(a) An employer shall establish a program that provides for testing for alcohol in the following circumstances: post-accident, reasonable suspicion, random, and return to duty/follow-up. An employer may also conduct pre-employment alcohol testing.

(b) Each employer shall prohibit a covered employee, while having an alcohol concentration of 0.04 or greater, from performing or continuing to perform a safety-sensitive function.

Each employer shall prohibit a covered employee from using alcohol while performing safety-sensitive functions. No employer having actual knowledge that a covered employee is using alcohol while performing safety-sensitive functions shall permit the employee to perform or continue to perform safety-sensitive functions.

(a) General. Each employer shall prohibit a covered employee from using alcohol within 4 hours prior to performing safety-sensitive functions. No employer having actual knowledge that a covered employee has used alcohol within four hours of performing a safety-sensitive function shall permit the employee to perform or continue to perform safety-sensitive functions.

(b) On-call employees. An employer shall prohibit the consumption of alcohol for the specified on-call hours of each covered employee who is on-call. The procedure shall include:

(1) The opportunity for the covered employee to acknowledge the use of alcohol at the time he or she is called to report to duty and the inability to perform his or her safety-sensitive function.

(2) The requirement that the covered employee take an alcohol test, if the covered employee has acknowledged the use of alcohol, but claims ability to perform his or her safety-sensitive function.

Each employer shall prohibit alcohol use by any covered employee required to take a post-accident alcohol test under § 655.44 for eight hours following the accident or until he or she undergoes a post-accident alcohol test, whichever occurs first.

(a) No employer shall permit a covered employee tested under the provisions of subpart E of this part who is found to have an alcohol concentration of 0.02 or greater but less than 0.04 to perform or continue to perform safety-sensitive functions, until:

(1) The employee's alcohol concentration measures less than 0.02; or

(2) The start of the employee's next regularly scheduled duty period, but not less than eight hours following administration of the test.

(b) Except as provided in paragraph (a) of this section, no employer shall take any action under this part against an employee based solely on test results showing an alcohol concentration less than 0.04. This does not prohibit an employer with authority independent of this part from taking any action otherwise consistent with law.