Propylene Glycol and Vegetable Glycerin 2 Pack: one PG and one VG, 500 mL (1.06 Pint) Each with Dispensing Caps; USP, Food Grade, Kosher: Amazon.com: Industrial & Scientific Comparative study of lung toxicity of E cigarette ingredients to investigate E cigarette or vaping product associated lung injury ScienceDirect 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 What Are the Ingredients in Vape Juice? PG vs. VG: What's the Difference?