Methods available for fighting fires. Industrial and commercial buildings are often protected by an automatic sprinkler system: heat or smoke opens the sprinkler heads on a network of water pipes which spray the source of the fire. In circumstances where water is ineffective and may be dangerous; for example, for oil and gasoline storage-tank fires, foam systems are used; for industrial plants containing flammable vapors, carbon dioxide is used; where electricity is involved, vaporizing liquids create a nonflammable barrier; for some chemicals only various dry powders can be used.
Public fire-fighting services are usually maintained by local authorities, and similar services operate in other countries.
In small communities, volunteer fire departments and local government work together.