0. Essentials of Fire Fighting, 5th Edition
Chapter 6 — Portable Fire Extinguishers
Firefighter I

1. 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.
Firefighter I

2. 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)
Firefighter I

3. 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)
Firefighter I

4. 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)
Firefighter I

5. 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)
Firefighter I

6. 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)
Firefighter I

7. Fire Extinguishment Methods
Smothering
Cooling
Chain breaking
Saponification
Firefighter I

8. DISCUSSION QUESTION
Has anyone in the class ever used a portable fire extinguisher to extinguish a fire?
Firefighter I

9. Portable Extinguisher Expulsion Mechanisms
Manual pump
Stored pressure
Pressure cartridge
Firefighter I

10. 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)
Firefighter I

11. 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)
Firefighter I

12. 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 or disconnect electrical power before using appropriate extinguisher
(Continued)
Firefighter I

13. 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)
Firefighter I

14. DISCUSSION QUESTION
Why should water-based agents not be used on Class D fires?
Firefighter I

15. 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
Firefighter I

16. 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
Firefighter I

17. Stored-Pressure Water Extinguishers
Air-pressurized water extinguishers or pressurized water extinguishers
Useful for all types of small Class A fires
(Continued)
Firefighter I

18. 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
Firefighter I

19. 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
Firefighter I

20. Wet Chemical Stored-Pressure Extinguishers
Specifically designed to control/extinguish Class K fires in deep fryers
Contain special potassium-based alkaline agent to cool/suppress fires in unsaturated cooking oils
Courtesy of Ansul Corp.
Firefighter I

21. 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)
Firefighter I

22. 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)
Firefighter I

23. 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)
Firefighter I

24. 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
Firefighter I

25. 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
Firefighter I

26. 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
(Continued)
Courtesy of Ansul Corp.
Firefighter I

27. 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
Courtesy of Badger Fire Protection.
Firefighter I

28. DISCUSSION QUESTION
What is the danger of touching the horn on a carbon dioxide extinguisher shortly after it has been used?
Firefighter I

29. 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.
Firefighter I

30. Dry Chemical Extinguishers
Two basic types
Regular B:C-rated
Multipurpose and A:B:C-rated
Commonly used dry chemicals
Handheld units
Wheeled units
Courtesy of Ansul Corp.
Firefighter I

31. DISCUSSION QUESTION
What happens when water is applied to a combustible metal fire?
Firefighter I

32. 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)
Firefighter I

33. Controlling/Extinguishing Metal Fires
Some powdered agents applied with portable extinguishers, others with shovel or scoop
Appropriate application technique described in manufacturer’s technical sales literature
(Continued)
Firefighter I

34. Controlling/Extinguishing Metal Fires
Portable extinguishers for Class D come in both handheld, wheeled units
Courtesy of Amerex Corp.
(Continued)
Firefighter I

35. Controlling/Extinguishing Metal Fires
Regardless of applicator, powder must be applied in sufficient depth to completely cover burning area to create smothering blanket
(Continued)
Firefighter I

36. Controlling/Extinguishing Metal Fires
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
Firefighter I

37. 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
Firefighter I

38. 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
Firefighter I

39. 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
Firefighter I

40. 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
Firefighter I

41. Extinguisher Selection Factors
Classification of burning fuel
Rating of extinguisher
Hazards to be protected
Size/intensity of fire
(Continued)
Firefighter I

42. Extinguisher Selection Factors
Atmospheric conditions
Availability of trained personnel
Ease of handling extinguisher
Life hazard/operational concerns
Firefighter I

43. 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
Firefighter I

44. Extinguisher Check Immediately before use
External condition
Hose/nozzle
Weight
Pressure gauge
After selecting size/type for situation, approach fire from windward side
Firefighter I

45. DISCUSSION QUESTION Why should you always have an escape route?
Firefighter I

46. Fire Extinguisher Operation
All modern extinguishers operate in similar manner
Pick up extinguisher by handles, carry to point of application
(Continued)
Firefighter I

47. 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)
Firefighter I

48. 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 for final extinguishment
(Continued)
Firefighter I

49. 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)
Firefighter I

50. 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
Firefighter I

51. 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)
Firefighter I

52. Fire Extinguisher Inspections
Servicing responsibility of property owner/building occupant
Firefighters should include inspections in building inspection program
(Continued)
Firefighter I

53. Fire Extinguisher Inspections
Three factors determine value
Serviceability
Accessibility
Simplicity of operation
NFPA® 10 describes procedures for hydrostatic testing of cylinders
Firefighter I

54. 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)
Firefighter I

55. 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
Firefighter I

56. 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)
Firefighter I

57. DISCUSSION QUESTION
How should a defective fire extinguisher be repaired?
Firefighter I

58. 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
Firefighter I

59. Obsolete Portable Fire Extinguishers
American manufacturers stopped making inverting-type extinguishers
Manufacturing of extinguishers made of copper or brass with cylinders soft soldered or riveted together discontinued
(Continued)
Firefighter I

60. 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
Firefighter I

61. Halon Fire Extinguishers
Included in Montreal Protocol
U.S. stopped producing halogens at end of 1993
Units may still be in service
Firefighter I

62. Summary
In many cases, fire extinguishers can control or extinguish small fires in less time than it takes to deploy a hoseline.
(Continued)
Firefighter I

63. 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)
Firefighter I

64. 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.
Firefighter I

65. 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)
Firefighter I

66. 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)
Firefighter I

67. 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?
Firefighter I