Brominated organic micropollutants - Igniting the flame retardant issue

There is increasing concern over the toxicity and environmental distribution of a number of classes of brominated compounds such as polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs) used as flame retardants as well as brominated and mixed bromochloro dibenzo-p-dioxins and dibenzofurans (PBDD/Fs and PBrClDD/Fs). Observed ubiquity and bio-accumulative characteristics coupled with dioxin-like toxicity have led to some of these compounds being classified as POPs. Unlike chlorinated dioxins the levels of brominated compounds in the environment shows an increasing trend. The main pathway to observed human exposure is probably through food. The European Commission has reviewed the use of some of these compounds and has recommended a ban on some commercial mixtures. There is corresponding legislation in individual countries against production and usage. This article reviews the ecological and environmental impact of the use of PBDEs, PBBs and other brominated flame retardants. Attention is given to the properties of individual PBDE and PBB congeners as well as the more toxic PBDD/Fs and PBrClDD/Fs. Occurrence, source, fate, toxicology, exposure, analysis and future work required is assessed for each class of brominated organic micropollutant (BOM) outlined.