The legal gray area surrounding the legalization of marijuana in Colorado and Washington state, not to mention the 20 states that allow medical marijuana, has put many non-cannabis related businesses in a tricky situation. For example, can an employer terminate employment for a failed drug test if the marijuana was purchased legally? What if the employee has a prescription for the drug? 

Employers can still prohibit marijuana use

Given the prevalence of drug testing in the United States, this conundrum is particularly pertinent. The answer, from a legal perspective at least, appears to be relatively simple: Legal weed can still get you fired.

As long as federal law prohibits marijuana use, employers appear to be in the clear if they wish to maintain a marijuana-free work force. This prohibition is not simply about turning up on the job high, either. Because drug tests can detect canabis in the bloodstream up to 30 days after it was consumed — and long after any high has faded — marijuana users argue that the situation is unfair. Here's how one activist explained the situation to ABC7 Denver:

"No business would ever fire an employee simply because they had a couple beers over the weekend or a cocktail after work," said marijuana advocate Mason Tvert. "So there's really no logical reason why an employee should be fired just for using marijuana over the weekend — which is a far less harmful substance." But Amendment 64 makes it clear that the law will not, "... affect the ability of employers to institute policies restricting the use of marijuana by employees."
Is marijuana use a safety issue?

Many employers, however, defend their right to prohibit marijuana use, especially in positions where employees are responsible for public safety. The American Camp Association (ACA), for example, recently issued guidelines on legal marijuana, reminding campers that even when marijuana is medically prescribed, it is still a drug that can impair an individual's ability to function. Here's a sampling of the ACA's specific tips:

  1. Medical marijuana is considered a "Schedule I" controlled substance under federal law. As an employer, generally you can refuse to hire, terminate an employee, or refuse to allow a camper to attend who is currently using marijuana, whether for medical reasons or otherwise.
  2. If you are inclined to accommodate the use of medical marijuana on or off your premises by one of your staff, consider the consequences. Even if you choose to allow such use, consider that there is a well-documented body of research identifying that use of marijuana impairs an individual’s ability to function — and that impairment would logically extend to many traditional camp activities (for example, driving vehicles or running a zip line or challenge course) and the supervision of co-workers and campers.
Banks refuse to do business with growers

It's not just employers that are asking questions about legal marijuana. The New York Times reports that many banks are refusing to do business with marijuana growers and sellers fearing, in part, that federal officials may still take action against the industry and the businesses that serve it. The resulting financial limbo for many cannabis businesses has turned a simple act as paying taxes into a situation that is as surreal as it is deeply risky. From the NYTimes:

When he finishes, he stashes the money in the trunk of his BMW and sets off on an adrenalized drive downtown, darting through traffic and nervously checking to see if anyone is following him. Despite the air of criminality, there is nothing illicit in what Mr. Kunkel is doing. He co-owns five legal medical marijuana dispensaries, and on this day he is heading to the Washington State Department of Revenue to commit the ultimate in law-abiding acts: paying taxes. 
I'll be thinking about Kunkel's challenges the next time I complain about filling out tax forms. We sure do live in interesting times. 

Related on MNN:

What does legal marijuana mean for business?
Can an employer still fire you if you have a prescription for marijuana? Can a bank do business with a grower?