Palm oil and sodium lauryl sulfate

Sodium lauryl sulfate (SLS), otherwise known as sodium dodecyl sulfate (SDS), is a chemical commonly found in soaps, shampoos, moisturisers and other cosmetics and has gained a vague reputation as one of the ‘nasties’ shoppers should avoid. Many products marketing themselves as green, natural or eco make a point of being SLS-free.

SLS is known to chemists as an amphiphile – a Greek term that refers to its ‘love’ of both oil and water and gives a clue to its use in cleaning products. Oil and water don’t normally mix, so trying to wash oily skin or clothes with just water is fairly hopeless. But SLS – and other similar chemicals such as soap and detergents – acts as a bond between the two, allowing water to strip away greasy substances and dirt.

This ability to strip away oil partly explains why SLS is becoming unpopular as a beauty product ingredient. Skin naturally produces its own protective oils, so overexposure to a product that’s effective at stripping away oil can result in dryness, irritation and conditions such as eczema or dermatitis.

The palm oil problem

Of more concern for shoppers is the fact that SLS is often made from palm oil, a product that is linked to serious deforestation in areas where endangered orang-utans and tigers live. Other oils can be used as a starting product, but palm oil’s low costs make it attractive to cosmetics companies, meaning you may unwittingly be contributing to environmental damage when you shop.

A good way to avoid this trap is to check the ingredients list on products you use and choose those that are either SLS- (or SDS-) free or contain alternative ingredients such as sodium coco sulfate. Sodium coco sulfate is effectively the same ingredient as SLS and has similar irritation issues, but is derived from coconuts, which are a more environmentally friendly crop.

Are there health issues?

Dr Julie Smith, of Auckland’s Julie Smith Dermatology clinic, gives a resounding “no” when asked if SLS is dangerous. Various myths have circulated the internet linking SLS to cancer but these are unfounded, Dr Smith says, and the chemical’s irritating effect is no concern in products such as shampoo or foaming cleansers that are rinsed off soon after being applied, she says – except for people who have a history of skin conditions such as eczema.

However, she points out that there is an evidenced-based trend away from using products with SLS that are left on the skin, such as moisturiser or make-up, as it can then be directly irritating.

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Find which products are palm oil-free by using the palm oil-free shopping guide – and learn to spot palm oil’s hidden names with the palm oil-free wallet card. Click here.