In a victory for employers in the long-running medical marijuana battle, the Oregon Supreme Court ruled that companies can fire workers who test positive for marijuana use even if they have a medical marijuana card.

In a 5-2 decision in Emerald Steel Fabricators, Inc. v. Bureau of Labor and Industries last week, the court said that the state law voters approved in 1998 – which shields possession, growth and distribution of medical marijuana from state criminal liability – does not override a federal law that classifies marijuana as illegal.

The decision means companies consistently can enforce zero-tolerance drug policies – and strikes a blow against medical marijuana advocates. Emerald Steel brings Oregon in line with both California and Washington rulings that say employers have no duty to accommodate medical marijuana use. For the record, Oregon is one of 14 states where inhaling for medical reasons is legal. (Illinois has legislation pending, and last month, South Dakota election officials certified for the November ballot a measure that would exempt authorized patients possessing up to an ounce of marijuana or six plants from state criminal penalties. In 2006, the state's voters narrowly rejected a similar proposal.)

In 2003, Eugene's Emerald Steel Fabricators hired Anthony Scevers as a temporary steel press operator. The company didn't ask the staffing company that had Scevers on its books if Scevers had passed a drug test, and told him he'd need to pass a drug test if he wanted full-time work. After a few months of good work, Scevers asked his boss about a permanent job, revealing he smoked pot because of nausea, stomach cramps, and vomiting. (Scevers never smoked at work and there was no evidence it ever impaired him in the workplace.) His boss didn't attempt to see if any alternative work might be suitable, but instead told Scevers that full-time work wasn't an option — and ended his temporary assignment. Scevers charged discrimination under state disability law, filing a complaint with the Oregon Bureau of Labor and Industries.

The labor commissioner's office ruled in Scevers' favor, saying the employer hadn't accomodated his disability and ordering Emerald Steel in 2005 to pay Scevers $20,000 in lost wages and benefits and $25,000 for emotional suffering. (The judgment remained in bond pending appeal.)

In June 2008, the Oregon Court of Appeals agreed with the agency, though the decision focused more on workplace procedures about "interactive process" in accommodating disabilities than it did on the issue of drug use in the workplace. But last week the Oregon Supreme Court ruled that medical marijuana was still considered an illegal drug under federal law – and that therefore no employer could be forced to accommodate its use because state disability discrimination law specifically says illegal drug users are not protected by the statute.

From the majority opinion: "Because employee did not take marijuana under supervision of a licensed health care professional and because the authorization to use marijuana [found in state law] is unenforceable, it follows that employee was engaged in the illegal use of drugs." The decision went on to make employer's obligations very clear: "Under Oregon's employment discrimination laws, employers are not required to accommodate an employee's use of medical marijuana."

Associated Oregon Industries, the state's largest business-lobbying organization, praised the ruling in a statement. "The decision now means that employers can be assured that they can consistently enforce their zero-tolerance drug policies," AOI said. The group had filed a friend-of-the-court brief in support of Emerald Industries.