Monday, February 6, 2012

Surfactants - what are they?

Quite a few people have written to tell me lately that they are avoiding surfactants in their products. The problem is this - Surfactants aren't just about the foamy lathery things you find in body washes and conditioners. They are found in things we eat, things we use on our hair and bodies, and even in our lungs! If you eat salad dressing or mayonnaise, enjoy lotions or creams, wash your dishes or clothes, or condition your hair, you're using a surfactant! Let's take a moment to learn a little more about surfactants!

WHAT ARE SURFACTANTS? (Original post from April 4, 2010)
First, a definition (from Wikipedia): Surfactants are wetting agents that lower the surface tension of a liquid, allowing easier spreading, and lower the interfacial tension between two liquids. (In other words, a surfactant makes it possible to mix oil and water or for lathery things to remove oil or dirt from your skin or clothes.)

Surfactants have a hydrophilic (or water-loving) head and a lipophilic (or fat-loving) tail. The hydrophilic head clings onto watery stuff - say the water phase of our lotion - and the lipophilic tail creates a ball around the oily stuff - the oil phase of our lotion 

Surfactants come in four flavours (as it were...)
  • Anionic - negatively charged
  • Cationic - positively charged
  • Non-ionic - neturally charged
  • Amphoteric - both positive and neutral
Click here for Fun with Chemistry: Anionic, cationic, and non-ionic! 

These charges are important; they define what kind of emulsifier we need for a specific product. Surfactants can be things like emulsifiers (which are generally non-ionic), conditioning agents (like BTMS or cetrimonium bromide, which are cationic), foamy and lathery things (which are generally anionic, sometimes non-ionic, possibly amphoteric).

Polawax and emulsifying wax are non-ionic surfactants. When we combine something like glycol distearate and ceteareth-20 (low and high HLB emulsifiers), we get a non-ionic surfactant.

Incroquat BTMS-50, Incroquat BTMS-25, Incroquat CR, cetrimonium bromide, and cetrimonium chloride are cationic or positively charged surfactants.

Our lathery surfactants like SLeS, SLSA, SCI, SMO or SMC taurate, or C14-16 olefin sulfonate are anionic surfactantsClick here for more information on anionic surfactants (the lathery, foamy, bubbly ones!)

Cocamidopropyl betaine or disodium cocoamphodiacetate are considered to be amphoteric surfactants. 

All right! So know that you know how to identify surfactants, let's take a look at this question!

Anonymous asked in this postThanks for the info. I am learning a lot. Could you tell me whether or not this product has any surfactants and the best way to recognize them in a product?

I really encourage you to learn the INCI names of our ingredients! It makes life so much easier when you're looking at ingredient lists. I really can't stress this enough. Most of the questions I've been posed in the last week or so have been answered by knowing the INCI names of the ingredients we can buy!

Related posts:
What's an INCI name and why should I care? 
Reading INCI names

The other thing that keeps coming up is people trying to avoid surfactants. I know I'm being pedantic here, but you can't avoid surfactants as they're everywhere. What I think those people mean is that they are trying to avoid anionic or bubbling, lathering, foaming surfactants. For that information, please visit the surfactants section of the blog (the chart is very useful!) because I won't be answering any questions on how to identify those after this post as I simply don't have the time and you have the resources available to answer it yourself! I'm teaching you to fish! 

If this is a conditioner, consider the type of surfactants you should find in this kind of product. A conditioner will contain positively charged or cationic ingredients. What are the most common positively charged or cationic ingredients? Incroquat BTMS-50 and Incroquat CR. Take a look to your right - there's a list of ingredients there. Please click on them to see what the INCI name is for each product. Go ahead...I can wait...

Welcome back! Look at this list and look for the cationic surfactant! You should see it immediately!

The product is Natty Moist Conditioner and the ingredients are:
Water (Aqua) infused with Equisetum Maximum Lam (Horsetail), Mentha Piperita (Peppermint), Rosmarinus Officinalis (Rosemary), Laurus Nobilis (Bay Leaf), Ocimum Basilicum (Basil), Arctium Lappa (Burdock Root), Althaea Officinalis (Marshmallow Root), Origanum Vulgare (Oregano), Cymbopogon Flexuosus (Lemongrass), Thymus Vulgaris (Thyme), Salvia Officinalis (Sage) and Urtica Dioica (Nettle); Behentrimonium Methosulfate (and) Cetearyl Alcohol, Aloe Barbadensis Leaf Juice, Butyrospermum Parkii (Shea Butter), Persea Gratissima (Avocado) Oil, Theobroma Cacao (Cocoa) Seed Butter, Soy Lecithin, Diazolidinyl Urea (and) Iodopropynyl Butylcarbamate

If you read the ingredient posts, then you can see that the cationic surfactant in the mix is behentrimonium methosulfate. If you read the post on INCI names, you'll know that this company is using Incroquat BTMS-25 - INCI: BTMS-25 is behentrimonium methosulfate (and) cetearyl alcohol.

As an aside, you could duplicate this product quite easily! All those extracts are probably used at 0.1% to 1% but the company is listing them as infused into the product to make it seem like they make up a goodly portion of the conditioner (they don't). The first real ingredient is the BTMS-25, which you'd use at 1% to 7% or so, and everything below that is used at lower levels than you used the emulsifier - probably 2% to 5% each. Check out the hair care section for some starter recipes you could try!

The writer goes on to ask about another product: Also, could you tell me whether this USDA Certified product contains any sulphates -whether strong or mild- because this is what I use to cleanse my hair.
Terressentials Mud Wash - Ingredients: Organic aloe vera juice°, clay minerals, organic extracts° of organic linden flower°, organic nettle°, organic chamomile°, organic shavegrass° and organic vanilla°, essential oils of organic sweet orange°, organic patchouli°, organic true lavender°, organic petitgrain°, organic atlas cedar°, organic cinnamon leaf° and organic pine needle°.

I'm not really sure why you'd avoid sulphates as they come in all kinds of different forms and only SLS is considered to be a non-mild surfactant. How do you identify a sulphate? Click here for the post on this topic. And visit the surfactants section of the blog for more information on the negatively charged or anionic surfactants that make up the lathery, bubbly, and foamy category of surfactants!

Related posts:
Surfactants section of the blog
Hair care section of the blog
Ingredients section of the blog (look to your right!) 

6 comments:

Lise M Andersen said...

Great post Susan. :)

Ben said...

Excellent, Excellent post.

You mentioned that Polawax and HLB emulsifiers are non-ionic. Does this mean that Polawax has the same properties as HLB?

I've been mulling over what kind of emulsifiers to use for various products. I want to try them all and just compare, but I haven't the time nor the money to do that! (Although I do have the curiosity to do it!)

I guess my question is: can you provide a side-by-side comparison of the popular emulsifiers: BTMS-50, BTMS-25, HLB, Polawax, and others -- and put them in a downloadable PDF like only you can do? (Y-axis = Emulsifier; X-axis = common usage, chemical charge, qualities for hair, qualities for skin, recommended use %, other)

And I love how you have the 25% rule for Polawax. Hasn't failed me yet. Is there a similar rule for BTMS? Does BTMS have a limit for amount of oils it will emulsify?

Ben said...

also...I remember reading somewhere, whether it was on this particular post or not, that with BTMS, we don't get the conditioning aspects of it until we rinse it out. Can you explain this a bit further? And does it have any other qualities besides conditioning (can we condition our SKIN?)

Susan Barclay-Nichols said...

Hi Lise! Thanks!

Hi Ben! Yes, Polawax is considered to be an HLB type emulsifier with - we think, but can't confirm - a low HLB and high HLB emulsifier in it. As for the chart - I can do some posts on the various emulsifiers, but I don't think I'm a graphing kind of girl. (Okay, I'm taking a math class heavy on the graphing right now, but it's not my forte!) I can only reflect on the emulsifiers I've used and my experiences with them.

The Polawax rule isn't mind - they note it in the literature - and there isn't a rule for any other emulsifiers. I do the 25% rule with every new emulsifier I meet, and it hasn't let me down so far. I realize I'm wasting emulsifier - some people would say - but if the product works, then I think it's worth it!

As for conditioning the skin, you can actually condition skin with cationic ingredients (and things like proteins). It means that the ingredients adsorb to your skin to leave behind a film that leaves the skin moisturized without necessarily using oils and butters!

I don't remember saying that you don't get the conditioning qualities until you rinse it off...I'm wondering if you're referring to the idea that leaving your conditioner on for more than two minutes is a waste of time because it doesn't get more conditioned after about two minutes? And only the spots where the conditioner touches actually get conditioned? I remember writing those things! But those have to do with hair, not skin!

Ben said...

I didn't mean to infer that you create a graph. X-axis simply refers to the categories on the top from left to right, much like the A, B, C, D of an excel spreadsheet. The Y-axis refers to the rows of categories on the left that go top to bottom, much like the 1, 2, 3, 4 of an excel spreadsheet. You've created many of these charts for things like butters and exotic oils, but not for emulsifiers. I ask because you have more experience and knowledge of more emulsifiers than I do, so anything would help (although my BTMS is on the way, so I'm catching up!)

I can't find the post where I read the comment about needing water to get the conditioning aspects of the BTMS, either. I'll keep looking, maybe I misread something.

Anonymous said...

Thanks for the post and for explaining the infusing part of the supposedly Natty Moist product. After reading the ingredients, whoever posed the ingredients for Natty Moist actually put the ingredient list for Jessicurl Deep Conditioner. The ingredients for Natty Moist are Ayurvedic Herb Infused Distilled Water, Unrefined Shea Butter, Avocado Butter, Cupuacu Butter, Extra Virgin Olive Oil, Aloe Vera Extract, Guar Conditioner, BTMS, Cetearyl Alcohol, Panthenol (Pro Vitamin B), Citric Acid, Vegetable Emulsifier, Vitamin E Oil, Essential Oil Blend, Potassium Sorbate, Natural Fragrance.
And NO I am not asking you to define any ingredients, I have already determined each one myself.