"There's just an incredible amount of gray right now" about how marijuana legalization affects employers, said Sandra Hagen Solin of the Northern Colorado Legislative Alliance, a coalition of chambers of commerce.
Police departments are especially worried. Officers take oaths to protect all laws, state and federal. In this case, pot is still prohibited under federal law.
The Seattle police department is reviewing its policies on drug use by officers or prospective officers, spokesman Sgt. Sean Whitcomb said, adding that it's unlikely off-duty officers will be allowed to use pot. The department might ease its requirement that applicants not have used marijuana in the previous three years.
The Denver police department is reviewing Colorado's marijuana law, which goes into effect in January. The department has no immediate plans to change employment practices, spokesman John White said.
"Marijuana is still illegal at the federal level, so officers would not under any scenario be allowed to use marijuana," White said. White wasn't sure about pre-employment marijuana use.
Other employers, especially those with federal contracts, are concerned what the new laws mean for them. One group of Colorado businesses has pleaded for clarity in a letter to the White House, which hasn't said if it would sue to block the law.
"The uncertainly created will cause havoc for our members and hamper their efforts to maintain drug-free worksites," wrote Mark Latimer, head of the Rocky Mountain chapter of Associated Builders and Contractors.
The havoc Latimer refers to is confusion over a law passed with cigarette smokers in mind. Colorado's Lawful Off-Duty Activities law says workers can't be dismissed for legal behavior off the clock. A case pending in a state appeals court could settle the question.
The case involves Brandon Coats, a telephone operator for Dish Network. Paralyzed in a teenage car crash, he's also been a medical marijuana patient in Colorado since 2009. Coats was fired in 2010 for failing a company drug test, though his employer didn't claim he was ever impaired on the job.
Coats sued to get his job back, but a trial court dismissed his claim in 2011. The judge agreed with Dish Network that medical marijuana use isn't a "lawful activity" covered by the law. Coats appealed, and the state Court of Appeals has agreed to hear the case but hasn't set a date.
According to the National Conference of State Legislatures, more than half the states have laws that protect workers who smoke cigarettes off the clock. Colorado's law extends to all legal activities, though Washington state doesn't have a similar statute.
"If you're doing it at home and it's not illegal and it's not impairing your work performance, you should be protected," said Coats' lawyer, Michael Evans.
Some employers are required by law to conduct drug testing, including in industries regulated by the U.S. Departments of Transportation, Energy and Defense. In other cases, companies or agencies that receive federal grants or contracts, including universities that get money from the Department of Education and police agencies that obtain grants from the Department of Justice, are required to maintain drug-free workplaces.
One of Washington's biggest private employers, The Boeing Co., generally requires drug tests before employment, upon reasonable suspicion or after accidents. The Washington measure won't change any of that, said company spokeswoman Cathy Rudolph. "The safety and integrity of our operations, products and services is paramount," she said in an email.
For companies like Boeing without random or regular drug testing, it's not entirely clear how such policies can be enforced.
Some lawyers are encouraging companies to take stock of their drug policies. "This is a good time for employers to revisit their policies and make sure they're still consistent with what they want to do, and to talk with their employees about what the policies are," said Mark Berry, an employment lawyer.
Red Robin Gourmet Burgers, a Denver-based chain with locations in the two states, has no plans to revisit its drug policy. Spokesman Kevin Caulfield said the policy already covers legal drugs, such as prescription medication. Marijuana would be treated the same, he said.
"If a drug is legal, as long as it's not abused or misused, it would not be something covered by the policy," Caulfield said.
Find Kristen Wyatt at http://www.twitter.com/APkristenwyatt
Johnson reported from Seattle and can be reached at http://www.twitter.com/GeneAPSeattle