Secondhand vape exposure: Risks and side effects If someone smokes outside, do they bring thirdhand smoke indoors with them? Thirdhand Smoke Resource Center Do cigars cause thirdhand smoke? Thirdhand Smoke Resource Center 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 Smart vapes' with games could lure youths, experts say Los Angeles Times