Among 1,504 cannabinoid-positive workplace urine tests, 25% contained delta-8 THC metabolites — and 11% were exclusively delta-8 users, highlighting a new challenge for workplace drug testing.
Read this if you use delta-8 THC products and are subject to workplace drug testing — standard tests will flag delta-8 the same as regular cannabis.
What the researchers found
Delta-8 THC has gone from obscure cannabinoid to widespread consumer product almost overnight, and this study shows it's already creating a significant presence in workplace drug testing. The researchers analyzed 1,504 urine specimens that had tested positive on initial cannabinoid immunoassay screening, using advanced LC-MS-MS to distinguish between delta-8 and delta-9 THC metabolites.
The results split into three clear groups. The majority — 76% — were delta-9 THC dominant (traditional cannabis). Another 11% were delta-8 THC dominant, indicating people using exclusively or primarily delta-8 products. The remaining 13% showed a mixture of both, suggesting use of both delta-8 and conventional cannabis products.
Altogether, about 1 in 4 positive workplace tests contained delta-8 THC metabolites. This is remarkable given that delta-8 was virtually unknown to consumers just a few years ago.
A practical finding for drug testing programs: delta-8 and delta-9 THC metabolites reached similar urine concentrations (median 150 vs 187 ng/mL), supporting the use of similar cutoffs and decision rules for both. Standard immunoassay tests can't distinguish between them — both trigger a positive cannabinoid result. Only confirmatory testing with mass spectrometry can identify which type of THC was used.
For employees in states where delta-8 is legal but delta-9 isn't, this creates a legal gray zone: their drug test may come back positive despite using what they believe is a legal product.
Why it matters
Workplace drug testing programs weren't designed to distinguish between delta-8 and delta-9 THC. With delta-8 now showing up in a quarter of positive tests, employers and medical review officers face a practical problem: a positive test may reflect use of a product that's legal in the employee's state. This data forces a rethinking of how workplace cannabinoid testing is interpreted and what constitutes a 'positive' result in the delta-8 era.
The numbers in context
1,504 cannabinoid-positive urine specimens analyzed. 964 (76%) delta-9 dominant. 164 (11%) delta-8 dominant. 376 (13%) mixed. Combined delta-8 prevalence: ~25% of positive tests. Median concentrations: delta-9 THC-COOH 187 ng/mL, delta-8 THC-COOH 150 ng/mL (similar, supporting comparable cutoffs).
How the study worked
Observational study analyzing 1,504 urine specimens with positive cannabinoid immunoassay screening results from workplace drug testing. Specimens were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS-MS) quantifying 15 cannabinoid analytes after hydrolysis, allowing differentiation between delta-8 and delta-9 THC metabolites. Specimens were categorized as delta-9 dominant (>90% delta-9), delta-8 dominant (>90% delta-8), or mixed.
Who was studied
N=1,504 urine specimens from workplace drug testing in the US.
What this study cannot tell us
The 1,504 specimens were already cannabinoid-positive on immunoassay, so this study measures delta-8 prevalence among positive tests, not among all workers tested. No information on the legal status of delta-8 in each employee's jurisdiction. No clinical or impairment data — can't determine whether delta-8 users were impaired at work. Single laboratory dataset — geographic distribution of specimens not described. The rapid evolution of the delta-8 market means prevalence may have changed since the study period.
How to read the evidence
Observational forensic laboratory study with a large sample of workplace drug testing specimens. The analytical methods are rigorous (LC-MS-MS), and the prevalence data is clear. However, this represents one laboratory's data and the delta-8 market changes rapidly.
When this study was published
Published in 2023. Delta-8 prevalence in workplace testing is likely still evolving as the market grows and state regulations shift.
The bigger picture
This is the workplace testing counterpart to the delta-8 scoping review (RTHC-00096). While that review mapped the broad regulatory chaos around delta-8, this study quantifies its real-world impact on drug testing programs. Together with RTHC-00082 (workplace cannabis policies) and RTHC-00081 (Swedish workplace testing), these studies document a drug testing infrastructure struggling to keep up with rapidly changing cannabis products and laws.
Replication
Not stated in abstract.
Funding
Not reported in abstract.
Conflicts of interest
Not reported in abstract.
Questions still open
- Should workplace drug testing programs adopt confirmatory methods that distinguish delta-8 from delta-9? How should employers handle positive tests in states where delta-8 is legal? Is delta-8 THC as impairing as delta-9 THC at equivalent doses — and does workplace safety require the same response to both? Should delta-8 products carry warnings about drug testing implications?
Read the original research
Prevalence of ∆8-tetrahydrocannabinol carboxylic acid in workplace drug testing.
Journal of analytical toxicology, 47(8), 719-725
The Journal of Analytical Toxicology is a reputable journal focusing on the analysis of toxic substances in biological samples.
Citation
Vikingsson, Svante; Hart, E Dale; Winecker, Ruth E; Cone, Edward J; Kuntz, David J; Clark, Michael; Jacques, Martin; Hayes, Eugene D; Flegel, Ronald R. (2023). Prevalence of ∆8-tetrahydrocannabinol carboxylic acid in workplace drug testing.. Journal of analytical toxicology, 47(8), 719-725. https://doi.org/10.1093/jat/bkad068
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