2. Classifications and codifications

These classifications relate to the hazardous materials themselves, according to the nature and extent of the hazards involved, with reference to UN recommendations.

These are the codes used for dangerous goods transport packaging, also with reference to UN recommendations.

Dangerous goods are divided into "classes", with an indication of certain special features, such as secondary risks. These goods are presented in the form of alphabetical and/or numerical lists, giving, in addition to the name of the goods, their UN number, their class, any secondary risks, authorized packaging, labels to be affixed and special instructions. These lists can be found in the various regulations cited in §