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BROMINATED FLAME RETARDANTS: WHAT WE KNOW, AND WHAT WE DON’T
Citation:
BIRNBAUM, L. S. BROMINATED FLAME RETARDANTS: WHAT WE KNOW, AND WHAT WE DON’T. Presented at Regional Laboratory Technical Group Conference, Chicago, IL, May 01, 2007.
Impact/Purpose:
BFR presentation
Description:
Brominated flame retardants (BFRs) represent a large and diverse class of high volume industrial chemicals which have been developed to provide fire safety. There are many other BFRs which have been used and are under development. Historically, polybrominated biphenyls (PBBs) were used but they were banned because of their persistence, bioaccumulation, and toxicity. Some of these are being detected in environmental samples. The three major BFRs in use today are tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD) and the polybrominated diphenyl ethers (PBDEs), which involves three commercial mixtures, Penta, Octa, and the only one still in production, Deca. TBBPA is the largest volume chemical and is used both as an additive and reactive flame retardant, primarily in electronics. It has moderate persistence, little bioaccumulation, and relatively low concern for toxicity, although it may have some endocrine disrupting properties. HBCD is also used in electronics, but is more persistent and bioaccumulative. Its isomeric composition changes as it undergoes fate, transport, and metabolism. It is found in increasing concentrations in wildlife and human samples, and there is growing concern for its potential toxicity. The PBDEs are also additive BFRs, but their properties and uses differ. Penta was used largely in polyurethane foam; Octa in office equipment; and Deca in polymers for electronic equipment and textile backings. Increasing concentrations of PBDE congeners have been found in environmental samples, wildlife, and people. The congeneric profile in biota differs from that in the commercial mixtures. The major pathways to human exposure are uncertain, although both dust and food are likely. Penta and Octa have been banned in Europe, and production withdrawn in the US, in part because of growing concern for their toxicity, including enzyme induction, endocrine disruption, and developmental reproductive and neurotoxicity. Deca is the major use PBDE product worldwide. Recent studies have demonstrated that it can be broken down in the environment by light and microbes, and metabolically in mammals. Some concerns for its toxicity, or that of its breakdown products, come from reports of its carcinogenicity in two year rodent studies and developmental neurotoxicity. Recently, it has been detected in wildlife and people. Alternatives are being suggested and use. Questions remain about their safety, as well as that of the existing BFRs. (This abstract does not reflect Agency policy.)