Random Facts on Food: The Five Second Rule

MYTH: It safe to follow a 5-second rule for dropped foods.

FACT: It is not even safe to follow a 1-second rule. The transfer of bacteria from a contaminated surface to food is almost instantaneous—or, at the very least, quicker than reflexes. In one study (Clemson University), the experimenters contaminated several surfaces (ceramic tile, wood flooring, and carpet) with Salmonella. They then dropped pieces of bologna and slices of bread on the surfaces for as little as 5 seconds and as long as 60 seconds. After just 5 seconds, both food types had already picked up as many as 1,800 bacteria (more bad bugs adhered to the moisture-rich bologna than the bread); after a full minute, it was up to 10 times that amount.