Vaping Products That Look Like Juice Boxes and Candy Are Target of Crackdown The New York Times How to Choose A Vape Juice Flavour Beginner's Guide Do you know what you're vaping? Propylene glycol (PG) and vegetable glycerin (VG) are the main liquids in vapes. When heated, these chemicals turn toxic and aren't safe to breathe. What Does Vaping Do to Your Lungs? Johns Hopkins Medicine