Which extinguisher is not considered safe for class A fires?

For Class A fires, which typically involve ordinary combustible materials such as wood, paper, and textiles, it's important to select the appropriate type of extinguisher. Carbon dioxide (CO2) extinguishers are effective for Class B (flammable liquids) and Class C (electrical) fires, as they work by displacing oxygen and smothering the fire. However, CO2 is less effective on Class A fires because it does not cool the burning material and may not prevent re-ignition.

In contrast, foam extinguishers can effectively cool and smother the flames, and they are suitable for Class A fires. Similarly, dry powder extinguishers can extinguish Class A fires, along with Class B and C. Wet chemical extinguishers are specifically designed for Class K fires (cooking oils) but can also be effective on Class A fires due to their cooling properties.

Understanding the limitations and effectiveness of different extinguishers for various fire classifications is crucial for proper fire safety training and emergency response.