Medical Marijuana Testing Issues Smolder

By Diane Cadrain Sep 14, 2010
Gary Ross had worked about three days as a systems administrator at a California telecommunications firm when the company withdrew its job offer—not because of Ross’ poor performance, but because he had tested positive for marijuana in a drug screen conducted before he was hired. Ross, an Air Force veteran, used marijuana with a doctor’s permission for an otherwise untreatable pain in his back.

In Oregon, Jane Roe had a similar experience, putting in about eight days as a telephone customer service rep until she tested positive in a pre-employment screen. She used marijuana, again on a doctor’s authority, to treat migraines.

Their employers didn’t claim that Ross and Roe were bungling their jobs. The presence of marijuana in their systems was the sole reason for their terminations. The high courts of California and Oregon backed up those employment decisions. Laws allowing medical marijuana use don’t undercut an employer’s right to dictate drug use standards for their workforces.

Firing medical marijuana users because they have it in their bodies amounts to disability discrimination and a form of wrongful discharge, “compassionate use” advocates claim. They point out that the workplace drug screens in widest use don’t show whether the employee was impaired at work, and they’ve mounted lawsuits that have reached the highest courts of several states.

So far, the courts aren’t buying their claims. But workplace testing issues continue to smolder.

Of all the tests in workplace use, the urine test “is by far the most popular, with the longest track record,” said Dr. Todd Simo, medical director of HireRight, an employment screening management company. It’s also the least costly.

But urine test results aren’t accurate indicators of work performance. “They only show that a person has used marijuana in the prior days or weeks, not whether the person is impaired at the time,” said Scott Michelman, who is representing Joseph Casias, the plaintiff in a workplace medical marijuana case that will go before the high court of Michigan. “Impairment testing would be a big step for business because it would show present impairment on the job.”

“You can’t extrapolate impairment from the presence of [marijuana],” agreed Simo.

If impairment is the information employers seek, experts say that tests of oral fluids are a much more accurate measure.

“Oral fluids come much closer to showing impairment,” said David Martin, a pharmacologist who is the executive director of the Drug and Alcohol Testing Industry Association. “They’re accurate for showing use within recent hours, unlike urine or hair, which only point to use days or weeks ago.”

“The detection window for oral fluid is comparable to the window for a blood test,” added David Black, an attorney with Seattle law firm Jackson Lewis. “The test itself is also less invasive than a blood test.”

So why aren’t more employers using oral fluid tests?

“That’s a question for employers,” said Simo. “Oral fluid tests are gaining in popularity, with results very close in time to ingestion. When a person ingests or smokes [marijuana], it contaminates the oral fluid. A person is positive as soon as they smoke a joint.

“You’re detecting THC contamination—the ‘parent drug’—not the metabolite,” he added.

Oral fluid tests are more expensive than urine tests, but there is savings in that an employer doesn’t have to send employees to an off-site lab.

“It’s done with a swab,” said Simo. “On balance, the expenses even out.”

No Standard for Impairment

Whatever the test, experts on both sides of the medical marijuana issue agree that there is no accepted standard that establishes marijuana impairment, as there is for alcohol.

“In California, the alcohol threshold is .08—if an employee has a blood alcohol content of .01, he’s not impaired, but at .15 he would no longer be an employee,” said the vice president of human resources for a sheet metal fabricating company with 2,000 employees nationwide, including California; he asked not to be identified for this article. “We need something like that for marijuana because basically all we have now is yes or no.”

“We have over 50 years’ experience with the idea that concentration of alcohol above one-tenth of one percent as indication of impairment; this value is universal,” said Martin. “But there is no impairment correlation for marijuana because it’s so dangerous to submit people to testing with it. You have no idea what’s in it—pesticides, fungicides—and there’s too much variability.”

What about dispensing with urine and oral fluid tests and just focusing on impairment?

“Levels of impairment vary from individual to individual,” said Black. “A person might not be impaired even if they have marijuana metabolites in their system. The better practice is not to terminate for impairment because that’s hard to show. It’s better to terminate based on a zero-tolerance policy.”

“If you’re going to look at impairment, the way to review that is easy to do but fraught with uncertainty,” said employment attorney Richard Meneghello of Fisher & Phillips in Portland, Ore. “You observe the employee at work, same as with any other intoxicant—look at slurred speech, glassy eyes, odor and coordination, and big-picture things like attendance, productivity and motivation. Have someone write objective criteria.”

In Meneghello’s experience, seven out of 10 employers would rather look at a drug test result than take this approach. “A handful say ‘live and let live, I don’t want to fire someone because they peed in a cup."

Client confidentiality prevented Meneghello from revealing the identity of employers who take the more lenient approach, but he would say that one was an office setting, one a food service setting and one in graphic design, and that all were in the “the more liberal part” of Oregon.

“It’s okay to accommodate someone. You don’t have to fire someone because they test positive, but it could be risky not to,” he said. “You could be sued for negligence.”

What about the fact that there’s no correlation between a positive test result and impairment?

Meneghello pointed to a 1985 Stanford University study for which airline pilots consumed a low-grade marijuana cigarette before entering a flight simulator involving a stressful scenario. The test resulted in numerous crashes.

The next day, all the pilots said, they felt no residual effects of the drug and had no reservations about flying, but they crashed the simulator again.

“As long as there’s information like that out there, employers aren’t going to be interested in climbing the slippery slope between an employee’s condition within five seconds, 24 hours or two weeks of ingestion,” Meneghello said. “All it takes is one catastrophe.”

Diane Cadrain is an attorney who has been writing about employment law issues for more than 20 years. She is a member of the Human Resource Association of Central Connecticut.


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