With California law allowing recreational marijuana (Prop. 64), employers are weighing whether to change drug testing policies. The most frequent employee question since Prop. 64 passed is, “Am I now protected against drug testing on my job?” The answer is “No, but…”: Prop. 64 specifically allows employers to ban marijuana use and impairment in the workplace, even when use is during nonworking hours or for medical reasons. In 2008, California’s Supreme Court ruled employers are not required to accommodate employees’ off-duty use of medical marijuana.

Still, groups are working toward legislation limiting drug testing, and unlike alcohol there is currently no scientific measurement for marijuana impairment. A strict rule terminating employees who test positive is hard to apply equally and may be impractical for retaining today’s workforce.

PROBLEMS WITH DRUG TESTING FOR MARIJUANA: – Invasion of privacy without an overriding interest (like safety) requires a case-by-case weighing of pros and cons. – A positive test does not measure job performance or impairment — it only indicates possible ingestion at some point in the past (up to 30 days), and drug screens have roughly a 10% fail rate. – Challenges can arise from faulty or discriminatory testing procedures (e.g., allowing an employee believed to be under the influence to drive to the testing facility).

Employers still have a duty to provide a safe workplace and can use it to create and enforce reasonable safety policies. Options include: (1) adopt a drug-free workplace policy emphasizing federal law (required for government contractors) and wait for the law to develop; (2) revise the Injury & Illness Prevention Program (IIPP) to extend existing alcohol/prescription drug-testing policies to marijuana; (3) update handbook policies addressing attendance, disruptive behavior, mistakes and low productivity; (4) assemble existing policies or create a new workplace-impairment policy that goes beyond “fitness for duty.” Whichever option is chosen, employers should limit drug testing to well-defined circumstances, provide a checklist and reporting procedure in IIPP supervisor training, disseminate impairment policies, and communicate that it is impairment — not off-duty use — that is measured and grounds for discipline.

Originally distributed as a PDF bulletin. View the original PDF.