Posted by: momecology | September 24, 2009

Soap or Sanitizer? Just use some!

About once a year. I think that’s the right posting frequency. Don’t you?

It's too late for it to help me, but go on, don't hold back.....

It's too late for it to help me, but go on, don't hold back.....

Having spent the last week in bed, felled by the flu, I have had a certain amount of time (and reminders in the form of fever and surplus mucus!) to think about hand-washing (or the lack thereof). If you are living anywhere but on the Moon, you will have recently read at least one notice from someone officious — uuuuhhhhh, official that states you can reduce the spread of flu by “either washing your hands or using hand sanitizer” frequently. And to that, too late, I say amen. But I also say, Really? Either one? And there’s no difference?

As a matter of fact, soap and hand sanitizer work in completely different ways. One kicks all the hitchhikers off the bus, and the other one kills them, but leaves them in their seats. So which you choose to use could depend on whether you have a Tarantino-like personality. Or just if you have any water.

You don’t need me to tell you that in the course of daily life, your hands come in contact with what are commonly called Germs. (To a biologist, there is no such thing as Germs; there are a large variety of living things too small to see without the kind of magnification found in a microscope. But it’s tedious to list them all in every conversation where all you want to get across to your kids is that they must wash their hands even if they LOOK clean. Yes, NOW.  So: Germs.)  Germs stick to the oils produced by the skin on your hands. Thus when you touch your face (even though you’ve been told a million times not to, but the attraction of your fingers to your face is like that of the tides to the moon, inexxxxxxxxooooorrrrable) the germs get a ride right to your delectable, penetratable mucus membranes.

This is where the soap or hand sanitizer comes in. If you want to keep the germs hitching a ride on your hands from reaching their destination, you have to interrupt the trip, either by handwashing with soap, or rubbing in sanitizer. Allow me to ask you at this point: hasn’t it ever struck you as odd that you rinse off soap, but not hand-sanitizer? Why is that?

The difference is in the way each works. In your youth, you were told that soap “kills germs”. So was I. That, like the one about Santa, was a simplifying lie. (I know! Can you believe it? Santa! Not real!) As it turns out, what soap actually does is loosen the bonds that allow oil and dirt particles and their germ-jockeys to cling to your hands — then once they’re sliding around, without a firm hold on your skin, the water you run over your hands carries them right off. The process doesn’t actually kill the germs — it’s more like taking off their seatbelts, and then flooding the bus with the windows open. (This, in addition to the taste, is why it’s a bad idea to drink water you’ve washed with. Live germs still in there, folks.)

Hand sanitizer works differently. Hand sanitizer is mostly alcohol. Alcohol has many notable properties. In addition to making you feel woozily that perhaps it would be a good idea, after all, to have another baby, alcohol denatures proteins. “Denature” is a good term – it means to take a molecule of protein in its natural state and twist the bejesus out of it, until it is quite incapable of acting like the protein it was born to be.

What the hell am I talking about? An example:

egg au natural

egg proteins, au natural

egg de-natured

egg proteins, de-natured (in this case, by heat)

The proteins in the first picture are living, functional, ready to make a fluffy baby chick. The proteins in the second picture? Dead. Tasty, but dead.

Alcohol has the same effect: it makes proteins of all kinds, like those found in bacteria and viruses, dead.

Thus, slathering on the hand sanitizer, which is generally on the order of 95% alcohol (go ahead, check the label, I can wait, it will say ethanol or isopropyl) kills your little hitchhiking germy friends, no rinse cycle needed. But as you do not rinse, their little germy corpses remain until the next time you wash your hands.

The Centers for Disease Control, which could otherwise be referred to as “Swine Flu Central” recommends hand washing for what is an interminable amount of time, if you actually do it for the whole time, and let’s face it, no one does. They recommend using an alcohol-based sanitizer only “if soap and water are not available”. So they must know something about the relative effectiveness of each that we do not. Or maybe they just hated “Inglorious Basterds” too. All I know is, some Basterd did not wash or sanitize their hands thoroughly enough, and I lost a whole week to prove it.



  1. You really should post more, Margaret. Your posts are both amusing and informative.

    Along the same line of “The Flu Season”, I’d love to see a post about the flu vaccine and/or H1N1 vaccine (related, I know, how? I don’t know) and maybe all the other “stuff” in a vaccine.

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