Is the Five Second Rule real?

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Is this result not intuitively obvious? The five-second rule is a joke, guys.


Guys, you’ve completely failed to disprove the five-second-rule.

If I may cite the venerable Wikipedia:

The five-second rule states that food dropped on the ground will not be significantly contaminated with bacteria if it is picked up within five seconds of being dropped

Clearly the rule defines a period of time less than five seconds.

By starting the experiment at five seconds, these so-called “scientists” were p-hacking the results by picking conditions already outside the rule’s bounds.


The real five-second rules are “how long it takes before your dog gets something you dropped” and “can you pick it up and get rid of it before your kid eats it?”


I imagine this is due to amount of actual contact between the food and the surface, yes? With carpet, it’s only touching certain parts of the carpet whereas it’s going to land flat splat on tile or wood, and make much more contact with the surface. Plus, bacteria can travel down into the carpet itself, probably not so much with tile/wood depending on how it’s treated. Having said that, I think it’s WAY more likely that food is going to pick up random bits of loose dirt and debris (or in my house, my wife’s constantly shedding hair) that you don’t notice day to day on a carpet (depending on its colour/weave), but that would immediately stand out on a tile or wood floor.


It seems like if your floors are teeming with salmonella bacteria that you’ve probably got lots of other problems.


Oddly enough, this was the first title for the Public Enemy song, but was changed to be more “street”.


Yeah, but . . . bologna? I’ve always thought the five-second rule was for chips and cookies and such, not something ■■■■■ that is going to have all kinds of crud stuck to it when you pick it up.


This is basically indistinguishable from the Mythbusters result like 8 years ago.


Mythbusters explored this issue and found that it depended more on how wet the surface was than how long the thing sat there. This squared with my intuition on the subject, so I accept the results as scientific proof. Bacteria can’t jump. They need a medium to travel through or occupy that can be transferred. Also, if your immune system is healthy it will take care of insignificant contact. (tautological, yes) If you think about the contaminated lettuce it is a growth medium that has time to develop a significant amount of bacteria before consumption brings it into your system.


Americans eat garbage everyday, the “five second rule” ended a long time ago.

PS. In the Third World it’s the “Five Day Rule”.


Hear, hear!

I wonder what would have been the result if they had swabbed the clean dishes with salmonella, or maybe the experimenter’s hands! Or waited a few hours first, then tried it. Y’know, more realistic tests.

Years ago, I read about a ‘5-second rule’ experiment that was tried on true linoleum flooring on a university campus - where the floor wasn’t deliberately contaminated first. They couldn’t get an infected sample. The linseed oil in the floor kept it fairly sterile.

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Yea, but the 30 and 60 second rules are completely blown.

The same experiment was the basis for the pilot of the short-lived Food Network comedy science program “Food Detectives”:

The five second rule is real

Food hits the ground in most places it comes in contact with a small amount of bacteria. If you let it sit for a day, either on the floor or in a lab on a dish the bacteria will grow to levels that will have health effects.

But if you take the food off the floor and put it in your mouth it is then exposed to the antibiotic properties of saliva and shortly after that, the acids in the stomach and the small sample of bacteria is dead.

There are two things you really don’t want to eat in this regard. Large colonies of bacteria or mold that your defenses can’t kill off or some rather rare bacteria or parasites that can make you sick in small amounts. So unless the food gets covered in dirt and dust the 5 second rule generally holds true.

People are eating out of dumpsters and surviving people!!

I hate when amateur science gets passes off as fun science reporting, glad to see this article straightening that out. Now lets move on to how bad it is to not wash you hands after you pee.

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No no no I know that song you trickster!

Bacteria can’t jump.[citation needed]

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I had always assumed that bologna was teeming with all manner of disagreeable flotsam whether or not it touched a floor.


You mean 9-11 is a hoax?


In a highly scientific study that was performed in my living room, my spouse dropped a piece of pizza on the carpet, picked it up and ate it, then reported feeling especially energetic the following day. My conclusion is this: not only is the 5-second rule real, but eating carpet pizza will increase your health and well-being.

You are welcome.