Procedure : A mock fire may be created by spilling a flammable liquid like alcohol, petrol etc. and lighting it at a safe place away from the equipments and working benches.
The extinguisher is removed from the wall. Taking a proper position, the extinguisher is opened and the discharge is directed at the base of the fire starting near the edge of the fire.
The fire is driven towards the far edge until all the flames are extinguished.
The extinguisher is closed and replaced on the wall.