triclosan

Triclosan is an organochlorine compound used as a broad-spectrum antimicrobial agent in a variety of consumer products. Its chemical name is 5-chloro-2-(2,4-dichlorophenoxy)phenol, and its molecular formula is C12H7Cl3O2. It has been employed since the 1960s in products intended to reduce or prevent bacterial contamination, including soaps, body washes, toothpaste, cosmetics, and some textiles and plastics.

Triclosan works by inhibiting fatty acid synthesis in bacteria, targeting the enoyl-acyl carrier protein reductase (FabI). This action can be bacteriostatic and is typically more effective in formulations with low amounts of organic matter; its activity decreases in real-world use where soils and organic materials are present. Its broad-spectrum activity has contributed to widespread use, though effectiveness in consumer products has been debated.

Uses and regulation have varied by region. In many markets, triclosan has been phased out of consumer antiseptic hand soaps and washes due to safety and environmental concerns. It remains present in some toothpaste formulations in certain jurisdictions, historically at about 0.3% by weight, and is still allowed in some cosmetics or medical products where permitted by regulation. Regulatory responses emphasize a cautious risk–benefit assessment, with emphasis on safety for daily consumer use and potential alternatives.

Safety and environmental considerations are the subject of ongoing review. Human health effects are not definitively established; some animal studies have suggested endocrine-disrupting effects, while human data are inconclusive. Environmentally, triclosan is persistent in aquatic systems, can affect aquatic organisms, and may form chlorinated byproducts during wastewater treatment. Regulatory and industry actions continue to limit its use and mitigate environmental exposure.