What is Propylene Glycol?

Propylene glycol (PG) is a colorless, nearly odorless, syrupy liquid that is derived from natural gas. It is used in dozens of products that you commonly use around your house.

Propylene Glycol is used in food – Cake mixes, salad dressings, soft drinks, popcorn, food colorings, fat-free ice cream and sour cream. It also protects food from freezing and helps as a preservative, in toiletries and cosmetics, shampoos, antiperspirants, lipstick, lubricants
In other household items such as room deodorizers, cleaners.
And specific to the soap making and toiletry making industry, it is also used as a carrier in fragrance oils and in many melt and pours soap bases.

Since e cigarettes emerged as a substitute, PG is used in solutions we find in e cigarette cartridges. It is “to blame” for the vapor we see when inhaling or vaping.

Over the past few years, there has been a lot of controversy about propylene glycol. It is generally recognized as safe (GRAS) by the U.S. Food and Drug Administration (FDA) in 21 CFR § 184.1666, for use as a direct food additive under the conditions prescribed. It is approved by the U.S. FDA for certain indirect food additive uses.

It is up to each manufacturer of personal care products, and consumer of the same, to make up their own mind. If you are using fragrance oil, melt and pour soap base, or pre-made liquid soap or shower gel, chances are, there is propylene glycol in it. You need to understand the ingredients in your products and make an educated choice.

PG is not acutely toxic (single dose, high exposure). It is essentially non-irritating to the skin and mildly irritating to the eyes. Numerous studies support that PG is not a skin sensitizer or a carcinogen.
Inhalation of the PG vapors appears to present no significant hazard in ordinary applications.

PG is not volatile, and is miscible with water. Concentrations of PG in the air are expected to be extremely low because of its low vapor pressure. It is readily biodegraded in water or soil (via aerobic and anaerobic mechanisms).

So, like I said, chances are you’ve been using products containing propylene glycol for years.