What Role Does Propylene Glycol Have in Skin Care and Beauty Products?

Is it safe?

Depending on where you search, you might find alarming language in relation to propylene glycol, including words like “toxic” and “carcinogenic.” There’s some reasoning behind this language: Propylene glycol is often derived from petroleum. But Joshua Zeichner, a board certified dermatologist and an associate professor at the Mount Sinai Hospital in NYC, explains that since cosmetic-grade petrolatum (petroleum) isn’t the same as commercial petroleum. So, this isn’t a reason for concern. Purvisha Patel, a board certified dermatologist, agrees. She explains that people likely think it’s unsafe, because it’s formed by adding water to petrolatum, but both of these ingredients are safe. Patel says propylene glycol is inert, or chemically inactive, and there’s no reason to avoid it in your beauty and skin care products. The Environmental Working Group gives propylene glycol a “fair” rating and notes that it poses no risk of cancer or developmental and reproductive toxicity. But it does acknowledge an association with irritation and contact dermatitis, even in concentrations as low as 2 percent. Chemical, food, and pharmaceutical industries commonly use propylene glycol as an additive. According to the ATSDR, it’s included in:

• coolants
• antifreeze
• plasticizers
• heat transfer and hydraulic fluids
• smoke screens and simulators

Given these uses, it makes sense that you might worry when you see the same ingredient in your favorite lotion. “But the reality is that many products contain propylene glycol, and they are safe to use for the general population,” Zeichner says.

Benefits of propylene glycol

Propylene glycol is an ingredient in many lotions, soaps, shampoos, conditioners, shaving creams, deodorants, and more. What makes it such a popular ingredient? Here are a few key reasons.

It’s a preservative

Propylene glycol can help lengthen the shelf life of skin care products thanks to antimicrobial properties that help prevent the overgrowth of microorganisms. This helps preserve the products.

It’s a humectant

“At low levels, propylene glycol is often used to improve moisturizing benefits of a skin care product, as it has a high affinity for water,” Zeichner says. Humectants pull water into the skin and help keep it there for more supple, hydrated skin. That’s why propylene glycol is often used in moisturizing formulations.

It makes other ingredients more effective

Active ingredients can better penetrate the skin, thanks to propylene glycol. To put it another way, your favorite serum may work well because of the benefits of this additive.

Potential side effects

While propylene glycol is pretty common, the ingredient won’t work well for everyone. “The problem with propylene glycol is that it not uncommonly causes allergic reactions in the skin, known as contact dermatitis,” Zeichner explains. You could potentially develop a rash when using a product with propylene glycol if you:

• have skin conditions, like eczema
• have a history of allergies
• have sensitive skin

According to Zeichner, this is the main reason why propylene glycol has developed a negative reputation. Patel notes that dermatologists can test for sensitivities or allergies to propylene glycol. If you’re concerned you might have a reaction to this ingredient, or if you’ve noticed a rash or other reaction after using a product containing propylene glycol, it’s a good idea to connect with a dermatologist. Some skin care products can cause unwanted reactions. It’s always best to stop using a new product and check with a dermatologist if you notice:

• inflammation, swelling, bumps, or hives
• skin discoloration
• itching or stinging
• bumpsor hives

Patch testing when you try a product for the first time can help you determine if your skin will tolerate the product. To patch test:

1. Apply a small amount of the product to an area of skin near where you’ll be using the product. You might, for example, test a body lotion on your inner elbow, and a facial moisturizer behind your ear or along your jaw.
2. Wait at least 24 hours.
3. Check the area for any changes, like swelling, itching, or irritation.
4. If you don’t notice a reaction, you can go ahead and use the product.