Part 2 in everything you need to know about hand sanitisers : what is triclosan and why was it banned?

 

 

Following on from part 1 - where we took an in-depth look at some of the most asked questions surrounding hand sanitising - in this part 2 continuation we will be taking a deep dive into the science behind triclosan and exploring why this ‘question mark’ chemical is raising serious cause for concern amongst medical experts.


What is triclosan?

Triclosan, which has the chemical name 5-chloro-2-(2,4-dichlorophenoxy)phenol, is a synthetic, broad-spectrum antimicrobial agent. Functioning as an antimicrobial agent, triclosan blocks the active site of a bacterial enzyme known as enoyl-acyl carrier protein reductase enzyme. Research has proven that by blocking the active site, triclosan inhibits the enzyme, and therefore prevents the bacteria from synthesising fatty acid, which is necessary for building cell membrane and for reproducing - “When used at low concentrations, triclosan can successfully inhibit the growth of microorganisms; while higher concentrations of this chemical will directly kill microorganisms”. Since humans lack this enzyme, triclosan has been ‘generally’ accepted as harmless to human health. This general acceptance has placed triclosan, alongside a plethora of other chemicals, to be widely used as an antibacterial in many everyday products, including some plastic bottles and containers, soaps, toothpaste, mouthwash, cosmetics, and of course hand sanitisers. 

Further medical research, however, has sparked wide-spread concern amongst medical experts as “laboratory studies demonstrate that triclosan may have potential to adversely affect the bone mineral density in cell lines or in animals”.


Is triclosan safe? 

In 2016, the United States Food and Drug Administration (FDA) banned the incorporation of triclosan and 18 other antimicrobial chemicals from household soap products, adding further restrictions in the following year that prevented companies from using triclosan in all over-the-counter (OTC) healthcare products without premarket review. 

These actions were predicated upon manufacturers failing to provide conclusive proof that triclosan was safe and effective amidst new conflicting research that indicated potential hormonal effects and a long-term public health risk consistent use of triclosan presents. 

Published in the Journal of clinical endocrinology and metabolism, a study on the Association Between Urinary Triclosan with Bone Mass Density and Osteoporosis in US Adult Women found that women with higher levels of triclosan in their urine were more likely to have bone issues. The studies author, Dr. Yingjun Li of Hangzhou Medical College School of Public Health, stated “as far as we know, this is the first epidemiological study to investigate the association between triclosan exposure with bone mineral density and osteoporosis in a nationally representative sample”. Short-term animal studies have also shown unsettling results as exposure to high doses of triclosan have been linked with a decrease in levels of some thyroid hormones. However, more medical research is required and it remains unknown whether or not these findings are significant to human health. Due to this, triclosan remains permitted in the UK. 


What are the benefits of triclosan? 

When confronted with the transpiring studies surrounding triclosan and in light of the FDA’s concern to elicit a ban of triclosan in OTC healthcare products, it is unsurprising that we are left with the real question of why some companies still insist on including triclosan in their products. Most of these products will contain anywhere from 0.1% to 03% triclosan and in some cases there are instances when the incorporation of triclosan has provided antibacterial benefits. In 1997, the FDA reviewed extensive effectiveness data on triclosan in Colgate Total toothpaste - the evidence showed that triclosan in that product was effective in preventing gingivitis. Similarly, in today's market, triclosan is used as a low toxicity antibacterial agent that can be added to toothpastes to reduce inflammation of gums and aid in reducing plaque and gingivitis. 

Unfortunately, not enough study has been conducted into the toxicity of triclosan. Upon entering the human body, triclosan is rapidly metabolised into glucuronide and sulphate conjugates, which exits the body through urination. The speed of this process should eliminate triclosan’s toxicity to humans, however, its direct exposure to skin has been associated with contact dermatitis and skin irritations - an important factor when considering hand sanitising products. 


Future research 

Increasingly, medical researchers have become concerned with both the content and use of antimicrobials in every-day use. Much of the research today surrounding triclosan is suggestive of posing a future problem with long-term use. But as studies increase in exposing potential problems, to date there is currently no conclusive evidence to show that triclosan is carcinogenic or mutagenic and until more research is completed, the endocrine-disrupting chemical will surely remain as a forerunner in consumer goods and personal care products.

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