I am extraordinarily allergic to the glycol in e-cigs. Just a few seconds of exposure is enough to send me into anaphylaxis. I am pretty sure somebody tapping away on their phone wont kill you.
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?