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. Propylene Glycol 100% PG Nicokits at Masquevapor Nicotine, propylene glycol, sweet flavorings, and various toxic chemicals like carcinogens and heavy metals are found in vape juice, posing health risks, especially to youth. LNW Blog PG vs VG Which PG VG Ratio is Best?