In this article, Robson Forensic experts in Human Factors and Industrial Safety discuss some of the risks associated with shift work and other non-traditional work schedules.
Asleep at the Assembly Line: Shift Work, Sleep Deprivation, and Industrial Accidents
Did you know?
Some of the most devastating human and environmental health disasters have been partially attributed to fatigue, sleep loss, and night shift work-related performance failures, including the tragedy at the Union Carbide chemical plant in Bhopal, India; the nuclear reactor meltdowns at Three Mile Island and Chernobyl; and the grounding of the Exxon Valdez oil tanker.
Sleep-deprived workers are 70 percent more likely to be involved in work-related accidents.
Workers reporting disturbed sleep and excessive daytime sleepiness are almost twice as likely to die in a work-related accident.
The effects of shift work on workers ability to sleep costs the U.S. almost $4B per year in associated costs of work-related accidents, injuries, and lost productivity.
The effects of sleep deprivation
Sleep deprivation not only affects a person’s health, it also affects their ability to safely operate equipment and motor vehicles. The effects of sleep deprivation on workers include:
- Increased reaction time
- Decreased alertness
- Degraded attention and vigilance
- Decreased motivation
Shift workers are even more susceptible to the effects of sleep deprivation than an average day-shift worker because of disruptions to their natural sleep patterns by working nights or long and irregular hours.
The graphic below shows the times of day when a worker is most susceptible to the effects of sleepiness based on the body’s circadian rhythm. Workers are most susceptible to sleep-related accidents between midnight and 8am.
A normal work shift is generally considered to be a work period of no more than eight consecutive hours during the day, five days a week with at least an eight-hour rest. Any shift that incorporates more continuous hours, requires more consecutive days of work, or requires work during the evening should be considered extended or unusual. Extended shifts are often used to maximize scarce resources. Long or unusual shifts are often required during response and recovery phases of emergency situations such as natural disasters, which generally come with little to no warning, require continuous monitoring, and may overwhelm local responders both technically and tactically. These schedules ensure that the appropriate scarce resources are in place and accessible while full mobilization is being developed.
Currently, there is not a specific OSHA Standard for extended or unusual work shifts. However, when there is a choice with respect to implementing unusual or extended work shifts, management should consider the following:
- Limit the use of extended shifts and increase the number of days employees work. Working shifts longer than 8 hours will generally result in reduced productivity and alertness.
- Provide additional break periods and meals should be provided when shifts are extended past normal work periods.
- Perform tasks that require heavy physical labor or intense concentration at the beginning of the shift if possible. This is an important consideration for pre-emergency planning.
- Learn to recognize signs and symptoms of the potential health effects associated with extended and unusual work shifts. Workers who are being asked to work extended or irregular shifts should be diligently monitored for the signs and symptoms of fatigue which may include sleepiness, irritability, and lack of motivation, for example. Any employee showing such signs should be evaluated and possibly directed to leave the active area and seek rest.
- Whenever feasible, ensure that unavoidable extended work shifts and shift changes allow affected employees time for adequate rest and recovery. Extended shifts should not be maintained for more than a few days, especially if they require heavy physical or mental exertion.
- Plan to have an adequate number of personnel available in order to enable workers to take breaks, eat meals, relax, and sleep. If at remote sites, ensure, as far as possible, that there is a quiet, secluded area designated for rest and recuperation.
- Plan for regular and frequent breaks throughout the work shift. In addition to formal breaks such as lunch or dinner, encourage the use of micro breaks to change positions, move about, and shift concentration.
Investigating sleep-related industrial accidents
The role that sleep deprivation and/or shift work may have played in an industrial accident is a complex issue that requires experts with specialized knowledge and expertise in the areas of sleep deprivation and human factors as well as industrial health and safety. To overcome these challenges, our experts use a combination of accident analysis techniques, knowledge of human behavior and performance, and experience investigating industrial health and safety violations to determine the relevant factors in an accident.
Dr. Nancy Grugle is an expert in human factors with significant research experience in the area of sleep deprivation. Dr. Grugle has investigated the effects of sleep deprivation on human performance at the Walter Reed Army Institute of Research and also conducted human factors research while an Assistant Professor of Industrial and Manufacturing Engineering at Cleveland State University. Dr. Grugle received competitive research grants from the National Science Foundation, the Ohio Department of Transportation, and the Cleveland State University Transportation Center and has been published in national and international peer-reviewed journals. Her combined expertise in both sleep deprivation and human factors can be applied to cases involving industrial accidents, drowsy driving, aviation, and medical errors.
Ron Schaible is an expert in occupational health, safety, indoor environmental quality, ergonomics/human factors, and training issues. For 29 years in insurance loss control and private industry, he constantly applied his knowledge and experience in environmental and occupational health and safety services to eliminate or minimize risks to people, products, and the environment. He’s familiar with OSHA and numerous EPA regulations and product warning issues. Ron is an active college instructor in his field with more than 18 years teaching experience, and has earned eight different certifications and registrations, including Certified Industrial Hygienist (CIH) in Comprehensive Practice, Certified Safety Professional (CSP), and Certified Professional Ergonomist (CPE). He’s a Diplomat of the Academy of Industrial Hygiene, a member of the American Society of Safety Engineers and the American Industrial Hygiene Association.