On which type of fires are carbon dioxide extinguishers effective?

Carbon dioxide extinguishers are specifically designed to be effective against B and C Class fires. Class B fires involve flammable liquids such as gasoline, oil, and paints, while Class C fires are associated with electrical equipment. The reason carbon dioxide extinguishers are suitable for these types of fires is due to their ability to displace oxygen in the fire's environment, effectively suffocating the flames without leaving any residue. This makes them particularly useful for electrical fires, as they do not conduct electricity and can be safely used on energized equipment.

In contrast, Class A fires, which involve ordinary combustibles like wood, paper, and textiles, are not effectively extinguished with carbon dioxide, as these fires require water or specific types of chemical extinguishers to cool the materials and suppress the flames. Therefore, the choice indicating that carbon dioxide extinguishers are effective on B and C Class fires aligns with the intended use and characteristics of this type of extinguisher.