The 5 Second Rule

How Fast Can Germs Get On Your Food?

food on the floor
Is the 5 second rule really true?. Paul Thomas/The Image Bank/Getty Images

Nearly everyone has heard of the 5 second rule. If your food hits the floor but you pick it up within 5 seconds, it's safe to eat, right? It turns out a vast majority of us believe it too. Studies have shown about 90% of people admit to eating food that has fallen on the floor at some point. But is there really any truth to this old saying? 

Consider the Possibilities

Bacteria, viruses and other germs are everywhere - especially on the floor where people and animals walk frequently.

If you stop to think about the germs that could be waiting on the floor, the food you dropped may become a little less appetizing. But if you aren't thinking about that or you want to know the science behind the 5 second rule, it turns out researchers have actually studied it. 

There is some degree of truth to the 5 second rule. The less time food spends on the floor, the fewer germs it picks up. And as you may expect, dry, hard foods pick up fewer germs than wet foods. But that doesn't mean you are safe to eat all hard, dry foods that hit the floor. 

Studies have shown that even though food that spends less time on the floor picks up fewer germs, it still picks up some germs. And since germs are way too small to see, there is no one way to know if the few that ended up on your food are the kind that will make you sick or the kind that won't.

Good Germs vs. Bad Germs

Bacteria, viruses and other germs are everywhere in our world.

They are inside and outside of our bodies. Some of them exist without causing us any harm and others invade and make us sick. 

There is no way to know which germs are where and when one of them will make you sick. Cold and flu viruses could be anywhere. The influenza virus (which causes the flu) can live on surfaces for up to 8 hours.

Others - some that are much more dangerous - can live for days or even longer. 

Should You Risk It?

Everyone's immune system is different. Those with weak or compromised immune systems (such as people with chronic illness or autoimmune disorders and those undergoing cancer treatment) are more likely to get sick. Their bodies have a harder time providing protection against germs. If you fall into one of these categories - or you are just someone who gets sick a lot - you probably shouldn't risk eating anything that has fallen on the floor. 

Another thing to consider is that even if a floor looks clean, that doesn't mean it is. Germs are not visible and can be present on any surface. 

Imagine eating off the mop that you cleaned the floor with. Not very appetizing, right? Even if you (or someone else) cleans regularly, germs can still be present. In the end, everyone makes their own decisions about whether to believe in the "5 second rule". One of my favorite tips to keep in mind when it comes to food is: 
When in doubt, throw it out!


"The 5 Second Rule". Health Basics Jan 14. Teen Health. KidsHealth. The Nemours Foundation. 15 Sep 15.

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