When are alcohol-based hand rubs considered effective for hand antisepsis?

Alcohol-based hand rubs are considered effective for hand antisepsis specifically when hands are not visibly soiled. This is because alcohol-based hand sanitizers work by destroying a wide range of microorganisms, particularly bacteria and viruses, through their alcohol content. However, their efficacy diminishes significantly in the presence of organic matter, such as dirt, blood, or other visible soils. Hence, for optimal effectiveness, hands should be free from visible contamination.

While it’s important to wash hands with soap and water when they are visibly soiled, the use of alcohol-based hand rubs is not restricted solely to post-washing conditions. They are also effective as a standalone measure when a proper handwashing facility is not available and hands are clean. Although they serve as an alternative to glove use in some contexts, their effectiveness is contingent on the cleanliness of the hands, rather than the availability of gloves or the requirement for a surgical mask.