DYK? Vaping coats lungs with potentially harmful chemicals. This can include chemicals such as: Diacetyl: This food additive, used to deepen e cigarette flavors, is known to damage small passageways in the lungs. Your vape isn't producing formaldehyde, either Vapour.com Electronic Cigarettes, E Cigs, and E Liquids for Vaping Vapour Clinical Studies Juul Labs Science Study: Juul Pods Contain Caffeine. What's It Doing There, And What Does It Do? What is JUUL?