Three quarters of national brand liquid soaps and about one-third of bar soaps contain triclosan and triclocarban, respectively, according to a study done in 2001. These chemicals are chlorinated hydrocarbons that can kill many bacteria and some fungi and can also be found in other products, such as toothpaste, mouthwash, and even toys.
Triclosan prevents bacteria by interfering with a protein that they need to generate new lipids and build their cell walls. The bacteria can begin to grow, but if they don't have a cell wall, they will break the cells, killing them. By contrast, regular soap mechanically removes bacteria but doesn't necessarily kill them. It dislodges bacteria from the skin, and washes that bacteria down the drain.
So the most important question is, are antibacterial soaps really better at preventing illness? The FDA has serious doubts, which is why they have tasked soap manufacturers with proving the effectiveness of their antibacterial soaps. Manufacturers must show that antibacterial soaps are are superior at reducing the risk of illness then regular soap, that it warrants the use of triclosan and triclocarban. Thus, the FDA has given soap manufacturers one year to provide clinical trial data that show that the health benefits (namely, preventing illness) outweigh the risk of using these hydrocarbons.
Possible Health Risks Associated with Triclosan and Triclocarban
These chemicals can possibly make bacteria resistant to other antibiotics that are important for controlling infections.
Studies have suggested that triclosan and triclocarban can cause alterations in thyroid, reproductive growth, and developmental systems of neonatal and adolescent animals. While these studies do not involve humans, researchers interpret the animal studies as flagging the chemicals as a potential risk.