Illinois has legalized the sale and use of marijuana for personal and recreational use, leaving employers to wonder what sort of testing will still be allowed. While employers are still allowed to monitor the use of marijuana while on the job and maintain a drug-free workplace, it is important to become familiar with the Cannabis Regulation Tax Act (CRTA). The act identifies and allows employers to adopt certain cannabis policies relating to use, consumption, storage and impairment to further protect employee safety. The most difficult part of maintaining a drug-free workplace will be when determining whether an employee is impaired or under the influence of cannabis. When any action is taken against an employee, the employee must be provided a reasonable opportunity to challenge the basis of an employee’s determination.