SLS & SLES
Posted on 16th September 2020 at 22:30
What are SLS & SLES?
In this article we’re going to talk about SLS and SLES, these two ingredients that are part of our everyday lives.
They are in a large amount of personal care products and cosmetics that we use on a daily basis and we think you should know what they are and what they are used for.
Topic’s we’ll cover in this article include;
What is SLS?
SLS stands for sodium lauryl sulphate, this chemical is also called other names but is essentially the exact same chemical formula, it is also known as ;
sodium dodecyl sulphate
sodium monolauryl sulphate
SLS is a chemical surfactant. It is made of a hydrocarbon chain (palm oil, coconut oil or petrol), attached to an acid (sulphuric) bonded to an alkali (Sodium Hydroxide).
A surfactant is a chemical compound that lowers the surface tension between two materials. In super simple terms, it makes things slippery.
The main reason that it is used is for cleaning products. The reason it is a great cleaner is that SLS is a degreaser. This means that it can break down fats and grease so they are easily washed away.
Sodium Lauryl Sulphate is a compound that has been developed to do the job of the original surfactant, soap. SLS was originally developed as a synthetic detergent to be used in washing powder as it has very good degreasing qualities.
During World War II in February 1942 soap was rationed to save oils and fats for food and food production. This lead to the use of other ingredients in soap that could replace its cleaning qualities.
SLS had been used in washing powders since the 1930’s and had replaced the older methods of natural soap and soda for the cleaning of clothes.
Synthetic detergents were introduced into soap during this period of rationing because the oils and fats usually used to make soap were extremely precious for food supplies.
After the war was over the soaps stayed the same and never reverted back to their natural roots.
What is SLES?
SLES is Sodium Laureth Sulphate, a chemical very similar in make up to SLS. SLES is actually made from SLS that has been put through a process called ethoxylation.
Ethoxylation is the process of reacting ethylene oxide with a chemical to make it less harsh and is commonly used in surfactants in the cosmetics industry.
Ethylene oxide is a colourless gas with a sweet smell. It is primarily used to produce other chemicals such as SLES and antifreeze. It can also be used as a pesticide and sterilizer because of its ability to damage DNA, which is why it is listed as a carcinogen.
The process of ethoxylation has been known to produce 1,4 dioxane as a by-product of the chemical reaction.
1,4 dioxane has been noted as an irritant to eyes, noses and throats in humans and large doses of this chemical has been attributed to liver damage, kidney damage and damaging DNA.
SLES is slightly gentler on skin than SLS but still essentially is very similar to SLS in its cleansing and degreasing properties.
SLES is a slightly less harsh version of SLS which is used in a large volume of personal care products such as soaps, shampoos, shower gels, liquid hand wash, washing up liquid and toothpaste.
Both SLS and SLES are foaming agents, which means they produce a lot of foam or bubbles. Both are used in bathroom products designed to produce lots of foam, including shaving foam and bubble bath.
What is SLS & SLES free?
SLS free & SLES free is a term that you may have noticed on your cosmetics recently. This is because these chemicals have some pretty bad reviews on how they treat skin. If you want the full story on this then it’s coming later in the article but if you need to know now here is the link to that section.
SLS & SLES free means that the product doesn’t contain SLS or SLES, but it can still contain a number of other sulphates or other chemicals which are nearly identical in their properties.
If the product says that it is just SLS free, then it will more than likely contain SLES as although they are extremely similar, they are not technically the same chemical. This is also true for SLES free labelled products, which can contain SLS.
They can also both be replaced with very similar surfactants that do exactly the same job but are widely unknown as they have been recently developed.
Examples of other chemicals used to replace SLS & SLES in your products include;
Sodium C14-16 Olefin Sulfonate
Sodium Cocoyl Isethionate
Sodium Lauroyl Sarcosinate
There are such a large amount of these chemical surfactants, which are being constantly developed by large chemical companies as alternatives to SLS which is the poster chemical of dry skin.
The truth is that all of these chemicals, whilst not being the exact same, are extremely similar in structure and purpose to SLS.
What is SLS and SLES used in?
SLS & SLES are mainly used in personal care products and cosmetics, but they can also be used in a number of other products which may surprise you.
Here is our list of products that use either SLS or SLES and why they are used in the product.
Soap- Both of these chemicals are commonly used in soaps and sometimes both are included in the same product. They tend to be in the cheaper soap products you find in supermarkets and pharmacies. They also tend to be included in bars made with mainly palm oil, which can be an extremely drying and cleansing ingredient in soap, especially if used in quantities of over 40% of the bar.
Shower Gel- Shower gels almost exclusively use surfactants in their ingredients. A shower gel is basically made up of water, surfactant, colouring and scent. The SLS & SLES also have another purpose in shower gel. They act as an emulsifier which allows water and oil to mix easily.
Bubble Bath- Used for its foaming properties and it’s abilities to emulsify fragrance oils into the concoction. A popular product with children, even though according to this study it can be harmful to eyes.
Toothpaste- Used as a foaming agent and to emulsify the ingredients together. This study has said SLS can be linked to mouth irritation and ulcers.
Nicotine Patches- Used to irritate the skin and allow the nicotine faster access to the blood.
Shampoo- Another liquid formulation which commonly contains SLS or SLES, used to clean the hair, but can also strip the hair of the oils it requires to be healthy and strong. There are some ‘sulphate free shampoos’ available but these also usually contain replacement surfactants such as sodium olefin sulfonate’ which is not technically a sulphate but still a chemical surfactant. Basically large companies are replacing bad name surfactants such as SLS with ones that people may not have heard of but do exactly the same.
Shaving Foam- SLS & SLES are both first and foremost cleansers, but one of the properties these chemicals contain is that they can create a lot of foam. This is why they are commonly used in shaving foams, for their ability to create a lot of foam. These ingredients could also be used because they can emulsify the fragrance oil into the water used for shaving foam.
Creams and Lotions- Hand cream, face cream, sunscreen, eczema cream, body lotion, moisturising cream, anti-itch cream, hair removal products just to name a few. The main reason these ingredients are put into creams and lotions is to emulsify the ingredients together and keep them mixed together. Creams are largely concoctions of water and oil, which is why they need to be emulsified together, otherwise they would separate.
Make-up- These ingredients are used to keep the makeup stable and blend different ingredients together.
Why SLS & SLES are bad for your skin
We know what SLS and SLES are and what products they are in. So why are they bad for your skin?
Well these chemicals fall into a chemical group called surfactants. A surfactant is a substance that can bridge the barrier between oil and water.
SLS & SLES break down most fats and grease due to their surfactant qualities. That includes the natural grease that your skin produces called sebum.
SLS & SLES are bad for skin because they strip the skin of its natural grease, which fills the gaps between skin cells. This allows water to escape causing dry skin and eczema.
When you use products with SLS, SLES or any chemically produced surfactant on your skin, hair or body they can cause your skin to dry out, especially if used consistently i.e. washing hands.
Products such as liquid soaps, shower gels and shampoos usually contain the highest concentrations of these ingredients.
Skin naturally loses water and the skins top layer (the epidermis) is the final barrier to the water loss, and allows water to exit at a rate that you can replenish from drinking water or other beverages.
When you wash or apply products with these surfactants, you allow the natural grease which ties the skin cells together to be washed away, which leaves gaps between skin cells, allowing water to escape.
If your skin cannot produce the natural grease fast enough to plug the gaps or is continually washed away, water will escape at a much faster rate than you body can replace in the affected section of skin.
This is why using SLS or SLES is bad for the skin, it allows water loss and leaves the barrier to water loss broken. This can leave you with dry skin or even eczema.
Why SLS free soap is better for your skin
SLS & SLES free soap otherwise known as natural soap is great for the skin because it contains glycerin which is naturally produced in the soap making process.
Glycerin is one of the key ingredients when keeping skin moisturised and soft. This is because it is a humectant which basically means it draws moisture towards it.
You can find out more about glycerin and why it’s great for your skin here.
Soap made in the traditional manner will contain glycerin and this is great for your skin. There are some soaps out there that claim to have glycerin in them and may only have a trace amount in them.
There is one key ingredient to look out for to know if your soap contains glycerin or not. This ingredient is salt, or sodium chloride.
If you soap contains salt, it means that it will probably of had most of the glycerin taken out of it, this is because glycerin can be separated from soap by boiling it in salt water.
Natural soap with glycerin in is truly the best for your skin, it keeps it moisturised and is also a lot gentler than soap made with SLS or SLES.It’s also a lot better than any liquid soap’s as they are largely made up of these harsh chemicals.
One last thing to look out for in your natural soap is if the product is made with palm oil. Palm oil and Palm kernel oil are incredibly drying in soaps and most skin care products.
They are commonly used in soaps because palm oil is the cheapest oil in the world to buy and therefore used by companies looking to make huge profits. Palm oil based soaps tend to be very drying and if they also contain SLS or SLES they are even worse.
We highly recommend using a natural soap, packed with glycerin and not containing palm oil.
The main conclusion that we draw from this information about SLS and SLES is that it is clearly much better for your skin to use soap that is free from these ingredients.
We know they are drying to the skin which can cause dry skin problems and even eczema if you are prone to it.
By replacing your normal sls soap with a natural soap your skin will feel much softer as it will be losing less moisture. It may even save you some money as you probably won’t need to use moisturiser anymore or drastically less than you used before switching.
We also highly recommend staying away from liquid soaps and shower gels as these contain usually SLES, which while being ever so slightly more gentle than sls, also produces small amounts of 1,4 dioxane which is a potential carcinogen.
We hope you’ve enjoyed this article and know more about these ingredients to help inform you to make the best choice for your skin.
If you have any further questions, please leave a comment below and we’ll do our best to answer it!
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