When are workers most likely to become injured?

by on April 19, 2012 · 0 Comment POSTED IN: Workplace Safety Network

Everybody knows fatigued workers tend to be unsafe workers. That’s very old news.

But now a leading workers comp insurance provider has published startling statistics that shed new light on the fatigue factor, and also point to some interesting ideas about how strategic scheduling can improve safety.

What to look for
Here are some of the key findings in the report from the Liberty Mutual Research Institute for Safety, an arm of Liberty Mutual Group:

  • Factors like hours worked per shift, number of consecutive shifts and timing of breaks are just as important as total weekly or monthly hours in accident-causing fatigue.
  • Risk of injury rises dramatically after the eighth hour of a shift, quadrupling by the 12th hour.
  • The relative injury risk of night shifts is more than triple that of day shifts.
  • The amount of time between rest breaks has a sharp impact on injury risk. Where breaks were allotted every two hours, the last half hour before the next break was twice as risky as the first half hour after a break.
  • Risk of injury rises along with the number of successive shifts. This effect is particularly pronounced for night shifts.

For night-shift workers who worked four consecutive nights, the average risk relative to the first night was about 6% higher on the second night, 17% higher on the third night, and 36% higher on the fourth night.

The increase over successive day shifts was more modest: 2% higher on the second day, 7% higher on the third day, and 17% higher on the fourth day.

Six scheduling suggestions for injury avoidance
Based on the research, Liberty Mutual makes six suggestions for scheduling that will help reduce the risk of accident and injury:

  1. Schedule shifts starting in the morning, rather than afternoon or night shifts, if possible
  2. Limit consecutive night shifts to four. For day shifts, you can go to five or six without significantly increasing risk.
  3. Provide frequent rest breaks. For many kinds of work, hourly breaks are appropriate. However, more frequent breaks are recommended for highly repetitive or strenuous work.
  4. Schedule work so that all employees have at least two consecutive rest days. Saturday and/or Sunday should be one or both of the days off.
  5. Keep schedules regular and predictable.
  6. 6. Alternate weeks of overtime with weeks of normal time.

Not the end of the story
Liberty’s study covers types of shifts and overtime. But what about varying dangers within an eight-hour shift?

OSHA statistics identify times when workers are more likely to get injured.

  • Pre-shift: 0.3%
  • 0-2 hours: 19.5%
  • 3-4 hours: 26.6%
  • 5-6 hours: 20.1%
  • 6-8 hours: 21.8%
  • Overtime (+8 hours): 11.8%.

Second two hours
As these statistics show, the first, third and fourth quarter of a shift present about the same level of injuries.

But the second quarter of a shift, that is, the third and fourth hours, are actually the most dangerous.

Some possible reasons:

  • Workers have settled into their routine for the day and may not be as alert; and
  • The work site may start to get cluttered by then, as workers leave hazards for others, such as tools and electric cords for others to trip over.

Some suggestions:

  1. Take a look at your inspections during those second two hours. If you’re not out on the floor or work site, it may be a good idea to schedule some inspection time.
  2. Check housekeeping. Do workers keep their areas free of debris, tools and the like?
    Consider “housekeeping” breaks to give them a chance to do something different for a while, refreshing their concentration and allowing them to clear away any hazards.
  3. Warn workers of the increased dangers of those second and third hours. Remind supervisors to pay extra attention during those hours.

Click to View Comments

Leave a Reply


Request a Free Demo

We'd love to show you how this industry-leading training system can help you develop your team. Please fill out this quick form or give us a call at 877-792-2172 to schedule your one-on-one demo with a Rapid Learning Specialist.