One such example is propylene glycol. It used to be that the petrochemical-derived ingredient was to be avoided in the clean beauty and natural food space (it’s a common food additive as well as being a skin care ingredient). However, if you are one to read ingredient lists and only shop clean skin care retailers, you’ve likely noticed it showing up in some products recently. So here’s everything you need to know about it—including how to identify bio-based options. However, researchers discovered that they could make the molecule out of botanicals, like vegetable oils, corn, and sugar cane. “There are two kinds of propylene glycol: alpha and beta. The beta version, also known as propanediol, is available from fermentation of cornstarch, without any petrochemicals,” she says. “Vegetable-based propylene glycol is definitely the right choice. It has all the great properties of its petroleum-derived cousin, as well as preservative-boosting capabilities that are great in any formulation.” Some producers go a step further and ensure it’s GMO-free. While it’s a relatively new innovation, several green cosmetic labs have begun producing it en masse. Ideally, as consumer demand grows, so will production. That’s the thing about green cosmetics: The technology is evolving rapidly; the consumer just needs to push brands to utilize it. Propylene glycol and ethylene glycol are often confused with each other but are, in fact, structurally different ingredients. Bio-based propylene glycol is safe, not considered a carcinogen or endocrine disrupter, and what you’ll find in clean skin care products. Ethylene glycol is a known carcinogen, endocrine disrupter, allergen, toxin, and is what’s actually in antifreeze. Often people confuse glycols in general (for example, polyethylene glycol, or PEG, is another common “no” list ingredient). “Sometimes consumers mistakenly believe that all glycols are the same—but this is not the case,” board-certified dermatologist Loretta Ciraldo, M.D., FAAD, previously told us about glycols. This is completely understandable—the average shopper shouldn’t be expected to be a chemist after all. This is why we always recommend using clean retailers and websites to help you decipher these nuances. Additionally as we noted above: Some report finding the ingredient irritating—and some have allergic reactions to it. This is, however, much more common for face products than when used in personal care—like in deodorants. We always advise doing patch tests prior to starting any new product.
