- 5% of construction/trades workers
- 8% of firefighting and prevention workers
- 40% of healthcare practitioners and technicians
- 1% of healthcare support workers
These are all jobs that require vigilance to keep yourself, your colleagues, and the general public safe. So what effect is sleep deprivation having on those workers and the safety of their workplace?
How Dangerous Is Sleep Deprivation in the Workplace?
How dangerous are tired workers? Let's look at some of the data:
- Research suggests that around 13% of all work injuries could be due to sleep problems.
- Highly fatigued workers are 70% more likely to be involved in accidents.
- Workers that sleep less than 5 hours a night have more than 3 times the rate of injury than those who sleep 7-8 hours.
In fact, sleep deprivation can be just as bad as coming to work drunk. After 17 hours of wakefulness, your reaction time, memory, hand-eye coordination, and other metrics are the same as someone blowing a .05% BAC.
After 19 hours, your performance is equivalent to having a BAC 0.10%. Many of the most infamous workplace accidents are entirely or partially due to drowsiness or fatigue, including:
- Nuclear accidents like Chernobyl and Three Mile Island
- Oil industry disasters like the Exxon Valdez and BP's Texas City refinery explosion
- Numerous transportation incidents, including multiple train wrecks, American Airlines Flight 1420, and the space shuttle Challenger explosion
6 Dangerous Effects of Workers Not Sleeping Enough
What makes sleep deficiency or deprivation so risky? Let's look at a few of the many effects.
Safety Hazard #1: Sleep-Deprived Workers Have Poor Motor Skills
Tired workers have slower reaction times, impaired hand-eye coordination, poor balance, and other motor skill deficits that make accidents more likely. That makes it dangerous for sleep-deprived individuals to operate heavy machinery, whether it's a delivery truck, construction equipment, or factory machinery.
The lack of balance and coordination makes it more likely for construction workers and other personnel to experience a dangerous fall. It also creates a safety hazard for any task that depends on fine motor control, like proper use and disposal of needles in healthcare practice.
Safety Hazard #2: Sleep Deprivation Impairs Workers' Memory
A lack of sleep causes workers to have trouble retaining new information. Whether you're experiencing total sleep deprivation (continuous consciousness) or a long period of restricted sleep (four to six hours a night), the effect is the same.
Multiple studies have shown that sleep deprivation cripples your working memory (otherwise known as short-term memory). It can undermine the accuracy of your memory, the speed with which you recall accurate information, or both.
For someone performing non-critical database entry, these errors and inefficiencies are annoying but mostly harmless. For someone manning the controls at a nuclear power plant, operating or repairing aviation equipment, or updating patient charts in a healthcare setting, those lapses are a huge safety threat.
Sleep deprivation also affects your ability to consolidate that day's events into long-term memory, because this normally happens during deep sleep. Workers who are sleep-deprived will have trouble recalling new facts or experiences.
Safety Hazard #3: Insufficient Sleep Leads to Increased Risk-Taking in the Workplace
A study from the University of Zurich found that sleeplessness is a safety threat because it causes you to make increasingly risky decisions. What's worse: you don't even know that you're doing it.
Study subjects rated their sleep-deprived decision-making abilities to be the same as their regular behavior when objective data showed that it wasn't.
For workplace safety, this means sleep deprivation may lead construction, manufacturing, or healthcare workers to forego personal protective equipment or safety protocols and believe they're making a reasonable choice.
It also means that tired workers are less likely to catch up on the sleep they need to function well – sleep-deprived people believe that they're doing just fine without enough sleep. They believe they've "adapted" to less sleep even though their actual performance continues to get worse.
Safety Hazard #4: Lack of Sleep Deteriorates Workers' Emotional Control
Anyone who's been around a tired toddler knows that a lack of sleep makes you cranky. In fact, it's bad for your emotional regulation altogether. Sleep deprivation makes you impatient, quick-tempered, and prone to wild mood swings.
In the long term, it can lead to depression, mania, and other forms of mental illness. Why is this effect of sleep deprivation a safety issue? Workplace safety relies heavily on communication and cooperation among workers.
When everyone is tired and irritable, that tension causes safety to take a back seat to interpersonal conflict.
Safety Hazard #5: Workers May Fall Asleep on the Job
The most obvious and dangerous consequence of running a sleep deficit is that workers may fall asleep during work hours. Boring, repetitive, or overly familiar tasks increase the risk.
It might be a conscious choice to take a nap that has them missing a sign of danger – that's what happened to the Exxon Valdez. They may also fall asleep involuntarily, like a trucker that nods off behind the wheel until their tires hit the rumble strips.
It's also possible – even likely – that tired workers will lose consciousness and not know it. When your brain is sleep-deprived, it shuts itself down for brief periods called microsleep. You may interpret it as "spacing out" or "losing time," but in many cases, you don't even realize it's happening unless it ends in disaster.
Safety Hazard #6: Sleep Deficiency Causes Workers' Overall Health to Decline
We've been talking about immediate threats to health and safety posed by a lack of sleep. But there are plenty of long-term effects, as well. Chronic sleep deficiency leads to a higher likelihood of obesity, high blood pressure, heart disease, dementia, mental illness, diabetes, colorectal cancer, stroke, and much more.
In fact, getting five hours or less a night increases your mortality risk from all causes by 15%. Workers' poor health can represent a distraction and safety risk all their own. Sleep deprivation also suppresses your immune system, making you three times more likely to catch a cold.
From a workforce management point of view, that means a lot more absenteeism and a vicious cycle of additional shifts for workers that are well.
What Factors Cause Workplace Fatigue?
It's not just a total lack of sleep – like a 48-hour shift – that puts workers' safety at risk. Other working conditions create the same levels of fatigue (and danger).
Overnight or Graveyard Workers Face Unique Safety Risks
Your body has two systems that tell you when to sleep. The first is the one you're more familiar with: your circadian rhythm. Most people experience "peak sleepiness" between midnight and 6 am.
That's why night (or evening) shift workers are at particular risk. Even if they've gotten the recommended 7 to 9 hours of sleep, they'll experience symptoms of fatigue during work hours. Additionally, it's rare that overnight workers do get adequate sleep since most are fighting their circadian rhythm to sleep during the day.
That's why, according to OSHA, accident and injury rates are 30% higher during night shifts than day shifts. Even for the evening shift, it's 18% higher.
Extended Hours Threaten Worker Safety
The second system that makes you sleepy depends not on the time of day but on how long you've been awake. As your cells use energy, they release a byproduct called adenosine.
Your brain reacts to this compound by making you increasingly drowsy – dimming things like mental focus and the ability to react to signals. When you sleep, your body has time to break down the adenosine you made during the day. That's why a full night's rest makes you feel alert.
All in all, this explains a few things you've undoubtedly experienced for yourself:
- You'll become increasingly less alert the longer you're awake
- The harder you're working, the faster you'll become drowsy
- To get back to peak alertness, you need to get enough sleep
It's a chemical reaction that can't be cheated. Research has shown that working a 12-hour day carries a 37% increase in the rate of injury. And the more time a worker puts in, per shift or per week, the higher the risk.
Chronic Sleep Deficits Represent an Increasing Safety Hazard
You're probably aware that when you sleep, you experience a sleep cycle: light sleep, deep sleep, and REM sleep. Deep sleep promotes physical recovery (like tissue repair) and REM sleep promotes mental recovery.
What you may not know is that deep sleep mostly happens early in the night, in the first 2-3 hours of sleep, while REM sleep happens later in the night. That means if you're sleeping less than the recommended amount, your brain isn't getting the reset it needs.
Research has shown that the longer you go on limited sleep, the worse your motor skills, problem-solving abilities, memory become until you catch up on sleep.
Why Does a Lack of Sleep Affect Performance?
What it boils down to is that a lack of sleep makes your nervous system sluggish. One small study out of UCLA looked directly at brain activity during sleep deprivation. They found that when participants were sleep-deprived, the normally rapid-fire of brain cells lagged behind in response to stimuli, dragged on for a longer period of time, and were weaker in strength.
That slows down your cognitive abilities and your reaction to outside stimuli. The temporal lobe of the brain was especially slow – that's where you process visual input. When you're too tired, your brain literally has trouble making sense of what's in front of you…whether that's a pedestrian, a warning light, or patient vitals. Once it does register, the rest of your brain would take longer to assign meaning to what you're seeing and react.
The study also found evidence that parts of your brain fall asleep on their own. Specifically, slow brain waves (associated with sleep) disrupted activity in some regions. If that's true, it could explain lapses in memory and concentration.
Safety Beyond Sleep Deprivation
Of course, sleep isn't the only thing that factors into workplace safety. Being well-rested is extremely important, but unless workers understand the health and safety hazards in their workplace (and how to avoid them), they run a high risk of injury or work-related illness.
This is why OSHA requires regular safety training for all U.S. workers. We've been an OSHA-authorized online training provider for over 20 years.
Check out our mobile-friendly, self-paced OSHA 10 and OSHA 30 courses as an introduction to OSHA training. We also have a full catalog of standard-specific courses that are required for specialized types of work.