:Structure of three industrially significant<unk> s. From left: ethylene bromide, bromoacetic acid, and tetrabromobisphenol-A. Fire-retardants<unk> s are widely used as fire-retardants. The most prominent member is tetrabromobisphenol-A (4,4'-(1-methylethylidene)bis-(2,6-di-bromophenol), see figure). It and tetrabromophthalic anhydride are precursors to polymers wherein the backbone features covalent carbon-bromine bonds. Other fire retardants, such as hexabromocyclododecane and the bromodiphenyl ethers, are additives and are not chemically attached to the material they protect. The use of<unk>  fire-retardants is growing but is also controversial because they are persistent pollutants. Fumigants and biocides Ethylene bromide, obtained by addition of bromine to ethylene, was once of commercial significance as a component of leaded gasoline. It was also a popular fumigant in agriculture, displacing 1,2-dibromo-3-chloropropane ("DBCP"). Both applications are declining owing to environmental and health considerations. Methyl bromide is also an effective fumigant, but its production and use are controlled by the Montreal Protocol. Growing in use are<unk>  biocides used in water treatment. Representative agents include bromoform and dibromodimethylhydantoin (“DBDMH”). Some herbicides, such as bromoxynil, contain also bromine moieties. Like other halogenated pesticides, bromoxynil is subject to reductive dehalogenation under anaerobic conditions, and can be debrominated by organisms originally isolated for their ability to reductively dechlorinate phenolic compounds. Dyes Many dyes contain carbon-bromine bonds. The naturally occurring Tyrian purple (6,6’-dibromoindigo) was a valued dye before the development of the synthetic dye industry in the late 19th century. Several brominated anthroquinone derivatives are used commercially. Bromothymol blue is a popular indicator in analytical chemistry. Pharmaceuticals Commercially available<unk>  pharmaceuticals include the vasodilator nicergoline, the sedative brotizolam, the anticancer agent pipobroman, and the antiseptic merbromin. Otherwise,<unk> s are rarely pharmaceutically useful, in contrast to the situation for organofluorine compounds. Several drugs are produced as the bromide (or equivalents, hydrobromide) salts, but in such cases bromide serves as an innocuous counterion of no biological significance. Designer drugs<unk> s such as 4-bromomethcathinone have appeared on the designer drug market alongside other halogenated amphetamines and cathinones in an attempt to circumvent existing drug laws.
Organobromine compound
Organochlorine compound
Loline alkaloid
Dioxins and dioxin-like compounds
Polycyclic aromatic hydrocarbon
Polychlorinated dibenzodioxins
Corrosive substance
Polychlorinated naphthalene