UNITED STA TES ENVIRONMENTA L PROTECTION AGENCY

MEMORANDUM Date: February 22 , 2011 SUBJECT: Mefenp yr - d ieth yl (Safener HOE 107892)

Sorghum and Grass Grown for Seed. and Residue Data. PC Code: 811800 (multiple actives 035302, 128920, 000692) Decision No.: 425581 Petition No.: 9F7679 (related to 9F7678 and 9F7680) Risk Assessment Type: NA T XR No.: None MRID No.: 47815001, 47815002 FROM: Alexandra LaMay, Biologist

Toiya Goodlow, Chemist Risk Assessment Branch VII Health Effects Division (7509P) THROUGH: Christine Olinger , Chemist

Michael S. Metzger, Branch Chief Risk Assessment Branch VII Health Effects Division (7509P) TO: Bethany Benbow

Herbicide Branch Registration Division (7505P) Executive Summary Mefenp yr - dieth yl( AE F107892, Safeners are substances added to herbicidal active ingredients in formulations to protect crops from potential adverse effects of the herbicides. Although safeners are not considered to be pesticidal by

the Agency , they

are often similar in molecular stru the Agency

has established some tolerances for safeners including Page 1 of 20 UNITED STA

TES ENVIRONMENTA L PROTECTION AGENCY WASHINGTON, D.C. 20460 OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

(Safener HOE 107892) . Petition for Section 3 Registration of Sorghum and Grass Grown for Seed. Revised Summary of Anal yt ical Chemistry 811800 (multiple actives 035302, DP Barcode: 380768 Registration No. : NA (related to 9F7678 and Regulatory Action: Section 3 Registration Case No.: NA CAS No.: 135590 - 91 - 9 47815001, 47815002 40 CFR: 180.509

LaMay, Biologist Toiya Goodlow, Chemist Risk Assessment Branch VII Health Effects Division (7509P)

, Chemist Michael S. Metzger, Branch Chief Risk Assessment Branch VII

Division (7509P) Herbicide Branch Registration Division (7505P) AE F107892, HOE 107892) is a safener used with several herbicides. Safeners are substances added to herbicidal active ingredients in formulations to protect crops from potential adverse effects of the herbicides. Although safeners are not considered to be pesticidal by

the Agency , they

are often similar in molecular stru cture to active pesticides. the Agency

has established some tolerances for safeners including mefenpyr - dieth yl UNITED STA

TES ENVIRONMENTA L PROTECTION AGENCY OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

Registration of Summary of Anal yt ical Chemistry

Section 3 Registration

HOE 107892) is a safener used with several herbicides. Safeners are substances added to herbicidal active ingredients in formulations to protect crops from potential adverse effects of the herbicides. Although safeners are not considered to be cture to active pesticides. Thus,

dieth yl .Mefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 2 of 20 Baye r CropScience has requested new uses of mefenp yr - diethyl on sorghum and grass grown for seed (PP #9F7679). Huskie herbicide is an emulsifiable concentrate which also contains active ingredients (ais) bromoxy nil and p yr asulfotole ; related petitions 9F7678 and 9F7680 were submitted to support the establishment of tolerances for these ais . In conjunction with the new uses on sorghum and grass grown for seed , the petitioner is proposing the establishment of permanent tolerances for residues of the herbicide safener mefenpy r - diethyl (1 - (2,4 - dichlo rophen yl ) - 4,5 - dihydro - 5 - methyl - 1H - py razole - 3,5 - dicarboxylic acid, dichlorophen yl py razoline metabolites at a rate of 0.053 pound safener per acre in/on the following commodities: Grass, forage ................................ ................................ 1.5 ppm

Grass, hay ................................ ................................ ... 0.05 ppm Sorghum, forage ................................ ........................... 0.1 ppm Sorghum , grain ................................ .......................... 0.01 ppm Sorghum, stover ................................ ........................ 0.05 ppm The metabolism of mefenpy r - diethyl in plants (barley) and anima ls (goat, rat, and hen) is well understood. I dentified metabolic pathway s are substantially s imilar in plants and animals. E PA has determined th at mefenp yr - diethyl parent and its three 2,4 - dichlorophen yl - py razoline metabolites : AE F113225, AE F109453, and AE F094270 ( also known as HOE 113225, HOE 109453, and HOE 094270) are the residues of concern for risk assessment and tolerance setting purposes . An enforcement method for plants entitled “An Analy tical Method for Determination of Residues of AE F107892 (mefenp yr - diethyl) and its Metabolites in Wheat and Barley by Gas Chromatograph y using Mass Selective Detection (Report Supplement to EPA MRID 45 457401)” is available. Radiovalidation and independent laboratory validation (ILV) data have been submitted for the plant method. The Agency determined that this method is suitable for crop tolerance enforcement of mefenp yr - diethyl and the three metabolites AE F 094270, A E F113225, and/or A E F 109453. In the data - colle ction method used in the grass and sorghum field trial studies , the residues of mefenp yr - diethyl and its metabolites AE F113 225, AE F109453, and AE F094270 were quantitated by

high pressure liquid chromatography with electrospray

ionization /tandem mass spectrometry

(LC - MS/MS). The lower limit of method validation (LLMV) for each analy te was 0.10 ppm in sorghum and grass forage , 0.01 ppm in sorghum grain, and 0.05 ppm in sorghum stover and grass hay . The method is acceptable based on concurrent recoveries. Multiresidue method testing data are available for mefenp yr - diethyl and its metabolites. Mefenp yr - diethyl and its metabolites have been screened through FDA Multiresidue Method Protocols A, B, C, D, E and F. Mefenp yr - diethyl and AE F094270 were recovered through protocol C and partiall y recovered through protocol D. AE F113225 and AE F109453 were not recovered through an y of the protocols tested. No additional multiresidue testing is required. Adequate confined rotational crop data for mefenpy r - diethyl are available . [Phenyl 14 C] HOE 107892 (mefenp yr - diethyl parent) was applied to soil at a rate significantly higher than theMefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 3 of 20 proposed use rate. Spinach, carrot, and wheat were planted back at 29 day s and 1 year. Based on the results of the residue uptakes, HED recommended a 30 - day plant - back interval (PBI) for leafy , fruiting, and root vegetables, and 12 - month PBI for all other crops other than wheat and barley , which can be replanted at an y time. There are livestock feedstuffs associated with the proposed cro p tolerances. These feedstuffs include grass forage, grass hay , sorghum forage, sorghum grain and sorghum stover. While the addition of this grass forage livestock feed item has increased the dairy cattle livestock dietary burden slightl y, a review of th e available metabolism studies indicates that no new or increased livestock tolerances are needed to support this action. However, the petitioner is advised that any proposed future amendments which impact residues in feed items or any new uses on new fe ed items may

trigger the need for animal feeding studies . Analy tical standards for mefenpy r - diethyl, mefenpy

r dimeth ylmetabolite, mefenpy r ethyl methyl, and mefenpy

r monoethyl (AEF113225) are currentl y available in the EPA National Pesticide Standards Repository . The anal yt ical standards for mefenp yr impurity and metabolite of mefenp yr diethyl have expired; the registrant must ensure that anal yt ical standards are available for the parent chemical and all metabolites. No Codex, Canadian, or Mexican max imum residue limits (MRL s) are established for residues of mefenp yr - diethyl and metabolites in crop or livestock commodities; therefore, there are no issues with international harmonization raised by this action. Regulatory Recommendations and Residue C hemistry Deficiencies Provided RD assures that the petitioner submits a revised Section F as noted below , there are no residue chemistry

issues that would preclude granting a registration for use of mefenp yr - die thyl as a safener in/on grass grown for seed and sorghum. The proposed uses and the submitted data support the following tolerances for residues of the herbicide safener mefenpy r - diethyl (1 - (2,4 - dichlorophenyl) - 4,5 - dihydro - 5 - methyl - 1H - py razole 3,5 - dicarbox yl ic acid , diethyl ester) and its 2,4 - dic hlorophen yl - py razoline metabolites in/on the following crop commodities:

Grass, forage ................................ ................................ 1.6 ppm Grass, hay ................................ ................................ ..... 0.2 ppm Sorghum, forage ................................ ........................... 0.4 ppm Sorghum, grain ................................ .......................... 0.04 ppm Sorghum, stover ................................ .......................... 0.2 ppm Note to RD: The tolerance expression should be changed as described below: Tolerances are established for residues of the safener me fenpy r - diethyl, including its metabolites and degradates, in or on the commodities in the table below. Compliance with the tolerance levels specified below is to be determined by measuring only

the sum of mefenpy

r - diethyl (1 - (2,4 - dichlorophen yl ) - 4,5 - dihydro 5 - methyl - 1H - py

razole - 3,5 - dicarbox yl ic acid , diethyl ester) and its 2,4 - dichlorophen yl - py

razoline metabolites, calculated as the sto ichiometric equivalentMefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 4 of 20 of mefenp yr - diethyl, in or on the commodity . 860.1480 L ivestock Feeding Study The petitioner is advised that any proposed future amendments which impact residues in feed items or any

new uses on new feed items may trigger the need for animal feeding studies. The livestock feeding study s hould include validation data for the parent compound and all metabolites. 860.1550 Proposed Tolerances The petitioner is required to submit a revised Section F to correct the tolerance expression to be consistent with the guidance issued 5/27/10 (S. Knizner) as well as the correct commodity definition for the requested crops (presented in Table 8 ). The tolerance expression should be changed as described below: Tolerances are established for resi d ues of the safener me fenpy r - diethyl, including its metabolites and degradates, in or on the commodities in the table below. Compliance with the tolerance levels specified below is to be determined by measuring only

the sum of mefenpy

r - diethyl (1 - (2,4 - dich lorophen yl ) - 4,5 - dihydro 5 - methyl - 1H - py

razole - 3,5 - dicarbox yl ic acid , diethyl ester) and its 2,4 - dichlorophen yl - py

razoline metabolites, calculated as the stoichiometric equivalent of mefenp yr - diethyl, in or on the commodity . In addition, the tolerances for canola seed, so yb ean seed, so ybean forage, and soybean hay should be moved from section (a) to section (d). The introductory paragraph in section (d) should read as follows: Tolerances for are established for the indirect or inadvertent residues of mefenpy r - diethyl, including its metabolites and degradates, in or on the commodities identified in the table below. Compliance with the tolerance levels specified below is to be determined b y measuring only the sum of mefenp yr diethyl (1 - (2,4 - dichlorophenyl) - 4 ,5 - dihydro - 5 - methyl - 1H - py razole - 3,5 - dicarbox yl ic acid , diethyl ester) and its 2,4 - dichlorophenyl - py razoline metabolites, calculated as the stoichiometric equivalent of mefenp yr - diethyl, in or on the commodity . A human health risk assessment is forthcoming in a separate document. Background Mefenp yr - diethyl is an herbicide safener used in combination with several herbicides developed by Bayer CropScience for agricultural use on cereal grains. The nomenclature of mefenpy r diethyl is summarized in Table 1, and the ph ys icochemical properties are summarized in Table 2.Mefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 5 of 20 Table 1. Mefenpyr - Diethyl Nom enclature . Chemical structure

Common name Mefenpyr - diethyl Com pany experimental name AE F107892, HOE 107892 IUPAC name (RS ) - 1 - (2 - ,4 - dichlorophenyl) - 5 - methyl - 2 - py razoline - 3,5 - dicarboxylic acid CAS name 1 - (2,4 - dichlorophenyl) - 4,5 - dihydro - 5 - me thyl - 1 H - pyrazole - 3,5 - dicarboxylic acid, diethyl ester CAS registry number 135590 - 91 - 9 End - use product (EP) PUMA 1EC, Silverado, Rimfire, Osprey, Olympus Flex, AE 0317309 02 SE06 and AE 0317309 03 EC23 Chemical structure of AE F094270 (HOE 094270) metabolite

Chemical structure of AE F109453 (HOE 109453) metabolite

Chemical structure of AE F113225 (HOE 113225) metabolite O O C H 3 O O C H 3 N N Cl Cl

C H 3

N N Cl Cl

C H 3 C O 2 H

N N Cl Cl

C H 3 C O 2 H H O 2 C

N N Cl Cl

C H 3 C O 2 H H 3 C H 2 C O O CMefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 6 of 20 Table 2. Physicochemical Properties of Mefenpyr - Diethyl. Parameter Value Reference Melting point/range 50 - 52 oC 43 - 47 oC MRID 43984109 pH Was not carried out, because mefenpyr diethyl technical is practically insoluble and nondispersible in water. MRID 43984109 Density (20 oC) 1.31 g/cm3 at 20oC MRID 43984109 Water solubility (20 oC) 0.017 g/L at pH 0.9 0.020 g/L at pH 6.2 pH 10 solubility not determined due to compound hydrolysis MRID 43984109 Solvent solubility (20 oC) Methanol >400 g/L isopropanol 151 g/L n - hexane 35 g/L toluene >400 g/L dichloromethane >500 g/L acetone >500 g/L ethyl acetate >400 g/L dimethylsulfoxide >500 g/L polyethylene glycol 151 g/L sesame oil 56 g/L MRID 43984109

Vapor pressure (20 oC) 6.3 x 10 - 6 Pa MRID 44024001 Dissociation constant, pKa Neither acidic nor basic functional groups. Dissociation, if any, is expected to be negligible. MRID 43984109 Octanol/water partition coefficient, Log(KOW ) 3.83 at pH 6.3 and 21 oC MRID 43984109 UV/visible absorption spectrum (nm) Primary λmax = <200 Secondary λmax = 305 MRID 43984109 860.1200 Directions for Use The end - use product relevant to the petition ( PP# 9F7679 ) is HUSKIE TM Herbicide (EPA Reg. No. 264 - 1023), an emulsifiable concentrate ( EC ) formulation containing 3.3% py rasultotole, 13.4% bromox yn il octanoate, and 12.9% bromoxy nil heptanoate as the active ingredients (equivalent to 0.31 lb ae/gal of p yr asulfotole and 1.75 lbs/gal of bromoxy nil). Insupport of the proposed use of HUSKIE TM Herbicide on sorghum and grasses grown for seed, the petitioner submitted a draft label for HUSKIE TM Herbicide. The proposed label states that mefenp yr diethyl is a safener in the Huskie® Herbicide. Mefenpy r - diethyl, also known as Diethyl - 1 - (2,4 - Dichlorophen yl ) - 5 - Methyl - 2 - Py razolin - 3,5 - Dicarbox yl ate or HOE 107892 is a safener currentl y used with several herbicides on cereal grain . Mefenpy r - diethyl is formulated in HUSKIE TM Herbicide (containing 0.08 lbs of mefenp yr - diethyl per gallon) and is proposed at application rates of 0.010 lbs ai/A for sorghum and 0.009 lbs ai/A for grass grown for seed/conservation reserve land. The proposed uses include a maximum of two applications per season for grass grown for seed and sorghum. Mefenp yr - diethyl has current registrations for cereal grains (wheat, barley , oats, rye). The maximum seasonal use rate is 0.053 lb safener/A in registered end - use products. The pre - harvest interval (PHI) for sorghum is 60 day s, and the PHIfor grass hay is 30 days. A summary

of the proposed use directions for sorghum and grasses grown forMefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 7 of 20 seed is presented in Table 3A. Table 3A. Summary of Proposed Use Directions of Huskie ® Herbicide (EPA Reg. No. 264 - 1023 ) Applic. Timing, Type, and Equip. Applic. Rate (lb safener /A) Max. No. Applic. per Season Max.

Seasonal Applic. Rate (lb ae/A) PHI

(days) Use Directions and Limitations Grasses Grown for Seed/ Conservation Reserve Land Broadcast preemergence and postemergence application to annual and perennial grasses grown for seed and conservation reserve program acres (CRP) Ground/Aerial/ Chemigation 0.009 2 0.0 18 30 Apply 13.5

– 15 ounces of HUSKIE TM Herbicide per application per acre. Two applications can be made per ye ar separated by at least 30 days. Do not apply more than 30 ounces of HUSKIE TM Herbicide per acre per year. Grass forage may be cut or grazed any time after application but do not cut for hay within 30 days after treatment. Sorghum

Broadcast postemergence application to actively growing sorghum Ground/Aerial 0. 01 2 0. 0 2 60 Apply 12.8 - 16 ounces of HUSKIE TM Herbicide per acre. Apply the appropriate dosage broadcast in a minimum of 10 or mo re gallons of water per acre. In denser canopies, 15 gallons of water per acre should be used. Two applications of HUSKIE TM Herbicide with a total of 32 ounces may be ap plied per year. A maximum 16 ounces of HUSKIE TM Herbicide per acre per application may be applied. There must be an interval of at least 11 days between treatments. Do not apply through any type of irrigation system. Do not graze or cut for forage 7 days after a HUSKIE TM Herbicide application. Do not harvest for grain or stover within 60 days of a HUSKIE TM Herbicide application. General Use Directions Mefenp yr - diethyl is formulated in HUSKIE TM Herbicide and is proposed at 0.010 lbs ai/A for sorghum, and 0.009 lbs ai/A for grass grown for s eed/conservation reserve land, with a maximum of two applications per season for grass grown for seed and sorghum.Mefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 8 of 20 Spray additives : The draft label specifies that spray additives cleared for use on growing crops under 40 CFR §180.1001 may be used in the spray mixture. A nonionic surfactant (NI S), ammonium nitrogen fertilizer or other adjuvants may be used . Application equipment : Ground applications are to be made in a minimum of 10 gal/A, and aerial applicatio ns are to be made in a minimum of 5 gal/A. HUSKIE TM Herbicide a pplications are not to be made through an y t yp e of irrigation equipment for so r ghum . HUSKIE TM alone or in tank mixture with other products on the label, which are registered for chemigation a pplication, may

be applied to grasses in irrigation water at label - recommended rates. Tank mixtures with other products registered for use on grasses grown for seed and sorghum : The draft label provides mixing procedures for tank mixes and specifies tank mix partners for sorghum and grasses . The use directions state that, for tank mix combinations, the recommendations, restrictions, and limitations for all products must be followed and that the most restrictive labeling is to apply . For application in sorghum , HUSKIE TM may be tank mixed with other pesticide products registered for use in this way and timing in sorghum. For weed control, the proposed label states that HUSKIE TM can be tank mixed with 0.25

– 1.0 pound atrazine per acre, and HUSKIE TM plus atrazine can be tank mixed with phenoxy broadleaf herbicides (such as 2,4 - D or dicamba) as needed. For insect control, the proposed label states that HUSKIE TM Herbicide can be tank mixed with Bay

throid®XLprovided the proper timing for insect and weed control are the same. The label prohibits HUSKIE TM to be tank mixed with L orsban as unacceptable crop response may occur. For applications in annual and perennial grasses grown for seed and conservation reserve program acres (CRP) , H USKIE TM may also be tank mixed with other pesticide products registered for use in this way and timing in grasses . For weed control, the proposed label states that HUSKIE TM can be tank mixed with Puma®, Nortron, Rel y, 2 - 4 - D ester/amine, Aim TM , bromox yn il products (Bronate Advanced TM , Buctril®), Curtail M/Curtail®, Dicamba, Goal, Glean, MCPA ester/ MCPA amine, Sencor®, Starane®/Starane NXT/ Starane Ultra, and WideMatch TM

. For insect control, HUSKIE TM may be tank mixed with Bay

throid®XL, Capture, Lorsban®, Mustang Max TM , or Warrior® insecticides provided that proper timing for insect and weed control are the same. For disease control, HUSKIE TM Herbicide may be tank mixed with Absolute, Tilt®, Quadris®, Quilt TM or Bravo fungicides when timing for application of each tank mix partner is the same. Rotational crop plantback intervals : The draft label specifies that the rotational crops listed in Table 3B may

be planted after applying HUSKIE TM at recommended rates.Mefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 9 of 20 Table 3B. Rotational Crop Plantback Intervals Listed on the HUSKIE TM Herbicide. Crop To Be Planted Minimum Rotation Interval (Day s or Months After Last HUSKIE TM

Application) Wheat, Barley, Oats, Rye and Triticale 1 month Alfalfa 1 , Millet, Sorghum (grain) and Soybeans 4 mo nths Canola, Canaryseed, Chickpeas, Corn, Dry Beans, Flax, Field Peas, Green Beans, Green Peas, Lentils 2 , Mustards, Potatoes, Safflower, Sunflowers, and Sugarbeets 9 mo nths * Do not plant any rotational crop within 30 days following a HUSKIE TM Herbicide application. 1 Thorough tillage prior to planting alfalfa and a minimum of 12 inches of rainfall, overhead, furrow or flood irrigation or any combination of these water sources totaling 12 inches is required between the time following a HUSKIE TM Herbicide application and the time of alfalfa seeding. 2 For Lentils, 9 month minimum rotation interval for all states except 18 months in MN, MT, ND and SD. Conclusions . The available draft label for HUSKIE TM Herbicide is adequate to allow evaluation of residue data relative to the proposed use on grasses grown for seed and sorghum . 860.1300 Nature of the Residue - Plants Residue Chemistry Memo DP#s 238730, 271364, 264319, 276208, 11/22/02, Y. Donovan (PP# 7F04850) T he metabolism of mefenpy r - diethyl in plants (barley) is well understood. Identified metabolic pathway s are substantially similar in plants and animals (goat, rat, and hen). EPA has determined that mefenp yr - diethyl parent and its three 2,4 - dichlorophenyl - py razoline metabolites ( A E F113225, A E F109453, and A E F 094270) are the residues of concern for tolerance setting purposes. 860.1300 Nature of the Residue - Livestock Residue Chemistry Memo DP#s 238730, 271364, 264319, 276208, 11/22/02, Y. Donovan (PP# 7 F04850) Meeting of Metabolism Assessment Review Committee, DP# 263039, 3/27/00, Y. Donovan The qualitative nature of the residue in animals is adequatel y understood based on acceptable studies conducted on goats and laying hens. The metabolic pathway s are the same as those in plants. HED has concluded that the regulated residues in animal comm odities should be the parent compound and those free metabolites A E F113225, A E F109453, and A E F 094270 . 860.1340 Residue Analytical Methods Residue Chemistry Memo DP#s 238730, 271364, 264319, 276208, 11/22/02, Y. Donovan (PP# 7F04850); DERs for MRIDS 47815001 and 47815002, T. Goodlow , 2/22/11 . Plant commodities Enforcement method : In a previous petition (PP#7F04850), the petitioner proposed a GC/MSD method, entitled “An Analy tical Method for Determination of Residues of AE F107892 (mefenp yr - diethyl) and its Metabolites in Wheat and Barley by Gas Chromatograph y using Mass Selective Detection (Report Supplement to EPA MRID 45457401)” for the e nforcement of tolerances for barley

and wheat commodities. Radiovalidation and ILV data have beenMefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 10 of 20 submitted for this method. This method has been forwarded to Agency analy tical lab for petition method validation, and the Agency anal yt ical lab concluded that this method is suitable for food tolerance enfo rcement of mefenp yr - diethyl (AE F 107892) and the three metabolites A E F 094270, A E F113225, and/or A E F 109453. Data - collection method : Samples of sorghum forage, grain, and stover and grass forage and hay were anal yz ed for residues of mefenp yr - diethyl, and its metabolites AE F094270, AE F109453, and AE F113225 using LC - MS/MS Bayer Method 01032, as modified by RAAIP025 Method Modification - 01, and with minor modifications by Py xant Labs Inc. to improve recov ery and chromatograph y. Mefenpyr - diethyl metabolite standards were prepared in individual analy te equivalents and residues were converted to parent equivalents during calculations. Residues of mefenp yr - diethyl and its metabolites AE F094270, AE F113225 and AE F109453 were extracted from homogenous 5.0 - g samples of grass or sorghum with an acetone/water mixture using a blender. After filtration and clean up of the extracts, the solutions were subjected to HPL C - MS/MS analy sis. HPL C separation was performed with a Luna C18(2), 3μm, 150 mm × 2.0 mm HPL C column. The LLMVs were 0.10 ppm in sorghum and grass forage, 0.01 ppm in sorghum grain, and 0.05 ppm in sorghum stover and grass hay . The above method was adequatel y validated b y the petitioner, and is deem ed adequate for data gathering purposes. Animal Commodities No new livestock tolerances are required; therefore a discussion of an enforcement method for those commodities is not relevant to this risk assessment. 860.1360 Multiresidue Methods Residue Chemistry Memo D358191, 11/25/08, D. Davis (PP# 7E7224) Adequate multiresidue method data have been submitted and reviewed b y the Agency . MRID 45447701 entitled Pam I Multiresidue Protocol Testing for Mefenpyr-Diethyl and Metabolites (AE F113225, AE F109453, and AE F094270) provided sufficient data to validate the multiresidue method testing of mefenp yr - diethyl and its metabolites through FDA Multiresidue Method P rotocols A, B, C, D, E and F. Mefenp yr - diethyl and AE F094270 were recovered through protocol C and partially recovered through protocol D. AE F113225 and AE F109453 were not recovered through an y of the protocols tested. No additional multiresidue te sting is required. However, multiresidue method testing appears to have limited use for this safener, as two key metabolites are not detected through any of the tested protocols. The results of the multiresidue testing have been forwarded to the U.S. FDA for further evaluation.Mefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 11 of 20 860.1380 Storage Stability Residue Chemistry Memo DP#s 238730, 271364, 264319, 276208, 11/22/02, Y. Donovan (PP# 7F04850); DERs for MRIDS 47815001 and 47815002, T. Goodlow , 2 /22/11 . No storage stability

data were submitted with the subject petition. Adequate storage stability data are available for residues of mefenpy r - diethyl and its metabolites AE F094270, AE F109453, and AE F113225 in/on barley . Fortified re sidues of mefenp yr - diethyl and its metabolite AE 094270 are stable during frozen storage for up to 30 months in/on barley grain; and fortified residues of mefenp yr - diethyl and its metabolites AE 094270, AE 113225, and AE 109453 are stable during frozen sto rage for up to 30 months in/on barley shoots and straw. The maximum storage interval from sampling to extraction prior to analy sis of mefenp yr - diethyl was 384 day s for grass forage, 372 day s for grass hay , 360 day s for sorghum forage, 303 day s for sorghum grain, and 287 day s for sorghum stover. Available barley storage stability

results were translated to grass and sorghum raw agricultural commodities. The barley storage stability

data adequatel y support the storage durations and conditions of samples from the submitted grass and sorghum field trial studies. The storage durations and conditions of samples from the crop field trials submitted to support this petition are presented in Table 4 . Table 4 . Summary of Storage Conditions for Mefenpyr - diethyl and Metabolites AE F094270, AE F113225, AE F109453 . Matrix Maximum Storage

Tem perature 1 (°C) Actual Maximum

Storage Duration2 (weeks) Interval of Demonstrated Storage Stability 3 Grass forage <0 227 - 384 days (7.3 - 12.4 months) 30 months for me fenpyr - diethyl and AE 094270 in/on barley grain. 30 months for me fenpyr - diethyl, AE 094270, AE 113225, and AE 109453 in/on barley shoots and straw . Grass hay <0 185 - 372 days (6.0 - 12.0 months) Sorghum Forage <0 202 to 360 days (6.5 to 11.6 months) 30 months for me fenpyr - diethyl and AE F094270 in/on barley grain. 30 months for me fenpyr - diethyl, AE F094270, AE F113225, and AE F109453 in/on barley shoots and straw . Sorghum Grain <0 194 to 303 days (6.3 to 9.8 months) Sorghum Stover <0 179 to 287 days (5.8 to 9.3 months) 1 Samples were stored at the field site and analytical laboratory at < 0°C. The storage temperature at BRP between 5/16/2008 and 2/5/2009 was not recorded, however, the freezers were working properly and all samples remained frozen. 2 Storage duration is from date of sampling to date of extraction. Samples were analyzed with in 0 to 2 days of extraction. 3 Refer to DP # 238730, 11/22/02, Y. Donovan 860.1400 Water, Fish, and Irrigated Crops There are no proposed uses that are relevant to this guideline topic. 860.1460 Food Handling There are no proposed uses that are relevant to this guideline topic.Mefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 12 of 20 860.1480 Meat, Milk, Poultry, and Eggs Residue Chemistry Memo DP#s 238730, 271364, 264319, 276208, 11/22/02, Y. Donovan (PP# 7F04850) HED DEEM Memo DP# 286489, 11/22/02, Y. Donovan Tolerances of 0.1 ppm have been established for residues of the herbicide safener mefenp yr diethyl and its 2,4 - dichlorophenyl - py razoline metabolites in meat by products of cattle, goat, hog, horse, and sheep [ 40 CFR §180.509(a)] . There are livestock feed stuffs associated with the proposed crop tolerances. These feedstuffs include grass forage, grass hay , sorghum forage, sorghum grain and sorghum stover. The residues expected in grass forage ruminant feedstuffs increases the dairy cattle livestock dietary burden from 0.57 ppm to 2.9 ppm (Table 5). Based on the tissue/feed ratios estimated from the ruminant metabolism study , the maximum residues expected in liver would be 0.01 ppm and kidney would be 0.04 ppm, which are both below the established toleranc e of 0.1 ppm. The maximum residues estimated for all other edible commodities were below 0.01 ppm, again using the tissue/feed residues from the metabolism study and the maximum reasonable dietary burden. According to the metabolism study , most of the administered dose was eliminated in the urine, indicating considerable absorption and metabolism, and minimal accumulation. Residues in milk collected throughout the study were low and did not increase, supporting the argument that residues are not likely

t o significantl y increase in the feeding study. Revised meat and milk tolerances are not required. The existing meat b y - product tolerances are sufficient, based on the metabolism study , as estimates of kidney and liver residues based on the new dietary burden are still well below 0.1 ppm. Detectable residues in other meat/milk matrices are not expected, and tolerances are not required. Table 5 . Proposed Livestock dietary burdens for Mefenpyr - diethyl (Using revised OPPTS Guidance) Feedstuff Type Tolerance (ppm) % Dry Matter % Diet Dietary Contribution (ppm) Beef Cattle Wheat, straw R 0.5 88 10 0.0568 Untreated R R - - 5 0 Barley, grain CC 0.05 88 50 0.028 Untreated CC CC - - 30 0 Canola, seed PC 0.02 88 5 0.0011 TO TAL 100 0.0859 Dairy Cattle Grass, forage R 1.6 25 45 2.88 Barley, grain CC 0.05 88 45 0.025 Canola, seed PC 0.02 88 10 0.0023 TO TAL 100 2.91 R = roughage, CC = carbohydrate concentrate, PC = protein concentrate 860.1500 Crop Field Trials DERs f or MRIDS 47815001 and 47815002 , T. Goodlow , 2 /22/11 . Baye r CropScience has submitted field trial data for the product HUSKIE TM herbicide on grassMefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 13 of 20 (Bermuda, bluegrass, and fescue). HUSKIE TM herbicide is an emulsifiable concentrate mixture containing p yr asulfotole (37.5 g ai/L), bromoxy nil (210 g ai/L), and mefenpy r - diethyl safener (9.38 g ai/L in formulation). Twelve trials were conducted in the United States and Canada during the 2008 grow ing season. The treatment plots each received two applications of the formulated product at a target rate of 16.1 fl oz HUSKIE TM/A/application, which corresponds to 0.010 lb mefenp yr - diethyl/A/application (0.011 kg mefenpy r - diethyl/ha/application). T otal application rates ranged from 31 to 37 fl oz HUSKIE TM/A/season, with a 27 - to 30 - day re treatment interval (RTI). Grass forage samples were collected at target pre - harvest interval (PHI) of 0 day s and 7 day s. Grass hay samples were collected at a target PHI of 30 day s. A residue decline trial was also conducted at one site. After two applicatio ns of HUSKIE TM Herbicide to grass , t otal mefenp yr - diethyl residues in grass forage ranged from below the LLMV (<0.40 ppm) to 1.59 ppm at a PHI of 0 day s and from below the LLMV to 1.36 ppm at a PHI of 7 to 11 day s. In grass hay samples, residues of mefenp yr - diethyl and its metabolites were all below the LLMV (0.05 ppm each). Residue decline data showed that residues of mef enp yr - diethyl and metabolites decreased with time in grass forage and hay . The results of the grass field trials are summarized in Table 6 below. TABLE 6 . Summary of Grass Residue Data fromCrop Field Trials with Mefenpyr - diethyl. Matrix Total Applic. Rate

(lb a.i./A) (kg a.i./ha) PHI

(days) Residue Levels 1,2 (ppm) n Min. Max. HAFT 3 Median (STMdR) Mean

(STMR) Std. Dev.

4 Me fenpyr - diethyl Grass Forage 0.019 - 0.023

(0.021 - 0.026) 0 24 <0.10 1.09 1.04 0.295 0.351 0.278

7 - 11 24 <0.10 0.931 0.927 <0.10 0.233 0.265 Grass Hay 0.019 - 0.020

(0.021 - 0.023) 28 - 31 24 <0.05 <0.05 <0.05 <0.05 < 0.05 N/A AE F094270 Grass Forage 0.019 - 0.023

(0.021 - 0.026) 0 24 <0.10 <0.10 <0.10 <0.10 <0.10 N/A

7 - 11 24 <0.10 <0.10 <0.10 <0.10 <0.10 N/A Grass Hay 0.019 - 0.020

(0.021 - 0.023) 28 - 31 24 <0.05 <0.05 <0.05 <0.05 <0.05 N/A AE F113225 Grass Forage 0.019 - 0.023

(0.021 - 0.026) 0 24 <0.10 0.33 0.31 <0.10 0.14 0.077

7 - 11 24 <0.10 0.24 0.23 <0.10 0.111 0.036 Grass Hay 0.019 - 0.020

(0.021 - 0.023) 28 - 31 24 <0.05 <0.05 <0.05 <0.05 <0.05 N/A AE F109453 Grass Forage 0.019 - 0.023

(0.021 - 0.026) 0 24 <0.10 <0.10 <0.10 <0.10 <0.10 N/A

7 - 11 24 <0.10 <0.10 <0.10 <0.10 <0.10 N/A Grass Hay 0.019 - 0.020

(0.021 - 0.023) 28 - 31 24 <0.05 <0.05 <0.05 <0.05 <0.05 N/A

Total Mefenpyr - diethyl Residues Grass Forage 0.019 - 0.023

(0.021 - 0.026) 0 24 <0.40 1.59 1.54 0.60 0.69 0.34

7 - 11 24 <0.40 1.36 1.36 0.40 0.54 0.30 Grass Hay 0.019 - 0.020

(0.021 - 0.023) 28 - 31 24 <0.20 <0.20 <0.20 <0.20 <0.20 N/A 1 LLMV = 0.10 ppm in grass forage and 0.05 ppm in grass hay. LOD for mefenpyr - diethyl = 0.0141 ppm for forage and 0.0111 for hay.Mefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 14 of 20 2 Total (ppm) = Sum of mefenpyr - diethyl (ppm), AE F094270 (ppm), AE F113225 (ppm) , and AE F109453 (ppm). LLMV value was used in calculations when values were <LLMV. 3 HAFT = Highest Average Field Trial. 4NA = not applicable because all replicates were <LLMV. Baye r CropScience has submitted field trial data for the product HUSKIE TM herbicide on sorghum grain, forage and stover. Twelve trials were conducted in the United States during the 2008 growing season. The treatment plots each received two applications of the formulated product at a target rate of 16.1 fl oz HUSKIE TM/A/application, which corresponds to 0.010 lb mefenp yr - diethyl/A/application (0.011 kg mefenpy r - diethyl/ha/application). Total application rates ranged from 32 to 33 fl oz HUSKIE TM/A/season. The RTI ranged from 11 to 16 day s. Sorghum forage samples were collected at target PHI of 0 day s and 7 day s and also at earliest commercial harvest (ECH) (BBCH 81, beginning of ripening, to BBCH 87, hard dough), which corresponded to PHIs of 32 to 82 day s. Sorghum grain and stover samples were collected at a target PHI of 60 days. A residue decline trial was also conducted at one site. After two applications of mefenp yr - diethyl to sorghum, the only re sidues that were above the LLMV were mefenp yr - diethyl and AE F113225 in/on sorghum forage at a PHIof 0 day s. M efenp yr - diethyl residues ranged from <LLMV (0.10 ppm) to 1.03 ppm and AE F113225 residues ranged from <0.10 to 0.12 ppm. Total mefenp yr - diethyl residues (sum of mefenpy r diethyl and parent equivalents of AE F113225, AE F109453, and AE F094270) ranged from <LLMM (0.40 ppm) to 1.34 ppm at a PHI of 0 day s in sorghum forage. Total residues of mefenp yr - diethyl and its metabolites were undetectable i n all sorghum grain and stover samples. The residue decline of mefenp yr - diethyl and its metabolite s with tim e in sorghum matrices could not be assessed due to residue levels below the LLMV. The results of the sorghum field trials are summarized in Table 7 below. Table 7 . Summary of Sorghum Residue Data fromCrop Field Trials with Mefenpyr - diethyl. Matrix Total

Applic. Rate (lb a.i./A) (kg a.i./ha) PHI 1 (days) Residue Levels 2,3,4 (ppm) n Min. Max. HAFT 5 Median (STMd) Mean

(STMR) Std.

Dev. 6 Me fenpyr - diethyl Sorghum Forage 0.020

(0.022) 0 24 <0.10 1.03 0.98 0.205 0.291 0.242

5 to 8 24 <0.10 <0.10 <0.10 <0.10 <0.10 N/A ECH ( 32 to 82) 24 <0.10 <0.10 <0.10 <0.10 <0.10 N/A Sorghum Grain 56 to 60 24 <0.01 <0.01 <0.01 <0.01 <0.01 N/A Sorghum Stover 56 to 60 24 <0.05 <0.05 <0.05 <0.05 <0.05 N/A AE F094270 Sorghum Forage 0.020

(0.022) 0 24 <0.10 <0.10 <0.10 <0.10 <0.10 N/A

5 to 8 24 <0.10 <0.10 <0.10 <0.10 <0.10 N/A ECH ( 32 to 82) 24 <0.10 <0.10 <0.10 <0.10 <0.10 N/A Sorghum Grain 56 to 60 24 <0.01 <0.01 <0.01 <0.01 <0.01 N/A Sorghum Stover 56 to 60 24 <0.05 <0.05 <0.05 <0.05 <0.05 N/AMefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 15 of 20 Table 7 . Summary of Sorghum Residue Data fromCrop Field Trials with Mefenpyr - diethyl. Matrix Total

Applic. Rate (lb a.i./A) (kg a.i./ha) PHI 1 (days) Residue Levels 2,3,4 (ppm) n Min. Max. HAFT 5 Median (STMd) Mean

(STMR) Std.

Dev. 6 AE F113225 Sorghum Forage 0.020

(0.022) 0 24 <0.10 0.12 0.11 <0.10 0.101 0.004

5 to 8 24 <0.10 <0.10 <0.10 <0.10 <0.10 N/A ECH ( 32 to 82) 24 <0.10 <0.10 <0.10 <0.10 <0.10 N/A Sorghum Stover 56 to 60 24 <0.05 <0.05 <0.05 <0.05 <0.05 N/A A E F109453 Sorghum Forage 0.020

(0.022) 0 24 <0.10 <0.10 <0.10 <0.10 <0.10 N/A

5 to 8 24 <0.10 <0.10 <0.10 <0.10 <0.10 N/A ECH ( 32 to 82) 24 <0.10 <0.10 <0.10 <0.10 <0.10 N/A Sorghum Stover 56 to 60 24 <0.05 <0.05 <0.05 <0.05 <0.05 N/A Total Mefenpyr - diethyl Sorghum Forage 0.020

(0.022) 0 24 <0.40 1.34 1.29 0.505 0.592 0.245

5 to 8 24 <0.40 <0.40 <0.40 <0.40 <0.40 N/A ECH ( 32 to 82) 24 <0.40 <0.40 <0.40 <0.40 <0.40 N/A Sorghum Grain 56 to 60 24 <0.02 <0.02 <0.02 <0.02 <0.02 N/A Sorghum Stover 56 to 60 24 <0.20 <0.20 <0.20 <0.20 <0.20 N/A 1 ECH = Earliest commercial harvest 2 LLMV = 0.10 ppm in forage, 0.01 ppm in grain, and 0.05 ppm in stover. LOD for mefenpyr - diethyl = 0.016 ppm for forage, 0.00166 ppm for grain, and 0.007 ppm for stover, and 0.0111 for hay. LOD for AE F094270 = 0.0142 pp m for forage, 0.00183 ppm for grain, and 0.0105 ppm for stover. LOD for AE F113225 = 0.0309 ppm for forage and 0.0231 ppm for stover. LOD for AE F109453 = 0.0214 ppm for forage and 0.0179 ppm for stover. 3 Total (ppm) for forage and stover = Sum of mefenpyr - diethyl (ppm), AE F094270 (ppm), AE F113225 (ppm) , and AE F109453 (ppm). Residues of AE F094270 (ppm) and AE F113225 (ppm) were undetectable (below the LLMV and LOD values). LLMV value was used in ca lculations when values were <LLMV 4 Total (ppm) for grain = Sum of mefenpyr - diethyl (ppm) and AE F109453 (ppm). LLMV value was used in calculations when values were <LLMV. 5 HAFT = Highest Average Field Trial. 6NA = not applicable because all replicates were <LLMV. The submitted grass and sorghum field trial data have been reviewed and are classified as scientifically

acceptable. An adequate number of trials were conducted in the appropriate geographical regions, and samples were anal yz ed for the residu es of concern using an adequate method. Storage stability data are also available to adequatel y support the storage durations and conditions from MRIDs 47815001 and 47815002. The residue data support the following recommended tolerances :

Grass, forage ................................ ................................ 1.6 ppm Grass, hay ................................ ................................ ..... 0.2 ppm Sorghum, forage ................................ ........................... 0.4 ppm Sorghum, grain ................................ .......................... 0.04 ppmMefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 16 of 20 Sorghum, stover ................................ .......................... 0.2 ppm 860.1520 Processed Food and Feed There are no proposed uses that are relevant to this guideline topic. 860.1650 Submittal of Analytical Reference Standards Analy tical standards for mefenpy r - diethyl, mefenpy

r dimeth ylmetabolite, mefenpy r ethyl methyl, and mefenp yr monoethyl (AEF113225) are currentl y avail able in the EPA National Pesticide Standards Repository (personal communication with Theresa Cole, 9/20/10). The anal yt ical standards for mefenp yr impurity and metabolite of mefenp yrdiethyl have expired, and Baye r is required to send an updated Certificate of Analy sis ( COA ) or a new standard. Baye r must ensure that anal yt ical standards are available for the parent chemical and all metabolites. Analy tical reference standards must be supplied and supplies replen ished as requested b y the Repository . The reference standards should be sent to the Analy tical Chemistry

L ab, which is located at Fort Meade, to the attention of either Theresa Cole or Thuy Ngu yen at the following address: USEPA National Pesticide Standards Repository /Anal yt ical Chemistry

Branch/OPP 701 Mapes Road Fort George G. Meade, MD 20755 - 5350 (Note that the mail will be returned if the extended zip code is not used.) 860.1850 Confined Accumulation in Rotational Crops Residue Chemistry M emo DP#s 238730, 271364, 264319, 276208, 11/22/02, Y. Donovan (PP# 7F04850) Adequate confined rotational crop studies were reviewed in PP#7F04850. [Phenyl 14 C] mefenp yr - diethyl was applied to soil at a rate significantly higher than the proposed use rate. Spinach, carrot, and wheat were planted back at 29 day s and 1 year. Based on the results of the residue uptakes, HED recommended a 30 - day PBI for leafy , fruiting, and root vegetables, and 12 - month PBI for all other crops other than wheat and barley , which can be replanted at any time. 860.1900 Field Accumulation in Rotational Crops DER Reference: 47140601.der.doc Residu e Chemistry Memo DP# 342071, 6/3/08, D. Davis (PP# 7E7224) The submitted limited field rotational crop data for field corn and so yb ean are adequate. The field rotational crop data for field corn will support a 90 - day plantback interval (PBI) with no need for rotational crop tolerances. The field rotational crop data for so ybean will support the established soy

bean and canola tolerances and a 120 - day PBI.Mefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 17 of 20 860.1550 Proposed Tolerances HED has previously

determined that the residues of concern for tolerance setting purposes in plant and livestock commodities are mefenp yr - diethyl parent and its three 2,4 - dichlorop hen yl py razoline metabolites ( HOE 113225, HOE 109453, and HOE 094270). Mefenp yr - diethyl tolerances for plant and animal commodities are listed in 40 CFR §180.509 (a) and are expressed in terms of the residues of the herbicide safener mefenp yr - diethyl (1 - ( 2,4 - dichlorophenyl) - 4,5 - dihydro - 5 - methyl - 1H - pyrazole - 3,5 - dicarboxylic acid, diethyl ester) and its 2,4 - dichlorophen yl py razoline metabolites at a rate of 0.053 pound safener per acre per growing season. The petitioner needs to submit a revised Section F to correct the tolerance expression to be consistent with the guidance issued 5/27/10 (S. Knizner) as well as the correct commodity definition for the requested crops . The tolerance expression should be changed as described below : Tolerances are establis hed for residues of the safener me fenpy r - diethyl, including its metabolites and degradates, in or on the commodities in the table below. Compliance with the tolerance levels specified below is to be determined by measuring only

the sum of mefenpy

r - diethyl (1 - (2,4 - dichlorophen yl ) - 4,5 - dihydro 5 - methyl - 1H - py

razole - 3,5 - dicarbox yl ic acid , diethyl ester) and its 2,4 - dichlorophen yl - py

razoline metabolites , calculated as the stoichiometric equivalent of mefenp yr - diethyl , in or on the commodity . In addition, the tolerances for canola seed, so yb ean seed, so ybean forage, and soybean hay should be moved from section (a) to section (d) . The introductory paragraph in section (d) should read as follows: Tolerances for are established for the indirect or inadvertent re sidues of mefenp yr - diethyl, including its metabolites and degradates, in or on the commodities identified in the following table below. Compliance with the tolerance levels specified below is to be determined by measuring only

the sum of mefenp yr - diethyl (1 - (2,4 - dichlorophen yl ) - 4,5 - dihydro - 5 - methyl - 1H - py razole - 3,5 - dicarbox yl ic acid , diethyl ester) and its 2,4 - dichlorophenyl - py razoline metabolites, calculated as the stoichiometric equivalent of mefenp yr - diethyl, in or on the commodity . No Codex, Canadian, or Mexican maximum residue limits (MRL s) are established for residues of mefenp yr - diethyl and metabolites in crop or livestock commodities. An International Residue Limit (IRL) form is appended to this Summary Document and follows this section. A summary of the recommended tolerances for the petition , to be listed in section (a), are listed in Table 8 .Mefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 18 of 20 Table 8 . Tolerance Summary for Mefenpyr - diethyl Commodity Proposed Tolerance (ppm) Recommended

Tolerance (ppm) Comments; Correct Commodity

Definition Grass Forage 1.5 1.6 Grass, forage Grass Hay 0.05 0. 2 Grass, hay Sorghum Forage 0.1 0. 4 Sorghum, forage Sorghum Grain 0.01 0.0 4 Sorghum, grain Sorghum Stover 0.05 0.2 Sorghum, stover References DP#s: 238730, 271364, 264319, 276208 Subject: PP# 7F04850: Safener HOE 107892 (mefenp yr - diethyl)

– Proposal for

Tolerances of Residues in/on Barley and Wheat: Analy

tical Method and Residue Chemistry

Review. From: Y. Donovan To: K. Bo yl e/R. Forrest Date: 11/22/02 MRIDs: 44302906 - 44302915 DP#s: 342071 Subject: Mefenp yr - diethyl (Safener HOE 107892). Petition for Establishment of

Rotational Tolerances for Soy bean and Canola. Summary of Anal yt ical Chemistry

and Residue Data. From: D. Davis To: Karen Angulo Date: 6/3/08 M RIDs: 47140601 DP#s: 358191 Subject: Mefenp yr - diethyl (Safener HOE 107892). Addendum to the Analy tical Chemistry

and Residue Data Summary to Support the Establishment of Rotational Tolerances for So ybean and Canola. From: D. Davis To: Karen Samek Date: 11/25/08 MRIDs: 45447701 DP#s: 286489 Subject: Safener HOE 107892 (mefenp yr - diethyl) Dietary Exposure Assessment for the Section 3 Registration Action from the use of HOE - 107892 on Barley and Wheat. From: Y. Donovan To: K. Bo yl e/R. Forrest Date: 11/22/02 MRIDs: NoneMefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 19 of 20 DP#s: 353114 Subject: Mefenp yr - diethyl (HOE 107892) Safener: Chronic Aggregate Dietary (Food and Drinking Water) Exposure and Risk Assessment for the Section 3 Registration Action to Add Soy

bean and Canola Rotational Crop Tolerances as a Result of In creased Application Rate. From: D. Davis To: Karen Angulo Date: 6/3/08 MRIDs: None DP#s: 380767 Subject: Mefenp yr - diethyl (HOE 107892) Revised Safener Chronic Aggregate Dietary

(Food and Drinking Water) Exposure and Risk Assessment for the Section 3 Registration Action to Add New Uses and Establish Tolerances on Sorghum and Grasses Grown for Seed. From: A. LaMay To: Bethan y Benbow Date: 2 /22/11 MRIDs : None Attachments: International Residue Limit Status sheetMefenpyr diethyl Summary of Analytical Chemistry and Residue Data Barcode: D380768

Page 20 of 20 

### International Residue Limits

Mefenpyr - diethyl (PC Code 811800; 10/06/10) Summary of US and International Tolerances and Maximum Residue Limits Residue Definition : US Canada Mexico 2 Codex 3 40 CFR 180.509: Plant/L ivestock: mefenpyr - diethyl, 1 - (2,4 - dichlorophenyl) - 4,5 - dihydro - 5 - methyl - 1H - pyrazole - 3,5 - dicarboxylic acid, diethyl ester and its 2,4 - dichlorophenyl pyrazoline metabolites. None None

Commodity 1 Tolerance (ppm) /Maximum Residue Limit (mg/kg) US Canada Mexico 2 Codex Grass, forage 1.6 Grass, hay 0.2 Sorghum, forage 0.4 Sorghum, grain 0.04 Sorghum, stover 0.2

Completed: M. Negussie; 10/06/2010 1 Includes only commodities of interest for this action. Tolerance values are the HED recommendations and not those proposed by the applicant. 2 Mexico adopts US tolerances and/or Codex MRLs for its export purposes. 3 * = absent at the limit of quantitation; Po = postharvest treatment, such as treatment of stored grains. PoP = processed postharvest treated commodity, such as processing of treated store d wheat. (fat) = to be measured on the fat portion of the sample. MRLs indicated as proposed have not been finalized by the CCPR and the CAC.