Is the “Five-Second Rule” a Myth?

bacteriaHarold McGee, also known as the New York Times’ “Curious Cook,” has an article about a new paper from a Clemson University research group led by Paul Dawson on the validity of the “five-second rule” — the old adage that if you drop food on the floor but pick it up within five seconds, it’s okay to eat it. According to a 2003 survey conducted by Jillian Clarke (a high-school intern at the University of Illinois who later won an Ig Nobel Prize for her research), more than 50% of adult men and 70% of adult women knew of the five-second rule, and many said they followed it. Now the Clemson researchers have gathered data to assess its validity once and for all. The results? According to McGee:

On surfaces that had been contaminated eight hours earlier, slices of bologna and bread left for five seconds took up from 150 to 8,000 bacteria. Left for a full minute, slices collected about 10 times more than that from the tile and carpet, though a lower number from the wood.

A definitive answer! It works! Sort of! That is, there’s no guarantee that the 150 to 8,000 bacteria gained in those five seconds are safe for consumption. As such, McGee proposes that the rule be revised as follows:

If you drop a piece of food, pick it up quickly, take five seconds to recall that just a few bacteria can make you sick, then take a few more to think about where you dropped it and whether or not it’s worth eating.


In our house the 5-second rule is almost mandatory. If you don't pick up a piece of dropped food within five seconds, you'll lose the chance because one of the cats will be eating it. Sometimes even five seconds is too long.


Proving once again that there is no myth that Mythbusters has not already busted.

egretman the little pic of bacteria, BTW.


From what I can recall, I think that the Mythbusters showed that something moist (like a slice of bologna) was far more likely to pick up bacteria than something dry. And I've really never found the need to pick something that was slightly wet up off the floor and eat it, so I've never been affected one way or the other.


I'd like to make a correction to the post. It reads "more than 50% of adult men and 70% of adult women knew (...)", but clearly that should be: "more than 50% of adult *American* men and 70% of adult *American* women knew (...)"

In Sweden, this "rule" is unheard of, except that a few people may have heard about it from American sources. In those instances, I would expect 100% of Swedish adult men, and a slightly higher proportion of adult Swedish women, to laugh at the general silliness of the rule.


where is the guest blogger ?

in Canada we know of 5 second rule , right after the rule a little dirt never killed anyone ...........

question what about Bacteria in the air that lands on your food that never left the plate ?


My own rule is that in houses with pets, even 1 second is too long.


@Imsdal: You forgot to boast about how good Swedes are at statistics.

The five-second rule is purely psychological -- I don't think it comes as much of a surprise that it doesn't actually work. Really we're just looking for justification.

Think of it this way -- you just dropped food. The dropping will always be accidental, so you made a mistake. To recover you can either: a) toss the food (admitting your mistake and suffering a loss) or b) pick it up and eat it anyway (thereby simultaneously asserting a tough-guy stance regarding food safety and losing nothing due to your clumsiness).

Now, if you DO get sick, you'll feel even dumber for having made two mistakes out of one ... unless there were a rule of some kind, you know, perhaps that food is safe for five seconds or so when dropped...


oh...that five second rule...nevermind


I would rather like to know an infectious disease MD's guesstimate as to the odds of developing symptoms from floorbound food- not counting for children/elderly/immunocompromised eaters (I agree with InvisibleJ's tough guy stance)- I would also like to know an opinion on people who cover their food for transit- where I work, everyone (except me) covers their plates with saran wrap to walk the food from cafe to office- I say- what gives?- if the air was toxic, it would be more rational to hold your breath during the transit!?


egretman - Don't put too much faith in your MythBusting deities. They said a human couldn't catch an arrow in flight ... and they were WRONG.


Well sygyzy, I don't think they meant for you to catch it just anywhere in your body. I think they meant with your hands!


Be careful with dropped bacon.

A blackened and compressed amalgamation of dust, lint, animal hair, and years of never-been-mopped kitchen floor detritus can resemble a dropped piece of charred bacon when you are hungover and haven't yet put your glasses on.

Mmmm ... bacon, d'oh dropped it on the floor.
(5 sec. rule in play)
d'oh, that's not bacon.


Growing up on a farm, the 5 second rule was followed immediately by the 10 second rule in the event the 5 seconds didn't hold true. Having 2 children under the age of 3 we get a lot of cheerios on the floor. The first person to step on a cheerio each day is responsible for sweeping them up. Points are awarded for the farthest cheerio found in the house away from the kitchen. If we ever get another dog, I swear I am going to name him Roomba, after the iRobot floor sweep.

Indigo Starblaster

There's a great Chinese saying that I always fall back on when eating a piece of just-dropped food: "Big germs eat little germs."


I like cats.


@Indigo Starblaster : I love the Chinese saying

In Egypt no such rule exists. Generally if the floor is dry, the food is dry, most people would pick it up quickly and eat it.


we are doing a science fair project about does the 5 second rule exist. You site has helped us!

Ham Sandwitch!

im doing my science project on the five sec. rule

5 second rule is awesome


how can you test the five second rule considering i am only a high school student?