What class of fire does a dry chemical extinguisher primarily combat?

A dry chemical extinguisher is designed to combat multiple classes of fires, specifically Class A, Class B, and Class C fires. Class A fires involve ordinary combustible materials such as wood, paper, and cloth. Class B fires involve flammable liquids and gases, such as gasoline or oil. Class C fires are those that involve electrical equipment.

The versatility of dry chemical extinguishers stems from their use of powdered chemicals that can smother flames, interrupt the chemical reaction that fuels the fire, or displace oxygen. This makes them effective not only against fires fueled by solids and liquids but also effective in situations where electrical equipment might be involved, provided that the extinguisher is rated for Class C fires.

While they are not effective for all types of fires, such as those classified as Class D, which involve combustible metals, dry chemical extinguishers are widely regarded as one of the most versatile and commonly used fire suppression tools, making the option that includes Class A, B, and C fires the correct choice for this question.