US EPA

The purpose of this Toxicological Review is to provide scientific support and rationale for the hazard and dose-response assessment in IRIS pertaining to chronic exposure to 2,2',4,4',5-pentabromodiphenyl ether. It is not intended to be a comprehensive treatise on the chemical or toxicological nature of 2,2',4,4',5-pentabromodiphenyl ether (BDE-99).

The majority of the available toxicological information on the pentabromodiphenyl ether homolog group (CAS No. 32534-81-9) relates to the pentabromodiphenyl congener BDE-99 (CASRN 60348-60-9). Toxicological information related to other congeners in the pentabromodiphenyl ether homolog group is also discussed. However, this health assessment does not deal with commercial mixtures of brominated diphenyl ether homologs containing pentabromodiphenyl ether as one of the constituents of commercial formulations. In addition to BDE-99, IRIS health assessments have also been prepared for three other polybrominated diphenyl ether congeners: tetraBDE-47, hexaBDE-153, and decaBDE-209. These four congeners are those for which toxicological studies suitable for dose-response assessments were available and are the ones most commonly found in the environment and human biological media.

PBDEs are used as flame retardants in furniture foam, plastics for TV cabinets, consumer electronics, wire insulation, and backcoatings for draperies and upholstery. An assessment of the potential health effects of four individual congeners of polybrominated diphenyl ethers has been undertaken. This final assessment includes reference values for the noncancer effects (RfD and RfC) and a cancer assessment, where supported by available data, for the BDE-99 congener of polybrominated diphenyl ether.

The draft assessments will present reference values for the noncancer effects (RfD and RfC) and a cancer assessment, where supported by available data, for the BDE-47, BDE-99, BDE-153, and BDE-209 congeners of polybrominated diphenyl ethers.

U.S. EPA. IRIS Toxicological Review of Pentabromodiphenyl Ether (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/635/R-07/006F, 2008.