Food-grade glycol (also called propylene glycol) is one of the most versatile food additives in the world today. It’s no exaggeration to say that food as we know it would be totally different without food-grade glycol. Even so, it’s not well known to most people, and there are many questions about it.
Let’s explore some of the biggest questions about propylene glycol:
1. What Is Propylene Glycol?
Propylene glycol appears as a colorless, thick liquid with a very mild aroma. It can be used in various ways depending on how it is synthesized and prepared. In an industrial context, propylene glycol is principally used as a coolant. It is one of the only coolants that meets the needs of modern wineries.
Food-grade propylene glycol appears as a food additive. It is found mainly in salad dressings but can also be used in other foods. It helps products maintain the consistency, moisture, and texture that a discerning consumer expects. You can find it in seasonings, soup blends, teas, soft drinks, and more.
a. What is the difference between USP/food-grade and industrial-grade propylene glycol?
USP (or food-grade) propylene glycol is a highly controlled substance that must be produced according to extremely strict industry and regulatory standards. Food-grade propylene glycol is safe and is absorbed by the body readily. It is metabolized quickly and has a metabolic half-life of only about two to four hours.
Since USP propylene glycol is not available directly to the public, it is impossible to consume it in the extraordinary amounts that might provoke a toxic reaction. By comparison, industrial-grade propylene glycol is not intended for consumption and is not thoroughly tested for impurities that might be dangerous to humans. It should only be used as directed by professionals in a controlled setting.
2. Why Is Propylene Glycol Used in Food?
There are about two dozen different kinds of foods that typically contain propylene glycol. The majority of these foods are powdered blends and mixes. All forms of powdered food need anticaking agents and protection against moisture intrusion that would otherwise render the foodstuff hazardous. Many brands prefer propylene glycol because it not only works as a preservative but also enhances flavor.
Imagine your favorite baking mix, such as a cake, muffin, biscuit, or cinnamon roll mix. What ensures that it will actually have the satisfying texture and “mouth feel” you expect? Propylene glycol is a big part of the answer. It serves to emulsify and texturize the resulting baked goods.
3. Is Propylene Glycol Safe?
Food-grade propylene glycol is “generally recognized as safe” by the Food and Drug Administration (FDA). “Generally safe” may not seem like a ringing endorsement, but it aligns with how many additives, including the most common food dyes, are treated in regulatory language.
4. How Do You Dispose of Propylene Glycol?
Food-grade propylene glycol is only available in finished products and can be disposed of safely by consuming or destroying those products. Industrial propylene glycol can be used as directed in your vehicle or HVAC system.
In general, industrial propylene glycol expires two years from the date of manufacture when it is kept in appropriate conditions—fully sealed and out of direct sunlight in temperatures below 100°F. Expired or compromised propylene glycol should never be poured down drains. Instead, contact a qualified waste disposal company that can haul it away in appropriately marked containers.
Browse our selection of propylene glycol to learn more or order your own.