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The 5-Second Rule

January 19, 2012

How Much Germ Knowledge do YOU Have?

Imagine this. A child drops an apple slice on the floor of the playroom, stares at it with a look of terror, but then quickly picks it up and eats it. This is all too common. What gave this child the confidence to pick up the “dirty” apple slice? The infamous 5-second rule. When the apple slice hit the floor, the child quietly sat there and counted to five to make sure the apple slice was safe to pick up. If it had been on the ground for longer than five seconds, the child probably would have turned away and grabbed another slice out of their snack bag.

What exactly is the 5-second rule?

In case you haven’t heard of it, it says that food is still OK to eat if it is picked up off the floor in 5 seconds or less.

Can the 5-second rule be trusted? Not exactly. Germs are instantly transferred upon contact with a dirty surface. It doesn’t matter whether the food item has been on the ground for 5 seconds or 5 minutes; it’s still going to be germy. In a scientific study of the 5-second rule at Clemson University, students tested the 5-second rule. In their experiment, they tested the ability of bologna and bread to pick up bacteria when dropped on various surfaces, including countertops and the floor. They concluded that bacteria is instantly transferred from surface to food, proving that the 5-second rule is not a safe guide when assessing food that has been dropped on the floor.

Next time you consider the 5-second rule, remember this:

  • A clean looking floor is not always clean. Some bacteria can survive on surfaces for very long periods of time, even though you cannot see them with a naked eye.
  • Some surfaces are dirtier than others. For example, food dropped on the sidewalk is most likely cleaner than food dropped on the kitchen floor.
  • The type of food that is dropped will help you to decide whether or not to throw it out. Any food with a wet or sticky surface, such as an apple slice, is likely to pick up more bacteria than food with a dry surface.
We have all been guilty of the 5-second rule.

What do you think? Is there such a thing as being too cautious? Is the 5-second a safe guide to follow?