Types Of Fire Extinguishers Explained

Fire extinguishers are designed to tackle different types of fire. Choosing the correct extinguisher is important because using the wrong type can make a fire worse or create additional danger.

In the UK, fire extinguishers are commonly identified by their label colour, contents and the class of fire they are suitable for. Understanding the main types can help businesses, employees and property managers improve fire safety awareness.

Fire Classes Explained

Before looking at extinguisher types, it is useful to understand fire classes. These describe the type of material that is burning.

• Class A: solid materials such as wood, paper, textiles and cardboard
• Class B: flammable liquids such as petrol, paint and solvents
• Class C: flammable gases such as propane, butane and methane
• Class D: burning metals such as magnesium, aluminium or titanium
• Class F: cooking oils and fats
• Electrical fires: fires involving live electrical equipment

Water Fire Extinguishers

Water extinguishers are usually identified by a red label. They are mainly used on Class A fires involving solid combustible materials such as paper, wood and fabric.

They work by cooling the burning material and reducing the temperature below the point of ignition.

• Suitable for: wood, paper, cardboard and textiles
• Not suitable for: flammable liquids, cooking oil or live electrical equipment

Foam Fire Extinguishers

Foam extinguishers are usually identified by a cream label. They are suitable for Class A and Class B fires, making them a common choice in many workplaces.

Foam works by cooling the fire and forming a blanket over flammable liquids to help prevent re-ignition.

• Suitable for: paper, wood, textiles, petrol, paint and some flammable liquids
• Not suitable for: cooking oil fires or certain electrical risks unless clearly stated on the extinguisher

CO2 Fire Extinguishers

Carbon dioxide, or CO2, extinguishers are usually identified by a black label. They are often used for fires involving live electrical equipment because they do not leave residue.

CO2 extinguishers work by displacing oxygen around the fire and are also suitable for some Class B flammable liquid fires.

• Suitable for: electrical equipment and flammable liquids
• Not suitable for: cooking oils, deep fat fryers or confined spaces without proper care

Dry Powder Fire Extinguishers

Dry powder extinguishers are usually identified by a blue label. They are versatile and can be used on Class A, B and C fires, including fires involving flammable gases.

They work by interrupting the chemical reaction within the fire. However, they can reduce visibility and leave a powder residue, so they are not always suitable for indoor use unless specified by a fire risk assessment.

• Suitable for: solids, flammable liquids and flammable gases
• Not suitable for: enclosed indoor areas where powder discharge could cause visibility or breathing issues

Wet Chemical Fire Extinguishers

Wet chemical extinguishers are usually identified by a yellow label. They are specially designed for Class F fires involving cooking oils and fats.

They work by cooling the fire and creating a layer over the burning oil to help prevent re-ignition. They are commonly used in commercial kitchens, restaurants, cafés and food preparation areas.

• Suitable for: cooking oil and fat fires
• Also suitable for: some Class A fires, depending on the extinguisher
• Not suitable for: flammable gases or live electrical equipment unless clearly rated

Specialist Fire Extinguishers

Some environments require specialist extinguishers for specific risks. For example, Class D metal fire extinguishers are used where combustible metals are present, such as in certain engineering, manufacturing or laboratory settings.

These extinguishers should only be selected following a suitable fire risk assessment and used by trained personnel.

Fire Extinguisher Colour Codes

Modern UK fire extinguishers are generally red with a coloured label showing the contents. Common label colours include:

• Red: water
• Cream: foam
• Black: CO2
• Blue: dry powder
• Yellow: wet chemical

Which Fire Extinguisher Do You Need?

The correct fire extinguisher depends on the fire risks present in the building. An office may require different extinguishers from a workshop, warehouse, garage or commercial kitchen.

A fire risk assessment should identify the types of fire that could occur and help determine the most suitable extinguishers, locations and signage.

Fire Extinguisher Signs

Fire extinguisher signs help people quickly identify the location and type of extinguisher available. They can also show what the extinguisher can and cannot be used on.

Clear signage is especially useful in busy workplaces, public buildings and shared premises where people may not be familiar with the fire safety arrangements.

Important Safety Advice

Only use a fire extinguisher if it is safe to do so, you have been trained or instructed, and the fire is small and contained. If there is any doubt, raise the alarm, leave the building and call the emergency services.

Never put yourself or others at risk when attempting to fight a fire.

Conclusion

There are several different types of fire extinguishers, each designed for specific fire risks. Water, foam, CO2, dry powder and wet chemical extinguishers all have different uses, benefits and limitations.

By choosing the correct extinguishers, displaying clear fire extinguisher signs and keeping equipment properly maintained, businesses can support safer workplaces and improve emergency preparedness.