Wednesday, April 1, 2009
Weird Product Wednesday: Propylene Glycol
If you counted all the times I've had my head up my butt about ingredients, you'd get a number higher than the Nasdaq. (True that number is lower than it has been, but it's still pretty high.)
Take propylene glycol, for instance. About a year ago, after reading CurlChemist's article on Humidity, Humectants, and Hair, I took a gander at her list of humectants at the bottom of the page. In my addled little pea brain, I noticed that many of the humectants contained gly in their names and so I made the rather natural assumption that the gly meant they were derived from glycerine, the mother of humectants.
[Buzzer sounds] I was wrong.
Turns out that propylene glycol is a petroleum product. No reason for concern, says CurlChemist, and I have to agree, even though I try to avoid petroleum products whenever I can. (Like, I once had a friend who slept with Vaseline on her face every night. She had great skin but I just couldn't bring myself to emulate that particular ritual without evoking images of oil derricks and highly flammable job sites.) Although it is a humectant and works very much like glycerine, propylene glycol does not contain glycerine.
But get this. Scientists are at work to convert glycerine into propylene glycol! Seems it's a renewable (read: eco-friendly) method of propylene glycol production. (Yes, propylene glycol is used in anti-freeze, but that's not as scary as it sounds. The more you learn about ingredients, the more you realize that our laundry detergent contains the sulfates that are in shampoo, our hair conditioners contain the very compounds that make fabric softeners work so well, and that personal care products benefit from the same viscosity that anti-freeze does. What a world, huh?) I haven't found too much more about this topic that's recent, but I thought it was interesting that the gly in propylene glycol may not signify glycerine now, but it will in the near future!
I do avoid propylene glycol because my hair is not a big fan of humectants, but at least now I know not to avoid them because they are glycerine. Yet.