There is no cancer risk from SLS (Sodium Lauryl Sulfate)

I now duck as the tomatoes start to fly.

You might call it a brilliant stroke of marketing genius. You might call it a widespread hoax. Sodium Lauryl Sulfate (SLS) is surrounded by some of the greatest confusion and mis-information in the industry. In short, SLS has a very bad reputation, and it is such a phenomenon that I think somebody should write a book on it. It has become more vilified than any other chemical in bodycare, while those that are much more problematic pass freely beneath the radar.

The most damaging claim against SLS is that it is carcinogenic, because it supposedly creates nitrosamines. However, since it contains neither a nitrogen nor an amino group, this is chemically impossible.

SLS is in our Sal Suds all purpose cleaner, and here’s what we say about it on the bottle:Sodium Lauryl Sulfate (SLS) is a surfactant that cuts grease and dirt, generates copious suds, and biodegrades quickly and completely. SLS is made by combining a sulfate group with lauryl alcohol from coconut oil, then attaching sodium. If improperly formulated, SLS can irritate skin, but our superb formula uses coco-betaine and lauryl glucoside to counter this.

Sal Suds is a mild, synthetic detergent, not a bodycare product. SLS does not, and never has, appeared in any of our soaps since the saponified vegetable oils in our castile soaps are much, much better for our skin, and can be certified organic. SLS is synthesized (read “man made” or “processed”) even though it does have a coconut base.

Dr. Bronner's Sal Suds cleaner

I think this article has a good overview of the rumors: This page is written by Ed Friedlander, a pathologist from the Kansas City University of Medicine and Biosciences. I haven’t met him. He may or may not know about Dr. Bronner’s. (Take note that David Steinman, to whom Ed refers at the end, has done a great deal of excellent research and analysis on the topic of 1,4 Dioxane in bodycare products, among things.)

I don’t know who or what started all the fuss. There’s some idea that the initial claims were written by a company making a rival chemical to SLS. Or perhaps it’s that SLS is such an effective cleaner even in really greasy jobs, there must be something malignant about it. Or it could have been an understandable mix-up with sodium laureth sulfate, which is indeed linked to carcinogens (see my next blog on the “-eth’s”). Nevertheless, the rumor about its carcinogenic power spread like wildfire over the web, assisted by the general public’s accurate and growing suspicions that bodycare companies were lying to them.

Unfortunately, SLS became the scapegoat for these suspicions, and real culprits slipped by. Huge corporate bodycare companies took full advantage to extract as many dollars as they could out of this paranoia. Soon, the onslaught of “SLS-Free” products hit the shelves in Whole Foods, Wild Oats, and other natural stores. The thing is, many of the other ingredients in these products were petroleum based, and much more harmful to the body and the environment than SLS. However, with this artificial “SLS-Free” distinction, these green-washed products soon became best-sellers even within the super-green community.

That is why the whole SLS panic really bothers me. Aside from the fact that most of it is untrue, it is being exploited by the most unscrupulous companies. Frequently, chemical magazines contain articles about how to replace SLS in bodycare products with petroleum based water softeners. Trust me when I tell you that petroleum based water softeners are worse.

When SLS is not formulated properly, it can be an irritant to the skin. And since I can’t vouch for how it is formulated by each company that uses it, I avoid it across the board in all body care products. It should never show up in certified organic products. However, it appears in almost every conventional toothpaste and shampoo, and even in many that are sold by “natural” brands. Since there are tentative links to causing canker sores in the mouth, as well as acknowledged skin irritation when not balanced properly, I think it’s best to steer clear of it for bodycare. I can do without the bubbles.

So, this blog has gone on long enough. I haven’t addressed the whole SLES and 1,4 Dioxane issue (which is linked to Sodium Laureth Sulfate, among other things, but not Sodium Lauryl Sulfate). I will pick that topic up next time.

Note: My brother Mike Bronner had a hand in writing part of this.

77 thoughts on “There is no cancer risk from SLS (Sodium Lauryl Sulfate)

  1. Hi Lisa, when you say “half cup”, may I know what is the actual amount? Thanks!


  3. Hi Lisa,

    Why si Sal’s Suds so hard to find? has a few bottles fut want 46 – 98/ for 16 and 32 oz sizes. Even Dr. Bronners’s site is out of stock. When will it be available?


  4. Time for true confessions, folks. It is February 9, 2017, and I have missed several months of comments for the simple reasons that things went a little crazy around here. I very much apologize. I am tackling them now for the sake of those faithful and new readers who might actually read them all. I am going to start with the most recent. Bear with me.

    • Hi Diana – I apologize for not seeing your comment from March earlier. I appreciate your in depth look into this issue. The Dr. Mercola article continues to lump together SLS and SLES, which though related have significant differences. (From the article – “The real problem with SLES/SLS is that the manufacturing process (ethoxylation) results in SLES/SLS being contaminated with 1,4 dioxane, a carcinogenic by-product”) SLES is the only one of the two that undergoes ethoxylation, which is the process that produces the carcinogenic byproduct 1,4 Dioxane. SLS does not contain a nitrosamine group and therefore cannot have the carcinogenic concern. Another error in the article is the reference to the rating given to SLS by the Skin Deep database. SLS earns a 1-2 hazard score, almost the lowest possible hazard. (See SLES is the one that gets the moderate hazard score (

      I know this is enough chemistry to make the head spin, but I hope this helps clear up some of your concerns.

  5. Lisa, I’m so happy that I found your website! I’ve used Dr. Bronner’s products for decades. To be honest, I trust these products so much that I don’t even look at the ingredients. Thank you for clearing up the discrepancy between sodium LAUREL sulfate (the good ingredient) and sodium LAURETH sulfate (the bad ingredient). I would never realized there was a difference. I color my hair, and I heard that sodium laurel sulfate would be a no-no on color-treated hair; thus, I’ve bought SLS-free shampoos and conditioners. Maybe I can go back to other products that I really like, if it’s okay that they’re made with sodium laurel sulfate.

    • Hi Jan – I apologize that I didn’t see you comment earlier. The only issue with SLS in personal care products is that it can be drying.

  6. Your Sal Suds comes into contact with our hands so, while you do not use it in your body products, it still gets rubbed into the body during normal use. I suppose you want us to wear gloves, but I prefer a more natural product that does not require body shields during usage. Why not just change to a more benign suds-producing ingredient, as other natural products have already done?

    • Hi Janice – Thank you for sharing your concern. We don’t necessarily recommend using gloves with the Sal Suds unless it is drying out your hands. Sodium Lauryl Sulfate really is one of the most benign synthetic ingredients available. The Cosmetics Safety Database gives it a 1-2 in their hazard rankings (, which is almost the lowest (i.e. least hazardous) ranking they have. SLS has been super targeted by false marketing. It’s only drawback is that it can be drying to skin, which is why it shouldn’t be in personal care products. There is no other risk of harm to our bodies from it. All that being said, it is a synthetic ingredient, which is why any product that contains it is actually a detergent, as is our Sal Suds. If you’re looking for a natural product, the Dr. Bronner’s Castile Soap is made entirely from pure plant oils.

  7. Am I too late to this dogfight?

    I could conduct research on endless ingredients in all the products I consume. Sorry, don’t have the time. Yes, I am interested but at a certain point, I either trust or distrust the product’s maker. And if it has Dr. Bronner’s stamp of approval (after copious research, I am sure), I will accept it’s safe.

    • Thank you, Terrance. We value our customers’ trust very highly.

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