Triclosan

Triclosan and triclocarban are commonly used antimicrobial agents found in many soaps and detergents.[1] The Center for Disease Control and Prevention has identified triclosan in the urine of 75 percent people tested.[2] Widespread use with few regulations has led to concerns regarding their effects on humans and the environment, such as endocrine disruption, bioaccumulation, and the emergence of bacteria resistant to antibodies and antibacterial products.

FOUND IN: Antibacterial soaps and detergents, toothpaste and tooth whitening products, antiperspirants/deodorants, shaving products, creams, color cosmetics.

WHAT TO LOOK FOR ON THE LABEL: Triclosan (TSC) and triclocarban (TCC)

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. It 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. MORE...

 Triclocarban was first introduced in the market in 1957 as an antimicrobial agent. Over the past few decades, consumption of triclocarban has increased in the US and worldwide. Today, triclocarban is mostly found in bar soaps, but can be found in other types of soaps, clothing, carpets, plastics, toys, and more.

Triclosan and triclocarban have proved to be both dangerous and unnecessary. In 2005 the FDA found no evidence that antibacterial washes containing either triclosan or triclocarban were superior to plain soap and water for protecting consumers from bacteria,[3] and in 2013 the FDA announced a draft rulemaking process that would require manufacturers to demonstrate their safety and efficacy for use in soaps and body washes.[4] This process will not be finalized until 2016 and does not include hospital-based use. As more evidence mounts for triclosan and triclocarban’s toxicity, efforts have begun to diminish their inclusion in consumer products.[5] 

HEALTH CONCERNS: Endocrine disruption, triclosan-resistant bacteria, environmental toxicity (bioaccumulation).  MORE...

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,[6] and another showed that triclosan enhanced the expression of androgen and estrogen sensitive genes.[7]

Several studies report triclocarban as a unique type of endocrine disrupting compound that amplifies endocrine activity when paired with naturally occurring hormones in the human body.

Research has shown that triclocarban enhances the strength of estradiol and testosterone, even though it does not have a direct effect on endocrine activity on its own.[8],[9],[10] Hormone sensitive breast cancer cells lines treated with triclocarban demonstrated increased cell proliferation (growth and multiplication) and increased hormone response.[11],[12] Studies performed on mammalian cells suggest that triclocarban may disrupt thyroid activity[13] and that it also exhibits weak estrogenic activity in fish.[14]

Triclosan-resistant bacteria: Since 2000, a number of studies uncovered triclosan-resistant micro-organisms, 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.[15],[16] For instance, triclosan-resistant strains of microorganisms such as E. coli and salmonella have been identified.[17],[18],[19] 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 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.[20]

Bioaccumulation/Environmental Toxicity: Triclosan is lipophilic, meaning that it accumulates in fatty tissues. Studies have found concentrations of triclosan in three out of five human milk samples.[21],[22] Triclosan has also been found in the umbilical cord blood of infants.[23] 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.

Although touted as effective microbe-killing agents, triclosan and triclocarban are actually many times more likely to kill algae, crustaceans, and fish.[24] Because of their proliferative use, large quantities of these two chemicals often end up in sewage systems, persisting in forestry and non-agricultural settings which can lead to decade long exposure of plants, soil-dwelling biota, and their predators over multiple generations.[25] Biosolids (nutrient-rich organic materials extracted from sewage sludge) are important for crop plant cultivation. Biosolids derived from triclocarban and triclosan have adverse effects on these crops; a study observed a significant decrease in shoot mass for lettuce plants exposed to triclocarban.[26] Furthermore, there is evidence that triclosan is accumulating at high levels in fish and other aquatic life.[27] 

VULNERABLE POPULATIONS: All populations, especially pregnant women and breast-feeding mothers.

REGULATIONS: Triclosan is restricted in cosmetics in Canada and Japan; triclocarban is restricted in cosmetics use in the European Union and is classified to be toxic or harmful by the Environment Canada Domestic Substance List.[28] The EPA regulates triclosan as a pesticide and is currently updating its assessment of the effects of triclosan as a pesticide.[29]

HOW TO AVOID: Avoid products that indicate triclosan and triclocarban on the label. Stick with plain soap and water—the FDA found no evidence that antibacterial washes containing triclosan are any more effective at protecting against bacteria.[30]

References

[1] Halden RU. “On the need and speed of regulating triclosan and triclocarban in the United States.” Environ Sci Technol. 2014 Apr 1;48(7):3603-11. Print.

[2] Calafat A et al. “Urinary Concentrations of Triclosan in the U.S. Population: 2003-2004.” Environ Health Perspect. 116:303-307. Print.

[3] Wood A. 2005. FDA Non-Prescription Drugs Advisory Committee. Available online: http://www.fda.gov/ohrms/dockets/ac/cder05.html#NonprescriptionDrugs. Accessed November 5, 2013.

[4] FDA’s Consumer Updates. FDA Taking Closer Look at “Antibacterial” Soap. Available online: http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm378393.htm. Accessed June 23, 2015

[5] Halden RU. “On the need and speed of regulating triclosan and triclocarban in the United States.” Environ Sci Technol. 2014 Apr 1;48(7):3603-11. Print.

[6] Zorrilla L, Gibson EK, Jeffay SC, Crofton KM, Setzer Wr, Cooper RL, and Stoker TE. “The effects of Triclosan on Puberty and Thyroid Hormones in Male Wistar Rats.” 107(1) 56-64. Print.

[7] Ahn KC, Zhao B, Chen J, Cherednichenko G, Sanmarti E, Denison MS, Lasley B, Pessah IN, Kültz D, Chang DP, Gee SJ, Hammock BD. “In vitro biologic activities of the antimicrobials triclocarban, its analogs, and triclosan in bioassay screens: receptor-based bioassay screens.” Environ Health Perspect. 2008 Sep;116(9):1203-10. Print.

[8] Ahn KC, Zhao B, Chen J, Cherednichenko G, Sanmarti E, Denison MS, Lasley B, Pessah IN, Kültz D, Chang DP, Gee SJ, Hammock BD. “In vitro biologic activities of the antimicrobials triclocarban, its analogs, and triclosan in bioassay screens: receptor-based bioassay screens.” Environ Health Perspect. 2008 Sep;116(9):1203-10. Print.

[9] Chen J, Ahn KC, Gee NA, Ahmed MI, Duleba AJ, Zhao L, Gee SJ, Hammock BD, and Lasley BL. “Triclocarban enhances testosterone action: a new type of endocrine disruptor?” Endocrinology. 2008 Mar;149(3):1173-9. Print.

[10] Huang H, Du G, Zhang W, Hu J, Wu D, Song L, Xia Y, and Wang X. “The in vitro estrogenic activities of triclosan and triclocarban.” J Appl Toxicol. 2014 Sep;34(9):1060-7. Print.

[11] Christen V, Crettaz P, Oberli-Schrämmli A, and Fent K. “Some flame retardents and the antimicrobials triclosan and triclocarban enhance the androgenic activity in vitro.” Chemosphere. 2010 Nov;81(10):1245-52. Print.

[12] Huang H, Du G, Zhang W, Hu J, Wu D, Song L, Xia Y, and Wang X. “The in vitro estrogenic activities of triclosan and triclocarban.” J Appl Toxicol. 2014 Sep;34(9):1060-7. Print.

[13] Hinther A, Bromba CM, Wulff JE, and Helbing CC. “Effects of triclocarban, triclosan, and methyl triclosan on thyroid hormone action and stress in frog and mammalian culture systems.” Environ Sci Technol. 2011 Jun 15;45(12):5395-402. Print.

[14] Zenobio JE, Sanchez BC, Archuleta LC, and Sepulveda MS. “Effects of triclocarban, N,N-diethyl-meta-toluamide, and a mixture of pharmaceuticals and personal care products on fathead minnows (Pimephales promelas).” Environ Toxicol Chem. 2014 Apr;33(4):910-9. Print.

[15] Heath R, Li J, Roland GE, and Rock CO. “Inhibition of Staphylococcus aureus NADPH-dependent enoyl-acyl carrier protein reductase by triclosan and hexachlorophene.” Journal of Biological Chemistry. 275: 4654-9. Print.

[16] Aiello AE, Marshall B, Levy SB, Della-Latta P, Lin SX, and Larson E. “Antibacterial Cleaning Products and Drug Resistance.” Emerging Infectious Diseases. 11(10): 1565–1570. Print.

[17] Levy SB. “Antibiotic and antiseptic resistance: impact on public health.” Pediatr Infect Dis J. 19(10 Suppl):S120-2. Print.

[18] Yazdankhah SP, Scheie AA, Hoiby EA, Lunestad BT, Heir E, Fotland TO, Naterstad K, and Kruse H. “Triclosan and antimicrobial resistance in bacteria: an overview.” Micrb Drug Resist. 12(2):83-90. Print.

[19] Davies AJ and Maillard JY. “Bacterial adaptation to biocides: the possible role of ‘alarmones’.” J Hosp Infect. 49(4):300-2. Print.

[20] SCCS (Scientific Committee on Consumer Safety), Preliminary opinion on triclosan antimicrobial resistance. March 23, 2010. European Commission, Brussels.

[21] Adolfsson-Erici M, Pettersson M, Parkkonen J, and Sturve J. “Triclosan, a commonly used bactericide found in human milk and in the aquatic environment in Sweden.” Chemosphere. 46(9-10):1485-9. Print.

[22] Allymr M, Adolfsson-Erici M, McLachlan MS, and Sandborgh-Englund G. “Triclosan in plasma and milk from Swedish nursing mothers and their exposure via personal care products.” Sci Total Environ. 372(1):87-93. Print.

[23] Greenpeace and WWF. A Present for Life: Hazardous chemicals in umbilical cord blood. Available online: http://eu.greenpeace.org/downloads/chem/Umbilicalcordreport.pdf.

[24] Chalew TE and Halden RU. “Environmental Exposure of Aquatic and Terrestrial Biota to Triclosan and Triclocarban.” J Am Water Works Assoc. 2009;45(1):4-13. Print.

[25] Higgins CP, Paesani ZJ, Chalew TE, Halden RU, and Hundal LS. “Persistence of triclocarban and triclosan in soils after land application of biosolids and bioaccumulations in Eisenia foetida.” Environ Toxicol Chem. 2011 Mar;30(3):556-63. Print.

[26] Prosser RS, Lissemore L, Solomon KR, and Sibley PK. “Toxicity of biosolids-derived triclosan and triclocarban to six crop species.” Environ Toxicol Chem. 2014 Aug;33(8):1840-8. Print.

[27] Adolfsson-Erici M, Pettersson M, Parkkonen J, and Sturve J. “Triclosan, a commonly used bactericide found in human milk and in the aquatic environment in Sweden.” Chemosphere. 46(9-10):1485-9. Print.

[28] EWG’s Skindeep Database. Triclocarban. Available online: http://www.ewg.org/skindeep/ingredient/706622/TRICLOCARBAN/ Accessed June 22, 2015.

[29] EPA. Frequent Questions Associated with the RED. Available online: http://www.ewg.org/skindeep/ingredient/706622/TRICLOCARBAN/ Accessed June 23, 2015.

[30] Wood A. 2005. FDA Non-Prescription Drugs Advisory Committee. Available online: http://www.fda.gov/ohrms/dockets/ac/cder05.html#NonprescriptionDrugs. Accessed November 5, 2013.