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Propylene Glycol

Poisonous to: Cats, Dogs

Level of toxicity: Generally mild to moderate, depending on the amount ingested and if ethylene glycol is present

Common signs to watch for:

  • Severe sedation
  • Stumbling
  • Seizures
  • Tremors
  • Panting
  • Disorientation
  • Lethargy
  • Metabolic acidosis

Propylene glycol is one of the least toxic glycols. It is a synthetic liquid substance that absorbs water and is used by the chemical, food, and pharmaceutical industries for a wide variety of reasons. Like ethylene glycol, propylene glycol may be used as an antifreeze and can be found in high concentrations in RV and “pet safe” antifreezes. Since it has a wider margin of safety as compared to its chemical cousin, ethylene glycol, it is commonly used to absorb extra water and maintain moisture in certain medicines, cosmetics, or dog and human food products and is categorized by the FDA as a GRAS (generally recognized as safe) substance for this use. It is also used as a solvent for food colors, flavors and pharmaceuticals (i.e. injectable diazepam). Cats are particularly sensitive to PG and its use is not allowed in cat foods. Historically, some semi-moist cat foods contained up to 5-10% PG and cats were harmed by this (Heinz body formation).

If cats or dogs ingest large amounts of propylene glycol, poisoning can occur. This is most commonly seen when pets ingest liquid propylene glycol products.

Poison type: Garage Items

Alternate names: Pet-safe antifreeze, PG,