- Portable fire extinguishers are classified based on the type of fuel that is burning and appropriate extinguishing agents are chosen accordingly. Common classifications include Class A for ordinary combustibles, Class B for flammable liquids, Class C for energized electrical fires, Class D for combustible metals, and Class K for cooking oils. - Fire extinguishers are also rated based on their capabilities. Ratings identify the types of fires they can be used on as well as their relative sizes. Instruction and practice is needed to properly select, inspect, maintain, and operate portable fire extinguishers for controlling small fires.

1. Essentials of Fire Fighting
6th Edition
Firefighter I
Chapter 7 — Portable Fire
Extinguishers

2. Explain portable fire extinguisher
classifications.
Learning Objective 1
7–2

3. Portable fire extinguishers are chosen
based on the type of fuel burning.
7–3

4. Fuel
• Textiles
• Paper
• Plastics
• Rubber
• Wood
Extinguished with:
•Water
•Water-based agents
(Class A foam)
•Dry Chemicals
Class A fires involve
ordinary combustibles.
7–4

5. Fuel
• Alcohol
• Gasoline
• Lubricating Oils
• Liquefied petroleum
gas (LPG)
Extinguished with:
•Carbon Dioxide
•Dry Chemicals
•Class B Foam
7–5
Class B fires involve flammable,
combustible liquids and gases.

6. Class C fire involves energized
electrical equipment.
7–6
Treat as Class A
or B once power
is off

7. Class D fires involve combustible
metals and alloys.
7–7

8. CAUTION!
The use of water or water-based agents
on Class D fires will cause the fire to
react violently, emit bits of molten metal,
and possibly injure firefighters close by.
7–8

9. Use dry powder, not dry chemical,
extinguishers on Class D fires.
7–9

10. CAUTION!
Do not use a dry chemical extinguisher
on Class D fire. The dry chemical often
reacts violently with burning metals.
7–10

11. Class K fires involve combustible
cooking oils.
7–11
• Vegetable or animal
fats
• Burn at extreme
temperatures
• Found at commercial,
institutional,
industrial, home
Controlled by
wet chemical
systems,
portable
extinguishers

12. REVIEW QUESTION
How are the classifications for
portable fire extinguishers divided?
7–12

13. Describe types of portable fire
extinguishers.
Learning Objective 2
7–13

14. Fire extinguishers are organized by
type of extinguishing agent and the
method used to expel their contents.
7–14
(Cont.)

15. Fire extinguishes are organized by
type of extinguishing agent and the
method used to expel their contents.
7–15

16. 7–16
Use pump-type water extinguishers on
small Class A fires, ground cover
fires.

17. Use stored-pressure water
extinguishers on small Class A
fires.
7–17

18. Use water-mist stored-pressure
extinguishers on Class C fires.
7–18
Deionized water
Normal water
Water-mist stored-pressure
Stored-pressure water

19. Use wet chemical stored-pressure
extinguishers on Class K fires.
7–19
Potassium based,
low pH
Saponification
CourtesyofRonMoore/McKinney(TX)FD

20. Use aqueous film forming foam
(AFFF) extinguishers on Class B
fires, small fuel spills.
7–20

21. Clean agent extinguishers replaced
halogenated agents.
7–21
CourtesyofAnsulCorp.

22. REVIEW QUESTION
What are the differences between
wet chemical stored-pressure,
aqueous film forming foam (AFFF),
and clean agent extinguishers?
7–22

23. Carbon dioxide (CO2) extinguishers
discharge as a gas and are most
effective on Class B and C fires.
7–23

24. CO2 is stored under its own pressure
and is discharged through a plastic or
rubber horn.
7–24
O2
CO2
Dry ice crystals
• Smothers fire
• Little cooling effect
• Reignition possible

25. CAUTION!
When carbon dioxide is discharged, a
static electrical charge builds up on the
discharge horn. Touching the horn
before the charge has dissipated can
result in a shock.
7–25

26. Operate wheeled (CO2) extinguishers
in the same manner as handhelds.
7–26
CourtesyofBadgerFireProtection
Commonly found in
airports and
industrial facilities

27. Dry chemical extinguishers use
additives to keep extinguishing agents
ready for use, even after long storage
periods.
7–27

28. Dry chemical extinguishers may react
chemically with other types of
extinguishing agents.
7–28

29. WARNING!
Never mix or contaminate dry chemicals
with any other type of agent.
7–29

30. Dry chemical agents are
considered nontoxic and safe for
use.
7–30

31. Follow these steps when using dry
chemical extinguishers on Class A
fires.
7–31

32. Handheld dry chemical
extinguishers come in two basic
designs.
7–32

33. CAUTION!
When pressurizing a cartridge-type
extinguisher, do not place your head or
any other part of your body above the
top of the extinguisher. If the fill cap was
not properly screwed back on, the cap
and/or a cloud of agent can be forcibly
discharged.
7–33

34. Wheeled dry chemical
extinguishers operate in a similar
manner as handheld cartridge-
types.
7–34
Agent
Pressurizing
gas
Stretch out hose completely;
powder can clog
Allow few seconds to pressurize
after introducing gas
Prepare for significant
nozzle reaction

35. CAUTION!
The top of the extinguisher should be
pointed away from the operator and any
other nearby personnel when
pressurizing the unit.
7–35

36. Use dry powder extinguishers on
fires for Class D metals.
7–36

37. Dry powder creates a smothering
blanket over burning area.
7–37

38. CAUTION!
Water applied to a combustible metal
fire results in a violent reaction that
intensifies the combustion and causes
bits of molten material to spatter in
every direction.
7–38

39. Follow these steps if burning metal
is on a combustible surface.
7–39

40. REVIEW QUESTION
How do carbon dioxide (CO2), dry
chemical, and dry powder
extinguishers differ?
7–40

41. Define the ratings in a portable fire
extinguisher rating system.
Learning Objective 3
7–41

42. Fire extinguishers are rated
according to performance
capability.
7–42
(Cont.)

43. Fire extinguishers are rated
according to performance
capability.
7–43

44. Fire extinguishers rated for multiple
classes of fire are identified by a
combination of letters.
7–44

45. Fire extinguishers are identified
by colored geometric shapes or
pictographs.
7–45

46. REVIEW QUESTION
How are the ratings used for
portable fire extinguishers
determined?
7–46

47. Explain the considerations taken
when selecting and using portable fire
extinguishers.
Learning Objective 4
7–47

48. Fire extinguishers are chosen to
achieve two main goals.
7–48

49. Consider several factors when
selecting the proper fire extinguisher.
7–49

50. Use clean agent or CO2 extinguishers
in areas with computer equipment.
7–50
Dry chemicals
can be damaging

51. Operating procedures for all fire
extinguishers are similar, but be
familiar with label instructions.
7–51
CourtesyofAnsulCorp.

52. Note
Wear full structural or wildland fire
fighting personal protective equipment
including appropriate respiratory
protection when operating any portable
fire extinguisher. Even small incipient
fires will produce toxic gases that can
injure you.
7–52

53. After you select the extinguisher
make a quick visual inspection.
7–53

54. Follow these general steps for
using fire extinguishers.
7–54
(Cont.)

55. Follow these general steps for
using fire extinguishers.
7–55
• If not extinguished after full discharge, withdraw
and reassess
• If solid fuel, use appropriate tool to overhaul
• If liquid fuel, appropriate foam may be necessary

56. Remember the following
considerations when using
extinguishers.
7–56

57. REVIEW QUESTION
When using a portable fire
extinguisher, how can you determine
the best way to use it?
7–57

58. Identify procedures used for the
inspection, care, and maintenance of
portable fire extinguishers.
Learning Objective 5
7–58

59. Inspection, care, and maintenance of
extinguishers are mandated by a
number of organizations.
7–59

60. NFPA®
10 requires at least an annual
inspection; local SOPs establish
policy.
7–60

61. Follow these general procedures
for every extinguisher inspection.
7–61
(Cont.)

62. Follow these general procedures
for every extinguisher inspection.
7–62

63. Follow these steps if any
extinguishers are found to be
deficient.
7–63

64. Follow these general guidelines
when caring for extinguishers.
7–64
(Cont.)

65. Follow these general guidelines
when caring for extinguishers.
7–65

66. Clean extinguishers periodically
and after every use.
7–66

67. Extinguishers should be removed
from service for annual
maintenance.
7–67

68. CAUTION!
Never attempt to repair the shell or
cylinder of a defective fire extinguisher.
Contact the manufacturer for
instructions on where to have it repaired
or replaced.
7–68

69. REVIEW QUESTION
What are the basic procedures for
the care and maintenance of portable
fire extinguishers?
7–69

70. • Portable fire extinguishers can control
or extinguish small incipient or early
growth stage fires quickly in the hands
of trained personnel; you must be
familiar with their characteristics and be
able to select and use them properly.
Summary
7–70
(Cont.)

71. • Not only should you be familiar with
their characteristics and be able to
select and use them properly, you must
also be able to educate the public.
• Inspecting, caring for, maintaining
extinguishers assigned to your
apparatus and facility are also
important skills for you to have.
Summary
7–71

72. Operate a stored-pressure water
extinguisher.
This objective is measured in Skill
Sheet 7-I-1.
Learning Objective 6
7–72

73. Operate a dry chemical (ABC)
extinguisher.
This objective is measured in Skill
Sheet 7-I-2.
Learning Objective 7
7–73

74. Operate a carbon dioxide (CO2)
extinguisher.
This objective is measured in Skill
Sheet 7-I-3.
Learning Objective 8
7–74