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.