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ALS vs SLS

We get a lot of questions about sodium lauryl sulphate (SLS) and ammonium lauryl sulphate (ALS). Here we explain the difference, and would also like to reassure you that our safe, natural shampoos are all ALS-free and SLS-free.

By Alexandra Julian

2 Minute read

We've put together some information about ALS and SLS which will hopefully be useful for you.

We get a lot of questions about sodium lauryl sulphate (SLS) and ammonium lauryl sulphate (ALS). We would like to reassure you that our safe, natural shampoos are all ALS-free and SLS-free.

Key points:

  • SLS and ALS are quite different
  • ALS is a much larger molecule and considered much less irritating than SLS
  • Looking for an SLS or ALS-free shampoo? Try Green People shampoos
  • The best option for very sensitive scalps is Scent Free Shampoo

What makes SLS irritating?

Although sodium lauryl sulphate (SLS) and ammonium lauryl sulphate (ALS) have similar sounding names and are both classed as anionic surfactants, they have different molecular structures. SLS is a comparatively simple molecule and is therefore quite small in size.

This gives it the ability to penetrate the outer layers of the skin, particularly when used in conditions which encourage the skin's pores to open, such as when in a warm bath or shower.

When SLS penetrates the outer layers of the skin in this way, it comes into contact with more delicate cells that are in the process of being formed in the dermis.

It is here that the irritation associated with SLS manifests itself, resulting in reddening and erythema of the skin.

How is ALS different?

ALS, by contrast, is a slightly more complex molecule and is physically larger with a heavier molecular mass.

This means that it is more difficult for ALS molecules to penetrate the outer layers of the skin and so reach the delicate underlying layers of cells.

Due to this difference, ALS is regarded as being considerably less irritating than SLS – on a scale of 0 to 10, where the potential irritancy of water is 0 and that of SLS is 10, ALS scores around 4 – clearly far less irritating than SLS.

SLS and ALS-free shampoos

We do not use ALS or SLS in our hair care products. All of our organic shampoos use different surfactants which are kind to skin. Full ingredients lists are available on each product page.

See our full range of SLS-free and ALS-free shampoos.

If you wish to republish this content, please credit Green People as the original creator with a link to ALS vs SLS. Please do not use an affiliate link.

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