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 Hidden Dangers of Secondhand Vaping Emory Health Digest First, Second and Thirdhand Smoke: The Differences and Dangers Tobacco Stops With Me Is Secondhand Vape Smoke Bad for You? The Truth on the Trend Molekule Don't Be Fooled, E cig Aerosol Is Not Harmless for Kids American Lung Association