Bromine (Br)

Overview of Bromine

Bromine is a deep-red, oily liquid with a sharp odor. A member of the halogen group, it is highly reactive and toxic. Alongside mercury, bromine is one of only two elements that exist as liquids at room temperature. Its reactivity has made it important in chemical manufacturing, flame retardants, and specialized applications, though health and environmental concerns have limited some of its uses.

Uses of Bromine

Bromine compounds are employed across industries, though several uses are being phased out due to toxicity:

Flame retardants: Brominated compounds are added to plastics, textiles, and electronics to reduce flammability, though environmental concerns have restricted their use in some countries.

Fire suppression systems: Organobromides are used in halon fire extinguishers, effective in enclosed spaces like aircraft and museums where water could cause damage.

Photography: Silver bromide (AgBr) was once central to traditional film photography because of its light sensitivity.

Chemical intermediates: Bromine is used in producing dyes, insecticides, agricultural chemicals, and pharmaceuticals.

Natural Occurrence and Production of Bromine

Bromine is found in salt brines and seawater, where it occurs as bromide ions. Today, most bromine is extracted by electrolysis of concentrated brines, with major production in the United States, Israel, and China. The Dead Sea remains one of the richest commercial sources, due to its high bromide concentration.

History of Bromine

1825–1826 – Discovery: French chemist Antoine-Jérôme Balard isolated bromine by passing chlorine gas through concentrated brine from a salt marsh, producing the distinct orange-red liquid.

Earlier work: German student Carl Löwig had isolated bromine in 1825 but was unable to publish before Balard, so official credit went to Balard.

Biological Role of Bromine

Bromine has no essential biological role in humans. It is toxic and irritating to the skin, eyes, and respiratory tract. However, bromide ions are naturally present in trace amounts in living organisms, including humans.