Are "Drug-Free" Workplace Standards Discriminatory?

8/2/17:  Does requiring a drug-free workplace violate anti-discrimination laws?  Maybe. In Massachusetts, an employee who was a registered medical marijuana user was fired for failing her employer’s drug test.  According to the Massachusetts Supreme Judicial Court, that employee can proceed in state court with a disability discrimination claim.  An article by Lisa Nagele-Piazza, SHRM-SCP, J.D. published by the Society for Human Resource Management (SHRM) explains the case and its possible challenges for anti-discrimination compliance.