Substance Use Testing
There is no federal privacy statute directly governing employer substance testing. The ADA excludes current illegal drug use (a drug test is not a medical exam) but protects alcoholics who are qualified. Federal law mandates testing for safety-sensitive roles (aviation, rail, trucking) and preempts contrary state law. Cannabis legalization adds complexity.
No federal privacy statute directly governs employer testing for drugs, alcohol, or tobacco. For public employees, Fourth Amendment case law applies. The ADA excludes current illegal drug use (a drug test is not a medical exam) but treats a qualified alcoholic as protected; histories of addiction must be scrutinized for job-relatedness and business necessity.
| Setting | General rule |
|---|---|
| Preemployment | Generally allowed if not designed to identify legal drug use or addiction |
| Allowed as a condition of continued employment on specific facts and inferences | |
| Routine testing | Allowed if employees notified at hire, unless prohibited by state/local law |
| Post-accident | Allowed on reasonable suspicion the employee was under the influence |
| Sometimes required, sometimes prohibited; acceptable for narrowly defined jobs in highly regulated industries or critical to safety/security |
Federal law mandates testing for safety-sensitive roles (aviation, railroading, trucking) and preempts state laws that would limit it. Because cannabis is federally prohibited, employees in these industries must follow federal rules even where state law legalizes cannabis - and fewer than half of legalizing states protect employees who test positive.