99.9% Pure USP (Pharmaceutical Grade) Propylene Glycol.Also used in various edible items such as coffee-based drinks, liquid sweeteners, flavour concentrates, ice cream, whipped dairy products, soda etc.
What Is Propylene Glycol?
Propylene glycol (often referred to as PG) is the third “product” in a chemical process beginning with propene, a byproduct of fossil fuel (oil refining and natural gas processing) and also found in nature as a byproduct of fermentation. Propene is converted to propylene oxide, a volatile compound used frequently in the creation process of polyurethane plastics (and to create propylene glycol). Propylene oxide is considered a “probable carcinogen.” Finally, through a hydrolyzation process (separating molecules by the addition of water), you get propylene glycol.
A synthetic liquid substance that absorbs water, propylene glycol classified by the chemical formula C3H8O2. Propylene glycol (1, 2-propanediol) is an organic compound (a diol alcohol) and is a tasteless, odorless and colorless clear oily liquid. (1a) Another name for it is “propane-1,2-diol,” which is sometimes used when listing it as a compound on ingredient labels. As it’s found in food as an additive (in the U.S., at least), the U.S. Department of Agriculture refers to it via the E-number E1520. It’s completely soluble in water, and one major purpose it serves is as a “vehicle” for topical products, such as lotions.
Propylene glycol is found in thousands of cosmetic products as well as a large number of processed foods products. Another place you will find it is in many medications, serving as a way to help your body absorb chemicals more efficiently. It’s also a common ingredient in electronic cigarettes, contributing to taste and “smoothness” of the smoke.
This liquid substance is fraught with inconsistencies in research, as well as many differing opinions on whether propylene glycol is a dangerous toxin or a mostly harmless compound. There is no hard and fast answer to that question, however — according to a fair amount of research, the effects of propylene glycol are rarely negative and generally associated with extremely large, intravenous dosage levels.
It’s certainly less dangerous than, for example, ethylene glycol, a toxic chemical compound still used in many types of antifreeze and other household products. Ethylene glycol is considered poisonous and sometimes ingested (purposefully or by accident), requiring immediate medical attention for its toxic substances. Because of its sweet taste, ethylene glycol in antifreeze has been responsible for the deaths of many household pets who would lap it up when it collected on the ground. When propylene glycol is used in antifreeze products in place of ethylene glycol, it’s considered “non-toxic antifreeze.”
That doesn’t necessarily quell concerns, however. Many people are extremely concerned by the presence of an ingredient in antifreeze (one that’s used to deice airplanes, no less) in their food, which has sparked uproar in recent years, especially when three European countries pulled a popular alcoholic drink off the shelves for an illegal level of propylene glycol. (1b) The mix-up apparently occurred when the company sent the North American formula instead of the European formula, which contains six times less propylene glycol.
Consumers were amazed and frustrated to hear that their favorite foods and drinks might contain the chemical, exacerbated by its presence in so many other daily products. Many people became scared of the association between antifreeze and food, although propylene glycol simply lowers the freezing point of water (just like salt) and was only introduced into antifreeze products to replace a more dangerous chemical.
The body of research surrounding this substance is considered “fair,” according to the Environmental Working Group’s assessment. It rates propylene glycol a “3” on its health concerns scale, meaning the hazard it presents is moderately low. (2) It (correctly) designates the known issues with propylene glycol to be in the “allergies and immunotoxicity” category, with no hazard related to cancer or reproductive processes. Again, this information reflects available research.
There are a few important things to consider in our discussion on toxicity information and propylene glycol:
- It’s not “bioaccumulative.” This means that, in normal dosage or exposure levels, propylene glycol breaks down in the body within 48 hours in individuals with healthy kidney and liver function and does not accumulate over time to create toxicity in the body. (3)
- Propylene glycol is found in industrial-grade levels in products like antifreeze, polyurethane cushions, paints and the like. In food, the levels are considered pharmaceutical-grade.
- The Food and Drug Administration (FDA), in a toxicological profile, has deemed propylene glycol as “generally recognized as safe.”
- In the Centers for Disease Control and Prevention’s exhaustive report of the effects and possible toxicity of propylene glycol, no major health concerns were found. However, the organization states in the report that, “No studies were located regarding respiratory, cardiovascular, gastrointestinal, musculoskeletal, hepatic, renal, endocrine, dermal, ocular, or body weight effects in humans, or musculoskeletal, dermal, or ocular effects in animals after oral exposure to propylene glycol.” Similar statements were made about skin exposure and inhalation exposure. (4) (Nearly all the research used to support the “safety” of this chemical was done on rats, horses or monkeys — and a great deal of the points were made based on a study done on monkeys more than 60 years ago.)
The first three of these points seem to be encouraging. Although this chemical compound is not generally found in nature, it seems to be potentially safe. But what concerns me most is what is not found there — any sort of extensive human-based research on its safety.
Let’s take a look at the current research and potential effects of propylene glycol.