Which agent is suitable for use only on Class A fires?

Which agent is suitable for use only on Class A fires?

• A. water
• B. CO2
• C. Dry chemical
• D. Foam

Answer: (A)

Water works by absorbing a lot of heat and cooling the burning material below its ignition temperature. That cooling effect stops the combustion of ordinary combustibles like wood, paper, and textiles, which is exactly what Class A fires involve. Because water is so effective at cooling, it is the most appropriate choice for these fires. It isn’t suitable for other fire types: for flammable liquids (Class B) water can spread the spilled liquid and cause a flash fire; for energized electrical equipment fires, water can conduct electricity and pose a shock risk; for metal fires (Class D) water can react with certain metals; and for cooking fats (Class K) water can cause dangerous splattering. So water is the best fit for Class A fires and not recommended for the others.

Water works by absorbing a lot of heat and cooling the burning material below its ignition temperature. That cooling effect stops the combustion of ordinary combustibles like wood, paper, and textiles, which is exactly what Class A fires involve. Because water is so effective at cooling, it is the most appropriate choice for these fires. It isn’t suitable for other fire types: for flammable liquids (Class B) water can spread the spilled liquid and cause a flash fire; for energized electrical equipment fires, water can conduct electricity and pose a shock risk; for metal fires (Class D) water can react with certain metals; and for cooking fats (Class K) water can cause dangerous splattering. So water is the best fit for Class A fires and not recommended for the others.