Researchers affiliated with the University of Utah published results of a study on the potential for non-THC cannabinoids to demonstrate cross-reactivity with urine tests for THC metabolites in the March 24, 2020 issue of the The Journal of Applied Laboratory Medicine, finding that cannabinol (CBN), a cannabinoid that demonstrates significant structural similarity to tetrahydrocannabinol, can trigger false positives in two commonly used commercial immunoassays (drug tests), the EMIT II Plus and Microgenics MultiGent.
CBN has been reported as early as 1990 to be a primary degradant of THC, especially when raw cannabis containing THC is exposed to heat and light. As hemp agriculture expands, CBN has been targeted as a lucrative novel cannabinoid for farmers, with studies suggesting that CBN has significant sedative qualities rivaling Valium and other diazepam compound medications. Studies in mice models also suggest that CBN also has appetite stimulation properties, and antibacterial properties have also been identified.
It took 5 times more CBN than the cutoff concentration of THC to generate a false positive with the Emit II Plus and 20 times more CBN than THC to produce a false positive on the Microgenics MultiGent test.