Detection of delta-9-tetrahydrocannabinol (THC) in oral fluid, blood and urine following oral consumption of low-content THC hemp oil
Hayley, AC, Downey, LA, Hansen, G, Dowell, A, Savins, D, Buchta, R, Catubig, R, Houlden, R & Stough, CKK 2018, 'Detection of delta-9-tetrahydrocannabinol (THC) in oral fluid, blood and urine following oral consumption of low-content THC hemp oil', Forensic Science International, vol. 284, pp. 101-106.
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Hemp-derivative (Cannabis sativa L.) food products containing trace levels of Δ-9-tetrahydrocannabinol (THC) are proposed for consumption in Australia and New Zealand; however, it is unclear whether use of these products will negatively affect existing drug screening protocols. This double-blind, within-subjects, cross-over trial assessed 35 adults (17 male; 18 female), aged 22–52 years [Mean = 30.7, Standard Deviation (S.D) ± 7.6]. Low dose THC oil [5 mL bearer sesame oil containing 10 mg/kg THC (0.046 mg THC per 5 mL dose)]; high dose THC oil [5 mL bearer sesame oil containing 20 mg/kg THC (0.092 mg THC per 5 mL dose)]; and a placebo oil (THC negative) was consumed during a three-week protocol. The Securetec Drugwipe® II Twin device assessed THC presence (cut-off 20 ng/mL) in oral fluid at baseline, at 5, 30, 60, 120 and 240 min post-treatment. Blood was drawn at baseline, 30, 120 and 240 min post-treatment, and urine at baseline and 240 min post-treatment. No THC was detected in oral fluid, blood or urine samples at any time-point following consumption of the low or high THC dose. Trace concentrations of 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid (THCa) were detected in blood 4-h after consumption of the high THC treatment (M = 0.0001 mg/L) and in urine at 4-h post consumption of both low and high THC treatments (M = 0.0001 mg/L and 0.0004 mg/L, respectively). Consumption of low-content THC oil does not result in positive biological assessments. It is therefore highly unlikely that ingestion of products containing these levels of THC will negatively impact existing region-specific drug driving enforcement protocols.