What should be done if multipurpose dry chemical extinguishers are available?

Multipurpose dry chemical extinguishers are designed to tackle a variety of fire classes, specifically Class A (ordinary combustibles), Class B (flammable liquids), and Class C (electrical fires). The capability to effectively combat these fire types makes them versatile and a valuable resource in firefighting efforts.

When multipurpose dry chemical extinguishers are available, ensuring their use for both Class A and Class B fires (as specified in the correct answer) utilizes their designed functionality. These extinguishers use a dry chemical agent that can suppress flames from ordinary combustibles and flammable liquids, demonstrating their effectiveness across these fire classes.

While Class C fires involve electrical hazards and multipurpose extinguishers can be used effectively there as well, the emphasis in the correct response is on their primary application for Class A and B fires. Conversely, Class D fires, which involve combustible metals, and Class K fires, which pertain to kitchen fires typically involving cooking oils and fats, require specialized extinguishers and are not appropriate for multipurpose dry chemical extinguishers.