Nugget of Knowledge: Five-second rule


YOUNGSTOWN, Ohio (WYTV) – Can we really protect ourselves from germs by snapping up our fallen snacks within five seconds?

Scientists at Rutgers University have tested the rule and say the answer is “…sort of.”

The rules says that food you drop on the floor is still safe to eat as long as you pick it up within five seconds. We’re not sure where that came from.

The scientists dropped four foods (watermelon, bread, bread with butter and strawberry gummies) on four different floors (stainless steel, ceramic tile, wood and indoor/outdoor carpet) for one, five, 30, and 300 seconds. Then, they looked for bacteria.

The longer the food samples sat on the ground, the more bacteria they attracted. Bacteria got on all of the samples in a second.

But what’s really important is not time but the type of food.

Bacteria love water. They swarmed the wet watermelon quickly.

The other factor is the floor itself.

Tile and stainless steel were gross, while carpet was relatively clean.

Within five seconds, the moist foods on started showing signs of E. coli or Staphylococcus aureus.

When it came to carpet, the food could rest for up to 30 seconds without any microbes showing up.

And dry foods, such as cookies or pretzels, could sit on any type of floor for up to 30 seconds before bacteria swarmed all over it.

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