What Is SLS?

Sodium lauryl sulfate (SLS) is a surfactant, which basically means it has an effect on the surfaces it touches. It’s used in a variety of products such as food thickeners, toothpaste, and floor cleaners. 

Uses for Sodium Lauryl Sulfate

All the soaps and cleaning products that you use are a mix of water and oil. But they don’t mix together on their own. 

Instead, surfactants bring them together. Soap's cleaning power comes from the bonded oil and water molecules rubbing against dirt and grease. 

That is why so many products have surfactants in them. They blend the ingredients that make cleaning happen.

Sodium lauryl sulfate is very easy and inexpensive to make, and it works well in many situations. You'll see it listed as an ingredient in common products found in the home and in the workplace. 

Personal Products. These include things like:  

  • Body wash
  • Hand soap
  • Facial cleaner
  • Bubble bath
  • Toothpaste
  • Shampoo

SLS is also a foaming agent. Many of these products use SLS to give a foaming action during the cleaning process. If you have a foaming face wash or are working up a good lather with your shampoo, you're probably using something with SLS.

Cleaning Products. Sodium lauryl sulfate’s ability to break down oil and grease lends itself well to industrial products. You can find it in household cleaning products as well as engine cleaners and industrial-strength soaps. 

Food. You may see SLS used in certain foods you eat, within limits approved by the FDA. As a food additive, SLS can make marshmallows fluffier and dried egg products lighter. It helps mix citrus and other acidic liquids with water to make fruit drinks. 

However, SLS is not allowed in food globally. In fact, it is banned from being used as a food additive in the European Union. 

SLS and Safety

Your skin works hard to keep damaging things from getting through its top layer. Surfactants generally can be harmful because they can sometimes penetrate that layer. 

But experts say that SLS that gets through the skin is quickly broken down and turned into waste matter.

Continued

Research has found that SLS can irritate the skin and that warm water makes the irritation worse. This tends to go away when you stop using the product with SLS. 

But when you use a facial cleanser, toothpaste, or shampoo, you usually wash it off right away. So even though sodium lauryl sulfate is a known skin irritant, it can be used on the skin and in the mouth as long as you don't keep it on for too long.

Product labels must state that SLS is in the mix. Only so much of it is allowed to be in any given product, though the amount may vary by country. 

In the U.S., if a product is meant to stay on the body for a longer time, it can have only 1% SLS. In most cases that people report extreme skin irritation from SLS, they have left it on for too long or used it in a concentration too high for them. 

Is sodium lauryl sulfate carcinogenic? Products containing SLS go through frequent, thorough testing. No major national or international cancer organization or research center has found sodium lauryl sulfate to be linked with cancer.

Does sodium lauryl sulfate cause hair loss? Researchers have also concluded that SLS does not cause hair loss. 

Does sodium lauryl sulfate cause cataracts? Researchers point out that the lens of the eye, where cataracts form, is protected by other parts of the eye. SLS can't touch the lens, so it most likely doesn't cause cataracts. Still, you should try to keep products with SLS out of your eyes.  

So is it safe for everyone? If you have very sensitive skin and are prone to rashes, you might want to stay away from sodium lauryl sulfate. If you have a skin condition such as rosacea or psoriasis, you may want to do without SLS in your body wash.

Additionally, you should also note that SLS and its negative effects greatly depend on the formulation that it is in. One product that has SLS might be easier on your skin than another product that also has SLS in it. 

Talk with your doctor or pharmacist if you think a product is irritating your skin. They can probably offer other options.

WebMD Medical Reference

Sources

SOURCES:

American Chemical Society: “Sodium laureth sulfate.”

Environmental Health Insights: "Human and Environmental Toxicity of Sodium Lauryl Sulfate (SLS): Evidence for Safe Use in Household Cleaning Products."   

European Medicines Agency: “Background review for sodium laurilsulfate used as an excipient.”‌

The University of Queensland: "What is sodium lauryl sulfate and is it safe to use?”

U.S. Food & Drug Administration: "CFR-Code of Federal Regulations Title 21."

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