If hand sanitizer kills 99.9% of germs, what stops us from using that all of the time instead of hand washing?

Question

If hand sanitizer kills 99.9% of germs, what stops us from using that all of the time instead of hand washing?

In: Biology

Answer 1

Nothing, really. The problem is that killing 99.9% of germs is usually not enough. Microbial colonies such as what you’d find on our skin can be made up of millions of individual bacteria. Wiping out 99.9% of a few million cells still leaves enough microbes to multiply and reach the same numbers after a surprisingly short time – many bacteria divide into two cells in a matter of minutes, and follow an exponential growth pattern.