Early research says secondhand smoke from vaping may not be as bad as cigarettes, but it's still not harmless. https: fox59.com news national world does vaping cause secondhand smoke doctors explain the side effects Secondhand exposure from vaping marijuana: Concentrations, emissions, and exposures determined using both research grade and low cost monitors ScienceDirect Juul study shows secondhand vaping emissions are less toxic than cigarette smoke Secondhand Smoke and Electronic Cigarette Aerosol Resources US EPA