sealPurdue News

March 2000

Hand sanitizers no substitute for soap and water

WEST LAFAYETTE, Ind. – Instant hand sanitizers may not be everything consumers expect, according to a Purdue university professor who teaches sanitation practices for food service workers.

"Waterless, antibacterial hand sanitizers are marketed as a way to 'wash your hands' when soap and water aren't available, and they are especially popular among parents of small children," says Barbara Almanza, associate professor of restaurant, hotel, institutional and tourism management. "But research shows that they do not significantly reduce the overall amount of bacteria on the hands, and in some cases they may even increase it."

Almanza says a hand sanitizer can't take the place of old-fashioned soap and water at home or anywhere else.

"In terms of the regulations regarding food services, the Food and Drug Administration says hand sanitizers may be used as a supplement but not as a substitute for hand washing," Almanza explains. "By the same token, people should not use hand sanitizers in place of a good lathering with soap and water if it's available."

Almanza says the typical hand sanitizer, which is usually alcohol-based, strips the skin of the outer layer of oil, which normally prevents resident bacteria from coming to the surface.

"Generally, this resident flora is not the type that will make us sick," Almanza says, "but the assumption is that when you have an increase in overall bacteria, the chances are better that a disease-causing strain will be present."

Yet the manufacturers of these products can continue to claim that the sanitizers are up to 99.9 percent effective in killing germs because they were tested on inanimate surfaces rather than human hands.

"The physiological complexity of human skin makes it very difficult to use for testing of this nature," Almanza says. "The most clear and consistent results were going to come from using surfaces for which the variables can be controlled, and that's just not real life. Real life is not neat and tidy."

CONTACT: Almanza, (765) 494-9847;

Compiled by Sharon A. Bowker, (765) 494-9723;

Purdue News Service: (765) 494-2096;

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