Propylene glycol
البروبيلين غلايكول
Additive (species-restricted) · CAS: 57-55-6
Banned in cat food - fine for dogs
Why this verdict
SPECIES-SPLIT exemplar (mirror of xylitol). FDA PROHIBITS propylene glycol in/on cat food (21 CFR 589.1001) - RBC/Heinz-body effects in cats; use adulterates the feed. GRAS for animal feed in other uses, including dog food (Dog = okay; humectant, no nutritional benefit). Step A hard-flag, cat.
What It Is
A humectant (moistening agent) used in some semi-moist foods.
The other half of the species split: the FDA prohibits propylene glycol in cat food because it damages cats’ red blood cells, yet it’s recognised as safe in dog food. On a cat-food label it’s a hard stop - and never feed a PG-containing dog food to a cat. For dogs it’s a permitted moistening agent with no nutritional upside.
Evidence & Status
For Dogs & Cats
Dogs
Okay
Cats
Skip
AAFCO / FDA status
GRAS for dog food; PROHIBITED in cat food (21 CFR 589.1001). Live FDA Import Alert 72-06 (updated 2026) detains PG-containing cat food.
Applies to
cat
Halal Status: Halal
Synthetic; permissible. (Cat-food prohibition is a safety, not a halal, matter.)
Standard: MS 1500:2019; GSO 2055-1; JAKIM e-SMAF
Also Known As
1 · 2-propanediol · PG · E1520
Primary Source
Evidence, not medical advice. You decide.
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