Flammable solids that may cause burns or inhalation hazards belong to which class?

• A. Class 2
• B. Class 3
• C. Class 5
• D. Class 4

Answer: (D)

Flammable solids are grouped under Class 4 because this category covers materials that ignite easily and can burn, sometimes producing hazardous vapors that pose inhalation risks. The phrase “solids that may cause burns or inhalation hazards” describes the core behavior of flammable solids: they can ignite and burn readily, and some can release flammable or toxic vapors when involved in a fire or reaction. This is distinct from gases (Class 2), flammable liquids (Class 3), or oxidizing substances and organic peroxides (Class 5), which represent different types of hazards.