Q. I've heard that we should avoid sodium laurel sulfate in shampoo because it's toxic, so I buy shampoo that’s "SLS-free,” but now I’ve noticed that it contains something called sodium coco sulfate instead. Is this actually a better alternative or just an example of green-washing? – James, MI

A. You’re smart to wonder about this suspicious-sounding sodium coco sulfate—not only because your body is a temple, but also because we all vote (with our wallets) for better personal care product health standards every single time we make a purchase. With the Organic Consumers Association reporting that even supposedly “organic” body care lines often contain carcinogens, we know we’ve got miles to go before we sleep.

So let’s talk science. “SLS” can actually refer to two different, but similar-sounding chemicals—one of which is merely irritating and the other of which may be linked to cancer. Both are a type of surfactant, which are what allow shampoos and other detergents to suds up and clean really well, explains Sean Gray, senior analyst for the Environmental Working Group. For years, the most common surfactant was sodium laurel sulfate, or SLS. Unfortunately, it irritates lots of people’s skin, so companies started looking for ways to improve it. They started putting sodium laurel sulfate through a marvelous process whereby it becomes sodium laureth sulfate, which does the same job, but without irritating skin. That’s great, right?

Wrong. This marvelous process leaves behind two chemicals, ethylene oxide and 1, 4-dioxane, both of which are, you guessed it, carcinogens. Talk about cutting off your nose to spite your face. Anyway, both the skin irritation problems associated with sodium laurel sulfate and the potential cancer risks associated with sodium laureth sulfate (which can be called either SLS or SLES) have lead to a profusion of “SLS-free” and “SLES-free” shampoos and other sudsy products. Most of these new products use sodium coco sulfate as a replacement surfactant, which brings us, finally, to your question.

Actually, shampoo makers finally seem to have gotten it right this time. Sodium coco sulfate is a coconut derivative, and though it hasn’t been subjected to as much testing and scrutiny as have more widely-used ingredients, it does indeed seem to be a safer alternative to SLS. It’s less irritating than sodium laurel sulfate, but   doesn’t contain the cancerous byproducts of evil twin cousin sodium laureth sulfate, says Gray. So go ahead and lather up, without working yourself into a lather over SCS. Believe it or not, your shampoo sounds like a pretty safe option. Rub a dub dub, treehuggers in the tub.

Story by Sarah Schmidt. This article originally appeared in "Plenty" in December 2008.

Copyright Environ Press 2008

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