May 28, 2007

The Five Second Rule: Scientists Actually Investigate

Didn't you think it was a joke? The "five second rule" is something everyone laughs about when food drops to the floor. No one really believes that it's a real "rule," right?

For those of you who grew up in super-sanitary households and may have missed hearing about it, the "five second rule" goes like this: If you drop food on the floor, and you pick it up within five seconds, you can eat it. Any longer and the food is contaminated and you have to throw it out.

In real life most people create their own rules. The most hygienic say: you've got to be kidding. There's no way I'd ever, ever, eat food that touched the floor. People walk there. People whose shoes have been on sidewalks where dogs might have... You get the idea. You know if you're one of these people.

Others are more... flexible. There are many variables to consider. How recently was the floor cleaned? How sticky or permeable is the food item? (An M&M, for example, gets more floor time than a peanut, which gets more than cheese, which gets more than a deviled egg. The cost of the item, the desire for the item, whether there's any more in the fridge, whether anyone is watching, whether the watcher is a family member or a guest... all these factor in along with how many seconds have passed.

For some reason, though Crabby is very concerned about healthy living generally, she is shockingly lax about dropped food. She is much more afraid of carcinogens than germs. She can't see anything bad down there on the kitchen floor, and as far as she's concerned, ignorance is bliss. If she got sick every now and then she might reform her ways, but she doesn't. So Crabby continues with her slovenly habits.

So what does recent research say about the five second rule?

Pretty much what we all expected. There's not a magic "five seconds," but a slice of bread or bologna left on the floor for a full minute has about ten times more bacteria than a slice left on the floor for five seconds. There's not a horribly dangerous level of bacteria on most kitchen floors, but you could, if unlucky, pick up enough salmonella to make you sick--even in five seconds.

"What doesn't kill you makes you stronger," someone once told Crabby. She should be very strong now indeed.


  1. Sadie eats all kind of things off the floor. She is so uncivilized. I, on the other hand, only eat things off the floor if Karen is in one of her moods and isn't willing to pull out the good china. Then I make a decision if it's worth it or not. Things like chicken or tuna or-- yeah it's worth it. Otherwise, I leave it for Sadie.

    As for the other, you can tag me. I will play your game.

    -- P

  2. Penelope!
    A cat of your refinement should not have to eat off the floor like a greedy human.

    And thanks for playing meme games! They are not as fun as mouse games, as no one gets dismembered at the end, but we humans do the best we can for amusement. Instructions, such as they are, are in the previous post but feel free to ask if you have any further questions.

  3. They tested the five second rule on an episode of Mythbusters, too. I don't remember what their ultimate conclusion was, but they did find that wet foods get dirtier than dry foods.

    I've always been squeamish about eating anything that's been on the floor. I'd rather throw it away. :p

  4. Very smart, chicken girl!

    I'm just (a)lazy and (b)cheap.

    Does depend on the food and the floor, though.

    1. I am so with YOU, Crabby! Loved this one! Your blogs always make me laugh!

  5. If it falls on the floor and can be washed, then it gets washed before I eat it.
    If it's not a washable food,like say, a bit of soft butter, then it's off to the garbage.

    If we're out camping and bacon falls on the ground it is brushed off and consumed before I can give it any thought.

  6. Now this is my kind of study. Food - and the consumption of!

    I have never heard of this five second rule! I don't know if that's because it hasn't got to NZ or whether it's because I'm ignorant.

    My response would be - it all depends! - on my memory of that particular bit of floor's recent history - or an educated guess on it - and how much I want that item of food and, yes, I admit it, is anyone watching!

    So if a forkful of spinach drops on the floor where the dog threw up yesterday I won't touch it and anybody that does is a greedy, disgusting grub. If, on the other hand, it is the last cream filled apple donut on the planet and nobody is about and I was looking forward to it so much and ...

  7. It is hard to believe someone felt the need to investigate that saying, as if anyone really believed it!

    Love your site. I found it at Total Transformation. I figured that anything with the name "Crabby McSlacker" had to be interesting!

  8. It is hard to believe someone felt the need to investigate that saying, as if anyone really believed it!

    Love your site. I found it at Total Transformation. I figured that anything with the name "Crabby McSlacker" had to be interesting!

  9. Hi Leah!
    Yes, I am a total believer in the "camping exception" to all rules of hygiene. Not that I apply them all that rigorously when not camping, either.

    Dawn--I'm so with you, both on the spinach and the donut!

    Hi neil, and welcome! (And I'm glad I'm not the only one who ends up double posting when the first one won't go through).

    It is amazing the research that gets funded sometimes. Though it was an amusing enough premise that it probably got lots of publicity for them, which I believe may lead to more research $$ in the future. (Plus I have to admit, as someone who's been known to grab the stray M&M off the floor, that it was interesting to read about it).

  10. Way I figure it is there ain't anything on my floor any worse than they put in hotdogs and Spam and since I like both of those my gut says eat it up.

    Unless yoo happen to be dining in a barn then I strongly suggest you let the dogs fight over the scraps.

  11. Re. camping - yes, there is "clean" and there is "camping clean." Two completely different things.

  12. Hi Travis (& Neil),

    I think we're developing a good set of non-kitchen corallaries here. Camping: Five seconds at least. Barns: Nope, the dogs get it.

  13. hmmm. I always remembered it as the 10 second rule.

    And somehow announcing it "10 second rule!" in front of people made it way less weird than if you just picked it up off the floor and ate it.

    I definately have an "ignorance is bliss" kind of attitude when it comes to the floor...until one of us gets sick. yecchh.

  14. Katieo,

    "And somehow announcing it "10 second rule!" in front of people made it way less weird than if you just picked it up off the floor and ate it."

    I think you just hit on the whole reason someone invented the rule--and the reason a lot of us still cling to it, even if we don't believe it. Otherwise, we look like total pigs.

    Very clever!

  15. If I don't see hair or dirt on it, I am okay with eating

  16. Depending on what it is, which floor, and whether it's covered with dog hair determines if the food can be eaten! LOL

    For those of us who do use the 5 second rule, we probably have stronger immune systems because of our actions!!

    I try to keep a clean house, but I'm not nutty about it. I don't use disinfecting hand soap, etc. So far no one's gotten sick from my house, and my kids and I are rarely sick.

    I've had food poisoning, twice. Not just the stomach is acting up kind, the I think I need to be in the hospital kind. Both times related to eating out. I guess if I ever got sick from my own house I'd be more careful! LOL

  17. Hi John--
    I too tend to respond to the visual rather than the invisible in evaluating what's safe to eat. Thanks for stopping by again.

    And Hi Cindy!
    I'm totally with you on the immune system thing. I think those of us who are a bit more flexible about germs actually build up the ability to fight off bad bacteria better than those who try to banish all the intruders from their lives.

    (And in our house it's cat hair rather than dog hair, but we just pick it off. Our cat is never sick, so how bad could her fur be?)

  18. Oh, how did I forget to comment on you blog today, Crabby? I read this post this morning and thought, "I like Crabby, she will eat off the floor like me." I think that will be my new criteria for friends. If they will eat something off the floor, they can come in. If they are too uptight, I'll just gross them out.

  19. Very informative! hehehe I'm so glad I'm not only one who has a "five second rule" -- though if I can see hairs stuck on it, even I'll toss it the trash.

  20. Hooray, Samantha and Lady Rose,

    You are my kind of people!

    Can Crabby admit that she has, on occasion, even plucked a cat hair or two off a dropped item and eaten it anyway? Bad, bad crab.

  21. We have no time limit at our house. If it comes up off of the floor in one piece with no dog hair on it, it's good to go.

  22. Hi one tough mama,
    Great blog you've got there. And I bet you've all got good healthy immune systems. I think of floor germs sort of like cheap bacteria vaccines--a little bit to strenghten you without outright killing you.

  23. That's why I keep trying to get my husband to take his shoes off in the house...

  24. Hi Andrea!
    Sorry I missed your comment earlier. We keep thinking we should go shoeless in our house too and even tried it for a few days, but found the on-ning and off-ing too tiresome. Which should make us less likely to eat off the floor, yet it doesn't somehow. Thanks for visiting, and you have a very cool blog & website!

  25. I'm glad to hear floors are clean enough to eat off of. Now I'd like to see the myth about walking barefoot in restaurants/public squashed. If the floor is good enough for food then the same for barefeet.

    ----John,society for barefoot living:


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