List of Fire Extinguisher Types and Color Codes
fire extinguishers are fairly portable active fire protection devices used to extinguish or control small fires, often in emergency situations
There are six main fire extinguisher types namely; water, foam, CO2, powder, water mist, and wet chemical.
Each of the different types of fire extinguisher is suitable for different fire classes/ scenarios It is important that you purchase the right fire extinguisher for your needs:
- Water: Class A fires (solid combustibles such as wood, paper, and textiles). Some water extinguishers are safe on electrical equipment if di-electrically tested. Otherwise, caution is required near electrical equipment, as ordinary water is a conductor.
- AFFF foam: Class A and B (flammable liquids). Safe on electrical equipment if di-electrically tested.
- Carbon dioxide (CO2): Class Band electrical equipment
- ABC powder: Class A, B, C(flammable gases) and electrical equipment
- De-Ionized water mist: Class A, B, Cand electrical equipment
- Wet chemical: Class F(deep fat) fires, sometimes class A
Fire extinguisher types and uses
Water fire extinguishers
Water extinguishers are only suitable for Class A fires consisting of paper, wood, straw, coal, rubber, solid plastics and soft furnishings. They are the simplest, most common, and least expensive type of extinguisher, some have an additive to make the water more effective and reduce the required size and weight of the extinguisher – these are a little more expensive.
Water extinguishers are the easiest to maintain variety and the least hazardous, since they only contain water. They cool the fire by soaking it and the materials with water. This extinguishes the flames, absorbing heat from burning objects.
They are often found in shops, offices, retail premises, schools, hotels, warehouses and domestic premises. They may have spray or jet nozzles and are usually able to put out a fire completely.
A drawback is that they cannot be used on burning fat or oil (Class F), burning metals (Class D), burning liquids (Class B), or electrical appliance fires.
Water mist extinguishers
The newest type of extinguisher. These very powerful, but smaller, devices exude an ultra-fine mist of microscopic ‘dry’ demineralized water particles. They are safe and effective to use on Class A, B, C, and F fires, making it unnecessary to supply more than one type of extinguisher on most premises. Some are also suitable for use on electrical fires on equipment up to 1,000 Volts, such as computers and printers.
They work by cooling the fire and reducing the oxygen supply. These devices are likely to replace wet chemical extinguishers for the extinction of deep fat fryer fires and leave no residue or collateral damage. Like water extinguishers, they are recyclable and do not contain any chemicals. However, they cannot be used on Class D fires (metals). Water mist extinguishers are more expensive than water extinguishers
Water spray fire extinguishers
Available in three- and six-liters water spray fire extinguishers are suitable for fires involving organic solid materials such as wood, cloth, paper, plastics, or coal. Use on burning fat or oil or on electrical appliances is a big no-no.
Use involves pointing the jet at the base of the flames and moving it constantly and steadily across the fire until extinguished.
A jet nozzle is eschewed in favor of a spray nozzle, which creates a fine spray courtesy of the higher pressure. Hitting a broader surface area extracts heat more rapidly. Surfactants can be added to help the water penetrate further into the burning material.
The foam smothers the fire in solids and liquids (Class A and B), but not in burning fats or cooking oils (Class F). They can be used on some electrical fires if they have been tested and if fired from 1 meter away. However, they leave a residue that has to be cleaned up, and they are more expensive than water extinguishers
Dry powder extinguishers
These are suitable for fighting burning solids, liquids, and gases (Class A, B, and C fires). Specialist powder extinguishers are designed to tackle type D fires involving combustible metals such as lithium, magnesium, or aluminum.
They work by the powder forming a crust that smothers the fire and stops it from spreading.
Disadvantages are that the powder does not soak into materials and does not have an effective cooling effect on the fire, which can result in the fire reigniting. The powder is hazardous if inhaled, so it should be used in well-ventilated areas and are not suitable for offices and domestic premises. The powder damages soft furnishings, machinery, etc., and needs a lot of cleaning up after use. They cannot be used on-chip pan fires (Class F).
These contain only pressurized carbon dioxide gas and therefore leave no residue. They are suitable for use on fires involving burning liquids (Class B), and electrical fires, such as large computer equipment, so are practical in offices. CO2 works by suffocating the fire and does not cause damage to the electrical items or cause the system to short circuit.
However, CO2 extinguishers get very cold during discharge, and those that are not fitted with double-lined, frost-free swivel horns may cause fingers to freeze to the horn during deployment. They can asphyxiate in confined spaces, and they are not suitable for deep fat fryers, as the strong jet from the extinguisher can carry the burning fat out of the fryer. Fires can quickly re-ignite once the CO2 has dissipated into the atmosphere, so they do not offer post-fire security. CO2 extinguishers are quite expensive
Wet chemical extinguishers
These are the only extinguishers apart from water mist suitable for Class F fires (fats and cooking oils) and are mainly used in kitchens with deep fat fryers. They can also be used on Class A and some can be used on Class B fires.
They consist of a pressurized solution of alkali salts in water, which, when operated, creates a fine mist, cooling the flames and preventing splashing..
Which fire extinguisher types to use
- Class A fires – water, water mist, foam, dry powder, wet chemical
- Class B – water mist, foam, dry powder, CO2, some wet chemical
- Class C – water mist, dry powder
- Class D – specialist dry powder
- Electrical – water mist, foam, CO2
- Class F – water mist, wet chemical.
Fire extinguisher use
Fire extinguishers should ideally only be used by someone who has been trained to do so – and the following text does not count as training.
Moreover, a fire extinguisher should only be activated once the fire alarm has been triggered and you have identified a safe evacuation route. Evacuate the building immediately if you still feel unsure about using a fire extinguisher or if doing so is clearly the safest option.
Nevertheless, the following technique can serve as a refresher for those who have undertaken training or if someone without training ever needs to use one in order to improve the chances that everyone escapes unharmed.
The following four-step technique can be memorized more easily with the acronym PASS:
- Pull: Pull the pin to 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 since it becomes 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 extinguished.
Fire blankets, hoses, and buckets
These methods of fire extinction are useful additions to extinguishers.
Fire buckets can be used filled with water on Class A fires, or with sand to use as an absorbing agent on spilled flammable liquids (Class B). They must not be used with water on burning fat or oil or on electrical appliances. However, they’re sometimes left empty or misused and have a limited effect as they can’t use on large fires
Fire hoses let out water at high pressure. They can be effective on Class A fires, but are very heavy.
Fire blankets are effective in smothering small, contained fires in kitchens or boats, if a good seal is made, and for wrapping round people whose clothing is on fire. Made of fiberglass, they can withstand temperatures of up to 500° C and are compact and portable. They don’t need any maintenance but can only be used once.
Automatic fire extinguishers
Automatic fire extinguishers are designed to combat fires in transport, such as in the engine compartments of boats or large vehicles, or in industrial use, such as in generators or computer rooms. Advantages include easy recharging and lack of constant monitoring, and removal of the need for manual operation in unmanned areas.
These extinguishers are designed to spring into action when they detect heat. On the downside, their placing is crucial, since they could be set off erroneously when the ambient temperature reaches the trigger level.
Available as dry powder (blue) or clean, inert extinguishing gas, which replaces the now illegal halon, banned because of its effect on the ozone layer (green), they protect against Class A, B, C, and electrical fires.
Vehicle fire extinguishers
Generally containing dry powder for tackling Class A, B, and C fires, their size should be selected according to the size and type of vehicle.