Sunday, September 14, 2008
The low-down on emollients
Sometimes I write like I know everything. But I don't.
So, the issue I raised a couple of months ago about "empty conditioners" nagged at me. If there were people who loved conditioners that were exclusively emollient-based, and had great results from them, could they be all bad? Maybe I had vilified those products unjustly. Seeking a good, scientific answer, I went to Tonya McKay, MS polymer and colloid chemist, who writes the Curl Chemist column at naturallycurly.com. Knowing she's got her hands full with a new baby, I tried to keep my questions to a minimum. She graciously answered them! Here is that interview. (And by the way, that photo is not a picture of Tonya.)
Lorraine Massey defines as good conditioner as one that contains oils, humectants, emollients, and proteins. Obviously, different conditioners have different proportions of these ingredients, and I've also noticed that some conditioners contain only one or two of them. Typically, humectants and emollients comprise many of the conditioners I see lately, and I'm thinking that that's almost like "fooling" hair into thinking it's gotten some benefit! You've written some excellent articles on humectants and I see their value, but I'm not as clear on emollients.
Jillipoo: I had always considered emollients to be the chemicals that allow other ingredients to work together and blend more easily. I also think of them as "fillers" and "smoothers," but Wikipedia says that an emollient has three components: occlusion, humectant, and lubrication. Can you define what an emollient really is, in hair product terms?
Tonya: I think you may be confusing emulsifiers with emollients, when you think of the ingredients that help other ingredients work together and blend well with one another. An emollient is the main conditioning agent (or agents) in a product. The term emollient is really more appropriate for discussion of skin care products, and the term moisturizer or conditioning agent for hair care products, but you will see them both used in the literature.
An emollient forms a protective film over the surface of hair or skin, which adds gloss and shine to the hair, protects the hair from water loss to the environment (occlusion), and helps the hairs slide easily against one another which facilitates detangling and prevents breakage and damage from tangle, and can act as humectants (but not always).
Examples of emollients would be dimethicone, Polyquaternium-10, dimethicone copolyol, amodimethicone, shea butter, jojoba oil, Cetearyl alcohols, many proteins, coconut oil, mineral oil, petrolatum, alkyl esters, etc.
Jillipoo: Can a conditioner that is entirely emollients (or emollients and humectants) truly condition the hair?
Tonya: I guess I am not sure what is meant by this question, since by definition, emollients are conditioning agents. If you wish to know if externally applied products can truly have any lasting benefit to the hair other than cosmetic enhancement and prevention of further damage, then my opinion is no. The role of conditioning agents and humectants and proteins are all to fill in the gaps where structural damage has occurred, to bring moisture into the hair or keep it in the hair, and to provide lubrication between hairs which leads to less mechanical damage from friction between hairs. Thus, they make the hair more attractive, feel softer to the fingers, and incur less damage. As it is protected by daily use, new hair can grow in and remain healthy and undamaged, so in that sense these products have true benefit.
Jillipoo: Are there some emollients that can actually have detrimental effects on hair?
Tonya: Certainly! Silicone is an emollient. Some feel that build up from the use of silicone can lead to dry, brittle hair eventually that gets damaged more easily. Also, some oils used as emollients can actually increase thermal damage to the hair if a person applies them and also uses heat styling techniques (hair dryers, hot rollers, curling irons, flat irons, etc.). Other emollients, such as fatty alcohols have been known to attract dirt to the hair, making the hair lose its luster and feel greasy.
So ... I am still not inclined to go with an emollient-only conditioner, but at least know we've all got a better perspective on what emollients are and what to expect from them!