The five-second rule, so-called due to the fact that it is jokingly presumed food that has fallen onto the floor or another dubiously-cleaned surface is safe to consume so long as it has been retrieved within five seconds of dropping, is a oft-repeated bit of food safety lore.
It seems pretty safe to presume few people take the five-second rule seriously as a guideline, but who hasn’t had that moment of “will I or won’t I?” after losing an irreplaceable sandwich half or a perfectly good Cadbury Creme Egg to the carpet?
It’s a well ingrained meme that the faster you pick up the food that has fallen (hence the “five-second” aspect of the rule), the less germy said food has become. And the idea is so pervasive that food and infection experts have addressed the five-second rule, saying that diners should be more pragmatic when it comes to what they place in their mouths and potential contamination — but that eating the occasional bit of food that has fallen afoul of the five-second rule probably won’t kill you.
You still should brush off the cat hair first, though, because ew. Jorge Parada, MD, MPH, FACP, FIDSA, is medical director of the infection prevention and control program at Loyola University Health System, and Parada confirmed that food becomes contaminated immediately when it hits the floor, adding that the real rule should be “when it doubt, throw it out.”
Medical Daily paraphrases Parada on the subject of proper judgment in relation to the five-second rule, and he explains that the type of food and the condition of the surface make a big difference:
“For example, Parada says, if you drop a hot dog on the floor, you might do well to wash it off. But even rinsing the hot dog may not remove all of the bacteria. And, he continues, if you drop an item, and 1,000 bacteria migrate to it, maybe you will be fine, since the average person requires 10,000 bacteria in order to become infected. But maybe your threshold – or that of a loved one – is lower.”
However, Parada also admits to not always “throwing it out” and sometimes exercising the five-second rule himself.