Bs bab 2

C3001 / UNIT 2 / 1FIRE PREVENTION AND PROTECTION

General Objective : To understand a systematic introduction to fire behavior,

prevention and control

Specific Objectives :

At the end of this unit you should be able to:

• identify the causes of fire.

• describe the types of fire prevention equipment and the system.

• understand the fire prevention rules.

• identify fire prevention symbols in building plans.


2.0 INTRODUCTION

What is a fire ?

Fire are the largest accidental killer in Malaysia,

behind motor vehicle accidents, falls, and drowning.

It is also a disaster that families are mostly likely to

experience. Over 80 percent of all fire deaths occur

where people sleep, such as in homes or hotels. Most

fires occur when people are likely to be less alert

such as in homes or hotels and as between midnight

and morning. 84 percent of house and building fires

are accidental, such as those caused by poor

electrical wiring or negligence. However, 16 percent

are set intentionally through arson or acts of

terrorism.


DID YOU KNOW?

Fires in buildings are nearly always man – made, resulting from error or

negligence. Primitive man used heat for cooking, warming and lighting his dwelling with

the inherent risk that misuse or accident in his control of fuel might precipitate disaster.

Today as in primitive society, that risk has not been eliminated despite the

apparent sophistication of modern living. With the development of habitation, attitudes to

fire protection or fire precautions also developed, sometimes subtly, but mostly from

bitter experience. The principal aims of fire precautions are simply to safeguard life and

property.

A fire extinguisher is a portable device used to put out fires of limited size. Such

fires are grouped into four classes, according to the type of materials that is burning.

Yes….I understand now, this unit will explore

the causes for the spreading of fire…I should

make a list of all I have to read today.


WHAT CAUSES A FIRE?

Fire is a chemical reaction involving rapid oxidation or burning of a fuel. It needs three

elements to occur.

OXYGEN – The air we breathe is about 21 percent oxygen. Fire only needs an atmosphere with at least 16 percent oxygen

HEAT- Heat is the energy necessary to increase the temperature of

the fuel to a point where sufficient vapors are given off for ignition

to occur.

CHEMICAL REACTION – A chain reaction can occur when the

three elements of fire are present in proper conditions and

proportions. Fire occurs when this rapid oxidation or burning takes

place.

Take any one these factors away, and a fire will not occur or will

be extinguished if it was already burning.

FUEL – Fuel can be any combustible material – solid, liquid or gas.

Most solids and liquids become a vapor or gas before they burn.


2.1 Preventing The Causes For The Spreading Of Fire

a) Conduction

This is a process in which thermal energy can transfer through a solid or liquid that is

under the influence of a thermal stress or gradient. In most building materials it is a

molecular process by which the thermal energy can travel like a sound wave along a

solid. However, in the metallic material this energy transfer is caused by electron

movement within the solid material.

In building materials there are up to three distinct modes of energy transfer possible,

these being:

i- Thermal conduction by atomic and molecular vibration

• The ease at which thermal energy can be transferred down a rod or

other structure depends on the type of bonding between the molecules.

• The materials that have a rigidly-bound structure pass more energy

than those with a weakly – bound structure.

• This is due to the fact that the frequency of vibration for rigidly

molecules is high, thus the rate at which the energy is transferred is

also high. The energy is transmitted down the road by very-high-

frequency elastic waves.


• These waves can be compared to sound waves, but have much higher

wave frequencies.

• The quantum of energy associated with such wave motion is called the

phonon, which is passed from molecule in turn all the way down the

length of the rod.

• In an insulation-type material, the conduction process is dominated by

these waves and their phonon-lattice framework collision processes.

• So, if the interaction between phonons increases, as it must do with an

increase in temperature, this will cause the thermal conductivity.

• Most masonry materials are polycrystalline, that is they consist of

more than one crystal type, and since the phonons are scattered by

crystal boundaries and by porosity it is not surprising that such

materials have a lower phonon-conductivity than the single-crystal

type.

• The situation of an amorphous type material, such as glass, is one in

which the phonon-scattering process dominates thus making the

conductivity of an amorphous material independent of temperature for

practical purposes.

ii- Thermal conduction due to radiation

• Radiation passes through solids and undergoes scattering at structure

imperfections, crystal boundaries and at pores. In a highly porous


• material this type of conductivity can be shown to be proportional and

become quite significant at temperatures above 500 C.

• However, in opaque-type materials this type of conductivity only starts

to become important at 1000 C or above.

iii- Thermal conduction due to mass transfer ( gaseous conduction )

• In this case a gas, such as air, which fills the pores within the material,

can add to the ability of the material to pass heat energy through the

material under a thermal gradient or by a buoyancy effect.


Figure 2.1 : Thermal conduction routes within a building

structure

b) Radiation

This physical process unlike conduction or convection does not require a mechanical

medium to enable energy to be transferred from a hot radiant surface to a combustible

material.

Radiation, which may be in the ultra-violet, visible or heat radiation (infra-red) range,

is an electromagnetic wave.

Figure 2.2 : Sketch of rectangular radiations surface for work


c) Convection

The convection process plays a very important role in the spreading of fire

throughout a building since approximately 76 – 80 per cent of energy released from a

fire is by this process. In simple terms when a heat source is introduced to a fluid as

shown in figure 2.3 and 2.4.

Figure 2.3 : Hot layer of gas forming at

ceiling level

Figure 2.4 : Radiation feedback

from hot gas layer at ceiling to

combustible materials below

Layer of gas close to ceilingLayer of hot gas


Questions

1. How does a fire start?

2. List the causes for the

spreading of fire?

3. What is a conduction

process?


Answer

1. Fire is a chemical reaction involving rapid oxidation or

burning of a fuel. It needs three elements to occur.

• Fuel - fuel can be any combustible material, example solid, liquid or gas. Most solids and liquids become a vapor or gas before they burn.

• Oxygen – The air we breathe is about 21 percent oxygen. Fire only needs an atmosphere with at least 16 percent oxygen.

• Heat – heat is the energy necessary to increase the temperature of fuel to a point where sufficient vapors are given off for ignition to occur.


Answers

The causes are

• conduction

• radiation

• convection

3. Conduction is a process in which thermal energy can transfer through a

solid or liquid that is under the influence of a thermal stress or gradient. In

most building materials it is a molecular process by which the thermal

energy travels like a sound wave along a solid.

However, in the metallic material energy transfer is caused by electron

movement within the solid material


2.2 Type Of Fire Prevention Equipment And The System

Fires are caused by the different materials, and thus classified into 4 categories:

CLASS A

Ordinary combustibles or fibrous material, such as

wood, paper, cloth, rubber and some plastics

HOW ARE FIRES

CLASSIFIED?


CLASS B

Flammable or combustible liquids such as

gasoline, kerosene, paint, paint thinners and

propane .

CLASS C

Energized electrical equipment, such as

appliance, switches, panel boxes and power

tools

CLASS D

Certain combustible metals, such as magnesium,

titanium, potassium and sodium. These metals burn

at high temperatures and give off sufficient oxygen

to support combustion. They may react violently

with water or other chemicals, and must be handled

with care.


Class A – Ordinary combustibles:

Class B – Flammable liquids or gases:

Keep storage and working areas free of trash. Place oily rags in

covered containers.

Don’t refuel gasoline-powered equipment in a confined space, especially in the presence of an open flame such as a furnace or water heater.

Don’t refuel gasoline-powered equipment while it’s hot.

Keep flammable liquids stored in tightly closed, self-closing, spill-proof containers. Pour from storage drums only what you’ll need.

Store flammable liquids away from spark-producing sources

Use flammable liquids only in well-ventilated areas.

HOW ARE FIRES

PREVENTED?


Class C – Electrical equipment

Look for old wiring, worn insulation and broken electrical fittings. Report any hazardous

conditions to your supervisor.

Prevent motors from overheating by keeping them clean an in good working order. A

spark from a rough-running motor can ignite the oil and dust in it.

Utility light should always have some type of wire guard over them. Heat from an

uncovered light bulb can easily ignite ordinary combustibles.

Don’t misuse fuses. Never install a fuse rated higher than specified for the circuit.

Investigate any appliance or electrical equipment that smells strange. Unusual odors can

be the first sign of fire.

Don’t overload wall outlets. Two outlets should have no more than 2 plugs.

Class D-Flammable metals:

Flammable metals such as magnesium and titanium generally take a very hot heat source

to ignite. However, once ignited they are difficult to extinguish as the burning reaction

produces sufficient oxygen to support combustion, even under water.


In some cases, covering the burning metals with sand can help contain the heat and

sparks from the reaction. Class D extinguishing agents are available (generally as dry

powder in a bucket or box) which can be quite effective, but these agents are rare on the

campus.

If you are planning a research project using a large amount of flammable metals you

should consider purchasing a five or ten pound container of Class-D extinguishing agent

as a precaution.

Pure metals such as potassium and sodium react violently (even explosively) with water

and some other chemicals, and must be handled with care. Generally these metals are

stored in sealed containers in non-reactive liquid to prevent decay (surface oxidation)

from contact with moisture in the air.

White phosphorus is air-reactive and will burn / explode on contact with room air. It must

be kept in a sealed container with a non-reactive solution to prevent contact with air.

All of these metals are not uncommon in labs on the OU campus, but are generally only

found in small quantities. An accidental fire / chemical leading to a fire reaction can be

controlled or avoided completely through knowledge of the properties of the metals and

using good judgment and common sense.

HOW TO EXTINGUISH

SMALL FIRES ?


Class A - Extinguish ordinary combustibles by cooling the

material, below its ignition temperature and soaking the fibers to

prevent re-ignition. Use pressurized water, foam or multi-purpose

(ABC-rated) dry chemical extinguishers. DO NOT USE carbon

dioxide or ordinary (BC-rated) dry chemical extinguishers on class

A fires.

Class B - Extinguish flammable liquids, greases or gases by

removing the oxygen, preventing the vapors from reaching the

ignition source or inhibiting the chemical chain reaction. Foam,

carbon dioxide, ordinary (BC-rated) dry chemical, multi-purpose

dry chemical, and halon extinguishers may be used to fight Class B

fires.


NOTE: Multipurpose (ABC-rated)

Class D - Extinguish combustible metals such as magnesium,

titanium, potassium and sodium with dry powder extinguishing

agents specially designated for the material involved. In most

cases, they absorb the heat from the material, cooling it below its

ignition temperature.

Class C - Extinguish energized electrical equipment by using an

extinguishing agent that is not capable of conducting electrical

currents. Carbon dioxide, ordinary (BC-rated) dry chemical,

multi-purpose dry chemical and halon* fire extinguishers may be

used to fight Class C fires. DO NOT USE water extinguishers on

energized electrical equipment.

* Even though baton is widely used, EPA legislation is phasing it out

of use in favor of agents less harmful to the environment.


Chemical extinguishers leave a residue that can harm sensitive equipment, such as computers

and other electronic equipment. Because of this, carbon dioxide or halon extinguishers are

preferred in these instances because they leave very little residue. ABC dry powder residue is

mildly corrosive to many metals. For example, residue left over from the use of an ABC dry

powder extinguisher in the same room with a piano can seriously corrode piano wires. Carbon

dioxide or halon extinguishers are provided for most labs and computer areas on campus.

REMEMBER……….

Remember the acronym, "P.A.S.S."—

P ......Pull the Pin.

A …...Aim the extinguisher nozzle at the base of the

flames.

S …Squeeze trigger while holding the extinguisher

upright.

S ......Sweep the extinguisher from side to side,

covering the area of the fire with the extinguishing

agent.

HOW TO USE A PORTABLE

FIRE EXTINGUISHER?


• Should your path of escape be threatened

• Should the extinguisher run out of agent

• Should the extinguisher prove to be ineffective

• Should you no longer be able to safely fight the fire

THEN LEAVE THE AREA IMMEDIATELY!

1. Know the locations of the fire extinguishers in your work area.

2. Make sure the class of the extinguisher is safe to use on fires likely to occur in the

immediate area.

3. Check the plastic seal holding the pin in the extinguisher handle. Has the

extinguisher been tampered with or used before? Report any broken/missing

seals/pins to the Fire Safety Unit.

4. Look at the gauge and feel the weight. Make sure the extinguisher is full.

HOW DO YOU CHECK YOUR

FIRE EXTINGUISHERS?


Water, some foam, and dry chemical extinguishers have gauges indicating the pressure

inside the extinguisher. The pressure needle should be in the "green" area (generally100-175

Ibs, depending on the type of agent).

CO2 (carbon dioxide) extinguishers are high pressure cylinders with pressures ranging from

1500 lb to 2150 Ib. These extinguishers DO NOT have gauges and must be weighed by fire

Safety Unit staff to determine the amount of contents remaining.

NOTE :Ib and Ibs = pounds

5. Make sure the pin, nozzle and nameplate are intact.

6. Report any missing, empty or damaged fire extinguishers to the Fire Safety Unit

whenever you notice any discrepancies.

2.2.1 Description Of Fire Extinguishers: How Do They Look Like?

Generally, you can tell at a glance which type an extinguisher is hanging on the

wall, or in the cabinet, just by looking at its shape. Check the labels of the extinguishers

in your area and note the color and shape/size of the extinguisher. This may help if

someone runs in to help you fight a fire with the WRONG extinguisher (i.e. water on an

electrical fire) - you can STOP them before they are injured or make matters worse!

ABC-rated multipurpose dry powder extinguishers are the most

common on campus, particularly in the corridors of academic buildings.

They are almost always RED in color and have either a long narrow

hose or no hose (just a short nozzle). These extinguishers are very light

(5-25 Ibs total weight).Halon extinguishers look virtually identical to

ABC multipurpose dry chemical extinguishers.


Water extinguishers are generally only found in the dormitories and are

usually SILVER (crome-metal) in color, have a flat bottom, have a long

narrow hose, are quite large (2-1/2 gallons). Foam extinguishers (rare on

the OU campus, nowadays) look similar and the type without gauges

have a handle inset in the flat bottom (you turn the extinguisher upside

down to start and use it)

C02 (carbon dioxide) extinguishers are generally red (often

yellow around aircraft or on military sites), have a LARGE

"tapered" nozzle (horn), are VERY HEAVY (15-85 Ibs.)Some

CO2 extinguishers for aircraft hangers or special industrial use

are so large as to require roll-around carts to move them. These

are all high-pressure cylinders.

Care should be taken not to drop a CO2 cylinder; if it is

damaged it may be able to make a hole through the nearest

wall(s) and end up on the other side of campus! (The

containers are quite sturdy, but don't abuse them.) 002

cylinders do not have a pressure gauge – they must be weighed

to determine the amount of contents


• In the corridors of academic and office buildings, and inside very large rooms

• In or immediately outside all laboratories where chemicals are stored and used

• In or immediately outside mechanical spaces where motorized or other equipment

is present which might reasonably cause a fire

• In campus airpark hangers, storage buildings, and mounted inside certain university

vehicles

WHERE can I find a fire extinguisher on campus?

Questions

State whether the following statement are TRUE or FALSE

1. Do not use carbon dioxide or ordinary dry

chemical extinguishers on class A fires.

2. Class A fires are fueled by ordinary

combustible or fibrous material, such as

wood, paper, cloth and some plastics.

3. Class D fires can be extinguished with

water.



Answers

1. True

2. True

3. False


2.3 Fire prevention rules

People protect themselves from the dangers of fires in several ways. Fire

extinguishers in homes enable people to put out fires before they become dangerous,

while smoke detectors alert residents that a fire has broken out in the early stages.

Hundreds of Malaysians die in home and building fires each year, but most of

these deaths could be avoided. Make sure your family knows simple fire-prevention rules

and what to do if a fire does strike.

Most fire victims die from inhaling smoke and poisonous gases, not from burns. If

you know how to recognize danger signs and how to act appropriately, you will increase

your chances of getting safely out of a burning building.

2.3.1 Fire – Safety Procedure

Have a plan set in advance. All rooms in your house should have two means of

escape. Draw a picture showing the escape routes for every room and explain it to

everyone.

Upper floor windows should have hook-on fire escape ladders or rope ladders.

Assign one older person to be responsible for each child. Plan on a meeting place

outside.


Have practice fire drills every three months, especially if there are small children or

disabled persons in your home. Some of your drills should take place at night.

All members of the family should know how to call 911 to give the house address and

tell the person on duty that there is a fire.

2.3.2 Warning From The Smoke Detector Alarms

Act immediately but try to stay calm. Wake up anyone who may still be asleep, and

shout, "Fire! Everyone out!" Don't waste time getting dressed or searching for valuables.

Once outside the house, do not go back in.

Sleep with bedroom doors closed. Doors offer protection from heat and smoke and slow

a fire's progress. If in your escape you must go from room to room, close each door

behind you.

Feel every door before opening it. Place the back of your hand on the crack between the

door and the door frame; if it's hot, do not open the door. Even if the door is cool, open it

cautiously. Stay low in case smoke or toxic fumes are seeping around the door. If heat

and smoke come in, slam the door tightly and use alternative exits.

If you use a window for your escape, be sure the door in the room is closed tightly.

Otherwise, the draft from the open window may draw smoke and fire into the room.

If you must go through smoke, crawl under it on your hands and knees. However, do not

crawl on your belly, because some heavier toxic gases settle in a thin layer on the floor.

If you are unable to escape from a room because of a fire on the other side of the door,


stuff clothing, towels, or newspapers in the door's cracks to keep smoke out of your

refuge.

Remember "STOP, DROP, ROLL" if your clothing catches fire. The moment it

happens, stop where you are. Drop to the ground, and cover your mouth and face with

your hands to protect them from the flames. Then roll over and over to smother the

flames.

2.3.3 High Rise Apartments

If you live in a high rise apartment there are a few added things you should know in case

there is a fire in your building:

Learn your building's evacuation plans. Know the location of fire alarms, and learn how

to use them. Post emergency fire department numbers near all telephones.

If you hear instructions on your building's public-address system, listen carefully and do

just as you're told.

Never take an elevator when leaving a burning building. Instead, go directly to the

nearest fire- and smoke-free stairway.

If you cannot get to a fire stairway, go to a room with an outside window.

If there is a working phone, call the fire department emergency number and tell the

dispatcher where you are. Do this even if you can see fire trucks on the street below.


Stay where rescuers can see you through the window, and wave a light-colored cloth

such as a hand towel to attract their attention.

If possible, open the window at the top and bottom. Be ready to shut the window quickly

if smoke rushes in.

You may need to be patient; the rescue of occupants of a high-rise building can take

several hours.

2.3.4 Building Regulations

The current set of building regulations have their origin in Post-War Building

Studies and the objectives, although never expressly stated, have experienced a subtle

change of emphasis in order to remain relevant to a modern social and industrial

infrastructure. In this chapter it is intended to discuss the philosophy of the current

prescriptive building regulations.

DO YOU KNOW WHAT

BUILDING REGULATIONS

ARE?


Building regulations assume that if certain components of fire safety can be

identified and suitable standards applied to particular building types, a satisfactory level

of fire safety will be achieved.

There is no evidence to support this assumption. Indeed, some would argue that

the available evidence points in the opposite direction. Generally the structure of building

regulations follow the pattern developed below:

1. Classify buildings by type

2. Compartment buildings

3. Prescribe fire resistance requirements for elements of structure

4. Limit unprotected areas of external walls

5. Prescribe constructional requirement for separating walls, compartment walls and

floors.

6. Prescribe constructional requirements for protected shafts

7. Specify the type and constructional requirements for fire-resisting doors

8. Control the penetration of fire barriers by services

9. Specify non-combustibility requirements for stairways in prescribed situations

10. Describe requirements for cavity barriers and fire stops

11. Control spread of flame over walls and ceilings

12. Control the use of plastics on ceilings

13. Relate the sitting of buildings to roof constructional requirements.


2.4 Fire Prevention Symbols In Building Plan


SOURCE: BUILDING AND FIRE T.JSHIELD & G.W.H.SILCOCK LONGMAN SCIENTIFIC

& TECNICAL


Questions

1. What would you do if someone is on fire?

2. What would you do if you are trapped in a building

which is on fire?


Answer

1. In situation when a person is on fire :

STOP - where you are

DROP - to the floor

ROLL - around on the floor


Write the best answer for each of the following questions:

2. These are the steps that you need to follow:

• Act immediately but try to stay calm

• If you use a window for your escape, be sure

the door in the room is closed tightly.

• If in a dorm room, use wet towels to seal the

space under the door and prevent the entry

of smoke.


1. How do you use a portable fire extinguisher?

2. How are fires classified?

3. How are fire extinguishers classified?

Mistake shows us what we need to learn


1. Remember the acronym “ P. A .S . S ”

P………..Pull the pin

A……….Aim the extinguisher nozzle at the base of the flames

S………..Squeeze trigger while holding the extinguisher upright

S………..Sweep the extinguisher from side to side, covering the area of the

fire with the extinguisher agent

2. The 4 classes of fires are :

• Class A – caused by ordinary combustible liquid such as gasoline,

kerosene, paint thinners and propane.

• Class B – caused by flammable or combustible liquids such as gasoline,

kerosene, paint thinners and propane.

• Class C – caused by energized electrical equipment, such as appliance,

switches, panel boxes and power tools.

• Class D – caused by certain combustible metal, such as magnesium,

titanium, potassium and sodium. These metal burn at high temperatures

and give off sufficient oxygen to support combustion.

• They may react violently with water or other chemicals, and must be

handled with care.


3. Fire extinguishers are classified by the size and class of the fire; they are

designed to extinguish fires. Different extinguishing agents are used for

different classes of fire.

Pass" and "fail" are the

old ways of explaining

how much you know. The

new ways are, "knowledge

and "ignorance".

Date post:	14-May-2015
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