Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:7:p3
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 7 (pt 3/4)
Character Range: 2672208–2675636

establishing an HIL, intakes from other sources has been taken to be 10% of the adopted TRV.

7.4              Identification of Toxicity Reference Values

7.4.1         Classification
The International Agency for Research on Cancer (IARC) and US EPA have not classified bifenthrin as to carcinogenicity. It is noted that the Joint Meeting on Pesticide Residues (JMPR 1993) has reviewed bifenthrin, which was evaluated as unlikely to pose a carcinogenic hazard to humans.

7.4.2         Review of Available Values/Information
A summary of health effects and information is presented by Taylor & Di Marco (2003). Limited data is available for the assessment of carcinogenicity, though the available data suggests that bifenthrin was not likely to pose a carcinogenic risk to humans.

On the basis of the available information it is considered appropriate that a threshold doseresponse approach be adopted for bifenthrin. The following are available from Level 1 Australian and International sources:
Source              Value                    Basis/Comments
Australian
ADWG                No evaluation available
OCS (2012)          ADI = 0.01 mg/kg/day     The ADI of 0.01 mg/kg/day based on maternal tremors in a developmental rat study. The value was set in 1992. The ADI is also used by FSANZ (2003).
International
JMPR (1993)         ADI of 00.02 mg/kg/day  ADI established on the basis of a NOAEL of 1.5 mg/kg/day in a 1-year study in dogs, and a 100-fold uncertainty factor. The study was supported by the same NOAEL in the rat teratology study. ADI presented has been rounded by JMPR.
WHO                 No evaluation available
RIVM (2001)         No evaluation available
ATSDR               No evaluation available
US EPA (IRIS 2012)  RfD = 0.015 mg/kg/day    US EPA has established an oral RfD of 0.015 mg/kg/day based on a NOEL of 1.5 mg/kg/day associated with tremors in a 1-year dog study, and 100-fold uncertainty factor.

Based on the available data, the current Australian ADI of 0.01 mg/kg/day is considered current and relevant.

No dermal or inhalation-specific studies or data are available. For the presence of bifenthrin in soil (not during use), it is considered appropriate to consider use of the available threshold reference value for all pathways of exposures.

7.4.3         Recommendation
On the basis of the discussion above, the following toxicity reference values (TRVs) have been adopted for bifenthrin in the derivation of HILs:

7.5              Calculated HILs
On the basis of the above, the following HILs have been derived for bifenthrin (refer to Appendix B for equations used to calculate the HILs and Appendix C for calculations):
HIL Scenario            HIL (mg/kg)                      Percentage Contribution from Exposure Pathways
Ingestion of Soil/Dust  Ingestion of Home-grown Produce  Dermal Absorption of Soil/Dust                  Inhalation (dust)
Residential A           600                              43                                              --                 57  <1
Residential B           840                              16                                              --                 84  <1
Recreational C          730                              27                                              --                 73  <1
Commercial D            4500                             12                                              --                 88  <1