A past blog post discusses the usability of each substance for a buffer vial. Apart from this particular application, propylene glycol is a common ingredient in a variety of food, cosmetic, and industrial products. It's also continually listed on lists of "Gross Food Ingredients" that can be found in any corner of the web. Still, the question remains, what exactly is propylene glycol, and how common is it as an ingredient in preserving perishable food in the fast food industry?
The first answer is a bit complicated. The Agency for Toxic Substances and Disease Registry (ATSDR) released a toxicological profile for Propylene Glycol in 1997. This is extracted from Section 1.1:
“Propylene glycol is a synthetic liquid substance that absorbs water. Propylene glycol is also used to make polyester compounds, and as a base for deicing solutions. Propylene glycol is used by the chemical, food, and pharmaceutical industries as an antifreeze when leakage might lead to contact with food. The Food and Drug Administration (FDA) has classified propylene glycol as an additive that is "generally recognized as safe" for use in food. It is used to absorb extra water and maintain moisture in certain medicines, cosmetics, or food products. It is a solvent for food colors and flavors, and in the paint and plastics industries. Propylene glycol is also used to create artificial smoke or fog used in fire-fighting training and in theatrical productions.”
With that said, public opinion and some studies have shown that (despite rigorous testing and assurance) propylene glycol may have adverse health effects. The Environmental Working Group (EVG) classifies the substance as a “moderate hazard” due to being “classified as expected to be toxic or harmful” to the Organ system based on Canada’s domestic substances list. Whatever the case may be, it’s no secret that Propylene Glycol exists in many of the products that we use.
Fast Food Restaurants That Use Propylene Glycol
Shifting the focus to fast food, propylene glycol has long been established as an excellent additive for mass food distribution and storage, and it continues to be used constantly in the fast food industry. Drawing data from the corporate websites and nutritional information sheets, here is a short (but complete) list of the fast food products that contain propylene glycol. We’ll focus primarily on the “Big 3” (McDonald's, Wendy’s, and Burger King) and all relevant ingredients will be included.
Soybean Oil, Water, Distilled White Vinegar, Buttermilk (cultured lowfat milk, milk, nonfat dry milk, salt, sodium citrate, vitamin apalmitate), Corn Syrup, Egg Yolks and Enzyme Modified Egg Yolks, Sugar, Contains 2% or Less of: Salt, Modified Corn Starch, Torula Yeast, Lactic Acid, Phosphoric Acid, Sodium Benzoate and Potassium Sorbate (preservatives), Garlic Powder, Polysorbate 60, Xanthan Gum, Onion Powder, Disodium Inosinate, Disodium Guanylate, Spice, Natural Flavor, Cultured Cream, Parsley (dehydrated), Enzyme Modified Milk, Calcium Disodium EDTA (to protect flavor), Propylene Glycol, Buttermilk Powder, Molasses, Soy Lecithin. CONTAINS: EGG, MILK, SOY.
Soybean oil, water, high fructose corn syrup, vinegar (balsamic, cider), apple juice concentrate, egg yolk, contains less than 2% of: sugar, natural flavor, salt, xanthum gum, potassium sorbate and calcium disodium EDTA as preservatives, spice, onion, garlic, propylene glycol alginate, citric acid.
Cucumbers, Water, Vinegar, Salt, Calcium Chloride or 1/10 of 1% Sodium Benzoate as a preservative, Alum and/or Propylene Glycol, Polysorbate 80, Natural Flavors+, Yellow #5, Turmeric Oleoresin, Blue #1, Soy Lecithin. Natural flavors from plant sources.
Soybean Oil, Sweet Relish(Cured Cucumbers, High Fructose Corn Syrup, Vinegar, Onion, Salt, Red Bell Peppers, Xanthan Gum, Sodium Benzoate And Potassium Sorbate (Preservatives), Natural Flavorings, Calcium Chloride, Polysorbate 80, Turmeric), Sugar, Water, Distilled Vinegar, Tomato Paste, Egg Yolk. Contains Less Than 2%: Salt, Dehydrated Onion, Xanthan Gum, Sodium Benzoate And Potassium Sorbate As Preservatives, Natural Flavors, Propylene Glycol Alginate, Polysorbate 60, Caramel Color, Oleoresins Paprika And Turmeric (Color), Canola Oil, Calcium Disodium EDTA Added To Protect Flavor. Natural Flavors from plant sources.
Milk fat and Nonfat Milk, Sugar, Sweet Whey, Corn Syrup, High Fructose Corn Syrup, Propylene Glycol Monoesters, Natural and Artificial Vanilla Flavor, Mono & Diglycerides, Guar Gum, Disodium Phosphate, Sodium Citrate, Cellulose Gum, Carrageenan.
Milk fat and Nonfat Milk, Sugar, Sweet Whey, Corn Syrup, High Fructose Corn Syrup, Propylene Glycol Monoesters, Natural and Artificial Vanilla Flavor, Mono & Diglycerides, Guar Gum, Disodium Phosphate, Sodium Citrate, Cellulose Gum, Carrageenan.
In the interest of spacing, McDonald’s products were listed without their entire ingredient list. What can be observed is a significant divide that exists between the fast food giants on the usage of Propylene Glycol. Wendy’s, according to their own nutritional website, lists only one product (a dipping sauce) that contains Propylene Glycol.
Burger King, similar to Wendy’s, lists only one sauce as containing the ingredient in the midst of a handful of sauce variations. Yet, Burger King is using propylene glycol in a handful of other products, including the ever-so-necessary pickles (which are included in every Burger Sandwich).
McDonald's lists up to 10 products that contain Propylene Glycol, including the famed ‘Big Mac’ sauce. In truth, the scientific applications of the product (that is, why it's in the food to begin with) are well documented and well detailed by the FDA. As stated, Propylene Glycol has a hand in many industries and products, including bathtubs, small boats and water/chemical tanks and pipes. Other end use application areas are paints and coatings; airplane de-icers/anti-icers; antifreeze and industrial coolants; detergents; hydraulic fluids; and cosmetics. Our blog post also outlined the benefits of a Propylene Glycol-filled buffer vial for use in vaccine refrigeration.
For more information on Propylene Glycol and usage, visit the DOW index on Propylene Glycol for other industrial and commercial applications.