49 CFR § 225.18 - Alcohol or drug involvement.
(a) In preparing Form FRA F 6180.54, “Rail Equipment Accident/Incident Report,” under this part, the railroad shall make such specific inquiry as may be reasonable under the circumstances into the possible involvement of alcohol or drug use or impairment in such accident or incident. If the railroad comes into possession of any information whatsoever, whether or not confirmed, concerning alleged alcohol or drug use or impairment by an employee who was involved in, or arguably could be said to have been involved in, the accident/incident, the railroad shall report such alleged use or impairment as provided in the current FRA Guide. If the railroad is in possession of such information but does not believe that alcohol or drug impairment was the primary or contributing cause of the accident/incident, then the railroad shall include in the narrative statement of such report a brief explanation of the basis of such determination.
(b) For any train accident within the requirement for post-accident testing under § 219.201 of this chapter, the railroad shall append to the Form FRA F 6180.54, “Rail Equipment Accident/Incident Report,” any report required by 49 CFR 219.209(b) (pertaining to failure to obtain samples for post-accident toxicological testing).
(d) In providing information required by this section, a railroad shall not disclose any information concerning use of controlled substances determined by the railroad's Medical Review Officer to have been consistent with 49 CFR 219.103.