Types of fire, Uses, Types of fire extinguisher, Uses, Do's and Don'ts of fire extinguishers along with their pictures

1. Name : Muhammad Hamad Qureshi
Roll Number: D-19-CH-61
Topic : Fire and fire extinguisher
Department : Chemical engineering
Institute : Dawood UET, Karachi.

2. Types of fire:
Fires can be classified in six different ways depending on the agent that fuels them.
Types of fire Type of fire extinguisher used to cut off each fire
Class A: They involve solid materials
like wood, paper, plastic, or clothing.
 Extinguish with water.
 Foam fire extinguisher.
 Dry powderExtinguisher.
 Wet chemical Extinguisher.
Class B: Fires involving flammable
liquids like oil, paint, petrol.
gasoline, alcohol etc.
 Dry powderExtinguisher.
 Foam fire extinguisher.
 Carbon dioxide extinguishers.
The last two type of extinguishers work by cutting off a fire's
oxygen supply.
Class C: Fires involving flammable
gases like butane, propane.
 Dry powder.
Class D: fires involving burning
metals like aluminum, magnesium,
titanium etc.
 Class D fires are oftentimes
caused by alkali metals such as
potassium, magnesium,
aluminum, and sodium, as these
can ignite when exposed to air or
water.
 It requires high level of heat to
ignite metal, so this type of fire is
rare
 Dry powder extinguishers
Dry powder extinguishers work on metal fires by separating
the fuel from oxygen or removing the heat element of the blaze.
Class E: Fires involving electrical
equipment’s.
 It might be started by old wiring
in walls, frayed electrical cords,
worn-out breaker boxes, or
faulty appliances.
 Carbon dioxide extinguishers.
 Dry powder extinguishers.
CO2 extinguishers are ideal for places with a lot of electrical
equipment.
Dry powder can also be used on fires involving electrical
equipment however, they do not cool the fire so it can re-ignite.
It can also create a loss of visibility and may create breathing
problems. They are not generally recommended for use inside
buildings unless there is absolutely no alternative.

3. Class F: Fires involving cooking oil
and fats.
 Becauseof the high flashpoint of
cooking oils and fats, Class F fires
often start when a pan is left
unattended for too long on a
stove.
 Wet Chemical Extinguisher.
 Water Extinguishers:
Water extinguishers are mostly used
for class A fire risk. They involve solid
materials like wood, paper, plastic, or
clothing. As far as the inner workingis
concerned, a water extinguisher works
by having a cooling effecton the liquid
that causes the burning fuel to burn at
a slower rate until the flames are
completely extinguished.
 All water extinguishers have a red
label.
 Don’t usedfor:
o Fire involving flammable liquids
o Fire involving Electrical equipment’s
o Kitchenfires

4.  Foam fire extinguisher:
Foam extinguishers are some of the
best for liquid fires, such as gasoline
fires, but can also be used on Class A
fires involving solid combustibles like
wood.
Theyspray a type of foam that expands
whenithitsthe air and blanketsthe fire.
Thisblanketpreventsthe vaporsfrom
risingoff the liquidtofeedthe fire,thus
starvingitof fuel.Also,becausethe foamis
mixedwithwater,ithasa coolingeffectas
well.
 All fire foam extinguisher have a cream
label.
 Don’t usedfor:
o Fire involving Electrical equipment’s
o Kitchenfires
o Fires involving metals
 Dry Powder Extinguishers:
Powder extinguishers are a good multi-
purpose fire extinguisher because they can
be used on Class A, B and C fires. They can
also be used on fires involving electrical
equipment however, they do not cool the fire
so it can re-ignite. They are not generally
recommended for use inside buildings unless
there is absolutely no alternative.
 Powder extinguishers have a blue label.
 Don’t usedfor:
o Make sure it is not uesd inside
the buildings(closedair) because
it can cause loss of visibility and may create breathing problems.
o It is also not used for electrical equipment over 1000 V.

5.  Carbon Dioxide (CO2)
Extinguishers:
CO2 extinguishers are ideal for places
with a lot of electrical equipment’s.
They also put out Class B fires. CO2
extinguishers suffocate fires by
displacing the oxygen the fire needs to
burn. CO2 extinguishers work by
smothering the fire and cutting off the
supply of air.
 This type of extinguisher has a black
label.
 Don’t used for:
o Kitchenfires
o Fires involving metals
o Solidmaterial involving wood, paper etc.
 Wet Chemical Extinguishers:
Wet chemical extinguishers are suitable
for use on Class F fires involving cooking
oils and fats, such as lard, olive oil,
sunflower oil, maize oil and butter. They
are extremely effective, when used
correctly. The wet chemical rapidly
knocks the flames out, cools the burning
oil and chemically reacts to form a soap-
like solution, sealing the surface and
preventing re-ignition.
 Wet chemical extinguishers have a
yellow label.
 Don’t usedfor:
o Flammable liquids and gas fires
o Fire involving Electrical equipment’s

6. o Fires involving metals