Some persons who are sensitive to propylene glycol notice a flare when they eat certain foods that contain the chemical.  If you suspect this, it may be worthwhile to try to avoid it for one month to see if you start to improve.  

It does not naturally occur in foods, so it will always be listed as an ingredient if present.  Usually foods that are or were a liquid or batter or mix at some point.  

Be careful at restaurants – they will not know if propylene glycol is in the food.

These may contain PROPYLENE GLYCOL:

• Salad dressing – esp. ranch (e.g. some Ken’s, Kraft, Marie’s, Pfeiffer, T.Marzetti, Wishbone)
• Dressings (e.g. Taco Bell)
• Sauces – steak, horseradish, tartar, Dijon
• Biscuits 
• Brownie mix
• Cake mixes (e.g. Betty Crocker, Duncan Hines, Pillsbury Plus)
• Cheesecake mix (e.g. Jello)
• Coconut (e.g. Baker’s, Durkee)
• Cream pie mix
• Cupcakes (e.g. Hostess)
• Desserts (e.g. Sara Lee cakes, cheesecakes)
• Donuts (e.g. Hostess)
• Food flavoring (not a problem in small amounts)
• Food coloring (not a problem in small amounts)
• Ice cream 
• Macaroni and cheese
• Marinades (e.g. KC Masterpiece)
• Orange bitters, Angostura
• Popcorn (e.g. Wise butter flavored)
• Potato salad (e.g. Grandma’s)
• Snack foods – (Durkee & French’s potato sticks, French-fried onions)
• Sour cream
• Store-bought cakes (e.g. Pepperidge Farms)
• Whipped topping mix (e.g. Dream-Whip)