Today’s question, submitted via the FutureDerm.com Facebook page:
Can you share your thoughts on the use of propylene glycol in skin care? Is it dangerous like some sites would like us to believe because it’s the same ingredients used in anti-freeze? From what I’ve learned, it’s anti-freeze made with Ethylene glycol that’s deadly. The other concern is it’s a skin irritant, but is approved for use in concentrations up to 50%. Any light you can shed would be appreciated.
In a word, no. Propylene glycol is not harmful in beauty products.
The internet rumor started about five years ago, when people realized the Material Safety Data Sheet (MSDS) can cause liver and kidney damage and act as a skin irritant. Considering that over 4000 beauty products in the U.S. alone contain propylene glycol, this was a big deal, to say the least. However, MSDS sheets refer to 100% concentrations of a substance, as propylene glycol is found as anti-freeze. In the small concentrations used in skin care cosmetics, it is not a concern. According to the U.S. Department of Health and Human Services, propylene glycol is classified as GRAS (Generally Recognized As Safe), and proclaims, “studies have not shown these chemicals [propylene or the other glycols as used in cosmetics] to be carcinogens”.
What about the Cosmetics Database warnings?
The Cosmetics Database finds propylene glycol to be a moderate hazard ingredient and has concerns regarding cancer, developmental and reproductive toxicity, allergies and immunotoxicity, irritation and enhanced skin absorption, and organ system toxicity. Lesser concerns include neurotoxicity and endocrine disruption.
However, after careful review of these studies, it becomes evident that these studies also focused on propylene glycol in 100% concentration, not in the minute concentrations it is used in cosmetics. Propylene glycol does not accumulate in the system either. The majority of these studies were also performed on rats, and some of the amounts of propylene glycol used were not adjusted to be proportionate to the size of the rat.
Keep in mind the Cosmetics Database and similar sites compile lists of studies as potential warnings for consumers. You must become an informed and educated consumer to differentiate between potential and absolute warnings, or you could actually be doing yourself more harm than good in the long run! For instance, a 2010 widespread report declared sunscreens with retinyl palmitate were dangerous and could cause skin cancer. However, the American Academy of Dermatology published a 2011 review notifying the report was erroneous (full story). Yet imagine all of the people who stopped using sunscreen, putting themselves at true risk for skin cancer!
So is there any risk with propylene glycol?
There is only one minor concern: Propylene glycol may make your skin more susceptible to irritation when used with irritating skin care ingredients. Propylene glycol enhances the penetration of other ingredients into the skin as an absorption enhancer. This is why propylene glycol is used in transdermal patches. To learn more about potentially irritating skin care ingredients, visit Temptalia for the most comprehensive list I’ve seen yet!
Avoid using propylene glycol in conjunction with potentially irritating ingredients, but rest assured propylene glycol is a safe ingredient in the concentrations it is found in skin care and cosmetics.