If you're reading labels (and I hope you are!), you've probably seen “propylene glycol” on your skin care and hair care products—hopefully those you're not using anymore! Here's what this ingredient is and why it's best to avoid putting it on your body.
A Few Crude Oil By-Products, Anyone?
Propylene glycol (PG) is used in liquid foundation, spray deodorants, moisturizers, lipsticks, suntan lotions, shampoos and conditioners, baby wipes, and more. Strangely enough, you'll also find it in your antifreeze, brake and hydraulic fluid, floor wax, and paints.
PG comes from propylene, which is a chemical produced as a side effect of petroleum refining. Yes, I'm talking about real petroleum, or crude oil obtained through oil drilling. It can also be manufactured from natural gas.
From propylene, chemists can create a variety of products, including polypropylene (used in plastics), and propylene oxide, from which we get propylene glycol. PG can mix with water and is considered non-toxic, so companies use it in a variety of ways:
- As a solvent, which helps one ingredient dissolve into another, producing a solution
- As a stabilizer, helping to keep products constant at various temperatures
- As an emulsifier, which helps mix together a variety of ingredients
- As a humectant, helping formulations to attract and hold onto moisture
Because it can do so many things—and because it's economical—propylene glycol is used across several industries, and may show up in your processed foods and beverages, makeup, liquid and spray medications, and pet food. This isn't necessarily bad, but it does raise some questions, like: Is this stuff really something I should be using on my skin?
Contributes to Dry Skin Over Time
Like mineral oil, which I wrote about in an earlier post, PG forms a sort of seal over your skin, preventing the escape of water. (Note that it doesn't add any moisture to your skin.) Meanwhile, it attracts and draws moisture from the lower layers into the top layer, helping your skin appear smooth and soft. Great for a short time, but as you use more and more, those lower layers gradually dry out. Your skin appears dull, exacerbating the look of any fine lines or wrinkles.
PG also tends to sit on the surface of skin after you rinse it, dissolving the fats and oils your skin needs to stay nourished. Your skin reacts by becoming parched and dry and requiring more applications of moisturizer, which make skin dryer, requiring more moisture. It's a vicious cycle.
What's Getting Into Your Bloodstream?
PG also enhances penetration. That means the cream or lotion you're using is more likely to penetrate the surface layer of the skin and go deeper, sometimes into the bloodstream. So far we have no scientific studies on the long-term effects of our exposure to this chemical, but we do know that other similar chemicals—like bisphenol-A (BPA) and triclosan—have been found by the Centers for Disease Control and Prevention (CDC) to accumulate in the human body.
One more thing: According to the Material Safety Data Sheet on propylene glycol, the chemical is a strong skin irritant, and has been implicated in contact dermatitis. The sheet goes on to warn that the ingredient can inhibit skin cell growth and damage cell membranes, causing rashes, dry skin, and surface damage.
Does this sound like something to help improve the health and appearance of your skin?
It's easy to avoid this ingredient. Just look for it on the label. Better yet, buy from reputable, organic skin care brands that are more conscientious and selective in the ingredients they use in their formulations. Give your skin real nourishing, moisturizing ingredients and I think you'll notice the difference right away!