It's NOT just water vapor. Vaping exposes your lungs to harmful chemicals and can affect your overall health. This Vaping Awareness Month, get the facts and free support to quit. Text READY April 7, 2014: What are electronic cigarettes and why are they so popular? Tennessee Poison Center FREE 24 7 Poison Help Hotline 800.222.1222 Propylene Glycol in E Cigarettes Is PG Dangerous to Inhale? E Cigarette Direct Dire Warnings by Big Tobacco on E Smoking The New York Times Vapes on black market may contain toxic chemicals, pesticides, harmful flavorings Propylene glycol, a component of electronic cigarette liquid, damages epithelial cells in human small airways Respiratory Research Springer Nature Link