Halogens

The next heaviest element in the halogen family is bromine, named from a Greek word for stink, because of its strong and disagreeable odor. It was first isolated as an element in 1826. Bromine is a reddish brown liquid that vaporizes easily. The vapors are irritating to the eyes and throat. Elemental bromine is made by oxidation, removal of electrons from bromide ions in brine. Brines in Arkansas and Michigan, in the United States, are fairly rich in bromide. Other world-wide sources are the Dead Sea and ocean water.

There are a variety of applications for bromine compounds. The major use at one time was in ethylene dibromide, an additive in leaded gasoline. This need has declined with the phase-out of leaded fuel. Several brominated organic compounds have wide utilization as pesticides or disinfectants. Currently the largest volume organic bromine product is methyl bromide, a fumigant. Some medicines contain bromine, as do some dyes.

Halons, or halogenated carbon compounds, have been utilized as flame retardants. The most effective contain bromine, for example, halon 1301 is CBrF₃. Inorganic bromine compounds function in water sanitation, and silver bromide is used in photographic film. Bromine also appears in quartz-halide light bulbs.