5.1 Vehicle, Tank, and Container Placarding (ADR Chapter 5.3)

Vehicle, Tank, and Container Placarding (ADR Chapter 5.3)

Purpose and Technical Specifications of ADR Placards

While package labels under ADR Chapter 5.2 alert warehouse handlers and loaders to chemical hazards at close range, ADR Chapter 5.3 hazard placards provide an immediate visual warning to emergency responders and road users from a safe distance. In a traffic collision or rollover incident, emergency crews must instantly identify the nature of the cargo before approaching the vehicle.

Under ADR 5.3.1.7, placards are enlarged reproductions of the hazard warning labels prescribed in ADR 5.2.2 for the substances carried. They must satisfy strict dimensional and design standards:

• Shape and Orientation: An equilateral square set at an angle of 45° (a diamond).
• Minimum Dimensions: At least 250 mm by 250 mm along each outer edge.
• Border Line: An inner line parallel to the outer edge, positioned exactly 12.5 mm inside the border. Unspecified features follow the prescribed proportions. The Class 7 placard has its own model and a line 5 mm inside the edge.
• Symbols and Text: The hazard symbol, class number, and color scheme must correspond precisely to the standard package label for that hazard class. The hazard class or division number in the bottom corner must be at least 25 mm high.
• Weather Resistance: Under ADR 5.3.1.1.1, placards must be capable of withstanding open-air exposure, wind, and rain without substantial detachment or fading throughout the entire transport operation.

A package label is normally 100 × 100 mm; a standard placard is at least 250 × 250 mm. They perform different identification roles.

Which Transport Units and Cargo Units Carry Placards?

Placarding obligations under ADR Part 5 depend directly on the containment type (tank, bulk, container, or package) and the specific hazard class.

1. Tank-Vehicles, Battery-Vehicles, and Demountable Tanks (ADR 5.3.1.4.1)

Road tankers, battery-vehicles carrying compressed gases, and vehicles transporting demountable tanks must display hazard placards on:

• Both sides of the vehicle (or tank).
• The rear of the vehicle.

2. Multi-Compartment Tank-Vehicles (ADR 5.3.1.4.1)

When a road tanker contains multiple compartments carrying different dangerous goods (for example, UN 1202 diesel fuel, UN 1203 petrol, and UN 1223 kerosene, or an acid in one compartment and an alkali in another):

• Compartment Sides: Placards corresponding to the substance inside each compartment must be displayed on both sides of that specific compartment.
• Rear of Vehicle: All applicable placards representing every distinct substance carried across all compartments must be displayed on the rear of the vehicle.
• Uniform Hazard Simplification: If all compartments contain substances that require the identical hazard placard (for instance, three different grades of flammable fuel that all require the Class 3 placard), only one set of placards on both sides and one placard on the rear is required, rather than repeating the same placard side-by-side.

3. Tank-Containers, Portable Tanks, MEGCs, and Bulk Containers (ADR 5.3.1.2)

Intermodal units such as tank-containers, portable tanks, Multiple-Element Gas Containers (MEGCs), and bulk containers (BK1, BK2, BK3) must display hazard placards on all four sides (both lateral sides and both ends). If a tank-container is loaded onto a flatbed or skeletal trailer and its placards are not clearly visible from outside the vehicle, identical placards must also be affixed to both sides and to the rear of the carrying vehicle.

4. MEMUs — Mobile Explosives Manufacturing Units (ADR 5.3.1.4.3)

MEMUs carrying bulk components (such as ammonium nitrate emulsion Class 5.1 and solid fuels) used to manufacture commercial blasting explosives on site must display placards on both sides and at the rear corresponding to each substance carried.

5. Transport Units Carrying Packaged Goods (ADR 5.3.1.5)

A fundamental principle tested in the ADR examination is that ordinary vehicles carrying packages of classes other than 1 and 7 do not ordinarily display vehicle placards; a freight container on the vehicle has its own placarding requirements. Ordinary box trucks, curtain-siders, and flatbeds carry only plain orange-coloured plates at the front and rear (ADR 5.3.2.1.1).

There are only two critical exceptions where vehicles carrying packages MUST display full vehicle placards:

• Class 1 (Explosives): Vehicles carrying packages of Class 1 substances or articles must display Class 1 placards on both sides and at the rear of the vehicle. The division number (e.g., 1.1, 1.2, 1.3, 1.4, 1.5, or 1.6) must be shown. Compatibility groups are omitted if goods of different compatibility groups are carried together. Division 1.4, Compatibility Group S packages are exempt from vehicle placarding.
• Class 7 (Radioactive Material): Vehicles transporting packages, overpacks, or freight containers containing radioactive substances must display enlarged Class 7 placards (Model No. 7D), subject to the excepted-package provisions, on both sides and at the rear of the vehicle.

Placard Removal and Covering of Cleaned Units (ADR 5.3.1.1.5)

Under ADR 5.3.1.1.5, empty, uncleaned tanks, battery-vehicles, MEGCs, tank-containers, and bulk containers that contain residues or hazardous vapours must remain placarded and marked exactly as when carrying a full load.

Placards and orange plates must be removed, completely covered, or reversed only when:

1. The tank or compartment has been thoroughly cleaned, emptied, washed, and degassed.
2. In the case of toxic or radioactive goods, the interior and exterior surfaces have been decontaminated.
3. The unit no longer presents any chemical, toxic, flammable, or environmental hazard.

Displaying placards or orange plates on a clean, empty vehicle or a vehicle carrying non-dangerous cargo is a legal violation under ADR roadside enforcement regulations and can lead to immediate fines.

Summary: ADR Placarding Rules Comparison Matrix

Source check: 17 October 2026 — ADR 2025, English text published by the Slovak Ministry of Transport, 5.3.1.