Triclosan is the main ingredient in antibacterial soap. The antibacterial properties of biocides are well known that is why manufacturers use it is an ingredient in some pesticides and consumer products like mattresses, insulation, as well as ingestible consumer products like toothpaste and even mouthwash. Unfortunately, Triclosan penetrates the skin on contact and enters the bloodstream.
In 2010 it was discovered that childhood exposure to Triclosan had more hay fever. Ironically, this may be because exposure to bacteria reduces allergies not the toxicity of the Triclosan itself. Other studies have linked Triclosan to allergic contact dermatitis in some individuals.
Triclosan reacts with the chlorine in tap water and produces compounds, like 2,4-dichlorophenol which converts into dioxins upon exposure to UV radiation from the sun or other sources. Only small amounts of dioxins are created, but some of the dioxins are extremely toxic and are very potent disrupters of the endocrine system. Dioxin is also chemically stable, eliminating them from the body takes a long time. Environment Triclosan is very toxic to healthy water-borne bacteria. It also inhibits photosynthesis in essential algae which are crucial the Earth's supply of this life-giving process.
Studies have shown that Triclosan blocks the metabolism of the thyroid hormone in a way so that normal hormones cannot be used. A three-year-long study beginning in 2003 concluded that Triclosan affected the immune system and showed a direct link between low doses of Triclosan with allergy or hay fever.
Testing with mice revealed that Triclosan has impaired excitation-contraction coupling in cardiac and skeletal muscle.
Multiple reports have suggested that Triclosan combines with chlorine in tap water to form chloroform. The EPA classifies chloroform as a human carcinogen.