Triclosan or soap and water?

March 18, 2013 at 9:17 pm | Posted in Feature Articles | 3 Comments
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Triclosan or soap and water?

Image by XKCD (Hand Sanitizer)

What is triclosan and why is it used?

Initially used in products for its anti-bacterial and anti-mold properties, triclosan is a chemical substance (5-chloro-2-(2,4-dichlorophenoxy)phenol, CAS 3380-34-5) added to many common products. It is most associated with toothpaste, mouthwash, hand-sanitizer, soap and dish-washing detergent; however, it also crops up in toys, mattresses, clothes, medical devices and kitchen utensils. It works by blocking fatty acid synthesis in bacteria, preventing reproduction and building of cell membranes. Since humans do not have the corresponding enzyme, any toxicity has to occur via other mechanisms.

Its marketing appeal lies in its purported ability to protect people from bacterial infection and poisoning (after all, who does not want protection from bacteria?) has led to very widespread use, to the point where while US Centers for Disease Control and Prevention biomonitoring data show that while 75% of Americans have detectable levels of triclosan in their blood (CDC 2009), potential restrictions on triclosan pose a significant risk to the makers of antimicrobial and antibacterial hand soaps, a market said to be worth about $375 million (NYT 2011).

Research into hazards and effectiveness of triclosan

Despite its widespread use, only a relatively small amount of research into the potential health effects of triclosan has been published. Much of the evidence for potential harm from triclosan comes from in vivo amphibian and fish studies and in vitro mammalian studies. A recent review of the available data found little evidence of carcinogenicity, mutagenicity or developmental toxicity, though there are indications that triclosan may disrupt thyroid hormone homeostasis and possibly the reproductive axis (Dann & Hontela 2011).

A PubMed search for effects of triclosan on the thyroid system (search string: “triclosan thyroid”) yields only 27 results, of which only 12 are human research (“triclosan thyroid human”). Overall there are only 58 papers on human toxicity of triclosan in PubMed (“triclosan toxicity human”) compared with 162 for the stain-repellent PFOA (“PFOA toxicity human”) and 368 for the phthalate DEHP (“DEHP toxicity human”).

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Click image to enlarge

Results from among the 12 human thyroid function studies are conflicting. While a recent epidemiological study observed “a positive association between triclosan and total triiodothyronine (T3) concentrations in adolescents” suggesting that “triclosan exposures may be associated with altered thyroid hormone levels in humans” (Koeppe et al. 2013), a rare placebo-controlled clinical trial has found no association between use of toothpaste containing triclosan with changes in thyroid function (Cullinan et al. 2012).

There does seem to be more research into allergenicity of triclosan than any other potential health effect (a search for “triclosan allergy” in PubMed yielding 46 results), suggesting that triclosan exposure increases allergic sensitisation, with higher urinary concentrations of triclosan especially related to inhalant and seasonal allergens (Bertelsen et al. 2013, Savage et al. 2012).

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Click image to enlarge

There are also concerns that triclosan may contribute to antibiotic resistance, although evidence is again limited here, and may even be something of a red herring: if triclosan is useful in healthcare for preventing infection, then this should not be compromised by the unnecessary use of triclosan in consumer products, regardless of whether or not it produces resistance to antibiotics and other antimicrobials.

The lack of research into risks posed by triclosan seems to be mirrored by a lack of evidence for its effectiveness. Although Colgate has FDA approval to use triclosan in its Total toothpaste because of its ability to fight gingivitis, the FDA has also said that it “does not have evidence that triclosan in antibacterial soaps and body washes provides any benefit over washing with regular soap and water.” For other consumer products the FDA “has not received evidence that the triclosan provides an extra benefit to health”. (FDA 2012)

What to do?

In Europe and the US, products containing triclosan have to be labelled as such, so it is relatively easy to avoid buying it if one is so inclined. However, depending on labelling instead of regulation to protect people and the environment from exposure to triclosan is unlikely to be successful, as it makes a reduction in environmental exposure contingent on people’s buying choices. These are much more tightly linked to what people know about a product (for triclosan, this may not be much), and the availability and desirability of alternatives, than to the risks posed by the use of the agent.

A UK medical Hygienist Panel has stated that “the uses of triclosan with demonstrable health benefits, as in some medical applications (such as antimicrobial sutures), need to be distinguished from those where there is no proven benefit, such as its use in certain consumer products. The addition of triclosan to a product must be substantiated in any claim of preventive or therapeutic health benefit.” (Leaper et al. 2011)

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Click image to enlarge

The high-street chemist Boots has prohibited triclosan from use in plastic articles, clothing and similar types of goods, stating that while they “do not believe that triclosan presents a direct risk to health from its use in consumer products […] that indiscriminate use of triclosan may have put an undue strain on the environment.” Triclosan can continue to be used in cosmetic and toiletry products sold by Boots, but only where it “offers the consumer a clear benefit” (Boots 2005). Johnson & Johnson have announced plans to go further, the company saying it will phase out triclosan by 2015 (AP 2012).

Actio Corporation, a software company providing data management tools to solve supply-chain problems of material disclosure and compliance with conflicting environmental regulations found in a global supply chain, are blunt that “manufacturers see triclosan as a marketing bonus.” (Actio 2012)

Actio’s advice is to “prepare to purge the chemical from product plans”, because “when a chemical like triclosan permeates the product development and/or marketing plans of a business, substantial profits stand to be lost if that chemical turns up on a popular or agency blacklist.”

A note of caution on substituting triclosan for other biocides

Triclosan concerns are encouraging chemical substitution. Reckitt Benckiser, manufacturers of Vanish, Finish and Dettol has removed triclosan from three face washes. Colgate-Palmolive has replaced triclosan with lactic acid in Palmolive Antibacterial Dish Liquid, and its Softsoap liquid hand soap has been reformulated without the chemical.

Bearing in mind, however, the Canadian Government statement that: “In most cases antibacterial soap is not necessary for safe, effective hand hygiene. Alcohol-based hand cleansers are useful when soap and water are not available,” (Health Canada 2012) one could ask if any substitution of triclosan with an alternative biocide is in fact necessary.

The reason being, if triclosan has not contributed to antibiotic or antimicrobial resistance in bacteria, after being used for decades prior to this being investigated, then perhaps we should be counting ourselves lucky. And if we did get lucky with triclosan, why would we want to repeat the gamble with a new range of biocides which are less well-tested than the one they are replacing – especially in an age when antibiotic resistant bacteria are running out of control?

Outside the healthcare environment, the idea that extra anti-microbial ingredients might protect us from germs might be reassuring but there is little reason to think it is true, while there is at least some evidence (bearing in mind this article has not even touched on the ecotoxicity of triclosan) to think it at best constitutes an unknown but potentially serious environmental health risk with no safety pay-off. So what reason is there to use anything other than traditional soap and water?


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  1. […] is the most common ingredient in synthetic antibacterial products and has antiseptic properties.  Triclosan is a health and environmental toxin, is a chemical pollutant that persists in the environment and boiaccumlates in humans and […]

  2. […] Triclosan or soap and water? Despite its widespread use, only a relatively small amount of research into the potential health effects of triclosan has been published. Much of the evidence for potential harm from triclosan comes from in vivo amphibian and fish studies and in vitro mammalian studies. (March 2013) […]

  3. […] use appears to be declining in hand wash products – the main application of the antibacterial. (Also see H&E #57 for a detailed overview of the use of triclosan in consumer […]

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