In today's tight labor markets, you need to be aware of how the demand for overtime can lead to a negative and dangerous cycle. Excessive overtime causes employee burnout and increases safety incidents. It also damages productivity, health and morale - which increases sick days, tardiness, absenteeism and turnover. This, in turn, creates a greater need for overtime and the cycle repeats itself.

Mandatory overtime raises uncomfortable safety and health questions. It's not unheard of for workers to be engaged in day after day of 18-hour workdays. In addition to on-the-job safety and performance problems, the result can be incidents and near-incidents on the commute home.

Even when overtime isn't excessive, it's important for the health and safety of your employees to monitor overtime practices in your operation. Watch out for "overtime hogs" and for individuals who seem to be perpetually fatigued. You'll need to educate them about the risks of fatigue and the steps they can take to handle long work hours.

So what can you do to minimize risks in the face of the overtime challenge?

First, you must develop and implement policies that prevent excessive overtime. Second, you can educate your employees to help them be better prepared for handling long hours.

Here are 12 tips to reduce the likelihood of safety and health problems:

1. Beware of the "excessive overtime cycle"
When overtime levels are too high, a counterproductive cycle quickly sets in. Workers always feel tired, making them prone to sickness or the need to take a "mental health day." When absenteeism rises, overtime increases, completing a cycle that further exacerbates the problem.

2. Set an annual cap
Although it's not uncommon for workers to work 500 or more overtime hours per year, 300 to 350 hours per year serves as a reasonable limit for employees who often work at night. This works out to about three 8-hour shifts or two 12-hour shifts per month. The Nuclear Regulatory Commission, in one of the few published recommendations on overtime, recommends that employees work no more than 260 extra hours per year.

3. Account for the "time of day" effect
Because the human body reaches a low ebb between 3 a.m. and 6 a.m., working during the overnight hours is much harder than working during the daytime.
Owing to this "time of day" effect, it's advisable to track overtime hours by night and day shift hours. If you use fixed shifts, you might want to have a lower annual cap for night crews than day crews. If you use rotating shifts, you should make sure that no more than half of an individual's overtime hours accrue during night shifts.

4. Avoid double shifts on eight-hour schedules
Double shifts making for 16-hour days are a bad practice, regardless of the hours they encompass. Except in emergencies, overtime on 8s should be limited to an additional four hours.

5. Use caution when holding workers beyond eight hours
Even when you set the maximum work shift at 12 hours, you need to be wary of safety concerns - both during the final part of the shift and on the drive home. Employees may be unaccustomed to working 12 straight hours. Plus, they don't get the days off for recuperation that a full-fledged 12-hour schedule provides.

6. With 12-hour shifts, restrict overtime to days off
It may be necessary at times to hold over a person for an hour or two while waiting for a relief worker to arrive, but you want to prohibit shifts that last 14 hours or more.
Overtime on 12s, then, should mean coming into work on a day off. In general, individuals should not work more than one additional shift per week. When you regularly bring in workers on their days/nights off, you forfeit the prime benefit of a 12-hour schedule - giving people more days off to rest and recover.

7. Watch out for "overtime hogs"
Even if all the overtime at your plant is voluntary, you need to watch for individuals who work excessive amounts. It's not uncommon for companies to have 20 percent of their employees working 80 percent of the overtime. Such a disparity should raise a red flag, since people who routinely log 60- or 70-hour weeks are candidates for fatigue-related errors.

8. Let people down easy
Don't try to solve the overtime hog problem overnight. If you establish a policy that immediately cuts workers' overtime in half, you risk financially hurting people who are often your most loyal employees. You need to make sure workers understand the basis for policy changes, and you should also build in steps that reduce overtime gradually.

9. Establish a formal rotation
If overtime is a regular feature of your operation, you should have some type of formal distribution system. This reduces the likelihood that you'll be shorthanded and prevents workers from feeling that a supervisor is playing favorites.
With most overtime systems, workers' names are placed on a relief list. When their name reaches the top, they have the opportunity to work overtime. To maximize the number of overtime opportunities, it's a good idea to move workers to the bottom of the list whether they accept or decline the chance for overtime.

10. Avoid "random" overtime shifts
To minimize disruption to workers' circadian rhythms, try to have the employees who come in on days off work the same shift they just finished.
Working a different shift increases the chances that an individual will end up reporting to work sleep deprived.

11. Consider six-hour OT shifts on off days
Some companies on 12-hour schedules call in two volunteers from home when they need to fill in a 12-hour slot. If you have a large pool of volunteers, this allows you to spread overtime to more people, and it also means you're less likely to wear out your employees.

12. Emphasize cross training
Some companies get into a bind because only a small percentage of the workforce is capable of handling certain repair work or other high-skill tasks. A few workers end up getting phenomenal amounts of overtime - whether they want it or not. Train employees to handle other jobs to distribute overtime evenly. It may also reduce the need to call people in for overtime.

Long night shifts

Long work shifts - whether due to overtime or 10- or 12-hour schedules - can be particularly challenging when they include overnight hours. Employees may already be lacking sleep, setting the stage for alertness lapses and safety problems.

Here's what employees can do to maximize alertness when they work long shifts, adapted from the February 1999, issue of Working Nights:

Make sleep a priority.
Getting enough sleep is vital because it's much tougher to make it through a long shift when you're sleep-deprived. To enhance daytime sleep, set up a separate room just for sleeping, eliminating light and noise. Many workers who can sleep for only a few hours when they get home find it beneficial to take a nap (or at least lie down for a while) before getting ready to return to work.

Exercise regularly.
Regular exercise - three or four 20-minute workouts per week - helps people fall asleep faster and sleep longer, increasing the amount of restorative deep sleep.

Take it easy on work days.
Set limits on what you do - eating, sleeping, and some time spent relaxing with family members. Save strenuous activities for days off.

Eat smart.
Eat healthy foods that provide energy. Examples include fruits, vegetables, bagels, pretzels, crackers and popcorn. Avoid high-sugar snacks such as candy bars that provide a temporary burst of energy and then cause you to crash.

Use caffeine wisely.
Caffeine provides a significant boost in alertness, but abusing it can lead to sleep and stomach problems. In general, consume no more than two or three cups per shift, and set a cutoff point within four or five hours of bedtime.

Exercise on the job.
A mini-workout during the night shift is tremendously helpful for breaking up the shift and providing an alertness boost. If you don't have access to exercise equipment, try jogging up and down several flights of stairs or find someplace where you can do push-ups and sit-ups.

Keep a positive attitude.
It's not always easy, but making a conscious effort to maintain a positive frame of mind will make work more pleasant. Negative thinking may make you feel lethargic.

Work wisely.
Tactics for making it through a tough shift include changing tasks often, doing work requiring moderate physical activity, doing enjoyable assignments at times of low alertness, and talking to coworkers.

Assess driver drowsiness.
A final key is for workers to take a few minutes to judge whether they're capable of driving home. If employees are too tired to drive, they should be encouraged to take a nap or make alternate arrangements to go home, such as a taxi or a ride from a co-worker.

Ed Coburn is publisher of the ShiftWork Alert and Working Nights newsletters. He is also managing director of Circadian Information (Cambridge, Mass.), part of Circadian Technologies, Inc., which offers publications, research, training, scheduling and consulting services for managers and workers in round-the-clock operations. He can be reached at (800) 878-0078; e-mail: ; or on the web at