Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:2:p5
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 2 (pt 5/21)
Character Range: 51924–55132

for general site assessment and sub-slab environments for evaluation of potential health risks for the 01 m sub-slab profile. The interim HILs broadly apply to the same generic land use categories as do the HILs, though  the values for residential A and B are combined as they are based on the same exposure conditions (i.e. the same amount of time spent indoors) for the vapour inhalation pathway.  In addition, secondary school buildings should be treated as residential for the purposes of evaluating risks from vapour intrusion.

Biodegradation of VOCCs has not been included in the development of the interim HILs. The biodegradation approach developed for petroleum hydrocarbons (refer Section 2.4.10) is not applicable to the degradation of VOCCs as the mechanism by which degradation occurs is different for most chlorinated hydrocarbons compared with petroleum hydrocarbons.

2.4              Health screening levels for petroleum hydrocarbon compounds

    2.4.1          Introduction
Site contamination by petroleum hydrocarbon compounds is frequently encountered. The complex mixtures of aliphatic and aromatic compounds that comprise petroleum hydrocarbon products present human health concerns predominantly through inhalation of vapours from contaminant sources and by direct contact with affected soils and groundwater. Assessment of petroleum impacts should include evaluation of risks via the groundwater pathway (e.g. consumption of contaminated groundwater that is not considered in the HSLs), the risk to groundwater resources and appropriate consideration of aesthetics. The application of relevant ecological and 'management' criteria for petroleum compounds is discussed in Sections 2.6 and 2.9.

Health Screening Levels (HSLs) for various petroleum hydrocarbon compounds were developed by the Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE). The principal reference for the HSL methodology is Friebel and Nadebaum (2011a). In addition to the documentation of the methodology, a detailed application report (Friebel & Nadebaum 2011b) and a sensitivity analysis of the main parameter inputs ((Friebel & Nadebaum 2011c) are available.

Predictive modelling of sub-surface vapour movement in soil and penetration of building structures is a field of intensive data collection and research. The most recent research and derivation approaches adopted in developed international jurisdictions have been considered and adapted, as far as is practicable, for Australian conditions, to derive Tier 1 screening criteria for evaluating human health risk from petroleum hydrocarbons.

The HSLs' development was guided by a project advisory group with health, environmental, assessment and remediation, petroleum industry and regulatory expertise. A specialised technical working group provided technical support and review throughout the development process. The HSL methodology was subject to international peer review during its development.

Copies of the technical reports can be found in the ASC NEPM Toolbox. Additional information on the development phases of the project, including responses to peer review comments, can be found on