When food falls on the floor, it’s always a judgment call as to whether that food goes into your mouth or into the trash. And many of us, when making that call, defer to the so-called “five-second rule” — that long-standing and widely accepted notion that if food spends five seconds or less on the floor it hasn’t had enough time to be contaminated by whatever bacteria is on the floor. But is the five-second rule based on any actual facts, or is it just a myth that we perpetuate every time we let our kids pick up and keep sucking on that lollipop they dropped?
Turns out, scientific research on the topic has been pretty limited … until now, that is. A team of researchers at Rutgers University’s School of Environmental and Biological Sciences put a variety of foods — watermelon, bread, bread with butter, and gummy candy — through their paces. They dropped them onto four different surfaces — carpet, stainless steel, ceramic tile and wood — and left them for less than one second, five seconds, 30 seconds and 300 seconds. All of the 128 possible scenarios were repeated 20 times; in the end, the researchers had a total of 2,560 data points to analyze. Read more