What is "bromochloromethane"

n. (context organic compound English) The halogenated hydrocarbon CH₂BrCl once used in fire extinguishers

Bromochloromethane or methylene bromochloride and Halon 1011 is a mixed halomethane. It is a heavy low-viscosity liquid with refractive index 1.4808.

It was invented for use in fire extinguishers by the Germans during the mid-1940s, in an attempt to create a less-toxic, more effective alternative to carbon tetrachloride. This was a concern in aircraft and tanks as carbon tetrachloride produced highly toxic by-products when discharged onto a fire. CBM was slightly less toxic, and used up until the late 1960s, being officially banned by the NFPA for use in fire extinguishers in 1969, as safer and more effective agents such as halon 1211 and 1301 were developed. Due to its ozone depletion potential its production was banned from January 1, 2002, at the Eleventh Meeting of the Parties for the Montreal Protocol on Substances that Deplete the Ozone Layer.

It can be biologically decomposed using the hydrolase enzyme alkylhalidase by the reaction:

CHBrCl (l) + HO (l) → CHO (l) + Br (l) + Cl (g)