Marijuana activists aren’t the only people keeping a close eye on what the Trump administration does with federal drug policies. So is business.

Some business groups would like to see the White House issue new rules on marijuana use by workers and what employers should and shouldn't allow, especially regarding medicinal use.

The legalization of marijuana, recreational, medical, or both, in more than 30 states has created a host of complicated issues for businesses because it is still illegal under federal law. Employers don't know if marijuana use is allowed under the Americans with Disabilities Act, how to handle workers who live in states that have legalized marijuana although the business might be in a different state, or how to handle workers' compensation claims.

“We’d like to see [the Department of Labor] issue something just for clarity’s sake,” said a source for one major Washington trade association speaking on background, adding that they aren't pushing for any particular direction. They just want the administration to say where the lines are drawn.

Asked if they were mulling any rulemaking or other guidance, a Labor Department spokesman referred all questions to the Justice Department, which declined to comment. But another Justice Department source who wasn’t authorized to speak for the record told the Washington Examiner that “rumblings” were heard inside the department that the administration was looking into the issue.

It's an area where the administration has already made substantial moves, just not ones that legalization advocates welcomed. Attorney General Jeff Sessions has been an outspoken critic of decriminalization.

In January, he rolled back an Obama-era policy that prevented federal authorities from prosecuting the pot trade in states where it has been legalized. Sessions said the move was necessary to “to disrupt criminal organizations, tackle the growing drug crisis, and thwart violent crime across our country.”

Much harder to read is what the administration will do for companies that aren't in that business but may have workers who use pot. Despite state laws legalizing pot, marijuana remains illegal under the Controlled Substances Act, a Nixon-era law passed long before the recent state legalizations. Courts have been struggling to figure out how federal workplace laws fit into the split.

“Most case law does not recognize marijuana use as something that is covered by the ADA, but there are circuit court cases that are pushing back on that,” said Daniel Shortt, a Seattle-based attorney and founder of the University of Washington’s Cannabis Law and Policy Project. Other areas involving workplace law are even grayer, he said.

The 9th Circuit Court of Appeals rejected a 2012 case against the city of Costa Mesa, Calif., in which the plaintiffs argued the city’s ban on marijuana dispensaries violated the ADA. The court said the ADA did not require the city to provide services that were illegal under the Controlled Substances Act.

More recently in a 2015 case called Steele v. Stallion Rockies, a U.S. District Court judge for the District of Colorado rejected a claim by a worker who said that his firing for medical marijuana use violated the ADA, but on the limited grounds that he didn’t prove he was disabled.

Other issues include whether a worker fired for medical marijuana use is entitled to workers' compensation. Courts in Maine have said no, while their New Mexico counterparts have said yes.

Federal courts complicate matters even when federal law isn’t at issue. In a 2012 Michigan case called Casias v. Walmart, a worker was found to have been legally fired for violating the employer’s drug policy despite a state medical marijuana law prohibiting “disciplinary action” against “qualifying patients.” The 6th Circuit Court of Appeals ruled on the narrow grounds that the state law didn’t regulate private employment.

Another area that is not clear are the legal marijuana dispensaries themselves, Shortt notes. Can a dispensary worker sue for lost wages under federal law like any other worker, even if the business isn't legal under federal law? Such cases are bound to crop up as the industry grows and becomes more profitable. “There’s going to be more of the pie to cut up,” Shortt noted.

In a 2016 study for the National Association of Attorneys General Training Institute’s journal, Program Counsel Francesca Liquori noted that while recent cases have given employment lawyers some guidelines, “much is still unclear.” Can employing a medical marijuana user get an employer in trouble under the Occupational Health and Safety Act? What if an employee uses medical marijuana while away under the Family and Medical Leave Act?

“If an employer in a non-legalization state employs an individual who lives in a neighboring state which has legalized medical marijuana … what law controls?” Liquori asked. The same month the study came out, she left the attorneys general group to join the Justice Department. While business lobbyists would like to see some signal from the administration on what to do, marijuana activists are dreading the prospect.

“We have already seen a largely hostile reaction from this administration. For us, the best-case scenario is for the federal government to retain a ‘hands off’ approach,” said Justin Strekal, political director for the National Organization to Reform Marijuana Laws. “We are focusing on strengthening laws at the state level.”

Shortt disagrees, saying the administration doesn’t have to release any official rules. “A lot can be done with a simple memorandum when an industry exists in a gray area. ... Even though we do have a hostile administration, clarity is still good.”