There are three important elements that can cause fire- heat, oxygen, fuel. Fire extinguishers work by eliminating one or two of these elements. They are the following:
1. Water and foam: water works by eliminating the heat element. It is better to use water only for wood, paper, cloth, trash, and plastics. Foam can be used for wood, paper, cloth, trash, and plastics, oils, gasoline, paraffin, petroleum paint and gases.
2. Carbon dioxide: It works by eliminating two components, cutting off the oxygen supply and heat by cold discharge.
3. Dry chemicals: It is effective in case of wood, paper, cloth, trash, plastics, oils, gasoline, paraffin, petroleum paint, gases and electric equipments (motor, transformers, and other electrical appliances). It creates a barrier between oxygen and fuel, and hence, puts off the fire.
4. Wet chemicals: They work in case of kitchen fires, ignited by cooking oils, greases, animal and vegetable fat, etc.
