PG and VG are often utilized as a solvent for vaping mixtures of tobacco and cannabis products, and both are considered safe by the USFDA. Some controversy exsists as to whether they are safe for vaping. PG is generally recognized as safe for human consumption, and is found in many food products, such as coffee-based drinks, liquid sweeteners, ice cream, whipped dairy products and soda. Consumption of very large quantities can result in toxicity, but these levels would be very hard to acheive, especially when vaping. If rash or shortness of breath occurs while vaping, a rare allergy may exist. VG is also considered safe and is used in pharmaceutical preparation and as a sweetener and preservative.