TAMPA, FL -- Everyone is always looking for ways to keep their families healthy. The CDC says washing your hands is the best way to protect yourself against getting sick.
But is it? What about those hand sanitizers many people carry around. Do they work better? Or at all? We asked some kids from the YMCA and a scientist from USF to help us find an answer.
Afternoons at the Northdale YMCA in Tampa are full of ball games and other activities. Plenty of fingers touched a basketball and this type of exchange is often how viruses and bacteria are spread.
So, what a great place to test whether all hand sanitizers are the same and if soap and water better protect our kids from illness.
We asked 16 nine and ten-year-olds to try eight products, half name brand hand sanitzers and half generics. Four others would try soap and/or just water.
Here's one student's theory: "If you wash your hands with water you get a couple off your hands, but if you use soap and water you'll probably get most of the germs off your hands."
Our test worked like this: Each kid touched their finger tips to a petri dish before treatment. Then a squirt of hand sanitizer and they touched the petri dish again. Most hand sanitizers contain some kind of alcohol compound, either ethyl or isopropyl.
Then we brought the petri dishes to Burt Anderson, a Professor of Molecular Medicine at the University of South Florida. "We put them into an incubator to allow the bacteria to grow."
The results were pretty clear. In the petri dish from one student's test, Burt Anderson says there were 90 to 100 colonies of bacteria before she used Walgreens foaming hand sanitizer.
Afterwards, Anderson made this observation, "In this case it was a hand sanitizer using the compound called benzalkonium choloride. You can see a drastic and dramatic reduction to no colonies at all."
While the Walgreens brand did the best, three other hand sanitizers showed significant reductions in bacteria. Anderson says, "So clearly these hands sanitizers have an effect in reducing the number of bacteria."
Four showed moderate to slight results and only one hand sanitizer showed little to no reduction.
But overall did hand sanitizers beat good old soap and water? Anderson says, "In our particular case, and again our sampling is small, there was not a dramatic difference between the children that washed their hands with soap and water after washing in terms of the total number of bacteria growth. I was a little surprised."
Anderson thinks those results indicate kids aren't washing their hands long enough or correctly.
The
CDC recommends you use warm water and soap for about 20 seconds.
So what should parents and kids take away from this experiment?
Anderson says, "I think it shows the value of hand sanitizers. The CDC recommends it as an alternative to do that also to control the H1N1 virus and it has no negative effect but clearly reduces the number of microbes, bacteria and viruses on your skin."
Test Information
Our hand sanitizer testing method is detailed
here.
The Walgreens Generic Foam Hand Sanitizer was found to eliminate the most bacteria of all the products tested. You can see a list of products tested and the results, click
here, or look at a
graph of the results.
Dr. Burt Anderson BiographyDr. Burt Anderson is a professor with the College of Medicine, Department of Molecular Medicine, at the University of South Florida. He is also an Infectious Disease Researcher at the VA Medical Center, Bay Pines. Earlier in his career he spent ten years working for Centers for Disease Control and Prevention in Atlanta, Georgia.
