Passive Inhalation of Marijuana

Marijuana (THC) initial drug screen tests performed at PeaceHealth Laboratories are conducted using a 20 ng/mL or 50 ng/mL screening threshold (cutoff). A positive marijuana drug test result that is solely due to reasonable, accidental exposure to marijuana sidestream smoke (passive inhalation) will not occur when the initial screen test is coupled with our quantitative gas chromatography/mass spectrometry (GC/MS) confirmation procedure for a specific THC metabolite (carboxy-THC). The THC-20 test with GC/MS confirmation provides increased sensitivity for detection of cannabinoid use while eliminating the possibility of positive results from passive inhalation.