All employers are required under OSHA to provide a safe place to work. The elimination of the influence of drugs/alcohol at the workplace is essential in meeting this legal obligation. Further, federal contractors are required to have a drug free workplace. Some people think that if marijuana is permitted for medical or recreational use an employer cannot restrict the use. However, everyone seems to understand that you cannot show up for work drunk or you cannot work if you are taking any medication that will interfere with your performance.