Clopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 1 of 19 UNITED STATES ENVIRONMENTA L PROTECTION AGENCY

WASHINGTON, D.C. 20460 OFFICE OF PREVENTION, PESTICIDE AND TOXIC SUBSTANCES MEMORANDUM Date : 27 October 2009 SUBJECT: Clopyralid

– Petition for Tolerances on Swiss chard, Bushbe rry Subgroup 13 - 07B, and Strawberry

(Regional Restriction). Summary of Anal ytical Chemistry and Residue Data . PC Code: 117401 ( alkanolamine salts ), 117403 ( acid) DP Barcode: D 361787 Decision No.: 403248 Registration Nos. : 62719 - 80, 62719 - 81, and 627 19 - 84 Petition No.: 8E7481 Regulatory Action: Section 3 and 24(c) Registrations Risk Assessment Type: NA Case No.: NA T XR No.: NA CAS Nos.: 1702 - 17 - 6 (acid) 577 5 4 - 85 - 5 (monoethanolamine salt) MRID No.: See MRID Summary Table 40 CFR: 180.431 FROM: Michael A. Doherty, Ph.D., Chemist

Risk Assessment Branch II Health Effects Division (7509P) THROUGH: William Drew , Chemist

Risk Assessment Branch II Health Effects Division (7509P) TO: Barbara Madden, RM 05

Risk Integration, Minor Use & Emergency Response Branch Registration Division (7505P) MRID Summary Table MRID No. Study Type Comments 47604401 860.1500 Swiss chard New DER 47604401.der 47604402 860.1500 blueberry New DER 47604402.der 47604403 860.1500 straw berry New DER 47604403.der This document was originally prepared under contract by Dy namac Corporation ( 1910 Sedwick Road , Building 100, Suite B; Durham, NC 27 713 ). The document has been reviewed b y the Health Effects Division (HED) and revised to reflect current Office of Pes ticide Programs (OPP) policies.Clopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 2 of 19 Executive Summary Clopy ralid [3,6 - dichloro - 2 - py

ridinecarboxylic acid] is a py ridine herbicide register ed for use on a variety of food and feed crops in the U.S. for the postemergen ce control of broadleaf weed s , particularl y thistles and clover. Permanent tolerances are established for residues of clopy ralid in/on a wide variety of plant commodities at lev els ranging from 0.5 ppm in/on stone fruits to 500 ppm in/on grass forage and hay [40 CFR §180.431(a)], including a tolerance of 1.0 ppm for strawberry . Permanent tolerances are also established for residues of clopy ralid in livestock commodities at level s ranging from 0.1 ppm in eggs to 36 ppm in meat b yp roducts, except liver, of cattle, goats, horses and sheep . There currentl y are no tolerances for inadvertent or indirect residues of clop yr alid. The Interregional Project No. 4 (IR- 4) has submitted a p etition proposing the use of the 3 lb acid equivalent (ae)/gal emulsifiable concentrate (EC) formulation of the monoethanolamine salt of clopy ralid (Stinger® ; EPA Reg. No. 62719 - 73 ) o n Swiss chard, members of the bushberry subgroup (13 - 07B), and strawberri es (FL and NC only). The proposed use on Swiss chard is for a single broadcast foliar application no later than the 8 - leaf stage at 0.094 - 0.187 lb ae/A , and the proposed use on bushberries is for two soil - directed applications beginning one week after blo om at up to 0.2 5 lb ae/A/application for a maximum of 0.5 lb ae/A/season , with a minimum retreatment interval (RTI) of 14 days. The proposed use on strawberries is for a single broadcast foliar application at 0.113 - 0.25 lb ae/A at up to 7 day s prior to harvest; this use is restricted to strawberries grown in FL and NC under an annual - ty pe production s ys tem. All uses allow for applications using onl y ground equipment. The proposed minimum preharvest intervals ( PHIs ) are 30 d ay s for Swiss chard and bushberries, and 7 day s for strawberries. Inconjunction with the proposed uses on Swiss chard and bushberries, IR- 4 is proposing the following permanent tolerances for clop yr alid:

Swiss chard ................................ ................................ .......... 5.0 ppm Bushberry

subgroup 13 - 07B ................................ ................ 6.0 ppm For the proposed use on s trawberries, IR - 4 is proposing the following permanent tolerance for clopy ralid with a regional restriction: Strawberry

(annual) ................................ ............................. 4.0 ppm Based on the available cabbage, grass, wheat and barley metabolism studies, the nature of clopy ralid residues in plants is adequatel y understood for purposes of this petition. The residue of concern in plants for both risk assessment and the tolerance expression is clopy ralid. As the crop uses being proposed in this petition do not include any regulated livestock feed stuffs, issues pertaining to residues in livestock commodities are not relevant to the current petition. An adequate gas chromatograph/electron - capture detection (GC/ECD) method ( Method ACR 75.6 ) is available for enforcing tolerances for clopy ralid in/on plant commodities . In the submitted Swiss chard, blueberry and strawberry

field trials, residues of clopy ralid in/on each commodity

were determined using a slightl y modified version of the current enforcementClopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 3 of 19 method. Th e method was adequatel y validated in conjunction with the analy sis of field trial samples , and the lowest level of method validation (LLMV) was 0.05 ppm for each crop . The submitted Swiss chard, blueberry and strawberry field trial data are adequate and support the proposed uses. An ade quate number of tests were conducted on each crop in the appropriate geographic regions at ~1x the maximum proposed rate, and the appropriate samples were collected from each test around the proposed PHI. Residues of clop yralid in/on each commodity were d etermined using an adequate GC/ECD method, and the duration and conditions of sample storage are supported b y the available storage stability data. The available field trial data support tolerances of 3.0 ppm for Swiss chard, 0.50 ppm for the bushberry subgroup 13 - 07B, and 4.0 ppm for strawberries. No processing data are required to support the proposed uses, and the existing confined rotational crop study adequately supports the rotational crop restrictions specified on the current label. Regulatory Recommendations and Residue Chemistry Deficiencies Provided the label is modified to exclude use on low - growing varieties of bushberry , there are no deficiencies in the subject petition that would preclude establishing permanent tolerances for residues of clop yr alid on the proposed commodities. The residue chemistry data support tolerances for clop yr alid at 3.0 ppm in/on Swiss chard and at 0.50 ppm in/on the bushberry subgroup 13 - 07B, except low - bush varieties. Based on the available data, the existing tolerance of 1.0 ppm in/on strawberry should be increased to 4.0 ppm to support the proposed use pattern in FL and NC (see Table 6). HED notes that although a tolerance for the bushberry subgroup 13 - 07B would include cranberry , the existing tolerance for residues in/on cranberry should remain due to use pattern differences between cranberry and the bushberry

subgroup. HED notes that the recommended tolerances on bushberry and strawberry

are not harmonized with Canadian MRL s. There are n o residue chemistry considerations that would preclude granting the regional registrations for clop yr alid. A human health risk assessment for clop yr alid is forthcoming. The tolerance definition for clopy ralid should be revised to read as follows: Toleran ces are established for residues of the herbicide clopy ralid , including its metabolites and degradates, in or on the commodities in the table below as a result of the application of clopy

ralid . Compliance with the tolerance levels specified below is to be determined b y measuring only clopy ralid [ 3,6 - dichloro - 2 - py

ridinecarbox yl ic acid ] in or on the commodity . Background Clopy ralid is a selective, postemergence py ridine herbicide that is used for the control of broadleaf weed s , particularly thistles and cl over , in a variety of crops . In the current petition (PP#8E7481), IR - 4 is proposing to expand the use of clopy ralid to include applications to Swiss chard and bushberries for the postemergence control of various weeds. In addition, IR - 4 is proposing a re gionall y restricted use on strawberries grown onl y in FL and NC under an annual ty pe production sy stem . There is currentl y a use on strawberries grown as a perennial crop (DP# 270507, 8/6/2002, D. Dotson). The chemical structure and nomenclature of theClopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 4 of 19 m onoethanolamine salt of clopyralid is summarized in Table 1, and the physicochemical properties of clopy

ralid are summarized in Table 2. T able 1. Clopyralid Nom enclature. Compound N Cl Cl O O O H NH 3 + Common name Clopyralid , monoethanolamine salt Company experimental name Dowco 290 IUPAC name 3,6 - dichloropyridine - 2 - carboxylic acid, monoethanolamine salt CAS name 3,6 - dichloro - 2 - pyridinecarboxylic acid, monoethanolamine salt CAS registry number 1702 - 17 - 6 (acid) 577 5 4 - 85 - 5 (monoethanolamine salt) End -use product (EP) 3 lb ae/gal EC (Stinger® herbicide ; EPA Reg. No. 62719 - 73) T able 2. Physicochemical Properties of Technical Grade Clopyralid Acid. Parameter Value Reference Melting point/range 149.6 D ata were obtained from the FOOTPRINT Pesticide Properties DataBase, (http://www.eu footprint.org/ppdb.html ) . pH Not available Density (specific gravity) 1.76 g/mL Water solubility (g/L) at 20°C 143 Solvent solubility (g/L) at 20°C Acetone

– 250 Ethyl ac e tate

– 10 2 Xylene

– 4.6 Hexane

– 6.0 Vapor pressure at 25°C, mPa 1.36 Dissociation constant, pKa , at 25°C 2.01 Octanol/water partition coefficient, Log(KOW) , at 20°C - 2.63 UV/visible absorption spectrum Not available 860.1200 Directions for Use A 3.0 lb ae/gal EC formulation of clopy ralid is currently

registered to Dow AgroSciences (Stinger ® ; EPA Reg. No. 62719 - 73) for use on a wide variety of crops for the postemergence control of weeds . IR - 4 is proposing new uses for this formulation on Swiss chard and members of the bushberry

subgroup . Although there is an existing use for clopy ralid on perennial strawberries, with a 30 - day PHI , IR - 4 is also proposing to establish a new use for strawberries grown under an annual production sy stem in the states of N C and FL. Ex amples of supplemental labels for the 3 lb ae/gal EC were provided, and the proposed use directions are summarized below in Table 3.Clopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 5 of 19 Table 3. Summary of Directions for Use of Clopyralid . Applic. Timing, Type, and Equip. 1 Formulation [EPA Re g. No.] Applic. Rate

(lb ae/A) Max. No.

Applic. per Season Max. Seasonal

Applic. Rate (lb ae/A) PHI

(days) Use Directions and

Limitations 2 Swiss Chard Broadcast foliar application when crop is at the cotyledon to 8 - leaf stage of growth; ground equipment. 3.0 lb ae/gal EC [62719 - 73] 0.094 - 0.187 1 0.187 30 Apply in a minimum of 10 gal/A Bushberry subgroup 13 - 07B Directed applications to row middles beginning 1 week after bloom; ground equipment 3.0 lb ae/gal EC [62719 - 73] 0.06 - 0.25 2 0.5 30 Apply in a minimum of 1 0 gal/A, with a minimum RTI of 14 days. Do not apply by aircraft. Strawberry ( annual fields only in FL and NC ) Broadcast foliar application to well - established plantings; ground equipment 3.0 lb ae/gal EC [62719 - 73] 0. 113 - 0.25 1 0.25 7 Apply in a minimum of 20 gal/A. Do not use with a surfactant. Do not apply by aircraft 1 Do not apply through any type of irrigation system. 2 The label for the 3 lb ae/gal EC contains the following rotational crop restrictions: barley, canola, cole crops, f lax, garden beets, grasses, corn (field, pop and sweet), oats, spinach, sugar beets, turnips and wheat may be planted at anytime followin g a treated crop. Depending on the amount of soil organic matter, rainfall and location (state), the plant -back interv als for all other crops range from 10.5 to 18 months. Conclusions . The labels are adequate to allow evaluation of the residue data relative to the proposed use s . The available field trial data support the proposed use directions , although the label should be revised to exclude use on low - growing varieties of bushberry . 860.1300 Nature of the Residue - Plants DP # 270507 , 8/ 6/2002 , D. Dotson The nature of the residue in plants is adequatel y understood for purposes of this petition based on the accepta

ble cabbage, grass, barley and wheat metabolism studies . Ineach of these studies, the major 14 C - residue was determined to be only parent compound. Although data are available for only two dissimilar crops (leafy vegetable and cereal grain), HED has conc luded that the residue of concern in plants for purposes of this petition is clopy ralid. However, the Agency reserves the right to require additional metabolism studies in the future should the petitioner request the establishment of clopy

ralid tolerances for additional crops. 860.1300 Nature of the Residue - Livestock There are no livestock feedstuffs associated with the proposed use on Swiss chard, bushberry subgroup 13 - 07B, and strawberry . Therefore, data requirements for livestock metabolism are no t relevant to this tolerance petition . 860.1340 Residue Analytical MethodsClopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 6 of 19 Enforcement method . The Pesticide Anal ytical Manual (PAM) Vol. II lists a GC/ECD method for determining residues of clopy ralid residues in/on plant commodities (Method Ior Metho d ACR 75.6). For this method, residues are extracted with dilute NaOH (0.25% or 0.1%) and filtered. The extract is then acidified and salinized, and residues are partitioned into ethyl ether. Residues are then methylated using diazomethane and cleaned u p on an activated Alumina column. Residues are then determined b y GC/ECD using external standards. The reported LOQs are 0.5 ppm for grains and 2.0 ppm for green forage. Data collection methods . Inthe submitted field trials, residues of clopy ralid in/on samples of Swiss chard, blueberries and strawberries were determined using a slightl y modified version of the current tolerance enforcement method. For each commodity, residues were extracted with 0.5% NaOH and centrifuged. The resulting extract was acidified with HCl and salinized with NaCl, and residues were partitioned into ethyl ether. Residues were then m ethylated using diazomethane, concentrated to dry ness, re - dissolved in toluene, and cleaned up using an activated Alumina A column eluted with t oluene . The methylated residues were anal yz ed b y GC /ECD using external standards . Residues are expressed in terms of parent clop y ralid using a conversion factor of 0.93. The lowest level of method validation (LLMV) for clopy ralid in each commodity

was 0 .05 ppm. The calculated LO Qs were 0.052 - 0.073 ppm and the LODs were 0.017 - 0.024 ppm. The above method was adequatel y validated using control samples of each matrix fortified with clopy ralid at 0.05 - 5.0 ppm . Acceptable recoveries were obtained for each m atrix, and the fortification levels bracketed the measured residue levels. Apparent residues of clop yralid were <LOQ in/on control samples, which the exception of two control samples from one of the blueberry field trials which had apparent residues o f cl opy ralid at 0.060 and 0.055 ppm. Conclusions . An adequate GC/ECD method (Method ACR 75.6) is available for enforcing the proposed tolerances and collecting data on residues of clop yralid in Swiss chard, blueberries and strawberries. 860.1360 Multiresidu e Methods The FDA Pestrak database (PAM Vol. I, Appendix dated 11/6/90) indicates that the existing FDA multiresidue methods are not likel y to recover clop yr alid. HED notes that clopy ralid does appear to be adequatel y recovered b y the “QuEChERS” multires idue method (http://www.quechers.com). 860.1380 Storage Stability DP # 270507 , 8/ 6/2002 , D. Dotson Under frozen storage conditions, clopy ralid has been shown to be stable in plant commodities for the following durations: 50 months in safflower seeds, so y beans, sugar beet roots and tops, and oat forage, grain and straw; 30 months in strawberries; 26 months in dried hops cones; 16Clopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 7 of 19 months in cherries and plums; 15 months in canola meal; 10 months in canola seed and oil; 9 months in cabbage and spinach; 5 months in mustard greens; and 3 months in peaches. Samples collected from the submitted field trials were stored frozen within 3 hours after harvest, shipped frozen to the analy tical laboratory

2 - 40 day s later, and stored at - 21°C at the anal ytical laboratory until anal ys is. The maximum frozen storage intervals, from harvest to analy sis of samples, are listed in Table 4. Table 4 . Summary of Storage Conditions and Durations of Samples from Crop Field Trial Studies. Matrix Storage

Tem perature (°C) Actual Storage Duration (days) Interval of Demonstrated Storage Stability (months) Swiss Chard - 21 ± 7 41 - 91 5 (Mustard Greens) Blueberry - 21 ± 7 41 - 132 16 (Cherry) Strawberry - 21 ± 7 90 - 99 30 (Strawberry) Conclusions . Adequate storage stability data are available to support the sample storage conditions and durations in the submitted field trials. 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 . 860.1480 Meat, Milk, Poultry, and Eggs There are no livestock feedstuffs assoc iated with the proposed use on Swiss chard, bushberry subgroup 13 - 07B and strawberry . Therefore, data requirements pertaining to meat, milk, poultry , and eggs are not relevant to this tolerance petition . 860.1500 Crop Field Trials 47604401.der (Swiss Chard) 47604402.der (blueberry) 47604403.der (straw

berry) IR - 4 has submitted new field trial data supporting the proposed uses of clopy ralid (3 lb ae/gal EC) on Swiss chard and members of the bushberry subgroup 13 - 07B. Although there is an existing use for clop yralid on strawberries grown under a perennial cropping s ys tem , IR - 4 is requesting a new use on strawberries grown in FL an d NC under an annual production sy stem. New strawberry

field trial data have been submitted to support this new use . The results from these field trials are discussed below and the residue data are summarized in Table 5.Clopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 8 of 19 Table 5. S ummary of Residue Data fromCrop Field Trials with Clopyralid (EC). Crop matrix Total Applic.

Rate (lb a e/A) PHI

(days) Residue Levels (ppm) 1

n Min. Max. HAFT 1 Median Mean Std. Dev. Swiss Chard (proposed use = 0.187 lb a e/A total application rate, 30 - day PHI) Swiss Chard 0.093 - 0.103 28 - 29 8 0.05 0.70 0.62 0.34 0.34 0.22

0.188 - 0.199 8 <0.05 1.90 1.60 0.57 0.69 0.69 Bushberry subgroup 13 - 07B (proposed use = 0.5 lb a e/A total application rate, 30 - day PHI) Blueberry 3 0.483 - 0.525 27 - 33 14 < 0.05 0 .42 0.38 0.06 0. 12 0.12 Strawberry , grown in FL and NC only (proposed use = 0.25 lb a e/A total application rate, 7 - day PHI) Straw berry 0.119 - 0.125 7 - 8 6 0.79 1.80 1.70 0.98 1.18 0.42

0.246 - 0.255 6 1.60 3.00 2.85 2.40 2.35 0.53 1 Residues are express ed in terms for clopyralid acid. The LLMV for clopyralid was 0.05 ppm. For all calculations, 0.05 ppm was used for any residue values <LLMV. 2 HAFT = Highest Average Field Trial. 3 Residues from the field trial in ME, which used a foliar application, have not been included in the summary of residue data. Swiss Chard. Four field trials were conducted on Swiss chard in Zones 1, 2 and 11 during the 2002 growing season. In side - by- side tests at each site, the monoethanolamine salt of clop yralid ( 3.0 lb ae/g al EC) was applied to Swiss chard as a single broadcast foliar application during vegetative development at rates of 0.093 - 0.103 lb ae/A or 0.188 - 0199 lb ae /A (0.5 and 1.0x the proposed rate) . Applications were made using ground equipment in volumes of 16 - 60 gal/A, without the use of a spray adjuvant . Single control and duplicate treated samples of Swiss chard (leaves and petioles) were harvested from each plot at commercial maturity, 28 - 29 day s after treatment (DAT). Samples were stored at ≤ - 21°C fo r up to 3 months from harvest to anal ys is; a duration that is supported by

the available storage stability data. Samples were anal yz ed for residues of clopy ralid using an adequate GC/ECD method, which is a slightly modified version of the current toleranc e enforcement method (Method ACR 79.5) . The lowest level of method LLMV for clop yralid in Swiss chard was 0.05 ppm. Following a single broadcast foliar application of clopy ralid (EC), residues in/on Swiss chard harvested at 28 - 29 DAT were 0. 05 - 0.70 ppm at the 0. 5x rate and <0.05 - 1.90 ppm at the 1x rate. For the 0.5x and 1x use rates, average residues were 0.34 and 0.69 ppm, respectivel y, and the HAFT residues were 0.62 and 1.60 ppm. A residue de cline study was not conducted. B ushberry Subgroup 13 - 07. Nine blueberry field trials were conducted in Zones 1 , 2, 5 and 12 during the 1999 and 2000 growing seasons. Lowbush ty pe blueberries were treated at the one test site in ME (Zone 1), and highbush type blueberries were treated at all the other test sites. At each site, the monoethanolamine salt of clopy ralid (3 lb ae/gal) was applied to blueberries as two applications during earl y fruit development at rates of 0.240 - 0.264 lb ae/A , for a total rate of 0.490 - 0.525 lb ae/A/season (1x proposed rate) . For the lowbush blueberry test, the two applications were made as broadcast foliar applications. For the highbush blueberry tests, the two applications were made as directed applications to the ground between the crop rows, avoiding contact with the bushes. App lications were made at RTIs of 12 - 21 using groundClopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 9 of 19 equipment in volumes of 20 - 31 gal/A, without the use of a spray adjuvant. Single control and duplicate treated samples were harvested from each site at commercial maturity , 27 - 33 DAT. Samples were stored at ≤ - 21°C for up to 4.3 months from harvest to analy sis; an interval that is supported by

the available storage stability data. Samples were anal yz ed for residues of clopy ralid using an adequate GC/ECD method, which is a slightly modified version of the current tolerance enforcement method (Method ACR 79.5) . The LLM V for clopy ralid in blueberries was 0.05 ppm. The residue data from one of the tests (Trial MI16) were excluded from the dataset because clopy ralid residues were found in controls samples at levels similar to the residue levels in the associated treated samples. These data were not used in determining a recommended tolerance level (see Appendix II). Following two broadcast foliar application of clopyralid (EC) totaling 0.4 9 lb a e/A, residues were 4.7 and 5.8 ppm in/on blueberries harvested at 2 8 DAT. Following soil - directed application at rates ranging from 0.48 to 0.53 lb ae/A, residues were <0.05

– 0.42 ppm in/on blueberries harvested 27 - 33 DAT. Not including the foliar treatment, the average residue w as 0. 11 pm and the highest average field trail (HAFT) residue was 0.38 ppm. A residue decline study was not conducted. Strawberry (annual production system in FL and NC only) . Three field trials were conducted in Zones 2 and 3 during the 2 002 growing season on strawberries growing in an annual - ty pe production sy stem . In side - by- side tests at each site, the monoethanolamine salt of clopy ralid ( 3.0 lb ae/ gal EC) was applied to strawberries as a single broadcast foliar application during frui ting at rates of 0. 119 - 0.125 lb ae/A or 0. 246 - 0.255 lb ae/A (0.5x and 1x the proposed use rate) . Applications were made using ground equipment in volumes of 29 - 35 gal/A, without the use of a spray

adjuvant . Single control and duplicate treated samples of strawberries were harvested from each plot at commercial maturity, 7 - 8 DAT. Samples were stored at ≤ - 21°C for up to 3 months from harvest to anal ys is; a duration that is supported by

the available storage stability data. Samples were anal yz ed for residu es of clopy ralid using an adequate GC/ECD method, which is a slightly modified version of the current tolerance enforcement method (Method ACR 79.5) . The LLM V for clopy ralid in strawberries was 0.05 ppm. Following a single broadcast foliar application of clopy ralid (EC), residues in/on strawberries harvested at 7 - 8 DAT were 0. 079 - 0.180 ppm at the 0.5x rate and 1.60 - 3.00 ppm at the 1x rate. For the 0.5x and 1x rates, average residues were 1.18 and 2.35 ppm, respectively , and the HAFT residues were 1.70 an d 2.85 ppm. A residue de cline study was not conducted. Conclusions . The Swiss chard, blueberry and strawberry field trials are adequate and support the proposed use patterns. An adequate number of tests were conducted in the appropriate geographical regions, and samples were anal yz ed for the residue of concern using an adequate data collection method. Adequate storage stability data are available to support the storage conditions incurred in the field trials. The data support tolerances of 3.0 ppm in/on Swiss chardClopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 10 of 19 and 0.50 ppm in/on bushberries, provided low - growing varieties are excluded. The data also support a 4.0 ppm in/on strawberries, with a regional restriction to FL and NC. The label should be revised to prohibit use on low - growing varietie s of bushberries since their morphology does not readily

allow for soil applications. Furthermore, directions for a previously established use on cranberry

(a member of the bushberry group) are significantl y different than the currently proposed use; ther efore, the existing tolerance for cranberry should remain even if a tolerance for the bushberry

subgroup is established. 860.1520 Processed Food and Feed HED does not require residue data for any process ed commodities associated with Swiss chard, bushber ry subgroup 13 - 07B, and strawberry . Therefore, data requirements for processed food and feed are not relevant to this tolerance petition . 860.1650 Submittal of Analytical Reference Standards An anal ytical standard for clopy ralid is currently

available in the EPA National Pesticide Standards Repository

(personal communication with Dallas Wright, ACB, 6/12/2009). 860.1850 /1900 Confined and Field Accumulation in Rotational Crops DP # 193219, 8/4/93, G. Kramer An acceptable confine d rotational crop study is available for clopy

ralid. In this study, the total radioactive residues in/on representative rotational crop commodities (lettuce, turnips, green beans, and wheat) were below 0.01 ppm at plant - back intervals of 49 - 98 day s follow ing application of [ 14 C]clopy

ralid to the soil at 0.29 lb ae/A (1.17x the maximum seasonal rate for crops which can be rotated). The current label for the 3 lb ae/gal EC of clop yr alid allows for the replanting of the following crops at anytime: barley , canola, cole crops, flax, garden beets, grasses, corn (field, pop and sweet), oats, spinach, sugar beets, turnips and wheat. The plant - back interval for all other crops is 10.5 to 18 months d epending on the amount of soil organic matter, rainfall and loc ation (state) . The established rotational crop restrictions are adequate. Limited field rotational crop studies are not required, and no tolerances are required for inadvertent or indirect residues in rotational crops. 860.1550 Proposed Tolerances Perm anent tolerances are established for residues of clopy ralid in/on a wide variety of plant commodities at levels ranging from 0.5 ppm in/on stone fruits to 500 ppm in/on grass forage and hay [40 CFR §180.431(a)], including a 4.0 ppm tolerance on cranberry , which is a member of the bushberry subgroup 13 - 07B, and a 1.0 ppm tolerance on strawberry . Permanent tolerances are also established for residues of clop yralid per se in livestock commodities at levels ranging from 0.1 ppm in eggs to 36 ppm in meat by prod ucts, except liver, of cattle, goats, horses and sheep .Clopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 11 of 19 Currently there are no tolerances for inadvertent or indirect residues of clopy ralid. A summary of the recommended tolerances for the petition are listed in Table 6. An adequate number of field tri als at ~1x the proposed use rate are available for Swiss chard and blueberries to support permanent tolerances on Swiss chard and the bushberry subgroup 13 - 07B (except low - growing varieties), of which blueberry is the representative crop. An adequate numb er of strawberry

field trials were also conducted in Zones 2 and 3 at 1x the proposed use rate to support a tolerance with a regional restriction to NC and FL. The Agency ’s SOP “ Guidelines for Setting Pesticide Tolerances Based on Field Trial Data” were utilized for determining the appropriate tolerance level for each commodity (Appendix II). The recommended tolerances on Swiss chard and the bushberry subgroup 13 - 07B (except low growing varieties) are 3.0 and 0.50 ppm, respectively . On strawberries, the new use pattern results in a recommended tolerance of 4.0 ppm. As previously noted, the current tolerance for cranberry at 4.0 ppm should remain even if tolerances for the bushberry subgroup are established. There are no Codex or Mexican maximum residue limits (MRL s) for residues of clopy ralid in/on the requested commodities (Appendix I). However, there are Canadian MRL s for residues of clopy ralid at 1.0 mg/kg on strawberry and 0.1 mg/kg on blueberry . The Canadian MRLfor strawberry

harmonizes with the existing tolerance on strawberry . Based on the proposed use on strawberry

and bushberries, and the available residue data, the recommended tolerances on strawberry

and bushberries (subgroup 13 - 07B) cannot be harmonized with the Canadian MRL s. Table 6 . T olerance Summary for Clopyralid. Commodity Proposed/Existing Tolerance (ppm) Recommended

Tolerance (ppm) Comments; Correct Commodity

Definition 40 CFR §180.431(a) Swiss Chard 5.0 3.0 Adequate field trail data are available. B ushberry subgroup 13 - 07B 6. 0 0.50 Adequate field trail data are available; however, the tolerance should be for the subgroup except low - growing varieties . Cranberry 4.0 4.0 The tolerance on cranberries should remain due to differences in use pattern and residue level versus the currently proposed use on bushberry Straw berry 4.0 4.0 Adequate field trial data are available to support a 7 - day PHI on strawberries grown under an annual - ty pe production system in FL and NC only. This tolerance will supersede the existing 1.0 -ppm tolerance already established on straw berry (grown under a perennial production system).Clopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 12 of 19 References DP Number: 193219 Subject: ID # 062719 - 00073. Review of Confined Rotational Study of Clopy ralid. From: G. Kramer To: J. Miller Date: 8/4/93 MRID: 42815001 DP Number: D270507 Subject: Clopy

ralid. Review of Residue Chemistry Data in Support of Permanent or Time - Li mited Tolerances Proposed for Canola (PP#1E6291), Cherries (PP#1E6329), Crambe (PP#1E6291), Cranberry (PP#1E6340), Flax (PP#1E6227), Garden Beets (P P#1E6333), Head and Stem Brassica (PP#1E6999), Hops (PP#1E6283), Mustard Greens (PP#1E6334), Peaches (PP#1E6329), Plums (PP#1E6329), Spinach (PP#1E6320), Strawberries (PP#1E6241), Sweet Corn (PP#4F4379), Popcorn (PP#4F4379), and Turnips (PP#1E6335). From: Douglas A. Dotson To: S. Brothers/R. Forrest Date: 8/6/2002 MRID: 41904401, 41904402, 41904403, 44212601, 45036101, 45259901,

45372801, 45372802, 45390001, 45419801, 45436901, 45436902, 45436903, 45446901, 45447001, 45447101, 45473601, and IR - 4 Rpt No. PR 07223 Attachments: Appendix I - International Residue Limit Status sheet Appendix I I - Tolerance Assessment CalculationsClopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 13 of 19 Appendix I. International Residue Limit Status S heet 

## INTERNATIONAL RESIDUE LIMIT STATUS Chemical Name: 3,6 - dichloro - 2 - pyridinecarboxylic acid Common Name: Clopyralid X Recommended tolerances ⁯ Reevaluated tolerance ⁯ Other Date: 07 /20 /09 Codex Status (Maximum Residue Limits) U. S. Tolerances √ No Codex proposal step 6 or above ⁯No Codex proposal step 6 or above for the crops requested Petition Number: PP# 8E7481 DP #s: 361787 Other Identifier: Residue definition (step 8/CXL): NA Revie wer/Branch: M. Doherty, HED/RAB2 Residue definition: Clopyralid Crop (s) MRL (mg/kg) Crop(s) Tolerance (ppm) Bushberry, subgroup 13 - 07B 0.5 Straw berry 4.0 Swiss chard 3.0

Limits for Canada Limits for Mexico ⁯ No Limits ⁯ No Limits for the crops requested ⁯ No Limits √ No Limits for the crops requested Residue definition: Clopyralid Residue definition: NA Crop(s) MRL (mg/kg) Crop(s) MRL (mg/kg) Blueberry 0.1 Straw berry 1.0

Notes/Spec ial Instructions:Clopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 14 of 19 Appendix II. Tolerance Assessment Calculations. For each of the crops listed below, the Guidance for Setting Pesticide Tolerances Based on Field Trial Data ( SOP ) , along with the tolerance spreadsheet, was used for calculating recomm ended tolerances. As specified in the SOP, the minimum of the 95% upper confidence limit (UCL) on the 95 th percentile and the point estimate of the 99 th percentile was selected as the tolerance value in cases when the dataset was large (greater than 15 samples) and reasonably lognormal. For datasets that were small ( ≤15 samples) and reasonably lognormal, the upper bound estimate of the 95th percentile based on the median residue value was compared to the minimum of the 95% UCLon the 95th percentile and the point estimate of the 99th percentile, and the minimum value was selected as the tolerance value. For datasets that were not lognormal, the upper bound on the 89 th percentile was selected as the tolerance value (distribution - free method). The rounding procedures specified in the SOP were also used. Swiss c hard . The dataset used to establish a tolerance for clop yr alid on Swiss chard consisted of field trial data representing a single application at rates of 0.19 - 0.20 lb ae/A with a 28 - 29 - day PHI . As specified by

the SOP, the field trial application rates and PHIs are within 25% of the maximum label application rate and minimum label PHI , respectively . The residue values used to calculate the tolerance are provided in Table II - 1 . All but 2 field trial sample results for Swiss chard were above the LOQ (0.05 ppm). The Swiss chard dataset was small (8 samples). The dataset was entered into the tolerance spreadsheet. Although the result from the approximate Shapiro - Francia test statistic (Figure I - 2 ) indicated that the assumption of lognormality should not be rejected , v isual inspection of the lognormal probability

plot (Figure II - 1 ) provided in the spreadsheet indicate d that the dataset was not reasonabl y lognormal . Using the tolerance spreadsheet, th e recommended tolerance is 3.0 ppm on Swiss chard .

Table II - 1. Residue data used to calculate tolerance for Clopyralid on Swiss Chard. Regulator: EPA Che mi cal: Clopyralid Crop: Swiss Chard PHI: 28 - 29 days App. Rate: 1 application at 0.19 - 0.20 lb ae/A Submitter: IR- 4 MRID Citation: MRID 47604401 Residues 0.05 0.05 0.12 0.21 0.92 0.99 1.3 1.9Clopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 15 of 19 Figure II - 1 . Lognorm al probability plot of Clopyralid field trial data for Swiss chard. Lognormal Probability Plot

99.9 99 98 95 90 80 70 50 30 20 10 5 2 1 0.1 2.0000 1.0000 0.5000 0.2500 0.1250 0.0625 0.0313 y = 1.5208x - 1.1077 R 2 = 0.9014

PercentilesConcentrations EPA Clopyralid Swiss Chard 28-29 days 1 at 0.188-0.199 lb ai/A IR-4 MRID 47604401

Figure II - 2. Tolerance spreadsheet summary of Clopyralid field trial data for Swiss Chard . Regu lator : EP A Che mical : Cl opyra lid Crop : Sw iss Char d PHI : 28 -29 d ays App. Rate :

1 at 0.18 8-0.1 99 l b ai/ A Subm itter : IR-4 MRID Cit ation : MRI D 476 0440 1

n: 8 min : 0.05 max : 1.90 me dian ; 0.57 av erage : 0.69 95th Perc enti le 99t h Pe rcent ile 99 .9th Perc enti le 1.9 2. 5 3.0 (3.0 ) (4 .0) (- -) 4.0 11 35 (4 0) (2 20) (- -) 2. 5 3. 0 UP LMe dian9 5th 6. 0 0.901 4 p- value > 0 .05 : Do not rejec t lo gnorm alit y as sumpt ion

Y EU Me thod I Norma l EU Me thod I Lo g Nor mal

Wou ld y ou l ike t he a bove valu es rou nded ? (Y or N )==> Appro xima te Sha piro -Fra ncia Norm ality Tes t EU Metho d II Dist ribu tion -Free Cali forn ia M ethod μ + 3 σClopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 16 of 19 Bushberry subgroup 13 - 07B . The dataset used to establish a tolerance for clop yralid on the bushberry subgroup 13 - 07B consisted of field trial data on blueberries at application rates of 0.483 - 0.525 lb a e/A (2 applications at 0.240 - 0.264 lb a e/A) with a 27 - 33 day PHI . As specified by

the SOP, the field trial application rates and PHI s are within 25% of the maximum label application rate and minimum label PHI , respectivel y. The residue values used to calculate the tolerance are provided in Table II - 2. Residues from the foliar application trial are not included in the dataset. The blueberry

dataset is relatively

large (14 samples). The dataset was entered into the tolerance spreadsheet. The approximate Shapiro - Francia test statistic (Figure II - 4) indicates that the assumption of lognormality should be rejected and visual inspection of the lognormal probability plot for blueberry

(Figure II - 3) provided in the spreadsheet supp orts that conclusion. Therefore, the recommended tolerance on the bushberry subgroup 13 - 07B is 0.50 ppm. Table II - 2. Residue data used to calculate tolerance for Clopyralid on Blueberry. Regulator: EPA Chemical: Clopyralid Crop: Blueberry PHI: 27 - 33 Days App. Rate: 2 applications at 0.240 - 0.264 lb ae/A Submitter: IR- 4 MRID Citation: MRID 47 604402 Residues 0.05 0.05 0.05 0.05 0.05 0.05 0.056 0.057 0.064 0.095 0.16 0.22 0.34 0.42Clopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 17 of 19 Figure II - 3. Lognorm al probability plot of Clopyralid field trial data for Blueberry. Lognormal Probability Plot

99.9 99 98 95 90 80 70 50 30 20 10 5 2 1 0.1 1.0000

0.5000

0.2500

0.1250

0.0625

0.0313 y = 0.7123x - 2.4369 R 2 = 0.7594

PercentilesConcentrations EPA Clopyralid Blueberry 27-33

Figure II - 4. Tolerance spreadsheet summary of Clopyralid field trial data for Blueberry. Re gu la to r: EP A Ch em ic al : Cl op yr al id Cr op : Bl ue be rr y PH I: 27 -3 3 Ap p. R ate: Su bmit te r: n: 14 mi n: 0.0 5 max: 0.4 2 me di an : 0.0 6 av er age: 0.1 2 95 th Per ce nt il e 99 th P er ce nt il e 99 .9 th P er ce nt il e 0. 35 0.4 5 0. 50 (0 .4 5) (0 .6 0) (- -) 0. 35 0.6 0 1. 0 (0 .7 0) (1 .5 ) (- -) 0.3 5 0.5 0 0.3 5 0. 75 94 p- va lu e <=0 .0 1: R ej ec t lo gn or mal it y as su mp ti on

Wou ld y ou l ik e th e a bo ve v al ue s rou nd ed ? (Y o r N) ==> Y App ro xi ma te Sh api ro -F ra nc ia No rm al it y Tes t EU Me th odI No rm al

UCLM ed ia n9 5t h 95 /9 9 Ru le EU M et ho d II Di stri bu ti on -F re e Me an+3 SDClopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 18 of 19 Strawberry (grown in an annual production strategy; FL and NC only) The dataset used to establish a tolerance for clop yralid on strawberry consisted of field trial data representing a single application at rates of 0.246 - 0.255 lb ae/A with a 7 - 8 day PHI . As specified by the SOP, the field trial application rates and PHIs are within 25% of the maximum label application rate and minimum label PHI , respectively . The residue values used to calculate the tolerance are provided in Table II - 3. All field trial sample results for strawberry were above the LOQ (0.05 ppm ). The strawberry dataset was small (6 samples). The dataset was entered into the tolerance spreadsheet. Visual inspection of the lognormal probability plot for strawberry

(FigureII - 5 ) provided in the spreadsheet indicate d that the dataset was reasonably lognormal . The result from the approximate Shapiro - Francia test statistic (Figure II - 6 ) confirmed that the assumption of lognormality should not be rejected for strawberry . Using the tolerance spreadsheet, the recommended tolerance is 4.0 ppm on strawberries . T able II - 3. Residue data used to calculate tolerance for Clopyralid on Strawberry. Regulator: EPA Chemical: Clopyralid Crop: Straw berry (annual, grown only in FL) PHI: 7 - 8 Days App. Rate: 1 application at 0.246 - 0.255 lb ae/A Submitter: IR- 4 MRID Cita tion: MRID 4 7604403 Residues 1.6 2 .0 2.1 2.7 2.7 3 .0Clopyralid Summary of Analytical Chemistry and Residue Data DP#: 361787

Page 19 of 19 Figure II - 5. Lognorm al probability plot of Clopyralid field trial data for Strawberry. Lognormal Probability Plot

99.9 99 98 95 90 80 70 50 30 20 10 5 2 1 0.1 3.0000

1.5000 y = 0.2502x + 0.8317 R 2 = 0.9327

PercentilesConcentrations EPA Clopyralid Strawberry 7-8 Days 1 at 0.246-0.255 lb ai/A IR-4 MRID 47604403

Figure II - 6. Tolerance spreadsheet summary of Clopyralid field trial data for Strawberry. Regu lator : EP A Che mical : Cl opyra lid Crop : St rawbe rry PHI : 7- 8 Da ys App. Rate :

1 at 0.24 6-0.2 55 l b ai/ A Subm itter : IR-4 MRID Cit ation : MRI D 476 0440 3

n: 6 min : 1.60 max : 3.00 me dian ; 2.40 av erage : 2.35 95th Perc enti le 99t h Pe rcent ile 99 .9th Perc enti le 3.5 4. 0 4.0 (4.5 ) (6 .0) (- -) 3.5 4. 0 5.0 (6.0 ) (8 .0) (- -) 6. 0 4. 0 UP LMe dian9 5th 30 0.932 7 p- value > 0 .05 : Do not rejec t lo gnorm alit y as sumpt ion

Y EU Me thod I Norma l EU Me thod I Lo g Nor mal

Wou ld y ou l ike t he a bove valu es rou nded ? (Y or N )==> Appro xima te Sha piro -Fra ncia Norm ality Tes t EU Metho d II Dist ribu tion -Free Cali forn ia M ethod μ + 3 σ