eLiquid-ology: What is Propylene Glycol?


Propylene Glycol & What It Has To Do With Your eLiquid

Chemically, propylene glycol is a colorless and clear form of mineral oil that is liquid at room temperature. It does exist in vapor form, but it either has to be forcefully shaken or heated in order to sublimate it into vapor.  It's produced by the fermentation of yeast and carbohydrates of propylene oxide, because of this when it is used in foods PG is considered a carbohydrate.

Quick facts on Propylene Glycol

  • In the terms of common chemicals used by consumers, propylene glycol has had an incomparable reputation for safe use in products like cosmetics, pharmaceuticals, numerous food products, and in its other form it is also used industrially.

  • It is used as a stabilizer, meaning that because of its chemical stability it is used to chemically bond things together, or keep liquids from evaporating and it is also great at keeping foods moist. It is used in a lot of products that we eat everyday as the Food and Drug Administration (FDA) has deemed it safe for human consumption.  

Characteristics of Propylene Glycol

  • Emulsifier for two ingredients that normally would not mix well together. PG creates a stable homogeneous fluid that holds the two products together (like shampoo or moisturizer for your face)

  • Chemically, it binds and transports other substances (good for transporting medication through a person’s body)

  • Holds and dissolves other chemicals

  • Attracts and holds water (used commonly as a humectant for curly hair)

  • Decreases freezing point

  • Increases boiling point

  • Serves as a diluent

  • Stable when exposed to extreme conditions (high flash and boiling points) 

Safety of Propylene Glycol

PG is on the generally recognized as safe (GRAS) list as rated by the Food and Drug Administration and the World Health Organization feels the same way. These results also satisfied the Cosmetic Ingredient Review Expert Panel, which led them to conclude that there was no carcinogenic risk with low levels of PG ingestion. 

Pharmaceutical Grade PG & Its Uses (Other than e-liquid)


Personal Care Products

•Bath & Shower Soaps

•Gels, shaving foam, after shave



•Fragrances & Perfumes


Skin Care Products

•Face wash

•Hand, body, & facial moisturizers

•Sunscreen products


Hair Care Products



•Styling gels




Oral Care & Baby Care Products






Food Additive

•Solvent & Carrier of flavor in food and drink manufacturing

•Artificially flavored drinks, cookies, cakes, & candy

•Stabilizer, thickener, & clarifier

•Beer, salad dressing, baking products


Cattle and Pet Feed Additive

•Used as a humectant (to hold moisture)

•Stabilizer and preservative

•Also used for increased energy supply

•Not used for cat food


Pharmaceutical Use


•Vitamins & Hormones

•Therapeutic drugs and medicines

•Like vaccines or cough syrup

•Local anesthetics


FAQ’s on Propylene Glycol

  • Other than one of the liquids used to create e-liquids, what other types of products contain PG?

    • PG is used in many everyday products from cosmetics & toiletries, food, animal feed, also in medicines and vaccines.

  • Do I use PG everyday without even knowing it?

    • Most likely yes. As PG is commonly used in face creams, shampoo, sprays, lotions, in sodas, candies, in other foods and also in medicines.

  • What happens to PG once it gets in my body?

    • In your body, under normal circumstances of low exposure, PG is quickly metabolized and excreted by your body in about 48 hours. 

  • Is it possible for me to ingest too much PG?

    • PG is manufactured and used under very strict guidelines (especially for the pharmaceutical grade version used in VOLCANO eCigs eliquid), so it’s not easily available to consumers as a pure product. With that being said, under normal circumstances it is impossible to ingest a large amount of PG, especially since consumer exposure to PG in everyday products is extremely low.  Also, many studies have shown and proven that PG’s toxicity is very low, by volume alcohol is actually more toxic than PG.

  • Can PG have negative health effects to a person who is consuming it over a long period of time and in small amounts?

    • PG has been used safely for many decades and in very many different applications. From studies that have been conducted, there have been no negative health effects from exposure to small amounts over time. The FDA has placed Pharmaceutical grade PG on the GRAS list which proves its safety in the use of consumable products.

  • How pure is pharmaceutical grade Propylene Glycol?

    • Propylene glycol USP/EP (pharmaceutical grade) has a very high purity and is manufactured and used under very strict guidelines. Its purity is more than 99.7%, which is extremely high for a chemical. Other than it being placed under rigid manufacturing and use guidelines, its transportation and processing is also very controlled and strict.

  • Is PG really safe for human health? Can I have an allergic reaction to it?

    • As with all products and also foods, there is always a chance for an individual to be allergic to PG. However, PG has been used in consumable products for over 50 years in over 4,000 cosmetics and toiletries. And over this very long period of time, there has been no evidence of negative health effects to consumers.