Secondhand and thirdhand vape exposure is a serious issue, especially when children are involved. Unlike firsthand vaping, which directly introduces harmful chemicals into the lungs, secondhand exposure affects those nearby, Should I Be Concerned About Secondhand Vaping? Chemicals Tobacco Smoke, Vaping, and Asthma AAFA.org Sitting somewhere when a cloud of cotton candy vapor washes over you? If you can smell the sweet scent of a vape, that's not a great sign.