‘Five Second Rule’ is False. Bacteria takes less than a second to contaminate food

five-second-ruleWhile a common misconception regarding the ‘five-second rule’ is still very prevalent in the community, there isn’t any scientific evidence that proves that it actually works. A lot of people have no inhibitions when it comes to picking up and eating food that they have dropped on the ground as long as they’re able to pick it up and eat it under five seconds. A new study suggests that people should not be doing such a thing as it has no scientific evidence supporting such an idea.

So, is food actually safe to eat once you’ve dropped it on the ground? According to researchers of the new study, it probably isn’t. The current study tested the five-second rule. The results from the study showed researchers from Rutgers University in New Brunswick, N.J., that the rule didn’t work due to bacteria contamination taking less than a second to occur.

The lead researcher, Donald Schaffner, who is a professor and extension specialist in food science, said that the five-second rule is actually a very oversimplified concept that tries to explain what happens to food when bacteria contaminates it. People should know that bacteria contaminates in an instant. The current study was published in Applied and Environmental Microbiology.


During the research scientists dropped different food items. All of the selected food items had different textures such as bread, gummy candy, and watermelon. They were dropped on various surfaces that included stainless steel, wood, carpeting, and tile. All of the surfaces were contaminated (for various lengths of time) with salmonella-like bacteria known as Enterobacter aerogenes. All of the surfaces were allowed to become completely dry before the food was dropped on them.


The transfer of bacteria on each food surface was recorded after letting it sit for one second, 5 seconds, 30 seconds, and even 300 seconds. A total of 128 different scenarios were assessed twenty times by researchers. The total measurements recorded during the study were 2,560. The results showed that if the surface was dirty and had moisture then the spread of germs was even worse. However, regardless of the nature of the surface contamination of food was able to occur in less than a second. It was also noted that if the food was wet then bacteria was swifter in contaminating it. The results indicated that moisture played a key role in enhancing the rate of food contamination. This is because of the fact that bacteria doesn’t have any legs. It makes use of moisture in order to move. That is why the risk of contamination increases due to food being wet.

According to the results, watermelon was the most contaminated food item after it was dropped. On the other hand gummy candy was found to be the least contaminated. The researchers suggested that this was because watermelon is moist compared to gummy candy. Furthermore, food items dropped on surfaces such as carpets were found to be less contaminated than the ones that were dropped on stainless steel and tile. The food items that were dropped on wood showed different levels of contamination. This led to the assumption that the topography of a surface also played a role in rate of food contamination.

Researchers suggest that people should avoid eating food they drop on the ground.

Category: News

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Article by: Douglas Norman

Douglas writes all the latest health news for BodyFatLoss. He is very diligent about finding all the facts and sources of any new health and fitness findings.