What Is THC (Cannabis)?
What it is
THC (tetrahydrocannabinol) is the main psychoactive component of cannabis. Urine tests detect its metabolite (Δ9-THC-COOH), which persists after use.
Why it matters
THC is the most common drug screened in workplace testing; cut-off typically 50 ng/mL.
Specimen
Urine
Cut-off
50 ng/mL
Interpretation
Positive = THC metabolite (Δ9-THC-COOH) detected above cut-off (presumptive). Negative = below cut-off.
Limitations
Presumptive result — confirm positives by GC-MS/LC-MS. Passively-exposed individuals may rarely screen positive.
Related test: THC (Marijuana) Rapid Test — specimen: Urine
Frequently Asked Questions
What is the THC cut-off? Typically 50 ng/mL for workplace urine screening, aligned with SAMHSA-style thresholds.
Related knowledge
References
- SAMHSA. Mandatory guidelines for federal workplace drug testing programs.
Last reviewed: 2026-09-12