The down side to clean hands

Handwashing with antibacterial soap exposes hospital workers to significant and potentially unsafe levels of triclosan, a widely-used chemical currently under review by the US Food and Drug Administration (FDA), according to a study led by researchers from University of California San Francisco (UCSF).

Triclosan is a synthetic antibacterial agent found in many consumer products, including soaps, cosmetics, acne creams and some brands of toothpaste.

In the current study, published in the August issue of the Journal of Occupational and Environmental Medicine, researchers analysed urine samples from two groups of 38 doctors and nurses - three-fourths of them women - at two hospitals, identified as Hospital 1 and Hospital 2. Hospital 1 used an antibacterial soap containing 0.3% triclosan, while Hospital 2 used plain soap and water.

Workers at Hospital 1 had significantly higher levels of triclosan in their urine than workers at Hospital 2.

The scientists also asked the study participants if they used a popular commercial toothpaste containing triclosan. While those who did had higher triclosan levels than those who did not, the researchers found that washing with antibacterial soap accounted for even higher triclosan levels than did brushing with the toothpaste.

“Antimicrobial soaps can carry unknown risks, and triclosan is of particular concern,” said co-investigator Paul Blanc, MD, a professor of medicine at UCSF who holds the Endowed Chair in Occupational and Environmental Medicine. “Our study shows that people absorb this chemical at work and at home, depending on the products that they use.”

Blanc recommended: “If non-triclosan-containing soaps are available, use the alternative”.

For people who want to replace antibacterial products in their home with something safer, Blanc says, “Just plain soap and water is a pretty good alternative.”