This is essentially a recycled and updated post from 2011. Recycling is good, right!?
Build-up from hair products is usually 2 things:
- Oily residues like actual oils and butters, creamy ingredients like Cetyl alcohol and other emollient ingredients.
- Cationic ingredients that bond to the hair. When they're good, they're very good and when there is too much, you feel "build-up."
Here I’m referring to 2 classes of chemicals: Quaternary cationic surfactants and cationic polymers. First off, cationic means something has a net positive charge (+). Hair has a net negative charge at the pH environment in which it usually exists (somewhere between pH 4.5 and 5 is average). Opposites attract (positive and negative) when it comes to hair and conditioner. More-damaged hair (the ends, heat-styled, sun-damaged, chemically relaxed, permed, highlighted) has more negative bonds and will bond with or "adsorb" more cationic ingredients. But it also loses them more quickly.
Low porosity hair has fewer negative charges to adsorb conditioners and cationic ingredients. It is also more likely for the owner of low-porosity hair to notice / experience "product build-up."
Quaternary cationic surfactants (and cationic polymers) are the real “conditioners” in hair and skin products. They bond to hair (and skin). Cationic polymers in styling products (Polyquaternium-4, for example) also bond to hair to form a film that provides hold and humidity resistance.
Build-up tends to look like you'd rubbed your hair with a balloon (static-y, flyaway, self-repellant). Or it can look sticky and stringy. Or dull and matted. Wavy, curly or coily hair might not pull together in it's proper curl pattern when you have build-up. Straight hair might get stringy or increase in volume (not necessarily in a good way).
Quaternary Cationic Surfactants:©Science-y Hair Blog 2013
Quaternary cationic surfactants include ingredients such as:
Behentrimonium chloride, Behentrimonium methosulfate, Cetrimonium bromide, Cetrimonium chloride, Stearalkonium chloride, Dicetyldimonium chloride, Guar hydroxypropyltrimonium chloride.
Most of these are not water soluble, but water-solubility doesn’t much matter because they’re bonding to your hair. Imagine magnets – the positive end of the quaternary cationic surfactant bonds to the negative hair. The thing is, it’s a pretty tight grip. Think giant magnets. Electromagnets that are used in scrap metal yards. This is known as “substantivity” in cosmetics chemistry.©Science-y Hair Blog 2013
Having these ingredients on your hair is not a problem in itself. Not unless you experience symptoms of build-up. Shampooing is not always a solution because most shampoos are based on anionic (negatively charged) surfactants. And now you’re saying, wait, that should mean that it should remove the cationic stuff because it has a negative charge and opposites attract. Yes! But the hair holds the cationics too tightly. The shampoo (anionic) may not be a big enough “magnet” to remove the cationic (conditioner or polymer).©Science-y Hair Blog 2013
Cationic Polymers include polyquaterniums (Polyquaternium-4, Polyquaternium-10, Polyquaternium-11, for example). These ingredients are very often water-soluble, but that’s not terribly relevant because they also get a tight grip on hair and so they don’t rinse off. Polyquaterniums are used in shampoos and conditioners to provide lightweight conditioning and frizz-prevention and used in hair styling products because they form stiff films over the hair to provide firm hold. They can add body to fine hair because of their hold/fixative-providing and film-forming behavior.©Science-y Hair Blog 2013
Polyquaternium 4 gives strong hold and may be easier to remove than Polyquaternium 10 or 11, in other words, it is more possible to pry it off with water and a detergent. Certain proteins and quaternary cationic surfactants can bond more firmly with hair than does polyquat-4. There are many other Polyquaterniums (with other numbers following them -7, 37, 44, 67…), all of which will bond more or less tenaciously to hair. Polyquaternium 10 may also be easier to remove than some of the others, there is even a “low residue” version of this polymer available, although it is doubtful that this distinction would be revealed in an ingredient list.
Concentration is important. The more polymer there is, the more the possibility for build up. If you are looking at a product with 20 ingredients and a Polyquaternium is ingredient #15 or #30, there isn’t much in there. But if it is ingredient number 3 or 4, there is more present. And even that is misleading because the actual percentage could be pretty low. So it’s best to judge by whether or not you get consistently good results from a product.©Science-y Hair Blog 201
How to Deal With Build-Up
There are 2 ingredients to look for in a shampoo to remove cationic build up most effectively:
Alkyl sulfates and alkyl sulfonates are anionic, and are better at removing cationic soils than other “sulfate” detergents (this has been demonstrated through controlled testing).
Look for C14-16 olefin sulfonate or...
Alkyl sulfates: Sodium lauryl sulfate and Ammonium lauryl sulfate, Sodium coco-sulfate.
These are deep-cleaning detergents, but can be diluted with water for a milder product. They are good de-greasers for removing excess oils (or silicones). The small molecular size means the product can penetrate skin and hair - so there is potential for drying and irritation. Formulation matters!!! When there is more detergent (higher concentration), the product will be more "stripping." When there are fewer mildness-increasers like humectants, or ingredients to make the product look pearly and translucent, the formula will feel less pleasant to use.
Also look for Sodium polystyrene sulfonate. This ingredient helps remove 25% more cationic soil than rinsing alone or shampooing (even with a “sulfate” shampoo). It is not a detergent.
Shampoos with the ingredients mentioned:
Chi Infra Moisture Therapy Shampoo
Pure & Basic Clarifying Citrus Shampoo (C 14-16 olefin sulfonate and Sodium polystyrene sulfonate)
Nexxus Phyto Organics Kelate Purifying Shampoo (Sodium polystyrene sulfonate)
Pureology Safeguard Your Color Purify Shampoo (Sodium polystyrene sulfonate)
Ouidad Superfruit Renewal Clarifying Shampoo (C 14-16 olefin sulfonate and Sodium polystyrene sulfonate)
Warren Tricomi Style Smoothing Shampoo (Sodium polystyrene sulfonate)
Kinky Curly Come Clean (C 14-16 olefin sulfonate)
Kenra Volumizing Shampoo (C 14-16 olefin sulfonate)
Trader Joe's Refresh (Body Wash), (C 14-16 olefin sulfonate)
Trader Joe's Tea Tree Tingle Shampoo (C 14-16 olefin sulfonate)
J. Soc.Cosmetic Chem.,43, 259-273 (September/Octobber 1992)
J. Soc.Cosmetic Cthem.,40, 205-214 (July/Augus 1989)
Removal of Cationic Buildup From Keratin Surfaces By Sodium Polystyrene Sulfonate
Presented at PCIA Shanghai - March 2002