Glyphosate Summary of Analytical Chemistry and Residue Data DP#: 394964

page 2 of 15 

### Executive Summary Background: Glyphosate is a nonselective Group 9 herbicide that disrupts the synthesis of the aromatic amino acids tyrosine, tryptophan, and phenylalanine through inhibition of 5

- enolpyruvylshikimate

- 3

- phosphate synthase (EPSPS). Glyphosate is currently registered for pre

and post

- emergence application to a variety of fruit, vegetable, and field crops. Tolerances are currently established for residues of glyphosate in/on various plant commodities at 0.2

- 400 ppm (40 CFR §180.364(a) (1) ; canola seed at 20 ppm) and for the combined residues of glyphosate and N

- acetyl

- glyphosate (expressed in glyphosate equivalents) in/on field corn, soybean, aspirated grain fr actions ( AGF ) , and livestock commodities at 0.1 0

- 310 ppm (40 CFR §180.364(a)(2))

. The g lyphosate Reregistration Eligibility Decision (RED) document was issued September 1993

. A Registration Review Scoping document was completed in 2009 (D362745, J. Langs dale et al ., 3

- Jun

- 2009). The current proposal concerns application of glyphosate to the glyphosate

- tolerance canola variety DuPont TM Optimum® GLY Canola (also called canola ( Event DP

- Ø 73496

- 4))

. The petitioner indicated that Optimum ® 

### GLY Canola has been genetically modified to express the gat 4621 gene derived from the soil bacterium Bacillus licheniformis (e

- mail from DuPont ; Tim McPherson; 21

- Oct

- 2011; 10:07 am). The protein encoded by the gat 4621 gene confers tolerance to glyphosate via acety lation of the secondary amine group of glyphosate resulting in the formation of the non

- herbicidal N

- acetyl

- glyphosate. Proposed Use: The petitioner submitted a proposed supplemental label for DuPont TM AbunditTM S Herbicide (EPA Reg. No. 352

- 832 ; water s oluble liquid; i sopropylamine s alt of g lyphosate ; 3 lb ae/gal) which includes directions for application to DuPont TM Optimum® GLY Canola. Table 3 is a summary of the proposed end

- use product and Table 4 is a summary of the proposed application scenario. Based on the currently available confined/field rotational crop data, a 30

- day plant

- back interval ( PBI ) for all non
- labeled crops is appropriate following application to Optimum® GLY canola . A revised Section B is requested. Nature of the Residue

– P rimary Crops : Metabolism studies conducted with non

- transgenic corn, cotton, soybeans, and wheat were previously submitted and reviewed. Based on these data, HED concluded that the residue of concern in non

- transgenic plants is glyphosate (Memo, R. Perfetti, 19

- Oct

- 1992; RED, R. Perfetti, 27

- Oct

- 1992; Memo, R. Perfetti, 17

- Mar

- 1994). Metabolism studies have also been submitted o n glyphosate

- tolerant canola ( RT73; D242628, T. Bloem, 30

- Nov

- 1998) and glyphosate

- tolerant field corn ( Roundup Ready ® 

### field corn; D217539, G. Kramer, 14

- Mar

- 1996). The glyphosate

- tolerant canola and field corn varieties were genetically modified to expre ss the EPSPS gene derived from Agrobacterium sp. (strain CP4) which codes for an EPSPS protein that is not inhibited by glyphosate . The glyphosate

- tolerant canola and corn were also genetically engineered to express the oxireductase gene which converts glyphosate to the non

- herbicidal AMPA (aminomethyl phosphonic acid) . Metabolism in these varieties of transgenic canola and corn was essentially the same as the non

- transgenic plants. Therefore, it was concluded that the terminal res idue to be regulated, in non

- transgenic plants and transgenic field corn and canola modified to express the Agrobacterium sp. EPSPS and oxireductase genes, is glyphosate. Subsequent to the s e decision s , HED approved DuPont requests permitting the commercia lizationGlyphosate Summary of Analytical Chemistry and Residue Data DP#: 394964

page 3 of 15 

### of Optimum GAT soybean and Optimum GAT field corn (D346713, T. Bloem, 12

- Mar

2008; D357880, T. Bloem, 29

- Oct

- 2008; D361315, T. Bloem, 14

- Jan

- 2010). Optimum GAT soybean was engineered to express the gat 4601 gene ( derived from Bacillus lichen iformis ; soil bacterium) and Optimum GAT field corn was engineered to express the gat 4621 gene ( derived from Bacillus licheniformis ) and the zm - hra gene (modified version of maize acetolactate synthase (ALS) gene). The protein encoded by the gat 4601 and the gat

4621 genes confer tolerance to glyphosate via acetylation of the secon dary amine group of glyphosate result ing in the formation of the non

- herbicidal N

- acetyl

- glyphosate; the zm - hra gene in Optimum GAT field corn, encodes for an ALS prote in which is not sensitive to the ALS

inhibiting herbicides. As a result of the introduction of these seed lines, HED concluded that the residues of concern in plants for tolerance expression and risk assessment should change from glyphosate to the combine d residues of glyphosate and N

- acetyl

- glyphosate (expressed in glyphosate equivalents; D346713, T. Bloem, 12

- Mar

- 2008). Subsequent to this decision, it was determined that only the tolerance expression for field corn and soybean would change from glyphosa te to the combined residues of glyphosate and N

- acetyl

- glyphosate (expressed in glyphosate equivalents) ; the tolerance expression for all other crops would remain as glyphosate. The current action is requesting application of glyphosate to Optimum ® 

### GLY Canola (also called canola ( Event DP

- Ø 73496

- 4)). Optimum ® 

### GLY Canola is a new variety of canola genetically modified to express the gat 4621 gene derived from the soil bacterium Bacillus licheniformis (e

mail from DuPont ; Tim McPherson; 21

- Oct

- 2011; 1 0:07 am). The protein encoded by the gat 4621 gene confers tolerance to glyphosate via acetylation of the secondary amine group of glyphosate resulting in the formation of the non

- herbicidal N

- acetyl

- glyphosate. Based on the results of a metabolism study conducted with canola genetically modified to exp ress the microbial gat gene (preemergence and foliar applications) and previous conclusion s pertaining to the toxicity of AMPA ( Memo, R. Perfetti, 17

- Mar

- 1994 ) and N

- acetyl

- AMPA (D345926, T. Bloem et al. , 18

- Mar

- 2008) , HED concludes that with the introduction of Optimum ® 

### GLY Canola the residues of concern in canola , for tolerance expression and risk assessment purposes , are glyphosate and N

- acetyl

- glyphosate (expressed in glyphosate equivalents)

. Nature of the Residue
- Livestock: The qualitative nature of the residue in livestock following dosing with glyphosate and AMPA is adequately understood. Studies with lactating goats and laying hens fed a mixture of glyphosate and AMPA indicate that the primary route of elimination was by excretion (urine and feces). HED determined that the terminal residue to be regulated in livestock is glyphosate (Memo, R. Perfetti, 19

- Oct

- 1992; RED, R. Perfetti, 27

- Oct

- 1992; Memo, R. Perfetti, 17

- Mar

- 1994).
DuPont previously submitted summaries of in vitro (rumen fluid, fertile hen egg, and rat liver S9 supernatant) and in vivo (rat , goat, and hen metabolism stud ies ) studies conducted with the N

acetyl

- glyphosate metabolite. Based on these data and the glyphosate metabolism studies , HED concluded that the residues of concern in livestock following consumption of glyphosate and N

acetyl

- glyphosate , for tolerance expression and risk assessment purposes, are glyphosate and N

acetyl

- glyphosate ( expr essed in glyphosate equivalents; D346713, T. Bloem, 12

- Mar

- 2008; D361315, T. Bloem, 14

- Jan

- 2010)

. Based on these data and since Optimum ® 

### GLY Canola do es not result in any addition metabolites, HED concludes that the previous decisions concerning the resid ues of concern in livestock remain appropriate.Glyphosate Summary of Analytical Chemistry and Residue Data DP#: 394964

page 4 of 15 

### Magnitude of the Residue
- C anola : A tolerance for residues of glyphosate per se in/on canola seed at 20 ppm is currently established. The submitted field trials conducted with canola ( Event DP

- Ø 73496

- 4) are considered adequate to support the proposed application scenario and resulted in combined glyphosate and N

- acetyl

- glyphosate (expressed in glyphosate equivalents) residues in/on seed of ≤2.0 ppm (no additional field trial data are required). In addition, an adequate canola seed processing study was submitted which indicates that combined residues of glyphosate and N

- acetyl

- glyphosate do not concentrate in canola meal (≤1.1x) or oil (<0.005x).
B ased on the available data, HED agrees with the petitioner’s proposal to mo ve the currently

established 20

- ppm canola seed tolerance from 180.364(a)(1) where the tolerance expression is for residues of only glyphosate to 180.364(a)(2) where the tolerance e xpression is for combined residues of glyphosate and N

- acetyl

- glyphosate (expressed in glyphosate equivalents). Magnitude of the Residue
- Livestock : The current petition results only in a change to the canola seed glyphosate tolerance expression (tole rance values are not changing) . Therefore, the currently

- established livestock tolerances remain appropriate.
Nature/ Magnitude of the Residue
- Rotational Crops : Based on previously

- reviewed confined rotational crop studies (3.71 lb ae/acre (2.2x) ; MR IDs 41543201 and 41543202, A. Abramovitch, 14

- Oct

- 1992) which resulted in glyphosate residues of >0.01 ppm in barley grain only (0.018 ppm; 125

- day PBI) and the limit of quantitation ( LOQ ) for the tolerance enforcement method of 0.05 ppm, HED previously concluded that a 30

- day PBI was appropriate for all non

- labeled crops (D200041, G. Kramer, 12

- May

- 1994; field rotational crop study has not been submitted). B ased on the LOQ for the tolerance

- enforcement method and since the confined rotational crop study employed an exaggerated rate to bare soil, a 30

- day PBI for all non

- labeled crops is acceptable following application to Optimum® GLY canola . A revised Section B is requested. Analytical Enforcement Method: DuPont liquid chromatography/mass spectrome try/mass spectrometry ( LC/MS/MS ) Methods 15444 ( corn and soybean ) and 20009 (livestock) have been determined to be acceptable for enforcement of the current tolerances for the combined residues of glyphosate and N

- acetyl

- glyphosate in/on field corn, soybea n, and livestock and these methods were forwarded to the Food and Drug Administration ( FDA ; D357880, T. Bloem, 29

- Oct

- 2008; D361315, T. Bloem, 14

- Jan

- 2010). The canola field trial and processing studies submitted as part of the current petition were analy zed for residues of glyphosate, N

- acetyl

- glyphosate, AMPA, and N

- acetyl AMPA using the DuPont LC/MS/MS Method 15444. Since adequate validation data were submitted as part of the canola field trail and processing data, HED concludes that DuPont LC/MS/MS Me thod 15444 is appropriate for data collection and enforcement purposes for canola.
Recommendations: Provided the petitioner submits a revised Section B specifying a 30

- day PBI for all non

- labeled crops following application to Optimum® GLY canola , HED concludes that the residue chemistry database supports an unconditional registration for the proposed application scenario

. A human

- health risk assessment will be prepared as a separate document (D387535)

.Glyphosate Summary of Analytical Chemistry and Residue Data DP#: 394964

page 5 of 15 

### Background Glyphosate is a nonselective Group 9 herbicide which disrupts the synthesis of the aromatic amino acids tyrosine, tryptophan, and phenylalanine through inhibition of EPSPS. Glyphosate is currently registered for pre

- and post

- emergence application to a variety of fruit, vegetable, and fiel d crops. Tolerances are currently established for residues of glyphosate in/on various plant commodities at 0.2

- 400 ppm (40 CFR §180.364(a) (1) ) and for the combined residues of glyphosate and N

- acetyl

- glyphosate (expressed in glyphosate equivalents) in/on field corn, soybean, AGF, and livestock commodities at 0. 1

- 310 ppm (40 CFR §180.364(a)(2)) . The g lyphosate RED document was issued September 1993. A Registration Review Scoping document was completed in 2009 (D362745, J. Langsdale et al ., 3

- Jun

- 2009). T he chemical structure / nomenclature and physicochemical propertie s of glyphosate are presented in Tables 1 and 2 , respectively

.
T able 1 : Glyphosate Nomenclature.

Compound

Common name Glyphosate (PC code 471300) Company experimental name DPX

- B2856 IUPAC /CAS name N

- (phosphonomethyl)glycine CAS registry number 1071

- 83

- 6

T able 2 : Physicochemical Properties of Technical Grade Glyphosate. Melting point 189.5 ± 0.5 °C The Pesticide Manual, 13 th Edition pH 1.9 at 20 °C Density 1.705 g/cm 3 at 20 °C Water solubility 10.5 g/L at 20 °C

Solvent solubility acetone 0.078 g/L methanol 0.231 g/L hexane 0.026 g/L ethyl acetate 0.012 g/L dichloromethane 0.233 g/L n
- octanol 0.020 g/L propan
- 2

- ol 0.020 g/L toluene 0.036 g/L European Commission: Glyphosate 6511/VI/99

- final, 1/21/02

Vapor pressure 1.31 x 10 - 2 mPa at 25 °C The Pesticide Manual, 13 th Edition Dissociation constant, pK a 0.8 (1 st phosphoric), 2.3 (carboxylate), 6.0 (2 nd phosphoric), and 11.0 (amine) Knuuttila. 1979 Acta Chem. Scand. B 33:623

- 626 Octanol/water partition coefficient, Log(K OW )

- 3.2 (pH 2

- 5, 25 °C ) European Commission: Glyphosate 6511/VI/99

- final, 1/21/02 UV/visible absorption spectrum ε = 0.086 (295nm)Glyphosate Summary of Analytical Chemistry and Residue Data DP#: 394964

page 6 of 15 

### 860.1200 Directions for Use The petitioner submitted a proposed supplemental label for DuPont TM AbunditTM S Herbicide (EPA Reg. No. 352

- 832) which include s directions for application to DuPont TM O ptimum ® GLY C anola. T able 3 is a summary of the proposed end

- use product and Table 4 is a summary of the proposed application scenario. Based on the currently available confined/field rotational crop data, a 30

- day PBI for all non

- labeled crops is appropriate following application to Optimum® GLY canola . A revised Section B is requested.

T able 3 : Summary of Proposed End
- Use Products. Trade Name EPA Reg. No. concentration Form

. Label Date Target Crops Target Pests DuPont TM AbunditTM S Herbicide 352

- 832 glyphosate as the isopropylamine salt 4 lb ai/gal (3 lb ae/gal) water

soluble liquid not indicated DuPont TM

Optimum® GLY Canola numerous annual and

perennial grasses and broadleaf weeds

Table 4 : Summary of Proposed Application Scenario for DuPont TM Optimum® GLY Canola
. 1 Formulation (EPA Reg. No.) App. Timing App. Rate (lb ae/acre) Max. App.

Rate (lb ae/acre) Use Directions and Limitations

DuPont TM AbunditTM S Herbicide (EPA Reg. No. 352

- 832) broadcast preplant

or preemergence not specified 1.125 - No more tha n two post

- emergent over

- the

- top applications may be made from crop emergence to the 6

- leaf stage (minimum retreatment interval of 10 days).

- Applications may be made with ground (3

- 40 gallons per acre ( GPA ) ) or aerial (3

- 15 GPA) equipment.

- The last applic ation must be made at least 60 days before harvest.

- The main label indicates that there are no rotational crop restrictions following application of this product.

- The main label indicates that addition of ammonium sulfate may increase product performance (17 lbs/100 gallon). emergence through 6

- leaf stage 0.234

- 0.398 0.562

1 The proposed product is not currently registered for application to canola. HED recently recommended in favor of a petition concerning the application of Roundup WeatherMAX ® (EPA Reg. No. 524

- 537) and Roundup PowerMAX ® (EPA Reg. No. 524

- 549) to Roundup Ready ® Flex Canola (D394004, T. Bloem, 15

- Sep

- 2011)

. 

### 860.1300 Nature of the Residue
- Plants and Livestock (48398601.der) 

### In support of the current proposal, the petitioner submitted a metabolism study conducted with a canola variety genetically modified to express the microbial glyphosate N

- acetyltransferase ( gat ) gene (0827 canola; 48398601.de r). A summary of the study is presented below. See t he Executive Summary for information detailing HED’s conclusions pertaining to the residues of concern in plants and livestock.
48398601.der: The canola variety used in the study (0827 canola) was gen etically modified to express the microbial glyphosate N

- acetyltransferase ( gat ) gene which confers tolerance to glyphosate via acetylation of the secondary amine group of glyphosate resulting in the formation of the non

- herbicidal N

- acetyl

- glyphosate . R adiolabeled glyphosate was applied as a preemergence soil application at a rate of 4.02 lb ae/acre, followed by three foliar applications at 0.84

- 0.91 lb ae/acre/application for a total application rate of 6.65 lb ae/ acre (greenhouse grown)

. Foliar applic ations were started 21 days after the soil application, and were made at the BBCH 12, 15 , and 87 growth stages, with 14

- and 90

- day RTIs. Samples of immature foliage (BBCH 69) were collected 38 days after the second foliar application (midway between the second andGlyphosate Summary of Analytical Chemistry and Residue Data DP#: 394964

page 7 of 15 

### third foliar application), preharvest foliage and pods with seed (BBCH 87) were collected 90 days after the second foliar application (immediately prior to the third foliar application), and mature seed (BBCH 89) was collected 7 days after the l ast foliar application. Table 5 is a summary of the total radioactive residues ( TRR s) and a summary of the identified/characterized residues. Glyphosate was a major residue in mature seed (20.8% TRR, 0.448 ppm), but was identified at a much lower level i n immature foliage (3.0% TRR, 0.179 ppm), and was not identified in preharvest foliage or pods (with seed). The major residue in all matrices was N

- acetyl

- glyphosate at 89.5% TRR (5.351 ppm) in immature foliage, 93.0% TRR (1.442 ppm) in preharvest foliage , 79.6% (1.013 ppm) in preharvest pods (with seed), and 51.1% TRR (1.101 ppm) in mature seed. N

- acetyl AMPA was also a major residue in mature seed (14.7% TRR, 0.316 ppm) and was identified at a lower level in immature foliage (3.4% TRR, 0.203 ppm). AMPA was a minor metabolite in immature foliage and mature seed at 1.4% and 1.9% TRR, respectively. In mature seed, unidentified metabolites accounted for a total of 7.1% TRR (0.152 ppm), with no individual metabolite exceeding 1.0% TRR (0.022 ppm).
Based on the results of the metabolism study, the petitioner propose d that glyphosate is acetylated in 0827 canola plants to form N

- acetyl

- glyphosate

. N

- a cetyl

- glyphosate and glyphosate are further metabolized to N

- acetyl AMPA. Low levels of AMPA detected in can ola fractions (foliage and mature seed) could result, in part, from low levels of [ 14 

### C]AMPA in the treatment solutions or from glyphosate or N

- acetyl AMPA metabolism in the plant.

T able 5: S ummary of Characterization and Identification of Radioactive Res idues
.

Metabolite Fraction Immature Foliage Preharvest Foliage Preharvest Pods (with Seed) Mature Seed
TRR = 5.979 ppm TRR = 1.550 ppm TRR = 1.273 ppm TRR = 2.155 ppm %TRR ppm %TRR ppm %TRR ppm %TRR ppm Glyphosate 3.0 0.179

-- -- -- -- 20.8 0.448 AMPA 1.4 0.084

-- -- -- -- 1.9 0.041 N

- Acetyl AMPA 3.4 0.203

-- -- -- -- 14.7 0.316 N

- Acetyl

- glyphosate 89.5 5.351 93.0 1.442 79.6 1.01 3 51.1 1.10 1 Unidentified

-- -- -- -- -- -- 7.1 0.1 5 2 Amylase hydrolysate

-- -- 1.7 0.0 26

-- -- 11.7 0.252 Amyloglucosidase/ cellulose hydrolysate

-- -- 0.5 0.0 08

-- -- 2.3 0.050 Base hydrolysate

-- -- 0.8 0.012

-- -- 3.2 0.069 Acid hydrolysate

-- -- 0.4 0.006

-- -- 0.9 0.019 Total identified 97.3 5.8 17 93.0 1.44 2 79.6 1.01 3 88.5 1.906 Unidentified residues from HPLC analysis

-- -- -- -- -- -- 7.1 4 0.152 4 Total extractable 1 97.3 5.8 18 9 3.0 1. 442 79.6 1.01 3 78.4 1.690 Total hydrolyzed 2

-- -- 3.4 0.05 2

-- -- 18.1 0.390 Unextractable (PES) 3 2.7 0.16 1 3.6 0.0 5 6 20.4 0.26 0 3.5 0.0 75 Accountability 100 100 100 100 1 1% formic acid:methanol; 96:4; v:v. 2 Combined amylase, a myloglucosidase/cellulase , b ase , and acid hydrolysate s. Only the preharvest foliage and mature seed were hydrolyzed and only the mature seed hydrolysates were HPLC analyzed (glyphosate: 1.6% TRR; AMPA: 1.9% TRR; N

- acetyl

AMPA: 0.4% TRR; N

- acetyl

- glyphosate: 6.3% TRR). 3 Residues remaining after exhaust ive extractions. 4 N o individual unidentified residue exceed ed 1.0% TRR (0.022 ppm).Glyphosate Summary of Analytical Chemistry and Residue Data DP#: 394964

page 8 of 15 

### 860.1340 Residue Analytical Methods
DuPont LC/MS/MS Methods 15444 ( corn and soybean ) and 20009 (livestock) have been determined to be acceptable for enforcement of the current tolerances for the combined residues of glyphosate and N

- acetyl

- glyphosate in/on field corn, soybean, and livestock and these methods were forwarded to FDA ( D35788 0 , T. Bloem, 29

- Oct

- 2008; D361315, T. Bloem, 14

- Jan

- 2010 ). The canola field trial and processing studies submitted as part of the current petition were analyzed for residues of glyphosate, N

- acetyl

- glyphosate, AMPA, and N

- acetyl AMPA using the DuPont Meth od 15444. Since adequate validation data were submitted as part of the canola field trail and processing data, HED concludes that DuPont Method 15444 is appropriate for data collection and enforcement purposes for canola. Standards and fortification solu tions were prepared for the analytes in glyphosate equivalents, and all residues were quantitated as glyphosate equivalents. The method LOQ (determined as the lowest level of method validation ( LLMV ) ) was 0.05 ppm for each analyte/matrix; the limit of det ection ( LOD ) was defined as 0.02 ppm (1/3 LOQ). Residues in/on controls were generally <LOD and/or insignificant when compared to residues in/on the treated samples. The study indicated that concurrent recoveries were corrected for apparent residues ≥0.0 1 ppm in control samples (treat ed samples were not corrected).
8 60.1360 FDA Multiresidue Methods (MRMs) Protocols The FDA Pestrak database (1990) indicate that recoveries are not likely for glyphosate under the FDA MRMs. Data concerning the behavior of N

- acetyl

- glyphosate under the FDA MRMs has also been previously provided (47133201.der.doc). Using Protocol A, N

- acetyl

- glyphosate was determined not to be naturally fluorescent. Using Protocols B and C, derivatized (methylated) and underivatized N

- acety l

- glyphosate were tested using the nitrogen

- specific Modules DG5 (DB

- 1 column) and DG17 (DB

- 17 column) which employ a nitrogen

- phosphorus detector (NPD) and the more general Module DG18 (DB

- 225 column) which employs an electron

- capture detector (ECD). N

- acetyl

- glyphosate was not chromatographable using DB

- 1, DB

- 17, or DB

- 225 columns with NPD or ECD; therefore, no testing was performed under Protocols D, E, or F. Because the test substance is not a substituted urea, no testing under Protocol G is require d. The results indicate that the MRMs are not suitable for the determination of N

- acetyl

- glyphosate. These data were forwarded to FDA (D349698, T. Bloem, 5

- Mar

- 2008). 860.1380 Storage Stability (48398603.der) 

### The canola commodities from the field trial and processing studies were stored frozen for the following durations: 302 days for forage, 293 days for seed, 53 days for meal, and 46 days for oil. Extracts were stored for up to 108 days prior to analysis. Storage stability data are available which indicate that residues of glyphosate, N

- acetyl

- glyphosate, and AMPA are stable for up to 12 months and residues of N

- acetyl AMPA are stable for up to18 months in/on DP

- 356Ø43

- 5 soybean forage, seed, and hay ( ~ - 20 °C ; 48398603.der). DP

- 356Ø43

- 5 soybean is soybean genetically modified to express the microbial glyphosate N

- acetyltransferase (GAT) gene ( gat 4601) and the gm - hra gene which confers tolerance to ALS inhibiting herbicides. Based on these data and since the extracts for the concurrent recovery sam ples were stored for the same intervals as the extracts for the treated samples and acceptable recoveries were attained, the storage intervals for the extracts and RACs have been validated. Although storage stability data are not available for the process ed commodities, HED will not require additional storage stability data for meal and oil in consideration of the physical similarities between canola meal and seed and the relatively short storage duration for oil.Glyphosate Summary of Analytical Chemistry and Residue Data DP#: 394964

page 9 of 15 

### 860.1480 Meat, Milk, Poultry, and Eggs Th e current petition results only in a change to the canola seed glyphosate tolerance expression (tolerance values are not changing) . Therefore, the currently

- established livestock tolerances remain appropriate. 860.1500 Crop Field Trials ( 483 98602 .der 1 ) 

### Canola field t rials were conducted during the 2009 growing season in Canada and the U.S. reflecting different use patterns for the two countries. Ten trials were conducted using the Canadian application scenario in the North American Free Trade Agreemen t (NAFTA) Growing Zones 5 ( n=1 ), 7 ( n= 2 ), and 14 ( n= 7 ) and six trials were conducted using the U.S. application scenario in Zones 2 ( n= 1), 5 ( n= 1 ), 7 ( n=2 ), and 11 ( n= 2 ). HED notes that these figure s incorporate a reduction in the number of the trails con duct e d in Zone 14 (14 to 7 ; Canadian application scenario ) and 11 ( 3 to 2; U.S. application scenario ) due to classification of trials conducted at the same location as replicates and incorporates a reduction in the number of trials conducted in Zone 5 (2 to 1; U.S. application scenario) due elimination of trial as a result of overspray from a neighboring field

. At each field trial location, canola ( Event DP

- Ø 73496

- 4) was planted and treated with the 4.17 lb ae/gal soluble soluble

- concentrate/liquid (SL/L) formulation of the potassium salt of glyphosate (Touchdown® Total herbicide; EPA Reg. No. 100

- 1169)

. Table 6 is a summary of the Canadian and U.S. application scenarios. For the C anadian field trials, white mesh tents were used to cover the field plots. The tents reflected some light, resulting in plants that were taller and thinner than normal. The tents also created a warmer, more humid environment, which prolonged flowering an d delayed maturity beyond that for normal un

- tented plants. The study indicated that consequently: the trials ran late into the season; it was harder to determine staging and timing; and in some provinces, the crops were affected by frost before sampling occurred. Canola forage samples were harvested from the Canadian and U.S. trials at the earliest forage stage but not befo re 60 days after planting. Forage preharvest intervals ( PHIs ) were 35

- 82 days for the Canadian trials and 27

- 55 days for the U.S. trials (interval after the second application for both the Canadian and U.S. trials) . Mature canola seed was harvested 6

- 8 days following the third application in the Canadian trials, and 55

- 77 days following the second application in the U.S. trials. I n some trials, seed was allowed to dry in the field for 3

- 13 days prior to collection. Residue decline samples were also collected at one of the Canadian U.S. trials

. The harvested samples were analyzed for residues of glyphosate, N

- acetyl

- glyphosate, AMPA, and N

- acetyl AMPA using the DuPont TM HPLC/MS/MS method 15444 (all residues were quantitated in glyphosate equivalents). The method was adequately validated and is appropriate for data collection (storage interval has also been vali dated). Based on the LLMV, the LOQ is 0.05 ppm for analyte/matrices. Table 7 is a summary of the residues

. The residue decline trial conducted using the Canadian application scenario indicated the following: (1) forage

- residues of N

- acetyl

- glyphosa te showed a slight decrease as the PHI increased (residues of glyphosate, AMPA, and N

- acetyl

- AMPA were <LOQ) and (2) seed

- residues of glyphosate increased and residues of N

- acetyl

- glyphosate were consistent as the PHI increased (combined glyphosate and N

- acetyl

- glyphosate showed an increase as the PHI increased; residues of AMPA and N

- acetyl

- AMPA were <LOQ).Glyphosate Summary of Analytical Chemistry and Residue Data DP#: 394964

page 10 of 15 

### The residue decline trial conducted using the U.S. application scenario indicated the following: (1) forage

- residues of N

- acetyl

- glyphosate incr eased as the PHI increased (residues of glyphosate, AMPA, and N

- acetyl

- AMPA were <LOQ) and (2) seed

- residues of N

- acetyl

glyphosate were consistent as the PHI increased (residues of glyphosate, AMPA and N

- acetyl

AMPA were <LOQ).
Conclusions: A tolera nce for residues of glyphosate per se in/on canola seed at 20 ppm is currently established (HED does not consider canola forage to be a food/feed commodity). The submitted field trial data resulted in combined glyphosate and N

- acetyl

- glyphosate residues i n/on seed of ≤2.0 ppm f

ollowing treatment at 1.3x the proposed maximum seasonal application rate (PHI = 55

- 77 days ; glyphosate and N

- acetyl

- glyphosate are the residues of concern in DuPont TM Optimum® GLY Canola)

. To fulfill the geographical data requirements specified in OPPTS 860.1500, additional canola field trials in NAFTA Growing Zones 5 (n=1) and 11 (n= 1 ) are required. Since combined residues of glyphosate and N

- acetyl

- glyphosate residues were less than the c urre ntly established tolerance even under the higher rates associated with Canadian application scenario, HED concludes that no additional field trial data are required. Based on the available data and the revisions to the canola seed tolerance expression as a result of the introduction of DuPont TM Optimum® GLY Canola, HED concludes that the currently

established 20 ppm canola seed tolerance should be deleted from 180.364(a)(1) and established in 180.364(a)(2).

Table 6 : Summary of Application Scenarios.

n 1 lb ae/acre (kg ae/ha) preemergence 6

- leaf stage (foliar) 7

- days before harvest (foliar) total Canadian Application Sceario 1 10 0.59

- 0.62 (0.66

- 0.70) 0.59

- 0.62

(0.66

- 0.70) 0.78

- 0.83

(0.88

- 0.93) 3 forage

- 1.18

- 1.24 (1.32

- 1.40) 4

seed

- 1.99

- 2.26 (2.23

- 2.53) 4 U.S. Application Scenario 2 6 1.55

- 1.60 (1.73

- 1.80) 0.56

- 0.57

(0.62

- 0.64) -- forage and seed

- 2.11

- 2.17 (2.36

- 2.43)
1 R TIs were 30

- 50 days between the first and second applications and 72

- 93 days between the second and third applications. All a pplications were made in spray volumes of 5.3

- 10.7 GPA ( 50

- 100 L/ha). An adjuvant was not added to the spray mixture for any application. 2 R TIs were 20

- 34 days, and applications were made in spray volumes of 5

- 30 GPA (47

- 281 L/ha). Ammonium sulfat e fertilizer was added to the tank mixtures at ~10

- 17 lb/100 gal. 3 One trial had a final application rate of 1.06 lb ae/acre (1.193 kg ae/ha); this trial did not result in the maximum residues

. 4 Forage harvested after the 6

- leaf stage application and prior to the final application; seed harvested after the final application.Glyphosate Summary of Analytical Chemistry and Residue Data DP#: 394964

page 11 of 15 T able 7 : S ummary of Residue Data from DP
- Ø73496

- 4 Canola Crop Field Trials with Glyphosate.

Com m. Total App. Rate ,

lb a e / acre (kg ae/ha) PHI

(days) Residue Level s, Glyphosate Equivalents (ppm) 1

n Sample Min. Sample

Max. L AFT HAFT Median Mean Std. Dev. Canadian Trials 2 Glyphosate Forage 1.18

- 1.28 (1.32

- 1.44) 35

- 82 10 <0.05 0.26 0.05 0.11 0.05 0.06 0.02 Seed 1.99

- 2.26 (2.23

- 2.53) 6

- 8 10 0.29 9.9 0.44 9.0 1.7 2.7 2.7 N
- acetyl
- glyphosate Forage 1.18

- 1.28 (1.32

- 1.44) 35

- 82 10 <0.05 1.1 0.08 0.81 0.26 0.31 0.23 Seed 1.99

- 2.26 (2.23

- 2.53) 6

- 8 10 0.17 14 0.18 12 0.35 1.7 3.5 AMPA Forage 1.18

- 1.28 (1.32

- 1.44) 35

- 82 10 <0.05 0.07 0.05 0.06 0.05 0.05 <0.01 Seed 1.99

- 2.26 (2.23

- 2.53) 6

- 8 10 <0.05 0.09 0.05 0.07 0.05 0.05 0.01 N
- acetyl AMPA Forage 1.18

- 1.28 (1.32

- 1.44) 35

- 82 10 <0.05 <0.05 0.05 0.05 0.05 0.05 NA Seed 1.99

- 2.26 (2.23

- 2.53) 6

- 8 10 <0.05 0.35 0.05 0.34 0.05 0.08 0.09 Combined glyphosate and N
- acetyl
- glyphosate Forage 1.18

- 1.28 (1.32

- 1.44) 35

- 82 10 <0.10 <1.2 0.13 0.86 0.31 0.36 0.22 Seed 1.99

- 2.26 (2.23

- 2.53) 6

- 8 10 0.54 15 0.71 12 2.7 4.4 3.9 U.S. Trials 3 Glyphosate Forage 2.11

- 2.17 (2.36

- 2.43) 27

- 55 6 <0.05 <0.05 0.05 0.05 0.05 0.05 NA Seed 55

- 77 6 <0.05 <0.05 0.05 0.05 0.05 0.05 NA N
- acetyl
- glyphosate Forage 2.11

- 2.17 (2.36

- 2.43) 27

- 55 6 <0.05 2.8 0.07 2.7 0.38 0.73 1.0 Seed 55

- 77 6 0.06 1.9 0.14 1.5 0.26 0.47 0.51 AMPA Forage 2.11

- 2.17 (2.36

- 2.43) 27

- 55 6 <0.05 <0.05 0.05 0.05 0.05 0.05 NA Seed 55

- 77 6 <0.05 <0.05 0.05 0.05 0.05 0.05 NA N
- acetyl AMPA Forage 2.11

- 2.17 (2.36

- 2.43) 27

- 55 6 <0.05 0.14 0.05 0.13 0.05 0.06 0.03 Seed 55

- 77 6 <0.05 0.69 0.05 0.55 0.06 0.14 0.20 Combined glyphosate and N
- acetyl
- glyphosate Forage 2.11

- 2.17 (2.36

- 2.43) 27

- 55 6 <0.10 <2.9 0.12 2.8 0.43 0.78 1.0 Seed 55

- 77 6 <0.11 2.0 0.19 1.6 0.30 0.53 0.53 1 Except for sample min/max, values reflect per

- trial averages; n = no. of field trials. For calculation of LAFT (lowest

- average
field

- trial), HAFT (highest

- average
- field

- trial), median, mean, and standard deviation, the L OQ (0.0 5 ppm ) was used for any re sults reported as < LOQ. 2 Includes the side

- by

- side trial reflecting the Canadian use pattern conducted in the U.S. (Trial 21). 3 T rial 19 is not included as the study indicated that this trial may have received overspray due to drift from a neighboring field

.Glyphosate Summary of Analytical Chemistry and Residue Data DP#: 394964

page 12 of 15 

### 860.1520 Processed Food and Feed ( 483 98602 .der 2 ) 

### The petitioner submitted a n adequate processing study conducted with canola ( Event DP

Ø 73496

- 4). Thre e trials were established with each trial receiving application of a 4.17 lb ae/gal potassium glyphosate SL/L formulation as follows : (1) a preemergence soil application at 0.60

- 0.64 lb ae/acre; (2) a foliar broadcast application made at the 6

- leaf stage at 0.60

- 0.64 lb ae/acre ; and (3) a foliar broadcast application made 6

- 7 days before harvest a t 4.02

- 4.11 lb ae/acre. The total seasonal rate was 5.24

- 5.39 lb ae/acre (3.2x). Canola seed was harvested at a 6

- 7 days after the final application and were allowed to dry in the field for 4

- 10 days prior to collection. The seed from each trial was pro cessed meal and oil using cold press and solvent ext r action procedures. The seed and processed samples were analyzed for residues of glyphosate, N

- acetyl

- glyphosate, AMPA, and N

- acetyl AMPA using the DuPont TM HPLC/MS/MS method 15444 (all residues were quantitated in glyphosate equivalents). The method was adequately validated and is appropriate for data collection (storage interval has also been validated). Based on the LLMV, the LOQ is 0.05 ppm for analyte /matrices. Table 8 is a summary of the canola oil and meal processing factors. Residues of glyphosate, N

acetyl

- glyphosate, AMPA, and N

- acetyl AMPA do not concentrate in refined oil . Residues of N

acetyl

- glyphosate and N

- acetyl

- AMPA did concentrate in canola meal with processing factors of 1.1

- 1.5x and 1.9

- 2.1x, respectively. Residues of glyphosate, AMPA, and combined residues of glyphosate and N

- acetyl

- glyphosate did not concentrate in canola meal. Based on these result s , a separate tolerance in/on canola meal and oil for the combined residues of glyphosate and N

acetyl

- glyphosate are unnecessary.

Table 8 : Summary of Average Processing Factors
.

Analyte canola meal canola oil cold press solvent extraction cold press solvent extraction glyphosate 0.8x 0.6x <0.0 04 x N

- acetyl

- glyphosate 1.5x 1.1x < 0.0 5 x AMPA 0.4x <0.4x <0.4x N

- acetyl

- AMPA 2.1x 1.9x <0.1x combined glyphosate and N

- acetyl

- glyphosate 1.1x 0.9x <0.005xGlyphosate Summary of Analytical Chemistry and Residue Data DP#: 394964

page 13 of 15 

### 860.1850 & 860.1900 Confined and Field Accumulation in Rotational Crops Based on previously

- reviewed confined rotational crop studies (3.71 lb ae/acre (2.2x) ; MRIDs 41543201 and 41543202, A. Abramovitch, 14

- Oct

- 1992) which resulted in glyphosate residues of >0.01 ppm in barley grain only (0.018 ppm; 125

- day PBI) and the LOQ for the tolerance enforcement method of 0.05 ppm, HED previously concluded that a 30

- day PBI was appropriate for all non

- labeled crops (D200041, G. Kramer, 12

- May

- 1994; field rotational crop study has not been submitted). B as ed on the LOQ for the tol erance
- enforcement method and since the confined rotational crop study employed an exaggerated rate and employed application to bare soil , a 30

- day PBI for all non
- labeled crops is acceptable following application to Optimum® GLY canola . A revised Section B is requested. 860.1550 Proposed Tolerances Based on the available data, HED agrees with the petitioner’s proposal to mo ve the currently

established 20

- ppm canola seed tolerance from 180.364(a)(1) where the tolerance expression is for residues of only glyphosate to 180.364(a)(2) where the tolerance expression is for combined residues of glyphosate and N

- acetyl

- glyphosate (expressed in glyphosate equivalen ts). Canadian and C ode x maximum residue limits (MRLs) are currently established in/on canola seed at 10 ppm (combined residues of glyphosate and AMPA) and 20 ppm (residues of glyphosate only) , respectively (see attachment 2)

. HED notes that DuPont has al so petitioned the Canadian Pesticide management Regulatory Agency (PMRA) concerning application of glyphosate to Optimum® GLY; PMRA indicated that they are willing to increase the canola seed glyphosate MRL to 20 ppm. Therefore, the U.S., Canadian, and Co dex tolerance levels will be harmonized but the tolerance expressions will be different.

Attachment 1

- Chemical Name and Structure Table Attachment 2

- IRL Sheet RDI: RAB1 Chemists ( 16

- Nov

- 20 1 1 ) T. Bloem:S10945:Potomac.Y ard 1:703

- 605

- 0217:7509P:RAB1Glyphosate Summary of Analytical Chemistry and Residue Data DP#: 394964

page 14 of 15 

### A ttachment 1
- Chemical Structures

C ompound S tructure Glyphosate
N

- (phosphonomethyl)glycine

N

- a cetyl

- glyphosate
N

- acetyl

- N

- (phosphonomethyl)glycine

AMPA (aminomethyl)phosphonic acid

N

- a cetyl

- AMPA [(acetylamino)methyl]phosphonic acid P O

O H O H N O H O O

C H 3Glyphosate Summary of Analytical Chemistry and Residue Data DP#: 394964

page 15 of 15 

### Attachment 2: IRL 

## International Residue Limits : Glyphosate ( 417300; 11/02/2011)
Summary of US and International Tolerances and Maximum Residue Limits Residue Definition US Canada Mexico 2 Codex 3 40 CFR 180.364(a)(2): glyphosate ( N

- (phosphonomethyl) glycine) and its metabolite N

- acetyl

glyphosate ( N

- acetyl

- N

- (phosphonomethyl)glycine ) calculated as the stoichiometric equivalent of glyphosate Plants: N

- (phosphonomethyl)glycine, including the metabolite aminomethylphosphonic acid glyphosate

Tolerance/Maximum Residue Limit (ppm)

Commodity 1 US Canada Mexico 2 Codex 3 canola seed 20 10 20 Completed: M. Negussie; 11/03/11 1 Includes only commodities of interest for this action. Tolerance values should be 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 stored wheat. (fat) = to be measure d on the fat portion of the sample. MRLs indicated as proposed have not been finalized by the CCPR and the CAC.