workplace safety 3220 chapter 3.2 fire protection

Workplace Safety 3220Workplace Safety 3220

Chapter 3.2

Fire Protection

3.2 Fire Protection3.2 Fire Protection

In this chapter you will understand:

Why fires occur, and

How to properly apply the procedures used to

Prevent,

Detect and

Extinguish fires

3.2 Fire Protection3.2 Fire Protection

Work-related fires have killed hundreds of people in this country and injured thousands of others.

Many fires are caused by the unsafe acts of people through carelessness and a lack of knowledge.

What they all have in common is that they are Preventable.

Fire prevention is Everyone's Responsibility.

The Chemistry of FireThe Chemistry of Fire

For a fire to occur, 4 components are necessary:

Fuel

Oxygen

Heat

Chemical ChainReaction

Common Causes of FireCommon Causes of Fire

Smokers Materials

CigarettesMatchesOpen Flame

Electrical

FusesShort CircuitsOverlaoded CircuitsLoose Connections

Misuse of Flammable Liquids

Fat FiresOily Rags

ExplosionsExplosions

An explosion is

A very rapid, contained fire occurring when the gases produced by the fire exceed the pressure capacity of the container.

A simple example is a firecracker:

1.The fuse burns into the centre of the firecracker.

2.The powder inside ignites and burns very rapidly, producing gas.

3.The paper wrapper cannot withstand the pressure and blows apart.

ExplosionsExplosions

Controlling FiresControlling Fires

Knowing how and why fire burns suggests ways to control it.

Fire can be controlled in the following ways:

By cooling the burning materials

By removing oxygen

By removing fuel

These methods interrupt the chemical chain reaction.

Heat TransferHeat Transfer

Heat always moves from higher temperatures to lower temperatures.

Heat from a fire is transferred to other objects in 3 ways:

Conduction: direct heat transfer through solids and liquids in contact with each other.

Radiation: electromagnetic wave transfer of heat to a solid. Eg. Heat and light from the Sun

Convection: heat transfer through the movement of hot gases.

Types of Heat TransferTypes of Heat Transfer

Spontaneous CombustionSpontaneous Combustion

This can occur when organic compounds decompose and release flammable gas. This leads to a buildup of heat and can result in a fire.

In nature, such as in forests and swamps, gas and heat are vented naturally and fires are rare.

If oily rags are stored in a closed container, heat buildup can cause the oil to vapourize. This creates a potentially dangerous hazard. Propercontainers are required.

Classification of FiresClassification of Fires

Fires are classified according to the types of materials being burned.

Class A FireClass A Fire

Ordinary materials

Wood, paper, garbage

Class A fires are extinguished by the quenching and cooling effects of water.

Class B FireClass B Fire

Flammable or combustible gases and liquids.

Gasoline, kerosene, propane, grease, paint thinner, paint, oil.

Water will spread the fire. Use dry chemicals, CO

2, or

foam.

Class C FiresClass C Fires

Energized electrical equipment.

Appliances, power tools, switches.

Do not use foam or water (they conduct electricity).

Use dry chemicals or CO

2.

Class D FiresClass D Fires

Combustible metals.

Titanium, magnesium, sodium, potassium, phosphorous*.

Do Not use normal extinguishing agents of Class D fires. It can make them more intense. Use only specialized techniques, agents and equipment.

Fire PreventionFire Prevention

Fire PreventionFire Prevention

Practise Good Housekeeping:

Keep work area free of clutterClean flammable dust regularly (sawdust)Wipe up spills of flammable liquidsKeep fire exits and exit routes clearNever use alcohol or gasoline as a cleaning

agentStore flammable waste in proper containersStore flammable liquids properlyExtinguish cigarettes in proper containersObey all “No Smoking” signs

Fire PreventionFire Prevention

Avoid Electrical Hazards

Don't overload circuitsDiscard frayed or worn cordsCheck for problems with electrical equipment

OverheatingFaulty switchesExposed wires

Never use a tool or extension cord if the grounding plug has been removed.

Fire PreventionFire Prevention

Be careful handling flammable, combustible, and explosive materials

Flammable – materials that catch fire and burn easily and give off intense heatLiquids – gasoline,

acetoneSolids –

phosphorous, magnesium, sodium

Gases – propane, acetylene, hydrogen

Fire PreventionFire Prevention

Combustible – materials that will burn under ordinary circumstances because of an outside source

paper, wood, cloth

Fire PreventionFire Prevention

Explosive - materials such as dynamite, nitroglycerin, blasting caps, metal powders, plastic powders, even dust.

Fire PreventionFire Prevention

Keep flammable, combustible, and explosive material away from sources of heat or friction.

Never refuel a hot or running engine

Clean up spills immediately

Look out for empty containers that once held flammable materials

Flammable, combustible, and explosive materials must be properly labelled

Fire PreventionFire Prevention

Minimize the potential for a dust explosion

Can occur when a spark comes in contact with sawdust, mill dust, or other finely divided particles.

Fire PreventionFire Prevention

Be aware of possible ignition sources

FlameCigarettesStatic electricitySparksWeldingFurnacesHot ashHeating elementsElectrical switches

Responding to a FireResponding to a Fire

Know the locations of fire alarms

Know the locations and operation of fire extinguishers

Be aware of the nearest fire exits

Know evacuation procedures

Know where to gather after evacuation

Know the company's procedure for reporting a fire

Escape and Muster PlansEscape and Muster Plans

Industrial FiresIndustrial Fires

Try to eliminate the causes of fires:

Use only approved equipment

Establish Safe Work Practises

Enforce good housekeeping procedures

Train workers to spot hazardous conditions and report them immediately.

Industrial FiresIndustrial Fires

Develop Fire Protection Programs

Design buildings with fire protection in mind

Enforce regular inspections

Train employees in detection, alarms, evacuation, preventing, confining, and extinguishing a fire.

Fire DetectionFire Detection

Fire detection devices include:

Human observers

Automatic sprinklers

Smoke, flame, heat, CO

2, and CO

detectors

Fire DetectionFire Detection

The 2 main tasks of fire detection are:

To give an early warning to allow building occupants to escape

To give an early warning to fire-fighting teams to prevent or minimize losses

Fire DetectionFire Detection

Building should be equipped with fire detection systems that do 2 important things:

Communicate to all where the fire is located

Summon appropriate fire-fighting units.

When an alarm is sounded, all employees must know what the sound means.

A building can have different alarms for different emergencies