Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:5:p2
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 5 (pt 2/5)
Character Range: 2638935–2642022

post-emergence on triazine-tolerant canola grown on raised beds.

After consideration of the additional assessments completed after 1997, APVMA accepts the recommendations of OCS and the 2004 recommendations of DEWHA, and the following regulatory actions have been applied:
    1. Active constituent approvals have been affirmed.

    2. Existing label instructions have been deemed to be inadequate and the most recently approved labels have been amended as follows:

       * Labels have been amended to specify additional restraints to further reduce the risk of contamination of waterways.

       * Withholding period instructions have been amended.

       * Herbicide resistance reporting details have been added to labels.

These variations to label instructions satisfy the requirements for continued registration of products; and so
    3.                   Product registrations have been affirmed.

    4.                   To ensure that all labels are in line with the recommendations of the 2008 report, any previously approved labels that do not contain the amended instructions have been cancelled.

As an associated outcome of the review, changes will be made to the MRL Standard to align entries in the standard with existing approved use patterns.

5.2              Previous HIL
No previous HIL is available for atrazine (NEPC 1999).

5.3              Significance of Exposure Pathways

5.3.1         Oral Bioavailability
Insufficient data is available to adequately define the bioavailability of atrazine hence a default approach of assuming 100% oral bioavailability has been adopted in the derivation of an HIL. It is noted that a site-specific assessment of bioavailability can be undertaken where required.

5.3.2         Dermal absorption
Insufficient data is available on the dermal absorption of atrazine from soil. Hence the default value of 0.1 (10%) suggested by US EPA (1995) for pesticides has been adopted in the derivation of HILs.

5.3.3         Inhalation of Dust
Atrazine is not considered sufficiently volatile to be of significance and inhalation exposures associated with particulates outdoors and indoors are expected to be of less significance than ingestion of soil. While likely to be negligible, potential inhalation exposures associated with dust have been considered in the HIL derived.

5.3.4         Plant Uptake
Atrazine is used as a herbicide and, as such, is phytotoxic to almost all broadleaf weeds and plants. Some plants are more sensitive than others to residues of atrazine in the soil, however in general, phytotoxicity will occur well before plant uptake into edible portions of fruit and vegetable crops is of significance. Hence the uptake of these compounds into home-grown produce has not been considered in the derivation of an HIL A.

Note that the persistence of 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