4. Without prejudice to the generality of the provisions contained in these Regulations—
(a)the operator of a container, tank container, tank wagon or wagon which is being used for the carriage of dangerous goods shall take all reasonable steps to ensure that such of the requirements specified in any of the approved documents as are relevant to that container, tank container, tank wagon or wagon are complied with in relation thereto;
(b)the operator of any train which is being used for the carriage of dangerous goods in any container, tank container, tank wagon or wagon and each infrastructure controller upon whose railway the goods are carried, shall take all reasonable steps to ensure that such of the requirements specified in any of the approved documents as are relevant to that container, tank container, tank wagon or wagon are complied with in relation thereto;
(c)any person who designs, manufactures, imports, supplies, modifies, repairs, examines, tests, certifies or fills a tank which is intended to be, or is being, used for the carriage of dangerous goods shall ensure, insofar as they are matters within his control, that such of the requirements in the Approved Tank Requirements as are relevant to that tank are complied with in relation thereto.