Can You Fail a Drug Test from Secondhand Smoke? Understanding the Facts Are Weed Vape Pens Safe? Does Vaping Weed Smell? (More Terpenes = Stronger Smell) Single vaping episode of cannabis could yield positive results in urine drug tests Harris County DA Sean Teare's office has told local law enforcement his office cant accept simple possession charges for vape pens believed to contain THCciting limits in current lab testing and a Vaping Marijuana Gets You Way, Way Higher Than Smoking It, Study Finds Live Science