The incidence of fire-related injuries, deaths, and economic damages has decreased over the past 25 years, partly because of fire prevention policies requiring flame retardant chemicals in many industrial products. Brominated flame retardants (BFRs) have routinely been added to consumer products for several decades to reduce fire-related incidents. They represent a major industry involving high-production chemicals with a wide variety of uses, yet all BFRs are not alike and often the only thing that they have in common is the presence of bromine. Concern for this emerging class of chemicals has been raised following a rapid increase of levels in the environment, wildlife, and people in combination with reports of developmental, reproductive and neurotoxicity, and endocrine disruption. Despite these concerns, little information is available on their sources, environmental behavior, and toxicity. Because of limited knowledge, few risk assessments have been completed.
More than 175 different types of flame retardants are commercially available and can be generally divided into classes that include halogenated organic (usually brominated or chlorinated), phosphorus- or nitrogen-containing, and inorganic flame retardants. The BFRs are currently the largest market group because of their low cost and high efficiency. Some, such as the polybrominated biphenyls (PBB), are no longer being produced because of recognized toxicity and accidental poisoning.1 “Tris-BP” was also removed from the market after its original use as a flame retardant on children's clothing because it was shown to have mutagenic and nephrotoxic effects.2
Over 75 BFRs are recognized; however, five BFRs constitute the overwhelming majority of BFR production. Tetrabromobisphenol A (TBBPA), hexabromocylododecane (HBCD), and three commercial mixtures of polybrominated diphenyl ethers, or biphenyl oxides, known as decabromodiphenyl ether (DBDE), octabromodiphenyl ether (OBDE), and pentabromodiphtnyl ether (PentaBDE), are used as additive or reactive components in a variety of polymers. The spectrum of final applications is very broad, but includes domestic and industrial equipment such as: TVs, mobile phones, computers, furniture, insulation boards, carpet padding, mattresses, and upholstered textiles. About 90% of electrical and electronic appliances contain BFRs. Information on global production and usage of BFRs is supplied by the Bromine Science and Industrial Forum.3
Global environmental studies indicate that these chemicals are ubiquitous in sediment and biota and undergo long range transport.4,5 All of the major BFRs (PBDEs, HBCD, and TBBPA) have been documented in air, sewage sludge, sediment, invertebrates, birds, and mammals (including humans). Environmental trends show that levels are increasing and that often the specific congener patterns found in biota do not mimic what is used in commercial products. This suggests breakdown or transformation of the flame retardant products during manufacture, use, disposal, or during biomagnification in the food web. Full documentation and specific concentrations in the various media can be found in special issues of the journals Chemosphere4 and Environment International.5