The Manual of Tests and Criteria contains criteria, test methods and procedures to be used for classification of dangerous goods according to the provisions of Parts 2 and 3 of the United Nations Recommendations on the Transport of Dangerous Goods, Model Regulations, as well as of chemicals presenting physical hazards according to the Globally Harmonized System of Classification and Labeling of Chemicals (GHS). As a consequence, it supplements also national or international regulations which are derived from the United Nations Recommendations on the Transport of Dangerous Goods or the GHS.

The classification procedures, test methods and criteria contained in the Manual of Tests and Criteria are divided into three parts, as follows:

• Part I: Those relating to assignment of explosives to Class 1.
• Part II: Those relating to assignment of self-reactive substances to Division 4.1 and of organic peroxides to Division 5.2
• Part III: Those relating to assignment of substances or articles to Class 3, Class 4, Division 5.1 and Class 9.
• The fourth revised edition includes revised provisions for the classification of lithium batteries (sub-section 38.8) and new provisions for the classification of ammonium nitrate emulsions (section 18), flammable aerosols (section 31) and substances corrosive to metals (section 37).