A Coming Medical Marijuana Battle in Colorado?

With more medical-marijuana dispensaries than Starbucks outlets, Denver has emerged as the per capita frontrunner for curative ganja. As more residents partake of doctor-prescribed pot, however, questions are emerging about where the line is between an employee's right to use medical marijuana and an employer's right to a drug-free office.

Employers, of course, don't need to accommodate a worker who shows up stoned. But can someone who legally tokes on his own time, and whose performance isn't hurt, be fired for failing a drug test? "We're in uncharted territory," says Vance Knapp, a Denver employment lawyer who expects the issue to be tested in the courts soon.

So far, judges in California, Washington, Montana, and Oregon have sided with employers. But because Colorado's medical-marijuana laws are in its constitution, not just statutes, legal experts give the edge in any test case to employees. That could mean a breakthrough victory for users, swinging momentum their way and giving pro-patient lawyers in other states much-needed—if nonbinding—precedent.