Is There Any Truth to The 5-Second Rule?
by Michelle McLain


Applying the five-second rule will not actually decrease the risk of food contamination, according to a recent study. Yet knowing this information will not change anybody’s mind: people will continue to eat off the floor.
About two weeks ago, it was Super Bowl Sunday. The number one snack served? Chips and guacamole. But just how many of those chips were dropped, picked up off the floor, and eaten? If you are unfamiliar with the five-second rule, just ask any little kid. Or better yet, watch when a child drops part of a cookie on the ground. Hollering, “It’s still good! It’s the five-second rule!” he will proudly plunge the cookie piece in his mouth.But really, how dirty is that cookie?

In 2003, Jillian Clarke, a high school senior interning at the University of Illinois, discovered the reality behind the five-second rule. She found that there were very few microorganisms on the floors of the labs, halls and dormitories of the university.

Meredith Agle, a doctoral candidate supervising her research, said, “I think the floors were so clean, from a microbiological point of view, because floors are dry, and most pathogens ― like salmonella, listeria, or E. coli ― can’t survive without moisture.”

In Clarke’s study, she placed cookies and gummy bears on sterilized floors later covered with E. coli. The results? The E. coli traveled from the floor to the food in less than five seconds.

Clarke also discovered that just a little over half of men and about 70 percent of women have heard of the five-second rule. Plus, women are more likely to implement the rule than men.

In 2004, Harvard awarded the Ig Nobel prize to Clarke for her discoveries. The Ig Nobel prize recognizes “research that first makes you laugh, then makes you think.”

With handy knowledge that eating food off the ground is definitely a risky health practice, it would seem that the myth would die. Even MythBusters, a popular show on the Discovery Channel, debunked the idea that food is okay to eat if it’s only on the floor for five seconds.

According to their study, the time that a piece of food spends on the ground does not determine the eligibility for consumption. Time spent on the ground is not like marinating a piece of meat.

Have you ever heard any one change the “five-second rule” to the “ten-second rule”? Or better yet, have you ever seen someone scramble underneath a table to retrieve a Skittle―so then the “rule” gets changed to the “226-second rule”?

Good news for those who rely on the 226-second rule: you are no worse off than those who rely strictly on the five-second rule.

The most important things to consider before picking up a piece of food? Location, consistency, and value.

Depending on where the food drops, you may or may not want to plop that Skittle into your mouth. According to University of Arizona’s Charles Gerba, on average, an office desk contains 400 times more bacteria than a toilet. The kitchen is the largest germ-playground, notes the Journal of Applied Microbiology. Wet sponges and kitchen counter tops house billions of bacteria.

People generally follow the consistency rule, if sticky or wet food drops on the floor, don’t pick it up. Not even children will likely pick up sticky food. “I would never eat a pickle,” says Anaiah Grissom, 9, “not even after one second.” But the ideology is not just a myth. Sticky food really is more likely to soak up more bacteria than dry foods.

Remember that wiping a fallen treat will not disinfect, according to Web MD. If you decide to eat something that drops on the ground, the only way to truly clean your food is by killing the bacteria. Antibacterial washes or boiling the food are your best bet, but sometimes those options are not always available.

The last thing to consider before throwing that fallen chip back into your mouth is the value. It’s basic economics. Weigh your costs and benefits. To a child, value is measured by appeal: the tastier, the more likely a kid is to pick up the food. On the MVP list of food includes candies, chips, and cookies. Toss out the celery, cauliflower, and broccoli. But cake won’t pass the test. Why? It’s sticky! Of course, for adults, the measure of value is often placed on the monetary cost. If you drop that fillet mignon or halibut on the ground, are you really going to throw it in the trash?

Following the five-second rule requires an acute appreciation of risk. Knowing that the “rule” is a myth will hardly stop people from snacking off the ground. Kids realize that they are playing with germs, and perhaps that is part of the fun. But before you snatch a piece of candy off the ground, remember that is already dirty. And before you smack your hand in a vain attempt to remove germs, accept that you are not really disinfecting your food. And just before you snack on your delicious treat, always shout, “Five-Second Rule!”


  1. Awesome article! I’ve been saying this for years. Another great job, Michelle.

  2. enlightened in Canada

    A well written and researched article.

    Bravo !!

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