Triclosan, an antibacterial agent found in many soaps, may increase a person’s exposure to a potentially toxic chemical, new research suggests.
Although there is little evidence of any benefit from using antibacterial soaps instead of regular soaps in the home, people in the United States employ around 1,500 kilograms of triclosan each day in kitchen and personal-care products.
Previous research has shown that triclosan reacts with chlorine, the most common disinfectant for drinking water. The resulting by-products include chloroform, suspected to cause cancer. Chloroform also forms when chlorine reacts with organic material in water.
Environmental chemist Peter J. Vikesland and his coworkers at the Virginia Polytechnic Institute and State University in Blacksburg wondered how much chloroform arises when a person washes dishes or showers with a triclosan-containing product. The researchers tested several antibacterial liquid soaps in purified water and tap-water samples from Atlanta and Danville, Va., by adding a quarter of a gram of soap per liter of water and measuring the reaction products after 1 minute.
The scientists plugged their results into a formula to predict a person’s chloroform exposure. Use of triclosan-containing products could boost the chloroform reaching a person’s skin or airways by 15 to 40 percent over the chemical’s allowable concentration in tap water, the researchers report online and in an upcoming Environmental Science & Technology.
To determine people’s actual exposures to chloroform during dishwashing or showering will require further studies, notes Vikesland. But with the potential for additional chloroform exposure from antibacterial soaps of questionable benefit, “people should think about what they are using and whether they actually need it,” he says.