Which of the following best describes the characteristics of UN Hazard Class 4?

UN Hazard Class 4 is categorized specifically for flammable solids. This class includes solid materials that can readily ignite and may cause combustion through friction, heat, or contact with moisture. Flammable solids can pose serious fire hazards, and their characteristics include the ability to burn rapidly and potentially produce harmful fumes.

Understanding this classification is crucial for fire and emergency services personnel because it informs how these materials should be handled, stored, and transported safely. Recognizing the specific risks associated with flammable solids can improve safety protocols during emergencies and ensure proper responses to incidents involving such substances.

In contrast, gases, toxic substances, and flammable liquids belong to other hazard classes, each with distinct characteristics and requirements for handling, storage, and emergency response that do not apply to Class 4 materials.