What Is ADR?
ADR stands for the "Agreement concerning the International Carriage of Dangerous Goods by Road". It was signed in Geneva in 1957 under the United Nations Economic Commission for Europe (UNECE) and is today applied by a large number of countries, including all of Europe. Türkiye acceded to the agreement in 2010. ADR brings the classification, packaging and labelling of dangerous goods, vehicle and tank equipment, driver training and transport documentation together in a single rulebook. Its purpose is simple: at no point in the journey should a dangerous load pose an uncontrolled risk to people or the environment.
The Nine Hazard Classes
ADR divides dangerous goods into nine main classes:
- Class 1: Explosive substances and articles
- Class 2: Gases (compressed, liquefied or dissolved)
- Class 3: Flammable liquids (most fuel transport falls into this class)
- Class 4: Flammable solids, substances liable to spontaneous combustion, and substances which emit flammable gases in contact with water
- Class 5: Oxidising substances and organic peroxides
- Class 6: Toxic and infectious substances
- Class 7: Radioactive material
- Class 8: Corrosive substances
- Class 9: Miscellaneous dangerous substances and articles (for example lithium batteries and environmentally hazardous substances)
Every substance is assigned a four-digit UN number; the orange plates on the transport unit display this number together with the hazard identification number.
What Does It Require on the Tanker and Trailer Side?
ADR-compliant transport is not just a matter of driver certificates and paperwork; the vehicle, and above all the tank itself, must be approved:
- Tank code and type approval: Every ADR tanker is built to a tank code matched to the substance group it will carry. The code defines shell material, design pressure, filling and discharge openings and safety fittings, and the tank receives type approval.
- Vehicle categories: Tractor-tanker combinations carrying flammable liquids are approved as FL vehicles, other tank vehicles as AT; EX/II and EX/III categories exist for explosives.
- Electrical and static safety: Earthing (grounding) connections, explosion-protected electrical installations, a master switch and a battery isolator are mandatory.
- Safety equipment: Flame arresters, overfill prevention systems, emergency shut-off valves, fire extinguishers and written instructions (emergency cards) must be carried.
- Periodic inspection: The tank shell and its equipment undergo intermediate and periodic tests, including leakproofness and hydraulic pressure tests; without a valid approval certificate no dangerous goods may be loaded.
- Drivers and operators: Drivers must hold an ADR training certificate, and operators must appoint a dangerous goods safety adviser.
Why It Matters
A dangerous load carried outside ADR rules carries not only the risk of fire, poisoning or environmental damage but also severe administrative penalties. Thanks to standardised tank design, labelling and training, emergency crews in different countries recognise and handle the same load under the same rules. This is why ADR is one of the fundamental design inputs for international tanker and trailer manufacturing.
Barlas Trailer manufactures and repairs tankers and trailers built to ADR requirements.