LO 6-9 Describe the various types of fire suppression systems and explain their use

1.4. Fire Extinguisher Types

Fire Extinguisher Types

Fire extinguishers are rated by which type of fire they are suitable for: A, B, C, D, or K. There are pictograms (a small image depicting the type of burning material the fire extinguisher is recommended for) on the fire extinguisher. A letter in the pictogram also indicates the class of fire for which the extinguisher is suitable. Fire extinguishers can contain carbon dioxide, water, dry chemical, or foam. Most types of fire extinguishers are combination extinguishers capable of fighting or suppressing more than one class of fire. The most common fire extinguisher found in a commercial vehicle service facility is a combination ABC fire extinguisher Figure 38.

An ABC fire extinguisher is capable of fighting Class A, B, and C fires. An ABC fire extinguisher has three pictograms side by side showing the type of material for which the fire extinguisher is used. An ABC fire extinguisher is a dry chemical extinguisher that works by starving the fire of oxygen. There are specialized fire extinguishers for certain workplaces where other types of fires are possible or likely. These fire extinguishers may contain foam, water, wet chemicals, or inert gases. Note that battery electric vehicles will use a Class K extinguisher for fires originating in a battery.

Fire extinguishers must be inspected and certified by a registered specialist, usually on an annual basis. An inspector tags the fire extinguisher with the name of the inspector, the company performing the service, and the date of the last inspection Figure 39. The fire extinguishers should also be checked by the Joint Health and Safety Committee during each shop safety inspection, making sure the seal is intact and the pressure reading is in the normal range.

FIGURE 06-38: An ABC combination fire extinguisher.

FIGURE 06-39: A fire extinguisher inspection tag.