Fire Extinguishers

Water Fire Extinguishers:
The cheapest and most widely used fire extinguishers. Used for Class A fires. Not suitable for Class B (Liquid) fires, or where electricity is involved.
Foam Fire Extinguishers: Slightly more expensive than water, but more versatile. Used for Classes A & B fires. Foam spray extinguishers are not recommended for fires involving electricity, but are safer than water if inadvertently sprayed onto live electrical apparatus.
Dry Powder Fire Extinguishers: Often called the ‘multi-purpose’ extinguisher, as it can be used on classes A, B & C fires. Best for running liquid fires (Class B). Will efficiently extinguish Class C gas fires, 
CO2 Fire Extinguishers:
Carbon Dioxide is ideal for fires involving electrical apparatus, and will also extinguish class B liquid fires, but has NO POST FIRE SECURITY and the fire could re-ignite.
Wet chemical
Specialist extinguisher for class F fires.