Which class of fires involves ordinary combustibles?

Class A fires specifically involve ordinary combustibles, which are materials such as wood, paper, cloth, rubber, and many plastics that can ignite and burn when exposed to heat. These materials are commonly found in residential and commercial settings, making Class A fires among the most common types firefighters encounter.

Water is typically used to extinguish Class A fires as it effectively cools the burning materials and removes the heat from the fire triangle, which consists of fuel, heat, and oxygen. Understanding the characteristics of Class A fires is essential for effective firefighting and safety measures, ensuring that firefighters can respond appropriately to these common fire scenarios.

The other classes of fires—Class B (flammable liquids and gases), Class C (electrical fires), and Class D (combustible metals)—involve different materials and require distinct approaches for extinguishment, making them not applicable to ordinary combustibles.