49 CFR § 655.46
Return to duty following refusal to submit to a test, verified positive drug test result and/or breath alcohol test result of 0.04 or greater
November 18, 2020
Where a covered employee refuses to submit to a test, has a verified positive drug test result, and/or has a confirmed alcohol test result of 0.04 or greater, the employer, before returning the employee to duty to perform a safety-sensitive function, shall follow the procedures outlined in 49 CFR Part 40.