Wednesday, February 11, 2009

Triclosan - the secret pesticide

Guest post by Toxic Free NC volunteer Amy Freitag.

Ever wonder what makes "antibacterial soap" antibacterial? Since the 1960’s, triclosan is often the active ingredient, working to keep you healthy and safe.

Or is it?

Triclosan is actually a pesticide that should be handled as the dangerous chemical it is. And yet, it can be found in regular old hand soap, and a whole mess of other consumer products.....pretty much everywhere! Just take a look at this list of places triclosan is commonly found:
- cosmetics
- children’s toys
- toothpaste
- plastic utensils
- deodorant
- shoes
- mops
- kitchen accessories
- bedding
- mattresses
- food storage containers
- sponges
- phones

Triclosan is considered nontoxic to humans because large doses are necessary to show negative effects. However, a few cases have been reported where ordinary daily use of a product containing triclosan caused the skin become photosensitive and break out in a rash. According to the CDC, the chronic effects of triclosan exposure can include interfering with thyroid hormone metabolism, which could cause hypothermic effects and central nervous system depression. Research has also shown that triclosan is a major contributor to antibiotic resistance because of the specific mechanism it uses to kill bacteria, and its widespread use in almost every household and workplace.

How does it work? According to General Chemistry Online, the molecule enters the cell and binds to an important bacterial enzyme called the enoyl-acyl carrier protein reductase, which is crucial to the production of fatty acids needed for building cell membranes and molecules for communication. What all that chemistry boils down to is basically that triclosan gums up the keyhole necessary to lock the cell up, leaving the bacteria wide open, like a house in a bad neighborhood with the front door hanging open. However, all it takes for the bacteria to escape this bad fortune is to alter the keyhole a bit so that the triclosan can’t fit. Once one figures out how to do this, it survives to reproduce a population of resistant bacteria.

Although it may be less than totally effective at killing the offending germs that cause illness, triclosan and related antibiotics are highly effective at wiping out entire populations of natural, healthy bacteria that are necessary for the ecosystem and even human health. By removing the normal bacterial flora from our environments, we aren’t exposed to normal parts of the ecosystem, and then when we finally are, the result may be.... achoo! Seriously, one theory of allergy formation is that exposure to bacteria (within reason, of course) is actually a normal and necessary part of developing a healthy immune system.

As for the ecosystem, those bacteria fill niches in food webs, nutrient cycling, and disease resistance that contribute to the resilience of the environment in the face of threats such as global warming and development. The story with algae in streams and rivers is similar – they show drastic negative effects in the presence of triclosan, often downstream of wastewater treatment plants that don’t treat for pharmaceuticals. These algae provide the base of the aquatic food web that supports the entire system. If we remove that protection through our use of hand soap, we exacerbate the other environmental problems humans have come to bear on earth.

As if that all weren't bad enough, triclosan itself is not the only threat associated with triclosan use. How, you might ask? When exposed to sunlight, triclosan converts into carcinogenic dioxins. Research on the effects of triclosan and metabolites such as dioxin is still ongoing, which begs the question why the chemical is allowed to be so widely used without full knowledge of its impacts. That is a policy question that could take a book to analyze the answer to, but the future of these effects is in the hands of the consumer at this point.

So, convinced you want to avoid this ubiquitous chemical? Good luck! Heres's a "cheatsheet" with tips on avoiding products with triclosan from Environmental Working Group. It's a lot of information to digest, but there are two main changes you can make quickly and easily that will help a lot:

1) Wash your hands with good old fashioned soap and water. According to an epidemiology group out of the University of Michigan, it's the best way. The FDA is also beginning to figure this out, finally.

2) Read ingredient labels for soaps and cosmetics. Don't buy stuff that lists triclosan or the closely-related triclocarban.

No matter what type of soap you use, most germs are removed from your hands by the simple act of wiping them off. Soap and water help a lot, but you don’t need to go beyond that. If the germies are already off your hands and down the drain, does it really matter if they're also dead? For regular handwashing and personal hygiene, the relative ineffectiveness of antibacterial products combined with the very real threat of antibiotic resistance from their over use mean that antibacterial soaps could actually be doing more harm than good.

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