Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:1:p7
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 1 (pt 7/14)
Character Range: 2702552–2705548

Biphenyls: Human Health Aspects, World Health Organization, Geneva.

    2                   Polybrominated Diphenyl Ethers (Br1 to Br9)

2.1              General
Polybrominated diphenyl ethers (PBDE) are a group of compounds manufactured for their flame retardant properties. They consist of two phenyl groups bound to a single oxygen atom with the hydrogen atoms on the phenyl groups substituted with between one and ten bromine atoms. The group consists of 209 congeners, which differ in the number and location of substituted bromine atoms. The internationally accepted numbering system for PBDE congeners is the acronym 'BDE' followed by a number from 1 to 209 (NICNAS 2007).

Several comprehensive reviews of PBDEs in the environment and their toxicity to humans are available and should be consulted for more detailed information not presented in this summary (ATSDR 2004; NICNAS 2007; UNEP 2009). The following provides a summary of the key aspects of these compounds that are relevant to the derivation of a soil HIL.

The literature to date indicates that the toxicity and environmental fate of PBDEs with a lower number of substituted bromine atoms (penta‑BDE to hexa‑BDE) is different from higher brominated BDEs (deca‑BDE to BDE‑209). Lower brominated BDEs have been demonstrated to be more toxic in animal studies, have a higher bioavailability and are more readily transported in the environment. As a result, ATSDR has recommended separating deca‑BDE from lower brominated BDEs (ATSDR 2004). For the purpose of this assessment, lower brominated BDEs are considered to be BDEs containing between one and nine substituted bromines and it is these lower brominated BDEs for which HILs have been derived.

It is noted that the toxicity of higher BDEs is less certain, hence if significant levels of PBDE that include higher BDEs are present, a site‑specific assessment should be conducted.

Further studies regarding the toxicity and environmental fate of lower brominated BDEs may result in this grouping being revised to a smaller proportion of significant congeners in future reviews.

PBDE are manufactured compounds, which have been widely used in industrial and consumer applications. A review of the compounds conducted by scientific and regulatory bodies has culminated in tetra‑ and penta‑BDEs (components of technical penta‑BDE) and hexa‑ and hepta‑BDEs (components in technical octa‑BDE) being listed as a Persistent Organic Pollutants (POPs) under the Stockholm Convention in May 2009 (UNEP 2009). All production and use of these compounds has subsequently been banned, with the exception of recycling activities (UNEP 2009). PBDEs are not manufactured in Australia but were historically imported and used until 2005 (NICNAS 2007). Importation of products pre‑treated with PBDEs is expected to decrease following the recent ban. Technical penta‑BDE was mainly used in polyurethane foams (such as in furnishings) whereas technical octa‑BDE and deca‑BDE were mainly used in