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Here's why we need to wash our hands for 20 seconds

And here's why something as simple as soap and water can kill the deadly virus

ST. LOUIS — One of the top things we’re told to do to protect ourselves from the coronavirus is to wash our hands frequently, thoroughly and for 20 seconds with soap and warm water.

But how exactly does soap fight COVID-19? And why is the 20-second rule so important?

Here’s why…

If you take a really close look at soap (like, under a microscope) you’ll see a molecule. One side loves water. The other side loves fat and hates water.

Take soap and water and put it up against oil, for example, and the soap molecules will go to work. The water-loving side goes toward the water, and the fat-loving side goes toward the oil. It’s why soap does such a good job cleaning gross, grimy dishes.

RELATED: Elmo, Cookie Monster enlisted to teach kids about hand washing

As far as the coronavirus is concerned, the outer layer of the virus has a weakness: the fat-loving side of the soap molecule.

The outer layer of COVID-19 consists of the tubes that are seen sticking out from the virus. Scientists call it a membrane of oily lipid molecules.

But that membrane is no match for soap.

Each soap molecule pries the membrane apart, exposing the inside of the virus to water, which dissolves in water.

Soap molecules then wrap around the bad stuff and when you add in more water, it all washes away.

So, why 20 seconds?

Take a look at your hands. Notice all those lines? Viruses love to get in those. So, more soap time means more time to clean those cracks and grooves.

Hand sanitizer will do the trick, too, thanks in no small part to alcohol. The alcohol denatures – or, destroys – the virus.

The key part is to make sure you have at lest 60% alcohol in the sanitizer. So that vodka in the liquor cabinet probably won’t work.

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