U.S. Sets Difenoconazole Residue Tolerances

WASHINGTON - Sep 13/06 - SNS -- The United States's Environmental Protection Agency (EPA) is establishing maximum tolerance levels for residues of difenoconazole following a request by Syngenta Crop Protection, Inc.

The tolerances will apply when it is used as a seed treatment in or on barley, hay; barley, straw; corn, sweet, forage; corn, sweet, kernel plus cob with husks removed; corn, sweet, stover; cotton, gin byproducts; cotton, undelinted seed; and as a foliar treatment on fruit, pome, group 11 (import); and on grape (import).

In developing its tolerances, the EPA noted, "There are currently no established Codex, Canadian, or Mexican maximum residue limits (MRLs) for difenoconazole. Therefore, no conflict exists between any of the existing and proposed U.S. difenoconazole tolerances and any difenoconazole MRL."

Tolerances in or on barley, hay aer set at 0.05 ppm (parts per million); barley, straw at 0.05 ppm; corn, sweet, forage at 0.01 ppm; corn, sweet, kernel plus cob with husks removed at 0.01 ppm; corn, sweet, stover at 0.01 ppm; cotton, gin byproducts at 0.05 ppm; cotton, undelinted seed at 0.05 ppm; and as a foliar treatment on fruit, pome, group 11 at 0.10 ppm; and on grape at 0.10 ppm.

This rule also changes the chemical name of the active ingredient, difenoconazole, from (2S,4R)/(2R/4S)]/[(2R/4R)]/(2S,4S) 1-(2-[4-(4-chlorophenoxy)-2-chlorophenyl]-4-methyl-1,3-dioxolan-2-yl-methyl)-1H-1,2,4-triazole, to the following, (1-[2-[2-chloro-4-(4-chlorophenoxy)phenyl]-4-methyl-1,3-dioxolan-2-ylmethyl]-1H-1,2,4-triazole).

The EPA said the change in the chemical name of the active ingredient is necessary to conform to the nomenclature of the Chemical Abstracts Service, the body which the Office of Pesticide Programs regards as authoritative for issues of chemical nomenclature. This name change makes no substantive change to either the chemical identity of difenoconazole or to the effect of the tolerances.

EPA is not establishing the requested tolerance of 0.05 ppm on barley, forage, because a tolerance is no longer required for this commodity. EPA is also deleting several established tolerances in Sec.180.475 (b) that are no longer needed, as a result of this action: 0.1 ppm on corn, sweet, kernel plus cob with husks removed with a 12/31/08 expiration date; 0.1 ppm on corn, sweet, forage with a 12/31/08 expiration data; and 0.1 ppm on corn, sweet, stover with a 12/31/08 expiration date.