≡ Menu

Beware of intellectual dishonesty

If someone only tells you half the truth, is that as bad as telling a lie?

What science says about SLS

I recently received a comment titled “What science says about sodium lauryl sulfate.” This person (I’ll just call her “R”) quoted a study published in the journal of the American College of Toxicology which raised concerns about the use of Sodium Lauryl Sulfate (SLS) and its cousin Ammonium Lauryl Sulfate. (ALS) Here’s part of what she posted in her comment:

In its final report on the safety of sodium lauryl sulfate, the Journal of the American College of Toxicology notes that this ingredient has a “degenerative effect on the cell membranes because of its protein denaturing properties.” What’s more, the journal adds, “high levels of skin penetration may occur at even low use concentration.” Interestingly, sodium lauryl sulfate “is used around the world in clinical studies as a skin irritant,” notes the journal.

R did not provide a link to the study in question but I did find it here. Unfortunately I don’t have access to the entire study but the link does include a detailed abstract.

From what I can tell, “R” quoted the article accurately and everything she said is true. But she omitted one VERY important piece of information from the conclusion of the study. Allow me to share that with you now:

Both Sodium and Ammonium Lauryl Sulfate appear to be safe in formulations designed for discontinuous, brief use followed by thorough rinsing from the surface of the skin. In products intended for prolonged contact with skin, concentrations should not exceed 1%.

Now, I’m not a toxicologist but my interpretation of this statement is that it’s okay to use SLS and ALS in a shampoo or body wash where the use would be “ discontinuous, brief” and would be followed by “thorough rinsing.”

Misinformed or misguided?

So why did “R” neglect to mention this very important point? I can think of three possibilities:

1. She didn’t read the entire study and missed the conclusion.
This is certainly possible if she only read part of the study which was quoted out of context. Not everyone bothers to trace back the original source of such studies.

2. She believes the part of study which describes the potential dangers of SLS and NOT the part that says it’s okay to use SLS in the proper context.
Unless “R” is a toxicologist herself, I don’t see how she is qualified to pick and choose which parts of the study are accurate.

3. In an attempt to make her point, “R” only told us the part of the truth that served her purpose and deliberately omitted information that disagreed with her point.
If this is the case the “R” is being intellectually dishonest. I hope this isn’t so.

The Beauty Brains bottom line

My point is not to just rally support for SLS. I agree it’s one of the more harsh surfactants that formulators have to choose from. There are many ingredients which are more mild. But based on everything I’ve read in my 30 years in this industry, I agree with the study’s conclusion that SLS is not dangerous when used properly. (By the way, I’m open to changing my mind if new, legitimate, data comes to light indicating that SLS poses a health hazard from a rinse off product.) Rather, my point is that if you’re going to write something that you title ““What science says about SLS” you should make sure that you understand what the science really says. Otherwise you risk scaring other people with misinformation.

What do YOU think? Leave a comment and share your thoughts with the rest of the Beauty Brains community.

Comments on this entry are closed.

  • Eileen February 26, 2014, 9:48 am

    There is a big difference between decoding words and reading with comprehension (ask any teacher!) and many people fail to grasp the actual ideas both expressed and implied when they read a lengthy article. Consequently, they tend to skip over things and take away from their reading only those things which re-inforce already held beliefs. Perhaps R is one of those people. Or, perhaps R is just one of those alarmists who is governed by an irrational level of fear. Or, perhaps R is just trying to scare people into considering R’s preferred line of products. Or, . . . Well, you get the picture. Bottom line: R is either limited in literacy skills or R is being dishonest by manipulating the information.

  • Darren February 26, 2014, 9:58 am

    Alarmist bullshit again. Great article Beauty Brains. Love your books and articles.



  • Michelle Reece February 27, 2014, 1:01 am

    Exactly! The studies concluding SLS being an irritant in patch tests *only* shows that it should not be *left on* the skin in high concentrations, nothing more! I’ve been trying to inform my friends, family, and others online, and some of them would rather believe that SLS is a harsh, evil, synthetic chemical! So frustrating!

    Thanks for tackling this subject! 🙂

  • Mary February 27, 2014, 8:30 am

    I agree that this poster heavily skewed the facts.

    However, I find it really odd that a site that loves to tout how evidence based it is would boast about how they appeared on FOX News channel, by far the most dishonest news network, and one that is constantly skewing facts to serve its own agenda. Sound familiar?

    • Randy Schueller February 27, 2014, 8:45 am

      Mary: When we appear on TV (and other media) we’re trying our best to spread the word about the importance of critical thinking with respect to beauty products. It’s not easy and we’re not always successful at getting our message across because of the limitations of appearing on someone else’s show but if we can convince even just one more person to think skeptically about cosmetics then we’ve accomplished something that we’re proud of. So, yes, we’ll boast about appearing on the Fox News Channel or the Dr. Oz show even though we don’t necessarily agree with everything else those outlets promote.

      • Eileen February 27, 2014, 10:05 am

        Ignoring lies and ignorance does not make it go away. Confronting it does–or at the very least, makes people think about the things they believe. I applaud you for going on shows like Fox and Oz. Elucidating and defending a different point of view doesn’t make you guys hypocrites. Quite the opposite. It shows the program viewers that not everyone has drunk the cool aid and that there are sound scientific reasons why.

  • Kai-Lee February 27, 2014, 12:34 pm

    I agree with all your points and think that use of this product is perfectly safe for healthy people. Having said that, I have atopic dermatitis and find that prolonged use of this product causes rashes for me and so choose not to use it. When discussing the safety of a product I wish people would distinguish between safety for healthy people and safety for everyone because articles like these lead to me having to defend my personal choices about my personal product use to people who feel they have a right to tell me what works for me or not because the scientific evidence supports their opinion.

  • Meira February 27, 2014, 3:33 pm

    I’m glad to read this, ’cause I’ve wondered about SLSs for a while. I know from personal experience that my hair is happier with shampoos that don’t contain them — but that doesn’t mean they’re BAD, only that my hair doesn’t appreciate them.
    But! SLSs are also in most toothpastes, and many people are of the belief that one should not rinse after brushing — in which case they would have prolonged exposure.

    • Randy Schueller February 27, 2014, 5:06 pm

      @Meira: People don’t rinse after brushing their teeth? That seems strange. Especially considering that you shouldn’t swallow fluoride (assuming their using a fluoride toothpaste.)

  • Ali February 27, 2014, 8:47 pm

    For me, I always thought the reason to avoid SLS was because of the persisting damage it does to the water systems. I agree that it seems relatively harmless for the skin.

  • Kevin February 28, 2014, 9:23 pm

    Great information. Too bad some people use this as a forum to bash a news organization they don’t like… how sad.

  • Rachel March 1, 2014, 12:11 pm

    I work in a care home, most staff never rinse shampoo/soap properly and our clients often have flaky scaly scalps and red inflammed skin prone to fungal infection….just sayin…
    It makes me MAD!!!!
    Am going to print off the extract for the manager

  • latine Salope May 25, 2014, 8:42 am

    Follement passionnant, je pense que cet article intéresserait ma meuf