Aaron E. Carroll, a professor of pediatrics at Indiana University School of Medicine, published an article last weekend debunking the debunkers who say that the five-second rule is bunk. The opponents of this time-tested rule claim that food that falls on the floor is dangerous no matter how fast you pick it up. They claim, essentially, that bacteria don’t wait around for five seconds before jumping onto the food and digging in. Carroll says, however, that his kitchen floor isn’t that dirty — or at least not as dirty as many other surfaces that we don’t consider dangerous. He cites the research of Charles Gerba, a professor at the University of Arizona, that kitchen floors are likely to harbor, on average, about 2.75 colonies per square inch of coliform bacteria, but the refrigerator handle and kitchen counter have, respectively, 5.37 and 5.75 colonies per square inch. (FYI, toilet seats have 0.68 and flush handles have 34.65.)
If you’d ever eat food with your hands after touching a kitchen sponge, which can easily have up to 20 million colonies per square inch, you might have a seat (on the floor) and chow down.