Sodium Laureth Sulfate - sodium salt or sulfated ethoxylated lauryl alcohol - used as a water softener, cleansing wetting ingredient, and a surfactant (allows product to spread more easily). There has been a lot of incorrect press regarding this ingredient. This information stems from an article by Neways Web site and misquotes and falsifies Dr. Keith Green's information. The American Cancer Society has stated that SLS does not cause cancer. If you get this product in your eyes it will sting and can be an irritant to lungs and skin - other than that no reproductive toxicity or cancer has been connected. The Environmental Working Group - Skin Deep, they are a major source of great information regarding cosmetic ingredients, I check all ingredients that are used for Skin Essentials products for their safety with the Enivronmental Working Group - Skin Deep before using anything new in our products. For more information see www.cosmeticsdatabase.com/ingredient.php