What the Heck is SLS?
Have you ever tried to read the ingredients on the back of a bottle of shampoo or on a tube of toothpaste? Chances are good that if you have, you gave up in frustration after trying to sort out what looks for all the world like someone shook a chemistry textbook and a bunch of the words fell out onto the package. With all the specialized ingredients in a tube of toothpaste, it might be tempting to just give up and assume you’ll never really know what’s in there. Or, it can be easy to see a highly chemical name and assume the worst. Sodium lauryl sulfate, more commonly abbreviated as SLS, is one of those chemicals that seems to have a fair amount of suspicion swirling around it. Since SLS is an ingredient in so many personal care products, it’s worth taking a look at what it is, why it’s included in products, how safe it is, and if there are alternatives should you choose to avoid SLS.
What, exactly, is SLS?
Sodium Lauryl Sulfate is a type of chemical compound called a surfactant. Surfactants are valuable tools in the fight against grime. Surfactants are able to absorb both water and oils, which helps clean messes away and lets the mess rinse away with water. This ability to bind water and oil is what makes it an emulsifying agent. Sodium lauryl sulfate is also a foaming agent. It helps soap build nice even suds.
Why is SLS used in personal care products?
The primary reason SLS is used in personal care products is simple—it works. It’s an effective surfactant, and it is rated as generally safe for use by the Environmental Working Group. Not all effective surfactants are safe to be used on human skin, so SLS is appealing to make personal care products work better (or at all) while being safe.
SLS also has attractive aesthetic characteristics—it makes the products match our expectations. We commonly think of nice even suds as a sign of more effective cleaner, even though it’s not actually necessary to have suds to clean. Because we are conditioned to think of suds as a sign of clean, we tend to look for suds in products that we want to clean away dirt, products like shampoo, soaps, and toothpaste. Even though non-foaming products may work as well, we like the products we’re used to, and the products we are used to foam.
Is it safe?
It’s reasonable to ask this question about anything that you put on or in your body. The International Journal of Toxicology looked at this issue extensively and concluded that it’s safe for human use at low concentrations in products that are applied and rinsed away, like toothpaste and shampoo.
That’s not to say there’s no reason to take care. At higher than recommended concentrations, it can be a skin irritant. There is some evidence that creams containing SLS that stay on the skin can cause dryness or other irritation. This is part of the reason it’s recommended for rinse away products rather than products that stay on the skin. There has been some considerable discussion about the safety of SLS, and there are numerous claims on the internet that it is dangerous. A 2015 study, however, found that although SLS does have irritant properties, with proper use at low concentrations SLS should be safe to use.
Regardless of the safe rating for the general population, some people are more susceptible to skin irritation. In sensitive individuals, SLS can cause negative reactions and can be a source of irritation. If you are sensitive, it doesn’t particularly matter that the ingredient is generally safe. You’ll need to avoid products containing SLS to prevent irritation.
Can you avoid SLS?
Absolutely. With an increased interest in sulfate-free personal care products, there has been a growth in the amount of sulfate-free products available for purchase. In particular, toothpaste with SLS has been known to cause irritation for sensitive individuals, even though the majority can use it without issue. But, there are tooth cleaning pastes and gels on the market now that are SLS-free for those that need to be cautious. When choosing one, look for a product that contains beneficial ingredients like xylitol and nano hydroxyapatite that can maintain and even improve enamel health. The bottom line is you don’t need to choose a sulfate product to choose a healthy and effective cleanser.