It's still best to keep your food on your plate
Research at the U.K.’s Aston University has confirmed the old adage that food dropped on the floor for five seconds is clean—or at least it’s less likely to be dirty than if it sits there.
To test out the rule, students dropped toast, pasta, biscuits, and candy onto a floor that had been exposed to common bacteria and measured how much of the bacteria transferred when it was left on the surface for durations ranging from three to 30 seconds.
The results found that food left on the floor for less time does indeed get exposed to less bacteria. But more importantly, the texture of the floor that food is dropped on to is the most significant factor in how much bacteria is transferred.
Carpet is actually the cleanest surface to drop food onto, contrary to its connotations as a fibrous home for germs. It carries “the lowest risk of bacterial transfer onto dropped food,” Professor Anthony Hilton explains. Laminate and tiled floors are the worst offenders for dropped food infection.
That said, we’re not taking any chances.