Many products which are labeled "anti-bacterial" or "anti-microbial" contain triclosan, a chemical that has been shown to have significant health and environmental impacts.

A 2003 University of Minnesota study found that when exposed to UV radiation in sunlight, triclosan breaks down into dioxin, a chemical that has been classified as a probable human carcinogen, and is also known to be an endocrine disruptor. Researchers also suspect that the form of dioxin created by the breakdown of triclosan could become even more toxic with exposure to chlorine, often found in tap water. Triclosan can also break down into chloroform, a probable carcinogen.

In the United States, triclosan's use as a pesticide is regulated by the EPA, but its use in cosmetics, soaps, and other personal care products is monitored by the Food and Drug Administration, which has placed virtually no regulations on its use. Many European nations have either banned or severely restricted the use of triclosan in their consumer products.

Numerous studies show that washing with regular soap and hot water is just as effective at removing germs as is the use of products containing triclosan. For situations where washing isn't possible, a new generation of hand cleaners and bio-based anti-bacterial hand wipes are now on the market.

Resources:

Beyond Pesticides is a national non-profit organization focused on alerting the public to the dangers of pesticides and supporting safe alternatives. They have put together an excellent fact sheet on triclosan.