It’s a rumor that has circulated in school cafeterias around the world for years. The so-called “5-second rule” is the idea that it’s safe to eat food dropped on the floor if it’s picked up within 5 seconds. The true origin of the 5-second rule is a mystery. Some people believe it originated with tyrant Ghengis Khan, who demanded people still eat food that fell on the floor during his banquets. Others attribute it to Julia Child’s cooking show in the 1960s, when she picked up a pancake that fell on the stove and told viewers it was still okay to eat. So, is there any truth to this rule? Scientists decided to find out by dropping a petri dish onto a surface for varying lengths of time, ranging from one second to one minute. They then placed the samples in a refrigerator to cool until the results became clear. Disgustingly, the petri dish had hundreds of colonies of bacteria after just 5 seconds on the surface. The dishes that had been dropped for 5-20 seconds looked very similar, but things really began to ramp up from there. After 30 seconds, the dish had grown a huge colony. So, the bottom line: Whether it’s one second or 60 seconds, food that hits the floor should be immediately discarded.
