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CHAPTER 3FIRE SAFETY

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INTRODUCTION

Incidence of fire may occur in workplaces where there are:

a) Ongoing work processes such as welding, cutting, spray painting and grinding works.

b) Confined spaces where there are flammable chemicals or oxygen content of over 23.5 %

c) Faulty equipmentd) Storage areas/ warehouse where there are flammable materials

or where the process of oxidising occurs.

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Causes ofFIRE

a) Short circuitb) Equipment failure such as valves and safety devicesc) Welding activities, cutting of metals, grinding worksd) Overflow/ leakages of flammable liquid or gasese) Overheatingf) Contact with hot surfacesg) Leakage or failure of pipesh) Human factor such as intentional burning.

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Factors contribute to the incident of

FIRE

a) System failure such as fire sprinkler, smoke detectorb) Insufficient water supply for the spraying systemc) No spraying systemd) Operator/ human errore) Existence of flammable materialsf) Breakage/ explosion of containers containing flammable

materials

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Basic ofFIRE

Fire can be defined as:

“ A chemical reaction that occurs when a flammable material and oxygen comes into contact with a heat source or ignition”

What the means????

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FIRETriangle

Flam

mab

le

mat

eria

l

Oxygen

Heat

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Oxygen

• Fire requires oxygen in its initiation, occurrence and continuation

• Source of oxygen is the air- Combination of 78 % Nitrogen, 21 % Oxygen and1% other gasses such as carbon dioxide and argon.

• Also come from various chemicals that may encourage fire

• These chemicals called agents of oxidisation . Eg hydrogen peroxide.

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Heat :• Usually known as the source of ignition.• Form of energy that upon contact with oxygen and flammable

will start a fire.

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Burning process• The occurrence of fire releases a form of energy that provides

the source of energy for it to continue burning and release heat.

• Vapour or gas may ignite due to sparks or small flames while solid and liquids require 2-5 % more heat and oxygen.

• To reach the self ignition temperature that may cause fire, a flammable material requires only a small flame.

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CLASSES OF FIRE

Fire Class Material Type Example Agent

A Normal flammable Wood, paper, fabric, plastic

Water, dry chemical, foam

B Flammable liquid and gas

Gasoline, oil, grease, LPG

CO2, foam, dry chemical, halon

C Working electrical item Electric motor CO2, dry chemical, halon

D Metal flammable Magnesium, sodium, pottasium

Dry chemical powder

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FIRE HAZARD CONTROLS

Fire hazard may be controlled by:

a) Fire preventioni) Avoiding surge of flammables into the atmosphereii) Releasing of heatiii) Controlling of heat sources ( Fire triangle )

b) Fire protectioni) Releasing of heatii) Enclosing or stopping supply of flammableiii) Enclosing or stopping supply of oxygen

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Employer has to first formulate a safety plan as follow:

a) Hazard identification through:i) HAZOP – Hazards and Operability studiesii) Hazard checklistiii) Fire and explosion indexiv) Chemical exposure index

b) Safety plan such as:

Selection of safe technology: Safe materials, equipments,machineries, and processes includes user- friendly workplace, environmentally safe technology and safe storage system

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c) Safety prevention system

i) Prevention of initial incident: detection and monitoring system, safe handling procedure and engineering controls.

ii) Stop/ control the source of hazard a soon as the incident happens: Extinguishing of fire, reducing supply of flammable, dilution, emulsion, reducing oxygen content, disrupting the burning process and reactions.

d) Safety protection system: Provides protection during fire occurrence by stopping spread of fire.

i) Fire wall/ barrier to air flowii) Fire resistance isolator- isolate fireiii) Trap fire to prevent explosioniv) Layout of tank and equipments

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e) Emergency response plan

i) Hazard identification and risk assessmentii) Control methodiii) Communication – Incident Command System ( ICS )iv) Announce and update emergencyv) Cooperation of external partiesvi) Public relations

f) Medical treatment

i) Medical surveillance and treatment system includig - Sending victims to medical center if exposed to :• Toxic materials from fire• Heat

ii) Ensure procedures for:- Transportation of victims- Appointment of officer in charge

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Safe Storage

Fire wall

Slope to hole

Storage tank

Hump

Fire hole

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Storage tank

Hump

Safe Storage

Hump

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SAFETY PLANSelection of Safe Technology

Characteristic User-friendly

Substitution of CHEMICALS Avoid fire

Weakening of HAZARDOUS CHEMICALS

De-fridgerate atmospheric temperatureDilution

Design of EQUIPMENT Reaction may be handled and control Strong and suitable

Plant LAYOUT Break spread of fire and isolate between equipments.

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SAFETY PLANAdministrative and

Engineering Controls

Administrative Controls Engineering Controls

On the job training programme Better equipment

Instruction and written procedures Improved layout to minimised work hazard

Signages Location of valve, switch and instruments

Labelling of equipment Design of equipment – user friendly

Suitability of person to job Better manual handling method

Testing Decentralised computer control

Classroom teaching Design of equipment- able to prevent/ control mistake

Warning Online analysis

Incentive and punishment Online parameter assessment

Persuasion method to promote safe work

Practices

Inspection

Review

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The end