Connie Tang – The Green Chemistry Initiative Blog

By Connie Tang, Member-at-Large for the GCI

Triclosan: it’s in your soap, body wash, and your toothpaste. It can be even found in yoga mats.

Triclosan is an antibacterial agent added to household products. While soap is rarely the centre of a news story, triclosan has garnered significant controversy after the United States Food and Drug Administration (FDA) banned these potentially hazardous chemicals (along with 18 others) from hand soaps.¹ Meanwhile, Canada has labelled the chemical as toxic for the environment, and maintained that it does not meet the standard for human health toxicity.²

What is triclosan and where is it beneficially used?

Antibacterial soaps (also known as antimicrobial or antiseptic soaps) contain additional chemicals with the intent of reducing bacterial infection. Triclosan is one of these chemicals and is often used in personal care products, cosmetics, and can even be found in toys, kitchenware, and furniture. In the past two decades, its use has expanded commercially and by the year 2000, triclosan was found in 75% of liquid soaps and almost 30% of bar soaps.³

Antibacterial agents, like triclosan, were originally used in surgical scrubs and hand washes to protect health workers in medical settings from bacteria that can cause infections in hospitals. In surgical units, triclosan is effective against bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), which is resistant to most antibiotics.

Additionally, triclosan can be found in toothpastes, because it has been linked to improved protection against cavities.

In 2008, the Environmental Working Group (EWG) found high levels of triclosan in San Francisco Bay, which prompted studies of this chemical in blood and urine samples of teenage girls to explore its impact on endocrine hormonal processes. Since 2008, the EWG has been submitting reports to the FDA to ban triclosan in personal care products.⁸

Is triclosan dangerous?

Short answer: Triclosan is most likely harmful to the environment, and possibly harmful to humans.

Environment Canada has categorized triclosan as potentially toxic to aquatic organisms since it bioaccumulates (becomes more concentrated). Even at low concentrations in aquatic plants and animals, it can cause growth reduction and decreased reproduction, impacting survival. Triclosan’s structure is similar to thyroid hormones, so scientists have suggested triclosan’s mechanism of toxicity might involve binding to hormone receptors, impacting hormone functions.⁴

Animal studies with triclosan have shown that mice exposed to antibacterial ingredients were more likely to develop liver cancer.⁸ Another study exposed triclosan to pregnant rats⁹ and found their hormone (progesterone, estradiol, testosterone) levels dropped, potentially affecting fetal development. Triclosan can interfere with normal thyroid hormone functions,¹⁰ raising concerns about reproductive impacts. However, no definitive study has proven how harmful triclosan is to humans.¹¹

Triclosan is also persistent, meaning that it does not degrade easily.¹² Once it is washed down the drain, most wastewater treatment plants cannot effectively filter out triclosan, and it enters our Great Lakes and waterways.

Lab studies with triclosan suggest it can randomly generate mutations in bacteria.¹³ This will likely lead to increasing antibiotic resistance in bacteria, creating “superbugs” and decreasing the effectiveness of antibiotics.

Why was triclosan (one of 19 active ingredients) banned in soaps by the FDA?

The FDA banned triclosan and other ingredients from soaps, because there is no compelling evidence the ingredients are safe.¹ In 2013, the FDA asked manufacturers to submit evidence that antibacterial ingredients are safe for long-term use and more effective than regular soap at reducing the spread of germs. Neither was proven. Resulting research suggested triclosan and similar agents might be harmful.

“Consumers may think antibacterial washes are more effective at preventing the spread of germs, but we have no scientific evidence that they are any better than plain soap and water,” said Dr. Janet Woodcock, director of the FDA’s Centre for Drug Evaluation and Research in a press release.¹

While triclosan is useful in medical settings to protect against bacteria like MRSA, it is not necessary in consumer soaps. So, this ban applies to consumer products, not to antibacterial soaps used in hospitals and food service settings. Products not under the purview of the FDA (like toys, furniture, apparel) are not subject to the ban.

What is Canada’s response?

Health Canada has restricted the amounts of triclosan in mouthwash and personal care products, but has not banned the chemical.² While concentration limits of triclosan are low (0.03% in mouthwashes, 0.3% in cosmetics),⁵ even these small amounts will bioaccumulate in our aquatic ecosystems.

The Canadian government has announced that triclosan is not hazardous to human health, but has declared it toxic under the Environmental Protection Act because of its negative effect on aquatic organisms. Environment Canada has flagged triclosan for future assessment.⁶

Health Canada has said, “The health and safety of Canadians is of utmost importance… The government will continue to monitor new scientific evidence related to triclosan and will take further action if warranted.”

Canada does plan to introduce measures to limit the release of triclosan from consumer products into waterways.⁶ But this may prove more challenging as this requires manufacturers to develop plans and upgrade for waste-treatment equipment – a costly endeavor.

Many environmentalists and scientists are pushing for Canada to implement a ban of these chemicals in consumer products. In the meantime, should we, as Canadian consumers, refrain from buying antibacterial soaps?

“It really should not be left to the consumers to try to avoid these products, especially given that there is very little benefit to using them,” says Fe de Leon, Canadian Environmental Law Association researcher.⁷

References

Triclosan laboratory studies

Feng, Y.et al. PLoS ONE 11(5).
Yueh, M. F. et al. Proc Natl Acad Sci U S A 2014, 111(48), 17200.
Gee, R. H. et al. Appl. Toxicol. 2008, 28, 78.
Calafat, A. M. et al. Health Perspect. 2008, 116(3), 303.
Ricart, M. et al. Toxicol. 2010, 100(4), 346.
Pycke, B. F. G. et al. Appl. Environ. Mircobiol. 2010, 76(10), 3116.