Saturday, July 30, 2011

Cationic Compounds in Cosmetics

The Good, The Bad, The Weird (And the extremely long-winded post)

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). This charge is mostly because of it’s composition, although damaged hair has more potential bonding sites (negative charges) than less-damaged hair.

I fear I’m about to give the impression that these ingredients are bad for your hair. They are not, in fact, they are responsible for silky, smooth, lustrous hair that holds a style. They help define waves and curls and protect damaged hair/protect hair from damage. They can prevent flyaway hair and the high fluff/frizz factor that comes with wavy and curly hair. What? You have straight hair that frizzes? Then no, you don’t have completely straight hair – you have some waves. These ingredients can be more of a problem for people who do not shampoo their hair often, or who have fine, soft hair, but as you’ll find, shampooing and cationic products is a goofy bit of chemistry.

Quaternary cationic surfactants (and cationic polymers) are the real “conditioners” in hair and skin products. They bond to hair (and skin), whereas most other ingredients in, say, a conditioner are emulsifiers (mix oil and water), thickeners, emollients (oils) moisturizers. These may soften and even penetrate the hair, but they don’t bond to the hair shaft.

Most of us played with magnets in school when we were kids. You’ll recall that the “positive end” of a magnet would attract the “negative end” of another, but repel other positive ends. Opposites attract, likes repel. Thus a cationic (positively charged) conditioner has an electrostatic interaction with your negatively charged hair and it sticks to it (adsorbs). Cationics also resist rinsing off both while wet (as in freshly-applied conditioner) and after drying.©Science-y Hair Blog 2013

This is usually a good thing, starting afresh with completely stripped hair isn’t something that would look or feel very nice. Having those ingredients in a formula reduces damage-provoking friction, with the end result of stronger hair.  But have you ever combed your hair or, for wavy and curly-haired people, scrunched or just touched your hair and noticed that your hair was repelling itself? As though you rubbed your head with a balloon? NaturallyCurly.com user Pedaheh coined the brilliant phrase, “conditioner cling” to describe this phenomenon. Like static-cling-y clothes just out of the dryer. This happens frequently with fine hair, which has a lot of surface compared to it’s inner bulk and therefore holds a lot more conditioner relative to its weight than does a thicker hair. How are cationic ingredients involved?©Science-y Hair Blog 2013

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 begin to find your hair weighed down, not curling if it should, or repelling itself. 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

Which ingredients are “stickier?” Cetrimonium chloride, in low concentration, is thought to be less tenacious than other quaternary cationic surfactants, whereas Cetrimonium bromide is considered highly substantive to hair. Behentrimonium methosulfate (hey allergy people – Behentrimonium is made from canola oil, so unless you’re allergic to mustards, it may work for you) is highly substantive to hair, as is Behentrimonium chloride. You may dislike an ingredient in one formulation and love it in another. The chlorides exhibit especially great substantivity to hair as demonstrated by not rinsing out, by prevention of fading in colored (dyed) hair, and by reducing the force needed to comb hair. But is this simply because the “methosulfates” are relative new kids on the block and haven’t been compared much side-by-side?  Could be.©Science-y Hair Blog 2013

One thing “methosulfates” have going for them is that they are less irritating to the skin than chlorides, so sensitive people might want to look for Behentrimonium methosulfate instead of Behentrimonium chloride or Cetrimonium chloride in a conditioner used to cleanse the hair and scalp, on in a skin lotion. ©Science-y Hair Blog 2013

Worrying which one is “stickier” to the hair than another for these cationic surfactants isn’t as important as considering how much is in a product. If you get build-up easily or have very lightweight, fine or thin hair, then having one of these ingredients quite high up in the ingredient list of a conditioner may cause it to be too heavy for your hair. These cationic conditioners actually help some of the lipid component of conditioners - fatty alcohols like cetyl and cetearyl alcohol, and possibly oils, stick (adsorb) to your hair. Good for creating softer hair, not so good for baby-fine, already silky hair.

Cationic Polymers:
Cationic Polymers include polyquaterniums (Polyquaternium-4, Polyquaternium-10, 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

Polyquaterniums are lightweight, but can lead to build-up. Your gel may feel as though it rinsed out, but you’re left with microscopic cationic “soil” (residue) in your hair.
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, 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 2013

How to Deal With Build-Up
You may experience build-up from these products which you might consider tackling with a detergent such as Decyl or Lauryl glucoside (Polyglucosides) or Cocamidopropyl betaine detergent. This isn’t about “sulfate free” shampoo so much as that these detergents are non-ionic or amphoteric (can act either cationic or anionic). Why? Because (and this is where it gets weird), using an anionic shampoo does not do a very good job of removing cationic “soil” and the presence of cationic soil may increase anionic build-up on your hair. (If you wash your hair with anionic sodium lauryl sulfate and use a conditioner too, you’ll ultimately be left with more sodium lauryl sulfate left behind on your hair). It seems reasonable that if using an anionic shampoo plus a cationic conditioner equals more build-up, then you will have less build-up in your hair if you avoid anionic shampoos. Thoughts? I’d love to hear tham.
©Science-y Hair Blog 2013
Alkyl sulfates or alkyl sulfonates are anionic, but are better at removing cationic soils than other “sulfate” detergents (this has been demonstrated through controlled testing). For example, C14-16 olefin sulfonate detergents. These are deep-cleaning detergents, but can be diluted with water for a milder product.

So if you experience conditioner cling, you find your ployquaternium-containing gel stops working wonderfully for you, or your hair gets limp or greasy with too much conditioning, what can you do?

1) Switch shampoos to avoid anionic detergents or use a detergent-free cleansers (see the recipes and allergy section of this blog for ideas), or use a detergent which is better at removing cationics. Shampoo every other day or daily if it isn’t over-drying to your hair. A hint - diluted shampoo is less drying and easier to rinse out!
©Science-y Hair Blog 2013
2) Use a light touch with conditioner and look for conditioners in which cationic surfactants are not at the beginning of the ingredient list. Avoid conditioners with heavy doses of oils and “butters” like shea butter.
©Science-y Hair Blog 2013
3) Look for shampoos including Sodium polystyrene sulfonate. This ingredient helps remove 25% more cationic soil than rinsing or shampooing (even with a “sulfate” shampoo).
©Science-y Hair Blog 2013
4) Use sugar scrubs or baking soda scrubs (sugar mixed with oil, baking soda mixed with a little water to form a paste) massaged into your scalp and hair. This is for gentle abrasion! That which we cannot remove chemically, we can often remove physically. Following a baking soda scrub with a clean water rinse, and then an acidic rinse helps hair return to it’s normal pH (baking soda is alkaline). A cup of water with a tablespoon of vinegar (white or apple cider) or with 1/8 teaspoon of citric acid instead of vinegar will do. A scrub like this is not as damaging to your hair as is brushing and combing, using high-heat appliances or teasing.
©Science-y Hair Blog 2013
5) If you are only rinsing your hair and scalp between shampoos, skip conditioner on some occasions if you don't need it for detangling.

Shampoos with Sodium polystyrene sulfonate:

Pure & Basic Clarifying (Lite) Citrus Shampoo
Avon ADVANCE TECHNIQUES Body Building Shampoo
John Frieda Blonde Highlight Activating Shampoos
Pureology Serious Colour Care Purify Shampoo
Alterna LIFE Solutions Clarifying Shampoo
Carol's Daughter Rosemary Mint Purifying Shampoo
Paul Brown - Clarifying Shampoo
Ouidad Superfruit Renewal Clarifying Shampoo
  

Sources:
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

17 comments:

  1. Whoa...my head is spinning. I've often wondered about my hairs repelling each other. Must be due to my hair being fine.

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  2. Wow! THis makes sooo much sense. Ever since i started the modified CG method my hair gets squeaky. Even when i stopped using a gel with Polyquats. I thought it was the shea in SM retsorative conditioner but then i switched to Desert Essence Coconut conditioner and even though i clarify with HE naked clarifying conditioner once a week to 10 days I still get the build upy squeaky feel. I was moisturising and sealing my hair after washing so it didnt make sense that the squeaky feel was from dry hair.
    Thankyou soooo much for posting this. I had a feeling it could be B.methosulfate and chloride buildup which is high in both these conditioners(2nd in coconut and 5th or 4th in SM) . I will now rotate between a BTMS free or lower list conditioner. Also i wilk look into the ingredients in shampoos you mentioned. Thanks again!

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  3. A question. Would a baby shanpoo with Decyl Glucoside suffice to remove cationic+sulfate buildup which i think i have or should i go for the Sodiun olefin sulfonate?
    Also what are your thoughts about Sodium sulfolaureate? I think that's the name and it was in Finesse hypoallegenic shampoo which i liked but i wont repurchase unless I am sure it does a good job of removing quats and cationics.

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  4. IAGirl i clarified with my husbands Neutrogena TGel that contains Sodium olefin sulfonate and my hair hasnt looked this good in a year! Moreover my scalp is CALM. think its gotten rid of allll the BTMs and quat buildup. It doesnt feel dry though ive heard it can be drying. I did prepoo my hair with olive oil before.
    How regularly can i use this without drying my hair out? Thankyouuu soo much for sharing this. You saved me a lot of stress and worry.

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    1. I'm replying to this comment, but I read your previous one. Decyl glucoside won't remove build-up from cationic ingredients. It's non-ionic. When it's very concentrated, it can still be harsh and drying, but it lacks any interference with charges. It's a good detergent, (removing dust, etc.) but not a good de-greaser.
      Hey - that's great about the Neutrogena T-Gel! Always great when you find a shampoo that gets your hair clean but not too clean and makes your scalp happy as well!
      I don't think it's a terribly strong shampoo, though it could dry hair out a bit. By using an oil prepoo when you need it or have the time and paying close attention to how your hair looks and feels, you should be able to use T-Gel as often as your scalp needs it. If you're washing your hair frequently, it tends to need oil treatments or deep conditioning or protein more often than if you wash infrequently (that makes sense when I'm thinking it in my head, anyhow). So keep up with those things. The scalp comes first! Good luck!

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    2. Ok. Can you please give ne suggestions for cationic surfactant free or lower amount cationic conditioners that would detangle decently if not a lot and moisturise. I know Suave naturals and v05 have fewer in amount but the chemicals make my scalp itch.
      The only one i found online is California baby conditioner . Have you tried it? Are there any others? I dont mind water soluble or light silicones like Amodimethicone.. preferably unscented or naturally scented.

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    3. I have used California Baby conditioner in the past. I can't remember much about it - so it must have been just okay. Granted, at the time my hair was waist-long and sun-and-pool damaged. Stonybrook Conditioner (unscented) is lighter-weight and has dimethicone. So it might get heavy with repeated use if your hair is easily weighed down. Rainbow Research Conditioner for Kids is cationic-free, comes in unscented and works fairly well unless you have lots of tangles. Earth Science Citress Conditioner is great if your hair is okay with wheat protein. Giovanni Direct Leave-in and Giovanni Magnetic Restruxuring Conditioner should not be especially heavy - I'm not sure about these particualr Giovanni fragrances. Magick Botanicals Conditioner isn't overly heavy and is unscented.
      I used to love Aussie Aussome volume conditioner or Aussie Moist conditioner. The formula has changed a bit since I used them, but they're okay in moderation.
      You can dilute conditioners with water (when you use it) also - to make it less heavy and build-up-provoking. Sometimes just a little conditioner and a lot of water is just right!

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    4. I referenced yiur blog in a post on the Curltalk forums to help other ladies in need who cant figure out whats wrong with their hair. The forums wouldnt let me paste a link but i did mention the blog. Hope you dont mind.

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    5. Hello again, Stormchaser. I don't mind at all. That was very thoughtful of you. Thanks.

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  5. Great article!! Very informative and I didn't find it long-winded at all! LOL!

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  6. This is such helpful information. I'm literally over here taking notes. Which is also how I came up with this info and decided to comment: Ouidad Superfruit Clarifying Shampoo has Sodium C14-16 Olefin Sulfonate as its 2nd ingredient, and Sodium Polystyrene Sulfonate as its 23rd. I'm thinking that having these detergents may be helpful in removing cationic polymers, and could possibly be added to your list on the post. That being said, there are a LOT of other ingredients in it (~30 total), so there may be others that aren't as good. In fact, there are two Polyquats (7, 10) that are further down on the ingredient list.

    Oh darn, I'd started this reply to be helpful, but now I have a question. Would you happen to know about this product? Can polyquats in a shampoo be cleansed by surfactants in the same product? Thank you!

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    1. I do need to add that product! Thank you. I don't know for certain whether polyquats can be removed by surfactants in the same product, but it seems unlikely. I do know that silicones, including those that bond to hair (like polyquats do) will be deposited on hair in a shampoo formula. So while there is removal of build-up, there is also deposition. But if you think about concentration - the net effect might still be "clarifying." You have a build-up removing surfactant that should be removing residue in your hair that were present in styling products, there may be enough accumulation there that more is removed than deposited.
      It's okay for sodium polystyrene sulfonate to be low on the ingredient list, it's effective below 1% concentration. In using Polyquaternium-7 and 10 for lubricating in the shampoo, it retains a lubricating feel so you have a good experience in a clarifying shampoo and hair doesn't tangle or feel dehydrated or straw-like. So that's a calculated and smart move. I would much rather not have a tangly, matted mess to deal with when I want to get the gunk out of my hair by clarifying. And if clarifying makes hair feel good and doesn't dehydrate - then it can be done often enough to keep ahead of build-up.

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  7. Thank you very much for this article and the Silicone Solubility ingredient article. I was absolutely driving myself crazy between silicone/silicone free products.
    It appears silicones, including Dimethicone can much more easily be removed than cationic surfactants. All I would have to use is a silicone-free shampoo.

    I'm glad that I didn't make the switch to silicone-free cationic products. I have fine, dry, curly hair that I blow out straight. My hair tangles easily as the ends curl thought out the day. It seems silicone products old be best for my hair after all.

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  8. Do you think Live Clean Apple Cider Vinegar Clarifying Shampoo can remove product build-up?

    Ingredients (in this order): a bunch of herbal extracts, vinegar, sodium methyl 2-sulfolaurate, disodium 2-sulfolaurate, sodium lauryl sulfoacetate, cocomidopropyl betaine, glyceryl stearate, tocopheryl acetate, glycerin, panthenol, parfum, polyquaternium-10, citric acid and preservatives

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    1. Hello Elus,
      I don't think the detergents in this product would be particularly outstanding at removing product build-up, but it should help remove excess oils.
      For the vinegar - we don't know the concentration of acetic acid in the product. Vinegar is not widely regarded as being good for removing product residue. Vinegar and water rinses can help with mineral residue from hard water and sometimes it promotes shine - which might mean it has removed something that was dulling to the hair. But with this product, it's difficult to know what effect the vinegar will have.

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    2. What about this one? It is the Neutrogena T-Gel for sensitive scalp. Would this be too drying for occasional use?

      Aqua, Sodium C14-16 Olefin Sulfonate, Cocamidopropyl Betaine, Salicylic Acid, Sodium Chloride, Linoleamidopropyl PG-Dimonium Chloride Phosphate , Propylene Glycol, Hexylene Glycol, Cocamidopropylamine Oxide, Polyquaternium-22, Sodium Sulfate, Disodium EDTA, Sodium Citrate, Tocopheryl Acetate, Phenoxyethanol, Ethylparaben, Methylparaben, Propylparaben

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    3. Hi Elus, These look like the ingredients for T-Sal with salicylic acid rather than T-Gel. T-Sal would be excellent for removing product residue, Sodium C14-16 Olefin Sulfonate does a good job of that. I use this shampoo sometimes and I think it should be fine for occasional use. If your hair feels too lightweight - follow it with a good conditioner left on for a little longer than usual, and maybe a bit of oil on the ends if your hair is long.

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