CAS No. 3380-34-5
Triclosan, a phenolic diphenyl ether used for over 30 years as a preservative and antiseptic agent, acts by inhibiting bacterial fatty acid synthesis. Triclosan has been added to soaps, toothpastes, mouthwashes, acne medications, deodorants, and wound disinfection solutions, and has also been impregnated into some kitchen utensils, toys, and medical devices. Triclosan enters the aquatic environment mainly through residential wastewaters. It can be photochemically and biologically degraded, a process that can result in the formation of small amounts of 2,8-dichlorodibenzo-p-dioxin (Aranami et al., 2007; Mezcua et al., 2004). In 1999-2000, triclosan was found in 57.6% of 139 U.S. streams sampled in 30 states (Kolpin et al., 2002). Triclosan has a low bioaccumulation potential in fish. There is some concern that widespread use of triclosan and other biocides can alter antibiotic resistance in bacteria (Aiello et al., 2007).
General population exposure results from dermal and oral use of products containing triclosan. Triclosan can remain present in the oral saliva for several hours after the use of toothpaste containing triclosan (Gilbert et al., 1987). Triclosan can be absorbed across skin into the blood stream. In the body it is conjugated to glucuronides and sulfates (Bodey et al., 1976; Moss et al, 2000). In animal and human studies, it is excreted over several days in the feces and urine as primarily as unchanged triclosan (Kanetoshi et al., 1988; (Sandborgh-Englund et al., 2006).
Human health effects from triclosan at low environmental doses or at biomonitored levels from low environmental exposures are unknown. Triclosan formulations may rarely cause skin irritation. In animal studies, it has low acute toxicity. Some reports show endocrine effects are observed in amphibians and fish (Foran et al., 2000; Matsumura et al., 2005; Veldhoen et al., 2007). Triclosan is not considered teratogenic at maternally toxic doses, and has not been considered mutagenic or carcinogenic (Bhargava and Leonard, 1996; Lyman and Furia, 1969). IARC and NTP do not have ratings with respect to human carcinogenicity.
Urinary triclosan levels reflect recent exposure. In a U.S. representative subsample of NHANES 2003-2004, Calafat et al., 2008 found higher levels during the third decade of life and among people with the highest household income, but not by race/ethnicity and sex. In a study of 90 U.S. young girls, the median urinary triclosan level of 7.2 µg/L was comparable to the median level (8.2 µg/L) of children 6-11 years of age who participated in NHANES 2003-2004 (Wolff et al., 2007; Calafat et al., 2008). Over the NHANES 2003-2010 survey periods, urinary triclosan levels appear to be generally similar across the age, sex, and racial/ethnic demographic groups (CDC, 2012).
Finding measurable amounts of triclosan in the urine does not imply that the levels of triclosan cause an adverse health effect. Biomonitoring studies on levels of triclosan provide physicians and public health officials with a reference values so that they can determine whether people have been exposed to higher levels of triclosan than are found in the general population. Biomonitoring data can also help scientists plan and conduct research on exposure and health effects.
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