(a) General. The purpose of this part is to protect the occupational safety and health of certain employees who are exposed to occupational dangers while in the cab of the locomotive. This part prescribes minimum Federal safety and health standards for certain locomotive cab occupants. This part does not restrict a railroad or railroad contractor from adopting and enforcing additional or more stringent requirements.

(b) Subpart B of this part. The purpose of subpart B is to protect the occupational safety and health of employees whose predominant noise exposure occurs in the locomotive cab. Subpart B prescribes minimum Federal safety and health noise standards for locomotive cab occupants.

(c) Subpart C of this part. The purpose of subpart C is to protect the occupational safety and health of train employees and certain other employees in the cab of the locomotive of a freight train that is transporting a poison inhalation hazard (PIH) material that, if released due to a railroad accident/incident, would pose an inhalation hazard to the occupants. In particular, subpart C is intended to protect these employees from the risk of exposure to the material while they are located in, or during escape from, the locomotive cab.