Triclosan is an active antimicrobial agent. Triclosan is regulated by both the FDA, where it is registered as a drug, and the EPA, where it is registered it as a pesticide. It is likely that you have frequent contact with triclosan.
Triclosan may be found in items used by consumers, such as hand soaps, body washes, toothpastes, mouthwashes, acne medications, deodorants, and wound disinfection solutions. It also has commercial and industrial uses and may be incorporated into ice-making equipment and applied directly to commercial HVAC coils to prevent microbial growth. It may also be found in fabrics, vinyl, plastics (including toys, toothbrushes, and kitchen utensils), textiles (footwear, clothing), carpeting, and a wide variety of other products.
Results of recent studies are alarming, to the point that both the FDA and the EPA are currently reviewing the use of triclosan. From the EPA
Given the rapidly developing scientific database for triclosan, the Agency intends to accelerate the schedule for the registration review process for this chemical. Currently, the Agency intends to begin that process in 2013, ten years earlier than originally planned.From the FDA
In light of questions raised by recent animal studies of triclosan, FDA is reviewing all of the available evidence on this ingredient’s safety in consumer products. FDA will communicate the findings of its review to the public in winter 2012.What we do know so far is that studies on animals have shown that triclosan disrupts thyroid and testosterone hormones and impairs contraction of heart muscle cells and skeletal muscle fiber cells. There is real concern that the use of triclosan may contribute to making bacteria resistant to antibiotics. Many uses of triclosan result in it being washed down the drain. Even when wastewater is treated it still contains triclosan and when the wastewater is released to the environment, sunlight converts some of the triclosan (and related compounds) into dioxins.
[O]ver the last 30 years, the levels of the four dioxins derived from triclosan have risen by 200 to 300 percent, while levels of all the other dioxins have dropped by 73 to 90 percent.As pointed out by the FDA, there is no evidence that those antibacterial soaps and body washes which contain triclosan provide any extra health benefits over plain soap and water. Until the FDA and EPA make their determinations, if you want to use an "antibacterial" soap choose one that doesn't contain triclosan. Personally, I am going to avoid triclosan every chance I get.