You’ve probably heard lots of “rules of thumb” about workplace safety. But are they really true? This article will look at three of them.
Richard Sesak and Jerry Davis, two professors in the Department of Industrial and Systems Engineering at Auburn University in Alabama recently presented a session on safety truisms at the American Society of Safety Engineers Safety 2010 conference.
Using their research, let’s look at 3 safety rules of thumb and how true they really are.
- 90% of accidents are caused by unsafe human acts. 10% are caused by unsafe conditions.
- Indirect costs are 3-5 times the direct costs of accidents.
- If you must be within arms’ reach to hear normal conversation, you are exposed to noise at or above 90 decibels and need hearing protection.
Take a guess whether these truisms are true or false, and then find out by clicking here.
- 90% of accidents are caused by unsafe human acts. 10% are caused by unsafe conditions. Sesak and Davis say this is false. Their premise: Accidents are multi-factorial and can’t be simply divided into unsafe acts and unsafe mechanical or physical conditions. Take this example: An employee is late for a meeting. While he’s running through a hallway, he spills his coffee on the floor. He doesn’t bother to clean it up. Another worker, also late, rushes by, sees the coffee, and also doesn’t clean it up. A third worker, also rushing, doesn’t see the spilled coffee, slips and breaks her hip. This example has human and physical causes. Sesak and Davis say both unsafe actions and unsafe conditions are present in most accidents scenarios.
- Indirect costs are 3-5 times the direct costs of accidents. This one falls somewhere in between true and false. The two researchers say there is value in pointing out the indirect costs (replacing workers, paying overtime, loss of productivity, training, etc.) when an employee is injured. However, stating that the exact ratio is always 3-5 times isn’t correct. For example: Let’s say a worker receives a cut which can be treated with a simple bandage. The cost of treatment is quite low. However, the indirect costs of lost productivity would likely be much more than just 5 times the cost of the bandage. In more severe cases, it’s possible for the indirect costs to be closer to the direct costs themselves.
- If you must be within arms’ reach to hear normal conversation, you are exposed to noise at or above 90 decibels and need hearing protection. Sesak and Davis says there research shows this one is true. They created noise at 90 decibels and measured their own hearing zones. At 90 db, they had to come within arm’s length of each other not just to hear that the other person was talking but to understand what was being said.
The two researchers conclude that some rules of thumb can be useful when employed in the safety world. But others can be misleading or even counterproductive.
What do you think of their research? Do you have a favorite alleged safety rule of thumb that you’ve found to be false? Let us know about it in the Comments Box below.