Is the 5 second rule fact or fiction?

Most people have heard of the 5 second rule: if a piece of food is dropped on the floor it is safe to eat so long as it isn't there for more than 5 seconds. Sometimes the time frame is changed to suit the situation and the persons desire to eat the droppings, it could be the 2 second rule or perhaps the 30 second rule if the morsel is really appetising.

The reality is that whether the food is safe to eat or not depends on many factors but as a rule it is safer not to eat the food. There have been numerous studies into the time that it takes for food to become contaminated and a number of factors have been identified which significantly alter the outcome. Surprisingly a kitchen or bathroom floor is more likely to contaminate food dropped on it than a footpath or sidewalk.

Factors affecting the speed at which food can become contaminated include:

• the porosity of the surface ( porous surfaces tend to harbour more bacteria)
• the texture of the surface ( rough surfaces are more difficult to clean but may allow less contact with the dropped food item)
• the level of moisture on the surface ( bacteria love a moist environment)
• the location ( kitchen floors generally have high levels of bacteria due to the regular presence of food particles whereas a bedroom floor would generally have little to sustain bacterial growth) 

There is no scientific evidence to support the 5 second rule and from a food safety perspective anything that touches the floor or ground should not be eaten.

The 5 second rule has been the subject of academic research by Clemson University which studied contamination levels resulting from contact with 5 different surface types. The television series 'Mythbusters' episode 39 also looked at the 5 second rule and found that the was little difference in the contamination levels occurring after 2 seconds and after 6 seconds. 

If you would like to know more about food safety and safe food handling the Australian Online College has two (2) courses available. Why not enrol in a safe food handling certificate course now? 

This page is about the 5 second rule, food safety and food safe handling.