Fire Extinguisher

Not all fires are the same, and they are classified according to the type of fuel that is burning. If you use the wrong type of fire extinguisher on the wrong class of fire, you can, in fact, make matters worse. It is therefore very important to understand the four different fire classifications.

Types of Fire

• Class A: Solid material fires that burn materials such as paper, wood, or plastic.
• Class B: Fires that involve flammable liquids, including paraffin, petrol, and oil.
• Class C: These flames burn on flammable gases such as propane, butane, and methane.
• Class D: Fires that ignite with metals such as aluminum, magnesium or titanium.
• Class E: Caused by electricity or involve electrical equipment and apparatus.
• Class F: These fires are ignited with oils or cooking fat.

Types of Fire Extinguishers

Different types of fire extinguishers are designed to fight different classes of fire. The different types of fire extinguishers are:

Foam Fire Extinguisher

1. Used for: Classes A and B
2. Dangerous if used for: Class F
3. How it works: The foam released by this extinguisher seals the surface of the burning material, preventing any stray materials from escaping and igniting elsewhere, as well as ultimately suffocating the fire. This extinguisher can be used on solid materials and flammable liquids such as paraffin and petrol (ClassesA and B), but not for chip and pan fires (Class F).

Water Fire Extinguisher

1. Used for: Class A
2. Dangerous if used for: Classes E and F
3. How it works: The water soaks the burning materials, such as paper, wood or fabric (Class A) and cools them down, completely putting out the fire. However, these extinguishers are very dangerous to use on oil and fat fires as well as electrical fires (Classes E and F).

Carbon Dioxide Fire Extinguisher

1. Used for: Classes B and E
2. Dangerous if used for: Class A and C
3. How it works: The carbon dioxide cuts off the oxygen supply to the fire, which smothers the blaze and puts it out. They are ideal for electrical fires and flammable liquids such as petrol and paraffin (Classes B and E) but are dangerous for use on solid materials and flammable gases including methane, propane or butane(Classes A and C).

Powder Fire Extinguisher

1. Used for: Classes A, B, C, and E.
2. Dangerous if used for: Class F
3. How it works: A powder is released and acts as a blanket which suffocates and cools the flames. The powder also prevents the flames from spreading, making it effective for most fire types including solid materials, flammable liquids, gases and electrical equipment (Classes A, B, C and E), however it’s not suitable for oil or pan fat fires(Class F). Specialist mixtures of powder extinguishers are available for fires involving metals (Class D).

Automatic Fire Extinguisher

1. Used for: Classes A, B, C and E
2. Dangerous if used for: Class F
3. How it works: Automatic fire extinguishers are ideal for locations where manual operation is not possible, or immediate activation is of utmost priority. They release an extinguishing agent when fire is detected, making them ideal for blazes involving solid materials, flammable liquids and gases as well as electrical fires (Classes A, B,C and E). However, they can’t be used in areas with a high risk of fire ignited by oils or fats (Class F).

Wet Chemical Fire Extinguisher

1. Used for: Class F
2. Dangerous if used for: Classes B, C, D and E
3. How it works: these extinguishers are specially formulated to tackle blazes involving oils and fats, with the chemicals reacting to create a fine film, suffocating the blaze. These extinguishers are perfect for use in kitchens with a high risk of fires involving cooking oils or fats (Class F),however they should not be used for any liquid, gas, metal or electrical fires (Classes B through to E).

Using a Fire Extinguisher

Fire extinguishers should not be used by people who have not been trained. Before tackling a fire with a fire extinguisher make sure you or someone else has raised the fire alarm and that you have a safe evacuation route.

Using the correct type of extinguisher for the fire, use the four-step PASS technique.

• Pull: Pull the pin, this will break the tamper seal.
• Aim: Aim low, pointing the nozzle or hose at the base of the fire. Do not touch the horn on a CO2 extinguisher, it gets very cold and can damage the skin.
• Squeeze: Squeeze the handle to release the extinguishing agent.
• Sweep: Sweep from side to side at the base of the fire, the fuel source, until the fire is out.