Mystery Meat: Deciphering Cosmetic Ingredients

Hi, Amy! First of all, you are amazing! You’re funny and interesting and helpful. So thank you for that. Now to my question.
I’ve been looking at reviews for hair products (namely conditioner) and some stuff gets great reviews. “Amazing for my wavy hair!” I have wavy hair! I want amazing! But then I look at the ingredient list (I am weird) and see all sorts of things that I think maybe don’t go in my hair. Several alcohols (cetyl and some others), propane, and crazy chemicals. I know alcohol shouldn’t be going on my hair or skin, but it seems like all the stuff I’m looking at has it. And propane? That’s for camping stoves, not hair. Amy, how do I know what’s ok for my hair and what’s not? I know you recommend certain products, but I want to be able to look at other things and know if they’re ok to use or not. Because I am not using my hair to start a fire. Please help me. Thank you!!!
–Elissa
Ah, the dreaded ingredient list. There’s a reason some cosmetic brands make them so hard to find. It’s always amusing to me (now I am weird) to pick up stuff that’s aggressively marketed as “natural” and “pure” and take a look at the ingredients. Oh look! Acids, alcohol, brutoniumsulfateacium 70. And then a little aloe vera and fruit oil, all the way down on the last line.
That said, I am not a chemist and in fact, barely freaking passed chemistry in high school. I don’t know everything about every ingredient. I do know my own personal deal-breakers (fragrance, animal by-products, ethyl alcohol), and I know other people have a much longer list of stuff they’d like to avoid (parabens, sulfates, petroleum derivatives, and so on). For me, as long as I am not eating it, I’m okay with a few mystery chemical ingredients. (Provided that the product, you know, WORKS.)
Since I’m so far out of my area of expertise (how to make your crappy skin 27.4834% less crappy!), I’m going to keep this pretty specific to just your question. First, there IS a world of difference between the alcohols commonly found in beauty products and the kind of alcohols you’re probably thinking of. These aren’t rubbing alcohols or anything harsh like that.
Cetyl, cetearyl and stearyl alcohols actually come naturally occurring fatty acids in fruits and vegetables. They’re emollients, usually derived from coconut oil. They are used to thicken up products and soften your hair and skin. They are nothing to be afraid of. Unless you’re allergic to coconut, maybe, and I just made that specious bit of logic up right now. I have no idea if an allergy to coconut would translate.
As for propane, I’ve never seen that listed on a bottle of conditioner, but it is used as a propellant in spray-bottle-type styling products. And as far as propellants go, it’s not a bad choice. (Remember aerosol sprays and the Aqua-Net-shaped hole in our ozone layer?) Propane is natural and non-toxic.
(Actual pure propane should not be confused with something called 2-Bromo-2-nitropropane-1, 3-diol, which some cursory web searching flags as a possible-to-likely carcinogen. It’s sometimes listed as BNPD on shampoos and moisturizers and sunscreens.)
(And yes, I just ran upstairs to check every bottle of everything I own, and no, I didn’t see it.)
That leads to my final bit of advice: if you don’t know what something is, plug it into Google and look it up. There are a ton of great ingredient “dictionaries” out there to help you decipher the gobbledygook. I like this one, since it pulls definitions from a variety of sources so you can see if a definition fits the general consensus or if there’s some bias one way or the other. (brutoniumsulfateacium 70: perfectly safe! delicious on sundaes! vs. brutoniumsulfateacium 70: OMFG RUN YOU ARE GOING TO DIE.)
In most cases, like the alcohols, you’re probably going to find yourself relatively comforted. Cosmetic companies really don’t want to kill you. Or your hair. They actually want you to like their products and buy them again and recommend them to your friends. Of course, mistakes get made and dangers are often learned later, and then it’s up to the consumer to be aware and educated in case the companies drag their feet on reformulating. (And again, remember there’s an AWFUL lot of bias and fear-mongering out there, so don’t take the first Google result’s word for it. Do your own research. The more you know! Knowledge is power!)