Each product is formulated with the correct balance of ingredients, each with a specific purpose. We use propylene glycol to help keep the semi-moist kibbles soft and moist.
Propylene glycol is quite different from ethylene glycol, the anti-freeze used in automobiles. Propylene glycol is approved as a food additive in human food and in feed for animals, except cats, in the U.S. and Canada.
Ethylene glycol — not propylene glycol -- is the active compound in most automobile radiator anti-freeze solutions, and is toxic to animals and humans when ingested. Propylene glycol has a different molecular structure, giving it different properties and allowing it to be used safely in animal feed, except for cats, as well as in human foods, such as cake mixes, salad dressings, soft drinks, popcorn, food coloring, fat-free ice cream and sour cream.
Propylene glycol can be used as a non-toxic anti-freeze, just as salt can be used as an "anti-freeze." The differences in the molecular make-up of propylene glycol and ethylene glycol have significantly different impacts on health and safety for humans and pets. Propylene glycol is approved for use by the Food and Drug Administration (FDA).