Ingredients We Avoid : Sodium Lauryl Sulfate (SLS)

What is SLS?


Sodium lauryl sulfate or SLS is a common ingredient in many commercial beauty and industrial cleaning products - ranging from toothpaste to floor cleaner. It is widely used as a foaming agent and is what makes these products ‘froth’ and ‘lather’. SLS is also used as an emulsifier, binding the ingredients and stopping them from separating.  

It's formed from petroleum oil via the OXO process, or from coconut or palm oil via the Ziegler process where fatty acids are turned into fatty alcohols.

What are its uses?


SLS is a low cost, tasteless, anionic detergent and surfactant. This means that it effectively separates molecules for better widespread contact between the product - in this case between the toothpaste and mouth, creating the lather effect we have all become accustomed to. These properties enable the product to absorb and disperse stains and build-ups, aiding in cleaning your teeth. SLS is also an effective emulsifier keeping ingredients in toothpaste together, as mentioned above.

Why do we avoid SLS?


It has become a popular ingredient in many oral care and beauty products but has been linked with some concerning side effects.

The Journal of American Toxicology states that SLS has a “degenerative effect on the cell membranes because of its protein denaturing properties” and can penetrate skin even at low levels of concentration.

SLS is not food grade, and the mouth is the most absorbent part of the body. Regular and cumulative exposure will inevitably result in ingestion of these chemicals. As our bodies are unable to break them down, negative side effects can occur.

Studies involving the long-term cumulative effects of continued SLS exposure are lacking – which is worrying and many specialists have advised that SLS is used with caution.  

The effects on your body and the environment


The largest known negative side effect of SLS is increased mouth inflammation and irritation of the mouth and lips which can cause swelling and sores. It has a reputation as an irritant, so much so that it is actually used as a marker in scientific studies when testing the safety of other ingredients to help reduce irritation.

Like all detergent surfactants, SLS removes oils, having a drying effect which can contribute to dry mouth. Dry mouth is literally a dryness of the mouth that can lead to an overgrowth of bacteria causing gum disease, swollen gums and canker sores.

The effect of SLS on existing aphthous ulcers or canker sores is a painful one. It also has been linked to negative incidents of oral irritation for subjects that are prone to mouth ulcers. In 2012, the Journal of Oral Diseases from the US National Library of Medicine identified that duration and pain score of ulcers significantly decreased with SLS free participants in a controlled study with 90 tested subjects.

SLS is commonly used alongside fluoride, another potentially harmful ingredient we choose to avoid (read more), however, it has been shown to decrease the effectiveness of fluoride deposition on strengthening tooth enamel – so you’re ingesting two harmful synthetic chemicals with little positive results.

SLS can also be toxic to our environment, if it gets into the water systems it can bioaccumulate and is toxic to marine life.

We feel that SLS is an unnecessary health risk to expose ourselves to and want to be able to offer natural and gentler alternatives that have the same effect but don’t irritate your mouth.

Milder alternatives in our oral care products


In our natural toothpaste, we have omitted a foaming agent, which is why some people find our toothpaste takes a bit of getting used to. It’s still just as effective but doesn’t lather in the way many people used to. As a binder, we opt for virgin coconut oil.

Our natural toothsoap does lather, and for this, we use sustainably sourced sodium palm kernelate - which foams in the mouth. In this product we use sodium chloride as a binder. 

How to avoid SLS


If you want to avoid SLS, it can be quite confusing as it has a few different names. So look out for any of these on the label – and if you’re not sure, ask the company. If they have nothing to hide, they will answer you honestly and informatively.

  • Lauryl Sodium Sulphate
  • Lauryl Sulphate Sodium Salt
  • Sodium Dodecyl Sulphate
  • Sodium n-dodecyl Sulphate





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