MRO Magazine

The Night Shift: Experts warn of danger of shiftwork in industrial settings


June 14, 2001
By PEM Magazine

It’s no coincidence that the most notorious industrial accidents of our times — Three Mile Island nuclear accident, the Bhopal, India poison gas leak, the Chernobyl reactor meltdown, and the Exxon Valdez oil spill — all occurred in the middle of the night, during the "graveyard shift", when the people with hands-on responsibility were dangerously fatigued.

Today an estimated 25 percent of the workforce in Canada works some form of shiftwork, and this percentage is growing. As automation in any industry increases, the shiftworker is becoming a more highly skilled monitor of an automated process and — one would hope — a vigilant one. But the role of a shiftworker is often one of passive vigilance rather than active involvement, which makes him or her much more vulnerable to the effects of fatigue and sleepiness.

In 1990, a Stanford University study surveyed 7,000 individuals from 21 different industries. The study asked a basic question: "In any given week, when you are supposed to be working, do you ever fall asleep?" Across industries, between 50 and 60 percent of individuals reported problems with significant sleepiness during their respective work shifts. In addition, 50 to 60 percent of individuals reported sleepiness to be a factor in relation to poor performance and observed safety violations. Automation can make the consequences of such human errors significantly more damaging and catastrophic.

Ask shiftworkers what their biggest problem is, and you’ll get one answer loud and clear: "sleep". Our internal body clock influences our ability to fall asleep and get into the right stages of sleep, and our ability to stay awake during our "awake time." To a great extent, our body clock controls how wide-awake we feel.


Quite commonly, the shiftworker is trying to fight against what his biological clock is pushing him/her to do. Unfortunately for the shiftworker, the clock is also quite slow to change after a shift in schedule. Until it makes the change, it expects sleep at the wrong time of the day for the worker, and shuts down alertness, appetite, and digestion when they should be operating at full capacity. When the worker is trying to sleep, the alerting processes are still going full tilt, interfering with sleep significantly.

The good news is that over the last 20 years an extensive amount of science in the area of sleep and the biological clock has made it easier to adapt to 24-hour operations, both from the individual and the corporate perspective. A judicious proactive approach to fatigue management in the workplace can result in significant improvement to the individual’s quality of life, while also increasing safety and productivity in the workplace.

Let’s face it — shiftwork is unnatural. But for anyone who must sleep in the daytime and work at night, following the tips below can help. There is no one perfect system for everyone, however but following these guidelines with individual adaptation can make coping easier. Keep in mind that shiftwork is a lifestyle, not only a work schedule.

The shiftworkers’ Ten Commandments
1 Get enough sleep — make it a health priority.
2 Involve your family in overall coping strategies. Family support is crucial in protecting your sleep, appointment scheduling, and social-life adjustment.
3 Get to know some common-sense sleep hygiene rules (such as "no vigorous exercise just before bedtime").
4 If you work evening shifts, be cautious driving home. Do not stop for a late night drink to unwind. Night shiftworkers should be extra cautious driving home in the morning.
5 A little coffee early in the shift can help. Avoid caffeine and smoking in the last few hours, if you want to be able to sleep.
6 Pay attention to diet and proper meal timing on shifts.
7 Strategy for time off depends on your next rotation. If you continue the same shift, try to maintain the same sleep/wake cycle as much as possible. If you are changing shifts, start preparing for the new rotation.
8 For a long-term shift schedule, chronic use of sleeping pills is not the solution. If required for a short-term problem, a short acting medication can help.
9 Don’t be your worst enemy. It is tempting to resist change, overburdening yourself with overtime, moonlighting, and other commitments. Getting a higher pay does not make the shiftwork problems go away!
10 Encourage your employer to offer a Fatigue Management Program (FMP). The science of sleep and the biological clock can make coping much easier.

Adam Moscovitch, M.D., FRCP(C), ABSM, ABPN is the medical director of the Canadian Sleep Institute, a Calgary-based clinical and research centre of excellence. For more information on shiftwork and fatigue, contact Canadian Sleep Institute, Unit 300, 295 Midpark Way SE, Calgary, Alberta T2X 2A8; Phone: (403) 254-6400, Fax: (403) 254-6403.

This article first appeared in the May/June 2001 issue of PEM‘s sister publication, Canadian Occupational Safety magazine. If you would like to learn more about Canadian Occupational Safety, visit