Firefighting

There are six classes of fire but five are classified according to the fuel burning.

1. Class A fire: These are common fires. They are fueled by burning of organic materials such as wood, paper, rubber, clothes, and plastic.
2. Class B fire: These are fueled by flammable liquids such as petrol, kerosene, alcohol, diesel, and oils.
3. Class C fire: These are fueled by flammable gases such as natural gas, biogas, and liquefied petroleum gas.
4. Class D fire: These are fueled by burning metals, for example sodium, potassium, lithium, and magnesium.

Fire extinguishers

A fire extinguisher is an active fire protection device used to extinguish or control small fire often in emergency situations. A portable fire extinguisher is an extinguisher that can be easily moved from one place to another.

There are four common types of portable fire extinguishers, namely:

1. Dry powder extinguishers: Contain sodium bicarbonate powder pressurized by nitrogen. Extinguish the fire by separating the fuel from the oxygen element or by removing the heat element of the fire triangle.
2. Foam extinguishers: Contains proteins and fluoroproteins. Extinguish fire by taking away the heat element of the fire triangle. Foam agents also separate the oxygen element from the other elements.
3. Water extinguisher: Contains ordinary tap water pressurized air. Extinguish fire by taking away the heat element of the fire triangle.
4. Carbon dioxide extinguisher: Contain CO₂, a non-flammable gas, and are highly pressurized air. Extinguish fire by taking away the oxygen element of the fire triangle and also by removing the heat with very cold discharge.

Using fire extinguishers

The fire extinguisher should be used based on the following "PASS" technique:

• PULL — The safety pin from the handle. The pin is located at the top of the fire extinguisher. Once removed, it releases the locking mechanism, allowing you to discharge the extinguisher.
• AIM — The extinguisher nozzle at the base of the fire. As explained, this removes the source or fuel of the fire. Keep yourself low.
• SQUEEZE — The handle slowly to discharge the agent. Letting go of the handle will stop the discharge, so keep it held down.
• SWEEP — Sweep side to side over the fire until the sweeping motion helps to extinguish the fire. Stand a few meters back from the fire.

When using a portable fire extinguisher, it's important to follow certain safety precautions to ensure proper and safe use. Here are some key precautions to remember:

1. Maintain a safe distance Always keep a reasonable distance (at least 1.5 m) from the fire, as the flames or fire may suddenly change direction.
2. Use a fire blanket for a person on fire If a person catches fire, use a fire blanket to smother the flames rather than a portable fire extinguisher.
3. Do not test without permission Never test a portable fire extinguisher at school or other places without prior permission. Testing could cause unnecessary danger.
4. Do not return a used extinguisher to the wall After use, do not return a portable fire extinguisher to its usual place on the wall until it has been checked and refilled by a professional.
5. When fire is out of control If the fire becomes too large or unmanageable, abandon the area immediately and notify the nearest firefighting squad (fire brigade).