How many classes are Dangerous Goods Hazardous Materials (DGHM) grouped into?

Dangerous Goods Hazardous Materials (DGHM) are classified into nine distinct classes according to the United Nations Model Regulations on the Transport of Dangerous Goods. Each class corresponds to a specific type of hazard associated with the materials being transported, ensuring that they are handled and transported with the appropriate safety measures in place.

Class 1, for example, relates to explosives, while Class 2 is designated for gases. This classification system aids in the identification and management of risks during transport, making it crucial for compliance with aviation safety regulations. Therefore, the total of nine classes is essential for organizing and regulating the transportation of hazardous materials effectively, which justifies the selection of this answer as the correct one.