At least 50% of U.S. adults have eaten food off the floor. That’s according to a 2017 Harris Poll. Many people use the five-second rule. The rule says that fallen food is safe to eat if it has been on the floor for less than five seconds. Can people really use the five-second rule to save a dropped sandwich? Or should they toss it and make a fresh one?
Donald Schaffner is a professor of food science. He teaches at Rutgers University, in New Jersey. His study shows that the five-second rule should not always be used. In his 2016 report, he says it’s not wise to eat dropped wet food. The wet food soaks up bacteria as soon as it falls. “Bacteria don’t have legs, they move with the moisture,” Schaffner says. The wetter the food is, the more bacteria it soaks up.
Anthony Hilton studied the five-second rule too. He is a professor at Aston University’s School of Life and Health Sciences, in Birmingham, England. Hilton found that a dry food on the floor collects fewer bacteria than a wet food. Hilton also found that carpeted floors pass fewer bacteria than tile or wood floors. Still, one should be careful. “Food that is on the floor is never entirely risk-free to eat,” he says. “But if you drop a dry food in your house, it’s usually okay if you pick it up very quickly. Most clean homes don’t have bad bacteria.”
Should you eat food that was dropped on the kitchen counter? Dr. Steven Dowshen is a pediatrician. He is connected to Nemours/Alfred I. duPont Hospital for Children, in Wilmington, Delaware. He says that floors are not the only place that can make food unsafe to eat. “Kitchen counters can contain more-harmful bacteria,” Dowshen told TFK. This is because raw foods sometimes have bad bacteria called salmonella. These raw foods can be on kitchen counters. “If people eat food off a surface that has salmonella, they can get very sick,” says Dowshen.
With the five-second rule, the type of food and the place where it falls matter. So perhaps use this rule instead: When in doubt, throw it out.