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We now know that the "5-second rule" for dropped food is a myth (although some of us may still practice the 1-second rule, especially when no one's looking). But what about the carrot sticks or lettuce leaves that tumble from the colander into the sink? Surely the sink, which is regularly doused with soap and water, must be cleaner than the floor, which is regularly defiled by the feet we use to stand at the sink -- right?

Wrong, wrong, 500 times wrong, says Kelly Reynolds, Ph.D., an assistant professor of microbiology at the University of Arizona. While the floor may be crawling with 1,000 bacteria per square inch, the sink typically hosts around 500,000 bacteria per square inch -- and she's seen sinks that had millions more than that. "The sink is a ready source of bacteria just from washing off hands as well as food, which may carry fecal bacteria." The number of bacteria it takes to make us sick depends on the type, but Reynolds says that it takes between 100 and 1,000 bacteria to transmit salmonella, which is the most frequently reported cause of foodborne illness.

Reynolds says our kitchen sinks are often dirtier than the toilets of public bathrooms, which may be regularly scrubbed with powerful disinfectants. "If you dropped something in the toilet at the gas station, would you rinse it off and eat it? Use the same mentality for your sink."

[Next: What to do if you drop food in the sink]

 

Now, if you were about to boil those vegetables, you'll probably be fine, as most germs are obliterated by high cooking temperatures. But if salad dressing was the only thing you were planning to pour on those carrots, Reynolds advises a vigorous, no-joke rinse. "Rub the dropped produce with your hands under running water, as that dislodges the bacteria and rinses it down the drain." (Do the same thing if food falls on the floor.)

To reset your sink's bacteria count back to zero, Reynolds suggests regularly washing it with hot water and diluted bleach (she does this every day before preparing dinner). "You can also buy disinfectant sprays, but I find regular bleach to be cheaper and more effective." If you do this after meals, you can even toss in your dishtowels. Reynolds says that that if you can smell mold, the towel is basically crawling with germs.

Bottom line: The floor is by no means germ-free, but the kitchen sink is far worse. Prepare your salad over a disinfected countertop, instead.

 

Keep reading:

Is Your House Making You Sick?

Kill the Bacteria Lurking in Your Bathroom and Kitchen

How to Fight the Spread of Germs

Organizing in the Kitchen