Does e-cigarette consumption cause passive vaping? The creators reflect on the possible consequences of using electronic cigarettes in the indoor habitat. Another important idea that the author discusses is that electronic cigarettes use passive vaping. They mentioned that e-cigarettes contain liquids with and without nicotine. Usually, the e-cigarettes have propanediol that causes fume during exhalation. On the other hand, initially, cigarettes were created by direct evaporation without a combustion process.