Classes of Fire
Fires are classified into different classes based on the materials that are burning. Here are the five main classes of fire:
1. Class A: Fires Involving Ordinary Combustibles
Materials: Wood, paper, cloth, rubber, and plastics.
Characteristics: These are the most common types of fires, typically occurring in homes, offices, or other places where ordinary combustibles are present.
Extinguishing Method: Water or foam is typically used to extinguish these fires.
2. Class B: Fires Involving Flammable Liquids or Gases
Materials: Gasoline, oil, alcohol, paint, solvents, and other flammable liquids, as well as flammable gases.
Characteristics: These fires can spread rapidly because of the nature of the liquid or gas involved, and they may involve hazardous materials.
Extinguishing Method: Foam, CO2, or dry chemical extinguishers are used to smother the flames and prevent the liquid from spreading.
3. Class C: Electrical Fires
Materials: Energized electrical equipment (e.g., appliances, wiring, circuit breakers, computers, etc.).
Characteristics: These fires occur when electrical equipment malfunctions or is exposed to fire hazards, such as short circuits.
Extinguishing Method: CO2 or dry chemical fire extinguishers are commonly used for electrical fires because they do not conduct electricity, and using water on electrical fires can be extremely dangerous.
4. Class D: Fires Involving Combustible Metals and Lithium-ion Batteries
Materials: Magnesium, titanium, potassium, sodium, aluminum, and other combustible metals.
Characteristics: These fires are highly dangerous and can burn at very high temperatures. Water should never be used on Class D fires, as it can react violently with the metal instead a proper designed lithium ion battery fire extinguisher should be used.
Extinguishing Method: Specialized dry powder extinguishers are used to control these fires.
5. Class K: Cooking Oils and Fats Fires (Kitchen Fires)
Materials: Cooking oils, grease, and fats (typically in commercial kitchens or home kitchens).
Characteristics: These fires occur in deep fryers or cooking appliances when oils or fats become too hot and ignite.
Extinguishing Method: Wet chemical extinguishers are used to cool and smother the fire, as they are designed to handle the high temperatures and prevent re-ignition.
