Common Eco-Myth: Sodium Lauryl Sulfate (SLS) Causes Cancer
by Jeremy Elton Jacquot, Los Angeles on 07. 2.07
Companies have often gone to great lengths to exploit widely held consumer beliefs, however misguided, and translate them into higher profit margins. In recent years, we have seen efforts by firms operating in a variety of industries, ranging from the food industry (see latest non-fat/vitamin enriched/sugar-free/etc fad) to the cookware industry (see a recent post on the Teflon pan/PFOA exposure myth here), to capitalize on some of these misperceptions by airing and marketing them.
One such misperception that has managed to persist in the public domain over the last few years is the perceived carcinogenic risk posed by sodium lauryl sulfate, a chemical commonly found in beauty care products. Despite strong evidence to the contrary, including an article published by the American Cancer Society definitively positing no link between SLS and cancer, this urban legend remains ingrained in many consumers' minds. We decided to go on our own little fact-finding expedition to get to the bottom of this widely-held myth.
Part of the confusion likely arises from the fact that sodium lauryl sulfate is in fact frequently implicated in cancer experiments. However, it is always used to solubilize chemicals prior to being injected into test animals and never as the active ingredient. No evidence in the literature has ever been found directly linking SLS to cancer.
SLS is a coarse powder that is often used as a foaming agent or detergent in soaps. It is created by joining sulfate and lauric acid, two compounds widely found in nature. According to Dr. Ed Friedlander, SLS' properties as a skin and eye irritant make it an ideal model for skin contact dermatitis. Indeed, a recent search of the literature using the National Center for Biotechnology Information (NCBI) search engine PubMed found most SLS citations in articles published in dermatology journals like Contact Dermatitis.
One dubious claim often made by the dozens of anti-SLS websites is that sodium lauryl sulfate is carcinogenic because it produces nitrosamines when it reacts with formaldehyde. Since neither compound contains a nitrogen atom, however, that is chemically impossible.
Despite the fact that there was and still is no hard evidence to back up the link between SLS and cancer, many unscrupulous companies took advantage of the suspicions and allegations raised by such websites to market as many "SLS-free" products as they could, often selling them to major organic/natural stores like Whole Foods and Wild Oats, thus helping to further legitimize this myth. Although many of these body care products contained far more harmful chemicals such as parabens and ethanolamines (which do contain nitrosamines), the sole scapegoating of SLS allowed these companies to safely continue using them without arousing much public scrutiny.
David Bronner, President of Dr. Bronner's Magic Soaps, has long felt that SLS has been unfairly scapegoated in the beauty care industry. "We do feel that SLS has been incorrectly scapegoated, as a lightning rod for legitimate consumer concerns about cosmetic ingredient safety ... the issue with SLS primarily has to do with it being irritating to skin, which can be addressed by buffering with ingredients like Coco Glucoside," he said, stating that his company doesn't use it in any of its personal care products (though it does use it in one of its cleaning products).
He argues that those chemicals that do pose potential health effects have largely been ignored.
"Ethoxylated ingredients in personal care, including SLES, Sodium Myreth Sulfate, PEG ingredients, etc., are a problem due to 1,4 dioxane contamination. The dioxane can be vacuum stripped to less than 10 ppm levels, but especially with personal care products, the cumulative effect of constant low-level exposure from different dioxane containing products is unknown ... Other ingredients of concern in cosmetics are formaldehyde donor preservatives, parabens, nitrosamine containing ingredients like ethanolamines (any ingredients with MEA, DEA or TEA)."
The easiest way to get rid of all these potential health risks would simply be to formulate away from ingredients that involve petrochemicals, a point he recently emphasized in a video criticizing companies for incorrectly claiming to be "natural" brands.
As always, we recommend you do your own research if you're still not fully convinced and ask the manufacturers of the beauty care products you use for their policies on SLS (most should have it on their websites). Also feel free to check out our "how to" guide on women's personal care for more tips and don't be shy about weighing in with your own opinion.
See also: ::Movie Review: Dr. Bronner's Magic Soapbox, ::Common Eco-Myth: Wind Turbines Kill Birds, ::TreeHuggers Show Some Skin for Bert, Juice, NOW, & Avalon, ::The Greater Good: Burt's Bees Campaign for Truly Natural Personal Care, ::domino & TreeHugger's Green List: Beauty
You'll notice it says the risk is low, not nil. The question the Precautionary Principle asks is, why should we subject ourselves to unnecessary risks? Why not use safer alternatives?
You don't have to be a fearmonger to say, let's look at why so many of our products are made with toxic chemicals. Does it HAVE to be this way?
This is a weird post that makes me wonder if the author works for a chemical company.
Your post on the PFOA/teflon "cooking myth" is ridiculous. Yes, exposure from cooking may be minimal. But, look carefully at your teflon pans, and tell me how many silver scratches you see in them. Where'd your coating go?
Now do some research into the biggest civil fine ever levied by the EPA:
http://www.organicconsumers.org/foodsafety/dupont121605.cfm
http://pubs.acs.org/subscribe/journals/esthag-w/2006/jan/science/rr_arcticPFOA.html
http://www.albionmonitor.com/0512a/teflonsettlement.html
http://www.msnbc.msn.com/id/10465449/
Treehugger, you need to check yourselves before you wreck yourselves. Or are you getting paid by DuPont?
SLS has been shown to lead to canker sores. The above mentioned harshness of the chemical has been proven to cause microscopic damage to the oral mucosa that leads to the formation of these mouth ulcers.
Here's a list of the SLS free toothpastes now available:
http://www.dentist.net/sls-free-toothpaste.asp
So I need to ask...
If you don't get your reliable information here... then where do you get your reliable information about chemical risks?
Some folks on this board may want to re-think what you're scared of. If this is high on your list, you may have mis-placed your priorities.
The article makes a few very good points. SLS while being a sensitizer; is not nearly as much of an irritant as something like Black Pepper. We should ban that?
Parabens, which are more harmful than SLS will ever be; are in MOST beauty care products becase they are EXCELLENT at reducing microbial activity in formulations (microbes that are MUCH more harmful than the parabens themselves.)
To live a longer and healthier life, quit worrying so much about an ingredient that a qualified scientist has data to show is innocuous. Get out and get some fresh air - sitting in front of a computer all day will kill you!
Willy
Beauty Care Formulation Chemist
This article makes some absurd claims to be sure (especially the teflon pan et al. examples). You guys aren't doing your research, nor are you scientists, so don't post so lightly.
even dandruff shampoos gave me dandruff. I now use Dr. Bronner's liquid castile almond oil soap for shampoo...no more dandruff....was SLS the culprit?
auntcarol
I don't understand why Alba is one of your favorite lines. Today I bought a shampoo and getting home I saw that it contains parabens (methylparaban and propylparaben to be exact)
Thank you so much though for your website, it's awesome!
MX
How about don't use SLS because it dries out your hair? I mean you say yourself it is a coarse powder they use to make foam, it has nothing good for hair in it, they just want to make your shampoo foamy because people equate lots of bubles with cleanliness. It is totally unnecessary. I use Burt's Bees natural shampoo and think it is awesome.
the issue I have with SLS, SLES, and parabens too is not fear of cancer, but how those ingredients burn and irritate my skin (and in the case of estrogenic toxins like parabens, how the use of products that contain such ingredients can make me experience worse symptoms from endometriosis, an estrogen-related disorder). Seems this article is only knocking down a straw man rather than addressing the real issues at hand.
I trust my body to tell me when something is toxic to my system, and products containing SLS are definitely a problem for me, personally. If your head burns and itches after using a particular shampoo, the intelligent thing to do would be to stop using such products. There are lots of other options you can use to keep your hair clean, they just might not suds up as well but they can and will do a pretty good job.
I stopped using SLS and any other sulfites in my hair and skin products due to its drying effect. I have somewhat delicate curly hair, and in the year and a hlaf since I cut out the sulfites my hair has gotten dramatically healthier and some mild body acne that I had has cleared up.
I've never believed the SLS/Cancer link. It doesn't make sense to me, but that doesn't mean it's all well and good for skin and hair products.
Confusing article: first it says that SDS (SLS) is not connected with cancer. This is the first time I have heard anything about anyone believing there ever was such a connection. Then it goes on to say that SDS is a skin irritant. I thought this was much more debated although what do the articles in Contact Dermatitis say?
EWG gives it score 2 (zero is good) with a 72% data gap...
http://www.cosmeticsdatabase.com/ingredient.php?ingred06=706110&refurl=%2Fwordsearch.php%3Fquery%3Dsodium+dodecyl+sulfate%26
what is it with SDS that makes it irritating, and why would addition of coco glucoside decrease (or mask) that effect?
anyway, if you want to know more about beauty products and the chemicals in them by all means have a look at EWGs site: http://www.cosmeticsdatabase.com/
I've been writing about the dangers of SLS for about 40 years!! (Since 1968).
For a definitive answer go to the Environmental Working Group website: www.ewg.org
Look at the toxins list at www.butterflybush.org. and in Judy Vance's book BEAUTY TO DIE FOR... and in Debra Lynn Dadd's book HOME SAFE HOME.
The MSDS sheet for Sodium Laureth (or Laurel) Sulfate says wear rubber suit, respirator and rubber gloves when handling! It's used in laboratory experiements as a major skin irritant.
My hair QUIT falling out in gobs when I quit using products that contained SLS & propylene glycol over 30 years ago!! The hair follicles plug themselves up with a waxy plug to keep SLS OUT...! So your hair falls OUT too!
SLS is NOT safe to use... or so MANY companies wouldn't be pulling toxic ingredients out of products these days!
I agree with the above posters concerning the skin drying and irritating properties of SLS. I never started avoided SLS because it was carcenogenic but because every time it touches my skin I end up with irritated, dry and sometimes burned skin.
It seems to me that there are plenty of reasons other than cancer-risk to make SLS-free products. To call companies that cater to people with sensitive skin "unscrupulous" is a little too much for me.
As soon as I saw this entry I went to the Environmental Working Group website, which I depend on heavily for beauty product safety information. It confirmed that neither Sodium Lauryl Sulfate nor Sodium Lauryth Sulfate (both referred to as SLS) are very dangerous at all (of the two, the more dangerous received a danger rating of 2 out of 10 with 10 being the most concerning). However, another site linked in this article (Campaign for Safe Cosmetics, safecosmetics.org) points out that the chemical 1,4 Dioxane, banned for use because of its mutagenic properties, shows up in personal care products because it is the byproduct of some chemical ingredient manufacturing processes, including the process by which sodium lauryl sulfate becomes sodium laureth sulfate. I'm still going to avoid products with SLS in them, knowing that they could have Dioxane in them.
An important point to consider in regards to the safety of personal care products is the cumulation of these chemicals in our systems with exposure to multiple products with these ingredients day after day. Often the safety of an ingredient in a single personal care product is evaluated in isolation and may in fact be relatively safe if a person used only one product with the concerning ingredient on an infrequent basis, which is not a realistic assumption.
NOTE: Do not confuse Dioxane with Dioxin. Dioxin is extremely nasty. Dioxane is much less dangerous, though still not good. Dioxane is a common industrial & personal care manufacturing process product pollutant.
To whom it may concern,
Please use a different color besides pink for your font lettering in your articles and comments because it is hard to read against a gray background. Thank you