There are several types of extinguishers and several types of fires:
WATER: For wood/paper/textile fires only.
FOAM: For wood/paper/textile fires and flammable liquids.
CARBON DIOXIDE (CO2): For flammable liquids and live electrical equipment fires.
POWDER: For wood/paper/textile fires, flammable liquids, flammable gases, live electrical equipment fires.
WET CHEMICAL: For cooking oil fires and wood/paper/textile fires.
FIRE BLANKET: For kitchen fires e.g. chip-pan fires, and clothing fires e.g. wrapping around somebody whose clothes are on fire.
None of the above extinguishers should be used on flammable metals e.g. magnesium, sodium, potassium. Such fires are especially dangerous, and should be extinguished by specialist extinguishers by specially trained personnel.
Although water, foam and wet chemical extinguishers should not be used directly on live electrical equipment, some of them have passed an electrical conductivity test, which gives the operator greater safety when tackling fires in the vicinity of live electrical equipment.
As a general rule, fire protection firms fit certain types of extinguishers in certain areas:
In general office areas, double fire points comprising a water or foam extinguisher for your wood/paper/cloth fires, and a carbon dioxide extinguisher for your electrical equipment fires.
Rooms containing significant quantities of live electrical equipment e.g. computers, photocopiers, switchgear, servers, lift and other electrical machinery, are protected with carbon dioxide extinguishers.
Rooms containing gas supplies or cylinders e.g. boiler rooms and propane gas compounds, are protected with powder extinguishers.
Kitchens with hot-oil cooking facilities are protected with wet chemical extinguishers and fire blankets.
Areas containing flammable liquids e.g. petrol, oil, spirits, are protected with a powder, foam or carbon dioxide extinguisher or a combination of these.
We supply pocket guides showing a simple chart, from which you can easily find out what type of extinguisher can be used on what type of fire. Also, we fire identification signs above each extinguisher that clearly state what fires that particular extinguisher should and shouldn't be used on. Contact us if you would like a supply of any of these -they are supplied free of charge to all attendants of any of our training courses.
When choosing which extinguishers to install in a premises, an assessment has to be made not only of the fire risks, but of the type of premises it is, and the potential users (and potential abusers) of the extinguishers. For instance, although the powder extinguisher can be used on several types of fires, it does create severe dust and mess if used, that can be expensive and time-consuming to clear. It can also cause damage to some equipment and machinery. Now I appreciate that fire will also do extensive damage, and from one point of view, any dust/mess from a powder extinguisher that has stopped a premises burning down is a price well worth paying! However, on frequent occasions, people can and will discharge extinguishers by accident, or maliciously, or as a prank. If a powder extinguisher was discharged in this situation, you may find yourself having to evacuate your premises as the rooms fill with a cloud of dust, shutting down the area or whole premises whilst you employed professional cleaners, and spending your time and money sourcing replacement computers etc that the powder has damaged. If your premises was a restaurant, hotel, care home, night-club, you can only imagine the dreadful impact this could have on your business, even if your insurance covered the cost. All for the sake of an extinguisher being let off. My personal opinion is that it is often better to install a combination of clean extinguishers in a premises e.g. a foam one for wood/paper fires, and a CO2 one for live electrical equipment fires. Of course, there are areas that HAVE to be protected by powder extinguishers, which we certainly would do. I am by no means saying that powder extinguishers are not excellent for extinguishing certain fires in certain situations. I am just warning you of some of their disadvantages that you might not have thought of before purchasing one.