Medical Cannabis & DOT Zero‑Tolerance

Some medications that contain THC can genuinely help conditions like chronic pain or seizure disorders. However, when you hold a safety‑sensitive job—driving an 80‑thousand‑pound rig, operating a locomotive, piloting an aircraft—the DOT’s first priority is public safety, not state law. That’s why the federal rule says:

Even if an employee has a state medical‑marijuana card or a doctor’s recommendation, a laboratory‑confirmed THC result is a drug‑test violation. (49 CFR § 40.151 (e)

In plain English: any THC in your system counts as a positive, no matter how or why you took it. Until you complete the Return‑to‑Duty process, you can’t return to DOT‑regulated duties that require full focus and split‑second decisions.