All of us know what it’s like to be tired or sleepy. But what if you felt tired all day, every day? For many American workers, this is the norm. CDC data from 2007 show that 30 percent of American workers reported that they get 6 or less hours of sleep each day—not enough, according to sleep experts. Another study by researchers at Caremark found that during a two-week period, 38 percent of the U.S. work force reported low energy, poor sleep, and fatigue. The lost productivity costs billions of dollars and puts workers at increased risk of injury and health problems.

Three expert panels (from the American Academy of Sleep Medicine & Sleep Research Society, the American Thoracic Society, and the National Sleep Foundation) have concluded that adults need 7 to 9 hours of sleep per day. (The exact amount needed is a function of genetics, but few need less than 6 or more than 9 hours per day.) According to a study published in 2010, during the period 2004–2007, 30 percent of U.S. civilian workers reported sleeping 6 hours or less per day, up from 24 percent two decades earlier. In some industries, the problem is much worse: 70 percent of transportation workers and 52 percent of healthcare workers who work nights get 6 or less hours of sleep per day.
Why are Americans not getting enough sleep? Claire Caruso, PhD, RN, FAAN, a research health scientist with NIOSH, thinks there are five primary reasons:
  • they don’t know the importance of sleep
  • they have economic and social pressures to stay awake
  • they simply have too much to do
  • they suffer from sleep disorders (50–70 million Americans do)
  • they work shift work or more than 40 hours per week
Illnesses, medications, and personal factors can also contribute to poor sleep.

When you get less sleep than you need, the results are often slowed reaction time, reduced vigilance, reduced decision-making ability, poor judgment, distraction during complex tasks, and loss of awareness. Lack of sleep impairs performance in a manner similar to alcohol. The United States defines legal intoxication for purposes of driving as a blood alcohol concentration (BAC) of 0.08 percent or greater. Multiple studies have shown that being awake for 17 hours is equivalent to a BAC of 0.05 percent; staying awake for 24 hours is similar to a BAC of 0.10 percent. The safety implications are staggering.
Many workers in the 24/7 society have problems with sleep. Our ancestors’ days were dominated by the sun: they woke at sunrise to go to work and went to bed when night fell. But now people go to work at any hour and may even change their working hours every few days. The concepts of “sleep pressure” (the need for sleep) and circadian rhythm help explain why those who work non-traditional hours are at risk.
When people awaken, they begin building sleep pressure. This sleep pressure increases over the course of the day until they do go to sleep. During sleep, it falls. If people stay awake too long, they become overwhelmingly sleepy. If they don’t sleep long enough, they start the day with an elevated level of sleep pressure. It’s easy to see how prolonged working hours or “being on call” could contribute to sleep problems.
Our bodies have a built-in circadian clock that determines times of wakefulness and sleep. We are “programmed” to be awake during daylight hours. Light sends a signal to the back of the eye that tells us when to be awake. But not all light has the same effect. Blue light (a component of white light) has the strongest wakefulness effect on the circadian clock. (Unfortunately, computers, cell phones, and other electronics emit blue light.) Yellow, orange, and red light have little effect on the circadian clock. Our normal circadian rhythm would have us awakening about 7 a.m. and retiring about 11 p.m. There is also a slight dip in wakefulness from 1 to 3 p.m., which explains the tendency to fall asleep after lunch and the evolution of the siesta.
Our circadian rhythm and sleep pressure normally work together to control our sleep and waking hours in a near optimal pattern (see Figure 1). But when people work alternative shifts (afternoon, night, rotating, or extended), circadian rhythms cannot quickly adjust and are not synchronized with sleep pressure. As a night shift worker comes off his shift, he is typically exposed to sunlight (containing blue light), which tells his body it should be awake. But his sleep pressure continues to build. The result is that his body needs to sleep, but it can’t. Even a worker on the afternoon shift is affected by this lack of synchronization, though to a lesser extent. Factor in the need to interact with family and friends and the demands of a society governed by daylight, and needed sleep is often a casualty.

Figure 1. The optimal sleep-wake pattern.
Fifty to seventy million Americans suffer from a sleep disorder such as insomnia or obstructive sleep apnea. It’s a huge problem: statistics show that in the past month, 38 percent of Americans unintentionally fell asleep during the day and 4.7 percent fell asleep while driving. Many experienced difficulty concentrating and remembering things.
Harvard scientists estimated in 2012 that sleep deprivation cost American businesses $63.2 billion per year. Nine percent of workers admit they might fall asleep at an inappropriate time such as during a meeting. Many companies have given their employees training in how to get a good night’s sleep and consider it the employee’s responsibility to come to work rested. But it’s difficult to do that when an employee is called into work at a time he should be sleeping because a piece of machinery broke or another employee didn’t show up.
To effectively address the things that keep employees from getting needed rest, employers, managers, and employees must share the responsibility. Many companies are beginning to use Fatigue Risk Management Systems (FRMS), a scientific, data-driven, cooperative approach to the problem. Analogous to a safety management system, an FRMS offers five levels of defense against a fatigue-related injury:
  1. balancing workload and staffing to limit “emergency call-ins”
  2. scheduling shifts to work with the employee’s circadian clock
  3. training employees on fatigue (including good sleep habits) and sleep disorder management to ensure sleep disorders are treated
  4. designing the workplace environment to help people stay awake, give them needed rest breaks, and mitigate the effects of attention loss
  5. monitoring fatigue and fitness for duty by both employees and their supervisors
The Dow Chemical Company is addressing fatigue within its Total Worker Health Initiative, which launched this year. According to Karen Millison, CIH, CSP, a lead industrial hygiene manager at Dow, one aspect of the initiative aims to assess and improve health culture and includes a comprehensive questionnaire based on the U.S. CDC Worksite Health Scorecard. The annual questionnaire includes questions about flexible work options, dedicated “quiet spaces” for relaxation activities, employee participation in organizational decisions that affect job stress (such as job schedules), resiliency and stress management programs, and the availability of a nearby space for physical activity with at least one piece of equipment to promote movement.
Dow tailors its Total Worker Health Initiative to each site, considering operational and business needs, work force needs, culture, local regulations, and other factors. Approaches to address fatigue and shift work at Dow sites include:
  • a policy restricting the number of working hours; exceptions must be documented and approved
  • fatigue management checklists, including training and self-assessments for employees as well as leader checklists, which can help identify gaps in the management system
  • an alertness recovery room (a quiet space), which can be used for a short time (20 minutes) by workers on night shift to nap or rest
  • exercise equipment
In addition, global expertise and resources are available, including health tips for shift workers, guidance for leaders who manage shift work, and clinical guidelines for healthcare providers to identify potential sleep disorders.
One of the most unrecognized issues in American culture is drowsy driving. Although most people wouldn’t think of drinking and driving, almost everyone has driven when tired, and the effects are similar. Individual drivers can usually pull over and rest if they are tired. But what if you drive for a living and people are counting on your bus or train being on time?
The Washington Metropolitan Area Transit Authority (WMATA), which operates the Metrorail and bus service in the U.S. capital, takes a slightly different approach with its Fatigue Risk Management System. Korrie Mapp, CPE, FRMS Manager, explained the four elements of the program: an hours of service (HOS) policy, fatigue training, medical services and wellness, and application of a Safety Management System to fatigue.
While there are hours of service rules for the transportation industry, they alone do not solve the fatigue problem. WMATA’s five HOS metrics go hand in hand with other elements of its FRMS program to decrease the risk of fatigue. WMATA defines these metrics as:
  • shift service: a worker who is on duty more than twelve hours
  • workday duration: a tour of duty that exceeds fourteen hours
  • release period: an off-duty period that is less than ten hours
  • consecutive days: work for more than 6 straight days
  • 65-hour metric: employees who work more than 65 hours per week for a seven-day period
WMATA gathers information from each of its departments on these fatigue metrics, interprets them, enacts a plan when one or more metrics is out of the desired range, and then encourages the group to institute changes. Making management aware of the problem and reporting the results helped tremendously, Mapp says: within two months of formally reporting WMATA FRMS metrics, key departments experienced at least a 90 percent decrease in one HOS metric.
The supervisors and employees of WMATA also receive fatigue training. Some of the training is computer- based and some is instructor-based. All training is tracked; problems are noted and corrected. Newly hired employees also receive the training.
Mapp says the medical services and wellness portion of the FRMS is critical. Transportation workers tend to be more obese than other workers, a major risk factor for the incidence and chronicity of excessive daytime sleepiness. Weight management and diagnosis/treatment of sleep disorders play a big role in fatigue reduction. WMATA also offers stretching programs, yoga, activity monitors, and quiet rooms/sleep pods to its employees.
Finally, WMATA tracks incidents and collects relevant data where fatigue may have been a contributing factor. The data analysis helps WMATA re-evaluate the effectiveness of the system.
No one is going to end fatigue on the job anytime soon. The problem is complex, and solving it involves overcoming long-held misconceptions, including:
  • People can recognize their own poor performance due to sleep loss.
  • People who are experienced working on little sleep can compensate.
  • Motivation and professionalism can overcome sleep deprivation.
  • Some people just don’t need much sleep.
  • If employees don’t get enough sleep, it’s their own fault.
As organizations like Dow and WMATA lead the way in managing fatigue risk, others will hopefully follow. The need exists, and the cost in both dollars and human terms is quite compelling.
is a consultant at Ergonomics Applications in Salem, S.C. She can be reached at (864) 944-8111 or

Centers for Disease Control and Prevention:
Work Schedules: Shift Work and Long Hours
Sleep and Sleep Disorders
Worksite Health ScoreCard

Journal of Occupational and Environmental Medicine: “ACOEM Guidance Statement: Fatigue Risk Management in the Workplace” (
, February 2012).

National Sleep Foundation
NIOSH Training for Nurses on Shift Work and Long Work Hours
(May 2015).
For research and tips on drowsy driving, see
National Highway Traffic Safety Administration
National Center on Sleep Disorders Research
and the
U.S. Department of Transportation
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Night's Sleep
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Workplace Fatigue and the 24/7 Society