What the plate carries
Federal rules require IBC markings to include the UN symbol, the design code, the letter X, Y or Z for packing group, the month and year of manufacture, the country, the manufacturer, the stacking test load in kilograms and the maximum permissible gross mass in kilograms. Composite and rigid plastic IBCs must also be marked with the month and year of the last leakproofness test and the last inspection.
That is a lot of text on a small plate, and it is the document that decides whether a tote may be reused for hazardous liquids.
| Field | What it tells you |
|---|---|
| UN symbol | The tote meets a UN design standard |
| 31HA1 | Plastic receptacle in steel outer packaging, for liquids |
| X, Y or Z | The packing groups the tote is approved for |
| Month and year of manufacture | How old the tote is |
| Last leak test and inspection | When it was last checked |
| Stacking load, kg | The load the cage can carry |
| Maximum gross mass, kg | The most the filled tote may weigh |
How to read the design code
The 3 says it is an IBC. The 1 means for liquids. The H stands for composite packaging, with a plastic receptacle. The A names the outer material, steel. The last 1 is the type. So 31HA1 is the common caged poly tote: HDPE bottle in a galvanized steel cage.
Check the date first. A tote shipping hazardous liquids needs a current test, covered on the retest dates guide.
What to do with a plate you cannot read
- A scratched or painted-over plate is a problem. Do not paint over it.
- Photograph the plate and send it with the request.
- If the plate is missing, the tote cannot go back into hazmat service.
- Non-hazardous liquids have fewer plate rules; ask your carrier.
Photographing a plate so it can be read
A plate is often dirty, shaded by the cage or scratched by forklift tines. Wipe it with a damp cloth first. Take one photograph square on, with the sun behind you so the stamped letters throw a shadow, and a second at a shallow angle with raking light, which makes embossed characters stand out.
Send both with your request, together with a photograph of the whole tote so the plate can be tied to the cage and bottle. If the plate is on the bottle and the cage was replaced, say so: the pairing matters when the dates on the two parts differ.
A stamped plate versus a sticker
A genuine plate is stamped or embossed, not printed. A printed sticker with the same code can be a sign of a refurbished or non-certified tote. If in doubt, ask for the certification paperwork.
When the plate and the tote disagree
If the plate on the cage shows a different date from the one on the bottle, the earlier date governs. A mismatch is not a fault in itself, but it should be recorded.
Questions people ask
What does 31HA1 mean?
A composite IBC with a plastic inner receptacle and a steel outer packaging, for liquids.
Where is the plate?
On the cage or bottle. Look near the lower corner of one side.
Sources. Last reviewed 2026-11-11.