Propylene glycol and vegetable glycerin are common ingredients in smoke equipment vapor, cosmetics, hair products, food, drinks, cigarettes, medicine and many more products. Vegetable glycerin allergy is rather exceptional. Most reactions are likely caused by an allergy into the plant oil the vegetable glycerin was derived from. Propylene glycol http://100mljuiceco74308.isblog.net/details-fiction-and-hemp-for-pets-13792972