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� Class C Materials: This refers to electrical materials and equipment that can cause fires quickly and
present a serious risk of arc flash due to electrical faults.
� Class D Materials: Materials in this class are volatile and can ignite rapidly. Examples include metals like
magnesium, potassium, and sodium, which are highly reactive and combustible.
� Class K Materials: This refers to cooking oils and fats typically found in commercial kitchens or places where
large-scale cooking operations occur. These materials are characterised by their high heat content and
ability to ignite easily, often leading to fires that can be challenging to extinguish with traditional methods.
Understanding these classifications helps in assessing fire risks, implementing appropriate safety measures,
and responding effectively to prevent or mitigate fires based on the properties and behaviors of different
materials.
Examples of ignition sources categorised by their nature:
� Open Flames: Examples include gas ovens, lighters in smoking areas, and welding torches.
� Sparks: Generated from activities like wood or metal sawing, grinding, or other types of equipment that
produce friction.
� Heat Sources: These encompass combustion engines, space heaters, ovens, and machinery that generate
heat during operation.
� Chemical Ignition: Certain chemicals can combust under normal working temperatures, contributing to
fire risks.
Here's a table summarising the classes of fire and the suitable fire extinguishers for each class:
CLASS OF FIRE DESCRIPTION SUITABLE FIRE EXTINGUISHERS
Class A Ordinary combustible (wood, paper, cloth) Water, Foam
Class B Flammable liquids (gasoline, oil, grease) Dry Chemical, CO
2
Class C Electrical equipment CO
2
Class D Combustible metals (magnesium, titanium) Specialised Dry Powder
Class K Cooking oils and fats Wet Chemical
Fire Extinguisher
Discharge Discharge
A fire extinguisher is a portable device designed Locking Pin Lever
and Seal
for active fire protection, filled with dry or wet
Carrying
chemicals to extinguish or control small fires in Pressure Gauge Handle
(not found on CO
emergencies. It is not meant for use on fires that extinguishers) 2
are out of control, such as those reaching the
ceiling, posing risks like no escape route, smoke, Discharge Body
or explosion hazards. Fire extinguishers usually Hose
feature a handheld cylindrical pressure vessel Data
Plate
holding an extinguishing agent.
Using a fire extinguisher effectively involves
following a straightforward method known as the
PASS technique. Here are the steps: Discharge
Step 1: Pull the pin or safety clip located at the Nozzle
top of the fire extinguisher. This step
prepares the extinguisher for use.
Prevent Accidents and Emergencies 305

