Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:1:p8
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 1 (pt 8/14)
Character Range: 2705278–2708196

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 hard plastics (such as for electrical equipment) (NICNAS 2007). The articles treated with PBDEs usually have long lives and, as such, articles containing PBDEs are still expected to be in use (NICNAS 2007). Deca‑BDE was declared a priority existing chemical in Australia and is currently being assessed as to its environment and human health risks (NICNAS 2007).

2.2              Previous HIL
No previous HIL is available for lower BDEs (NEPC 1999).

2.3              Significance of Exposure Pathways

2.3.1         Oral Bioavailability
Insufficient data is available to adequately define the bioavailability of lower BDEs, hence a default approach of assuming 100% oral bioavailability has been adopted in the derivation of an HIL. It is noted that a site‑specific assessment of bioavailability can be undertaken where required.

2.3.2         Dermal absorption
Insufficient data is available on the dermal absorption of lower BDEs from soil. Hence the default values of 0.1 (10%) suggested by US EPA (2004) for semi‑volatile organic compounds has been adopted in the derivation of HILs.

It is noted that EU (2004) estimated a dermal absorption value of 1% as a maximum for deca‑BDE, based on assumptions associated with the lipophillic nature of the compound and analogies to PCB. However, it is also noted in this review that dermal absorption may also be associated with accumulation in the stratum corneum, which may behave as a storage site, resulting in a low systemic release over time.

2.3.3         Inhalation of Dust
Lower BDEs are not considered sufficiently volatile to be of significance and inhalation exposures associated with dust particulates outdoors and indoors are expected to be of less significance than ingestion of soil. While likely to be negligible, potential inhalation exposures associated with dust have been considered in the HIL derived.

2.3.4         Plant Uptake
Limited data is available on the potential for lower BDEs to be taken up by plants from soil into edible fruit and vegetable crops. ATSDR notes that PBDEs will be strongly adsorbed to soil, hence PBDEs present in soil‑pore water will bind to soil organic matter. Because PBDEs adsorb strongly to soil, they will have very low mobility, and leaching of PBDEs from soil to groundwater will be insignificant.

Review of plant uptake of deca‑PBDE (BDE‑209) into plants from soil by Huang et al. (2010) suggests that deca‑BDE is taken up and translocated within the plants assessed (ryegrass, alfalfa, pumpkin, squash, maize and radish). Nineteen lower brominated (di‑ to nona‑) PBDEs were detected in the soil and plant samples and five hydroxylated