Five Second Rule Fails the Test

Time is up for the ‘five-second rule’. The so-called rule states that if you pick up food that is dropped within five seconds, it is free of germs and safe to eat. Many people follow this principle – especially when it is their favourite food.

Bacteria, however, are faster than we are. Researchers at Rutgers University decided to test the rule and found that food is contaminated almost immediately when it touches the floor. They tested four different foods (watermelon, bread, bread and butter, and gummy candy) on four types of floor surfaces (stainless steel, ceramic tile, wood, and carpet). The research showed that the watermelon had the most contamination and candy had the least.

Floor surfaces also affected the results with a carpet having the lowest rate of germ transfer and wood surfaces having the most variability. “Bacteria don’t have legs, they move with the moisture, and the wetter the food, the higher the risk of transfer. Also, longer food contact times usually result in the transfer of more bacteria from each surface to food,” said Donald Schaffner, professor and extension specialist in food science at Rutgers. The latest research confirms what experts previously believed. Basically, the less time food is on the floor, the fewer bacteria it will collect, but it will still gather germs. To be safer, you shouldn’t eat food that has touched the ground.