1. Portable Fire Extinguishers (Fire Fighter I)
CHAPTER 8
Portable Fire Extinguishers
(Fire Fighter I) 1

2. Fire Fighter I Objectives
State the primary purposes of fire extinguishers.
Define Class A fires.
Define Class B fires.
Define Class C fires.
Define Class D fires.
Define Class K fires. 2

3. Fire Fighter I Objectives
Explain the classification and rating system for fire extinguishers.
Describe the types of agents used in fire extinguishers.
Describe the types of operating systems in fire extinguishers. 3

4. Fire Fighter I Objectives
Describe the basic steps of fire extinguisher operation.
Explain the basic steps of inspecting, maintaining, recharging, and hydrostatic testing of fire extinguishers.
Select the proper class of fire extinguisher. 4

5. Introduction
Portable fire extinguishers are required in a variety of occupancies.
Vary in size and type of agent used
Designed for different purposes 5

6. Introduction 6 Courtesy of Amerex Corporation

7. Purposes of Fire Extinguishers
Extinguish incipient fires
Control fires where traditional methods are not recommended
Provide discharge patterns for specific fuels 7

8. Use of Portable Fire Extinguishers
Most fire departments carry at least one; many carry two or more.
Advantage: portability
Disadvantage: “one-shot” devices 8

9. Special Extinguishing Agents
As a fire fighter, you must know:
Which fires require special agents
What type should be used
How to operate the different types 9

10. Classes of Fires Essential to match extinguisher and fire
Some agents are more efficient on certain fires.
Some agents will not control certain fires.
Some agents are dangerous when applied to certain fires. 10

11. Class A Fires Involve ordinary combustibles and natural vegetation
Water is the most common extinguishing agent. 11

12. Class B Fires
Involve flammable or combustible liquids and flammable gases
Several different types of extinguishing agents are approved. 12

13. Class C Fires Involve energized electrical equipment
Can generate tremendous heat that ignites nearby Class A or B materials
Agents that will not conduct electricity must be used.
Courtesy of Tyco Fire and Building Products 13

14. Class D Fires Involve combustible metals
Special techniques and agents are required.
Normal agents can react violently.
© Andrew Lambert Photography/Photo Researchers, Inc. 14

15. Class K Fires Involve combustible cooking oils and fats
Some restaurants still use Class B extinguishers.
© Scott Leman/ShutterStock, Inc. 15

16. Classification of Fire Extinguishers
Based on characteristics and capabilities
Underwriters Laboratories, Inc., develops standards for ratings and classification.
Rated for safety and effectiveness 16

17. Classification of Fire Extinguishers
System uses letters and numbers.
Letters indicate the class of fire for which the extinguisher can be used.
Numbers indicate its effectiveness. 17

18. Classification of Fire Extinguishers
Standard test fires are used to rate the effectiveness of fire extinguishers
May involve different agents, amounts, application rates, and application amounts 18

19. Labeling of Fire Extinguishers
Traditional lettering system has been used for many years. 19

20. Labeling of Fire Extinguishers
Pictograph system has recently been developed. 20

21. Fire Extinguisher Placement
NFPA Standard 10 lists recommendations for placing and mounting portable fire extinguishers.
Occupancy regulations specify area protected, travel distance, and types of extinguishers provided. 21

22. Fire Extinguisher Placement
Two factors to consider to determine the type of extinguisher:
Class of fire likely to occur
Potential magnitude of an incipient fire 22

23. Fire Extinguisher Placement
Extinguishers should be mounted so they are readily visible and easily accessed. 23

24. Classifying Area Hazards
Areas are divided into risk classifications according to the amount and type of combustibles that are present.
The recommended classifications are guidelines based on typical situations. 24

25. Light or Low Hazard
Areas where most materials are noncombustible or arranged so a fire is not likely to spread
Contain limited amounts of Class A and Class B combustibles 25

26. Ordinary or Moderate Hazard
Contain more Class A and Class B materials than light hazard locations
Include warehouses that contain Class I and Class II commodities 26

27. Extra or High Hazard Contain more Class A and Class B materials
Include areas used for manufacturing or handling flammable liquids; warehouses containing products that are not Class I or Class II commodities 27

28. Determining the Appropriate Placement of Fire Extinguisher
Consider the types and quantities of fuels found in the area.
Some areas may need extinguishers with more than one rating or more than one type of fire extinguisher. 28

29. Methods of Fire Extinguishment
Fires require fuel, heat, and oxygen.
Rapid oxidation
Occurs when a fuel is combined with oxygen
Combustion
Occurs when fuel is heated to its kindling temperature 29

30. Methods of Fire Extinguishment
Extinguishers stop burning by:
Cooling the fuel
Cutting off the supply of oxygen
Interrupting the chain of reactions 30

31. Types of Extinguishing Agents
Substance contained in portable fire extinguisher that puts out a fire
Various chemicals are used.
Best agent depends on several factors.
Types of materials involved
Anticipated size of the fire 31

32. Types of Extinguishing Agents
Water
Dry chemicals
Carbon dioxide
Foam
Wet chemicals
Halogenated agents
Dry powder 32

33. Water Efficient, plentiful, and inexpensive Effective on Class A fires
Less effective on other classes
Disadvantage: Freezes at 32ºF (0ºC)
Load-stream extinguishers, wetting agents, or water mist can be used. 33

34. Dry Chemical Stream of finely ground particles
Different types of compounds are used.
Extinguish in two ways:
Interrupts chemical chain reaction
Absorbs large quantities of heat 34

35. Dry Chemical Several advantages over water extinguishers
Ordinary: Suitable for Class B and C fires
Multipurpose: Rated for Class A, B, and C fires 35

36. Dry Chemical Additives prevent packing and caking.
Disadvantage: Chemicals are corrosive.
Primary compounds:
Sodium bicarbonate
Potassium bicarbonate
Urea-based potassium carbonate
Potassium chloride
Ammonium phosphate 36

37. Carbon Dioxide Forms a dense cloud displacing air surrounding the fuel
Interrupts combustion by:
Reducing the oxygen
Disrupting liquid fuel’s ability to vaporize 37

38. Carbon Dioxide Stored under pressure as a liquid
Rated for Class B and C fires only
Does not conduct electricity; is not corrosive; does not leave any residue 38

39. Carbon Dioxide Limitations include: Weight Range Weather
Confined spaces
Suitability 39

40. Foam Water-based foam concentrate solution Use on Class A or B fires.
Additives depend on compatibility with fuels. 40

41. Foam Some foams are approved for polar solvents.
Not suitable for Class C fires
Cannot be stored or used at freezing temperatures
© craftvision/iStockphoto.com 41

42. Wet Chemical Only agent to meet Class K fire rating
Saponification: Converts fatty acids in cooking oils or fats to soap or foam
Creates thick blanket to smother the fire
Very effective and easy to clean up 42

43. Halogenated Agents Produced from family of liquefied gases
“Clean agents”
Twice as effective as carbon dioxide
Two categories
Halons: Use limited by Montreal Protocol
Halocarbons: Replaced halons 43

44. Halogenated Agents
Stored as liquids and discharged under high pressure
Vapor mist disrupts chain reaction.
Dissipate in windy conditions
Displace oxygen in confined spaces
Halon 1211 should rarely be used. 44

45. Dry Powder Used on combustible metal fires (Class D)
Stored in granular or powdered form
Forms solid crust over burning metal
Commonly used agents are sodium chloride or graphite powder
Avoid splatter and water 45

46. Fire Extinguisher Design
Use pressure to expel contents.
Many extinguishers require pressurized gas to expel the agent.
Some agents are self-expelling.
Hand-operated pumps expel water or water with additives. 46

47. Portable Fire Extinguisher Components
Most hand-held extinguishers have six basic parts:
Cylinder or container
Carrying handle
Nozzle or horn
Trigger
Locking mechanism
Pressure indicator
Courtesy of Amerex Corporation 47

48. Portable Fire Extinguisher Components
Cylinder or container
Body of the extinguisher
Holds the extinguishing agent
Nitrogen, compressed air, or carbon dioxide used to pressurize the cylinder 48

49. Portable Fire Extinguisher Components
Handle
Used to carry an extinguisher and to hold it during use
Extinguishers weighing more than 3 lb (1.35 kg) must have handles.
Usually located below the trigger mechanism 49

50. Portable Fire Extinguisher Components
Nozzle or horn
Expels agent
Attached directly to valve assembly or at the end of a short hose
Foam extinguishers have a special aspirating nozzle. 50

51. Portable Fire Extinguisher Components
Trigger
Mechanism that is squeezed or depressed to discharge extinguishing agent
Usually a lever located above the handle
Cartridge/cylinder models usually have a two-step operating sequence. 51

52. Portable Fire Extinguisher Components
Locking mechanism
Prevents unintentional discharge
Simplest form is a stiff pin
Tamper seal secures the pin
Discourages people from tinkering with extinguisher 52

53. Portable Fire Extinguisher Components
Pressure indicator
Shows whether a stored-pressure extinguisher has sufficient pressure to operate
Most extinguishers use a needle gauge.
Extinguishers pressurized by a cartridge lack a pressure gauge. 53

54. Wheeled Fire Extinguishers
Large units mounted on wheeled carriages
Typically contain 150 to 350 lb ( kg) of agent
Long delivery hoses allow operators to attack fire from multiple sides.
Installed in special hazard areas 54

55. Fire Extinguisher Characteristics
Portable extinguishers vary according to:
Extinguishing agent
Capacity
Effective range
Time it takes to completely discharge agent
Extinguishers also have different mechanical designs. 55

56. Water Extinguishers
Used to cool burning fuel below its ignition temperature
Intended primarily for Class A fires 56

57. Water Extinguishers Stored-pressure water type
Used for incipient Class A fires
Contents can freeze
Can be recharged at any location that provides water and compressed air 57

58. Water Extinguishers Loaded-stream water type
Discharge solution of water containing an alkali metal salt
Usable to −40ºF(−40ºC)
Most common model is 2.5-gallon (9.5-L) unit. 58

59. Water Extinguishers Wetting agent, Class A foam water-type
Solution reduces surface tension.
Allows water to penetrate Class A
Do not expose to temperatures below 40ºF (−40ºC). 59

60. Water Extinguishers Pump-tank water-type
Range from 1-A rated, 1.5-gallon (5.7-L) units, to 4- A rated, 5-gallon (19-L) units
Nonpressurized storage
Expelled via hand-operated piston pump
Sits upright on the ground
Can be used with antifreeze solution 60

61. Water Extinguishers Backpack water-type
Used primarily for brush and grass fires
Wide mouth opening with filter allows easy refill.
Filter keeps contaminates from entering the tank 61

62. Dry Chemical Extinguishers
Contain variety of agents in granular form
Ordinary models extinguish Class A and B fires.
Multipurpose models extinguish Class A, B, and C fires.
All can be used on Class C fires, but residue damages electronics. 62

63. Dry Chemical Extinguishers
Range of discharge is from 5' to 30‘ ( m), depending on size.
Trigger allows intermittent discharge.
Extinguishers do not retain internal pressure for extended periods. 63

64. Dry Chemical Extinguishers
Ordinary
Hand-held models or wheeled units
Multipurpose
Aluminum phosphate agent
Hand-held models or large wheeled units
Should never be used for Class K fires 64

65. Carbon Dioxide Extinguishers
Rated for Class B and C fires
Envelopes fuel in a cloud of inert gas
Also cools the burning material
Colorless, odorless, nonconductive, and inert gas 65

66. Carbon Dioxide Extinguishers
An expelling and extinguishing agent
Have relatively short discharge ranges
Not recommended outdoors or near strong air currents 66

67. Carbon Dioxide Extinguishers
Trigger mechanism allows intermittent operation.
Extinguisher will have to be recharged after use.
Extinguisher is weighed to determine how much agent is left in the storage cylinder. 67

68. Class B Foam Extinguishers
Aspirating nozzle discharges solution of water and aqueous film-forming foam and film- forming fluoroprotein agent.
Foam blanket floats over surface of liquid.
Effective for Class A and B fires but not suitable for Class C or K fires
Not effective at freezing temperatures 68

69. Wet Chemical Extinguishers
Used to protect Class K installations
Commercial facilities use fixed, automatic systems.
Portable extinguishers available.
No numerical ratings 69

70. Halogenated-Agent Extinguishers
Include both halon and halocarbon agents
Available in hand-held models rated for Class B and C fires
Agent discharged as a streaming liquid
Nonconductive and leave no residue 70

71. Dry Powder Extinguishing Agents
For Class D fires involving combustible metals
Agents and techniques vary.
Each agent listed for use on specific combustible metal fires 71

72. Dry Powder Extinguishing Agents
Dry powder fire extinguishers
Adjustable nozzles allow operator to vary the flow of agent
Bulk dry powder agents
Applied manually using a shovel or scoop 72

73. Use of Fire Extinguishers
Six basic steps for extinguishing fires:
Locate the fire.
Select the proper extinguisher.
Transport the extinguisher to the fire.
Activate the extinguisher to release the agent.
Apply the extinguishing agent.
Ensure personal safety. 73

74. Locating a Fire Extinguisher
Know the types and locations of extinguisher on apparatus.
Know where extinguishers are located in and around the fire station.
Have at least one extinguisher in your home and another in your personal vehicle. 74

75. Selecting the Proper Extinguisher
Requires an understanding of the classification and rating system
Fire fighters must quickly determine whether a fire can be controlled by an extinguisher.
Fire fighters should also determine the appropriate type of extinguisher to place in a given area. 75

76. Transporting a Fire Extinguisher
Best method depends on size, weight, and design of extinguisher.
Carry fixed nozzle units in stronger hand.
Use weaker hand for units with a hose between trigger and nozzle. 76

77. Basic Steps of Fire Extinguisher Operation
PASS acronym:
Pull the safety pin.
Aim the nozzle at the base of the flames.
Squeeze the trigger to discharge agent.
Sweep the nozzle across the base of the flames. 77

78. Ensure Your Personal Safety
Approach fire with an exit behind you.
Have a planned escape route.
Never let fire get between you and exit.
Never turn your back on the fire.
Watch fire for rekindle.
Wear appropriate PPE and SCBA. 78

79. Care of Fire Extinguishers
Extinguishers must be regularly inspected and properly maintained.
Records keep inspections and maintenance on schedule.
Proper training required.
Follow manufacturer’s recommendations. 79

80. Inspection Check extinguishers on apparatus once per month.
Check tamper seals.
Weigh or “heft” to determine fullness.
Examine for obvious physical damage, corrosion, or leaks. 80

81. Inspection Check pressure gauge. Confirm proper identification.
Check hose and nozzle for damage or obstructions.
Check the hydrostatic test date. 81

82. Maintenance Includes internal inspections and repairs
Must be performed periodically
Only qualified personnel can perform maintenance. 82

83. Common Indicators of Need for Maintenance
Pressure gauge reads outside normal range
Inspection tag is out-of-date
Broken tamper seal
Any indication that unit is not full
Obstructed hose or nozzle assembly
Physical damage, corrosion, or rust
Leakage around the discharge valve or nozzle assembly 83

84. Recharging Required after every use
Replace only when properly recharged.
Extinguishing agent refilled
Expulsion agent recharged
Tamper seal installed after recharging 84

85. Hydrostatic Testing
Measures extinguisher’s ability to withstand internal pressure
Special test facility required
Above-normal pressure is applied to water- filled cylinder 85

86. Hydrostatic Testing
Must indicate most recent test on the outside of the extinguisher
All out-of-date extinguishers must be tested at an appropriate facility. 86

87. Summary Fire extinguishers put out hundreds of fires every day.
Fire fighters use fire extinguishers to control small fires.
Portable fire extinguishers are used to:
Extinguish incipient-stage fires
Control fires where traditional methods are not recommended 87

88. Summary Fire extinguishers are one time use only.
The five classes of fires are: Class A, B, C, D, and K.
Portable fire extinguishers are classified and rated based on their characteristics and capabilities.
Fire extinguisher classification uses both letters and numbers. 88

89. Summary
Traditional lettering system for fire extinguishers are Class A, Class B, Class C, Class D, and Class K.
The pictograph system uses symbols for classifying fire extinguishers.
NFPA 10 lists requirements for placing and mounting portable fire extinguishers.
There are three risk classifications. 89

90. Summary
Extinguishers stop fire by cooling fuel, cutting off supply, or a combination.
Portable fire extinguishers use seven basic types of extinguishing agents.
Portable fire extinguishers vary according to their agent, capacity, range, and the time it takes to discharge. 90

91. Summary
There are six basic steps in extinguishing a fire with a portable fire extinguisher.
There are four steps to activating a fire extinguisher.
Use a fire extinguisher with an exit and the wind at your back.
Inspect and maintain fire extinguishers. 91

92. Summary
Fire fighters inspecting extinguishers should follow specific guidelines.
There are common indications that an extinguisher needs maintenance.
A fire extinguisher must be recharged after every use.
Most fire extinguishers are pressurized vessels. 92