Fire extinguishers are only valuable safety devices when you
know how to use them. This is why we offer training in the use of
fire extinguishers and provide information on this Web site to help
you learn about the ABCs
of fire extinguishers, and how to perform visual inspections
and decide whether or not to attempt to fight a fire. We encourage
you to call us to schedule a fire extinguisher training session
today.
Know Your Fire Extinguisher ABCs
Fires are classified based on the type of fuel involved.
Likewise, portable fire extinguishers are classified by the type of
fires they are designed to extinguish. There are five basic
classifications of fuel and extinguishers, and extinguishers are
labeled with either letter-shaped or pictorial symbols that
indicate what types of fires they are intended
for.
Classifications of Fires and
Extinguishers
Class A
Class A fires involve ordinary combustible materials, such as
cloth, wood, paper, rubber, and many plastics. Extinguishers with
an A rating are designed to extinguish fires involving these
ordinary combustible materials.
Class B
Class B fires involve flammable and combustible liquids such as
gasoline, alcohol, oil-based paints, lacquers. Therefore,
extinguishers with a B rating are designed to extinguish fires
involving flammable and combustible liquids.
Note: Do not attempt to extinguish a fire involving flammable
gas unless there is reasonable assurance the source of fuel can be
promptly shut off. In fact, if the only fuel burning is the leaking
gas, the best method for extinguishing the fire is to shut off the
fuel supply. Extinguishing a flammable gas fire, without shutting
off the fuel, will allow unburned gas to escape into the
atmosphere, which may permit a dangerous accumulation of gas to
develop, and an explosion may occur if the gas is exposed to an
ignition source.
Class C
Class C fires involve energized electrical equipment.
Extinguishers with a C rating are designed for use with fires
involving energized electrical
equipment.
Class D
Class D fires involve combustible metals, such as magnesium,
titanium, and sodium. Extinguishers with a D rating are designed to
extinguish fires involving combustible metals.
Note: Common extinguishing agents may react with a combustible
metal fire causing the severity of the fire to increase. The most
common method for extinguishing a combustible metal fire is to
cover the burning material with a dry powder, such as sand, which
will not react with the material. If you store or use combustible
metals, contact the Fire Prevention Services office for a
consultation regarding the proper type and amount of extinguishing
agent you should have available.
Class K
Class K fires involve vegetable oils, animal oils, or fats in
cooking appliances. Extinguishers with a K rating are designed to
extinguish fires involving vegetable oils, animal oils, or fats
utilized in commercial cooking appliances.
Note: Extinguishers with a K rating are normally required where
deep-fryers and/or griddles are utilized to prepare large
quantities of food. An example would be a commercial kitchen
similar to those found in restaurants and
cafeterias.
Multipurpose Extinguishers
Most portable extinguishers are rated for use with more than one
classification of fire. For example, an extinguisher with a BC
rating is suitable for use with fires involving flammable liquids
and energized electrical equipment. An extinguisher with an ABC
rating is suitable for use with fires involving ordinary
combustibles, flammable liquids and energized electrical equipment.
An extinguisher that is rated for use with multiple hazards should
include a symbol for each hazard type.
