SALEM — An attorney for Columbia Forest Products Inc. argued before the Oregon Supreme Court that voters who approved the Oregon Medical Marijuana Act never intended to force companies to let employees come to work with the drug in their systems.

But Philip Lebenbaum, an attorney representing a mill worker who was fired after failing several drug tests, told the justices Monday that his client’s medical condition left him legally disabled, requiring his employer to make reasonable accommodations for him in the workplace under the Oregonians with Disabilities Law.

The case pits an employer’s right to ensure a safe workplace against a worker’s right in Oregon to use marijuana at home to treat pain. It started in 2001, when Robert Washburn was fired from the company’s mill in Klamath Falls after several failed urine tests.

Washburn had a state-issued card allowing him to use marijuana to ease neck and muscle pain that disrupted his sleep. Washburn, who said he used the drug at home, sued the company, claiming it should have made an allowance for his disability.

A circuit court dismissed the lawsuit, citing a provision in the state medical marijuana law that employers don’t have to “accommodate the medical use of marijuana in the workplace.”

But the state Court of Appeals disagreed, setting the stage for a high-court review. A key question is whether “in the workplace” includes employees using it at home and having it in their systems when they arrive at work.

Voters approved physician-approved medical marijuana use in 1998. Since then, more than 11,000 residents have received state-issued medical marijuana registry cards.

The company argued that state law does not provide workers a blanket exemption allowing them to come to work under the influence.

Portland truckmaker Freightliner, Boise-based grocer WinCo Foods Inc. and Portland roofing material manufacturer CertainTeed Corp. filed briefs on Columbia’s behalf. All three say they found workers in “safety sensitive” positions carrying state-issued medical marijuana cards. Columbia and Freightliner also argue that their government contracts require them to enforce federal drug-free workplace laws.

Justices aren’t expected to issue a ruling on the case until 2006.

Their decision likely would override an interpretation by the Oregon Bureau of Labor & Industries. The agency has said employers might have to make reasonable accommodations for medical-marijuana cardholders with qualified disabilities, including changing their shifts so they don’t show up to work at times they’re likely to be impaired.

In June, a bill that would have exempted employers from making accommodations for medical marijuana, regardless of where it was used, passed the Oregon House of Representatives 39-20.

The bill failed to make it out of a Senate committee.