What the SLS?

I really shouldn’t write a blog… especially posts addressing my ethical dilemmas. Every time I do, I just open up a whole new can of worms for myself. The first time it happened was about knitting yarn ethics… to such an extent that I actually ended up making a whole can of yarn worms:


Yesterday’s post was about single-use plastics, but initiated a discussion about shampoo, leading me to start looking at various packaging-free or reduced packaging shampoo options. One of the manufacturers suggested was Lush, who make shampoo bars that some commenters really like and a bit of internet research revealed that there are several ‘green’ writers who endorse these products (Ecohustler, for example). So, I headed over to the Lush website to look at what they have to offer. I know that some Lush products are very highly scented and this is no good for me because perfumes make me sneeze (a lot), so I thought that I would look at the ingredients to see what they were likely to smell of. And at this point, I discovered that all Lush shampoo bars list Sodium Lauryl Sulfate (SLS) as an ingredient.For example, the ingredients of the Lush Trichomania shampoo bar are:

Sodium Lauryl Sulfate, Stearic Acid, Creamed Coconut, Glyceryl Stearate & PEG-100 Stearate, Cocamide DEA, Soya Lecithin, Perfume, Vetivert Oil

Now I have heard that SLS is not good and I’m not a big fan of products that contain soya and what on earth are PEG-100 Stearate and Cocamide DEA? Well, apparently PEG-100 Stearate is an emulsifier and Cocamide DEA is a surfactant that either dissolves grease or is a foaming agent (depending on which web site you read). The latter is now illegal in California, as it is considered a carcinogen. As for SLS, there is conflicting information on the web, the web site SLS Free says that

Sodium Lauryl Sulfate (commonly known as SLS) is a widely used chemical in personal hygiene products, along with Sodium Laureth Sulfate (SLES) and Ammonium Laurel Sulfate (ALS).

SLS is essentially a foaming agent in products such as soaps, detergents, shampoos, toothpastes and detergents along with some industrial cleaning products such as engine degreaser, floor cleaning products and car wash. It is also widely used as a skin irritant when testing products used to heal skin irritations.

They go on to say that

At this point in time there is no scientific evidence that links the use of SLS to Cancer.


In addition to skin irritation, there are studies that point to residual levels of Sodium Lauryl Sulfate in the brain, lungs, liver, and heart. These levels follow the use of SLS used externally on the scalp and skin, and in the mouth as an ingredient in toothpaste.

There are some findings that link the ingredient to a hormone imbalance. Symptoms such as PMS and PMT and menopausal symptoms are tied to hormone levels. There has been a lower rate of male fertility reported in some cases, particularly in western countries however this is as yet unsubstantiated. Because SLS mimics oestrogen, it is possible it may play a role in these types of health issues.

In contrast, the Personal Care, Truth or Scare website is much more reassuring, stating that ‘by all green standards SLS is the perfect ingredient’ and there is no problem using it in ‘wash-off’ products. I’m not convinced about anything being ‘perfect’ and would take this claim with quite a pinch of salt considering that I subsequently discovered that much SLS is made from palm oil, at least according to the Say No to Palm Oil website, which rather shatters its green credentials. Lush are quiet about what their SLS is made from… it could be coconut oil, but I simply don’t know.

Single-use plastics, but what's inside?

Single-use plastics, but what’s inside?

Anyway, with all these questions about ingredients in the Lush soap bars, I thought I’d look at another product that yesterday’s readers had suggested, namely Faith in Nature shampoo. Now, the problem here is that using this would not cut out single-use plastics, but could significantly reduce them by buying in bulk. I already use FIN aloe shampoo in small bottles and could easily convert to buying it in 5l containers, so what is in that? The ingredients are listed as:

Aqua, Ammonium laureth sulfate, Maris sal, Aloe barbadensis leaf juice, Polysorbate 20, Cocamidopropyl betaine, Citrus limon peel oil, Citrus aurantifolia oil, Melaleuca alternifolia leaf oil, Potassium sorbate, Sodium benzoate, Citric acid, CI 75810, Citral, Limonene

Well, I know that Aqua is water, and I’m ok with that , apart from the transportation issues. The words that I have italicised are botanical names of plants (trust me, I’m a plant ecologist!) and I’m happy with using the essential oils from those, and maris sal is sea salt. But what about that Ammonium laureth sulfate? It sounds awfully like Sodium Lauryl Sulfate to me. Back to Googling again…

I found what looks like a really well researched page on the Green People website (I sometimes use their shampoo too) that answers the question (and gives lots more info on SLS). They say:

There are several other surfactants with similar names to SLS – in particular ammonium lauryl sulphate and ammonium laureth sulphate. Although these sound very similar their molecular structure is significantly different and they do not have the same potential to irritate the skin. Also, because their molecules are larger than those of SLS, they are not able to pass through the skin and therefore cannot be absorbed into the body in the same way. Because of these differences, ammonium lauryl and laureth sulphates are considered to be milder and safer alternatives to SLS.

So that sounds like a better option. As to the other ingredients Polysorbate 20 is another emulsifier, and can be contaminated according to this website. I guess any ingredient can be contaminated and we have to choose whether we trust the supplier. Cocamidopropyl betaine is a surfactant (giving the shampoo it’s lathering and cleansing properties) and can cause skin irritation, but is not considered a particularly ‘bad’ ingredient according to the notes at the bottom of the Chemical of the Day website from Bumblebee Organics. Potassium sorbate is a preservative and can be an irritant, but is used in food as well as personal care products (more details here); similarly, sodium benzoate is a preservative and whilst there are some concerns about its use in foodstuffs, it is reportedly safe in skin care products. Citric acid is fine with me and it turns out that CI 75810 is chlorophyll… clearly used to colour the shampoo. Both Citral and Limonene occur naturally in citrus as well as in other plants and are used as fragrances.

So, on balance, the Faith in Nature shampoo seems better than the Lush in terms of ingredients. But there is more to consider: liquid shampoo contains lots of water and thus adds to transportation costs compared to solid shampoo. The liquid shampoo is also sold in those pesky single-use bottles. But, by buying it in 5l containers, the amount of plastic is reduced and I get a sturdy receptacle that I will use again in the house or garden.

Yet again, when making ethical choices there isn’t a simple ‘right’ answer. I just wish, like Rachel who commented yesterday, I had a herbalist down the road who made their own and would refill a bottle for me… lucky Rachel!


I should say that all this research relies on finding reliable websites. I have seen many sites that appear to be scaremongering and many that seem to be marketing specific products. I have tried to use sources that look sensible, but I may have been duped! It appears that if you type the name of any chemical into Google, you can find sites telling you that it is a carcinogen or an irritant… I guess most things are in certain circumstances or high enough concentrations. Certainly plant essential oils can be really dangerous if used inappropriately. If you find a site that seems to be well referenced (like the Green People page I mention above) I think you can be more confident that it’s factually correct, but you never know. Researching this sort of thing is a complete minefield and very time-consuming, but hopefully I have started to present some useful information for you to make some informed choices.

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  1. With regards to Essential Oil Safety it is worth getting Robert Tisserands book of that name. It was on the reading list for my aromatherapy training. I should probably check to see if there is a more up to date version as I use a few oils that weren’t commonly available then.


  2. Thanks for this post and the interesting information/research 🙂

    Apart from the hygiene products, considerations on the ethical side of yarns is an important question that I often pondered myself. Similarly we could say of clothing in general.

    Firstly, I would try to re-use what already exists (second hand or vintage) to avoid further unnecessary production of material. Further I would prefer natural fibres to acrylic ones.

    Although, there could be a never-ending debate about which one is less “green” (environmentally friendly). Natural fibres are usually easier to dispose of, once the item is no longer in reusable state; plus they’re not based on oil and may use less chemicals. On the other hand, ruminant animals notoriously are an important source of green house gases.

    Bottom line, I think reusing is always the best way to go. With regard to yarn, I started buying old items from destash, to keep the production strain on the environment to a minimum.

    What do you think?


    • I have spent many hours thinking about textiles and yarns… processing, transportation, manufacture. I try to stick to natural fibres too, to wear clothes until they fall to pieces, to repair when possible and to compost as a final ‘use’.
      In addition to the link in the post, you can read some more of my musings here: https://thesnailofhappiness.wordpress.com/2012/07/05/eco-knittin/
      again, there is no simple ‘right’ answer, but reducing consumption always helps


      • Thanks again, I completely agree.

        I’m just making some draught stoppers these days (my flat is very draught prone), and I had the idea to use old ragged clothes as a filling, instead of ordering either synthetic or woolly filling).

        There’s probably always a further re-use that can be made with any material at hand 😉

        Thanks again for all your research and posts, they’re a very good read!


  3. Interesting post Jan, yes i am very lucky to have such a wonderful herbalist just down the road xx


  4. When I read this post I thought of the brand of soap the kids and I use every day called Sukin organics. It is SLS and SLES free, no this that and the other, and apparently vegan and carbon neutral. They do body wash, shampoo, conditioner, creams and all other things smelly. 🙂

    I wasn’t going to recommend it to you as sending a bottle across the planet would completely defeat the purpose altogether! However, I noticed this morning the kids had turned the bottle around and there it was, a small address for the uk on the bottom of the bottle. It must be fate! 😉 I’m not sure if it is what you after but I thought you might be interested in looking into it. Cress ltd Sudbury.


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