Firstly : Why does a fire happen?
Fires are caused when 3 things are present at the same time - a source of combustible material, heat & ignition and oxygen.
Removal of one of these is the basis of all FIRE PREVENTION & CONTROL.
OXYGEN can be cut off in several ways
In the case of a chip pan fire, a Fire Blanket is placed over the burning pan and excludes oxygen - take it off too early and the fire will start again!!!
A Blue Fire Extinguisher covers the burning material with powder and stops oxygen getting to it - the powder itself can be a problem if it gets into the workings of such fine electrical items as computers, printers and photocopiers.
A Black Fire Extinguisher substitutes the air with Carbon Dioxide and this 'crowds out the oxygen' - once the carbon dioxide floats away, the oxygen returns and the fire can restart!!
HEAT & IGNITION is controlled in the classic way by applying water with a Red Fire Extinguisher or Fire Hose to cool the fire - plenty of water cools the fire to a level it cannot go on burning.
If put on burning oil however, the oil floats to the surface and continues to burn, the water can act as a carrying agent and the fire can spread - that is why it should not be used on an oil fire.
To get over this , the Cream Fire Extinguisher contains water mixed with an additive which, when sprayed over the fire, forms a film forming foam - this has the advantage of cooling the fire as well as cutting off the oxygen supply.
On an electrical fire, water would cause problems of electrocution and so Blue or Black Fire Extinguishers are used.
HALON gas (a green coloured extinguisher) used to be used for fire extinguishers but is not now 'Environmentally Friendly' and once used will not now be replaced. Black Fire extinguishers are used instead.
There are new European Standards for Fire Extinguishers which mean that all Fire Extinguishers are to be coloured red with a disc on the side, colour coded as before indicating its contents.
This will only apply to new fire extinguishers. Existing Fire extinguishers do not have to be changed.
These is usually controlled by planning & good housekeeping - where have you placed the store? - are cans left lying around? - is smoking allowed in that area? - are there flammable liquids? - is there electric heaters?
It can be very dangerous to use the wrong extinguisher and it is part of your RISK Assessment that you identify the type of fire likely to occur and the best type of control to have.
SMOKING is one of the main sources of naked flames in a workplace - you must think seriously what you are going to do about it:
Keep everything clean and tidy:
Smoke or heat alarms must be placed correctly and checked by competent operators.