Does the 5 second rule count?

You may have done this a few time in your life without having any harmful effect to yourself but just beware that the 5 second rule doesn't count. Bacteria DOES transfer to your dropped food WITHIN 5 seconds. In a 2007 study published in the Journal of Applied Microbiology, researchers at Clemson University doused floor surfaces (tile, wood and carpet) with Salmonella and then dropped bologna and bread on them for 5, 30 or 60 seconds. Within five seconds, the food picked up 150 to 8,000 bacteria (the least from carpet, the most from tiles). What’s more, they found that bacteria can live on dry surfaces for several weeks at levels high enough to quickly transfer to food. According to the lead author, Paul Dawson, Ph.D., "while the bacteria found on most surfaces are harmless, food dropped on surfaces contaminated with pathogens will pick up those bacteria immediately.”

So dropping your food on the kitchen floor where you probably mop once a week is not that bad but just beware (and definitely as its now BBQ season and you be out and about more often at different venues), that the next time you drop your food/ snack, best to leave it on the floor or throw it away. 

 Dr Steven Dowshen shares his point of view:

"No, it's never a good idea to eat food that has been dropped. The 5-second rule is just wishful thinking — bacteria can attach to food as soon as it hits the floor. And foods with wet surfaces, like an apple slice, pick up bacteria even more easily than, say, a cookie. The longer the food is on the floor, the more bacteria it will accumulate. But even food that's picked up quickly can be contaminated if conditions are right. While visibly dirty floors are obvious hazards, those that look clean also can harbor bacteria. Some germs can survive on floors for a long time, and without a powerful microscope it's impossible to see them.

Bottom line: Summer is coming up and bacteria is more likely to be prevalent due to heat. Use common sense. Occasionally eating food that was briefly on the floor is not likely to make you sick. But it depends on what you drop and where. There’s a big difference between picking up a cracker from a just-cleaned dry kitchen floor (probably safe) versus the floor by the cat litter box (not). Or between a reasonably clean living room carpet (probably okay, though a little fuzzy) and a public bathroom (obviously not). On the other hand, since it’s hard to judge just how clean a floor is—it may look spotless but still harbour bacteria—you shouldn’t make eating off it a habit. And if you’re immune-compromised or in frail health, it’s best to follow the “zero-second” rule. Keep in mind, too, that microbes are not just on floors. In fact, kitchen counters can be even more contaminated than the floor.

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