Gas, a fuel. Natural gas is taken from underground deposits where it has been trapped for centuries. Manufactured gases are produced by any of several methods discussed later in this article.
Gas provides the world, and especially the United States, with a large part of its total fuel energy. In many homes it is burned for heating and cooking. It can also be used for incinerating waste, for powering motor vehicles, and for operating air conditioners, clothes driers, water heaters, and refrigerators. In industry, gas is burned to provide heat for hundreds of different processes. Gas was formerly widely used to light streets and buildings.
Gas has many advantages as a fuel. It can easily be made to flow from one place to another, and it is easily stored by the utility companies that supply it. Most consumers do not need to store gas, but may rely on a steady, uninterrupted flow of the fuel from the utility company. When ignited, gas burns evenly and completely.
Gas may be an explosion hazard if allowed to concentrate in unventilated rooms. Natural gas is not toxic (poisonous), but can cause death by suffocation if allowed to replace the air in a room. Improvements in the design of gas equipment have greatly reduced the chances of gas leaks. Modern gas-burning equipment has many safety features, including automatic cutoff devices that stop the flow of fuel. Gas properly handled, in equipment installed and checked by a utility company, is safe.
