Ingredient Watch: SLS and SLES

Unless you’ve been living under a rock, you’ve no doubt heard lots of noise about a common cosmetic ingredient: Sodium Lauryl Sulphate or its sister Sodium Laureth Sulphate, aka SLS or SLES. It seems pretty much every cosmetic company under the sun has taken to producing a shampoo that’s free from either of the two ingredients. Many companies swear by the occlusion making it a huge point of difference.

Why?

First – what are they? They’re surfactants, they strip the skin and hair of oil making it ‘clean’. They are also frothy ingredients, for many years many a housewife wouldn’t trust her dishwashing liquid if it didn’t produce the telltale cleaning bubbles – the same goes for our shampoo, most of us want to see a good, generous lather. SLS and SLES have also been accused of leaching hair dye from our gorgeous locks so to use products with very low amounts or none at all is considered a smart move for those who wish to preserve their colour for longer. It’s a catch 22 – to get good clean locks you need to remove oils and surface dirt, but you might also lose colour too.

Cosmetic chemist and editor for Realize Beauty, Amanda Foxon-Hill explains their purpose well here:

‘Sodium laureth sulphate and sodium lauryl sulphate are two of the most cost effective surfactants for personal care manufacturing. They are added into products to help them to emulsify dirt. They do this by using their chemically modified heads to attract dirt from a surface and then drag it away in the foam that is created as a bi-product of the emulsification process.  SLES and SLS are both ANIONIC surfactants which means that they have a negative charge on their heads. Surfaces such as the hair, skin and often hard surfaces are positively charged. This means that the surfactants are attracted, like a magnet to the dirt!’

The problem is that SLS can be irritating. ‘Can they cause or worsen eczema?  Yes they can. SLS old style is very irritating as it is so good at stripping the skin of oil, that is why it is rarely used now.  SLES is not so bad and when formulated correctly can be quite acceptable but it is often replaced by milder cleaning agents in products for dry skin.’

She’s written a fantastic article which goes into the background of both ingredients (interestingly enough they are derived from coconut or palm oil but can’t quite be considered natural  because as Amanda says, ‘the bit that makes sodium laureth sulphate useful to cosmetics is the ethoxylated head. This is produced synthetically.’ )

So are they really that bad? Well, they’re not cancer causing and there has been so much research and development that in the very small amounts that they have been used in products they shouldn’t be irritating – however – for some people they are. There’s also a concern that during the process of creating SLS it’s been mixed with a harmful ingredient Dioxane. If you suspect that you are try using a product without for awhile to see if it makes a difference – but remember that it’s not just your humble shampoo – you will find SLS or SLES in many household products. Consider finding products with just SLES – the lesser irritating of the two.

Is there a natural alternative? I asked Nigel Luty from Holistic Hair, who also appeared on the show and he replied by email with this:

‘I think the point being is that in all formulations that are quality brands, the percentage of sulphates compared to the sum total is marginal and extremely unlikely to cause a problem. We use an alternate form of foaming agent in Holistic hair‘s shampoo which is a succinate and a sarcosinate, which have long been regarded as a natural alternative. You can reduce this even further but the effectiveness of the cleansing agent becomes compromised and the hair will not get any benefit.’

There’s a lot of scaremongering on the internet and it really depends who you talk to – natural websites will paint a very unfavourable picture of SLS and SLES. But for someone who does get irritation and ezcema and suspects that SLS might be the cause, try avoiding it for awhile and see if that helps. Seek the advice from a dermatologist or doctor to get to the root of the problem.

Tamsin xo