Element-7 Fire Safety

Element-7

Fire Safety

1.      The common fire hazard in the workplace

2.      Fire prevention and control

3.      Fire risk assessment

This element focus on fire safety as it applies to low risk working environments and general principles of fire risk management.

On completion of this element you should able to :

1.      Outline the common fire hazard in the workplace

2.      Identify the benefits of fire risk assessment and the matters which should be address when undertaking a basic fire risk assessment.

3.      Outline the basic principles of the prevention and fire control in the workplace

What is Fire?

Fire is a chemical reaction of three elements they are fuel, oxygen and heat.

 

                                            Oxygen                     Heat

                                                             Fuel

For a fire, there condition must exist at the same time. There must be:

1.      Fuel that will burn.

2.      An Ignition source to initiate and sometimes sustain the fire until it can sustain itself by the further release of heat energy.

3.      Presence of source of oxygen.

Taking away one of these elements of the fire triangle will means that the fire will be prevented or will be stopped (Extinguished).

Hazards of Fire

Main Effects:

1.      Being burnt

2.      Inhaling toxics fumes

3.      Effects of smoke inhalation

4.      Reduction of oxygen supply

Other Effects

1.      Collapse of building

2.      Crush or other injury sustained while escaping.

General Cause of Fire

1.      Arson:  Arson is a crime of intentionally and merely setting fire to building, wild lands areas, vehicle or other property with the intent to cause damage.

2.      Electrical faults

3.      Misuse of electrical equipment

4.      Smoking in prohibited areas

5.      Loss of control burning rubbish

6.      Heating equipment

7.      Unsafe storage of materials

8.      Flammable liquids/ gases

9.      Welding/ hot work

10.  Mechanical heat (friction)

Main cause of Fire

1.      Sources of ignition

2.      Source of fuel

3.      Source of oxygen

Source of Ignition

1.      Naked flames from heaters smoking etc.

2.      Electricity (over heating/ Arcing)

3.      Spark from metal grinding

4.      Hot work (welding and cutting tools)

5.      Smoking materials

6.      Chemicals reaction (giving of heat)

7.      Heating appliances (hot surfaces)

8.      Friction (insufficient lubrication)

9.      Lightning

10.  Static electricity

11.  Improper storage of flammable materials

Sources of Fuel

1.      Wood, plastic, foam, furniture, paper etc.

2.      Flammable liquids such as petrol some solvent.

3.      Dust from coal, wood, scrap and food stuff.

4.      Gasses like hydrogen which may be generate as part of work process such as a battery charging etc.

Sources of Oxygen

1.      The most common source of oxygen is the air around us

2.      Cylinders certain chemicals, called oxidizing substance provide a source of oxygen when they are heated or react with other chemicals

3.      Oxidizing agent such as hydrogen peroxide and sodium hypochlorite etc.

Principal causes of the spread of fire

1.      Conduction

2.      Convention

3.      Radiation

4.      Direct burning

Conduction:  Heat will transfer between neighboring molecules of a substance thus transfer always takes place from a region of higher temperature to the region of lower temperature and occurs in solids, liquid and gases are very poor conductors of heat.

Convention: When air become warm it became less dense and begins to rise colder more dense air will in turn be drawn down to the fire brining a fresh source of oxygen.

Radiation: Radiation is a transfer of heat from an object to its surroundings in the form of electromagnetic wave.

Direct burning: This is simply the action of materials catching fire from direct contact with other burning materials.

Flash Point and Fire Point

Flash Point: This is the lowest temperature at which the vapor given off by a substance will burn when brought in contact with source of ignition.

Fire Point: When the fire is reached to sufficient gas or vapor is being given of to sustain a flame when in contact with a source of ignition.

Flammable and Auto Ignition

Flammable: liquids with a flash point between 32° centigrade and 55° centigrade.

Highly Flammable: Liquids with a flash point below 32° centigrade.

Auto ignition temperature: This is the temperature at which gases or vapor will ignite without any external source of ignition.

Classification of Fire

Class	Type of Fuel
A	Combustible solids
B	Flammable liquids or liquefied solids
C	Flammable gases
D	Flammable metals
F	Cooking and fat
Fire involving electrical equipment	Electrical: classified according to the source of ignition rather than fuel source.

Types of Extinguisher

Class	Type of Extinguisher
A	Water, dry powder, foam
B	Foam, co2, Dry powder
C	Dry powder, water, Foam
D	Sand, soda ash, talc
F	The foam congeals on the top of the oil
Electrical	Co2, dry powder

Extinguishing Agents

Type	Color code	Fire class	Performance
Water	Red	A	Cool the fuel and surrounding
Dry powder	Blue	All	Smother the fire
Foam	Cream	B	Smother burning liquids
Co2	Black	All	Cools and exclude oxygen
Cooking oil/ fats	Canary yellow	All	Cools and exclude oxygen
Fire blanket	None	B	Smother the fire

Fire Extinguisher

Water: class A

1.      Drop the ignition temperature

2.      Prevent re ignition

3.      Not safe to use on fire involving electricity

4.      Not suitable for combustible liquids, cooking fats etc.

5.      Suitable for use on class A fires, wood, paper, plastic etc.

6.      Extinguishes by cooling

7.      Red body

Foam: Class B

1.      Eliminates oxygen – blanket effects

2.      Aqueous film forming form

3.      Suitable for class A&B fires

4.      Not suitable for use on fires involving electricity

5.      Extinguishes by cooling and sealing surface of a burning liquid.

6.      Cream body (old type) or red body with cream label.

Dry powder: Class A, B,C

1.      Can be used on all type of fire.

2.      Powder has a smothering effects but not cooling properties

3.      Blue body (old type) or red body with blue label.

4.      Best on class B fires but safe to use on any type of fire.

5.      Work by chemically interfering with the burning reaction.

Carbon dioxide: Class B, E

1.      High pressure cylinder containing liquefied co2

2.      Safe to use on electrical fires and burning liquids.

3.      Black body (old type) or red body with the black label.

4.      Best on class B and C fires but safe to use on any type of fire.

5.      Safe to use on fires involving electricity.

6.      Extinguishes by reducing oxygen level and cooling.

Fire Safety at Home

1.      Fit and maintain the smoke detector

2.      Check round at night

3.      Close doors at night

4.      Don’t smoke in bed

5.      Prepare an escape plan

Fighting a Fire with Extinguisher

Do not fight the fire if:

1.      It is bigger than waste paper bin

2.      One extinguisher is not enough

3.      Smoke is affecting your breathing

4.      You cannot see the way out

5.      Gas cylinders or chemicals are involved

6.      Your effects are not reducing the size of the fire.

Fire Blanket

·         Any color body or label but they are usually red or white

·         Extinguishes by smoking

·         For use on any type of fire but best on small contained class B fires and people on fire.

Inspection and Maintenance of Fire Extinguisher

Inspection: Routine (perhaps monthly ) visual checks to ensure extinguishers are in place, not been discharged or damaged.

Maintenance: Involves an annual examination by a competent person with the removal and replacement of equipment found faulty and out date of the inspection recorded.

Fire Extinguisher Maintenance

1.      Daily Checks(fire men)

2.      Weekly inspection (fire warden)

3.      Annually checked (competent person)

4.      Five yearly extended service / discharge

5.      Twenty yearly overhaul/ replacement.

Extinguishing Fire

1.      Cooling the fire by removing the heat

2.      Starving the fire of fuel

3.      Smothering the fire by limiting the oxygen supply.

Fire Precaution, Prevention and Protection

1.      Fire precaution (Happening of fire)

2.      Fire Prevention (Starting)

3.      Fire protection(Spreading)

Fire Precaution:

1.      Fire/Smoke detection

2.      Fire alarms

3.      Means of escape

4.      Means of fighting the fire

5.      Emergency evacuation procedures

Fire Prevention:

1.      Eliminate or reduce the storage of flammable materials

2.      Control of ignition sources

3.      Control smoking materials

4.      Good House keeping

5.      Lubrication of machinery to prevent friction

6.      No overloading of electrical system

7.      Regular inspection of electrical system

8.      Ventilation outlets not obstructed

9.      Controlling hot work with permit etc

10.  Proper storage of flammable materials

11.  Segregation of incompatible chemicals

12.  Security to prevent arson

13.  Regular inspection and supervision

Fire protection:

Compartmentation: (Compartmentation is probably the most effective means of limiting fire damage)

Splitting a building into separate sealed areas made of fire resistance materials.

Restricts the spread of fire and smoke within the building depends upon

·         Use of building

·         Building height

·         Floor area

·         Compartment volume

Minimizing Risk Of Electrical Fire

1.      Pre – inspection by user

2.      Suitability of equipment

3.      Inspection / maintainance by competent person

4.      Avoid misuse of equipemtn

5.      Prevent overloading of circuits

6.      Isolate if not in use

7.      Using better quality of RCD

8.      High standards of house keeping

9.      Staff awareness training

Means of Escape: A means of escape is continuous paths along which a person can travel from where ever he / she may be in the building and reach safety by his own an aided efforts.

Emergency Evacuation

1.      Means of raising the alarm

2.      Contacting the emergency services

3.      Fire evacuation routes and signs

4.      Role of fire marshals

5.      Assembly point / place of safety / roll call

6.      Types of extinguishers use

7.      Prevention of spread of fire eg: slosing fire doors

8.      Not to use of lifts

9.      Excavation in an orderly method

10.  Prevention of return

11.  Disable evacuation procedures.

Suitability of Escape

1.      Number of employees to use it

2.      Any people with special needs

3.      Fire resistance of structure

4.      Position/ number of escape routes

5.      Content which are readily combustible / flammable

6.      Open wells, open stair cases

7.      Use of building

Practice Drill

Practice drills should be undertaken to:

1.      Satisfy legal requirement E.g. Fire certificate

2.      Provide instruction to employees on action to be taken

3.      Checking alarm can be heard though out the premises

4.      Testing the effectiveness of the evacuation procedures

5.      Familiarizing employees with the alarm etc.

6.      Giving fire warden to practice their roles.

Fire Risk Assessment

1.      Identify Hazard: The three elements of the triangle of fire

2.      Identify who could be harm: Person at risk particularly the disable etc.

3.      Evaluate the risk and adequacy of precautions: considering prevention, protection and precautions.

4.      Record finding: record the significant finding’s plane, informs, instruct and train, including having a plan to deal with the emergencies.

5.      Review: review the assessment as and when necessary.

Factors to Consider in Fire Risk Assessment

1.      Construction and use of building

2.      Flammable materials

3.      Source of ignition

4.      Work activities generating heat

5.      Methods of control

6.      Means of fire detection

7.      Means of raising alarm

8.      Means of fire fighting/ maintenance of equipment

9.      Evacuation routes/ protection of routes

10.  Number of person at risk

11.  Fire prevention training / fire drills

Role of Fire Marshalls

1.      Fire marshals normally supervise a fire evacuation and take charge of as emergency until the emergency service arrives.

2.      They will make sure the alarm has been sounded and the emergency service noticed

3.      They may fight the fire if it is safe to do so

4.      They may make a roll call, often from the visitor and staff sign in and records to ensure everyone has escape and make a search of the premises. This should be done it is safe to do so.