Ever puffed a vape around others thinking it's harmless? Think again. Inhaling vapor from e cigarettes exposes you to harmful chemicals, such as formaldehyde. These toxic substances can be passed on to Don't Be Fooled, E cig Aerosol Is Not Harmless for Kids American Lung Association Can I be Affected by Secondhand Vape Smoke? Researchers Warn of Potential Harm From E Cigarette Secondhand Vapor AZPM Secondhand e cigarette aerosols expose kids to less nicotine than cigarettes, study finds, but can still be risky CNN