Although Arizona’s medical marijuana law does not contain language that expressly provides medical marijuana users the right to sue employers, the federal district court in Arizona has found that such an implied right exists.

In Whitmire v. Wal-Mart Stores, Inc., an employee was subjected to a drug test following a workplace injury. She tested positive for marijuana use and was terminated, despite informing the employer that she was a registered user of medical marijuana. She then sued, and the employer argued that the medical marijuana law does not provide a private right of action. Looking to cases in Connecticut and Delaware, where such a private right of action was implied in the antidiscrimination provisions of their medical marijuana laws, the court similarly found an implied private right of action.

The court then turned to the interaction of the medical marijuana law with the state’s drug testing law. The drug testing law prohibits suit against an employer that has established a drug testing policy and program for actions taken based on the employer’s good faith belief that the employee was impaired on the employer’s premises or during working hours. In this case, the court found that the test results alone were not sufficient to support a good faith belief that she was impaired at work. Rather, proving impairment based on such results is a scientific matter requiring expert testimony, which had not been offered.

This case highlights the difficulty that employers have in navigating the medical marijuana laws. The parameters of such laws are subject to interpretation by courts. Judges have been increasingly willing to find protections for employees. Moreover, as the court’s reference to expert testimony suggests, unlike an alcohol test, a drug test for marijuana does not actually measure impairment. Thus, impairment must be established through other means.