There is no obligation to retain shipping documents for shipments that are exempted from dangerous goods procedures as being non-regulated, such as lithium batteries shipped under Section II.
However, some State May have a variation. It is therefore necessary to double check DGR 2.8.1 for any State Variation which might say otherwise. Furthermore, there May be an instance where a shipment which should have been handled as dangerous was by error handling as exempted. If such an incident surfaces, a retroactive investigation would take place. It is therefore advisable to have a record taken of all such non-regulated shipments.