Smothering is a method of extinguishing a fire by removing the oxygen in the atmosphere, thus extinguishing the fire. This can be achieved by using sand, blanketing, foam application, or introducing carbon dioxide (CO2) to the fire. Smothering can also be achieved by cutting off the supply of oxygen or access of fresh air into the fire using sand, foam, or other materials to cover the fire. Smothering is one of the most effective methods of extinguishing a fire, especially for commercial fires large and small.