What is Triclosan and Why is it Being Banned?

Triclosan has been in the media recently, in it's battle with regulation in its existence in many cleansing products.  In a recent article by the C&EN News they reported that "Minnesota state agencies will be able to purchase only soaps and detergents that are free of the antibacterial ingredient triclosan. State officials say they are concerned that the chemical has been linked to endocrine disruption and the growing threat of antibiotic resistance."

What is Triclosan, and how long have we been in contact with this reportedly "harmful" chemical? 
It has been used commonly in many different products since 1972 when it first became apparent that it reduced bacterial activity.  Such products as toothpaste, mouthwash, deodorant, trash bags, kitchen tools, and many other areas where antibacterial products seemed appropriate for manufacturers to use for preserving their products, or making their cleaning products more affective.

Why is it being banned?
It is being banned for a number of reasons.  First of all, as mentioned by C&EN, the risk of upsetting endocrine function.  This hasn't necessarily been proven in human subjects (other than slightly affecting the immune system, which may be due to the vast number of bacteria in, and around the body ¹), but it has been reported that the North American Bullfrog's endocrine system becomes compromised under low doses of Triclosan ².  Another reason is that it has been proven that it decreases bacterial species diversity, in other words, selects for antibiotic resistance.  The third reason is that it can be harmful to the environment for the reasons stated above (i.e. disrupting aquatic bacteria), along with Triclosan's byproducts such as dioxins being harmful.

How to avoid using products with Triclosan?
If you don't wish stay free of this product, read labels, and educate yourself of what is in the products you are using. It may also be listed under trade names of UltraFresh, Amicor, or BioFresh.

References:
Via: C&EN
1. Erin M. Rees Clayton, Megan Todd, Jennifer Beam Dowd, Allison E. Aiello. "The Impact of Bisphenol A and Triclosan on Immune Parameters in the U.S. Population, NHANES 2003–2006". Environ Health Perspect 119 (3): 390–396. doi:10.1289/ehp.1002883

2. Nik Veldhoen, Rachel C. Skirrow, Heather Osachoff, Heidi Wigmore, David J. Clapson, Mark P. Gunderson, Graham Van Aggelen and Caren C. Helbing. "The bactericidal agent triclosan modulates thyroid hormone-associated gene expression and disrupts postembryonic anuran development". Aquatic Toxicology 80 (3): 217–227. doi:10.1016/j.aquatox.2006.08.010