Can You Actually Get a Contact High? Green Goods Secondhand Vape Exposure: Effects, Who's at Risk, and More Can You Fail a Drug Test From Second Hand Smoke? US Drug Test Centers US Drug Test Centers How Long Does Marijuana (Weed) Stay in Your System? Secondhand exposure from vaping marijuana: Concentrations, emissions, and exposures determined using both research grade and low cost monitors ScienceDirect Even if an employee only uses marijuana on the weekends, it could still show up on their workplace sponsored drug screen the following week or later. According to some estimates, traces of THC