Health & Beauty Ingredients - Sodium Lauryl Sulfate
Part two of our series on different ingredients found in health & beauty products finds us foaming at the mouth... Why? We're looking at Sodium Lauryl Sulfate and Sodium Laureth Sulfate, the products that make the bubbles in your shampoo and toothpaste.
As always, the goal in these entries is not to chastise any brand(s) or to tell you which products to buy; the aim is to help you be a smarter consumer and to urge you to read the labels on health & beauty products the way you do with packaged food products.
What is it?
Sodium Lauryl Sulfate (SLS) and Sodium Laureth Sulfate (SLES) are the agents in shampoo, liquid soaps, toothpastes, etc. that cause foaming (e.g., bubbles).
Why do I care?
We want to take a look at all chemicals we put on (and in) our bodies on a daily basis, because repeated exposure can lead to build up over time. There has also been a lot of worry, especially over the Internet, about cancer risks. Lastly, SLS/SLES are considered skin irritants.
Please explain.
The general concern -- build-up over time -- is something to consider regarding all lab-created chemicals, petrochemicals and even natural-based chemicals (such as essential oils) that you expose your body to regularly. The skin is porous, especially the scalp, and components of your shampoo, toothpaste, deodorant, and soap can enter the body through the skin and mouth. The human body has several ways of getting rid of unwanted and waste products; most often, this is through the liver. If the liver can not process the chemical quickly, dangerous levels of it can build up, causing damage and clogging the process by which our body cleanses itself.
While, the Journal of the American College of Toxicology did find that some studies indicate residual levels of SLS can build up in the liver, heart and brain via the skin(1), the Cosmetics Datatbase references the Environmental Canada Domestic Substance List in categorizing SLS as "not known to bioaccumulate in wildlife or humans." Confused?
As for the cancer risk, I could find no definitive in vivo test (where the test is actually done on a living human being) showing a cancer link with SLS. Cosmetics Database quotes the Bulletin of Environmental Contamination and Toxicology from 1982 as showing "one or more in vitro tests on mammalian cells show positive mutation results." This means that 27 years ago, scientists were able to prove mutagenic cell growth in a lab dish. Most in the cosmetics industry (both traditional and watchdog groups) dismiss the cancer link. The situation gets gray with SLES. SLES is formed from SLS in a chemical process involving the presence of 1,4 dioxane. 1,4 dioxane is considered a carcinogen by the EPA, and the FDA strongly encourages -- but does not require -- manufacturers to remove it.
The biggest deal with SLS, SLES, and all of their "relations" (visit EWG's Cosmetics Database for a comprehensive list of related components) is their tendency to irritate skin. SLS/SLES are nothing more than detergents, which means they lather up great, but they remove a lot of naturally occurring skin oils: your skin and hair get dried out, and some people experience irritation or canker sores.
What's the take-home message?
Check the labels of EVERYTHING. You'll be surprised how many places and in what products SLS/SLES show up. Even products labeled "Organic" or "Natural" can contain SLS/SLES.
As stated before the purpose of these blog entries is not to label "good" or "bad"; everything must be taken in context. Can SLS cause contact dermatitis? Yes, in some people. But there are foaming agents that are far worse for you. Is a shampoo that is SLS-free "good" for you? Only if you look through the ingredient list and find it free of all the other harmful chemicals out there. Are products that contain SLS carcinogenic? I personally think the jury is out, but your position might be, "Why take chances?"
On a personal note, the toothpaste I use contains SLS. I like this toothpaste and will continue using it. On the other hand, my shampoo contains it also, and I have noticed much drier scalp and hair since using this shampoo; I will try another brand.
The last word.
Lab-created chemicals are scary; they came into our everyday life promising better quality products and healthier living. Now they are everywhere, and most of us don't know what they are, why they're there or how safe they are. Once a chemical, like SLS, is targeted, products show up everywhere advertising that they're "SLS-free." You, as a consumer, aren't given all of the information, and choosing a toothpaste becomes more confusing than your tax forms.
Read the labels on everything. I can't stress that enough. If you don't know what a chemical component is, look it up. And use several sources, because some websites have their own agenda. My best advice is, when checking the ingredient listing, if you don't know what three of the ingredients are, put the product back on the shelf. There are many companies out there that carry shampoos, deodorants, and toothpastes with easy-to-understand ingredients.
For further information on Sodium Lauryl Sulfate and Sodium Laureth Sulfate, these are some good starting points:
Wikipedia
Treehugger "Common Eco-Myth: Sodium Lauryl Sulfate (SLS) Causes Cancer" (read through the comments to see how passionate some people get about this topic)
Jason Cosmetics "Sodium Lauryl Sulfate in Shampoos, The Real Story"
Environmental Working Group's Skin Deep Cosmetic Safety Database
Wishing you much health!
(1) "Final report on the safety assessment of sodium lauryl sulfate." Journal of the American College of Toxicology; 1983; 2(7). Also quoted at http://www.jasoncosmetics.com/sodium_lauryl_sulfate.html
As always, the goal in these entries is not to chastise any brand(s) or to tell you which products to buy; the aim is to help you be a smarter consumer and to urge you to read the labels on health & beauty products the way you do with packaged food products.
What is it?
Sodium Lauryl Sulfate (SLS) and Sodium Laureth Sulfate (SLES) are the agents in shampoo, liquid soaps, toothpastes, etc. that cause foaming (e.g., bubbles).
Why do I care?
We want to take a look at all chemicals we put on (and in) our bodies on a daily basis, because repeated exposure can lead to build up over time. There has also been a lot of worry, especially over the Internet, about cancer risks. Lastly, SLS/SLES are considered skin irritants.
Please explain.
The general concern -- build-up over time -- is something to consider regarding all lab-created chemicals, petrochemicals and even natural-based chemicals (such as essential oils) that you expose your body to regularly. The skin is porous, especially the scalp, and components of your shampoo, toothpaste, deodorant, and soap can enter the body through the skin and mouth. The human body has several ways of getting rid of unwanted and waste products; most often, this is through the liver. If the liver can not process the chemical quickly, dangerous levels of it can build up, causing damage and clogging the process by which our body cleanses itself.
While, the Journal of the American College of Toxicology did find that some studies indicate residual levels of SLS can build up in the liver, heart and brain via the skin(1), the Cosmetics Datatbase references the Environmental Canada Domestic Substance List in categorizing SLS as "not known to bioaccumulate in wildlife or humans." Confused?
As for the cancer risk, I could find no definitive in vivo test (where the test is actually done on a living human being) showing a cancer link with SLS. Cosmetics Database quotes the Bulletin of Environmental Contamination and Toxicology from 1982 as showing "one or more in vitro tests on mammalian cells show positive mutation results." This means that 27 years ago, scientists were able to prove mutagenic cell growth in a lab dish. Most in the cosmetics industry (both traditional and watchdog groups) dismiss the cancer link. The situation gets gray with SLES. SLES is formed from SLS in a chemical process involving the presence of 1,4 dioxane. 1,4 dioxane is considered a carcinogen by the EPA, and the FDA strongly encourages -- but does not require -- manufacturers to remove it.
The biggest deal with SLS, SLES, and all of their "relations" (visit EWG's Cosmetics Database for a comprehensive list of related components) is their tendency to irritate skin. SLS/SLES are nothing more than detergents, which means they lather up great, but they remove a lot of naturally occurring skin oils: your skin and hair get dried out, and some people experience irritation or canker sores.
What's the take-home message?
Check the labels of EVERYTHING. You'll be surprised how many places and in what products SLS/SLES show up. Even products labeled "Organic" or "Natural" can contain SLS/SLES.
As stated before the purpose of these blog entries is not to label "good" or "bad"; everything must be taken in context. Can SLS cause contact dermatitis? Yes, in some people. But there are foaming agents that are far worse for you. Is a shampoo that is SLS-free "good" for you? Only if you look through the ingredient list and find it free of all the other harmful chemicals out there. Are products that contain SLS carcinogenic? I personally think the jury is out, but your position might be, "Why take chances?"
On a personal note, the toothpaste I use contains SLS. I like this toothpaste and will continue using it. On the other hand, my shampoo contains it also, and I have noticed much drier scalp and hair since using this shampoo; I will try another brand.
The last word.
Lab-created chemicals are scary; they came into our everyday life promising better quality products and healthier living. Now they are everywhere, and most of us don't know what they are, why they're there or how safe they are. Once a chemical, like SLS, is targeted, products show up everywhere advertising that they're "SLS-free." You, as a consumer, aren't given all of the information, and choosing a toothpaste becomes more confusing than your tax forms.
Read the labels on everything. I can't stress that enough. If you don't know what a chemical component is, look it up. And use several sources, because some websites have their own agenda. My best advice is, when checking the ingredient listing, if you don't know what three of the ingredients are, put the product back on the shelf. There are many companies out there that carry shampoos, deodorants, and toothpastes with easy-to-understand ingredients.
For further information on Sodium Lauryl Sulfate and Sodium Laureth Sulfate, these are some good starting points:
Wikipedia
Treehugger "Common Eco-Myth: Sodium Lauryl Sulfate (SLS) Causes Cancer" (read through the comments to see how passionate some people get about this topic)
Jason Cosmetics "Sodium Lauryl Sulfate in Shampoos, The Real Story"
Environmental Working Group's Skin Deep Cosmetic Safety Database
Wishing you much health!
(1) "Final report on the safety assessment of sodium lauryl sulfate." Journal of the American College of Toxicology; 1983; 2(7). Also quoted at http://www.jasoncosmetics.com/sodium_lauryl_sulfate.html
posted by Liisa at
12:01 PM
2 Comments:
SLS hasn't been shown to be a carcinogen. Though it is a skin irritant(sensitiser) that breaks down the proteins in the skin that make it easier for the other cancer causing ingredients in your products absorb through the skin. This is what I am finding in my research. It can also cause dermatitis.
I agree, MaryAnn, that's why I say "I could find no definitive in vivo test showing a cancer link with SLS." I agree also that it is linked with contact dermatitis, although this is on a case-by-case basis. Since SLS and SLES are detergents, they remove skin sebum, which can irritate people with sensitive or dry skin.
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