Risk assessment of polybrominated biphenyls and polybrominated diphenyl ethers

Abstract

in the present report a risk assessment of polybrominated flame retardants carried out by the Dutch ministry of Housing, Spatial Planning and the Environment in 1990 is evaluated in the view of new information. The assessment focusses on three aspects on which the following is concluded: 1) One can expect an increase in polybromodibenzodioxins, polybromodibenzofurans and their chlorinated analogs (PBDD/F and PCDD/F, respectively) formation in MWI plants as a consequence of the growing use of brominated flame retardants in plastics. However, it is not possible to draw strict conclusions from this supposition. First of all, it is not evident that the use of brominated flame retardants will increase. Then, since the products of incineration in MWI plants form a complex function of process conditions, no calculations input/yield can be done. 2) Although informations is very scarce decabromodphenyl ether (DeBDE) can be classified as a persistant chemical. Photodegradation in water has been schown but will probably not be an important route since most of the DeBDE ends up in the sediment where the sunlight intensity is low. Biodegradation, aerobic as well as anaerobic, has not been studied. Both routes may occur but it an be expected that the rates will be very low. 3) Biomagnification of commercial pentabromodiphenylether (PEBDE) does occur in significant quantities. Based on actual levels in fish and sediment it can be stated that these levels are always below the Maximum Permissible Concentration taking into account secondary poisoning of predators via consumption of fish. The Negligible Concentration is exceeded by at least a factor 10, however.