Triclosan and Triclocarban: Exposures, Toxicity and Testing
Plus Rolf Halden’s Interview and Upcoming Presentation at EHS 2020
Triclocarban (3,4,4′-trichlorocarbanilide; TCC) and triclosan (5- chloro-2-(2,4-dichlorophenoxy)phenol; TCS) are antimicrobial additives used in personal care products and over 2,000 other consumer products. For the purposes of this article we’ll use triclosan to refer to them both unless the research differs.
Triclosan, a commonly used biocide (also called an antimicrobial or sanitizing agent) is one of the top 10 aquatic pollutants found in the United States. In 1999-2000, triclosan was found in 57.6% of 139 U.S. streams sampled in 30 states.[1]
The CDC estimates that 75% of the U.S. population has detectable levels of triclosan in their urine.
Rolf Halden PhD started studying the immunotoxicology of triclosan and triclocarban in the early 2000’s. An expert in the field, Dr Halden will be talking about this more in depth at the Environmental Health Symposium (EHS) on April 4, 2020.
Check out this interview in the Integrative Medicine: A Clinician’s Journal (IMCJ) to learn more about his upcoming talk.
Exposure
In 2016, the US Food and Drug Administration banned the use of triclosan in hand sanitizers because the manufacturer was unable to provide adequate proof that the product was safe and because hand sanitizers are regulated as drugs, the FDA had the ability to pull these specific triclosan-containing products off the market. Triclosan, however, still remains in more than 2,000 consumer products. Triclosan can be found in personal care products in high concentrations such as toothpaste, mouthwash, and soaps.
Colgate Total toothpaste contains 10 mM of triclosan and is used widely by the public (it was the number two leading toothpaste in sales in the US in 2016). And despite the use of triclosan in surgical soaps, triclosan-containing soap products have not been found to provide any additional skin-sanitizing benefits compared to washing with warm water and soap not containing triclosan.[2]
Triclosan is also incorporated as MicrobanTM in sportswear, footwear, shower curtains, bedding, cutting boards, food containers and outdoor gear to prevent bacterial growth and odors that it causes. Triclosan can be dermally absorbed from clothing, especially with perspiration.
The European Food Safety Authority (EFSA) is the equivalent to the FDA in the European Union and banned triclosan from all human hygiene biocidal products in 2017 because the manufacturers were not able to demonstrate, to EFSA’s satisfaction, that triclosan was actually safe.
For a list of all products containing triclosan visit Environmental Working Group’s website on Where is Triclosan still approved for use?.
Another exposure is drinking water. Triclosan has been found in some drinking water sources above the estimated acceptable daily intake of 0.17 nmol/kg/day.[3] To learn more about triclosan and other drinking water contamination, watch Anne Marie Fine NMD and Tina Beaudoin ND present on Drinking Water: Fountain of Aging and Disease at the National Association of Environmental Medicine 2019 conference.
Toxicity
There is evidence that triclosan may cause:
Eczematous rash: When the part of the skin exposed to triclosan is also exposed to sunlight, photoallergic contact dermatitis may occur. This photosensitivity can cause an eczematous rash, usually on the face, neck, the back of the hands, and on the sun-exposed areas of the arms. [4],[5]
Estrogen, androgen and thyroid disruption: Triclosan is an estrogen, androgen and thyroid-disrupting chemical.[6]
Inhibition of phase II detoxification: Triclosan has been shown to inhibit metabolism and elimination of the endocrine disruptor BPA, BPS and BPF. (BPS and BPF have been used as replacements in “BPA-free” products but are themselves endocrine disruptors).[7]
Type 2 diabetes: A US 2020 study looking at 900 individuals from the NHANES 2013-2014 cohort found that in women, the odds for type 2 diabetes were 1.79 times higher if their urine triclocarban levels were detectable.[8]
Colonic inflammation: A 2018 study showed that exposure to levels of low-dose triclosan (comparable to daily human exposure) has the ability to worsen colonic inflammation and exacerbate the development of colitis-associated colon tumorigenesis in animal models.[9]
Cellular DNA damage: Cell based studies show that triclosan acts as a pro-oxidant, cytotoxic and carcinogenic compound and raises 8 OH-dG levels, indicating cellular DNA damage.[10]
Antibiotic resistance: Triclosan use has also been shown to increase risk for antibiotic resistance, by promoting the growth of small colony variants (mutant bacteria) that lead to MRSA .[11]
Microbiome damage: In a human study, use of a triclosan-containing toothpaste increased the relative abundance of broadly antibiotic-resistant Proteobacteria species in adults, as well as in infants with high urinary concentrations of triclosan.[12]
Testing
Several clinical laboratories measure urinary triclosan, including Genova Diagnostics Laboratory, and Vibrant America Labs. According to the CDC, the 95th percentile (top 5%) level of triclosan in the US population for 2013-2014 was 358 mcg/gm creatinine. This closely correlates with levels of urinary triclosan associated with daily use of triclosan-containing toothpaste in the mothers of the mother/infant microbiome study.[12]
Drinking Water Filtration
Drinking water filtration systems can remove triclosan. Simple activated carbon filtration or ultra-violet light irradiation removes 95% of triclosan. Reverse osmosis is also effective at total removal of triclosan as is.[13]
To learn more about Triclosan, attend Environmental Health Symposium 2020 Conference where Rolf Halden will talk about “Hiding in Plain Sight: Triclosan and Triclocarban as Immunotoxicants”.
References
[1] Kolpin DW, Furlong ET, Meyer MT, Thurman EM, Zaugg SD, Barber LB, et al. Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000: a national reconnaissance. Environ Sci Technol 2002;36(6):1202-1211.
[2] Halden RU. On the need and speed of regulating triclosan and triclocarban in the United States. Environ Sci Technol. 2014;48:3603–3611.
[3] Blanset DL, Zhang J, Robson MG. Probabilistic estimates of lifetime daily doses from consumption of drinking water containing trace levels of N, N -diethyl-meta-toluamide (DEET), triclosan, or acetaminophen and the associated risks to human health. Hum Ecol Risk Assess. 2007;13:615–631.
[4] Wong CS, Beck MH. Allergic contact dermatitis from triclosan in antibacterial handwashes. Contact Dermatitis. 45(5): 307.
[5] Perrenoud D. 1994. Frequency of sensitization to common preservatives in Switzerland. Contact Dermatitis 30: 276-279.
[6] Weatherly LM, Gosse JA. Triclosan exposure, transformation, and human health effects. J Toxicol Environ Health B Crit Rev . 2017;20(8):447–469. 1399306.
[7] Weatherly LM, Gosse JA. Triclosan exposure, transformation, and human health effects. J Toxicol Environ Health B Crit Rev. 2017;20(8):447–469. 1399306.
[8] Xie X, Lu C, Wu M, et al. Association between triclocarban and triclosan exposures and the risks of type 2 diabetes mellitus and impaired glucose tolerance in the National Health and Nutrition Examination Survey (NHANES 2013-2014) Environ Int. 2020;136:105445. doi:10.1016/j.envint.2019.105445]
[9] Sanidad KZ, Xiao H, Zhang G. Triclosan, a common antimicrobial ingredient, on gut microbiota and gut health. Gut Microbes. 2019;10(3):434–437.
[10] Ma H, Zheng L, Li Y, et al. Triclosan reduces the levels of global DNA methylation in HepG2 cells. Chemosphere. 2013;90(3):1023–1029.
[11] Seaman PF, Ochs D, Day MJ. Small-colony variants: a novel mechanism for triclosan resistance in methicillin-resistant Staphylococcus aureus. J Antimicrob Chemother. 2007;59(1):43–50.
[12] Ribado JV, Ley C, Haggerty TD, Tkachenko E, Bhatt AS, Parsonnet J. Household triclosan and triclocarban effects on the infant and maternal microbiome. EMBO Mol Med. 2017;9(12):1732–1741. doi:10.15252/emmm.201707882
[13] Lee DG. Removal of a synthetic broad-spectrum antimicrobial agent, triclosan, in wastewater treatment systems: A short review. Environ. Eng. Res. 2015; 20(2): 111-120