Halon

Halon (short for halogenated hydrocarbon) is an is an artificial liquefied gas and scheduled substance that is used to extinguish fire by chemically interrupting the combustion chain reaction. As a scheduled substance halon is a prescribed ozone depleting substance and synthetic greenhouse gas that is known to adversely affects the Earth's ozone layer.

Halons have relatively long lifetimes in the atmosphere and are broken down in the stratosphere releasing reactive bromine that is extremely damaging to ozone. This poses an unacceptable risk to the earth for their effect on global warming.

It is nonconducting and described as a "clean agent," as it leaves no residue after being discharged. There are two forms of Halon used in fire protection;

• Halon 1211 also known as BCF a liquid streaming agent and sold in the form of a YELLOW portable or wheeled fire extinguisher; and
• Halon 1301 also known as BTM is a flooding agent and has been used in the past as part of a gaseous fire suppression system.

Halons ceased being used for fire safety by the end of 1992.