Bromochloromethane

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-40s, in an attempt to create a less-toxic, more effective alternative to carbon tetrachloride.