November 18th, 2009 by Potato

One of the first great breakthroughs of evidence-based medicine was Semmelweis (and again Lister) discovering the vast improvement in patient outcomes when doctors wash their hands. “Hand hygene” is one of the cheapest, best ways to prevent disease transmission, whether from doctor to patient, or from the environment to your mouth during flu season. Yet it’s very difficult to get people to actually do it every time.

How often do you see people leave the public washroom without washing their hands? Yes, Penn & Teller demonstrated that your hands were probably dirtier before touching your junk that’s been safely & cleanly ensconced in your undies, but nonetheless, it’s important to wash your hands regularly, and that’s the socially accepted time to do it.

I understand that it is difficult for healthcare workers — after washing my hands 20 times per day I’m definitely reaching for the hand cream when I get home, so up to a hundred times a day has got to be killer. But hey, hazards of the workplace and all. Deal.

Outside of the hospital, soap and water aren’t always readily available or convenient, so alcohol-based hand sanitizers have been installed, which I think can only be good, especially in schools and malls. When these things first came out (around SARS), I had serious doubts as to how effective they could possibly be — after all, even if they killed germs, they’d still leave everything on your hands. Of course, at the time, I was working in a wet lab and was more concerned with chemical contamination than bacterial. For preventing the spread of disease though, they look to work just fine (but I am too lazy to review the literature at this time).

Freakonomics had a blog entry about handwashing compliance and in the comments, one person was concerned about the possibility that all this hand sanitizer use would lead to bacteria developing resistance to it. As one reply so elegantly put it, that would be like humans developing resistance to being doused in gasoline and set on fire. That’s not to say that some bacteria won’t escape, especially if you miss a spot, or don’t use enough to get into the fissures of your skin… that’s just not likely to be an inheritable trait.

Speaking of fire: Yes, alcohol is flammable. Incredulously, I heard that some schools were banning, or considering banning, hand sanitizer for this reason (and also for the “martini dispenser” issue). I wondered though if gelled alcohol was flammable. Sticking my head in the kitchen and uttering those words that always make Wayfare cringe in fear — “Wanna do Science?” — I set out to test it experimentally. With a lighter, I could set some hand sanitizer on fire. That’s still not a particularly good reason to keep it out of schools (I’m not a fire expert, but it didn’t really seem all that much more flammable than paper, and paper doesn’t evaporate in seconds). Vigorously rubbing my hands together (the intended method), did not start a friction fire.

Setting Hand Sanitizer on Fire in a Pot. Direct contact with open flame was used as an ignition source.

One Response to “Handwashing”

  1. Rez Says:

    There are lots of youtube vids of kids gelling up their hands, lighting it on fire, and playing fun games. I’ve tried it. It’s cool–I mean hot.