What defines a “hazard class”?

A "hazard class" is defined as a categorization system for hazardous materials based on the type of hazard they present. This classification is crucial for ensuring that materials are handled, stored, and transported in a manner that mitigates the risks associated with those specific hazards. For example, different classes cover flammable substances, corrosive materials, toxic agents, and other categories, each with tailored safety regulations and handling procedures.

By having a systematic approach, regulatory authorities such as the Department of Transportation can enforce safety measures that protect workers, the public, and the environment. This classification allows shippers, handlers, and emergency responders to identify the risks and necessary precautions involved in dealing with different types of hazardous materials.

Other options, while they might involve categorization in some context, do not align with the specific definition of a hazard class. The concept of usage frequency, shipping costs, or geographic classification does not focus on the inherent dangers presented by the materials themselves, which is the core purpose of defining a hazard class.