Propylene Glycol
Caution for cats
Propylene glycol (a moisture-keeper) can damage cats' red blood cells and is banned from cat food in the US. It's still allowed in dog food.
- US Code of Federal Regulations, 21 CFR 589.1001 — Propylene glycol in or on cat food
- Merck Veterinary Manual — Propylene Glycol Toxicosis in Animals
- US Code of Federal Regulations, 21 CFR 582.1666 — Propylene glycol (GRAS, except in cat food)
- FDA final rule, 61 FR 19542 (1996) — GRAS Status of Propylene Glycol; Exclusion of Use in Cat Food
That the E-number names this substance: Commission Regulation (EU) No 231/2012 — specifications for food additives
Sources checked 2026-10-12. If you think a pet has eaten something harmful, contact your vet or an animal poison control line straight away. This is not veterinary advice.
The short version
A versatile humectant and carrier solvent — common in cake icings, flavor extracts, and e-cigarette liquids.
For people, it's a common carrier and moisture-keeper considered safe at the amounts used in food — that's what the green means. Cats are different: it's banned from cat food in the US. See "In pet food" above.
Safety profile
ADI of 25 mg/kg body weight. Generally well-tolerated. Metabolized to lactic acid and excreted; very different toxicity profile from ethylene glycol. Caution at high intake for infants (limited metabolic capacity). Cats are different: propylene glycol can damage cats' red blood cells, and it is banned from cat food in the US (21 CFR 589.1001; Merck Veterinary Manual).
Sources
- EFSA ANS Panel: Re-evaluation of propane-1,2-diol (E 1520) as a food additive. EFSA Journal 2018;16(4):5235 — European Food Safety Authority (EFSA Journal), 2018. ADI of 25 mg/kg bw; metabolism to lactic acid
- Regulation (EC) No 1333/2008, consolidated text of 18.08.2026 (Annex III, carriers and flavourings) — Publications Office of the European Union, 2026. EU use only as carrier, with maximum levels from all sources
- 21 CFR 184.1666 Propylene glycol (GRAS, maximum levels by food category) — US FDA / Office of the Federal Register (eCFR), 1982. US maximum levels per food category (97% in seasonings and flavorings)
- 21 CFR 589.1001 Propylene glycol in or on cat food — US FDA / Office of the Federal Register (eCFR), 1996. Prohibited in cat food in the US
Checked against these sources on .
Educational information only. Not medical, dietary or veterinary advice. Spotted an error? Tell us.