Am I killing myself through my hair?

Sodium Laurel (and Laureth) Sulfate are the topic of the day. A week ago I happened to catch the Oprah show as they were doing an Earth Day segment on hygiene and beauty products, and the chemicals used in common products. They brought up a number of issues (some of which I hope to post about at a later date) but one in particular piqued my interest. It's about Sodium Laurel Sulfate. Oprah's green guru pointed out this is an ingredient used in almost every toothpaste, shampoo and other product where foaming occurs. They cautioned to stay away if possible.

So the next time I was in my shower I peeked at my ingredient list for my Dove shampoo and sure enough, there was SLS as the second ingredient. Then I was dismayed to grab Delaney's Aveeno hair and body wash and see it as the second ingredient. I looked at the front of the bottle and noticed it was promoting itself as a "natural" shampoo and soap. Yikes! I reached for my other set of shampoo and conditioner and was pleased to see that my Giovanni shampoo did not have any SLS ingredient listed. I was now more curious than ever because the Giovanni shampoo foams up just as well as my Dove shampoo. So I decided before I started panicking about the idea that I was killing myself by washing my hair every day, I should do more research.

Here is what I learned.

Sodium Laurel Sulfate is a "sulfactant," which is essentially an agent that helps water be more effective. It is created by joining sulfate and lauric acid, two compounds widely found in nature. As mentioned previously it is what creates the foam in your products. From what I could learn there is a myth going around that says that SLS and it's cousins cause cancer. Sodium Laurel Sulfate is one form, Sodium Lauryl Sulfate is another, as well as Sodium Laureth Sulfate.

I learned that these cautions against SLS were likely started by a natural products company and that the reason they can make this claim is that SLS is often used as an ingredient or component of cancer experiments. However it seems like this link was made without counting that SLS is what is being used to solubilize OTHER ingredients and is mixed before it is injected into animals or tested on humans. In other words they weren't doing tests to see if SLS was causing cancer, and instead it was an agent used to help experiments to learn about other ingredients.

The American Cancer Society has posted a number of items debunking the cancer link with SLS, one of which can be found here:
http://www.cancer.org/docroot/NWS/content/NWS_2_1x_Debunking_the_Myth.asp

One claim made by anti-SLS websites is that sodium lauryl sulfate is carcinogenic because it produces nitrosamines when it reacts with formaldehyde. From what I could find, and you can do more searching if you like, it seems like this is chemically impossible due to the fact that neither compound contains a nitrogen atom (thus making it possible to create a nitrosamine).

It has been proved that SLS is an ingredient which causes skin irritation. But in most instances it's in very high quantities and in higher quantities than you would see in your daily hygiene products.

I visited a number of sites that will scare the piss out of you in regards to SLS and make you want to pour out every product you own that possesses it as an ingredient. A few of those can be found here:
http://www.healthy-communications.com/slsmostdangerousirritant.html
http://www.natural-health-information-centre.com/sodium-lauryl-sulfate.html

Then I visited some great sites that tried to look at both sides of the argument, found here:
http://www.tomsofmaine.com/toms/ifs/sls.asp
http://www.treasuredlocks.com/noname7.html
http://www.treehugger.com/files/2007/07/common_ecomyth_sls.php

Also most interesting is that this has made it all the way to Snopes, a site I visit regularly when someone emails me some crazy claim about some consumer product killing humans or pets. They have debunked the cancer link as well.
http://www.snopes.com/inboxer/household/shampoo.asp

So what is the take away from all of my research? It seems like high concentrations of SLS or any of it's cousins are not good for your skin and not enough research has been done yet to determine if there is any cancer link (really no research). My guess is that the concentrations we use on a daily basis are probably ok and won't kill me.

HOWEVER... I think I will be more wary of seeing where SLS falls into the ingredient list and if I can find a comparable shampoo that lists it as an ingredient further down the list, it seems like it would be wise to lower the concentrations whenever possible.