What is the minimum percentage of alcohol that a hand rub must contain?

The minimum percentage of alcohol that a hand rub must contain is 60%. This concentration is crucial because it is the threshold necessary for the alcohol to effectively kill most pathogens, including bacteria and viruses, on the skin. Alcohol works by denaturing the proteins of these microorganisms, rendering them inactive.

At concentrations lower than this, such as 40% or 50%, the efficacy of the hand rub in killing germs significantly decreases. A 70% concentration is often cited as optimal for disinfection because, while it is efficient at killing germs, it also contains enough water to slow down the evaporation process, allowing the alcohol more time to penetrate cell walls effectively. However, when considering the minimum effectiveness required to ensure sufficient antimicrobial action, 60% stands as the baseline percentage for hand sanitizers.