Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:7:p1
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 7 (pt 1/4)
Character Range: 1626094–1628998

7                   Copper

7.1              Copper compounds considered
The following compounds were considered in deriving the SQGs for Cu:
    * copper metal (CAS No. 7440-50-8)
    * copper (II) sulphate pentahydrate (CAS No. 7758-98-7)
    * copper (I) oxide (CAS Nos 1317-3-1)
    * copper (II) oxide (CAS No. 1317–38–0)
    * dicopper chloride trihydroxide (CAS No. 1332-65-6).

7.2              Exposure pathway assessment
The two key considerations in determining the most important exposure pathways for inorganic contaminants are whether they biomagnify and whether they have the potential to leach to groundwater.

A surrogate measure of the potential for a contaminant to leach is its watersoil partition coefficient (Kd). If the logarithm of the Kd (log Kd) of an inorganic contaminant is less than 3, then it is considered to have the potential to leach to groundwater (Schedule B5b). The Australian National Biosolids Research Program measured the log Kd of Cu in 17 agricultural soils throughout Australia. These measurements showed that, in most soils, the log Kd of Cu was below 3 L/kg (unpublished data). The log Kd value for Cu reported by Crommentuijn et al. (2000) was 2.99 L/kg. Therefore, there is the potential for Cu in some soils to leach to groundwater and affect aquatic ecosystems. However, the methodology for SQG derivation (Schedule B5b) does not advocate the routine derivation of SQGs that account for leaching potential. Rather, it advocates that this be done on a site-specific basis as appropriate (Schedule B5b).

Copper is an essential element for the vast majority of living organisms and, as such, concentrations of Cu in tissue are highly regulated and it does not biomagnify (Louma & Rainbow 2008; Heemsbergen et al. 2008; EC 2008a). Therefore, the biomagnification route of exposure does not need to be considered for Cu and the SQGs will only account for direct toxicity.

7.3              Toxicity data
The ecotoxicology of Cu has been extensively studied both within Australia and internationally. Most studies presented their toxicity data as an added concentration (that is, the concentration of the contaminant added to the soil that causes a specified toxic effect) or in a form that permitted the added concentration to be calculated (that is, by subtracting the background from the total concentration).

The toxicity database used to calculate the SQGs for Cu consisted of over 400 toxicity measures for 11 soil processes (Table 47), 10 invertebrate species (Table 48) and 18 plant species (Table 49). The raw data used to generate Tables 4749 is provided in Appendix E. There was sufficient data—that is, toxicity data for at least five species or soil processes that belong to at least three taxonomic or nutrient groups (Schedule B5b)—available to derive SQGs using a species sensitivity distribution (SSD) methodology.

Given that Cu does not