Colorado employers are anxiously awaiting an appellate court decision on whether properly registered medical marijuana users in the state may have a public policy wrongful discharge cause of action if they are discharged for a positive cannabis test result under their employers' drug and alcohol abuse programs. To date, every court in the country has rejected wrongful discharge claims by such medical marijuana users - most recently the Western District of Michigan in Casias v. Wal-Mart Stores, Inc., Case No. 1:10-CV-781 (W.D. Mich. Feb. 11, 2011). The reasoning of Casias should comfort Colorado employers, as Michigan's medical marijuana law is similar to Colorado's.

In Casias, a good employee, who tested negative for marijuana when hired in 2004, tested positive when corporate policy required him to undergo testing in 2009, after a workplace injury. Before the second test, the employee had qualified for a registry card under Michigan's recently-enacted Medical Marihuana Act and had begun using marijuana away from work. When he was tested in 2009, he showed his medical marijuana card to the drug testing staff and his shift manager. Wal-Mart's corporate office decided to terminate his employment, based on a violation of policy. When the employee was advised of his discharge, he reiterated his possession of a medical marijuana card and was told that Wal-Mart's policy made no exception for medical marijuana use.

The federal court in Casias, interpreting the Michigan Medical Marihuana Act, dismissed the employee's public policy claim. The Court found that the Act merely provided a potential defense to a criminal prosecution or other adverse action by the state, and did not regulate private employment or create private employment rights. The Court found nothing in the Michigan Act creating a special class of civil protections for medical marijuana users. In the course of reaching this conclusion, the Court noted that the Michigan law did not, and could not, change the fact that marijuana use is a federal felony, 21 U.S.C. § 812; 21 U.S.C. § 841(a)(1).

One section of Michigan's Act, similar to Colorado's version of the law, provides that the Act does not require an employer "to accommodate the ingestion of marihuana in any workplace or any employee working while under the influence of marihuana." M.C.L. § 333.26427(c)(2). The plaintiff unsuccessfully argued that this language, by negative implication, permitted the use of medical marijuana away from the workplace.