What is a dangerous goods placard?

A dangerous goods placard is a square-on-point (diamond) safety mark displayed on a vehicle or large means of containment that carries dangerous goods. In Canada it is governed by the Transportation of Dangerous Goods Regulations (SOR/2001-286), Part 4. The placard shows the hazard class symbol, colour and, where required, the UN number so first responders can identify the load.

What size must a dangerous goods placard be in Canada?

Under the TDG Regulations a placard must be at least 250 mm × 250 mm, displayed square-on-point (as a diamond). Reduced-size labels (100 mm) are used on smaller means of containment such as drums and boxes, but vehicle and bulk placards use the full 250 mm size.

Where do dangerous goods placards go on a truck?

On a large means of containment (road vehicle, trailer, tank), a placard is generally required on each side and each end — four placards in total — so the hazard is visible from any direction. Confirm placement and the specific marks for your shipment against the current TDG Regulations and your shipping document.

What are the 9 classes of dangerous goods?

The TDG Regulations define nine classes: Class 1 Explosives, Class 2 Gases, Class 3 Flammable Liquids, Class 4 Flammable Solids, Class 5 Oxidizing Substances and Organic Peroxides, Class 6 Toxic and Infectious Substances, Class 7 Radioactive Materials, Class 8 Corrosives, and Class 9 Miscellaneous Products. Each class has its own placard colour and symbol.

Canadian TDG Guide

Dangerous Goods Placards Canada

Q: When are dangerous goods placards required?

Placarding is generally required when the quantity of dangerous goods in a road vehicle exceeds 500 kg gross, but several classes (for example certain explosives, toxic gases and radioactive materials) require placards at any quantity. Always verify the threshold for your specific class and shipment in the TDG Regulations before you ship.

The 9 hazard classes, the 250 mm placard size, where placards go on the vehicle, and the 500 kg threshold — built to the Transportation of Dangerous Goods Regulations.

Last Verified: June 2026 · Based on the TDG Regulations (SOR/2001-286), Part 4

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Dangerous Goods Placards — Quick Facts

Regulation: Transportation of Dangerous Goods Regulations (SOR/2001-286), Part 4 — Dangerous Goods Safety Marks
Minimum size: 250 mm × 250 mm, displayed square-on-point (diamond)
Placement: generally on each side and each end of a large means of containment (4 placards)
Threshold: generally required above 500 kg gross — but some classes require placards at any quantity
Classes: 9 hazard classes, each with its own colour and symbol

The 9 Classes of Dangerous Goods

Every dangerous goods placard maps to one of the nine classes set out in the TDG Regulations. The class determines the colour, symbol and class number that must appear on the placard. Confirm the correct class for your shipment on your shipping document and against the current TDG Regulations before you order.

Class	Hazard	Placard Colour
Class 1	Explosives	Orange
Class 2	Gases	Green / Red / White
Class 3	Flammable Liquids	Red
Class 4	Flammable Solids	Red / White
Class 5	Oxidizers & Organic Peroxides	Yellow / Red
Class 6	Toxic & Infectious Substances	White
Class 7	Radioactive Materials	Yellow / White
Class 8	Corrosives	Black / White
Class 9	Miscellaneous Products	White / Black

Size, Placement & When Placards Are Required

A placard must be at least 250 mm × 250 mm and displayed square-on-point. On a large means of containment — a road vehicle, trailer or tank — a placard is generally required on each side and each end, so four placards are typical. Placards must stay durable and legible for the whole trip, which is why they are produced on weather-resistant outdoor vinyl.

Placarding generally applies once the quantity of dangerous goods in a road vehicle exceeds 500 kg gross. Several classes — including certain explosives, toxic gases and radioactive materials — require placards at any quantity. The 500 kg threshold is a starting point, not a guarantee: always verify the rule for your specific class and shipment in the TDG Regulations.

Important: placard, class and quantity requirements depend on what you are shipping. This page is general guidance built to the TDG Regulations — it is not a substitute for the regulation itself or advice from your dangerous-goods consultant. Confirm your safety marks against the current TDG Regulations before shipping.

TDG Regulations (SOR/2001-286), Part 4