How do you assign a UN number to a dangerous good?
How do you classify dangerous goods?

Within each class, a UN number, consisting of the letters UN followed by 4 digits, is assigned to each dangerous good in the class. The UN number (also known as the "heading") is :

• individual and nominative – it explicitly indicates the name of the material being transported;

• or collective – it covers a range of materials with the same characteristics.

Example:

• UN1263 PAINTINGS ;

• UN1477 INORGANIC NITRATES, N.O.S. ;

• UN1993 FLAMMABLE LIQUIDS, N.O.S.

ADR § 2.2.x (where x is the class number) indicates, for each class :

• physico-chemical criteria for class membership, class classification...