Ultra-processing markers
Propylene glycol
Definition
What it is
Propylene glycol (E1520): industrial solvent used as a humectant and carrier for flavors and colors; restricted in EU food use to specific applications; accumulates in liver and kidneys at high doses.
On the label
Label names covered by this flag
- propylene glycol
- 1,2-propanediol
- e1520
Regulation
Regulatory status
- Canada Restricted
- European Union Restricted
Explainer
In plain language
Propylene glycol is a clear, syrupy liquid used in food as a humectant, meaning it holds moisture, and as a carrier that helps dissolve and spread flavors and colors. It keeps some products soft and prevents them from drying out. The same compound is also used in non-food industrial and pharmaceutical applications, which is part of why people notice it on labels.
Assessment
Why it is flagged
Propylene glycol is permitted as a food additive by the FDA and by EFSA, which re-evaluated it in 2018 and set an acceptable daily intake. EU food use is restricted to specific applications and levels rather than allowed broadly. Animal studies at high doses have observed effects on the liver and kidneys, but those doses are far above normal dietary exposure. Clear Label flags it at medium severity because it is an industrial-origin additive with restricted use in some markets, not because harm at typical food levels is established. Some users prefer to track it because it appears across many processed products at once.
In the aisle
Where it commonly shows up
- Cake mixes, frostings, and baked goods
- Flavored and dried snacks
- Salad dressings and sauces
- Ice cream and frozen desserts
- Drink mixes and flavorings
- Some soft candies
Practical
Reading the label
Look for 'propylene glycol', '1,2-propanediol', or the code 'E1520' on ingredient lists. It also hides inside 'natural and artificial flavors' or color blends, where it acts as the carrier rather than being listed on its own.
Alternatives
If you want to avoid it
Some people choose products that use glycerin or simply fewer flavor carriers, or fresher foods with shorter ingredient lists that do not need a humectant.
FAQ
Common questions
Is propylene glycol the same as antifreeze?
No. The toxic ingredient in most antifreeze is ethylene glycol, a different compound. Propylene glycol is sometimes used in non-toxic antifreeze products, but the food-grade form is permitted as an additive by the FDA and EFSA.
Is propylene glycol restricted anywhere?
The EU permits it only in specific food applications and levels rather than broadly. The FDA lists it as generally recognized as safe within limits, and EFSA set an acceptable daily intake in its 2018 review.
Citations
Sources
Citation
Primary reference
About this page: the definition, label names, severity, and regulatory chips come from the clearlabel ingredient taxonomy, the same data the scanner uses to score products. Research summaries describe associations reported in published studies, not diagnoses; individual responses vary. Scan any product with clearlabel to see which of its ingredients carry flags.