Everything you need to know about surfactants
If this term doesn't mean anything to you, then it's high time to look into it. For what ? Because surfactants represent up to 30% of the ingredients in a liquid shampoo and up to 70% for a solid shampoo.
These are the most important components of a shampoo, their backbone. This is why at Loubaïo we have chosen to use the best, the gentlest: glutamates.
We will explain everything to you !
What is a surfactant used for?
Surfactants can have different functions, here are the main ones:
- Detergent : cleans, simply.
- Foaming : produces foam but be careful, as we explained in our article on foam ( find it here ), it has nothing to do with washing power.
- Conditioning : facilitates detangling of hair.
- Wetting : allows better spreading of the liquid.
- Emulsifier : allows two materials to mix (water with fatty substances for example).
- Dispersant : prevents the agglutination or deposition of particles in a fluid.
Zoom on the structure of a surfactant
A surfactant is made up of a hydrophilic head (which likes water) and a hydrophobic tail (which does not like water but loves fat).
The principle is very simple: the fatty substances will be “grabbed” by the tail of the surfactant, while the head clings to the water molecules. This therefore allows the evacuation of fatty substances during rinsing.
The different types of surfactants
Surfactants are classified into four groups, depending on the electrical charge of their “head”.
Cationic surfactants : quaternary ammoniums
They are low foaming, low detergent and tend to weigh down the hair. And to make matters worse, they are rather bad for the environment (very polluting manufacturing).
Anionic surfactants : sulfates
The most common: they foam very well, are good detergents, inexpensive but irritating and drying. They are very often used in household products (and at Loubaïo we don't really want to have them on our heads...).
They are mostly bad for the environment (from petrochemicals).
Here it is already a little better: they are not very irritating and some can be of natural origin, but not all are perfect (like Cocamidopropyl Betaine which is controversial, not to be confused with Coco Betaine).Non-ionic surfactants
The cream of the crop, the ones we use in our shampoos! They are very soft but foam a little less. Most are of natural origin and even biodegradable.
Too much detergent surfactant can be harmful to both your hair and scalp:
- For your hair: in reaction to too much detergent, your hair “overproduces” sebum (natural protection of your hair) and becomes oily more quickly. Not to mention the damage to the fiber in the long term.
- For the scalp: irritating power potentially leading to dandruff, itching and other imbalances...
Classification of surfactants frequently used in cosmetics
In order to better understand the INCI lists of your cosmetic products, here is a summary (non-exhaustive) of the main surfactants used in cosmetics.
To avoid :
- Sodium Lauryl Sulfate (the famous SLS)
- Sodium Laureth Sulfate (SLES)
- Sodium Myreth Sulfate
- Sodium Oleth Sulfate.
- Amonium Lauryl Sulfate (ALS, authorized by the COSMOS ORGANIC standard… ☹)
- Amonium Laureth Sulfate
- Cocamidopropyl Betaine
- Sodium Coco Sulfate
- Sodium Lauroyl Sarcosinate
- Disodium Lauryl Sulfosuccinate
- Disodium Laureth Sulfosuccinate
- Disodium Cocoamphodiacetate
- Decyl Glucoside
- Coco Glucoside
- Lauryl Glucoside
- Sodium Cocoyl Glutamate
- Disodium Cocoyl Glutamate
- Sodium Lauroyl Glutamate
- Sodium Myristoyl Glutamate
- Sodium Cocoyl Isethionate (SCI)
- Sodium Lauroyl Methyl Isetionate (SLMI)
A brief aside on solid shampoos
When they are not soaps (we will explain this to you in a future article), solid shampoos obviously contain surfactants.
Here is a short presentation of those that you can find in the INCI:SCI: the vast majority of solid shampoos with surfactants use SCI. It is gentle, foaming, disperses well and is not very expensive.
But - because there is often a "But" - its manufacturing is very polluting. Reason why he did not obtain his COSMOS certification. So we won't use it.SCS: it is not one of the mildest surfactants and its production method is polluting. But unfortunately it is authorized by the COSMOS ORGANIC standard and its price is very low.
It is therefore frequently used in solid products by Organic/Natural brands to obtain the label (COSMOS ORGANIC) at low cost... Not pretty pretty ☹. Obviously excluded at Loubaïo!
SLMI: cousin of SCI, this surfactant appeared a few years ago. It is supposed to be gentle and less polluting than SCI, but there are no reliable studies to date, apart from the manufacturer's data. It is also not accepted by COSMOS ORGANIC certification. In short, doubts remain as to its harmfulness for the environment. So we won't use it.
Why we chose to use glutamates
The acylglutamate family represents, in our eyes, the best surfactants to date!
Historically discovered in Japan in the 1970s, they are made from amino acids (glutamic acid) and fatty acids, two essential physiological components of the skin and hair (keratin contains up to 15% acid). glutamic acid).
They give a creamy foam, quite characteristic (like the one you get with our colored hair shampoo).
- These are the mildest surfactants:
Screen print from the Cosmetics Obs article dedicated to acylglutamates . This graph shows the results of a test measuring the eye irritation of surfactants, glutamates are the two histograms on the right.
- They are non-lipid-removing: glutamates have selective cleansing power, they eliminate sebum without attacking the lipids of the epidermis, essential protection of the skin.
- They have a moisturizing effect: Sodium Cocoyl glutamate (present in our shampoos), for example, significantly improves the moisturizing effect of rinse-off formulations.
- They are environmentally friendly.
- Their cost: unsurprisingly, they are the most expensive on the market (up to 10 to 15 times more expensive than other surfactants) which explains their low use/low concentration in shampoos.
- Their origin: historically invented in Japan, most suppliers come from this country.
If you only had to remember three things:
- Surfactants are at the heart of a shampoo, they will determine its washing power, foam and many other characteristics.
- Unfortunately, it's a big family in which we find very nice cousins and much more aggressive ones, for you and for the planet.
- The cost differences between surfactants are very significant, so brands very often choose price rather than quality and respect for nature. You will have understood, we are not in this category!
There you have it, you know everything you need to know to analyze your shampoos with full knowledge of the facts. So now, on to your labels!