Triclosan

What It Is

Triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether) is a synthetic antimicrobial and antifungal agent (CAS 3380-34-5). It is a white to off-white crystalline powder that is poorly soluble in water but soluble in organic solvents. Triclosan was one of the most widely used antimicrobial agents in consumer products for over 40 years before regulatory actions significantly curtailed its use. It functions as a bacteriostatic agent at low concentrations and a bactericidal agent at higher concentrations.

Common Uses

Triclosan was historically used in antibacterial hand soaps, body washes, toothpastes, deodorants, household cleaning products, cutting boards, and textiles. At its peak, triclosan appeared in an estimated 75% of antibacterial liquid hand soaps sold in the United States. Following the FDA's 2016 ban on triclosan in over-the-counter consumer antiseptic wash products, its use in personal care has declined dramatically. Triclosan remains permitted in some product categories, including toothpaste (where it is the active ingredient in Colgate Total) and certain industrial applications.

How It Works

At low concentrations, triclosan acts as a bacteriostatic agent by inhibiting the enzyme enoyl-acyl carrier protein reductase (FabI), which is essential for bacterial fatty acid synthesis. This blocks the production of cell membrane components, preventing bacterial growth. At higher concentrations, triclosan disrupts cell membranes directly, producing bactericidal effects. Triclosan is most effective against gram-positive bacteria and has limited activity against Pseudomonas species and most fungi.

Because triclosan targets a specific enzyme, there has been concern about bacterial resistance development. Laboratory studies have demonstrated that bacteria can develop reduced susceptibility to triclosan through mutations in the FabI gene or through efflux pump upregulation (Levy, 2001).

Safety and Regulation

In September 2016, the FDA issued a final rule banning triclosan and 18 other antimicrobial active ingredients from over-the-counter consumer antiseptic wash products (soap and water formulations), finding that manufacturers had not demonstrated that these ingredients are both safe for long-term daily use and more effective than plain soap and water (FDA, 81 FR 61106, 2016).

Triclosan is an endocrine disruptor in laboratory animal studies, affecting thyroid hormone homeostasis at exposure levels above typical human use. It is also persistent in the environment and has been detected in surface water, sediment, and human biomonitoring studies (Calafat et al., 2008). The EPA has registered triclosan as a pesticide for certain industrial uses and reviews it under FIFRA.

Triclosan is not classified as a carcinogen, though a 2014 study reported liver tumor promotion in mice exposed to triclosan (Yueh et al., 2014). The EU has restricted triclosan in cosmetics to a maximum of 0.3% and only in specific product categories (toothpastes, hand soaps, body soaps).

Why Natural Flower Power Does Not Use It

Natural Flower Power does not use triclosan in any product.

The FDA's 2016 ban on triclosan in consumer antiseptic wash products effectively summarizes the issue: after decades of use, manufacturers could not demonstrate that antibacterial soaps containing triclosan were more effective than washing with regular soap and water. Our hand soaps work the way all soaps work -- surfactants dislodge bacteria and viruses from skin so they can be rinsed away. We do not need an antimicrobial active ingredient to accomplish that. Adding triclosan would introduce endocrine disruption concerns and environmental persistence without a demonstrated performance benefit for the type of products we make.

Related Ingredients

Triclocarban is another synthetic antimicrobial banned alongside triclosan in the FDA's 2016 rule. Benzalkonium chloride is a quaternary ammonium antimicrobial that remains permitted in some antiseptic products. Tea tree oil and thyme oil are essential oils with natural antimicrobial properties that NFP uses in some formulations for supplementary antimicrobial activity. Benzisothiazolinone (BIT) is a preservative (not an antimicrobial wash active) that serves a different function from triclosan.

Sources

• U.S. Food and Drug Administration. "Safety and Effectiveness of Consumer Antiseptics; Topical Antimicrobial Drug Products for Over-the-Counter Human Use." 81 FR 61106, September 6, 2016.
• Levy, S.B. "Antibacterial Household Products: Cause for Concern." Emerging Infectious Diseases, vol. 7, no. 3 Suppl, 2001, pp. 512-515.
• Calafat, A.M., et al. "Urinary Concentrations of Triclosan in the U.S. Population." Environmental Health Perspectives, vol. 116, no. 3, 2008, pp. 303-307.
• Yueh, M.F., et al. "The Commonly Used Antimicrobial Additive Triclosan Is a Liver Tumor Promoter." PNAS, vol. 111, no. 48, 2014, pp. 17200-17205.