hand_sanitizers : Hand Sanitizers vs. Soap and Water

How do hand sanitisers work?

Hand sanitizers work by stripping away the outer layer of oil on the skin. This usually prevents bacteria present in the body from coming to the surface of the hand. However, these bacteria that are normally present in the body are generally not the kinds of bacteria that will make us sick. In a review of the research, Barbara Almanza, an associate professor at Purdue University who teaches safe sanitation practices to workers, came to an interesting conclusion. She notes that the research shows that hand sanitizers do not significantly reduce the number of bacteria on the hand and in some cases may potentially increase the amount of bacteria on the hand. So the question arises, how can the manufacturers make the 99.9 percent claim?

The manufacturers of the products test the products on inanimate surfaces hence they are able to derive the claims of 99.9 percent of bacteria killed. If the products were fully tested on hands, there would no doubt be different results. Since there is inherent complexity in the human hand, testing hands would definitely be more difficult. Using surfaces with controlled variables is an easier way to obtain some type of consistency in the results. But as we are all aware, everyday life is not as consistent.

Current recommendations for hand sanitation

Interestingly enough, the Food and Drug Administration, in regards to regulations concerning proper procedures for food services, recommends that hand sanitizers not be used in place of soap and water but only as an adjunct.

Likewise, Almanza recommends that to properly sanitize the hands, soap and water should be used. A hand sanitizer can not and should not take the place of proper cleansing procedures with soap and water.

Hand sanitizers containing alcohol do not “work” by stripping away the outer layer of oil on the skin. Alcohol containing hand sanitizers destroy the lipid (oil) containing cell membrane of bacteria and fungus and denatures (destroys) proteins and enzymes inside bacteria and fungus. Alcohol kills bacteria and fungus almost instantly upon contact. In addition, alcohol denatures (destroys) the protein or lipoprotein coat of many viruses destroying their ability to infect human cells. A review of several hundred references in the literature on the antimicrobial action of hand sanitizers and antiseptics revealed that hand sanitizers and antiseptics containing alcohol significantly reduce the numbers of microorganism on the skin when properly applied and tested. Only one report was found which did not find a significant reduction in bacteria after using hand sanitizers. That single report, published in 1994, has never been independently confirmed.