74 Auto Fundamentals
Fires Type Use
Class A Fires
Ordinary Combustibles
(Materials such as wood,
paper, textiles.)
Requires...
cooling-quenching
Class B Fires
Flammable Liquids
(Liquids such as grease,
gasoline, oils, and
paints.)
Requires...blanketing or
smothering.
Class C Fires
Electrical Equipment
(Motors, switches, etc.)
Requires...
a nonconducting agent.
Class D Fires
Combustible Metals
(Flammable metals such
as magnesium and
lithium.)
Requires...blanketing or
smothering.
Soda-acid
Bicarbonate of
soda solution
and sulfuric
acid
Pressurized Water
Water under
pressure
Carbon Dioxide (CO2)
Carbon dioxide
(CO2) gas
under pressure
Foam
Solution of
aluminum
sulfate and
bicarbonate
of soda
Dry
Chemical
Dry Chemical
Granular type material
Not for use on
Okay for use on
Not okay for Not okay for
Okay for Okay for
Multi-purpose
type
Ordinary BC
type
Not for use on
Not for use on
Not for use on
Not for use on
Okay for use on
Okay for use on
Okay for use on
Okay for use on
Operation
Direct stream at base of
flame.
Direct stream at base of
flame.
Direct discharge as
close to fire as possible,
first at edge of flames
and gradually forward
and upward.
Direct stream into the
burning material or
liquid. Allow foam to
fall lightly on fire.
Direct stream at base of
flames. Use rapid left-
to-right motion toward
flames.
Smother flames by
scooping granular
material from bucket
onto burning metal.
A
B
C
D
A
A
A
A
A
B C D
B
B
B
B
C
C
C
C
D
D
D
D
A
D
B
C
A
D
B C
Old New
Old New
Old New
Figure 4-6.
This chart illustrates the various fi re classifi cations and fi re extinguisher types. In the automotive repair shop,
extinguishers designed for chemical and electrical fi res (multipurpose or ABC types) should be used.
Goodheart-Willcox Publisher