3 Dangerous Chemicals Found in Vapes Explained Dangerous Chemicals in Vapes You Should Know 1 in 3 teens who vape say they get e cigarettes online, including through social media apps. (PMC study) Parents: Monitor online activity, start the conversation, and stay informed. Learn more at PG vs. VG: What's the Difference? The combination of propylene glycol and vegetable glycerin e cigarette aerosols induces airway inflammation and mucus hyperconcentration Scientific Reports 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.