According to the results of a new study published in the Journal of Analytical Toxicology, by researchers at the John Hopkins School of Medicine, one-third of individuals who vaped cannabidiol (CBD)-dominant cannabis tested positive for tetrahydrocannabinol (THC) using a urine-based drug test. In this study, participants vaped CBD samples, some of which contained trace amounts of THC, the main psychoactive ingredient found in the cannabis plant.
The study participants included three men and three women who had agreed to ingest (either by vaping or taking capsules) 100% pure CBD or cannabis, with the dominant active ingredient of CBD. The cannabis samples given to participants contained 10.5% CBD and 0.39% THC, with placebo versions of both forms of CBD also provided to participants. Several sessions of the study involved giving participants active and placebo versions of the two products, with some sessions where participants received pure CBD capsules and placebo cannabis sample containing no THC.
Dr. Ryan Vandrey, the principal investigator of the study, pointed out in his interview with Consumer Reports that the THC level of 0.39% in the CBD-dominant cannabis sample is only slightly higher than the 0.30% allowed in hemp-derived CBD products, which are currently legal. However, other products currently sold, including products labeled high-CBD/low-THC, could potentially have levels comparable to those tested by the study, according to the researcher.
One-third of the participants who vaped the high CBD/low THC product tested positive for THC using urine drug testing, after a single episode of vaping. Although the amount of THC used in this product is 0.09% higher than the legal THC limit in hemp-derived CBD, Dr. Vandrey had suggested that individuals who use more than one dose of hemp-derived CBD per day could test positive for THC due to its cumulative effect in the body. “The packaging of those products most commonly suggests using them two times a day,” Dr. Vandrey said.
Overall, the study results suggest the possibility that individuals who use CBD could still test positive for THC. “[The study] confirms that even if you are exposed to the low levels of THC in commonly produced cannabidiol products, there is a risk of a positive result in employer drug screens… There have been several cases highlighted in the media in which people using CBD products tested positive for THC. So there can be significant legal ramifications,” said Ziva Cooper, director of research for the Cannabis Research Initiative at the University of California.
