Fires are divided into five main types, depending on the nature of the fuel involved
Class A fires involve solid fuels, such as wood
Class B fires involve flammable liquids, such as petrol
Class C fires involve gas
Class D fires involve metals, such as potassium or magnesium
Class F fires involves cooking oils
Formerly there was a classification of electrical fires, but since electricity itself is a cause of fire, not a fuel in itself, these types of fires have been incorporated into the main classes. If you think about it, once you have removed the electricity - i.e. turned the power off or it fuses itself - the fire becomes a normal fire. Some extinguishers are labelled as safe for use on fires involving electrical equipment.
Portable Fire Extinguishers: Use The Right Tool For The Job
Fire extinguishers are designed to tackle specific fire types, and particular fire sizes. In addition to labels indicating what fire types they should be used on, fire extinguishers also carry a rating of the size of fire the extinguisher should be able to extinguish. This figure is given in relation to the size of test fires.
Types Of Fire Extinguishers: Wet, Dry And Gas
As a general rule, extinguishers come in two formats; liquids or non-liquid alternatives.
Water fire extinguishers and water additive are the most common types you will see in a business environment, and these are particularly suitable for Class A fires. The additive version (also known as Hydrospray) is more popular because the additive makes it more powerful and enables smaller extinguishers to be used such as 3 litre and 6 litre. It also has the special nozzle that makes it safe if accidentally sprayed onto live electrics.
Foam fire extinguishers are normally the AFFF (Aqueous Film Forming Foam) type of extinguisher, which seals the fire with a foam film to extinguish the flames. It is suitable for use on Class A and B fires, and the modern spray nozzle makes it safe for accidental use on electrical equipment.
Carbon Dioxide or CO2 fire extinguishers which is the commonly used in Nigeria ,its 'dry' extinguishers, and therefore suitable for fires involving electricity and electrical equipment, and Class B fires.
Dry powder fire extinguishers are the best all-rounder extinguisher for areas with a variety of fire risks (but not offices, shops, hotels and similar) as the multi-purpose and ABC versions can be used on Class A, B and C fires, and fires involving electrical equipment. Standard or ‘BC’ powder is still in use with Monnex being the best known but this is not suitable for Class A fires.
Wet Chemical fire extinguishers are for Class F fat and oil fires, but can also be used on Class A fires.