Hand Sanitizers: Healthy or Hype?

Post date: Feb 12, 2013 7:50:30 AM

Americans spend $175 million on hand sanitizers that claim to kill 99.9 percent of germs, but all too often, we’re not getting the protection we’re paying for. Studies show that sanitizers aren’t very effective against some of the germs we fear most, including colds, flu and the nasty stomach bug norovirus.

However, there’s also research showing that alcohol-based sanitizers can reduce overall rates of GI infections, cut the number of days kids stay home sick from school, and lower illnesses among college students living in dorms.

New studies also raise concern about potential health risks from a widely used hand gel ingredient—and there’s also evidence that many of us use these disinfectants incorrectly. To sift through the confusion, I talked to several infection-control experts.

Here’s a look at some facts and myths about the germ-fighting gel.

Hand gels don’t cut through grime. “Dirt, especially proteins or fatty materials, reduces the effectiveness of hand sanitizer, so alcohol-based hand sanitizers are not suggested if hands are visibly soiled,” says Dr. Daniel Uslan, hospital epidemiologist at UCLA Medical Center, Santa Monica. Instead, wash with soap and water.

It is important to use the product correctly. "Rub the sanitizer over the entire surface of the hands and fingers – including under the nails – just as you would when using soap and water", advises Rekha Murthy, MD, director of hospital epidemiology at Cedars-Sinai Medical Center in Los Angeles.

One type of hand sanitizer actually raises bacteria counts. That was the startling finding of a study comparing various products, according to the CDC. Volunteers placed their dominant hand on plates of agar growth medium (used to grow bacterial cultures in lab dishes) before and after various treatments, such as rinsing with tap water, lathering with antimicrobial soap, or rubbing hands with sanitizers, including one purchased at a discount store.

The next day, culture plates from hands rubbed with the store-bought gel not only had clumps of bacteria, but in some cases, they’d formed a visible outline of the volunteer’s hand. The researchers discovered that the discount product only contained 40 percent alcohol.

Though the study doesn't specifiy which hand sanitizer raised bacteria counts, there have been several voluntary recalls of hand sanitizers due to bacterial contamination, including Kleenex-brand Luxury Foam hand sanitizer in June, 2012 and X3 Clean Alcohol-Free Foaming Hand Sanitizer in November.

Not all disinfectants are equally effective. “It depends on which hand sanitizer [you’re] using,” says Allison Aiello, PhD, associate professor of epidemiology at University of Michigan. “Alcohol-based sanitizer with 60% concentration is very effective at killing a wide range of bacteria and viruses on the hands—and the product of choice in the hospital setting based on rigorous randomized intervention studies.”

However, adds Aiello, for patients, “hand washing with plain soap and water is the preferred regimen, but if a sink is not available, or you are in rush or cannot leave your desk, hand sanitizer is an appropriate alternative.”

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