The UN assigns a packing group classifying the regulated material further by the amount of risk each material poses during transportation. The packing group also determines the degree of protective packaging required.
Packing Group I – Greatest Danger
- Shown as X in the UN marking on the package.
- Some combinations of different classes of dangerous goods on the same vehicle or in the same container are forbidden if one of the goods is Packing Group I.
Packing Group II – Medium Danger
- Shown as Y in the UN marking on the package.
Packing Group III – Least Danger
- Shows as Z in the UN marking on the package.