Fire extinguishers are mandatory safety equipment in all workplaces. The quantity and type of fire extinguisher depends on the size of the building and nature of work being performed on site or materials being used. There is no one fire extinguisher to put out all fires. Using the incorrect fire extinguisher may cause more harm than good.
In order to determine the type or class of fire extinguisher required it is necessary to distinguish between the various types of fires one may be at risk of in the workplace as there are four classes of fires, these are:
- CLASS A – ORGANIC FIRES: these are ordinary solid flammable materials such as coal, paper, plastic and wood.
- CLASS B – FLAMMABLE LIQUIDS: these are fires where flammable liquids, lubricants and gasses are present such as alcohol, benzene or oils.
- CLASS C – ELECTRICAL FIRES: energised electrical source serves as the igniter of a Class A, B or D fire. If the electrical source is removed it is no it is no longer a Class C fire.
- CLASS D – METAL FIRES: sodium, aluminium, lithium, etc.
In South Africa there are five different types of fire extinguishers and each are used to combat various types of fires.
- Dry Chemical Powder (DCP) Fire Extinguisher
- CO2 Fire Extinguisher
- Wet Chemical Fire Extinguisher
- Water Fire Extinguisher
- Foam Fire Extinguisher
ABC Powder fire extinguisher or better know in South Africa as a DCP fire extinguisher is a multi-purpose fire extinguisher and is therefore one of the most common extinguishers. The fire extinguisher can be used on Class A, B or C fires, hence the name ABC Powder extinguisher.
CO2 fire extinguishers were originally designed for Class B fires and are being used for fire fighting on live electrical equipment. Commonly installed next to a foam extinguisher in server rooms that have a lot of computers inside. CO2 is also one of the cleanest types of extinguishers that leaves no residue and require no cleanup afterwards. These fire extinguishers can be used on a Class B or C fire.
Water extinguishers are only suitable for Class A fires, used on another class of fire may result in an explosion.
Foam fire extinguishers comprise of pressurised foam and are ideal for multi risk situations where Class A and B fires are likely to be found as a direct hazard.
Class D fires require their own specialised fire extinguisher. If flammable metals are being used or stored then a Wet Chemical fire extinguisher is required. The extinguisher has a dry powder agent that absorbs heat and smothers the flames.
Prepared by Maryke Jonker – 07.08.2020