If you're allergic to propylene glycol then you're allergic to pretty much everything.

That same propylene glycol is used in cakes/cupcakes, frostings, many ice creams, beers (as a foaming agent), some coffees, candy, many salad dressings, flavoured coffees, dried fruits, some brands of milk, many beauty products (makeup, shampoo, soaps)...

There are a lot more people with peanut allergies and we don't ban people from eating products containing peanuts anywhere in public. Why is this case different?