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Environmental fate & pathways

Distribution modelling

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Administrative data

Endpoint:
distribution modelling
Type of information:
other: Modelling
Adequacy of study:
key study
Study period:
1985
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Data from peer-reviewed handbook or collection of data; comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1985
Report Date:
1985

Materials and methods

Model:
other: Leaching according to US Environmental Protection Agency's LEACH method, J. D. Dean, P. P, Jowise. A. S. Donigian, Leaching Evaluation of Agricultural Chemicals (LEACH) Handbook, EPA-600/3-84-068, June 1984.
Calculation programme:
J. D. Dean, P. P, Jowise. A. S. Donigian, Leaching Evaluation of Agricultural Chemicals (LEACH) Handbook, EPA-600/3-84-068, June 1984,
Release year:
1 984
Media:
water - soil

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: particulates

Study design

Environmental properties:
LEACH method is based on
- selection of a crop,
- selection of a location
- selection of a herbicide
- followed by calculation of a retardation factor R and a decay rate, Ks,
- followed by selection of a curve number from the Handbook and, using the factors, locate the appropriate tables to obtain a frequency distribution or percent of years that a fraction of the applied substance, may leach beyond the root growing zone of the crop.

Results and discussion

Percent distribution in media

Water (%):
0.001
Other distribution results:
The Koc of (2-Ethoxy-1-methyl-2-oxoethyl)-5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-nitrobenzoate is in the range of 10000 to 100000 as calculated from water solubility (0.1 mg/L) and absorption in soil recalculated to solubility in the organic matter fraction of the soil.

Any other information on results incl. tables

Independent from the soil and the conditions assumed for assessment, (2-Ethoxy-1-methyl-2-oxoethyl)-5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-nitrobenzoate is not predicted to leach beyond the soybean root zone when used as a soybean herbicide at a maximum rate of 0.2 kg/ha. The leaching potential of lactyl-5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-nitrobenzoate is predicted to be higher. The substance is not predicted to pass below the root growing zone every year, but 9% of the available test substance, 0.0041 kg/ha, may leach below the root growing zone in South Carolina in 10 % of the years. 5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-nitrobenzoic acid is still more likely to leach. Every year in the four soybean growing areas of the US evaluated, leachable levels of PPG-847 may range from nil in Iowa to 6% (0.0027 kg/ha) in South Carolina. The range of 10% predicted excedence would be 5% (0.0023 kg/ha) in Iowa to 60% (0.027 kg/ha) in South Carolina.

Applicant's summary and conclusion

Conclusions:
(2-Ethoxy-1-methyl-2-oxoethyl)-5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-nitrobenzoate is not predicted to be leached beyond the root growth zone
Executive summary:

Leaching of (2-Ethoxy-1-methyl-2-oxoethyl)-5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-nitrobenzoate and its degradation products was modelled using the LEACH method of the US Environmental Protection Agency.

Independent on the soil and the conditions of assumed for assessment, (2-Ethoxy-1-methyl-2-oxoethyl)-5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-nitrobenzoate is not predicted to leach beyond the soybean root zone when used as a soybean herbicide at a maximum rate of 0.2 kg/ha. The leaching potential of lactyl-5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-nitrobenzoate is predicted to be higher. The substance is not predicted to pass below the root growing zone every year, but 9% of the available test substance, 0.0041 kg/ha, may leach below the root growing zone in South Carolina in 10 % of the years. 5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-nitrobenzoic acid is still more likely to leach. Every year in the four soybean growing areas of the US evaluated, leachable levels of the substance may range from nil in Iowa to 6% (0.0027 kg/ha) in South Carolina. The range of 10% predicted exceedence would be 5% (0.0023 kg/ha) in Iowa to 60% (0.027 kg/ha) in South Carolina.