Classes and Number Ratings of Fire Extinguishers

Description of materials extinguished by respective Class of Extinguisher

Ordinary combustibles (paper, wood, clothing)

Flammable liquids (gasoline, oil, grease, kerosene)

Energized electrical equipment (wiring, circuit breakers, machinery, and appliances)

Combustible metals such as magnesium, potassium and sodium.

Class K Fires

Grease fires involving commercial cooking equipment such as in restaurants.