The five-second rule — the idea that you can safely eat fallen food if you pick it up within five seconds — is as controversial as it is popular. While technically it's not really true, it works because your kitchen floor is pretty clean.
As the video above explains, the five-second rule is technically untrue. More specifically, there isn't really a set period of time in which foods can't pick up bacteria. Sitting on the floor for one second is as bad as sitting on the floor for five.
However, you've likely picked up food off the floor within five seconds and been fine. What gives? Well, as the video goes on to explain, your kitchen floor is likely one of the cleaner surfaces in your kitchen. You can eat food off it because you clean it. A study by the International Journal of Environmental Health Research found that surfaces like the refrigerator handle and even the kitchen counter contained more bacteria colonies per square centimetre than the kitchen floor.
You also touch a lot of objects that are way dirtier than your kitchen floor every day. Your phone, wallet, purse and money all get washed less often and touched more frequently than your kitchen floor. They have a much higher potential for carrying bacteria, yet no one thinks twice about grabbing their smartphone in the middle of a meal. Well, at least not for health reasons.
Of course, this depends a lot on how much you clean your floor and what kinds of foods you drop. However, if you clean your kitchen floor, but don't clean the things you touch often like faucet or door handles, then you're not putting yourself at extra risk just by eating food that was on the floor for a couple seconds. So don't worry. You can still eat food you dropped. Just make sure that you're cleaning your floor (and all the other surfaces in your kitchen) once in a while.
The 5 Second Rule: It's Still Not a Thing. [Healthcare Triage]