Which of the following is an example of Class A ordinary combustible materials?

• A. Wood
• B. Grease
• C. Electrical wire
• D. Magnesium metal

Answer: (A)

Class A ordinary combustibles are solid materials that burn with a visible flame and leave ash, such as wood, paper, and cloth. Wood fits this category perfectly because it is a common solid fuel that ignites and burns with an ordinary flame and forms ash as it combustion proceeds.

Grease is a flammable liquid, which places it in Class B. Electrical wire involves energized electrical equipment, placing it in Class C. Magnesium metal is a combustible metal, categorized as Class D. Recognizing these classifications helps determine the appropriate extinguishing approach for each type of fire.