Vehicles entering the UK from the contininent carrying hazardous substances or dangerous goods, UK vehicles going on international journeys, and vehicles which are foreign-registered but operating in the UK, operate under the ADR international regulations.

(L'Accord Européen relatif au Transport International des Marchandises Dangereuses par Route (ADR))

The purpose of this agreement is to allow the carriage of dangerous goods freely throughout the countries that are bound by that agreement. As the UK is bound by the agreement there are many vehicles on our roads operating under ADR. British vehicles on international journeys that are carrying dangerous goods will also be operating under the agreement. British vehicles operating on national journeys only are subject to domestic legislation which has been harmonised in most respects with ADR. The agreement allows the carriage of dangerous goods in packages as well as those being moved in bulk.

Drivers of vehicles carrying dangerous goods on ADR operations should be in possession of the following documents.

1. A transport document which gives details of the dangerous substance. There is no laid down format but usually a 'CMR' or similar note is normally used. CMR is an international convention standardising conditions of carriage, documentation for loads and carriers liability which police are not normally concerned with.

2. Information in writing about the nature of the dangers of the substance being carried and the emergency action to be taken (normally in the form of a Tremcard). This information must be available in the languages of all countries of transit.

3. A certificate of approval for vehicles carrying dangerous substances and explosives. Where a vehicle is carrying a tank container the vehicle's domestic test certificate is sufficient.

4. A Vocational Training Certificate (colloquially known as the ADR Certificate in the UK) covering the class of goods that are being carried.

Vehicles that are carrying packaged goods that come within the scope of transport categories 0 to 4 must be labelled with an orange board to the front and an orange board to the rear.

Tankers and tank containers operating under the ADR agreement are required to display orange rectangular reflective plates which bear two sets of numbers.

A tanker carrying a single substance will display these plates front and back. Vehicles carrying tank containers will display these on the sides of the tank container and orange boards will be displayed on the vehicle.

A two or three figure number appears on the upper part of the plate is a hazard identification number sometimes referred to as the "Kemler" code.

Where a vehicle or vehicle and trailer are carrying one substance, one panel should be displayed on the front and one on the rear. Both panels must be clearly visible.

Where a tanker is also pulling a tank trailer, and different substances are being carried on each vehicle, then each must display an ADR panel front and rear.

Vehicles carrying multi-loads in compartments will display plain orange reflective plates front and rear, and the orange ADR information panels must be displayed on each side of each compartment.