Mississippians voted last year to legalize medical marijuana, but the tension between federal and state law presents new challenges for contractors, especially those working in multiple states and jurisdictions. The Occupational Safety and Health Act’s general duty clause requires contractors to maintain a safe job site and work environment “free from recognized hazards that are … likely to cause death or serious physical harm,” but it can be difficult to determine when an employee may be impaired and a drug test is warranted. While some states require employee accommodation for medical use, other states that have legalized medical marijuana do not. It is important for businesses to develop a well-defined drug policy to minimize the risk of harm to persons and property and decrease the likelihood that drug testing and disciplinary action arising from marijuana intoxication will create liability for adverse employment decisions. Once developed, a contractor should administer a consistent drug testing program.