• UK domestic dangerous-goods rules are almost entirely aligned with ADR.
• Major international differences concern ADR tanker marking and IMDG requirements for sea transport.
• IMDG covers packaging, labelling, placarding, marking, stowage, segregation, handling, training and emergency response.
• IMDG transport documents and related information must be retained for at least 3 months.

7.1 MARKING OF TANKERS UNDER ADR

• International tank vehicles over 1,000 litres display plain orange plates front and rear and orange Kemler plates on each side.
• Kemler plates show the hazard identification number above and the 4-digit UN substance identification number below.
• An 'X' before the hazard number indicates a dangerous reaction with water.
• Appropriate hazard-class placards are displayed at the rear and on both sides.
• For a single substance, Kemler plates may be displayed at the front and rear instead of on the tank sides, with appropriate placards.

7.2 IMDG MARKING REQUIREMENTS

• Tank containers, freight containers and unaccompanied semi-trailers require hazard placards on all four sides and the proper shipping name on both sides.
• Vehicles require placards on both sides and at the rear.
• Tank vehicles and vehicles carrying a single packaged commodity also display the proper shipping name on both sides.
• The environmentally hazardous substance mark is also required where applicable.
• Limited Quantity consignments use the relevant Limited Quantity placards.
• For sea legs, IMDG requirements take priority over ADR marking requirements.