As you put away the flour from making pancakes, you glance into the pantry and notice a second box of that cake mix you used for your last Thanksgiving dinner. You remember how tasty the cake was, and how moist it stayed, even after a week. You may wonder, “How could cake made from a simple box mix maintain its texture so well?” And before you know it, you’re craving it again! You can thank the food ingredient known as propylene glycol for helping your cake stay moist and intact for so long. But what exactly is propylene glycol, and how did it get into your cake mix?
What is propylene glycol?
Propylene glycol is a synthetic liquid that is clear, colorless and tasteless. The U.S. Food and Drug Administration (FDA) considers propylene glycol safe for a variety of uses, including for the absorption of extra water in our foods, in medication, and in cosmetics so that they maintain their moisture and preserve color and consistency. Propylene glycol also helps to dissolve ingredients that are added to products so that the product forms an ideal consistency. It’s also a safe food additive that exhibits low levels of toxicity within the body.
What foods contain propylene glycol?
Propylene glycol is approved for use in many processed and packaged foods, including:
- Baked goods and desserts
- Prepared meals
- Baking and flavoring mixes
- Most fast food
- Soft drinks
- Some breads
- Canned beans
- Dairy products
- Flavors and colors used in food products
Considering all the foods that propylene glycol is added to, it’s also helpful to know that it functions in food as a humectant (pulling moisture toward it) and solvent (helping to dissolve one ingredient in another). Propylene glycol is also an anti-caking agent, antioxidant, dough strengthener, emulsifier, flavor agent, formulation aid, stabilizer and thickener, glazing agent, texturizer, and antimicrobial agent (helping to kill or slow the growth of microorganisms, like bacteria or fungi that may contaminate food). While this information may be helpful to know, you may wonder if propylene glycol is safe to consume.
How safe is propylene glycol?
The FDA reviews scientific research and safety trials to confirm whether a food additive, like propylene glycol, is safe for use in the body. In 1982, the FDA approved propylene glycol as a safe food additive and deemed it a “Generally Recognized as Safe,” or GRAS, ingredient. In doing so, the FDA set strict guidelines so that the maximum amount of propylene glycol that is used in a food product would not exceed the levels that were considered safe. In keeping with this restriction, manufacturers are only allowed to use a certain amount of propylene glycol based on food and beverage types. Further, the World Health Organization (WHO) has set daily intake restrictions so that consumers and food companies remain aware that the acceptable dietary intake, or ADI, for propylene glycol is 25 mg for every kilogram (kg) of body weight. Both efforts, by the FDA and the WHO, ensure our safety when consuming foods containing propylene glycol.
While it can be hard to calculate the amount of propylene glycol in each food product you eat, it is likely that you will not consume propylene glycol in toxic amounts. Most products contain small amounts of propylene glycol, and it degrades rapidly in the body.
Putting propylene glycol in perspective
Propylene glycol is used in many products to help preserve their moisture and consistency. It is considered safe for use in food, particularly because it is present in small amounts. Where concern may arise is in frequent use of medications that have a high amount of propylene glycol, or when it is applied topically through cosmetics or personal care products. In these instances, talk to your doctor to consider alternate intakes, applications, or product options.
This article was written by Casey Terrell, MPH, RD.
“Propylene Glycol.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine. 1999.
McMartin, K. “Propylene Glycol.” Encyclopedia of Toxicology (Third Edition), Academic Press, 14 April 2014.
CFR – Code of Federal Regulations Title 21, U.S. Food and Drug Administration, 2020.
Propylene Glycol, World Health Organization, 2002.
Questions and Answers about Propylene Glycol, Food Insight, 2014.