Fire requires oxygen, heat, and fuel to burn in a process called the fire triangle. Fires can be classified and different methods and agents are used to extinguish them. Common fire extinguishing agents include water, foam, dry chemical powder, and carbon dioxide, each suited to different fire classes. The PASS method outlines the proper technique for using a portable fire extinguisher by pulling the pin, aiming at the base of the fire, squeezing the lever, and sweeping from side to side.

1. BASIC FIRE SCIENCE AND FIRE
EXTINGUSING MEDIA &
TECHNIQUES.
BY
PRATHAP M D
SECURITY PROFESSIONAL

2. AGENDA
• Fire triangle
• Transmission of heat-Conduction, Convection and Radiation
• Classification of fire
• Sources of ignition
• Methods to extinguish fire-Starvation, Smothering, Coiling and
Inhibition
• Fire extinguishing agents-Water, Foam, CO2, Dry chemical, Dry
powder, Fire blanket.
• Types of fire extinguishers and color coding.
• Fire extinguishing technique using portable fire extinguisher-PASS.

3. FIRE
F-Find the fire locality.
I-Inform everyone pulling the MCP,Calling command center etc.
R-React immediately-Isolating burning material from the scenario, decide what
type of fire and decide what type of extinguisher to be used
E-Extinguish the fire with right fire extinguisher

4. FIRE TRIANGLE
FIRE IS THE CHEMICAL REACTION BETWEEN THREE ELEMENTS SUCH AS
Oxygen, Heat and Fuel.
Oxygen-Its common in the atmospheric air.
Heat- A source of ignition sufficient to initiate and propagate the chemical
reaction of combustion. Heat travels though conduction, convection and
radiation
Fuel-Combustible substances in the for of vapor, liquid or solid. Examples-
Wood, Paper, Petroleum products, Plastic, combustible gas etc.

5. IGNITION TEMP,FLASH POINT, FIRE
POINT.
IGNITION TEMP : The min temp at which fuel will ignite without help of
ignition source. it also called "auto ignition temp".
FLASH POINT : The min temp at which the rate of vaporization of fuel is
sufficient to produce a momentary flash upon the application of source
of ignition.
FIRE POINT : The min temp at which the burning vapor is capable to
enable combustion continue.

6. TRANSMISSION OF HEAT
Transmission of heat happens through Conduction, Convection and
Radiation
• Conduction-Conduction usually happens in solid. Heat transfers from
one molecule to another molecule of the metal is called conduction.
Example for conductive metals are Copper, Aluminum, Brass, Steel,
Bronze etc.

7. • Convection-Convection happens in liquid only. When water is
heated it becomes less denser and low denser water moves down to
replace less denser water causing a circular motion is called
convection.
Example:-Boiling water on stove, Radiators etc.

8. • Radiation-Radiation is energy travelling through space. Sunshine is
the most familiar for of radiation. The Radiation refers to the
emission of energy in rays or waves. Heat travels in a straight line.
Sometimes radiation travels through glass windows and concentrate
on one object inside the building and cause fire. Below is the best
example for radiation which causes Fire.

9. CLASSIFICATION OF FIRE
1. CLASS A (SOLID FIRE)- Ordinary combustible such as wood, paper,
cloth, trash and plastics.
2. CLASS B (LIQUID FIRE)- Flammable liquids such as gasoline,
petroleum oil, alcohol, varnish and paints.
3. CLASS C (GASEOUS FIRE)-Flammable gases like propane, butane,
hydrogen, Gasoline and natural gases.
4. CLASS D (COMBUSTIBLE METALS)-Sodium, Potassium , Magnesium,
lithium and titanium.
5. CLASS E (ELECTRICAL FIRE)-Short circuits, electrical equipment,
electrical shocks, improper wirings etc.
6. CLASS F (COOKING OILS)- FAT, GHEE, OILS USED FOR COOKING ETC.
In US system class B and C is combines and called as Class B. In Australian/European system B and C is separated. In US
system class C is called Electrical fire and in Aus. Eurp called as Class E.

10. SOURCES OF IGNITION
OPEN FLAME ELECTRICAL SPARK HOT GASES
HOT SURFACES CHEMICAL REACTION MECHANICAL SPARK
WELDING SMOKING BATTERIES

11. METHODS TO EXTINGUISH FIRE
1) STARVATION-Removal of fuel by cutting fuel supply.
Examples
Removal of surrounding combustible materials
Turning off a gas supply
Blanking of a pipeline
Turning off petroleum pipe lines.

12. 2) SMOTHERING-REMOVAL OF OXYGEN.
Examples
Covering a blanket or wood to prevent small fire in a drum.
Smothering a frying pan blaze with a fire blanket
Covering a candle with a glass
Covering a waste bin with fire blanket to prevent oxygen supply.
Closing the doors of the closed cabins.
Using CO2 and DCP extinguishers.

13. 3) COOLING-REMOVAL OF HEAT.
Cooling the burning material is the most common method used in
extinguishing fire involving solid materials.
Examples
Using water type (CO2 CARTRIDGE TYPE)
Water stored pressure type-using hydrant system
Water bucket

14. 4) INHIBITION-STOPPING THE CHAIN REACTION
Some extinguishing agents such as dry chemical powder interrupt the
flame producing by cutting off the chemical chain reaction of the
substance. Which can be used for Class B and C FIRE.
DCP extinguishers puts out fire by coating the fuel surfaces with
chemical powder. This separates the fuel from the oxygen in the air and
prevent vapor formation. The powder also interrupts the chemical chain
reaction of fire.

15. FIRE EXTINGUISHING AGENTS
1)WATER-Water is the most common extinguishing agents used for A
type fire or solid fire. Water can be used in portable fire extinguishers
through hydrant system, sprinkler system also used by fire brigades.
Water extinguish the fire by taking away the heat element of the fire
triangle, which is called as cooling. Water should not be used on Class B
and Class C fire. It will spread the flammable liquid in class b fire and
create shock hazard on class C fire.

16. 2) FOAM-A fire fighting foam is simply a mass of small air filled bubbles,
which have lower density than oil, gasoline or water. Foam is made up of
three elements such as water, foam concentrate and air. When mixed
these three elements form a foam blanket. Foam separates the flames
source from the fuel surface. By applying foam we can extinguish the
fire by smothering that is taking off the oxygen from the fire triangle.
Foam extinguishers are used for Class B fire.

17. 3) CARBON DIOXIDE-Carbon dioxide is a non-conductive and non
corrosive gas used to reduce the amount of oxygen available to the fire.
Carbon dioxide is extracted from the atmosphere and stored at high
pressure in the liquid state within a fire extingushers.Carbon dioxide is
suitable for Class B(flammable liquids) and Class C (electrical fire).
Carbon dioxide mainly extinguish the fire by smothering that is taking
out the oxygen supply in fire triangle.

18. 4) DRY CHEMICAL- The Dry Chemical Extinguisher removes the chemical
reaction of a fire. In this category the multi-purpose Dry Chemical
extinguisher is the most used fire extinguisher of all extinguishers
because it is effective on Class A, Class B and Class C fires. This is an
excellent fire extinguisher because it creates a barrier between the
oxygen and fuel elements on Class A fires. Dry Chemical Extinguisher and
not a multi-purpose Dry Chemical extinguisher, only use it on Class B and
Class C fires.

19. 5) DRY POWDER- Similar to the dry chemical extinguisher, dry powder
separates fuel from oxygen or removes the heat element of a fire. Dry
powder extinguishers are used on Class D (combustible metal fires) only.
They will not be effective on any other type of fire class. Dry powder
mainly extinguish the fire by inhibition method.

20. 6) FIRE BLANKET-A fire blanket is a highly flame-resistant blanket that
can be used to extinguish a small fire or to wrap around a person in case
of a fire. Fire blankets are made from 2 layers of woven glass fiber fabric
and an inner layer of fire retardant film. They work by cutting off the
oxygen supply to the fire. Mainly fire blanket uses the method of
smothering in extinguishing fire.

21. TYPES OF FIRE EXTINGUISHERS AND
COLOR CODING
TYPE CLASS COLOR CODING IMAGE
WATER A (SOILID) RED
FOAM A(SOLID) & B(LIQUID) CREAM
CO2 B(LIQUID) ,E
(ELECTRICAL)
BLACK
DRY POWDER A, B C , BC or D BLUE

22. FIRE EXTINGUISHING TECHNIQUE USING
PORTABLE FIRE EXTINGUISHER-PASS
1) Pull the pin. Every fire extinguisher has a pin inserted into the handle that
prevents the fire extinguisher from being discharged by accident. Grab the ring
and pull the pin out from the side of the handle.
2) Aim the hose at the base of the fire. Hold the lower handle lever (the
carrying handle) with one hand and grab the hose or nozzle with the other
hand. Point the hose directly at the base of the fire, because you have to put
out the fuel that’s burning. Do not aim the hose at the flames.
3) Squeeze the lever. To release the extinguishing agent, squeeze the two
levers together with one hand while you aim the hose at the base of the fire
with the other. Apply slow and even pressure when you squeeze the levers
4) Sweep the hose from side to side. To extinguish all the fuel, slowly sweep
the hose back and forth over the base of the fire as you discharge the
extinguisher. Move closer to the fire as the flames die down