What type of materials fall under DOT Hazard Class 4?

DOT Hazard Class 4 pertains specifically to flammable solids. This classification includes materials that can easily ignite through friction, heat, or moisture, leading to potential hazards during transportation. Such materials often pose significant risks as they can contaminate environments or cause fires if not handled properly.

The other types of materials listed in different classes, such as radioactive substances, explosives, and oxidizers, fall under DOT Hazard Classes 7, 1, and 5, respectively. Each of these classes has unique characteristics and associated risks that differentiate them from the flammable solids in Hazard Class 4, which specifically emphasizes the ease of ignition and related hazards of solid materials. Understanding the specific categorization of hazardous materials is crucial for safe transportation and compliance with regulations.