Interpretation of Workplace Tests for Cannabinoids

Summary & key facts

This article explains how U.S. workplace drug tests look for marijuana. Most programs test urine for an inactive THC breakdown product, using a quick screen followed by a lab confirmation. A confirmed positive means that metabolite was present, but it does not prove someone was high or that they used very recently. The paper also explains that many synthetic cannabinoids won’t show up on these tests, some prescription THC products will, and that state legalization has made workplace rules more complicated.

Key facts:

• Most workplace drug tests use urine and look for an inactive THC metabolite called THC‑COOH, which is a breakdown product and does not cause intoxication.
• Testing is usually two steps: a rapid screening test first, and if that is positive a more specific laboratory confirmation test is done.
• A confirmed positive urine test does not prove impairment or recent use. It only shows the metabolite is present.
• In heavy or chronic marijuana users, the THC metabolite can stay in urine for weeks or even months after last use.
• Most illicit synthetic cannabinoids (for example products sold as K2 or Spice) usually do not trigger a positive test for THC metabolites because their chemistry is different from THC.
• Some prescription products that contain actual THC, like dronabinol (Marinol), will cause a positive urine test, while other synthetic drugs that are chemically different may not.
• Urine is the most common testing sample now, but blood, saliva (oral fluid), and hair are sometimes used or may be used more in the future.
• Federal workplace testing treats any marijuana use as unacceptable under federal law and does not accept state medical marijuana as a legitimate reason; private employers can set different policies.

Topics

Alcohol Consumption and Health Effects Cannabis and Cannabinoid Research Forensic Toxicology and Drug Analysis

Categories

Health Sciences Medicine Pharmacology

Tags

Blood testing Cannabinoid Cannabis Drug Intensive care medicine Internal medicine Medicine Pharmacology Psychiatry Receptor Substance Abuse Detection Urine

Substances

Cannabis

Conditions & symptoms

Substance abuse disorder Addiction or harmful habbits