Document ID: EPA-HQ-OPP-2009-0575-0002
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2009-09-08T04:00Z

EPA REGISTRATION DIVISION COMPANY NOTICE OF FILING FOR PESTICIDE PETITIONS PUBLISHED IN THE FEDERAL REGISTER 

EPA Registration Division contact: Joanne I. Miller 703-305-6224

INSTRUCTIONS:  Please utilize this outline in preparing the pesticide petition.  In cases where the outline element does not apply, please insert "NA-Remove" and maintain the outline. Please do not change the margins, font, or format in your pesticide petition. Simply replace the instructions that appear in green, i.e., "[insert company name]," with the information specific to your action.

TEMPLATE:

Syngenta Crop Protection, Inc.

[Insert petition number]

	EPA has received a pesticide petition ([insert petition number]) from Syngenta Crop Protection, Inc., PO Box 18300, Greensboro, NC 27419-8300 proposing, pursuant to section 408(d) of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(d), to amend 40 CFR part 180.

(Options (pick one)
   
   	by establishing a tolerance for residues of sodium salt of fomesafen, 5-[2-cloro-4-(trifluoromethyl)phenoxy]-N-(methylsulfonyl)-2-nitrobenzamide in or on the raw agricultural commodities potato at 0.025 parts per million (ppm) and tomato at 0.025 parts per million.  EPA has determined that the petition contains data or information regarding the elements set forth in section 408 (d)(2) of FDDCA; however, EPA has not fully evaluated the sufficiency of the submitted data at this time or whether the data supports granting of the petition. Additional data may be needed before EPA rules on the petition.

A. Residue Chemistry

	1. Plant metabolism. Cotton, soybean and tomato metabolism studies were conducted using 14C-labeled fomesafen. The major degradation pathway of fomesafen in these commodities involves biphenyl ether cleavage facilitated by homoglutathione conjugation. The major portion of the applied chemical is comprised of ring cleavage products and their conjugates.  Residues of parent fomesafen are low, <0.012 ppm. Very little translocation from treated foliage or soil to raw agricultural commodities occurs. The nature of the residue is adequately understood

	2. Analytical method. The analytical method used for analysis of the potato tubers, tomato fruit and related processed fractions was based upon methodology previously utilized for analysis of fomesafen in soybeans.  

	3. Magnitude of residues. Potato and Tomato. The magnitude of the residue studies are submitted with this petition for potato and tomato.  These studies were conducted per EPA Test Guidelines 860.1000, 860.1500, and 860.1520.    

B. Toxicological Profile
The United States Environmental Protection Agency (EPA) has evaluated the available fomesafen toxicological database and considered its validity, completeness, and reliability as well as the relationship of the results of the studies to human risk. EPA has also considered available information concerning the reliability of the sensitivities of major identifiable subgroups of consumers, including infants and children. The nature of the toxicity profile of fomesafen is discussed in the May 3, 2006 Federal Register publication of the Final Rule for establishing tolerances for residues of fomesafen in or on dry bean, snap bean and cotton [EPA-HQ-OPP-2006-0073; FRL-8062-6]. 

C. Aggregate Exposure

	1. Dietary exposure. A Tier I chronic dietary exposure evaluation was made for fomesafen using the Dietary Exposure Evaluation Model (DEEM-FCIDTM, version 2.16) from Exponent. These exposure assessments included fomesafen use on soybeans, dry beans, succulent beans, cotton gin byproducts, cotton undelinted seed and proposed new uses on potatoes and tomatoes. Tolerance values were used for raw agricultural commodities. There are no expected dietary exposures as a result of residues of fomesafen in meat, milk, poultry or eggs based on low levels of residues in feedstuff and low transfer factors as determined from the goat and hen metabolism studies. Drinking water estimates were incorporated directly into the dietary exposure assessment using the higher of the estimated drinking water concentrations (EDWCs) for surface and ground water.

	i. Food. Acute Exposure. Fomesafen is not considered to be acutely toxic. No studies that would suggest an appropriate reference dose for acute exposures are present in the available toxicological studies for fomesafen.

Chronic Exposure. The fomesafen chronic dietary risk assessment was performed for all population subgroups with a chronic reference dose of 0.0025 mg/kg-bw/day based on a chronic toxicity study in rats with a no observed adverse effect level (NOAEL) of 0.25 mg/kg-bw/day and an uncertainty factor of 100X. The 100X safety factor includes intra- and inter-species variations. No additional FQPA safety factor was applied. For the purpose of aggregate risk assessment, the exposure values were expressed in terms of margin of exposure (MOE), which was calculated by dividing the NOAEL by the exposure for each population subgroup. In addition, exposure was expressed as a percent of the reference dose (%RfD). Chronic dietary (food only) exposure to the U.S. population resulted in a MOE of 2,377 (4.2% of the chronic RfD of 0.0025 mg/kg-bw/day). The most exposed sub-population was children (1-2 years old) with a MOE of 983 (10.2% of the chronic RfD). 

Cancer. Fomesafen has been classified as not likely to be carcinogenic in humans. Therefore, no cancer risk assessment was performed for fomesafen.

	ii. Drinking water. The Estimated Drinking Water Concentrations (EDWCs) of fomesafen were determined for groundwater using results from a 3-year prospective groundwater (PGW) study and for surface water using the Tier II PRZM/EXAMS model which estimates pesticide concentrations in surface water. EDWCs of fomesafen from the currently registered uses plus the proposed uses on potatoes and tomatoes were determined. Based on the PGW study results, the groundwater EDWC for fomesafen was 1 ppb (chronic). Using Tier II modeling for surface water, the currently registered dry beans use based on a single pre-emergence aerial application rate at 0.375 lb/A, provided the highest chronic EDWC of 3.890 ppb (adjusted for 0.87 Percent Cropped Area, PCA). Since the surface water chronic EDWC exceeds the ground water EDWC, the surface water value was used for risk assessment purposes and will be considered protective for any ground water concentration concerns.

Chronic Exposure from Drinking Water: The chronic EDWC of 3.890 ppb (0.00389 ppm) was input directly into the DEEM-FCID(TM) software as "water, direct and indirect, all sources" to model the chronic drinking water exposure. Chronic drinking water exposure to the U.S. population resulted in a MOE of 3,049 (3.3% of the cRfD of 0.0025 mg/kg-bw/day). The most sensitive sub-population was all infants (<1 year old), with a MOE of 930 (10.8% of the cRfD of 0.0025 mg/kg-bw/day). Since the Benchmark MOE for this assessment was 100 and since the EPA generally has no concern for exposures below 100% of the cRfD, Syngenta believes that there is a reasonable certainty that no harm will result from chronic drinking water exposure to residues arising from all current and proposed uses of fomesafen.

	2. Non-dietary exposure. There are no current or proposed uses of fomesafen that would result in residential exposure.

D. Cumulative Effects

	Cumulative Exposure to Substances with a Common Mechanism of Toxicity. Section 408(b)(2)(D)(v) requires that, when considering whether to establish, modify, or revoke a tolerance, the Agency consider "available information" concerning the cumulative effects of a particular pesticide's residues and "other substances that have a common mechanism of toxicity". The EPA does not have, at this time, available data to determine whether fomesafen has a common mechanism of toxicity with other substances or how to include this pesticide in a cumulative risk assessment. For the purposes of this tolerance action, the EPA has not assumed that fomesafen has a common mechanism of toxicity with other substances.

E. Safety Determination

	1. U.S. population. The chronic dietary exposure analysis (food plus water) showed that exposure from all established and proposed uses of fomesafen would result in a MOE of 1,336 (7.5% of the chronic RfD) for the general U.S. population. Based on the completeness and reliability of the toxicity data supporting these petitions, Syngenta believes that there is a reasonable certainty that no harm will result from aggregate exposure to residues arising from all current and proposed fomesafen uses, including anticipated dietary exposure from food, water, and all other types of non-occupational exposures.

	2. Infants and children. Using the conservative assumptions described in the exposure section above, and based on the completeness and reliability of the toxicity data, the chronic aggregate exposure calculation for current and proposed uses of fomesafen provided a MOE of 622 for infants <1 year old (the most sensitive population subgroup). Since the aggregate MOE of 622 (16.1% of the chronic RfD) exceeds the benchmark MOE of 100, Syngenta believes that there is a reasonable certainty that no harm will occur to infants and children from aggregate exposure to residues arising from all current and proposed fomesafen uses, including anticipated dietary exposure from food, water and all other types of non-occupational exposures.

F. International Tolerances

	There are no Codex maximum residue levels (MRLs) established for residues of fomesafen in or on soybeans, cotton, dry beans or snap beans. A Canadian tolerance of 0.05 ppm is established for fomesafen residues in or on soybeans, dry beans, lima beans, snap beans. A Mexican tolerance of 0.01 ppm is established for fomesafen residues in or on `beans'.