I’m a big fan of those alcohol-based gel hand sanitizers. I’m already a bit of a hypochondriac so I didn’t feel as weird this year when everyone started to use them during the H1N1 pandemic. After all, everyone knows they kill 99.9% of germs. Right? Well, um, sort of. The Wall Street Journal has a cool “Numbers Guy” column, and recently he discussed exactly what those sanitizer companies need to do to make those claims. Apparently, at least in the U.S., they must follow very strict guidelines to prove this — but not technically against viruses such as H1N1. In fact, saying 99.9% still doesn’t mean that it is effective against all germs, just against many. Plus, these tests are done in labs and not in real-world conditions. One doctor performed just such a test with perfect subjects — schoolkids. He only got 46-60% effectiveness. Of course, one big reason may be improper use of the gels (not enough time, not enough amount). It’s the same problem with birth control: the published rates of efficacy at 99% are far higher than real world effectiveness in the low 90′s. …Continue reading: Kills 99.9% of Germs — Sometimes…