All about vapes what's in them, how do they work, and more Philip Morris International Just like footprints you leave behind, smoke and vape leave traces too. On your clothes. In your home. In the air your family breathes. The smell may fade, but the harmful residue Does Vaping Smell? and How to Tell if Someone Is Vaping Ultra Liquid Labs 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.