At MCFP, we specialise in fire safety for your commercial or residential property. Our highly-skilled, experienced, BAFE registered technicians can conduct a full fire safety audit of your premises and offer expert advice on how to optimise the safety of your building using fire extinguishers and other fire protection equipment. We also provide in-depth commissioning, servicing and maintenance to ensure the quality and safety of your extinguishers for many years to come.
Classes of Fire
Fires are divided into classes depending on the type of material that is burning, and different fire extinguishers are used to tackle each different class of fire. So, when installing fire extinguishers on your premises it is essential to consider the level of risk of each class of fire that your building poses. This can be ascertained through a fire risk assessment.
The different classes of fire are:
Class A – involves the combustion of organic materials such as wood, paper and fabric. Class A fires tend to be the most common type of fire.
Class B – involves the combustion of flammable liquids such as petrol, oil, paraffin, alcohol and certain paints.
Class C – involves flammable gases such as butane and propane as well as natural gases that are used when cooking or heating a building.
Electrical – involves electrical equipment.
Class F – often referred to as kitchen fires because they primarily involve cooking or vegetable oils
Type of Fire Extinguisher
ABC POWDER
AFF FOAM
CARBON DIOXIDE
WATER
WATER MIST
WET CHEMICAL
Fire Classification
Fire Extinguisher Suitability
Powder fire extinguishers: ideal for use in mixed-risk environments and offer excellent all-around fire protection.
Foam fire extinguishers: excellent for use on fires involving solid, flammable materials and are very efficient on liquid fires.
CO2 fire extinguishers: suitable for use on flammable liquid fires and are remarkably efficient at extinguishing a fire involving electrical equipment.
Water fire extinguishers: useful in situations that contain solid, flammable materials such as textiles, wood or paper.
Water mist extinguishers: perfect for covering building spaces where multiple fire risks can be found.
Wet chemical extinguishers: the perfect solution for tackling large burning oil fires and also ideally suited to the kitchen environment.
Main Fire Extinguisher Categories
There are five main fire extinguisher categories: Water, Foam, Dry Powder, CO2 and Wet Chemical.
- 1. Water Extinguishers Recommended for Class A fires
- 2. Foam extinguishers Recommended for Class A and B fires
- 3. Powder Extinguishers (Dry Powder Extinguishers) Recommended for Class A, B and C fires
- 4. Carbon Dioxide (CO2) Extinguishers Recommended for Class B fires & safe for electrical equipment.
- 5. Wet Chemical Extinguishers Recommended for Class A and F fires
1. Water Extinguishers
Water fire extinguishers offer the most cost-effective way to fight Class A fires and those fuelled by thick organic materials such as textile or paper. Water is effective at putting out a fire as it has an extremely cooling effect on the fuel. Removing the element of heat - one of the three essential elements to ignite a fire - causes the fire to extinguish.
There are four sub-types of water extinguishers:
- Water with additives – chemicals are added to the water supply to reduce the surface tension of the water, making it more effective at extinguishing the fire.
- Water jet – a high-pressure jet of water is expressed through the nozzle directly onto the burning fuel.
- Water spray – contains no added chemicals and simply uses a fine spray of tap water to extinguish the fire.
- Water mist or fog – smothers the flames using a fine mist of water droplets. By using a mist versus a stream, the water has a higher surface area to volume ratio and can cover a larger area of the fire.
2. Foam Extinguishers
Foam extinguishers are designed for Class A and B fires. These extinguishers are most suited to extinguishing liquid fires as they are more versatile than conventional water jet extinguishers and can be used on any kind of solid material including wood and paper.
Foam extinguishers work by suffocating the fire with a thick layer of foam, sealing the surface of the liquid and preventing combustible vapour from entering the air.
3. Powder Extinguishers (Dry Powder Extinguishers)
Powder extinguishers are often called multi-purpose extinguishers given their usability on Class A, B, and C types of fire. Powder extinguishers can also be used to put out fires involving electrical equipment. However, powder extinguishers do not cool down the fire, therefore there is always a chance of re-ignition.
Powder extinguishers can also create a loss of visibility and breathing problems, so they are not recommended for use inside buildings unless there is no alternative. The building must be properly ventilated after the discharge of a powder extinguisher.
4. Carbon Dioxide (CO2) Extinguishers
CO2 fire extinguishers are ideal for areas containing electrical devices, such as offices or server rooms. These extinguishers work by suppressing the fire and cutting off its supply of oxygen. CO2 extinguishers do not leave any debris, unlike foam extinguishers.
CO2 extinguishers can also be used on Class B fires, such as flammable liquids, paraffin or petrol.
5. Wet Chemical Extinguishers
Wet chemical fire extinguishers are best suited for tackling Class A and F fires. These fire extinguishers contain a chemical called potassium which reacts with cooking oil/fat and forms a layer of film over the fire. This creates an instant cooling effect on the fuel itself and also prevents oxygen from reaching the fire.
For more information on selecting the right fire extinguishers for your workplace, check out our workplace fire extinguisher guide blog which discusses this in more depth.
