A fire extinguisher is a portable device designed to put out small fires or control them until help arrives. It consists of a cylindrical pressure vessel containing an agent that can be discharged to extinguish flames. Fire extinguishers are classified by the type of fire they are designed to fight: Class A for ordinary combustibles like wood and paper, Class B for flammable liquids, Class C for electrical fires, Class D for combustible metals, and Class K for kitchen fires involving cooking oils and fats. Proper use involves following the PASS technique: Pull the pin, Aim the nozzle, Squeeze the handle, and Sweep the nozzle from side to side at the base of the fire. Fire extinguishers are essential safety tools in homes, workplaces, vehicles, and public spaces, providing a first line of defense in fire emergencies.

Fire extinguishers come in various types, each designed to combat specific classes of fires. Here are the main types of fire extinguishers:

1. Water Extinguishers (Class A):

   • Suitable for: Ordinary combustibles like wood, paper, and textiles.
   • Not suitable for: Flammable liquids, electrical fires, and cooking oils.
   • Types: Water jet, water spray, and water mist.

2. Foam Extinguishers (Class A and B):

   • Suitable for: Flammable liquids like petrol, oil, and solvents, as well as ordinary combustibles.
   • Not suitable for: Electrical fires and cooking oils.

3. Dry Powder Extinguishers (Class A, B, C, and sometimes D):

   • Suitable for: Combustible metals (Class D), flammable liquids (Class B), flammable gases (Class C), and ordinary combustibles (Class A).
   • Not suitable for: Cooking oils (Class K) and sensitive electrical equipment.
   • Types: Standard dry powder and specialist dry powder for metal fires.

4. Carbon Dioxide (CO2) Extinguishers (Class B and Electrical):

   • Suitable for: Flammable liquids and electrical fires.
   • Not suitable for: Ordinary combustibles, cooking oils, and combustible metals.

5. Wet Chemical Extinguishers (Class K and sometimes A):

   • Suitable for: Cooking oils and fats (Class K), and sometimes ordinary combustibles (Class A).
   • Not suitable for: Flammable liquids, gases, electrical fires, and combustible metals.

6. Class D Extinguishers:

   • Suitable for: Combustible metals like magnesium, titanium, and sodium.
   • Not suitable for: Ordinary combustibles, flammable liquids, gases, and electrical fires.

Each type of fire extinguisher is specifically formulated to effectively combat the type of fire it is designed for, ensuring maximum safety and efficiency in fire emergency situations.