Propylene glycol is used in e cigarettes to produce a smoke like vapor. It's also used in anti freeze. Danger: Can cause eye, throat, and airway irritations. Visit our website to learn more about the Ultrasonic Cigarettes: Chemicals and Cytotoxicity are Similar to Heated Coil Pod Style Electronic Cigarettes Chemical Research in Toxicology Low temperature (< 200 C) degradation of electronic nicotine delivery system liquids generates toxic aldehydes Scientific Reports Adolescent Perspectives on the Pharmacy Based T EVER (Teen E Cigarette and Vaping Educational Resource) and Its Potential Impact on Youth Vaping 1,2 Propylene Glycol: A Biomarker of Exposure Specific to e Cigarette Consumption