How UN-spec packaging is built, tested, marked, and selected — by hazard class and packing group.
Every UN-spec package carries a marking that tells you, in one line, what it is and what it's certified for. Example:
u n 4G/Y25/S/24/USA/+AA1234
| Segment | Meaning |
|---|---|
| 4G | Packaging type — fibreboard box |
| Y | Packing group II/III (tested to PG II level) |
| 25 | Gross mass in kg (solids) or specific gravity (liquids) |
| S | Solids / inner packagings |
| 24 | Year of manufacture |
| USA | Country authorising the mark |
| +AA1234 | Manufacturer / approval reference |
| PG | Danger level | Marking letter |
|---|---|---|
| I | Great danger | X (covers I, II, III) |
| II | Medium danger | Y (covers II, III) |
| III | Minor danger | Z (covers III only) |
Liquids, closed-head steel.
Liquids, closed-head HDPE.
Liquids, closed jerrican.
Common outer for combination packagings.
Reusable rigid plastic.
Plastic receptacle in a steel drum.