Halon 1211 is a trade name for Bromochlorodifluoromethane, it is also known as BCF,Halon 1211 BCF, or Freon 12B1. The chemical formula is CF₂ClBr.

It introduced as an effective gaseous fire suppression agent in the 1960s, and was used around highly valuable materials such as in museums, mainframe rooms, and telecommunication switching centers. Production of Bromochlorodifluoromethane and similar Chlorofluorcarbons have been banned since January 1, 1994 in most countries due to the Montreal Protocol on ozone depleting substances.

This is a volatile extinguishant that should be used only with a breathing apparatus (when volume exceeds 5%).

See also: Halon 1301, fire extinguisher