GUIDELINES FOR PRESCRIBING NICOTINE FOR ELECTRONIC CIGARETTES UNDER THE Download Table Is Propylene Glycol safe to vape?Professional Guide about PG Development of a Freeze Pour Sample Preparation Method for the GC Analysis of Semivolatile Flavouring Chemicals Present in E cigarette Refill Liquids LCGC International Construction of electronic cigarettes Wikipedia Can fruit flavored nicotine vapes be safe despite their appeal to kids? , , The FDA recently granted approval for a company to market mango, blueberry, and menthol flavored vapes, despite concerns 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.