Sci-Tech

Don't be a fool for the five-second rule

According to new research, the five-second rule is a load of hooey and you probably shouldn't eat the floor pie.

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Tamorlan, CC BY 3.0

The dread and sorrow as a delicious snack tumbles unceremoniously from our hands and onto the floor is a feeling that every human can relate to. Our salvation in such times is often the five-second rule: If it's on the ground for less than five seconds, it's still safe to eat. Well, no longer. That fallen morsel may still be unsafe for consumption, according to new research out of Rutgers University.

"The popular notion of the 'five-second rule' is that food dropped on the floor, but picked up quickly, is safe to eat because bacteria need time to transfer," said study leader Donald Schaffner. "[This] is a significant oversimplification of what actually happens when bacteria transfer from a surface to food. Bacteria can contaminate instantaneously."

That "can" is key. The team prepared a variety of surfaces with bacteria, dropped foods onto the surface and measured bacteria rates at 1, 5, 30 and 300 seconds. They conducted, overall, 2,560 tests.

Moister foods transfer bacteria more quickly than dry foods, and hard surfaces such as tile and steel transfer more quickly than carpet. Wood's transfer rate is variable -- it's all dependent on the topography of both surface and food. But, while longer contact results in more bacteria transfer, there's no avoiding it entirely. You can read the full study online.

Mind you, if it hasn't killed you yet, it's probably not likely to; not to mention there's bacteria everywhere, not just the floor.