Workplace Safety 3220

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Workplace Safety 3220

• Chapter 3.2
• Fire Protection

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3.2 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

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3.2 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.

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The Chemistry of Fire

• For a fire to occur, 4 components are necessary
• Fuel
• Oxygen
• Heat
• Chemical Chain
• Reaction

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Common Causes of Fire

• Smokers Materials
• Cigarettes
• Matches
• Open Flame
• Electrical
• Fuses
• Short Circuits
• Overlaoded Circuits
• Loose Connections
• Misuse of Flammable Liquids
• Fat Fires
• Oily Rags

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Explosions

• 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
• The fuse burns into the centre of the
  firecracker.
• The powder inside ignites and burns very rapidly,
  producing gas.
• The paper wrapper cannot withstand the pressure
  and blows apart.

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Explosions
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Controlling 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.

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Heat 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.

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Types of Heat Transfer
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Spontaneous 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. Proper
• containers are required.

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Classification of Fires

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

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Class A Fire

• Ordinary materials
• Wood, paper, garbage
• Class A fires are extinguished by the quenching
  and cooling effects of water.

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Class B Fire

• Flammable or combustible gases and liquids.
• Gasoline, kerosene, propane, grease, paint
  thinner, paint, oil.
• Water will spread the fire. Use dry chemicals,
  CO2, or foam.

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Class C Fires

• Energized electrical equipment.
• Appliances, power tools, switches.
• Do not use foam or water (they conduct
  electricity).
• Use dry chemicals or CO2.

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Class 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.

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Fire Prevention
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Fire Prevention

• Practise Good Housekeeping
• Keep work area free of clutter
• Clean flammable dust regularly (sawdust)
• Wipe up spills of flammable liquids
• Keep fire exits and exit routes clear
• Never use alcohol or gasoline as a cleaning agent
• Store flammable waste in proper containers
• Store flammable liquids properly
• Extinguish cigarettes in proper containers
• Obey all No Smoking signs

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Fire Prevention

• Avoid Electrical Hazards
• Don't overload circuits
• Discard frayed or worn cords
• Check for problems with electrical equipment
• Overheating
• Faulty switches
• Exposed wires
• Never use a tool or extension cord if the
  grounding plug has been removed.

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Fire Prevention

• Be careful handling flammable, combustible, and
  explosive materials
• Flammable materials that catch fire and burn
  easily and give off intense heat
• Liquids gasoline, acetone
• Solids phosphorous, magnesium, sodium
• Gases propane, acetylene, hydrogen

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Fire Prevention

• Combustible materials that will burn under
  ordinary circumstances because of an outside
  source
• paper,
• wood,
• cloth

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Fire Prevention

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

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Fire 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

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Fire 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.

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Fire Prevention

• Be aware of possible ignition sources
• Flame
• Cigarettes
• Static electricity
• Sparks
• Welding
• Furnaces
• Hot ash
• Heating elements
• Electrical switches

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Responding 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

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Escape and Muster Plans
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Industrial 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.

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Industrial 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.

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Fire Detection

• Fire detection devices include
• Human observers
• Automatic sprinklers
• Smoke, flame, heat, CO2, and CO detectors

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Fire 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

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Fire 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