As marijuana legalization spreads from municipality to municipality and state to state, employers watching this wave of legislation to end marijuana prohibition have good reason to wonder about the future of their employment policies.

And in questionable workplace situations that involve medical marijuana, employers might be confused about what they are and are not required to accommodate under the Americans with Disabilities Act.

The annual Disability Management Employer Coalition's Annual Conference in Las Vegas included a panel discussion Aug. 12, “Cautionary Tales: The Impact of Legalized Marijuana on the Workplace.” DMEC executive director Terri Rhodes noted that any employer with a federal contract will want to pay special attention to this issue.

“What's really driving this issue is the federal contract component,” Rhodes said. “Employers that have federal contracts must comply with federal law, and the federal government is still saying that the use of marijuana is illegal.

“In order to get reimbursement through these contracts,” Rhodes said, “employers need to comply with the regulations and to maintain a drug-free workplace. If an employee does test positive for marijuana, and they do have a medical marijuana card in a state where that's approved, employers have to deal with that issue.”

The inability to accurately test for marijuana impairment compounds this problem; in states that have passed marijuana-related impairment laws, such as the driving-while-impaired law in Colorado, much debate has centered around where to set the legal blood limit for THC (the psychoactive ingredient in marijuana).

Because THC is not water-soluble, it remains in the body and bloodstream for up to 30 days after consumption – so a medical marijuana user with a chronic pain condition who medicates regularly throughout the day likely will have to have a much higher blood-THC content than a casual user, but the casual user likely will be more impaired from a physical and mental standpoint than the chronic one.

“Under the ADA, there is no obligation to accommodate marijuana use,” said Danielle Urban, an employment attorney with the Fisher & Phillips law firm in Denver, “even if someone has a disability and a health care professional has said the employee might benefit from the medical use of marijuana. As an employer, you are free to have a zero-tolerance policy, with some exceptions, such as states like Arizona and Minnesota.”

Minnesota's law states that as long as employees aren't using or impaired at work, they are protected from losing their jobs for testing positive for marijuana if they are a medical marijuana patient; Arizona's law states that as long as medical marijuana patients are not impaired at work or employed in a safety position, they are protected from losing their jobs from testing positive for marijuana use.

Read more: Determining impairment …

In general, there are no readily available, inexpensive methods to test for impairment.

Although there are some computer-based assessment programs that can help employers test for impairment, where the employee “takes a baseline test when he or she first starts working,” Urban explained. “These tests are fairly sophisticated and require having someone on staff who is properly trained to administer the test and evaluate results – and very few employers can really afford to have someone like that on staff.”

However, employers must be cognizant of the fact that employees approaching them with medical marijuana questions may have a condition that is protected under the ADA, even if their marijuana use to treat that condition is not protected.

“Employers shouldn't simply say, 'I can't accommodate you,' especially if the employee has come to them with this issue before violating company policy with a positive drug test,” Urban said. “In most states, employers are not required to accommodate marijuana use, but they must recognize that the employee may have a condition that is protected under the ADA. It is up to the employee to engage in the interactive process with the employer to address the need for accommodation in a way that not only accommodates the employee but also does not become an undue hardship on the employer.”

As an example of an ideal situation, say an employee suffers from chronic nausea and is using medical marijuana to treat it, and the employee approaches the employer and discloses the condition and the marijuana use. If the employer is not comfortable with the employee's marijuana use, then the employee and employer should work together to find effective alternatives to medical marijuana the employer is willing to accommodate.

Perhaps the employee is more nauseated at certain times of the day, and the employer can work to adjust the employee's schedule so he or she is not required to be at work during those hours. Employers can also provide additional leave days for the employee to use when the condition flares up, and employers can even suggest and accommodate other alternative treatment methods that have been shown to treat pain and nausea, such as acupuncture.

There are also compounds that synthesize the medically useful components of marijuana without the psychoactive components, such as Marinol, which are available with a prescription from a doctor, but employers also should be aware that medical marijuana users say that these compounds are not as effective as marijuana for treating their conditions.

“It's simple in theory,” Urban said, “but it's very complicated in real life, because disabilities are a complicated issue for employers. No two disabilities are the same.”

Rhodes adds that when an employee does test positive for marijuana in a zero-tolerance workplace, there are usually several steps the employer takes before moving to terminate the employee.

“Most employers have an option where they would offer drug counseling, rehabilitation and employee assistance programs, and possibly a last-chance agreement,” she said. “And while the ADA does not condone illegal drug use, it does require employers to have discussions and not just carte blanche fire somebody because they have a medical condition and are treating it with marijuana.”