Pet Food Ingredients

Pet Food and Treat Ingredient Propylene Glycol

Although it is on the FDA’s GRAS (Generally Recognized as Safe) list, many other experts don’t have much good to say about the safety of Propylene Glycol. What is this ingredient and why is it in some foods and treats?

Susan Thixton

Published

March 18, 2010

The FDA states propylene glycol is used as a humectant in soft-moist pet foods, which helps retain water and gives these products their unique texture and taste. Basically, propylene glycol is used as a preservative to soft-moist pet foods and treats. From the FDA website: “It was affirmed Generally Recognized As Safe (GRAS) for use in human and animal food before the advent of soft-moist foods. It was known for some time that propylene glycol caused Heinz Body formation in the red blood cells of cats (small clumps of proteins seen in the cells when viewed under the microscope), but it could not be shown to cause overt anemia or other clinical effects. However, reports in the veterinary literature of scientifically sound studies have shown that propylene glycol reduces the red blood cell survival time, renders red blood cells more susceptible to oxidative damage, and has other adverse effects in cats consuming the substance at levels found in soft-moist food. In light of these new data, CVM amended the regulations to expressly prohibit the use of propylene glycol in cat foods.” http://www.fda.gov/animalveterinary/resourcesforyou/ucm047113.htm

Wikipedia provides the following information for the safety of propylene glycol in animals: “Veterinary data indicates that propylene glycol is toxic to 50% of dogs at doses of 9mL/kg, although the figure is higher for most laboratory animals (LD50 at levels of 20mL/kg). However, propylene glycol may be toxic to cats in ways not seen in other animals. The U.S. Food and Drug Administration has determined that its presence in or on cat food has not been shown by adequate scientific data to be safe for use. Any such use is considered an adulteration of the cat food and a violation of the Federal Food, Drug, and Cosmetic Act.” http://en.wikipedia.org/wiki/Propylene_glycol#Animals

The Material Safety Data Sheet from the Department of Commerce provides the following warning regarding ingestion of propylene glycol: “May cause gastrointestinal irritation with nausea, vomiting and diarrhea. Low hazard for usual industrial handling. May cause emoglobinuric nephrosis. May cause changes in surface EEG.” http://www.sefsc.noaa.gov/HTMLdocs/PropyleneGlycol.htm

Most scientific data on the safety of propylene glycol is based on use in cosmetics and skin conditioning products (human). Environmental Working Group’s Skin Deep section (a cosmetic safety database) states their researchers reviewed available research and found that this ingredient is linked to cancer, developmental/reproductive toxicity, allergies, and skin, eye, and lung irritation. Again in relation to skin, EWG gave the ingredient a ‘moderate hazard’ rating. http://www.cosmeticsdatabase.com/ingredient.php?ingred06=705315

In my book, propylene glycol is another one of those ingredients that it’s just not worth the risk.

Wishing you and your pet(s) the best,

Susan Thixton
Pet Food Safety Advocate
Author, Buyer Beware
Co-Author Dinner PAWsible
TruthaboutPetFood.com
PetsumerReport.com

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