(a) Within or outside of an HTUA, rail hazardous materials shipper transferring to carrier. Except as provided in paragraph (g) of this section, at each location within or outside of an HTUA, a rail hazardous materials shipper transferring custody of a rail car containing one or more of the categories and quantities of rail security-sensitive materials to a freight railroad carrier must do the following:

(1) Physically inspect the rail car before loading for signs of tampering, including closures and seals; other signs that the security of the car may have been compromised; and suspicious items or items that do not belong, including the presence of an improvised explosive device.

(2) Keep the rail car in a rail secure area from the time the security inspection required by paragraph (a)(1) of this section or by 49 CFR 173.31(d), whichever occurs first, until the freight railroad carrier takes physical custody of the rail car.

(3) Document the transfer of custody to the railroad carrier in hard copy or electronically.

(b) Within or outside of an HTUA, carrier receiving from a rail hazardous materials shipper. At each location within or outside of an HTUA where a freight railroad carrier receives from a rail hazardous materials shipper custody of a rail car containing one or more of the categories and quantities of rail security-sensitive materials, the freight railroad carrier must document the transfer in hard copy or electronically and perform the required security inspection in accordance with 49 CFR 174.9.

(c) Within an HTUA, carrier transferring to carrier. Within an HTUA, whenever a freight railroad carrier transfers a rail car containing one or more of the categories and quantities of rail security-sensitive materials to another freight railroad carrier, each freight railroad carrier must adopt and carry out procedures to ensure that the rail car is not left unattended at any time during the physical transfer of custody. These procedures must include the receiving freight railroad carrier performing the required security inspection in accordance with 49 CFR 174.9. Both the transferring and the receiving railroad carrier must document the transfer of custody in hard copy or electronically.

(d) Outside of an HTUA, carrier transferring to carrier. Outside an HTUA, whenever a freight railroad carrier transfers a rail car containing one or more of the categories and quantities of rail security-sensitive materials to another freight railroad carrier, and the rail car containing this hazardous material may subsequently enter an HTUA, each freight railroad carrier must adopt and carry out procedures to ensure that the rail car is not left unattended at any time during the physical transfer of custody. These procedures must include the receiving railroad carrier performing the required security inspection in accordance with 49 CFR 174.9. Both the transferring and the receiving railroad carrier must document the transfer of custody in hard copy or electronically.

(e) Within an HTUA, carrier transferring to rail hazardous materials receiver. A freight railroad carrier delivering a rail car containing one or more of the categories and quantities of rail security-sensitive materials to a rail hazardous materials receiver located within an HTUA must not leave the rail car unattended in a non-secure area until the rail hazardous materials receiver accepts custody of the rail car. Both the railroad carrier and the rail hazardous materials receiver must document the transfer of custody in hard copy or electronically.

(f) Within an HTUA, rail hazardous materials receiver receiving from carrier. Except as provided in paragraph (j) of this section, a rail hazardous materials receiver located within an HTUA that receives a rail car containing one or more of the categories and quantities of rail security-sensitive materials from a freight railroad carrier must—

(1) Ensure that the rail hazardous materials receiver or railroad carrier maintains positive control of the rail car during the physical transfer of custody of the rail car;

(2) Keep the rail car in a rail secure area until the car is unloaded; and

(3) Document the transfer of custody from the railroad carrier in hard copy or electronically.

(g) Within or outside of an HTUA, rail hazardous materials receiver rejecting car. This section does not apply to a rail hazardous materials receiver that does not routinely offer, prepare, or load for transportation by rail one or more of the categories and quantities of rail security-sensitive materials. If such a receiver rejects and returns a rail car containing one or more of the categories and quantities of rail security-sensitive materials to the originating offeror or shipper, the requirements of this section do not apply to the receiver. The requirements of this section do apply to any railroad carrier to which the receiver transfers custody of the rail car.

(h) Document retention. Covered entities must maintain the documents required under this section for at least 60 calendar days and make them available to TSA upon request.

(i) Rail secure area. The rail hazardous materials shipper and the rail hazardous materials receiver must use physical security measures to ensure that no unauthorized individual gains access to the rail secure area.

(j) Exemption for rail hazardous materials receivers. A rail hazardous materials receiver located within an HTUA may request from TSA an exemption from some or all of the requirements of this section if the receiver demonstrates that the potential risk from its activities is insufficient to warrant compliance with this section. TSA will consider all relevant circumstances, including the following:

(1) The amounts and types of all hazardous materials received.

(2) The geography of the area surrounding the receiver's facility.

(3) Proximity to entities that may be attractive targets, including other businesses, housing, schools, and hospitals.

(4) Any information regarding threats to the facility.

(5) Other circumstances that indicate the potential risk of the receiver's facility does not warrant compliance with this section.