28. In any proceedings for an offence consisting of a contravention of any of the provisions of these Regulations prior to 1st January 1997 it shall be a defence for the accused to prove that the goods were carried, or in the case of an alleged contravention of regulation 13 intended to be carried, before 1st January 1997 in—
(a)a road tanker in accordance with the Road Traffic (Carriage of Dangerous Substances in Road Tankers and Tank Containers) Regulations 1992(1) as in force immediately before these Regulations came into force; or
(b)in bulk or in packages in accordance with the Road Traffic (Carriage of Dangerous Substances in Packages etc.) Regulations 1992(2) as in force immediately before these Regulations came into force.