Hitting the innerwaves today, care of ES&T,  is an article on EPA’s approval of Triclosan.   Triclosan is found in a large number of consumer products (e.g.  soaps, detergents, deodorants, mouth wash, and toothpaste).  Colgate Total, for example, contains triclosan to prevent gingivitas.

Triclosan is an antibacterial that binds to an enzyme in bacteria that is used to build fatty acids, a necessary component in bacterial cell membranes.    Notice, I said that it is an antibacterial and not an antibiotic.

Triclosan’s efficacy in hand soap is debatable.  Some studies have shown that hand washing is not improved with the addition of triclosan, if the recommended 30 second social hand wash is followed.  Others contend that triclosan provides a residual on the hands that continues to work against bacterial contamination, useful in settings where people do not wash their hands completely or correctly.  Most consumer products, like cutting boards, table tops, and children’s toys, that bear the term antibacterial likely have triclosan imbedded in the surface.

Additionally, soap with high concentrations of triclosan (think 2% compared to the 0.5% found in consumer soaps) are used to decontaminate individuals exposed to MRSA.

So why is it news that the EPA extended triclosan’s approval?

1) There is some (ok, very little) concern about antibacterial resistance developing, which seems unlikely unless organisms currently resistant (such as P. aeroginosa) are able to transfer resistance to other species.

2) Triclosan degrades in sunlight to form byproducts in a class of compounds known as Dioxins, which bioaccumulate in fatty tissue and pose a threat to the reproductive, sexual development, and immune systems and are probable carcinogens.  With household use sending triclosan directly down the drain to the waste water treatment plant, it frequently ends up in surface waters where it becomes an environmental pollutant.

and 3) The ES&T article mentions, through Cathy Propper at NAU, that triclosan bioaccumulates and impacts nitrogen fixation in microbial communities and plants.

My take?  Totally not necessary.  Just wash your hands well.  Wash your cutting board well.  Your table top…  Why contribute to a problem we have no idea of the magnitude of for the sole benefit of maybe, possibly, protecting ourselves environmental bacteria?

We’ll see what the EPA says when it comes up again in 5 years…