I’ve heard that the CDC Biomonitoring Study is measuring for triclosan in urine.
With repeated exposure to triclosan containing products, a low steady-state plasma level of triclosan can be reached after approximately 7 to 10 days.  However, once steady-state is reached, no further increases in plasma triclosan levels occur. Based on data from human studies ranging from 7 days to 52 weeks, there was no accumulation of triclosan levels as reflected in comparable plasma levels over the time course of each study, suggesting a lack of evidence of bioaccumulation.  After cessation of product use, the elimination half-life varies from several hours to a few days.  The predominant route of excretion for triclosan is the urine. Therefore it would not be surprising for the CDC to be able to measure triclosan in random samples from the population. An uptake from environmental sources (such as drinking water and crop plants) can also be safely excluded.

What does this mean for me?
For a discussion of the CDC study, please click here.

Sandborgh-Englund G, Adolfsson-Erici M,Odham G, and Ekstrand J. (2006). Pharmacokinetics of Triclosan Following Oral Ingestion in Humans.  J. Tox. Env. Health, Part A, Dec. Vol. 69 (20):1861.

Bagley D and Lin Y. (2000) Clinical evidence for the lack of triclosan accumulation from daily use in dentifrices. Am J Dent. Jun;13(3):148-52. (www.pubmed.com and enter Pub Med ID# 11763951)

I’ve heard that triclosan was found in breast milk.
Triclosan has been identified in breast milk repository samples at up to 300 micro grams/kg lipid. However, these low levels are similar to the levels of numerous other substances found in breast milk, such as garlic, vanillin, alcohol, caffeine, ibuprofen, aspirin, acetaminophen, and antacids. The triclosan concentrations measured are several thousand times lower than levels proven safe for human intake. Therefore, the concentrations of triclosan reported in breast milk do not harm either mothers or breast-fed infants. These trace levels likely occur as a result of intended use of cosmetic products containing triclosan and not from environmental contamination. In its 2002 review of triclosan, the European Commission’s Scientific Steering Committee concluded that any triclosan absorbed by the body is rapidly excreted and no long-term or large-scale accumulation occurs.

Dayan A. (2007) Risk assessment of triclosan [Irgasan®] in human breast milk. Food and Chemical Toxicology. Vol. 45 (1):125-129.

Allmyr M, Adolfsson-Erici M, McLachlan MS, Sandborgh-Englund G. (2006) Triclosan in plasma and milk from Swedish nursing mothers and their exposure via personal care products. Sci Total Environ. Dec 15; 372(1):87-93.

Adolfsson-Erici M,Pettersson M, Parkkonen J and Sturve J. (2001) Triclosan, a commonly used bactericide found in human milk and in the aquatic environment in Sweden. Chemosphere Vol 46 (9-10):1485-1489.

I’ve heard that triclosan can form chloroform when mixed with chlorinated tap water.
Under the exaggerated conditions researchers were able to measure chloroform released from both triclosan-free products as well as triclosan containing products. Based on the study designs and results, one can only conclude that the amounts of chloroform potentially generated from the personal care products have little significance and do not reflect real world use. This is substantiated in recent work in which the use of Colgate Total® was demonstrated to not result in the formation of detectable chloroform levels over the range of expected consumer-brushing times while using normal chlorinated drinking water.  

In addition, a significant point overlooked in the paper is a factual discussion of chloroform exposure levels in a risk context. The amount of chloroform generated under the worst-case conditions assumed in the Vikesland paper is well below the level which is regarded as safe by the US EPA 0.01 mg/kg/day (~250 mg/year, assuming a bodyweight of 70kg, US EPA IRIS RfD).  

Hao Z., Parker B., and Knapp M. (2007) In vitro stability of triclosan in dentifrice under simulated use condition. Int. J Cosm. Sci. Vol.29(5):353–359.

Letter to: Dr. Gerald Schnoor, Editor in Chief, Environmental Science & Technology
Click here

Chlorine and Triclosan: Overstated Risk

Rule, K.L., Ebbett, V.R., Vikesland, P.J. (2005). Formation of chloroform and chlorinated organics by free-chlorine-mediated oxidation of triclosan. Environ. Sci. Technol., 39(9), 3176-3185.

Fiss, E. M.; Rule, K. L.; Vikesland, P. J. (2007) Formation of Chloroform and Other Chlorinated Byproducts by Chlorination of Triclosan-Containing Antibacterial Products Environ. Sci. Technol.; 41(7); 2387-2394

Correction to: Fiss, E. M.; Rule, K. L.; Vikesland, P. J. (2007) Formation of Chloroform and Other Chlorinated Byproducts by Chlorination of Triclosan-Containing Antibacterial Products Environ. Sci. Technol.; 41(7); 2387-2394 published in Environ. Sci. Technol.; Vol 42 (3) (2008)-1 year later.

I’ve heard that triclosan has endocrine and/or anti-androgenic effects.
Generic statements regarding triclosan and the endocrine system have lead to significant misinformation regarding triclosan safety. The human body, and that of animals, is regulated by a complex endocrine system. A hormone is a generic term for one of the body’s many chemical messengers. There are about 15 different hormone systems in the body that make up the endocrine system, each with specific chemical messengers (eg, insulin, testosterone, and melatonin) and receptors (eg. pancreas, testes, and the brain).  

Recent research has looked at the effect of triclosan on thyroid hormone receptors in the thyroid gland of bullfrogs (Rana catesbeiana), at blood serum concentrations of the thyroid hormone, thyroxine (T4), in weanling rats and at testosterone induced transcriptional activity in cell culture experiments using mechanistically-derived cell-based assay systems. Based on the species chosen or the methods used in conducting the study, each of these studies raise questions as to the significance of the findings and if there is real world association of the findings to humans and animals.

Triclosan: No Effect on Frog Metamorphosis: The results of a new study indicates that environmentally-relevant triclosan concentrations do not alter the normal course of thyroid-mediated metamorphosis in the standard anuran model(order of frogs and toads). The Research is to be presented at the Society of Environmental Toxicology and Chemistry (SETAC) meeting in Warsaw 25-29 May 2008. To review the abstract click here.

It is indeed clearly confirmed by a wealth of scientific data including a number of multi-generation reproduction and developmental (teratology) studies that triclosan has no anti-androgenic or androgenic affects whatsoever on living organisms. In addition, study results in whole animal models show no effect on thyroid function from exposure to triclosan. These data, from 14-day exposures to lifetime studies (1 or 2-years) using validated test methods, demonstrate that triclosan does not adversely impact normal endocrine organs or their functions; does not interfere with normal reproduction; does not interfere with normal developmental processes, and support its safe use in oral care, personal care and home care products.