PG vs. VG A Vapers Guide SMOKO E Cigarettes SMOKO E Cigarettes Heated Tobacco Products and E cigarettes What's the difference? Dailynewsegypt Heated Tobacco Products, Cigarettes, and E Cigarettes: What's the Difference PMI Science Stop Smoking E Cigarettes CardioSmart American College of Cardiology Propylene glycol, a component of electronic cigarette liquid, damages epithelial cells in human small airways Respiratory Research Springer Nature Link While vaping is not risk free, it is less harmful than tobacco Our World in Data