In this legal and social landscape, employers that have operations where medical marijuana laws exist, face increasing exposure for employee lawsuits claiming state law protects their right to use marijuana when they are away from work. However, all state supreme courts having addressed this issue thus far ruled in favor of employers. For example, in a recent decision in Colorado, Coats v. Dish Network LLC, No. 13SC394 (June 15, 2015), the Colorado Supreme Court unanimously upheld Dish Network’s termination of Coats, a quadriplegic worker who suffered from muscle spasms, for testing positive on a drug test allegedly due to his off-duty medical marijuana use.

Similarly, in Casias v. Walmart Stores Inc., No. 11-1227 (6th Circuit, September 19, 2012), an employee at a Walmart store in Michigan allegedly used medical marijuana pursuant to Michigan’s medical marijuana law outside of work to treat chronic pain. After undergoing a drug test, he tested positive for marijuana and Walmart terminated his employment a week later. The employee sued, alleging wrongful discharge in violation of public policy and in violation of the 2008 Michigan Medical Marijuana Act (MMMA). The district court dismissed the wrongful termination action, holding that the MMMA does not regulate private employment. After the employee appealed, the 6th Circuit of Appeals affirmed the lower court’s dismissal, finding “the MMMA does not impose restrictions on private employers….” Similarly, in 2010, the Oregon Supreme Court ruled in Emerald Steel Fabricators Inc. v. Bureau of Labor and Industries that Oregon employers are not required to accommodate the use of federal-defined illegal drugs, including medical marijuana, that are otherwise allowed under state law. Courts in California, Montana and Washington have also found that employers need not accommodate the marijuana usage of their employees.

These cases illustrate a general support for employers’ efforts to maintain a safe and drug-free workplace while also illustrating the potential for tension between an employer’s desire for a safe and productive work environment and what an employee perceives state law might permit or protect, especially during his or her own private time. However, every state’s laws (or lack thereof) regarding marijuana are unique and an employer needs to be cognizant of those that apply where it does business. Nevertheless, no state prohibits an employer from setting its own drug-free workplace policies and in those few states where laws state that an employer cannot discriminate against an employee for his or her status as a medical marijuana program participant (e.g., Arizona, Connecticut, Delaware, Illinois, Maine, Minnesota, Nevada, New York and Rhode Island), no case has yet reached a state’s highest court determining whether an employer must accommodate use, especially for safety-sensitive positions such as mining work.

Therefore, employers are still free to have zero tolerance policies and/or drug-free workplace policies and to test for marijuana use as part of their programs.

Although some state laws are changing, federal law still prohibits the use and sale of marijuana. In fact, it remains a schedule I drug under the federal Controlled Substances Act, which means that under federal law, it lacks any accepted medical use and there is no accepted safety for use in medically supervised treatment. Also, since medical marijuana is still considered an illegal drug under federal law, its use is not protected under the Americans with Disabilities Act.

Further, the federal safety standards that apply to certain employers like mine operators and trucking companies, imposed by federal agencies such as the U.S. Department of Transportation, (DOT), do not provide for the use of marijuana by miners or other employees covered by their regulations. Specifically, the DOT has issued a statement that “the Department of Transportation’s Drug and Alcohol Testing Regulation — 49 CFR Part 40, at 40.151(e) — does not authorize ‘medical marijuana’ under a state law to be a valid medical explanation for a transportation employee’s positive drug test result…It remains unacceptable for any safety-sensitive employee subject to drug testing under the DOT’s drug testing regulations to use marijuana.” Thus, for truck operations that are covered by DOT standards, they are still required to ensure that those who operate trucks and other vehicles are not under the influence.

Mine operators should remember that they still have the prerogative to set their own drug-related work rules, regardless of alleged changes to public opinion. Mine operators should review their current drug testing policies and make necessary changes that clarify to miners their expectations with regards to safety, impairment on the job, the use of marijuana and termination. They should consult with an attorney before distributing these changes to their miners to review policies against their state’s current marijuana laws.

Mine operators should ensure that supervisors and managers are properly trained and educated on any changes made to the drug workplace policies, including what to do when a miner uses medical marijuana prior to coming on his shift or fails a drug test.

Mine operators should communicate expectations to miners regarding the mine’s drug workplace policies, including any changes to written policies. They should also emphasize how important it is to safety, health, and productivity for the mine to remain free from off-duty and on-duty marijuana usage that could lead to marijuana impairment on the job.

Matthew F. Nieman is a shareholder in Jackson Lewis’ Washington, D.C., region office. Linda Otaigbe is an associate in Jackson Lewis’ Washington, D.C., region office.