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Transportation of Dangerous Goods study materials
Transportation of Dangerous Goods study resources

Transportation of Dangerous Goods: Marks, Labels, and Placards

Transportation of Dangerous Goods · Work through your exam, one topic at a time.

All guide sections

Marks, Labels, and Placards

Marks, labels, and placards

This domain tests safety marks: what must appear on a package, a small means of containment, a large means, and a transport unit. Expect label-versus-placard questions, UN number placement, subsidiary hazards, and removal of outdated marks.

Core rules

  • Labels go on packages and small means of containment. They show the primary hazard class and any subsidiary hazard.
  • Placards go on large means of containment and transport units, such as tanks, trailers, and containers, when the class and quantity require them. A placard is larger than a label and is intended to warn from a distance.
  • UN numbers identify the substance. They appear on the means of containment or transport unit as required, and must match the shipping document.
  • Marks and labels must be visible, legible, and located so they are not obscured by doors, fittings, or cargo.
  • Do not display a label or placard for a hazard the goods do not have. Remove or cover old marks before reusing a container for different goods.
  • Orientation arrows are required for certain liquid packages; they are handling marks, not hazard labels.

Worked example

A 200 L drum of a Class 3, PG II liquid is loaded singly into a van. The drum is a small means of containment, so it needs the Class 3 label and the applicable UN number mark, not a placard on the drum. The van is a transport unit; whether it needs a placard depends on the quantity and the placarding threshold for Class 3. The driver cannot rely on the drum label alone to decide placarding.

Traps

  • Placarding a single small package.
  • Using a label where a placard is required on a tank or trailer.
  • Forgetting subsidiary labels, such as toxic or corrosive, when the classification requires them.
  • Leaving old placards on a trailer after unloading.
  • Placing marks where they are hidden by the tailgate or covered by straps.

Exam focus

Separate the questions: what is the means of containment, what is its size, what class and quantity are present, and does the rule require a label, a placard, or both? Then check the UN number and document match.