The skin is comprised of many layers and must be carefully maintained by many regulatory mechanisms of the body. pH balance on skin is important as it is known to affect the skin’s barrier. Each beauty product used can improve or impair the skin barrier after repeated use. SLS stands for Sodium Lauryl Sulfate and is an effective surfactant which helps to remove residue. SLES is a similar compound called Sodium Laureth Sulfate which supposedly is a slightly less irritant. These compounds can be claimed as natural as it is derived from coconut oil, but there are several health risks that are associated with SLS. It is also used in various toothpastes, shampoos and cosmetic products as it has a thickening effect and ability to create a thick lather which is what some people find to be what ensures they’re doing a good job when in the shower. So why is it so bad for you?
Due to the irritative nature of sodium lauryl sulfate, it is advised that patch tests are put into effect. As an ingredient in toothpastes, SLS can also cause adverse side effects to the soft tissues within the mouth. According to a study by Bente Herlofson, Pal Brodin and Harald Aars, the range of SLS found in toothpastes can range from 0.5-2.0% and found that it increased blood flow around the gums with prolonged exposure which demonstrates its ability to enter the bloodstream. Got canker sores? Your toothpaste may be to blame. SLS is also associated with increased aphthous ulcers (canker sores) due to the denaturing effect and irritation of the oral mucosa. Gross. But although it may be irritating to some gums, the SLS in your toothpaste may also be beneficial by removing toxins absorbed from the plaque on your teeth.
Now this doesn’t sound so bad does it?
That may be true, but the problem with SLES/SLS is that the manufacturing process (called ethoxylation) results in SLES/SLS being contaminated with 1,4 dioxane, which is a carcinogenic by-product. 1,4 dioxane contaminates up to 46% of personal care products tested! Yuck! SLS also exerts its damage by stripping your skin of protective oils and moisture. The decreased hydration of skin is associated with impaired barrier function and increases the skin’s susceptibility to irritation.
To avoid 1,4 dioxane, the Organic Consumers Association (OCA) recommends avoiding products with indications of ethoxylation. To do this, look for the following suffixes in the ingredient list: “myreth,” “oleth,” “laureth,” “ceteareth,” or any other “eth,” “PEG,” “polyethylene,” “polyethylene glycol,” “polyoxyethylene,” or “oxynol.” Geez. What a mouthful, right?
Bottom Line? We don’t know too much about long-term exposure to SLS and its associated contaminants, but the best advice is to avoid them and avoid the risk altogether—since there are definitely safer alternatives out there.
Let me know what you think! Do you avoid SLS/SLES?
Lee, C. H., Maibach, H. I. (1995). The sodium lauryl sulfate model: an overview. Contact Dermatitis. 33, 1-7.
OCA (Organic Consumer Association). 2008. Consumer alert. Cancer-causing 1,4-dioxane found in personal care products misleadingly branded as natural and organic. Available: http://www.organicconsumers.org/bodycare/DioxaneRelease08.cfm.
EWG (Environmental Working Group). 2008. EWG Research Shows 22 Percent of All Cosmetics May Be Contaminated With Cancer-Causing Impurity. Available: http://www.ewg.org/node/21286.
Barkvoll, P. (1989). Should toothpastes foam? Sodium lauryl sulfate–a toothpaste detergent in focus. Nor Tannlaegeforen Tid, 99(3), 82-84.