Triclosan is a commonly used antimicrobial agent that accumulates in our bodies and has been linked to hormone disruption and the emergence of bacteria resistant to antibodies and antibacterial products. The Centers for Disease Control and Prevention have identified triclosan in the urine of 75 percent people tested . Triclosan also impacts the environment, ending up in lakes, rivers and other water sources, where it is toxic to aquatic life.
What you need to know
Found in: Antibacterial soaps and detergents, toothpaste and tooth whitening products, antiperspirants/deodorants, shaving products, creams
What to look for on the label: Triclosan
Health concerns: Endocrine disruption, allergies and immunotoxicity, bioaccumulation, organ system toxicity, irritation
Vulnerable populations: Pregnant women and breast-feeding mothers
Regulations: Restricted in cosmetics in Canada and Japan
What is triclosan?
Triclosan is an antimicrobial agent found in a wide variety of antibacterial soaps and detergents, as well as in many deodorants, toothpastes, cosmetics, fabrics and plastics. Triclosan was initially developed as a surgical scrub for medical professionals, but in recent years it has been added to a host of consumer products, from kitchen cutting boards to shoes, in order to kill bacteria and fungus and prevent odors. However, triclosan has proved to be both dangerous and unnecessary—in 2005, the FDA found no evidence that antibacterial washes containing triclosan were superior to plain soap and water for protecting consumers from bacteria , and in 2013 the FDA announced a draft rulemaking process that would require manufacturers to demonstrate triclosan’s safety and efficacy for use in soaps and body washes  . This process will not be finalized until 2015 and does not include hospital-based use of triclosan.
What are the health concerns?
Endocrine disruption: There is evidence that triclosan is an endocrine disruptor and impacts thyroid function and thyroid homeostasis. A 2009 study found that triclosan decreased thyroid hormone concentrations , and another showed that triclosan enhanced the expression of androgen and estrogen sensitive genes .
Triclosan-resistant bacteria: Since 2000, a number of studies have found microorganisms that are resistant to triclosan, and there is mounting evidence linking the use of triclosan with the promotion of bacteria that are resistant to both antibiotic medications and antibacterial products [6,7]. For instance, triclosan-resistant strains of microorganisms such as E. coli and salmonella have been identified [8,9,10]. Studies indicate that use of triclosan provides a suitable environment for the emergence of antimicrobial drug-resistant bacteria, even at the low concentrations found in many FDA-regulated products and cosmetics. Because triclosan’s mode of action and target site in bacteria are similar to those of antibiotics, there are concerns that bacteria that become resistant to triclosan will also become resistant to antibiotics. A 2010 report by the European Commission’s Scientific Committee on Consumer Safety determined that even low concentrations of triclosan can trigger antibiotic resistance in bacteria .
Bioaccumulation: Triclosan is lipophilic, meaning that it accumulates in fatty tissues. Studies have found concentrations of triclosan in three out of five human milk samples [12,13]. Triclosan has also been found in the umbilical cord blood of infants . These results raise concerns for the fetus during vulnerable periods of development, and make the bioaccumulative and endocrine-disruptive potential of triclosan even more alarming. Since the majority of the products that contain triclosan are eventually washed down consumers’ residential drains, high levels of triclosan are accumulating in water systems and negatively impacting the environment. Triclosan is toxic to algae (because algae is a first-step producer, the destruction of algae is particularly disruptive to aquatic ecosystems) and there is evidence that triclosan is accumulating at high levels in fish and other aquatic life .
How can you avoid this?
Triclosan should be clearly labeled on ingredient lists and so is relatively easy to avoid. Stick with plain soap and water—the FDA found no evidence that antibacterial washes containing triclosan are any more effective at protecting against bacteria .
Further information including links to reports, press releases and to take the Triclosan-Free Pledge
 Calafat, A., et al. 2008. Urinary Concentrations of Triclosan in the U.S. Population: 2003–2004. Environ Health Perspect 116:303–307.
 Alastair Wood, M.D. (Committee Chair), FDA Non-Prescription Drugs Advisory Committee. October 20, 2005 meeting transcript p. 354-355. Available online: http://www.fda.gov/ohrms/dockets/ac/cder05.html#NonprescriptionDrugs. Accessed November 5, 2013.
 FDA (2013). FDA taking a closer look at antibacterial soap. Available online: http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm378393.htm. Accessed December 20, 2013.
 Zorrilla, L., et al (2009). The effects of Triclosan on Puberty and Thyroid Hormones in Male Wistar Rats. Toxicological Sciences. 107(1) 56-64.
 Ahn et al (2008). In Vitro Biologic Activities of the Antimicrobials Triclocarban, Its Analogs, and Triclosan in Bioassay Screens: Receptor-Based Bioassay Screens. Environ Health Perspectives. 116(9): 1203–1210.
 Heath, R., et al (2000). Inhibition of the Staphylococcus aureus NADPH-dependent enoyl-acyl carrier protein reductase by triclosan and hexchlorophene. Journal of Biological Chemistry. 275: 654-59.
 Aiello, A.E., et al (2005). Antibacterial Cleaning Products and Drug Resistance. Emerging Infectious Diseases. 11(10).
 Levy, S.B. (2000). Antibiotic and antiseptic resistance: Impact on public health. Pediatric Infectious Disease. 19(10): S120–2.
 Yazdankhah, S.P., et al (2006). Triclosan and antimicrobial resistance in bacteria: An overview. Microbial Drug Resistance-Mechanisms Epidemiology and Disease. 12(2): 83-90.
 Davies, A.J., Maillard, J.Y. (2001). Bacterial adaptation to biocides: the possible role of `alarmones'. Journal of Hospital Infection. 49(4).
 SCCS (Scientific Committee on Consumer Safety), Preliminary opinion on triclosan antimicrobial resistance), 23 March, 2010. European Commission, Brussels.
 Adolfsson-Erici, M., M. Pettersson, J. Parkkonen, and J. Sturve (2002). Triclosan, a commonly used bactericide found in human milk and in the aquatic environment in Sweden. Chemosphere. 46: 1485-1489.
 Allmyr, M., et al. (2006). Triclosan in plasma and milk from Swedish nursing mothers and their exposure via personal care products. Science of The Total Environment. 372(1): 87-93.
 Greenpeace and WWF. 2005. A Present for Life: Hazardous chemicals in umbilical cord blood. Available from: http://eu.greenpeace.org/downloads/chem/Umbilicalcordreport.pdf.
 Adolfsson-Erici, M., et al. 2002. Triclosan, a commonly used bactericide found in human milk and in the aquatic environment in Sweden. Chemosphere 46:1485-1489.