Polybrominated dibenzofurans and dibenzo-p-dioxins: thermal reaction products of polybrominated diphenyl ether flame retardants.

Thermolysis of three technical polybrominated diphenyl ether (PBDPE) flame, retardants in quartz minivials at 510-630/sup 0/C produced a range of potentially hazardous and toxic polybrominated dibenzofurans (PBDFs) and di-benzo-p-dioxins (PBDDs) at total yields of up to 10%. HRGC-MS analysis revealed the formation of various mono- to octabrominated species. EI mass spectra of PBDPEs, PBDFs, and PBDDs were found to be similar to those of the chlorinated analogues. The technical PBDPEs, consisting of a rather small number of components, lead to reasonably simple mixtures of reaction products with, often, one or two main PBDF and PBDD isomers. Except 2,3,7,8-tetrabromodibenzofuran, which was not among the main thermolysis products, isomer assignments were not possible due to the lack of authentic reference compounds. PBDPEs are of environmental concern; the formation of PBDFs and PBDDs is of additional concern. These adverse effects should be carefully evaluated against the possible merits of these products as flame retardants. 20 references, 2 figures, 4 tables.