We’ve all been there. You make a sandwich or a snack that you can’t wait to eat. Then you turn around and accidentally knock it to the floor. You’ve invested so much, and you’re eyeing that food, wondering whether the five second rule applies. But is this so-called rule really scientifically proven, or just another urban myth that could turn harmful if believed to be true? We get into the merits and more about food, the floor, and the scientific process of the five second rule in kitchens that might just have dirtier floors than a family diner in New York City.
So, can you trust the five second rule or not? Read on to find out!

food fallen on ground

The five second myth is essentially saying that the less time food spends on the floor, the less time there is for germs and bacteria to contaminate it. Of course, the contamination rate may also depend on how clean or dirty the floor is and how many bacteria can make it from floor to food. A very dirty floor may be a good contender for a zero second rule where the food goes into the trash. But is there really such a rule, and where did it come from?

The five second rule may have originated from beloved chef Julia Child. Child did inadvertently flip a potato pancake onto the stovetop on one of her shows and slipped back into the pan, saying that small slip ups in the kitchen were permissible and if no one’s in the kitchen cooking with you, no one will ever know! However, a stove top is significantly cleaner than the kitchen floor. Whether this was the origin of the rule or it is simply based on accumulated years of human experience where cleaning the food and making the most of it was more valuable than simply throwing the food away.

A Clemson University lab did a study published in the Journal of Applied Microbiology that studied the five second rule on a scientific scale. They measured whether the length of time food comes into contact with a contaminated service had an affect on the amount of bacteria that made it onto the food.

To do so, they inoculated different surfaces with Salmonella and then placed food on it for either five, thirty, or sixty seconds and 2,4,8, and 24 hours. This was done on tile, carpet, and wood. The bacteria levels were then measured. The end result was that the bacteria transferred was more dependent on how dirty or covered with bacteria than how much time was spent on the surface. Surface did make a difference, with carpet having less than 1% of bacteria transferring, as opposed to 48% to 70% of bacteria transferring for tile and wood surfaces.

So is the five second rule valid? Not anymore. There are a lot of bacteria and germs swimming around everywhere, and even if there’s a low amount of bacteria that transfer over to your food, eating it could still make you sick. That’s all due to the small amount of cells required to be in your system to cause illness or even death. Ten cells of E.coli are all it takes to make someone sick. Bacteria and protective biofilms lurk on many surfaces and objects, and if you’re not a regular cleaner, you might want to throw any food you drop straight into the trash.

The moral of the story? Use the five second rule at your own risk. You might get lucky… or you might not. Hopefully after reading this article, you’ll reconsider brushing off that muffin and just ditch it. Who needs the hassle?