A dry chemical extinguisher is a type of fire extinguisher that uses a dry chemical powder to put out fires. It is effective against various classes of fires, including Class A (ordinary combustibles), Class B (flammable liquids), and Class C (electrical fires). The powder works by interrupting the chemical reaction of the fire, smothering the flames and preventing re-ignition. These extinguishers are commonly found in homes, offices, and industrial settings due to their versatility and ease of use. They typically come in different sizes and are labeled with specific instructions for operation. Regular maintenance is essential to ensure they function properly when needed.