halon

noun

1. any of a class of chemical compounds derived from hydrocarbons by replacing one or more hydrogen atoms by bromine atoms and other hydrogen atoms by other halogen atoms (chlorine, fluorine, or iodine). Halons are stable compounds that are used in fire extinguishers, although they may contribute to depletion of the ozone layer

1. Any of several compounds consisting of one or two carbon atoms combined with bromine and one or more other halogens. Halons are gases and are used as fire-extinguishing agents. They are between three and ten times more destructive to the ozone layer than CFCs are.