Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:4:p24
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 4 (pt 24/24)
Character Range: 1006764–1007775

a relevant exposure pathway'.

Where the inhalation of dust is of importance in a risk assessment, it may be appropriate to use route extrapolation of oral TRVs for the assessment of TPH C16-C36 (aliphatic and aromatic fraction).

HSLs have been developed for benzene, toluene, ethyl benzene, xylenes, naphthalene, and petroleum hydrocarbon fractions (C6-C10, >C10-C16, >C16-C34 and >C34) in soil, soil vapour and groundwater for use where the key contaminants are petrol and/or diesel. The TPH HSLs were derived using TPHCWG aromatic and aliphatic fractions. Where other products (for example, aviation fuels, fuel oils, kerosene) are present, analysis of the aromatic and aliphatic fractions separately is necessary to determine the composition, since this can have a significant impact on the risk.

Where phase-separated hydrocarbon is present, a site-specific assessment of vapour risk including analysis of the aromatic and aliphatic fractions may be necessary (for further information see Section 4.4.6).