When reading ingredient labels on packaged foods, you might occasionally spot “propylene glycol” and wonder what a compound commonly associated with industrial applications is doing in your diet. Propylene glycol (PG) is a synthetic organic compound that serves several functional roles in modern food processing. From maintaining moisture in baked goods to evenly dispersing flavors in beverages, it helps preserve texture, stability, and shelf life across a wide variety of everyday products.
Why Is Propylene Glycol Used in Food?
Before identifying specific food categories, it helps to understand why food manufacturers rely on propylene glycol in the first place. PG is a colorless, odorless, slightly viscous liquid that is soluble in water and organic solvents. In the food industry, it performs several key chemical and physical functions:
- Humectant: It absorbs water and prevents packaged foods from drying out, keeping soft bakery products and intermediate-moisture foods tender over long periods.
- Flavor Solvent & Carrier: Many aromatic compounds and essential oils used for flavorings do not dissolve easily in water. Propylene glycol acts as an effective solvent, ensuring uniform flavor distribution.
- Emulsifier & Stabilizer: It helps mix water-based and oil-based ingredients that would otherwise separate, such as in liquid dressings, sauces, and dessert toppings.
- Texturizer & Anti-Caking Agent: It improves mouthfeel and prevents clumping in powdered mixes or processed dairy formulations.
Common Foods That Contain Propylene Glycol
Baked Goods & Cake Mixes
Propylene glycol is mainly used as an emulsifier in food additives and is also an excellent solvent for flavorings and colorings. Packaged cakes, muffins, donuts, and brownies frequently contain propylene glycol to maintain moisture levels during distribution. It prevents baked goods from becoming stale or dry on supermarket shelves. Additionally, ready-to-bake cake mixes and pre-made frostings use PG to keep fats and liquid flavorings evenly dispersed.
Liquid Flavorings & Extracts
Many commercial sodas, iced teas, and squeeze-bottle liquid water enhancers use PG to dissolve citrus oils and artificial flavors. Without a solvent like propylene glycol, these concentrated flavor compounds would separate and float to the top of the container.
Processed Dairy & Frozen Desserts
Commercial ice creams, frozen yogurts, and whipped toppings often include propylene glycol or propylene glycol esters of fatty acids. In ice cream, it lowers the freezing point slightly, which reduces the formation of large ice crystals and yields a smoother, creamier texture that remains scoopable even straight from the freezer.
Condiments, Dressings, and Sauces
Premade salad dressings, barbecue sauces, and liquid marinades often rely on PG as a stabilizer and emulsifier. It prevents oil-and-water separation while ensuring spices and herbs remain evenly suspended throughout the liquid.
Packaged Snacks & Confectionery
Gummy candies, marshmallow-based treats, and soft chewy candies sometimes incorporate propylene glycol to retain moisture and sustain elasticity over time.
Is Propylene Glycol Safe to Consume?
Safe for consumption, but subject to strict scope-of-use limitations.
According to national standards, the safe intake of propylene glycol complies with the benchmark set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), which specifies an Acceptable Daily Intake (ADI) of no more than 25 mg per kilogram of body weight. For context, most people consume far more salt than this on a daily basis.
For an adult weighing 70 kg, the maximum daily intake is 1.75 grams. Currently, in the production of baked goods such as cakes, when propylene glycol is used as an additive, the common industry practice is to limit its content to no more than 3 grams per kilogram of the final product.
Fudan University School of Public Health: Propylene Glycol Causes No Pathological Changes in Kidneys
According to a report published by CNR.cn in 2019, Journal of Hygiene Research—a Chinese Natural Science Core Journal supervised by the Ministry of Health and sponsored by the Chinese Center for Disease Control and Prevention—published an article in March 2007 detailing research on propylene glycol toxicity from the School of Public Health at Fudan University. To determine which organs and tissues propylene glycol might damage, the research team designed toxicity tests with low, medium, and high dosage regimens across three different structural types of propylene glycol.
The results showed that none of the propylene glycol structural types induced significant pathological changes in the kidneys.
“To date, the conclusion that propylene glycol causes kidney damage has never been substantiated, nor have there been outbreaks of mass health incidents, nor is there definitive evidence from basic research,” said Zhang Yimin, Director of the Second Department of Nephrology at the Sixth Affiliated Hospital of Sun Yat-sen University. He added that as a food additive, the safety of propylene glycol has been certified by the U.S. FDA, and it serves as a carrier for a wide variety of pharmaceuticals and foods.
How to Identify Propylene Glycol on Labels
If you prefer to limit your exposure to processed food additives, you can identify propylene glycol on packaged ingredient lists under several common designations:
- Propylene Glycol
- Propane-1,2-diol
- E1520 (European food additive code)
- Propylene Glycol Esters of Fatty Acids / E477 (Propylene glycol combined with fatty acids for emulsification)
