Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:5:p3
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 5 (pt 3/5)
Character Range: 2641765–2644804

atrazine in soil and potential for phytotoxic effects may need to be addressed on a site-specific basis if detected in soil.

5.3.5         Intakes from Other Sources – Background
Reviews of potential intakes from sources other than soil (primarily food) by NRA (1997), NHMRC (2011) and RIVM (2001) suggested these intakes were essentially negligible. Further review of residue data by APVMA (2008) noted that, when atrazine was used in accordance with the revised label directions, residues were unlikely to pose a risk to human health. Potential exposures during application of atrazine products may require further consideration on a site-specific basis; however exposures by the general public (in areas away from application) are negligible.

5.4              Identification of Toxicity Reference Values

5.4.1         Classification
The International Agency for Research on Cancer (IARC 1999) has classified atrazine as Group 3—not classifiable. US EPA has not classified atrazine.

5.4.2         Review of Available Values/Information
The available data reviewed by JMPR (2007) and APVMA (2008) suggested that atrazine was not likely to pose a carcinogenic risk to humans. Review by JMPR (2007) and RIVM (2001) suggested that based on the weight of evidence, atrazine was not genotoxic. There is some evidence that it can induce mammary tumours in rats as a result of hormonal changes, but the mechanism is believed to be non-genotoxic. On the basis of the available information, it is considered appropriate that a threshold doseresponse approach be adopted for atrazine.

The following are available from Level 1 Australian and International sources:
Source              Value                    Basis/Comments
Australian
ADWG (NHMRC 2011)   ADI = 0.005 mg/kg/day    Current ADWG (NHMRC 11) of 0.04 mg/L based on 50% intake from drinking water and an ADI of 0.005 mg/kg/day as referenced from the TGA (NRA 1997).
OCS (2012)          ADI = 0.005 mg/kg/day    The ADI of 0.005 mg/kg/day is noted to be based on a NOEL of 10ppm associated with mammary tumours from a 24-month female rat study, and a 100-fold safety factor. This value was set in December 1996.
NRA (1997)          ADI = 0.005 mg/kg/day    The NRA (1997) review identified the relevance of adopting an ADI of 0.005 mg/kg/day for atrazine. This value has been reconfirmed in the update provided by APVMA (2008). However the review noted that APVMA has initiated a project to re-examine the possibility that the triazines may have harmful endocrine effects, including updates available from JMPR. APVMA also note that US EPA is currently reviewing atrazine.
International
JMPR (2007)         ADI = 0.02 mg/kg/day     Review of atrazines by the Joint FAO/WHO Meeting on Pesticides Residues (JPMR, 2007) identified a group ADI (for atrazine, diethyl-atrazine, di-isopropyl-atrazine and diaminochlorotriazine) of 00.02 mg/kg/day based on oestrous cycle disruption.
WHO (2011)          ADI = 0.02 mg/kg/day     Group ADI for atrazine and its chloro-s-triazine metabolites