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More than a third of private employers do some type of drug testing of their employees, but the landscape is changing. Marijuana is now legal in two states. It's approved for medical use in nearly half the states. In spite of that, many employers are sticking with their anti-drug policies. And as NPR's Yuki Noguchi reports, those policies are now being tested in court.
YUKI NOGUCHI, BYLINE: A car accident crushed Brandon Coat's upper spine at age 16, leaving him wheelchair-bound. His muscles still spasm, disrupting sleep and causing pain.
BRANDON COATS: If I'm out in public, it's really embarrassing. It's always uncomfortable. When I smoke marijuana, it almost completely alleviates it.
NOGUCHI: More, he says, than other prescriptions. He smokes at his Denver home at night and says, he was never high when answering customer calls at Dish Network.
COATS: You know, they always had percentages of where people were, and I was always in the top 5 percent, and I was really good at my job.
NOGUCHI: But a couple weeks after he was called in for random drug test four years ago, he became persona non grata.
COATS: I went to go open the door. My card wouldn't open up the door anymore.
NOGUCHI: Michael Evans is the lawyer representing Coats, whose case is going before the Colorado Supreme Court.
MICHAEL EVANS: You know, we're not pushing for use at work. We're pushing for - if you're in the privacy of your own home, and you're registered with the state and abiding by the constitutional amendment, is that an OK reason for your employer to fire you?
NOGUCHI: Since Coats sued Dish, Colorado has legalized pot, making it a regulated substance like alcohol. But as Evans notes, workplaces still treat pot and test for it in a manner very different from alcohol.
EVANS: The test that Dish did was a saliva test. And all the test was concerned about is THC present - yes or no?
NOGUCHI: And therein lies the problem. The standard urine test most commonly used in employer drug testing measures the presence of the psychoactive compound THC in pot for days or even weeks. So unlike a breathalyzer for alcohol, a person need not be high in order to test positive.
Barry Sample is director science and technology for Quest Diagnostics, which conducts millions of drug tests. He says, there may eventually be similar impairment tests for pot.
BARRY SAMPLE: It might be possible at some point. There's some interesting technology that's developing.
NOGUCHI: But for now, businesses are neither changing nor relaxing the way they test for pot. And that raises some questions for businesses, says Deborah Keary, vice president at the Society for Human Resource Management.
DEBORAH KEARY: If you had a martini on Saturday night or you smoked pot on Saturday night, but your fine on Monday morning, how is Saturday night the employer's business? So I really think that they're going to have to change the way they do testing and find a way to define impairment.
NOGUCHI: And at least in Colorado, the legalization of pot is putting employers in even murkier legal territory. Under state law, employers can prohibit the use of marijuana at work, but another state law called the Lawful Activity Statute prohibits an employer from discharging an employee for engaging in lawful activity off the premises of the employer during non-working hours.
LARA MAKINEN: And so that's where everything really gets muddied up.
NOGUCHI: Lara Makinen is legislative affairs director in Colorado for the Society for Human Resource Management. She says, employers are getting a very mixed message.
MAKINEN: We're being told keep your policy as it is, but proceed with caution because if people are fired like Mr. Coats, we probably will see lawsuits.
NOGUCHI: Dish Network, the defendant in the Brandon Coates case, declined to comment. But the company said, it is sticking by its drug-free policy, which, it says, is consistent with the federal law which still considers pot an illegal substance. Oral arguments for Coats' case are said to begin in late September. Yuki Noguchi, NPR News, Washington.