Essentials of Fire Fighting, 5th Edition Chapter 6

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• Essentials of Fire Fighting,
• 5th Edition

Chapter 6 Portable Fire Extinguishers Firefight
er I
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Chapter 6 Lesson Goal

• After completing this lesson, the student shall
  be able to operate portable fire extinguishers
  effectively and safely following the policies and
  procedures set forth by the authority having
  jurisdiction.

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Specific Objectives

• 1. Describe methods by which agents extinguish
  fire.
• 2. List mechanisms by which portable
  extinguishers expel their contents.
• 3. Distinguish among classifications of fires
  and the most common agents used to extinguish
  them.

(Continued)
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Specific Objectives

• 4. Describe types of extinguishers and their
  common uses.
• 5. Discuss extinguishers and agents for metal
  fires.
• 6. Explain the portable extinguisher rating
  system.

(Continued)
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Specific Objectives

• 7. Describe factors to consider in selecting the
  proper fire extinguisher.
• 8. Describe items to check for immediately
  before using a portable fire extinguisher.
• 9. Describe the PASS method of application.

(Continued)
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Specific Objectives

• 10. Summarize procedures that should be part of
  every fire extinguisher inspection.
• 11. Discuss damaged portable fire extinguishers
  and obsolete portable fire extinguishers.

(Continued)
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Specific Objectives

• 12. Operate a stored pressure water
  extinguisher.
• 13. Operate a dry chemical (ABC) extinguisher.
  (Skill Sheet 6-I-2)
• 14. Operate a carbon dioxide (CO2) extinguisher.
  (Skill Sheet 6-I-3)

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Fire Extinguishment Methods

• Smothering
• Cooling
• Chain breaking
• Saponification

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Portable Extinguisher Expulsion Mechanisms

• Manual pump
• Stored pressure
• Pressure cartridge

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Fire Classifications

• Class A fires Involve ordinary combustibles
• Easily extinguished with water, water-based
  agents (foam), dry chemicals
• Water most common agent used by fire service

(Continued)
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Fire Classifications

• Class B fires Involve flammable/combustible
  liquids, gases, greases
• Special fire hazards should not be extinguished
  until fuel gas shut off
• Special-hazard fires get larger as fuel volume
  increases
• Extinguishing agents include carbon dioxide, dry
  chemical, Class B foam

(Continued)
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Fire Classifications

• Class C fires Involve Class A or B fires
  created by electrical energy
• Do not use water, water-based agents until
  electrical energy eliminated
• Recommended method is to turn off ordisconnect
  electrical power before using appropriate
  extinguisher

(Continued)
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Fire Classifications

• Class D fires Involve combustible metals,
  alloys
• Can be identified by bright white emissions from
  combustion process
• Class D, dry powder extinguishers work best

(Continued)
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Fire Classifications

• Class K fires Involve combustible cooking oils
• Examples are vegetable fats that burn at
  extremely high temperatures
• Most fuels found in commercial kitchens can also
  be found in private homes
• Wet chemicals used in extinguishing systems

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Pump-Type Water Extinguishers

• Intended for use on small Class A fires only
• All operate in similar manner
• Equipped with single- or double-acting pump

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Stored-Pressure Water Extinguishers

• Air-pressurized water extinguishers or
  pressurized water extinguishers
• Useful for all types of small Class A fires

(Continued)
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Stored-Pressure Water Extinguishers

• Often used for extinguishing hot spots
• Operation
• Water stored in tank w/air or nitrogen
• Gauge shows pressurization
• Pressure forces water up tube, out hose
• Class A foam concentrate sometimes added

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Water-Mist Stored-Pressure Extinguishers

• Use deionized water as agent, nozzles produce
  fine spray instead of stream
• Deionized water makes safe for use on energized
  electrical equipment
• Fine spray enhances cooling/soaking
  characteristics, reduces scattering of burning
  material

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Wet Chemical Stored-Pressure Extinguishers

• Specifically designed to control/extinguish Class
  K fires in deep fryers
• Contain special potassium-based low-pH agent to
  cool/suppress fires in unsaturated cooking oils

Courtesy of Ansul Corp.
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Aqueous Film Forming Foam (AFFF) Extinguishers

• Suitable for Class A, Class B fires
• Fires/vapors from small liquid fuel spills
• Different from stored-pressure water
  extinguishers
• Tank contains specified amount of AFFF
  concentrate mixed with water
• Air-aspirating nozzle aerates solution

(Continued)
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Aqueous Film Forming Foam (AFFF) Extinguishers

• Water/AFFF solution expelled by compressed air or
  nitrogen
• To prevent disturbance of foam blanket, do not
  apply directly onto fuel allow to rain onto
  surface/deflect off object

(Continued)
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Aqueous Film Forming Foam (AFFF) Extinguishers

• When AFFF/water mixed, finished foam floats on
  fuels lighter than water
• Vapor seal created by film of water extinguishes
  flame, prevents reignition

(Continued)
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Aqueous Film Forming Foam (AFFF) Extinguishers

• Foam has good wetting, penetrating properties on
  Class A fuels ineffective on polar solvents
• Not suitable for fires in Class C, D fuels
• Most effective on static pools of flammable
  liquids

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Clean Agent Extinguishers

• Designed as replacement for Halon 1211, use
  clean agents that discharge as rapidly
  evaporating liquids that leaves no residue
• Cool/smother fires in Class A, B fuels
• Nonconductive so can be used on Class C
• Approved by U.S. EPA

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Carbon Dioxide (CO2) Extinguishers

• Found as both handheld/wheeled units
• Most effective in Class B, C fires
• Have limited reach gas can be dispersed by wind

Courtesy of Badger Fire Protection
(Continued)
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Carbon Dioxide (CO2) Extinguishers

• Carbon dioxide stored under its own pressure as
  liquefied gas ready for release at any time
• Wheeled units similar to handheld except wheeled
  are considerably larger

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Dry Chemical Extinguishers

• For Class A-B-C fires and/or Class B-C fires dry
  powder used on Class D only
• Commonly used today

(Continued)
Courtesy of Ansul Corp.
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Dry Chemical Extinguishers

• Two basic types
• Regular BC-rated
• Multipurpose and ABC-rated
• Commonly used dry chemicals
• Handheld units
• Wheeled units

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Controlling/Extinguishing Metal Fires

• Special extinguishing agents, application
  techniques developed to control/extinguish metal
  fires
• No single agent controls/extinguishes fires in
  all combustible metals

(Continued)
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Controlling/Extinguishing Metal Fires

• Some powdered agents applied with portable
  extinguishers, others with shovel or scoop
• Appropriate application technique described in
  manufacturers technical sales literature

(Continued)
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Controlling/Extinguishing Metal Fires

• Portable extinguishers for Class D come in both
  handheld, wheeled units
• Regardless of applicator, powder must be applied
  in sufficient depth to completely cover burning
  area to create smothering blanket

(Continued)
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Controlling/Extinguishing Metal Fires

• Operation
• If small amount of burning metal on combustible
  surface, fire should be covered with powder
• 1 to 2 inch (25 to 50 mm) layer spread nearby,
  burning metal shoveled onto layer
• After extinguishment, material left undisturbed
  until cooled

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Portable Extinguisher Rating System

• Portable extinguishers classified according to
  types of fire they extinguish
• Class A, B also rated according to performance
  capability
• System based on tests by UL, ULC

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Classifications

• Class A From 1-A through 40-A
• Class B From 1-B through 640-B
• Class C No tests
• Class D Test fires vary
• Class K Recognized by UL, ULC since 1996

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Multiple Markings

• Extinguishers for more than one class of fire
  identified by combinations of A, B, and/or C or
  symbols for each class
• Most common are A-B-C, A-B, B-C
• All must be labeled appropriately
• Unlisted units should not be used
• Ratings for each class are independent

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Identification Two Ways

• Geometric shapes of specific colors with class
  letter shown within shape
• NFPA 10 recommended Uses pictographs to make
  selection easier shows types of fires on which
  extinguishers should not be used

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Extinguisher Selection Factors

• Classification of burning fuel
• Rating of extinguisher
• Hazards to be protected
• Size/intensity of fire

(Continued)
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Extinguisher Selection Factors

• Atmospheric conditions
• Availability of trained personnel
• Ease of handling extinguisher
• Life hazard/operational concerns

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Extinguisher Selection Considerations

• Select those that minimize risk to life/property
  and are effective in extinguishing the fire type
• Dry chemical extinguishers should not be selected
  for use in areas where highly sensitive computer
  equipment is located

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Extinguisher Check

• Immediately before use
• External condition
• Hose/nozzle
• Weight
• Pressure gauge
• After selecting size/type for situation, approach
  fire from windward side

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Fire Extinguisher Operation

• All modern extinguishers operate in similar
  manner
• Pick up extinguisher by handles, carry to point
  of application

(Continued)
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Fire Extinguisher Operation

• Once in position, use PASS method
• P Pull the pin
• A Aim the nozzle
• S Squeeze handles together
• S Sweep nozzle back and forth

(Continued)
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Fire Extinguisher Operation

• Be sure agent reaches fire
• Apply agent from point where stream reaches but
  does not disturb fuel
• After fire knocked down, move closer to achieve
  final extinguishment

(Continued)
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Fire Extinguisher Operation

• If extinguishment not achieved after entire
  extinguisher discharged, withdraw/reassess
• If fire is in solid fuel reduced to smoldering
  phase, may be overhauled using appropriate tool

(Continued)
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Fire Extinguisher Operation

• If fire in liquid fuel, it may be necessary to
  apply foam through hoseline or simultaneously
  attack with more than one extinguisher
• If more than one extinguisher used
  simultaneously, work in unison and maintain
  constant awareness

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Fire Extinguisher Inspections

• NFPA 10 and most fire codes require portable
  extinguishers inspected at least once/year
• Verify that extinguishers
• Are in designated locations
• Not tampered with or activated
• No obvious damage/other condition

(Continued)
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Fire Extinguisher Inspections

• Servicing responsibility of property
  owner/building occupant
• Firefighters should include inspections in
  building inspection program

(Continued)
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Fire Extinguisher Inspections

• Three factors determine value
• Serviceability
• Accessibility
• Simplicity of operation
• NFPA 10 describes procedures for hydrostatic
  testing of cylinders

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Parts of Fire Extinguisher Inspections

• Ensure extinguisher in proper location/accessible
• Inspect discharge nozzle
• Inspect extinguisher shell
• Check for legible operating instructions on
  nameplate

INACCESSIBLE
(Continued)
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Parts of Fire Extinguisher Inspections

• Check locking pin, tamper seal
• Determine whether full of agent, fully
  pressurized
• Check for date of previous inspection
• Examine condition of hose/fittings
• If any items deficient, remove from service

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Damaged Fire Extinguishers

• Can fail at any time could result in serious
  injury
• Leaking, corroded, otherwise damaged
  shells/cylinders should be discarded or returned
  to manufacturer for repair

(Continued)
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Damaged Fire Extinguishers

• Only slight damage/corrosion and uncertain
  whether safe Should be hydrostatically tested
• If allowed by SOP, leaking hoses, gaskets,
  nozzles, and loose labels can be replaced by
  firefighters

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Obsolete Portable Fire Extinguishers

• In 1969
• American manufacturers stopped making
  inverting-type extinguishers
• Manufacturing of extinguishers made of copper or
  brass with cylinders soft soldered or riveted
  together discontinued

(Continued)
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Obsolete Portable Fire Extinguishers

• Extinguishers using carbon tetrachloride and
  chlorobromomethane prohibited in workplace
• If obsolete extinguishers are discovered and
  occupant requests, firefighters should follow SOP
  to dispose of them

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Halon Fire Extinguishers

• Included in Montreal Protocol
• U.S. stopped producing halogens at end of 1993
• Units may still be in service

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Summary

• In many cases, fire extinguishers can control or
  extinguish small fires in less time than it takes
  to deploy a hoseline.

(Continued)
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Summary

• Even though portable fire extinguishers may be
  found in many of the homes, apartments, and
  businesses that must be entered to extinguish
  fire, firefighters should only rely on those
  carried on the fire apparatus.

(Continued)
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Summary

• To use fire extinguishers safely and effectively,
  firefighters must know capabilities and
  limitations of the extinguisher and their own
  capabilities and limitations as well as the
  proper techniques for their application.

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Review Questions

• 1. What are the five classes of fire and what do
  they involve?
• 2. What fires are aqueous film forming foam
  (AFFF) extinguishers most effective on?
• 3. How do carbon dioxide (CO2) portable
  extinguishers work?

(Continued)
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Review Questions

• 4. What are the three most common combinations
  for extinguishers with multiple markings?
• 5. List three factors that affect the selection
  of the proper portable fire extinguisher.

(Continued)
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Review Questions

• 6. What should be checked immediately before
  using a portable extinguisher?
• 7. What is the PASS method of application?
• 8. What procedures should be part of every fire
  extinguisher inspection?