Make sure you get the right extinguisher and that you know haw to use it, what its limitations are and what the resultant effects of the extinguisher will be. Here are some points about fighting fires and each of the main extinquisher types.
The Triangle of Fire. Fire needs three elements to exist.
1 Fuel (solids, liguids or gases)
2 Heat (various materials will spontaneously combust a different temperatures) although ather surces af ignition acn trigger a fire, the heat of which will then be self sustaining.
3 Oxygen (you need oxygen to burn with the fuel, some fuels have their own source of oxygen eg plastic explosives)
remove any one of the above elements and the fire can not live. Different extiguishers work by removing different elements of the fire.
Water suitable for category A fires (Paper wood and textiles) NOT FOR ELECTIRCAL FIRES. Extinguishes fires by removing the heat element. The standard 9 litre (the size most commonly found in workplaces) water extinguishers will last for about 60 seconds. The jet of water will spray about 10 feet.
CO2 (carbon dioxide) suitable for category B fires (flammable liquids) and electrical fires. Using a CO2 extinguisher will put out the fire by depriving the fire of oxygen. If you are in an enclosed space like a tent or a caravan it will quickly replace all the oxygen in that space, this means you will not be able to breath. Never spray onto bare skin as this will cause a frostbite burn. Never hold the nozle or base of the extinguisher as these will also getr extremely cold and can cause frostbite burns. A standard 2kg size (size found in an office) will last for 8 seconds.
ABC Powder (Dry Powder) Suitable for category A (Paper wood and textiles), B (Flamable liquids), C (Flammable gases) electrical fires and vehicle protection. Works by removing the oxygen, smothers the fire. The powder is an irritant and will cause problems for people with dermatitis (spelling?) and breathing problems such as bronchitus or asthma. If using in an enclosed space the powder will not disperse and can cause visibility problems and breathing problems.
Foam Spray suitable for category A (paper wood and textiles) and B (Flammable liquids) and vehicle protection. this works in much the same way as a water extinguisher but has a foaming agent added which effectively makes the water wetter. this also has the added bonus of making the extinguisher capable of smothering a fire (removing the oxygen) aswell as cooling the fire. Because it foams, it increases the surface area of the water, this makes it much more effective at cooling the fire.
Halon (green canister) these are now illegal although they were very good extinguishers they were very harmful to teh environment.
None of these extinguishers are suitable for cooking oils and deep fat frier fires. these require the use of a fire blanket, or a wet chemical extinguisher. DO NOT PUT WATER ON A COOKING FAT FIRE. I'm sure you've all seen the very scary consequenses of this.
My personal preferance would be for the Foam Spray, not suitable for electric fires but then i don't have EHU.
Post last edited on 02/06/2005 13:33:41
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Topic: Fire Extinguishers
