For killing germs on your hands, alcohol has long been the go-to ingredient in many hand sanitizers. Now, some companies are selling alcohol-free sanitizers with antimicrobials they say give long-lasting protection without drying hands.
Editor note: Various companies have been promoting alcohol-free hand sanitizers for the past 10+ years. In 2009, Gojo Industries sued the owners of the leading alc-free brand ("Hy5") for "irreparably damaging Gojo and its product Purell by making claims that suggested alcohol hand sanitizers irritate the skin.
Some scientists say there is insufficient real-world evidence to show the new sanitizers work as well as they do in lab tests.
Many hand sanitizers, which gained popularity in the 1990s, contain alcohol, which provides a quick kill but evaporates in a few seconds—meaning users can pick up more bacteria as soon as they touch something, scientists say. And frequent users of alcohol-based sanitizers, such as nurses, sometimes complain of dry hands, doctors say.
The website of SafeHands LLC, Boca Raton, Fla., markets its alcohol-free sanitizer, made with the antimicrobial benzalkonium chloride, as "tough on germs and safe on skin." Another sanitizer, 4 Hour Protection sold by Angel Dough Ventures LLC, Hicksville, N.Y., has the same active ingredient and offers "moisturizing, long-lasting coverage," according to the company's website.
Zylast from Innovative BioDefense Inc. in Lake Forest, Calif., is made with an antimicrobial called benzethonium chloride. According to its website, Zylast is "persistent for six hours," which the company says means it maintains a reduction in bacteria six hours after application.
The nonalcohol antimicrobials—which are in a chemical family called quaternary ammonium compounds, or "quats"—do kill germs, scientists say. But they say alcohol-based sanitizers have more published research showing real-world benefits, such as lower incidence of illness among college students or reduced infections in hospitals.
For this reason, the Centers for Disease Control and Prevention recommends alcohol-based products—in addition to handwashing—for health-care workers, says Katherine Ellingson, an epidemiologist at the CDC. For the nonalcohol antimicrobials, "we need studies to look at clinical outcomes," such as reduced transmission of infection in health-care settings, she adds.
Editor note: This is exactly what CDC has been saying for the past 7 years. They also say it is not their role to perform studies. Consultants to CDC include select individuals who are full-time advisers to GOJO Industries.
To show Zylast works for hours, Innovative BioDefense funded a study done at Pace University in New York that tested the product by applying it to swatches of pig skin. After a specified amount of time, the swatches were then put into contact with a bacterial sample. According to a copy of the unpublished report, Zylast lotion killed 98% of E. coli bacteria at two minutes after application, 88% four hours after application and 89% at eight hours. Innovative BioDefense says a study is under way testing Zylast's effect on elementary-school absenteeism, and additional research is planned on illnesses on cruise ships and in nursing homes.
The formula in 4 Hour Protection hasn't been studied to see how it performs after drying on skin for several hours, says Don Muir, executive vice president of MicroArmor Inc. of Willoughby, Ohio, which makes the product for Angel Dough. But he says published data in the August 1998 journal of the Association of periOperative Registered Nurses on a sanitizer with the same active ingredient shows sustained activity. The study used a formulation that was a precursor to the one used in the SafeHands product, according to David L. Dyer, who is a co-author of the study and co-inventor of SafeHands.
It is true quats linger on the hands while alcohol evaporates in 10 or 20 seconds, says Jason Tetro, a microbiologist at the University of Ottawa in Ontario. Mr. Tetro works in a university lab that does tests for hand sanitizers, including Purell. But in real-life use, quats in their dry state may not effectively kill bacteria as moisture is needed for their action, he adds, or they could rub off or get covered by dust. "You will have a much less dramatic persistence in the field," he says. "It's no fault of the product. It has to do with the way we live."
Jesse Cozean, vice president of research and development at Innovative BioDefense, says it is true the company's test doesn't translate directly to real-life benefits but it does show the product is more likely to provide lasting protection than alcohol-based sanitizers.
MicroArmor's Mr. Muir adds not all of the 4 Hour Protection product will rub off and moisture on the hands is enough to allow it to work. The company's website says the product provides "continuous effectiveness" when applied every two to four hours along with handwashing.
Dr. Dyer, who is a molecular biologist and a paid consultant to SafeHands for research and development, says he agrees with the CDC that "there is a paucity of clinical studies associated with alcohol-free sanitizers." SafeHands is planning three clinical trials on its product that will look both at the skin condition of nurses and other users, and at how use of the product affects transmission of infections in hospitals, he adds.
As proof that its nonalcohol sanitizer doesn't dry or irritate the skin, SafeHands points to a company-funded study performed at California State University, Fresno. In the test of 20 volunteers who used the product 10 times over several hours, no redness or other visual signs of irritation were seen; one subject complained of mild itchiness.
According to Dave Macinga, a microbiologist for Gojo Industries Inc., the maker of Purell, a popular hand sanitizer that has ethyl alcohol as its active ingredient, it is an "absolute misconception" that alcohol-based sanitizers dry your hands. He also says moisturizers are added.
In a Gojo-funded study published in 2000 (13 years ago) n the journal Infection Control and Hospital Epidemiology, 32 nurses used Purell for two weeks for an average of about twice an hour during their workdays. It found Purell caused no hand irritation or dryness and proved gentler on the hands than soap and water. The study used an older formula replaced last year with Purell Advanced, an alcohol-based product the company says is more effective at killing bacteria and even easier on the skin.
