A transport placard is not a poster: its size is written into the regulation. A carrier stopped with a placard that is too small can have the load refused. Here are the dimensions Canadian law asks for, and the ones the configurator sets on its own.
What the regulation calls for
The figures below come from Part 4 of the Transportation of Dangerous Goods Regulations (SOR/2001-286).
| What it is | Required dimension | Size to pick here |
|---|---|---|
| Large means of containment placard — the class 1 to 9 diamonds | 250 mm per side | 14 in. (356 mm) — a diamond with 250 mm sides fits inside a 353.6 mm square |
| Small means of containment label — 6.2, fissile, radioactive materials | 100 × 100 mm | 4 in. (102 mm) |
| Orange UN number panel | 300 × 120 mm | custom size, 300 × 120 mm (11.8 × 4.7 in.) |
| Limited quantity and excepted quantity marks | 100 × 100 mm | 4 in. (102 mm) |
| Marine pollutant and elevated temperature marks | 250 mm per side | 10 in. (254 mm) |
| UN3373 mark | 50 mm per side | 2 in. (51 mm) |
| Orientation arrows, fumigation, lithium batteries | no dimension in the Canadian regulation | your call |
Why 14 in. and not 10 in.
This is the question we get asked most. The 250 mm per side rule is about the side of the diamond. A diamond is a square standing on its point: for each of its sides to measure 250 mm, it has to be printed inside a square of 353.6 mm — that is 13.9 in. We round up to 14 in. (356 mm), and the placard comes out at the right size.
A placard ordered at 10 in. (254 mm) measures 254 mm across the diagonal: its sides come to only 180 mm. It does not reach the size the regulation calls for, even though the number 250 shows up in both calculations.
The configurator warns you
On all 69 large-containment placard designs, the 14 in. (356 mm) size is already selected when you open the design. If you go below it, a red notice appears under the size picker and reminds you of the rule.
It does not stop you from ordering: a 6 in. (152 mm) placard for training, for indoor display or for a desk magnet is perfectly legitimate. It just gives you the heads-up.
What we print, and what you have to check
Our files are reproductions drawn from the published specifications — they are not official Transport Canada files. The text is already converted to outlines and the image comes out at 300 dots per inch, at the exact size.
Whether the finished piece you put on your vehicle or your container meets the rules — dimensions, colours, durability of the material, weather resistance under section 4.6 of the regulation — is yours to verify. If a customer of yours has imposed Pantone targets, write to us before ordering: we set the press to them.
The material
A placard that lives outdoors, on a trailer or a tank, takes road salt, pressure washing and sun. Go with the gloss varnish: it is the layer that takes the wear instead of the print. For a placard that has to last years, composite aluminum panel is the substrate we recommend — it does not rust and it does not warp.