What is Fire?
What is Fire?
A chemical reaction that
involves the evolution of
light and energy in
sufficient amounts to be
perceptible.
What are the ingredients
needed to make fire?
What are the ingredients
needed to make fire?
What are the ingredients
needed to make fire?
What are the ingredients
needed to make fire?
What are the ingredients
needed to make fire?
What are the classes of
fire?
What are the classes of
fire?
“A”, “B”, “C”
“D” “E” & “K”
Class “A” fire
• Classification of fire
involving ordinary
combustibles such as wood,
paper, cloth, plastics, and
rubber.
Class “B” fire.
• Classification of fire
involving flammable and
combustible liquids, gases,
and greases. Common
products are gasoline, oil,
alcohol, propane and
cooking oils.
Class “C” fire.
• Classification of fire involving
energized electrical equipment,
where the electrical
nonconductivity of the
extinguishing media is of
prime importance.
Class “D” fire
• Classification of fire
involving combustible
metals and alloys such as
magnesium, sodium, lithium
and potassium.
Class “E” fire
• Classification of fires involving
nuclear materials. Due to
radioactive contamination,
smoke from fires involving
nuclear materials may
produce more harm than the
fire itself.
Class “K” fire
• Classification of fire that
involves fires in
combustible cooking
fuels such as vegetable
or animal oils and fats. In
the kitchen
Fire Extinguishers
Class “A”
• Water is used in a cooling or
quenching effect to reduce
the temperature of the
burning materials below its
ignition temperature.
Class “A”
• Water can also be used to
suffocate the fire by creating
steam which displaces the
oxygen needed for
combustion.
Class “B”
• The most effective method
of extinguishing this type of
fire is to smother with foam
or to remove the fuel.
Class “B”
• Another method of
extinguishing is temperature
reduction which can be
accomplished by applying
water fog.
Class “C”
• These fires can sometimes
be controlled by a nonconducting extinguishing
agent such as Halon, dry
chemical, or carbon dioxide.
Class “C”
• The safest method of
control is to first de-energize
the circuit then treat as the
class of the fuel involved.
Class “D”
• There is no single agent
that will control or extinguish
fires in all combustible
materials.
Class “D”
• Water is ineffective and may in
fact cause more harm. Hitting
some class “D” fires with water
will cause them to explode and
burn hotter.
Class “D”
• Certain metals will continue
to burn until they have
exhausted the fuel supply.
Ratings of Fire
Extinguishers
 Class “A” and “B”
extinguishers are rated by
the size fire they should be
able to put out.
Ratings of Fire
Extinguishers
Class “C” and Class “D”
extinguishers are only labeled
for the materials they
extinguish.
Ratings of Fire
Extinguishers
• Class “D” extinguishers are
also labeled to indicate the
specific metal they are to be
used on.
Ratings of Fire
Extinguishers
• Class “A” ratings are 1A to 40A.
• A 1A extinguisher contains 1 ¼ gallons or
5 L of water… A rating of 2A contains 2 ½
gals or 10 L
• A dry chemical extinguisher with a 10-A
rating is equivalent to five 2 ½ gal.
extinguishers.