The cover story for this week’s C&E News (June 23, 2014) is called Triclosan Under the Microscope. Triclosan is mainly used as an anti-bacterial additive. According to the article, small amounts of triclosan are routinely added to “soaps, bodywashes, deodorants, toothpaste, shaving gel, and cosmetics, as well as products such as dishwashing liquids, laundry detergents, cutting boards, toys, fabrics, shoes, and caulking compounds,” which are subsequently marketed as “antibacterial.”
All of this might be fine if triclosan could be persuaded to stay put inside these products, but to be effective as anti-bacterial, it needs to be released into the places where germs might appear: our skin, teeth, dish water, clothes, and so on. This fact, along with concerns over possible adverse health consequences associated with prolonged triclosan exposure, and also triclosan’s ability to migrate far and wide through the natural environment, encouraged Minnesota legislators to ban triclosan-containing soaps and cleaning products last month.
As the article makes clear, the triclosan story is not an easy one to resolve. More scientific and health studies are needed. One study mentioned in the article was a 2010 investigation led by (then U. Minnesota, now ETH-Zurich) Prof. Kris McNeill ’92 (“Dioxin Photoproducts of Triclosan and Its Chlorinated Derivatives in Sediment Cores,” DOI: 10.1021/es1001105). This study showed that triclosan undergoes photochemical reactions once it reaches the environment that convert triclosan molecules into potentially harmful versions of another chemical of concern, dioxin.