What you Must Know about Classification of Dangerous fire

What you Must Know about Classification of Dangerous fire
Classification
of fire(part2)

Fire are classified
into 4 categories according to the types of materials involved.

Class
description
Mode
of extinction
“A”
Fires
involving solids and free burning material usually of an organic nature
e.g. wood, paper, textile, furniture, etc they are domestic in nature. They
generally leave an ash.
Cooling
by application of water.
“B”
Fires
involving flammable e.g. P.M.S., D.P.K., A.G.O., cooking oil, wax, paints,
spirits, varnish, etc.
It
also includes flammable gases, e.eg. LPG, propane, natural gases,
acetylene, etc.
Starvation
by cutting off the supply. Smothering by application of a suitable cover.
Us e of foam or DCP.
“C”
Fires
involve electrical/energized equipment. As long as it is plugged in, it is
considered a class C fire.
Starvation
by cutting off the supply and/or allow to burn out. Use CO2   extinguisher.
“D”
Fires
involving special metals, e.g. potassium, sodium, calcium, magnesium,  copper, zinc, etc.
Smothering  by the use of special fire fighting dry
chemical e.g. T.E.C.(temary – eutectic – chloride) and sodium bicarbonate.
Metal  X foam. Alternatively, use dry
sand cement etc.
Electrical fires;
It is considered
that electricity does not constitute a class of fire because electricity is a
source of energy.
 Is normal procedure is to isolate the
electricity and use fire extinguisher on the burning material. Only when this
cannot be done with certainty will special extinguishing agents be required
which are non-conductors of electricity and non-damaging to equipment: these
include dry power and carbon dioxide, although the latter’s cooling and
condensation effects may damage sensitive electronic equipment. Never use
water on electrical equipment, as water is good conductor of electricity
shock or electrocution may result if water is used on live electricity
equipment.
Extinguishers colour
coding 
 Colours have been allocated for all
portable fire extinguishers for  ease
of identification.
–         
 Carbon-dioxide (CO2)                                   black
–         
Dry chemical power                                       blue/red
–         
Foam                                                               cream
–         
Water/gas                                                       red
Advantages of
portable fire extinguishers
1.     
They are light in
weight.
2.     
One person is
required at a time.
3.     
They are
instantaneous in action.
4.     
They are reliable if
well maintained.