Can Expired Vape Juice Kill You? [Shocking Facts] Grey Haze UK Vapes laced with spice drug sold to schoolchildren on Snapchat 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. Why Do I Feel Sick After Vaping? Here's What You NEED to Know! What Does Vaping Do to Your Lungs? Johns Hopkins Medicine Vaping the sweetener sucralose may produce toxic chemicals