Fires are probably one of the most common emergencies that we all must plan for. A fire can be made worse by the incorrect use of a fire extinguisher and so this guide will show you how to use your extinguishers both safely and effectively. There are four steps to using an extinguisher correctly:
- Pull the pin
- Aim low towards the base of the fire
- Squeeze the handle
- Sweep nozzle from side to side at base until fire has been extinguished.
Fire extinguishers are not meant for tackling large fires. It is important that you know when to evacuate should the fire become too large to handle, or the environment too dangerous.
The three most common portable fire extinguishers are air-pressurised water, carbon dioxide, and multi-purpose. Using the incorrect fire extinguisher for the job can end up making things a lot worse. Always check that the needle on the gauge is in the green, if not, you won’t have enough pressure to put the fire out.
- Air pressurised water – these should only ever be used on Class A fires such as wood, paper, cloth, rubber, and some plastics.
- Carbon dioxide – these are designed for Class B fires only such as oil, some paints, grease, solvents, and other flammable liquids. Along with Class B, these can also be used on Class C fires such as electrical fires.
- Multi-purpose extinguishers – usually marked as ABC, these can be used safely on all the above and work by coating the fuel element with a layer of fire-retardant powder.
Evacuation procedures should be followed when any of the following signs are present.
- Fire has become too large – the fire involves flammable solvents, is partially hidden behind a wall or ceiling, cannot be reached from a standing position, or covers more than 60 square feet in area.
- The air has become unsafe – if the levels of smoke make fighting the fire impossible without a respirator.
- Environment becomes too hot – if the heat levels make it impossible to get close enough to use the fire extinguisher effectively. Crawling on the floor can help avoid the heat and smoke.
- Evacuation paths have become impaired – The fire is not contained and heat, smoke or flames block potential evacuation routes.
So, remember the pass procedure should you ever need to use a fire extinguisher.
- Pull the pin and hold the extinguisher with the nozzle pointed away from you, then release the locking mechanism.
- Aim the nozzle down to the base of the fire.
- Squeeze the handle slowly.
- Sweep the nozzle from side to side.
Never turn your back on a fire, even when you think that it has been extinguished. A fire can reignite without warning if there are any hot spots that have been missed.
Choosing the Right Fire Extinguisher
When it comes to choosing a fire extinguisher, you must first know what type of fire you are dealing with. Not all fire extinguishers can be used on all fires and if you get it wrong, it can be fatal.
Fires are split up into 6 categories (classes) which are:
- Class A – fires fuelled by solids such as paper, wood and plastic
- Class B – fires fuelled by flammable liquids such as paraffin, petrol and oil (not cooking oils)
- Class C – fires fuelled by flammable gases such as propane, butane and methane
- Class D – fires fuelled by metals such as aluminium, magnesium and titanium
- Class E – fires involving electrical apparatus
- Class F – fires fuelled by cooking oils and fats
For any fire to start and survive, there needs to be three elements present; heat, oxygen and fuel. These three elements make up what is known as the fire triangle. Remove any one of these elements and the fire will be extinguished.
Oxygen is the easy part as it is all around us in the air that we breathe. Heat sources is the ignition such as from smoking or electrical equipment. The fuel is anything that burns such as paper, solvents and flammable gases.
Dry powder extinguishers remove the oxygen from the fire triangle and are safe to use on all common types of fires, including electrical. The biggest problem with dry powder is the mess left behind so they are not recommended for use in confined spaces.
Carbon Dioxide or CO2 gas extinguishers are clean and leave no mess behind. These also remove the oxygen from the fire triangle and are suitable for using on Class B, flammable liquid and electrical fires.
Water removes the heat from the fire triangle and is ideal for Class A flammable solids like wood, paper and fabrics. These kinds of extinguishers should never be used on electrical fires or fires involving flammable liquids like petrol or solvents.
AFFF is a great multipurpose extinguisher that can be used for Class A flammable solids and especially effective on Class B flammable liquid fires. These create a film layer over the top of burning liquid, removing the oxygen from the fire triangle and smothers the flames