There are five broad types of fire extinguishers – Water, Foam, Dry Powder, CO2, and Wet chemicals. To protect you and your surroundings against fire and ensure that your business meets current fire safety regulations, you need to make the right fire extinguisher choice. These fire extinguisher types are divided based on the fire classes classified based on the trigger triggering the fire. The presence of these fuels in your business surroundings and premises helps determine the best fire extinguisher that meets all your needs. The placement of these fire extinguishers is dependent on the substances that can add to the fire, such as oils, chemicals, etc. 

Choosing the right size and weight of an extinguisher is as crucial as selecting the correct type of fire extinguisher. A fire safety system needs to be in place when opening a new business that ensures the safety of everyone present near and inside the building. Fire extinguishers are passive fire protection devices that help reduce and extinguish the fire that various triggers and reasons can cause.

The Classes of Fire

Fire can be classified into six categories:

  • Combustible materials such as flammable solids, such as wood, paper, and textiles, are responsible for causing Class A fires.
  • Flammable liquids such as petrol, paints, or spirits cause Class B fires. 
  • Class C fires are caused by flammable gases such as propane and butane.
  • Flammable metals such as magnesium, lithium, or potassium cause Class D fires.
  • Class E fires are caused by short circuits and electrical equipment such as computers and photocopiers. Once the electrical item is removed from the area, the fire changes class. 
  • Class F fires are caused by cooking oils such as olive oil or butter like a typical chip-pan fire.

Types of Fire Extinguishers

Water Extinguishers

Water fire extinguishers are the most common fire extinguisher that is optimum for a Class A fire. These extinguishers distribute high pressured water to extinguish flames. Water fire extinguishers are the most common that can be found on-premises all around the UK. The label for water extinguishers is bright Red. These extinguishers are best suited for fire caused by textiles, coal, wood, cardboard, paper, and fabrics.

In case of fire caused due to electronic equipment, flammable liquid or gas, and kitchen fires, water fire extinguishers should not be used.

Water fire extinguishers provide a cooling effect on the fire’s fuels targeting the source of the fire- the heating element required to keep the fire burning. This reduced the burning rate, causing fire to burn slower, ultimately resulting in fire extinguishing.

Water fire extinguishers are standard and used throughout most buildings in the UK. The types of businesses and structures that use this fire extinguisher are schools, hospitals, offices, apartments, and shops. Water fire extinguishers must be placed near exits on floors that have been flagged as a Class A fire risk area during your latest fire risk assessment. 

Foam Extinguishers

Foam fire extinguishers are used to serve Class B fires. These extinguishers are water-based, making them a sound choice for class A fires as well. The label colour of foam fire extinguishers is cream.

Foam extinguishers work on a similar concept as water fire extinguishers. They are used for fires involving organic materials such as cardboard, paper, fabrics, coal, and wood. Foam extinguishers have proven effective on fires caused by flammable liquids such as petrol or paint as well.

Foam fire extinguishers are not meant to be used in fires that are caused due to electronic equipment, flammable metals, and kitchen fires. Foam extinguishers create a cooling effect on the fire accelerant targeting the heating element of the fire. The foaming agent forms a barrier between the flames of the fire and the fuel required to stabilize the fire, which ultimately results in the fire being extinguished.

Foam fire extinguishers are used on buildings where flammable liquids are contained, and organic materials are present inside these buildings. Buildings that require foam extinguishers as a part of the fire system in the UK are schools, hospitals, offices, apartments, and shops. These are stored at exit points in buildings in areas marked risky as a Class A or Class B fire risk.

Dry Powder Extinguishers

Dry Powder extinguishers are ABC extinguishers used in Class A, B, or C fires. Dry powder extinguishers are restricted in an enclosed area as the powder used for extinguishing the fire is hazardous if inhaled and can be very difficult to clean up once the fire has died down. Dry powder extinguishers are used on fires caused by electronic equipment. These extinguishers may be used on fires caused by flammable metals as well. The label colour for dry powder extinguishers is blue.

Dry powder extinguishers aim at fires caused by organic materials such as wood and coal, fabrics, cardboard, and paper. They are used to extinguish fire caused by flammable gases such as liquid petroleum, electrical equipment, and flammable liquid like petrol. Dry powder extinguishers cut off the oxygen supply needed to carry on the fire causing it to die down. The businesses that benefit from this fire extinguisher are garage forefronts, welding or flame cutting companies, large broiler rooms, and LPG dispensing plants. They should be stored next to the fire-causing element that is at risk.

Carbon Dioxide Extinguishers

Carbon dioxide fire extinguishers are used in electrical fires such as in computer server rooms or an area consisting of many electrical devices. The label colour for this type of extinguisher is black. It can extinguish fires caused due to flammable liquids such as petrol. It should not be used in the case of fires involving combustible metals, papers or textiles, and kitchen fires.

The CO2 extinguishers replace oxygen with CO2, which suffocates the fire causing the fire to burn out. The businesses that can benefit from this extinguisher are server rooms, offices, and technology stores. CO2 extinguishers should be placed next to the source of the fire risk or near fire exits.

Wet Chemicals Extinguishers

Wet chemical extinguishers are used in Class F fires that involve cooking oils and fats. This type of extinguisher can be used in class A fire, but water and foam extinguishers are better suited for Class A fires. The label colour for wet chemical extinguishers is yellow. It is not meant to be used for fires involving flammable liquids or gases, electrical fires, and combustible metals. 

It creates a foam layer on the burning oil or fat surface and suffocates oxygen from the heating point. The chemical contained in the extinguisher is potassium distributed in the form of a fine mist on the affected area. Potassium creates a soapy foam when interacting with oil or fat, which results in the fire burning itself out.

The types of companies that can benefit from wet chemical extinguishers are commercial kitchens, restaurants, and canteens. These extinguishers should be placed next to the source of the fire risk.