Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:9:p2
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 9 (pt 2/4)
Character Range: 2562036–2564837

as a pesticide, however no data is available on plant uptake from soil with residual contamination of mirex. Mirex has a high Koc value (log Koc = 3.7) and low solubility in water (ATSDR 1995), suggesting that the compound is largely bound to soil particulates and is immobile in soil. For plant uptake to be significant, the chemicals must be able to partition to soil water. With respect to mirex bound to the soil, the potential for partitioning to soil water is considered to be low and hence plant uptake is considered to be negligible.

9.3.5         Intakes from Other Sources – Background
No data is available regarding background concentrations of mirex in Australia. Given the chemical's persistence in the environment, dietary intakes (particularly seafood) are expected to be of most significance for the general population. Mirex has not been detected in any food products evaluated in the 23rd Australian Total Diet Survey (FSANZ 2011). Limited data reported from the US in WHO (1984) suggest intakes of mirex from fish consumption ranged from 0.13 µg/day to 0.39 µg/day. These intakes are low however, if the upper value were considered this may comprise up to 10% of the recommended oral TRV. Mirex use in Australia in the past decade was limited (only in the NT) prior to final phase-out in 2007. Hence, background intakes in Australia are expected to be less than reported in the US. It is therefore reasonable to consider background intakes as essentially negligible.

9.4              Identification of Toxicity Reference Values

9.4.1         Classification
The International Agency for Research on Cancer (IARC 1987) has classified mirex as Group 2B—possibly carcinogenic to humans.

It is noted, that the current information from US EPA (IRIS 2012) notes that US EPA has not classified mirex. A draft review of mirex (US EPA 2003) identified mirex as likely to be carcinogenic to humans based on consistent findings of hepatic carcinogenic responses and less consistent findings of tumours in other tissues in several dietary studies in rats and mice. The human relevance of the animal evidence of carcinogenicity is assumed in the absence of adequate human data or mechanistic data to indicate that the mode of carcinogenic action in animals is not relevant to humans.

9.4.2         Review of Available Values/Information
There is some evidence that mirex is carcinogenic, based on studies in experimental rats and mice (WHO 1984). More recent review of mirex by US EPA (2003) indicates that the mechanism by which mirex causes non-neoplastic and neoplastic lesions in the liver is poorly understood. Mirex has not been genotoxic in numerous short-term in vitro and a few in vivo tests (also noted by WHO 1984), leading to the hypothesis that tumorigenic responses to mirex in