Which of the following materials is categorized as potentially presenting an explosive hazard?

Munitions debris is categorized as potentially presenting an explosive hazard because it often contains remnants of explosives, such as casings or fragments, which can detonate under certain conditions. This type of material poses a significant risk not only due to the potential for unintentional detonation but also because it may still contain explosive substances that can be activated by shock, friction, or heat.

In contrast, non-contaminated scrap metal, building materials, and used vehicles do not inherently contain explosive hazards. Non-contaminated scrap metal is typically safe unless it is associated with explosive devices. Building materials are generally stable and intended for construction purposes, posing little risk of explosion. Used vehicles may have combustible components or fluids, but they do not typically present an explosive hazard in the same manner as munitions debris.