Triclosan: The All Purpose Anti__?


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This is what Triclosan looks like from a chemistry perspective. Image courtesy of NIH.

Triclosan, an antibacterial agent, has been in use since prior to 1963. You can find it in toothpaste and soap in US markets.

Since 1963 Triclosan has been used in hospitals and in the agriculture industry as well – it has found a niche in almost every part of the consumer market.

Triclosan History

Ciba Geigy successfully patented Triclosan in the U.S. as an antibacterial agent, and an additional patent disclosure (from 1975) reveals its potential for most major consumer products—from insecticide, fungicide to bacteriostatic and flame retardant.

The effectiveness of Triclosan as a ‘scrub’ is not the issue. The problem is that this substance is an environmental contaminant due to its persistent nature.

Triclosan has been used in every aspect of society, to a point where it shows up in urinalysis specimens for no reason.

The U.S. Food and Drug Administration is presently working with major conglomerates to ban Triclosan from all consumer products. The National Resources Defense Council sued the FDA to petition this action. So what’s so bad about Triclosan?

Triclosan: A Persistent Pollutant

Triclosan is an organic molecule whose mode of action, as an antibacterial, is to disrupt the bacterium’s metabolism. The molecule, upon inspection, has certain distinguishing features that mark it as a good candidate for biological activity:

(1). Triclosan is semi-flat.

(2). This substance possesses phenolic (alcohol-type) functional groups.

(3). Triclosan contains chlorine atoms.

(4). Triclosan possesses ‘aromatic character.’

Unfortunately, these features allow the molecule to be readily absorbed through the skin and deposit into the fatty tissues of the body as well.

The characteristic features of this chemical, when taken as a whole package, are reminiscent of another molecule: hexachlorophene (which was banned from consumer use in 1970s). Like Triclosan, hexachlorophene was used as a scrub in surgical rooms and was utilized in consumer products like Phisohex.

The allure of Phisohex to the consumer was that it contained no phosphate detergents but it was as effective as any phosphate scrub that had been on the consumer shelf up that point. Ultimately its U.S. ban came from its use in talcum powder which had led to the deaths of infants in France.

Where is Triclosan?

Courtesy of NIH, Hexachlorphene

This is a model of hexachlorophene. Image courtesy of NIH.

Triclosan is an organic molecule which has been in use for decades; it is presently found throughout Earth’s biosphere.

The molecule has a tendency to bind to clay-type soil and is found at the bottom of fresh water streams and lakes.

Triclosan has been used as fire retardant in forest settings and the purported half-life for Triclosan (the length of time that ½ of the original material decomposes) may be greater than 90 days. In some circumstances, in low oxygen environs, the half-life may be longer.

Hexachlorophene and triclosan also share another distinction, the molecules form dioxin-type species when irradiated with UV light. The dioxin-type molecules owe their distinctiveness to the environmental crisis of Times Beach, MO, and Love Canal, NY in the 1970s.

Once the molecule finds its way into the soil, it tends to accumulate in the root and leaves of plants. Taking it to the next logical step would put the molecule into the gut of whatever animal eats the plant.

Triclosan: Throughout the Food Chain

Studies on rats that have ingested triclosan-laden plants indicate that the molecule will translocate from their gut to their fatty tissue (such as the liver). The major reason for translocation is the fat-loving character of the molecule. The molecule is mainly carbon in structure, so it will readily dissolve in organic-type species (e.g. fatty tissue). In studies of pregnant rats, the placenta and breast milk contained significant amounts of Triclosan.

In other research developments, the native frog populations throughout the Western U.S. have been threatened with the development of extra sets of hind legs.  The researchers trace Triclosan as the cause.

Studies of fish (Fathead Minnow) ingesting triclosan indicate that the molecule disrupts estrogen and androgen pathways; resulting in poor locomotion. The affected minnow become easy prey and it results in a poisoning effect throughout the food chain.

Triclosan: A Non-Outcome?

As a result of the NRDC’s lawsuit, companies that presently use Triclosan in their consumer products must find a suitable replacement by 2015. For consumers in the U.S. the use of Triclosan has turned into one of the worst breaches of trust in recent memory.

The breadth and scope in which Triclosan has found use and misuse may  signal to consumers that efforts of government to shield them from harm has been a failure.

Whether new regulations result from the debacle or an equally troubling chemical is called into service is still an unknown.

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