[JURIST] The Colorado Supreme Court [official website] on Monday unanimously affirmed [opinion, PDF] a lower court decision that employers’ zero tolerance drug policies are not pre-empted by Colorado’s legalization of medical marijuana. The court held that an employee can legally be discharged for consuming marijuana off-duty, as a plain meaning reading of the state’s lawful off duty activities statute implies that “lawful” is intended to protect only those activities that are permissible under both state and federal law. The opinion emphasizes that “employees who engage in an activity, such as medical marijuana use, that is permitted by state law but unlawful under federal law are not protected by the statute.” While the decision grants employers the ability to impose zero-tolerance policies, it does not require it. Colorado law permits employers to implement drug policies of their choosing, with many employers opting to eliminate THC from pre-employment drug screens.

The legalization of medical marijuana [JURIST backgrounder] has gained much support in recent years, and to date, has seen the drug fully or partially legalized by 21 states and the District of Columbia. However, marijuana remains illegal under federal law, creating conflicts. In early March a bipartisan group of three US Senators introduced a bill [JURIST report] that would reclassify marijuana as a Schedule II drug, which would loosen governmental regulation, and notably, allow states to enact their own medical marijuana statutes without federal interference. A few days later, an identical companion bill was introduced [JURIST report] in the Us House of Representatives.