Sodium lauryl sulfate (also known as SLS), sodium laurel sulfate and its relative sodium laureth sulfate (SLES) are foaming agents commonly used in personal care products such as shampoos, cleansers, body washes and toothpaste to produce that lather that many of us equate with being and feeling ‘clean’. You have probably read many reports on the internet and by other well intentioned individuals and companies that claim sodium lauryl sulfate is a carcinogen and should be avoided. Is it really dangerous? Is it safe? Does the truth lie somewhere in between?
What is SLS?
Sodium lauryl sulfate and sodium laureth sulfate are classified as surfactants. This means that they act like detergents and emulsifiers and are added to cosmetics products for their ability to remove dirt and oil. They are relatively inexpensive and work well – two reasons why they are used so widely. While many claim that both SLS and SLES are carcinogenic, the American Cancer Society definitively maintains that there is no link between SLS and cancer.
Where Did The Claim Originate?
SLS is formed by combining sulfate and lauric acid, two compounds readily found in nature. Because SLS is such an effective cleanser, it can be highly irritating to the skin and eyes. In fact, it is often used in clinical testing to irritate skin in humans and animals so that researchers can then gauge the effectiveness of healing agents on the irritated skin.
In the 1970s some shampoos were found to be contaminated with small amounts of nitrosamines, which are carcinogenic. It was determined that ethanolamine lauryl sulfates (and not sodium lauryl sulfate) was the responsible agent. Manufacturers addressed this by discontinuing the use of this ingredient. However, both SLS and SLES may also be contaminated with 1,4 dioxane, which is a probable carcinogen. The FDA encourages manufacturers to remove 1,4 dioxane from SLS but it isn’t required by Federal law. Because it isn’t legislated, it’s difficult to know whether the SLS in your personal care product does or doesn’t contain 1,4 dioxane. The FDA maintains that trace amounts of 1,4 dioxane found in personal care products are not harmful.
What Does This Mean For You?
Although the research seems to suggest that sodium lauryl sulfate and sodium laureth sulfate are not carcinogens, they are irritants. And, there is the risk for contamination with probable carcinogens. However, since most products containing them are rinsed off quickly, they may not be cause for concern. Still, if you have sensitive skin or are looking for a product for children, then you may want to avoid products containing SLS or SLES. And certainly, if you want to avoid the risk of contact with a probable carcinogen, then seek out products that claim to be 1,4 dioxane free or SLS/SLES free.
Here are some products to consider: