Which type of extinguishers is ineffective against special hazards?

The effectiveness of extinguishers against specific types of fire hazards varies based on the materials involved in the fire. Type B extinguishers are designed to combat fires involving flammable liquids and gases, such as oil, gasoline, and paints. They work effectively on these types of fires but do not provide adequate protection against special hazards like combustible metals, which may require specialized extinguishing agents.

Special hazards refer to fires involving materials that necessitate specific extinguishing techniques or agents that are not covered by standard Type B extinguishers. For example, Type D extinguishers, which are specifically formulated for combustible metal fires, would be the appropriate choice for such situations.

While Type A extinguishers are intended for ordinary combustible materials like wood, paper, or cloth, and Type C extinguishers are designed for electrical fires, neither Type A nor Type C specifically addresses the characteristics of special hazards as comprehensively as Type D extinguishers do. Thus, recognizing that Type B extinguishers are not equipped to handle special hazards helps clarify why this choice is applicable in this context.