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SLES – Once evil, now Green

April 25, 2010

Sodium Lauryl Ether Sulfate is one of the BAD BOYS when it comes to the Googlepedia of chemicals. That said, this has nothing really to do with Google but it has everything to do with the fact that brand after brand, green group after green group and health scare blog after health scare blog don’t like this chemical.

There seem to be a few reasons why SLES is one of the “THIS PRODUCT DOES NOT CONTAIN……” most wanted so it makes sense to have a quick look.

Surfactants are our cleaning work-horses found in soap, shampoo, face washes and bubble bath

1) It sounds chemical and chemicals are not good.

This seems a little flippant but in cosmetic chemistry the INCI (global protocol for naming ingredients) matters. The public don’t want ingredients that sound bad and so companies go to great lengths to get a ‘good’ INCI name for their chemical. Before you scream “WHAT? So they are putting in mercury and calling it fairy floss” that is not true. The INCI name has to relate to the chemical structure but for some chemicals the manufacturer has a degree of choice and will often opt for the least ‘chemical’ sounding name. SLES d0es sound like a chemical as it makes no reference to flowers, trees, fairies or naturally derived oils.

2) SLES is used in industrial cleaning products because it is so harsh.

Well, it can be used in industrial cleaning as it is relatively cheap, readily available and a good foamer and cleaner however the grade that get’s used in cosmetic formulations will be the cleanest and finest of the product.  Consider salt as an example,  we use salt to grit our roads in winter but try serving that on your chips and there would be uproar – same chemistry, different grade of purity. When SLES is formulated into a cosmetic product – shampoo, bubble bath or face wash it has usually been blended with one or two more surfactants (SLES is a surfactant = cleaning agent) to give a milder, more cost-effective and higher-foaming blend.

3) SLES is a very irritating chemical.

SLES has been dragged down by its cousin Sodium Lauryl Sulphate which is a strong irritant. SLES is much milder than SLS although it can still irritate broken skin.   The Cosmetic Cop wrote a good review on the harshness of SLES  and I wrote about it back in Feb last year on this blog.  In a nutshell while SLES is not the most mild surfactant in the world (it is a very effective degreaser which means it can clean far too well for those with sensitive or broken skin BUT it is not going to rip your skin off unless you use it neat.

4) SLES gives you cancer.

This stems from the small amount of 1-4 dioxane that can be present in chemicals that have been ethoxylated.  However, the quantity detected in finished products can be as low as 1-2 parts per million and must be below 30 ppm – levels that have been declared as causing no risk of cancer by government and independent testing facilities. That said, some companies do prefer to follow precautionary principles and avoid any ingredient that has a potential to cause problems which is fine but following that rational should lead to the removal of a whole lot more ingredients, products and packaging.  It is also important to keep in mind that our ability to detect very small amounts of impurities is getting better every day. The fact that we can now pick up minute traces of chemicals doesn’t mean that the world is becoming MORE toxic – we were just suffering from ‘what you don’t know can’t hurt you’ before whereas we are now suffering from “a little information can be a bad thing” now.

5) SLES is made from petroleum and is therefore environmentally damaging.

SLES can be synthesised in a number of ways including by a process that uses petroleum as one of it’s starting materials (feed – stock). Petroleum is also often used to manufacture the ethylene oxide which is needed to make this chemical active. However, one chemical manufacturer Rhodia has now come up with a way of making SLES without petroleum!

The backbone of the chemical can be sourced from palm and  the ethylene oxide from sugar cane to produce a ‘natural’  and less carbon-intensive surfactant that has a wide range of uses.

BUT STOP. Isn’t palm oil bad too?  Palm as a feedstock for the chemical industry has gotten a bad press due to the massive deforestation that has happened in palm growing areas and the displacement of thousands of Orang Utans and other forest animals.  I have discussed the issues with palm oil in this blog before here , here and here. We are encouraged by some charities to boycott palm and many companies have been asked to re-formulate to avoid palm based ingredients.  Good news? NO.

There is an argument for not producing ANY of these chemicals in the first place but this is somewhat unrealistic in this day and age.    Boycotting palm and moving to cotton / corn / soy or coconut is probably also going to turn out to be an “EMU” approach to solving this problem as all of these resources have to grow somewhere and you may be in danger of cutting off your nose to spite your face.

By the way, this surfactant has always been biodegradable and as it is shipped in bulk it is probably one of the most low-emission surfactants to transport and store.  An inconvenient truth perhaps?

So is this new SLES good or evil?

Health wise this product is no worse than the ‘old’ but cosmetic grade product and while that passed general safety tests for the purposes it was employed, it was not good enough for some. 

Environmentally this surfactant demonstrates the chemical industries willingness to embrace  “green chemisty” and provide new solutions to old problems. They took out the petroleum and gave us a cost-effective natural work-horse.  Most ‘natural’ certifying bodies should now scrub that clause that says “thou shall not use ethoxylated surfactants”  but I doubt that many will as the myth is far more sexy than the reality.

Overall the right of the public to choose the products that they buy and the ingredients that they back remains and in a touchy-feely “cosmetic” industry their remains no right or wrong reason for making that choice. However,  the industry is based on science and a scientific review would have to give this product a big tick.

It’s complicated but we are getting there.

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