What are the different types of fire extinguishers?

There are several different Types of Fire Extinguisher which are essential tools in fire safety, each designed for specific kinds of fires. The classification of fire extinguishers is based on the type of fire they are most effective in fighting. It’s crucial to use the correct type of extinguisher for the fire at hand to avoid ineffective suppression or even making the fire worse. Here’s a breakdown of the main types of fire extinguishers:

1. Water Extinguishers (Class A)

Water extinguishers are one of the most common and widely recognised types. They work by cooling the fire, removing heat, one of the essential elements of the fire triangle (heat, fuel, oxygen). Water extinguishers are suitable for fires involving ordinary combustibles such as wood, paper, textiles, and other organic materials. These types of fires are categorised as Class A fires.

Not suitable for:

• Fires involving electrical equipment (risk of electrocution)
• Flammable liquids like petrol or oils (Class B fires)
• Cooking oils and fats (Class F fires)

Example use: A fire in a wastepaper bin or wooden furniture.

2. Foam Extinguishers (Class A and B)

Foam extinguishers are versatile and can be used on Class A fires (combustible materials like paper and wood) and Class B fires (flammable liquids like petrol, oils, and paints). They work by forming a thick foam blanket over the burning surface, which smothers the fire by cutting off its oxygen supply, and by cooling the fire.

Not suitable for:

• Electrical fires (unless specifically rated for it)
• Fires involving cooking fats and oils (Class F fires)

Example use: A fire caused by spillage of petrol or oil, or a fire involving paper and wooden materials.

3. Carbon Dioxide (CO2) Extinguishers (Class B and Electrical Fires)

Carbon dioxide extinguishers are specifically designed for fires involving flammable liquids (Class B) and electrical fires. CO2 extinguishers work by displacing oxygen around the fire, effectively smothering it, and by cooling down the surrounding area to prevent re-ignition. They are non-conductive and safe to use on electrical equipment, making them ideal for office and machinery fires.

Not suitable for:

• Class A fires (e.g., wood, paper)
• Fires involving cooking oils and fats (Class F)

Example use: A fire in electrical wiring, computers, or flammable liquid spillage.

4. Dry Powder Extinguishers (Multi-Class: A, B, C)

Dry powder extinguishers are considered a multi-purpose option. They can be used on Class A fires (combustible materials), Class B fires (flammable liquids), and Class C fires (flammable gases such as propane and butane). The powder works by interrupting the chemical reaction that keeps the fire burning and can effectively smother fires.

However, they leave behind a residue that can cause damage, especially to electrical equipment. They are best suited for outdoor environments and industrial settings where versatility is needed.

Not suitable for:

• Fires in confined spaces (can impair visibility and breathing)
• Electrical fires (unless safe for such use)
• Fires involving cooking oils and fats (Class F)

Example use: A fire in a car engine or propane gas leak fire.

5. Wet Chemical Extinguishers (Class F)

Wet chemical extinguishers are designed for Class F fires, which involve cooking oils and fats (such as those used in deep fat fryers). They work by creating a chemical reaction that cools the burning oil or fat and forms a soap-like substance that smothers the fire. These extinguishers are specifically suited to kitchens and other areas where cooking oils are used.

Not suitable for:

• Class B fires (flammable liquids like petrol)
• Electrical fires

Example use: A fire in a commercial kitchen’s deep fryer or a pan of burning oil.

Fire Classification Overview:

• Class A: Fires involving solid combustibles (wood, paper, textiles).
• Class B: Fires involving flammable liquids (petrol, oils).
• Class C: Fires involving flammable gases.
• Class D: Fires involving combustible metals (special powder extinguishers required).
• Class F: Fires involving cooking oils and fats.

Using the right type of fire extinguisher is critical for fire safety. Incorrect use can not only be ineffective but also dangerous. Always make sure to check the label and ensure you are trained to use the extinguisher before an emergency occurs.

For more information on Types of Fire Extinguishers contact Total Safe UK.