### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON , D.C. 20460

OFFICE OF C HEMICAL SAFETY AND P O LL UTION PREVENTION



### MEMORANDUM

Date: 8 / 5 / 20 15



### SUBJECT: Diflubenzuron. Petition for the Establi s hment of P e rmanent Tolerances and R eg i s trati o n for New u ses o n A lfal fa and Carrot ; and C rop group Expansion fo r P eac h Subgr o up 12-l 2B; Plum S ub group I 2- I 2C; Nut
, T ree , Group 14 ; and P e pper / Eggp l a nt S ub gro up 8-1 OB. 

### S umma ry of A n a l yt ical C h e mi stry a nd Re s idu e Data.

P C Co de: 108 20 I D ec i s ion No.: 4941 1 6 P e tition No.: 4E8306 DP B arcode: D4 23328 R eg i s trati o n No .: 400-46 1 Re g ul ato r y Action: Sec tion 

### 3 R egistra ti on Reregi s tr at i o n Case No.: 

### 144 Risk Assessment Type: NA TXR No.: NA CAS No.: 35367 -38-5 MR ID Nos .: 493995-0 

### I
, 493995-02, 493995-03
, 49 399 5-04,493995-05 40 CF R : 

### § 180.377



### F ROM: Su mitra B ose Biswas, Chemist

# ~~c(; ·

# ~~ 1 " 

### Ri s k Assessment Branch 

### V T H ea lth Effect s Division (7509 P)



### TH ROUGH: Geo r ge Kramer
, PhD
, Che mi s t ,

# De**gn ate** **i** e r

# ~-- Tom Bloem
, C h e mist
, D es i g nated R ev i ew Sc i e n ce Advi so r y Council fo r C hemi s tr y (Che m S ) H E D (7509 P )

A nd

D o nna S. Da v i s, Act in g Branch Chief Ri s k Assessment Branch V I H ea lth Eff ec t Di vis ion (7509 P )



### TO: A n drew E rtm a n / Barbara Madden Ri s k Int egration, Mi n or Use & 

### Emergency R esponse Branch R egis trati o n Di v i sio n ( RD ) (75 05P )

Page I of 43Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 2 of 43 

### Table of Contents 1.0 Executive Summary ............................................................................................................. 5
2.0 Regulatory Recommendations ............................................................................................. 6
2.1 Data Deficiencies/Data Needs .......................................................................................... 7
2.2 Tolerance Considerations ................................................................................................. 7
2.2.1 Enforcement Analytical Method ............................................................................... 7
2.2.2 Recommended Tolerances ........................................................................................ 8
2.2.3 Revisions to Petitione d-For Tolerances .................................................................... 9
2.2.4 International Harmonization ..................................................................................... 9
2.3 Label Recommendations .................................................................................................. 9
3.0 Introduction .................................................................................................................. ...... 10
3.1 Chemical Identity ........................................................................................................... 10
3.2 Physical/Chemical Characteristics ................................................................................. 10
3.3 Pesticide Use Pattern/Direct ions for Use (860.1200) ..................................................... 11
4.0 Metabolite/Degradate Residue Profile ............................................................................... 12
4.1 Summary of Plant Metabolism and Residues of Concern (860.1300) ....................... 12
4.2 Summary of Livestock Metabolism a nd Residues of Concern (860.1300) ................... 12
4.3 Summary of Confined Rotational Crops and Residues of Concern (860.l850) ............. 12
5.0 Residue Profile ............................................................................................................... .... 13
5.1 Residue Analytical Methods (860.1340) ........................................................................ 13
5.1.1 Data Collection Methods ........................................................................................ 13
5.1.2 Multi-Residue Methods (860.1360) ........................................................................ 16
5.1.3 Tolerance Enforcement Methods ............................................................................ 16
5.1.4 Submittal of Analytical Reference Standards (860.1650) ...................................... 16
5.2 Storage Stability (860.1380) .......................................................................................... 16
5.3 Residue Data .................................................................................................................. 18
5.3.1 Crop Field Trials (860.1500) .................................................................................. 18
5.3.2 Field Rotational Crops (860.1900) ......................................................................... 25
5.3.3 Processed Food and Feed (860.1520) ..................................................................... 26
5.3.4 Meat, Milk, Poultry, and Eggs (860.1480) ............................................................. 26
5.3.5 Food Handling (860.1460) ...................................................................................... 28
5.3.6 Water, Fish, and Irrigated Crops (860.1400) .......................................................... 28
6.0 Tolerance Derivation ......................................................................................................... 29 Attachment 1. Trial Number and Geographic Location Tables ................................................... 29 Attachment 2. Individual Sample and Average Field Trial Results ............................................ 30Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

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### Attachment 3. International Re sidue Limit Status Sheet ............................................................. 34
Attachment 4. OECD MRL Calc ulator Inputs and Results ......................................................... 36Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 4 of 43 Summary of Submitted Residue Chemistry Studies OPPTS 860 Series Guideline MRID Number Title

860.1500 493995-01 William P. Barney (2015); Diflubenzuron: Magnitude of the Residue on Alfalfa. 860.1340 493995-02 William P. Barney, Kathryn Homa (2015); Diflubenzuron: Magnitude of the Residue on Alfalfa. 860.1900 493995-03 K. S. Samoil (2015); Diflubenzu ron: Magnitude of the Residue on Carrot. 860.1850 860.1900 493995-04 William P. Barney (2013); Diflubenzuron: Magnitude of the Residue on Peach and Plum.

493995-05 R. W. Russel (2008), Dimilion 2L in Peaches and Plums: Magnitude of the Residue Study.Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

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### 1.0 Executive Summary
Diflubenzuron, ( N -[((4-chlorophenyl)amino)carbonyl]-2,6-di fluorobenzamide), a member of the urea-derivative chemical family, is classified as an insect growth regulator and is used as both an acaricide and insecticide. It is currently regist ered in the U.S. for use as a chitin inhibitor (prevents development from the immature to the j uvenile and adult stages). The main agriculture pests targeted for control with diflubenzur on are twig borer, stink bug, grasshopper, beet armyworm, soybean looper, rust mite, artichoke plume moth, and peanuts root knot nematode. Tolerances for residues of diflubenzuron, cu rrently established under 40 CFR §180.377, range from 0.02-55 ppm.
The Interregional Research Proj ect No. 4 (IR-4) is requesting a Section 3 Registration for Dimilin® 2L, an aqueous flowable formulati on of diflubenzuron, and the establishment of permanent tolerances as described below:

 A new use of diflubenzuron on carrot on the Dimilin® 2L labels and a tolerance for carrot, roots at 0.2 ppm.

 A new regionally restricted use of difl ubenzuron on alfalfa an d establishment of tolerances for residues on alfalfa forage, hay, and seed at 6 ppm, 20 ppm, and 0.9 ppm, respectively. The new use is to be included on the label for Dimilin® 2L. The propose uses are limited to states west of the Mississippi river.

 Expansion of the proposed use of diflubenz uron on peach to include all commodities in the updated peach crop subgroup (CSG) 12- 12B on the Dimilin® 2L label and a tolerance for residues on peach CSG 12-12B at 0.5 to harmonize with the Codex MRLs.

 Expansion of the proposed use of diflubenzur on on plum to include all the commodities in the updated plum CSG 12-12C on the Dimilin® 2L label and a tolerance for residues on plum CSG 12-12C at 0.5 to harmonize with the Codex MRLs. Additionally, a separate tolerance for residues on plum, prune, dried at 0.5 ppm was petitioned for.

 Expansion of the current use of diflubenzuron on pepper to include all commodities in the updated pepper/eggplant crop CSG 8-10B on th e Dimilin® 2L label and a tolerance for residues on pepper/eggplant CSG 8-10B at 1.0 ppm.

 Expansion of the current use of diflubenzuron on cotton to include all the commodities of cottonseed in the updated CSG 20C on the Dimilin ® 2L label and a tolerance for residues on cottonseed CSG 20C at 0.2 ppm.

 Conversion of the nut, tree, group 14 tolerance to the upda ted nut, tree, crop group (CG) 14-12 on the Dimilin® 2L label and tolerances for residues on this CG at 0.2 ppm to harmonize with the Co dex MRL tolerance.

 Increase the egg and poultry fat toleran ces from 0.05 ppm to 0.15 ppm to support the proposed diflubenzuron use on alfalfa.

 Increase the poultry meat byproducts from 0.05 to 0.06 ppm to support the proposed diflubenzuron use on alfalfa.Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 6 of 43 

### The submitted labels are adequate.

The nature of the residue in plants (primary and rotational) and livestock is adequately understood to support the requested new uses. The re sidues of concern in plants (primary and rotational) and livestock are diflubenzuron and its metabolites 4-chlorophenylurea (CPU) and PCA (4-chloroaniline).

The previously submitted confined and field rotational crop studies are adequate to address rotational crop considerations fo r this action and suppor t the proposed 30-day plantback interval (PBI) for food and feed crops.

Adequate enforcement and data collection methods are available to determine the residues of diflubenzuron and its metabolites (CPU a nd PCA) in plants and livestock. FDA multi-residue method (MRM) testing data i ndicate that neither diflubenzuron, PCA, nor CPU are adequately recovered
The number, geographic representation, and the em ployed use patterns of the alfalfa, carrot, peach, and plum field trial data are adequate a nd support the requested us e patterns. The residue data were generated using a validated data collection method, and are supported by adequate storage stability data. The maximum combined residues of diflubenz uron, CPU and PCA in/on alfalfa forage/hay/seed, carrot, peach, and plum were as follows, respectively: 3.60/13.3/0.48 ppm, 0.08 ppm, 0.48 ppm, and 0.23 ppm.

No new field trial data were submitted to support expansion of the current uses to CSG 8-10B, CSG 20C and to support the conversion of CG 14 to 14-12. Since the requested expansions/conversion of the cr op groups are for the identical formulation and use pattern, no new residue chemistry data, includi ng processing studies, are requi red to support these requests.

Maximum reasonable dietary burdens (MRDBs) fo r diflubenzuron were calculated based on the proposed/registered uses. A comparison of the updated dietary burdens with previously submitted and adequate ruminant and poultry feedi ng studies demonstrate that the current milk and ruminant tissue tolerance are adequate to co ver the proposed/registered uses. However, egg and poultry tissue tolerances as indicated in Table 2.2.2 should be established.

There are no issues with respec t to international ha rmonization associated with this petition.

The previously submitted processed food and feed study on prune (dried plums) is adequate. Based on the study diflubenzuron residues do not concentrate in/on prunes.

2.0 Regulatory Recommendations

Provided a revised section F (as noted in Sectio n 2.2.2) and analytical standards for metabolite CPU and PCA (as noted in Section 5.1.4) ar e submitted, there are no residue chemistry considerations that would preclude granting the requested use on peach and plum SCGs, on carrots and regionally restricted use on alfalfa forage, hay, and seed; as well as the necessary tolerances, as listed in Section 2.2.2, required to support those uses.

Additionally, HED has no objection to the propos ed expansions/conversion of the following CGDiflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 7 of 43 

### and CSG:

 Expansion of the proposed use of diflubenzur on on peach to include all members of the peach SG 12-12B.

 Expansion of the proposed use of diflubenzur on on plum to include all members of the plum CSG 12-12C.

 Expansion of the current use of diflubenzuron on pepper to include all commodities of pepper/eggplant CSG 8-10B.

 Expansion of the current use of diflubenzur on on the Cotton, undelinte d seed to include all the commodities of cottonseed CSG 20C.

 Conversion of the nut, tree, group 14 tolerance to nut, tree, group 14-12.
Lastly, IR-4 has proposed new/increased livest ock tolerances. HED has concluded that the proposed tolerances are adequate to c over secondary residue s in livestock.

2.1 Data Deficiencies/Data Needs

None

2.2 Tolerance Considerations

2.2.1 Enforcement Analytical Method Residue Chemistry Chapter of the Diflubenzuron RED (DP# 209032, S. Knizner, 3/15/1995) DP# D285141 (G. Kramer, 9/6/2002)


### Adequate enforcement analytical methods are av ailable for the enforcement of tolerances for residues of diflubenzuron and its metabolites in crop and livestock commodities. Three enforcement methods for diflubenzuron are published in PAM, Vol. II as Methods I, II, and III. Method I is a GC/ECD method that determines di flubenzuron in plants as derivatized PCA. Method II is a GC/ECD method that can separa tely determine residues of diflubenzuron, CPU and PCA in eggs, milk, and livestock tissues, each as derivatized PCA. Method III is an HPLC/UV method that determines di flubenzuron per se in eggs, m ilk, and livestock tissues. All three methods have undergone successful Agency validations. The Diflubenzuron RED stated that Methods I and II are the preferred enforcemen t methods because they are easier to perform, have less interference, a nd are more sensitive.

In conjunction with PP#8F4925 on rice, a new analytical methodology for plant commodities was successfully validated by an independent la boratory as well as by Agency chemists at ACB/BEAD, and was forwarded to FDA for publ ication in PAM Vol. II as Roman Numeral Methods. These methods can separately determ ine residues of diflubenzuron by GC/ECD, CPU by GC/ECD, and PCA by GC/MS using an isotop ically labeled internal standard and by summing the response of the two ions. The re ported LOQ for diflubenzuron in/on rice grain, straw, and bran is 0.01 ppm, and is 0.05 ppm in/on rice hull. In rice straw, the LOQ for CPU is 0.01 ppm and 0.005 ppm for PCA.Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 8 of 43 

### FDA multi-residue method (MRM) testing data i ndicate that neither diflubenzuron, PCA, nor CPU are adequately recovered

2.2.2 Recommended Tolerances
Tolerances are currently establishe d under 40 CFR §180.377 comply with the HED Interim Guidance on Tolerance Expressions (S. Knizner, 5/27/09); th erefore, no revisions are recommended to the residue definition. Tabl e 2.2.2, below summarizes the recommended tolerance levels and commodity definitions required to suppor t the proposed new and revised uses included in these petitions.

IR-4 is requested to submit a revise d section F for the following reasons,

1) to remove the request for tolerance on plum, prune, dried. Based on a previously conducted processing study (MRID# 25252208) diflubenzuron re sidues are not found to concentrate on prunes (dried plum). Therefore, a separate tolerance for prunes is not required.

2) to revise the tolerances for poultry egg, fat and meat byproducts. Base d on the current dietary burden calculation, the an ticipated residues in poultry fat, egg and meat byproducts are different than what was proposed.

Table 2.2.2. Tolerance Summary for Diflubenzuron. Commodity Proposed Tolerance (ppm) HED-Recommended Tolerance (ppm) Comments ( correct commodity definition ) 40 CFR §180.377(a)(1) Tolerance for residues. Cottonseed subgroup 20C 0.2 0.20 Significant figures. Established tolerance for cotton, undelinted seed can be removed from 40CFR and replaced by this subgroup tolerance. Egg 0.15 0.07 Current tole rance level is 0.05 ppm; Increase to support the diflubenzuron uses on alfalfa.

Poultry, fat 0.15 0.10 Current tolerance level is 0.05 ppm; Increase to support the diflubenzuron uses on alfalfa. Poultry, meat byproducts 0.06 0.08 Current tolerance level is 0.05 ppm; Increase to support the diflubenzuron uses on alfalfa. 40 CFR §180.377(a)(2) Tolerance for residues. Carrot, roots 0.2 0.20 Significant figures.

Peach subgroup 12-12B 0.5 0.50 Significant figures. Established tolerance (0.07 ppm) for fruit, stone, group 12, except cherry

can be removed from 40CFR and replaced by this subgroup tolerance. Plum subgroup 12-12C 0.5 0.50 Significant figures. Established tolerance (0.07 ppm) for fruit, stone, group 12, except cherry

can be removed from 40CFR and replaced by this subgroup toleranceDiflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 9 of 43 Table 2.2.2. Tolerance Summary for Diflubenzuron. Commodity Proposed Tolerance (ppm) HED-Recommended Tolerance (ppm) Comments ( correct commodity definition ) to harmonize with codex. Plum, prune, dried 0.5 -- A separate tolerance is not required. Diflubenzuron residues are not found to concentrate on prunes (dried plum). Nut, tree, group 14-12 0.2 0.20 Significant figures. Established tolerance for pistachio

and nut, tree, group 14 can be removed from 40CFR and replaced by this subgroup tolerance to harmonize with codex. Pepper/Eggplant subgroup 8-10B 1.0 1.0 Established tolerance for pepper can be removed from 40CFR and replaced by this subgroup tolerance. 40 CFR 7180.377(c) Tolerances with regional registrations. Alfalfa, forage 6 6.0 Significant figures.

Alfalfa, hay 20 20 Alfalfa, seed 0.9 0.90 Significant figures.



### 2.2.3 Revisions to Petitioned-For Tolerances

R-4 is requested to submit a revised section F to remove the request for tolerance on Plum, prune, dried and to revise the tolerance for poultry fat, meat byproduct as outlined in section 2.2.2. Based on a previously conducted processing study (MRID# 25252208) diflubenzuron residues are not found to concentrate on prunes (dried plum) a tolera nce for prunes is not required. In addition, HED is recommending a numbe r of changes in the nu merical expression of the tolerance values in order to conform to current HED policy on significant figures.

2.2.4 International Harmonization

The Codex Alimentarius has established maximum residue limits (MRLs), expressed in terms of diflubenzuron per se , for many commodities including: peach CSG 12-12B (0.5 ppm), plum CSG 12-12C (including prunes) (0.5 ppm), nut tree (0.2 ppm), for chili pepper (3 ppm), dried chili pepper (20 ppm), sweet pepper (0.7 ppm), a nd for eggs (0.05 ppm). There are no Canadian or Mexican MRLs currently esta blished. The International Residue Limit (IRL) status sheet is included as Attachment 3 to this memorandum.
The Agency is currently not harmonized with Co dex with respect to the residue definition in plant and livestock commodities. Since the Code x MRL is based on the same use pattern and data that EPA would rely on, HED recommends an increase in the peach CSG 12-12B tolerance to 0.50 ppm, plum CSG 12-12C tolerance to 0.5 0 ppm, and nut, tree, group tolerance to 0.20 ppm to harmonize with the Codex MRL levels.

2.3 Label Recommendations

NoneDiflubenzuron Summary of Analytical Chemistry and Residue Data D423328

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### 3.0 Introduction

Diflubenzuron, ( N -[((4-chlorophenyl)amino)carbonyl]-2,6-di fluorobenzimide), a member of the urea-derivative chemical family, is classified as an insect growth regulator and is used as both an acaricide and insecticide. It is currently registered in the U.S. for use as a chitin inhibitor, which promotes an inability of immature insects to synthesize chitin to form a hard exoskeleton prevents development from the immature to the juvenile and adult stages. The main agriculture pests targeted for control with diflubenzur on are twig borer, stink bug, grasshopper, beet armyworm, soybean looper, rust mite, artichoke plume moth, and peanuts root knot nematode. Tolerances for diflubenzuron, currently es tablished under 40 CFR §180.377, range from 0.02-55 ppm.
3.1 Chemical Identity

The chemical structure and nomenclature of difl ubenzuron and its metabolites is shown in Table 3.1.

Table.3.1. Diflubenzuron Nomenclature. Compound

Common Name Diflubenzuron Trade and other Names Dimilin, Vigilante, Micromite, Adept IUPAC Name 1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea CAS Name N -[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide CAS Registry Number 35367-38-5 End-Use Products (EP) 2 lb/gal FlC formulation; DIMILIN ® 2L (EPA Reg. No. 400-461); 25% WP formulation; DIMILIN ® 25W (EPA Reg. No. 400-465); 80% G formulation; Micromite ® 80WGS (EPA Reg. No. 400- 487); Regulated Metabolite

Common name 4-chlorophenylurea (CPU) Regulated Metabolite

Common Name 4-chloroaniline (PCA)



### 3.2 Physical/Chemical Characteristics

Diflubenzuron is a white crystallin e solid, the technical material is off-white to yellow crystals. Melting points of the technical material is 210-230°C, and the pure form of 230-232°C (both with decomposition). The compound is sparingly sol uble in water. In polar solvent the solubility F

F O N H

O N H

Cl

O N H

Cl NH

2

Cl NH

2Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

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### is moderate to good depending on the degree of polarity. It is a non-volatile compound. The physicochemical properties of diflubenzu ron are presented in Table 3.2.

Table 3.2. Physicochemical Properties of Diflubenzuron. Parameter Value Reference Melting range 230-232 °C http://www.arsusda.gov/acsl/services/pp db/textfiles/DIFLUBENZURON pH Not available Density Not available Water solubility (25 °C) 0.08 ppm Solvent solubility (25 °C) (ppm) 6.5 x 10 3 Acetone 2 x 10 3 Acetonitrile 2.4 x 10 4 Dioxane 1.04 x 10 5 Dimethylformamide 1.2 x 10 5 Dimethylsulfoxide 1 x 10 3 Methanol 6 x 10 2 Dichloromethane Vapor pressure (25 °C) 1.2 x 10 - 4 mPa Dissociation constant, pK a Not available Octanol/water partition coefficient, Log(K OW ) 3.89

UV/visible absorption spectrum Not available



### 3.3 Pesticide Use Pattern/Directions for Use (860.1200)

Chemtura Corporation has submitted a label for Dimilin® 2L (EPA Reg No. 400-461) which includes proposed use directions for carrot, members of the pepper/eggplant CSG 8-10B, peach CSG 12-12B, plum CSG 12-12C, cotton seed CS G 20C, nut, tree group 14-12; and a regionally restricted use directions for al falfa (forage, hay, and seed). The proposed new use patterns for are summarized in the table below.

Table 3.3. Summary of Proposed Us e Directions for Use of Diflubenzuron. Applic. Timing, Type, and Equip. Formulation [EPA Reg. No.] Applic. Rate (lb ai/A) Max. No. Applic. per

Season Max. Seasonal Applic. Rate

(lb ai/A) PHI (days) Use Directions and Limitations Alfalfa (forage, hay, and seed)

Foliar by ground or air equipment. Dimilin® 2L [400-

461] 0.0325 3 0.0975 1 For use in the states West of the Mississippi River. Minimum interval between the applications is 14 day. Carrot Foliar by ground equipment. Dimilin® 2L [400-

461] 0.125 2 0.25 7 For use in CA. Minimum interval between the applications is 7 day. Peach Subgroup 12-12B Airblast by ground equipment. Dimilin® 2L [400-

461] 0.25 2 0.50 14 Minimum interval between the applications is 7 day. Plum Subgroup 12-12C Airblast by ground equipment. Dimilin® 2L [400-

461] 0.25 2 0.50 14 Minimum interval between the applications is 7 day.Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 12 of 43 

### Additionally, Chemtura requested followi ng to include in the proposed label:

 Crop group conversion of currently registered CG 14 commodities to commodities in CG 14- 12 on the Dimilin® 2L label. The proposed use pattern for CG 14-12 commodities is identical to that currently registered on these two labels for CG 14 commodities.

Conclusions: The proposed label directio ns are adequate to allow ev aluation of the residue data relative to those proposed new uses.

4.0 Metabolite/Degradate Residue Profile Summary of Plant Metabolism Studies (DP# 272978, G. Kramer, 4/3/2001) HED Metabolism Assessment Review Committee (MARC) Meetings of 2/20/2001 and 5/8/2001. Residues of Concern for Cancer Risk Assessment (DP# 272976, G. Kramer and G. Reddy, 5/31/2001)


### 4.1 Summary of Plant Metabolism and Residues of Concern (860.1300)
The qualitative nature of the residue in plants is adequately understood based on data from citrus, mushroom, rice, and soybean metabolism studies . The metabolism of diflubenzuron in crops tested is similar, and the radi oactive components are also sim ilar to those found in soil. The residues of concern for diflubenzuron for risk assessment and tolerance enforcement in plants and fungi, determined by MARC is diflubenzuron and its metabolites CPU and PCA.

Conclusions. The nature of the residue in plants has been adequately addressed and no additional data are required.

4.2 Summary of Livestock Metabolis m and Residues of Concern (860.1300) HED Metabolism Assessment Review Committee (MARC) Meetings of 2/20/2001 and 5/8/2001. Residues of Concern for Cancer Risk Assessment (DP# 272976, G. Kramer and G. Reddy, 5/31/2001)


### The nature of the residue in livestock is adequately understood based on acceptable poultry and ruminant metabolism studies reflecting oral dos ing. The MARC has concluded that the residues of concern in livestock for the purpose of risk assessment and enforcement are diflubenzuron and its metabolites PCA and CPU.

Conclusions. The nature of the residue in livest ock has been adequately addressed and no additional data are required.

4.3 Summary of Confined Rotational Cr ops and Residues of Concern (860.l850) MRID 43274101 (DP# 205481, S. Knizner, 2/2/1995); G. Kramer DP#s 321623, 321625, and 321627, 9/14/2006


### Although, the available c onfined rotational crop study was in adequate to fully satisfy the 860.1850 guideline, the nature of the residue in rotational crops is adequately understood for purposes of this petition. The re sidues of concern in rotationa l crops are parent diflubenzuron, CPU, and PCA.

Conclusions: Although, available confined rotational crop study was not adequate, the nature of the residue in rotational crops has been adequately delineated. Additional confined rotational crop data are not required at this time.Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

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### 5.0 Residue Profile

5.1 Residue Analytical Methods (860.1340)

5.1.1 Data Collection Methods 493599501.der, 6/15/2015,S. Biswas (alfalfa) 493599502.der 6/15/2015, S. Biswas (alfalfa) 493599503.der 6/15/2015, S. Biswas (carrot) 493599504.der 6/15/2015, S. Biswas (peach and plum) 493599505.der 6/15/2015, S. Biswas (peach and plum)



### Alfalfa Registrant has submitted two sets of field tria l studies for alfalfa. The original study (MRID #493599501) was conducted to analy ze the parent diflubenzuron only. In this study Residues of diflubenzuron in/on alfalfa forage, hay and s eed were quantified by LC/MS/MS using a method derived from “Diflubenzuron: Magn itude of the Residue in Small Grains” by Janine Rose, Ph.D., IR-4 Study 08024, PTRL Study 1129W, July 28, 2004. Method modifications did not negatively affect the performance of the method.
Residues of diflubenzuron were extracted from alfalfa forage, hay, or seeds by repeatedly extracting with acetonitrile. The extract was repeatedly partitioned with hexane and the combined hexane partitions were discarde d. The remaining acetonitrile extract was rotoevaporated to dryness and reconstituted with ace tonitrile. The reconstituted acetonitrile extract was passed through a pre-conditioned C18-SPE car tridge for clean-up followed by additional clean-up using a Si-SPE cartridge. The solvent was evaporated and the residue was reconstituted in acetonitrile and water. Sample s were analyzed by LC/MS/MS.

Method validation and concurrent method recovery data were pr ovided. Samples were fortified with diflubenzuron at 0.05-5.0 ppm . Recoveries were within th e acceptable range of 70-120%. The fortification levels used in method validati on and concurrent method r ecovery were adequate to bracket expected residue levels. The LOQ, determined as the lowest level of method validation (LLMV), was 0.050 ppm for diflubenzuron in alfalfa forage and seeds, and 0.50 ppm in alfalfa hay. The calculated limit of detection (LOD) was 0.025 ppm.

A second study (493599502) was conducted according to the ChemSAC decision (5/30/2007) to analyze diflubenzuron, PCA, and CPU residues in alfalfa commodities and to estimate the PCA and CPU residues in the trials from the origin al study. In this study, re sidues of diflubenzuron, CPU, and PCA in/on alfalfa forage, hay and se ed were quantified by LC/MS/MS using methods derived from the reference methods: “Diflube nzuron: Magnitude of the Residue in Small Grains.” Janine E. Rose, Ph.D., IR-4 Study 08024, PTRL Study 1129W, July 28, 2004, and “Dimilin 25W, Dimilin 80WG and Dimilin 2L in Almonds, Magnitude of the Residue Study,” Author: Janine E. Rose, Uniroyal Study No. RP-98003, September 13, 1999.

For analysis of diflubenzuron and CPU, proce ssed sample matrix was homogenized, centrifuged, and extracted three times with acetonitrile. The acetonitr ile layers were collected and further diluted into the calibration standard range with purified regent water and/or 10:90 acetonitrile:purified reagent water (v:v). If part icles were present, the sample was centrifuged prior to analysis by LC/MS/MS. The calculate d LODs for diflubenzuron residues on alfalfa forage, hay, and seed samples were 0.01428, 0.01726, and 0.01624 ppm, respectively. The calculated LODs for CPU residues on alfalf a forage, hay and seed samples were 0.00156,Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 14 of 43 

### 0.00123 and 0.00152 ppm, respectively. The LLMV was 0.05 ppm for diflubenzuron and 0.005 ppm for CPU on alfalfa fo rage, hay and seed.

For PCA detection, processed sample matrix was fortified with the internal standard (13C6)4- chloroaniline).The fortified sample was vortexed th en allowed to settle with the cap off for five minutes. The sample was then extracted with 0.1 N hydrochloric acid solution (in purified regent water) and shaken at 60 o 

### C for 30 minutes, brought to room temp erature in a cold water bath, then centrifuged. The supernatant was then filtered an d the remaining pellet was extracted twice more. Both extractions were collected and ta ken to a final volume of 100 mL with 0.1N hydrochloric acid solution. The sample was furthe r diluted into the calib ration standard range with 10 mM ammonia formate solution (in purified r eagent water). If particles were present, the sample was centrifuged at 13,000 rpm for five minutes prior to analysis by LC/MS/MS.

The calculated LODs for PCA residues on alfa lfa forage, hay and seed samples were 0.00128, 0.00096 and 0.00098 ppm, respectively. The calculat ed LOQs for PCA residues on alfalfa forage, hay and seed were 0.00385, 0.00289 a nd 0.00294 ppm, respectively. The LLMV was 0.005 ppm for PCA on alfalfa forage, hay and seed.

The methods were validated both prior to and conc urrently with field trial samples of alfalfa forage, hay and seed matrices fortified with diflubenzuron, CPU a nd PCA at 0.005-50 ppm. Recoveries were within the accep table range of 70-120%. The fortif ication levels used in method validation and concurrent method recovery were adequate to bracket e xpected residue levels.

Carrot Residues of diflubenzuron, CPU, and PCA in/ on carrot were quantified by LC/MS/MS using methods derived from “Diflubenzuron: Magnitude of the Residue in Small Grains”, Janine E. Rose, Ph.D., Uniroyal Study No. 08024, PTRL St udy No. 1129W, or “Dimilin 25W, Dimilin 80WG, and Dimilin 2L in Almonds: Magnitude of Residue Study”, Janine E. Rose, Ph.D., Uniroyal Study No. RP-98003, September 13, 1999.

For analysis of diflubenzuron and CPU, the sa mple was homogenized, centrifuged, and then extracted three times using aceton itrile as the extraction solvent. The acetonitrile layers were collected and taken to a final volume of 80.0 mL with acetonitril e. For 4-chorophenyl urea, the sample was dried using a gentle stream of nitrogen, vortexed for 30 seconds after the addition of an aliquot of 10:90 aceton itrile:purified reagent water (v:v) and sonicated for five minutes. The sample was further diluted into the calibration st andard range with purifie d reagent water. If particles were present, the sample was centrif uged at 13,000 rpm for fi ve minutes prior to analysis by LC/MS/MS. The calculated LOD were calculated to be 0.01040 ppm (diflubenzuron), 0.00128 ppm (CPU) in/on carrot ra w agricultural commodity (RAC) samples.

For PCA the processed sample matrix was for tified with the intern al standard ([13C6]4- chloroaniline) for analysis. The sample was vortexe d then allowed to settle with the cap off for five minutes. Residues were extracted using 0.1N hydrochloric acid soluti on (in purified reagent water) and shaken at 60°C for 30 minutes, brought to room temperature in a cold water bath, then centrifuged. The supernatant was then filt ered and the remaining pe llet was extracted twice more. Both extractions were collected and taken to a final volume of 100 mL with 0.1N hydrochloric acid solution. Residue s were analyzed by LC/MS/MS. The LOD were calculated to be 0.00294 ppm (PCA) in/on carrot RAC samples.Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 15 of 43 

### Method validation and concurrent method recovery data were pr ovided. Samples were fortified with diflubenzuron, CPU and PCA at 0.005-0.50 ppm. Recoveries were within the acceptable range of 70-120%. The fortification levels us ed in method validation and concurrent method recovery were adequate to bracket expected re sidue levels. The LOQ, determined as the LLMV, for residues of diflubenzuron in/on carrot samples was 0.050 ppm and 0.005 ppm for CPU and PCA.

Peach and Plum Two peach and plum field trials studies were submitted in conjunction of the current petition. Studies were conducted by the re gistrant in 2005 and IR-4 in 2009 growing seasons. In both studies, peach and plum samples were analyzed for residues of diflubenzuron, CPU, and PCA by using validated modified analyt ical methods derived from, “Dimilin 25W, Dimilin 80WG, and Dimilin 2L in Almonds: Magnitude of Residue Study,” Janine E. Rose, Ph.D., Uniroyal Study No. RP-98003. This data collection methods wa s modified during both studies. The method was adequately validated in conjunction with the fiel d sample analyses. Method modifications did not negatively affect the pe rformance of the method.

In the 2005 field trials, the diflubenzuron method utilized reverse phase high pressure liquid chromatography (HPLC) as a separation tech nique. The CPU and PC A methods utilized capillary column gas chromatography (GC) as a separation technique. Samples analyzed for diflubenzuron were subjected to organic solvent extraction followed by solid phase extraction clean-up. Quantitation of diflubenzuron was by HPLC and the limit of quantitation (LOQ) was 0.05 ppm. The CPU method invo lved organic solvent extraction followed by solid phase extraction clean-up. Quantitation was by GC with an electron capture detector (ECD). PCA residues in peaches were extracted with dilute HCl after spiking the samples with an internal standard of 13C-PCA. The acidic extract was made alkaline and then was extracted with hexane. The PCA was cleaned-up on a Florisil column an d derivatized before quantitation by GC/Mass spectrometry (MS).

The LOQs for diflubenzuron, CPU, and PC A were 0.05, 0.01, and 0.005 ppm respectively.

In the 2009 study, for analysis of diflubenzuron and CPU, samples of peach and plum were homogenized, centrifuged, and extrac ted three times with acetonitril e. For CPU, subsamples of peach and plum were dried using a gentle str eam of nitrogen, vortexed for 30 seconds after the addition of an aliquot of 10:90 ace tonitrile:purified reagent water (v:v), and sonicated for five minutes. The diflubenzuron and CPU extracts were further diluted into the calibration standard range with purified reagent water. If particles were present, samples were centrifuged prior to analysis by LC/MS/MS. The LLMV for residues of diflubenzuron and CPU in/on peach and plum samples were 0.05 ppm and 0.005 ppm, respectively.

For PCA, the processed sample matrix was fo rtified with the internal standard ([13C6]4- chloroaniline) followed by vorte xing then were extracted with 0.1N hydrochloric acid and shaken at 60 °C for 30 minutes, brought to r oom temperature in a cold water bath, then centrifuged. The supernatant was then filtered and the remaining pellet was extracted twice more with 0.1N hydrochloric ac id, collecting each ex traction and taken to a final volume of 100mL with hydrochloric acid. The peach and pl um samples were further diluted into the calibration standard range with 10 mM ammonium formate in purified reagent water. The calculated LOD for PCA residues in/on peaches and plums were 0.00158 and 0.00058 ppm respectively. The LLMV for residues of PCA in/on peach and plum samples was 0.005 ppm.Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 16 of 43 

### The methods were validated prior to sample an alysis using control peach and plum samples fortified with diflubenzuron, CPU, or PCA at 0.005-0.5 ppm. Recoveries were within the acceptable range of 70-120%.

Conclusions: The residue analytical methods used to generate alfalfa, carrot, peach and plum field trial data have been adequa tely validated and are acceptable for data collection purposes.

5.1.2 Multi-Residue Methods (860.1360) PAM Vol. I, Appendix II DP# 194722, L. Edwards, 9/17/93: Transmission of MRM data for diflubenzuron to FDA. DP# 254273, J. Rowell, 12/15/1998: Transmissi on of MRM data for PCA and CPU to FDA 

### The registrant has submitted Multiresidue testing data for diflubenzuron that HED has forwarded to the FDA. Diflubenzuron, per se, was not found to chromatograph by GC, thus, the FDA multi-residue method (MRM) will not adequately recover diflubenz uron. In addition, the results of Multiresidue Method testing of PCA and CPU have been submitted and forwarded to FDA. Neither PCA nor CPU was adequately recovered.

Conclusions: FDA MRM testing data indicate that ne ither diflubenzuron, PCA, nor CPU are adequately recovered.

5.1.3 Tolerance Enforcement Methods

Refer to section 2.2.1.

5.1.4 Submittal of Analytical Reference Standards (860.1650)

An analytical standard for diflubenzuron is cu rrently available in the National Pesticide Standards Repository and does not expire until 1/31/2017. However, analytical standard for metabolites CPU and PCA are expi red and must be replaced.

The analytical reference standards must be se nt to the Analytical Chemistry Lab, which is located at Fort Meade. Send them to the atten tion of either Theresa Cole or Thuy Ngygen at the following address:

USEPA National Pesticide Standards Repository/Analytical Chemistry Branch/OPP 701 Mapes Road Fort George G. Meade, MD 20755 5350

The extended zip code must be used or the mail will be returned.

5.2 Storage Stability (860.1380) 493599502.der 6/15/2015, S. Biswas (alfalfa) 493599503.der 6/15/2015, S. Biswas (carrot) 493599504.der 6/15/2015, S. Biswas (peach and plum)Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 17 of 43 

### The storage intervals and conditions of samples fr om the crop field trials studies submitted to support the field trials in this petition are summarized below.

Alfalfa: A storage stability study was conduc ted concurrently with the alfa lfa field trial study. Samples of alfalfa were fortified with diflubenzuron, CPU and PCA at 0.5 ppm and 0.05 ppm, and stored frozen. Residues of diflubenzuron and its metabolites were stable in/on alfalfa forage, hay and seeds stored frozen for up to 322 days , 294 days and 259 days respectively.

The storage durations and conditions of samples from the crop field trials submitted to support these petitions are presented in Table 5.2.1.

TABLE 5.2.1. Summary of Storage Conditions

. Matrix (RAC) Storage Temperature (°C) Actual Storage Duration (days) Interval of Demonstrated Storage Stability (days) Diflubenzuron Alfalfa Forage

<-20 322 Residues of diflubenzuron were stable when stored frozen in alfalfa forage, hay and seed for up to 306 days (10 months). Alfalafa Hay 294

Alfalfa Seed 259

CPU Alfalfa Forage

<-20 322 Residues of CPU were stable when stored frozen in alfalfa forage, hay and seed

for up to 307 days (10 months). Alfalafa Hay 294

Alfalfa Seed 259 PCA Alfalfa Forage

<-20 322 Residues of PCA were stable when stored frozen in alfalfa forage, hay and seed

for up to 301 days (10 months). Alfalafa Hay 292

Alfalfa Seed 256



### Carrot: A storage stability study was conducted concurren tly in conjunction with the carrot field trial study. Samples of carrots were fortified with diflubenzuron, CPU and PCA at 0.5 ppm and 0.05 ppm respectively, and stored fro zen. Residues of diflubenzuron a nd its metabolite were stable in/on carrot samples stored frozen up to 1263 days (42 months).

The storage durations and conditions of samples from the crop field trials submitted to support these petitions are presented in Table 5.2.2.

TABLE 5.2.2. Summary of Storage Conditions.

Matrix (RAC) Storage Temperature (°C) Actual Storage Duration

(days) Interval of Demonstrated Storage Stability (days) Diflubenzuron

Carrot <-20 1248-1263 Residues of diflubenzuron were stable when stored frozen in carrot for up to 1263days (42 months). CPUDiflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 18 of 43 Carrot <-20 1248 Residues of CPU were stable when stored frozen in carrot for up to 1248 days (42 months). PCA

Carrot <-20 1263 Residues of PCA were stable when stored frozen in carrot for up to 1263days (42 months).



### Peach and Plums: A storage stability study was conducted concurren tly in conjunction with the peach and plum field trial study. Samples of peach and plum we re fortified with diflubenzuron, CPU and PCA at 0.5 ppm and 0.05 ppm respectively, and stored frozen. Residues of diflubenzuron and its metabolite were stable in/on peach and plum samp les stored frozen up to 911 days (30 months).

The storage durations and conditions of samples from the crop field trials submitted to support these petitions are presented in Table 5.2.3.

TABLE 5.2.3. Summary of Storage Conditions.

Matrix (RAC) Storage Temperature (°C) Actual Storage Duration (days) Interval of Demonstrated Storage Stability (days) Diflubenzuron Peach (without pits) <-20 867 Residues of diflubenzuron were stable when stored frozen in peach/plum (including dried) for up to 875 days (29 months). Plum (without pits) <-20 875

Dried Plum (without pits) <-20 800

CPU Peach (without pits) <-20 867 Residues of CPU were stable when stored frozen in peach/plum (including dried) for up to 875 days (29 months). Plum (without pits) <-20 875

Dried Plum (without pits) <-20 800

PCA Peach (without pits) <-20 903 Residues of PCA were stable when stored frozen in peach/plum (including dried) for up to 911 days (30 months). Plum (without pits) <-20 911

Dried Plum (without pits) <-20 841



### Conclusions . Adequate storage stability data are av ailable to support the storage conditions and intervals for samples from the submitted field trials.

5.3 Residue Data

5.3.1 Crop Field Trials (860.1500) 493599501.der, 6/15/15,S. Biswas (alfalfa) 493599502.der 6/15/15, S. Biswas (alfalfa) 493599503.der 6/15/15, S. Biswas (carrot) 493599504.der 6/15/15, S. Biswas (peach and plum) 493599505.der 6/15/15, S. Biswas (peach and plum)Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 19 of 43 

### Alfalfa: IR-4 conducted two sets of fiel d trials in NAFTA Growing Zone s for alfalfa (forage, hay, and seed) in 2004/05 and 2011 growing seasons. A total of twelve field trials were conducted in these two studies. The original st udy (MRID No. 493599501) was conducte d to analyze the parent diflubenzuron only. The second study (MRID No. 493599502) was conducted at 1X and 3X of the proposed application rate according to th e ChemSAC decision (Minutes of 5/30/2007 Chem SAC Meeting), and the ratio of the three compounds were used to estimate level of CPU and PCA in the trials from the original study.

Nine alfalfa field trials were conducted in the United States during 2004 and 2005 growing seasons (MRID No. 493599501). Trials were co nducted in NAFTA Growing Zones 8 (CO, 2 trials), 10 (CA, 3 trials), and 11 (ID, WA, 4 tria ls). A table comparing the submitted number of trials and geographical locations of the field trial data to the requirements outlined in the OCSPP Harmonized Test Guidelines is included in Att achment 1. At each field site, Treatment (TRT) 02 consisted of three applications and three forage and hay sample cuttings. One application was made 1 day before a sample cutting (the sa me interval was followed for the other two applications and sample cuttings). All TRT 02 applications targeted 0.0325 lb ai/A. TRT 03 (conducted at five field sites) cons isted of three or four (CO09) applications of 0.0325 lb ai/A at 14 (±1) day re-treatment interval s (RTIs), with the last applica tion 1 day before collection of seed samples. At field trial 08678.04-ID04, the second application was made 19 days after the first application. One pint per ac re of emulsified vegetable or paraffinic crop oil was included to aid in canopy penetration and to minimize water ev aporation in both treatm ents. At field trials ID04, WA09, CA02 and CO09, seed samples were not collected due to poor seed set. The preharvest interval (PHI) was 1 day for all trials (TRT 02 and 03).

Harvested alfalfa forage, hay, and seed samples were analyzed by a validated data collection method as mentioned in section 5.1 (storage intervals were also validated)The limit of detection (LOD) for this method was 0.025 μg/mL and the limit of quantitation (LOQ) was 0.05 ppm in alfalfa forage and seed, and 0.50 ppm in alfalfa hay. Following three applications of diflubenzuron, thr ee forage and hay sample cuttings, and a PHI of 1 day, the maximum residues of diflubenz uron for TRT 02 were 2.9 ppm and 9.1 ppm in alfalfa forage and alfalfa hay, resp ectively. Residues were found to increase from the first to the third cutting at trial si te CO09. Therefore, the forage and ha y samples from the last cutting were the only samples analyzed in other trials (except for the first forage cutting in the CO01 trial).

The submitted field trials for alfalfa comm odities reflect the propos ed crop use pattern. Following three applications of diflubenzuron at 14 (±1) day intervals a nd a PHI of 1 day, the maximum residue of diflubenzuron in alfalfa se ed for TRT 03 was 0.43 ppm. No quantifiable residues (>LOQ) of diflubenzuron were detected in untreated control alfalfa forage, seed, and hay samples from all field sites. A residue de cline study was not conducte d. Individual sample and average field trial residue va lues are shown Attachment 2.

TABLE 5.3.1.1. Summary of Residue Data from Crop Field Trials with Diflubenzuron.

Commodity Total Applic. Rate

(lb ai/A) PHI (days) Diflubenzuron (ppm) n Min. Max. HAFT 1 Median Mean Std. Dev. Alfalfa Forage 2 0.10 1 18 0.82 2.9 2.5 1.8 1.8 0.50

Alfalfa Hay 2 18 2.6 9.1 8.2 5.2 5.3 1.8 Alfalfa Seed 10 0.056 0.43 0.43 0.18 0.23 0.15

1 HAFT = Highest Average Field TrialDiflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 20 of 43 2 Alfalfa forage and hay 3 rd cutting


### IR-4 conducted three additional alfalfa (forage, hay, and seed) trials in 2011 growing season based on the May 30, 2007 ChemSAC recommendations. Trials were conducted at 1X and 3X of the proposed application rate to es timate the levels of CPU and PCA in the trials from original study. Trials were conducted in the United States encompassing NAFTA Growing Zones 10 (CA; 1 trial) and 11 (ID and WA; 2 trials) dur ing the 2011 growing season. A table comparing the submitted number of trials and geographical locations of the field trial data to the requirements outlined in the OCSPP Harmonized Test Guidelines is included in Attachment 1. At each trial location, diflubenzuron (Dimilin 2L) wa s applied 3-4 times to alfalfa fields as a broadcast foliar application to f our treated plots. At the first treated plot at all sites, the application rate was 0.0314-0.0351 lb ai/A/application [Treatment (TRT) 02] for a total rate range of 0.0978 to 0.1290 lb ai/A per season (1X the la bel rate). At the second treated plot at all sites, the application rate ra nged from 0.0934 to 0.0982 lb ai/A/ application (TRT 03) for a total rate range of 0.2896 to 0.3808 lb ai/A per season (3 X the label rate). Three applications were made to the other two treated plots 12-15 days apart. The application rates ranged from 0.0317 to 0.0339 lb ai/A per application for a total rate range of 0.0967 to 0.1010 lb ai/A per season for TRT04. The application rates ranged from 0.0940 to 0.1007 lb ai/A per ap plication for a total rate range of 0.2891 to 0.2979 lb ai/A per season for TRT05. An adjuvant was added to the spray mixture for all applications, except at th e ID17 field trial fo r TRT 02 and TRT 03.

At all the field trials, forage and hay samples we re harvested 1 day after each application to the TRT02 and TRT03 plots. Seed samples were harv ested 1 day after the last application to the TRT04 and TRT05 plots.

The harvested alfalfa forage, hay and seed samp les were analyzed for residues of diflubenzuron, 4-chlorophenylurea (CPU), and 4-chloroaniline (PCA) by a validated da ta collection method mentioned in section 5.1 (storage intervals were also validated). The lowest level of method validation (LLMV) for residues of diflubenzur on in/on alfalfa samples was 0.050 ppm and the LLMV for residues of CPU and PCA in /on alfalfa samples was 0.005 ppm.

Individual sample and average field trial residue values are s hown Attachment 2.

Residues of diflubenzuron from the TRT02 plot ranged from <0.05-5.73 ppm and 2.9-15.6 ppm in forage and hay samples, respectively. Resi dues of diflubenzuron from the TRT03 plot ranged from <0.05-11.6 ppm and 7.5-45 ppm in forage and hay samples, respectively. Residues of diflubenzuron in seed samples ranged from <0.05-60.3 ppm and 0.36-2.0 4 ppm in TRT04 and TRT05 plots, respectively.

Residues of CPU and PCA were < 0.005 ppm for all forage seed samples. Residues of CPU in hay ranged from <0.005-0.105 ppm (TRT02) and < 0.005-0.144 ppm (TRT03). Residues of PCA in hay were <0.005 ppm (TRT02) and <0.005-0.00664 ppm (TRT03).

TABLE 5.3.1.2. Summary of Residue Data fr om Crop Field Trials with Diflubenzuron.

Commodity Total Applic. Rate (lb ai/A) PHI (days) Combined Residues of Diflubenzuron, CPU and PCA (ppm) 1 n Min. Max. HAFT 2 Median Mean Std. Dev. Alfalfa Forage 0.1

1 6 0.0600 5.74 3.60 1.56 1.98 1.94 0.3-0.4 3.40 11.6 9.70 6.06 7.71 4.99 Alfalfa Hay 0.1 4.36 15. 7 13.3 4.92 6.86 3.38 0.3-0.4 10.1 45.2 41.1 17.1 23.1 14.4Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 21 of 43 Alfalfa Seed 0.1 0.06 60.3 47.4 3 0.26 15.9 25.7 0.3 0.09 2.05 1.58 0.41 0.700 0.760

1 Residue values were from the third cutting
2 HAFT = Highest Average Field Trial.
3 This mean residue value for alfalfa seed from one field site wa s determined to be an outlier and was not included in the tolera nce calculation.


### In regards to the estimation of CPU and PCA residues in the original alfalf a study, please refer to the following tables in this section for these calculations based on the percentage of metabolites compared to the parent in the second alfalfa study. These data were used to calculate total residues used in the OECD calculator.

Table 5.3.1.3. Alfalfa Forage - Third Cutting (mean residues).

Trial Diflubenzuron 1 4-chlorophenyl urea 1 4-chloroaniline 1 Total ppm 1
.11-CA147 3.585 0.005 0.005 3.595 .11-ID17 0.86 0.005 0.005 0.870 .11-WA*33 1.495 0.005 0.005 1.505

2 Mean % of parent: 0.35 0.35
Calculated values Calculated values Total ppm .04-CO09 1.96 0.007 0.007 1.974 .04-ID04 2.54 0.009 0.009 2.558 .04-WA09 1.572 0.006 0.006 1.583 .05-CO01 2.182 0.008 0.008 2.197 .04-CA100 1.892 0.007 0.007 1.905 .05-CA01 1.15 0.004 0.004 1.158 .05-CA02 2.316 0.008 0.008 2.332 .05-ID01 1.548 0.005 0.005 1.559 .05-WA01 0.892 0.003 0.003 0.898

Alfalfa Hay - Third Cutting (mean residues)

Trial Diflubenzuron 4-chlorophenyl urea 4-chloroaniline Total ppm .11-CA147 13.2 0.082 0.005 13.287 .11-ID17 4.655 0.005 0.005 4.665 .11-WA*33 4.74 0.005 0.005 4.75 Mean % of parent: 0.3 0.09

Calculated values Calculated values Total ppm .04-CO09 6.384 0.019 0.006 6.409
.04-ID04 7.448 0.022 0.007 7.477 .04-WA09 5.208 0.016 0.005 5.228 .05-CO01 8.160 0.024 0.007 8.192
.04-CA100 4.411 0.013 0.004 4.428 .05-CA01 3.457 0.010 0.003 3.470 .05-CA02 5.220 0.016 0.005 5.240 .05-ID01 4.444 0.013 0.004 4.461 .05-WA01 2.896 0.009 0.003 2.907

1 Residue values were from the third cuttingDiflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 22 of 43 2 % of parent= average of (p pm metabolite*100)/ppm parent

Table 5.3.1.4. Alfalfa Seed (mean residues). Trial Diflubenzuron 4-ch lorophenyl urea 4-ch loroaniline Total ppm .11-CA147 0.248 0.005 0.005 0.258 .11-ID17 0.05 0.005 0.005 0.06

. 2 11- WA*33 47. 4 0. 005 0. 005 *47. 41

1 Mean % of parent: 6 6

Calculated values Calculated values Total ppm .05-CA01 0.132 0.008 0.008 0.148 .04-CA100 0.346 0.021 0.021 0.388 .05-CO01 0.431 0.026 0.026 0.483 .05-ID01 0.160 0.010 0.010 0.180 .05-WA01 0.068 0.004 0.004 0.076

1 % of parent= average of ( ppm metabolite*100)/ppm parent
2 the residue value from trial *11WA*33 was exclude d because it is considered as an outlier



### Conclusions : The number and geographic representation of the submitted field alfalfa samples are adequate to support the requested geographically restricted use in the states west of the Mississippi river. The re sidue data support the re quested use pattern.

Carrot: The IR-4 has submitted field trial data for use of diflubenzuron on carrot. Nine field trials were conducted in the United States during the 2008 growing season. Trials were conducted in NAFTA Growing Zones 10 (CA, 4 trials), 2 (GA, 2 tr ials), 5 (OH, 1 trial), 6 (TX, 1 trial), and 11 (WA, 1 trial). A table comparing the submitted numb er of trials and geographical locations of the field trial data to the requirements outlined in the OCSPP Harmonized Test Guidelines is included in Attachment 1. Each trial site consisted of one untreated plot a nd one treated plot. At each trial location, two folia r applications of the test substa nce (Dimilin 2L) were made at 6-8 days re-treatment interval (RT I) to the treated plots at rates of 0.119-0.129 lb ai/A per application for a total rate of 0.243-0.255 lb ai/A per season (1X the label rate). No adjuvant or additive was added to spray mixtures for any of the appli cations. Carrot RAC samples were harvested 6-7 days after the last application. At the CA88 trial, additional dup licate samples were collected at 3, 10, and 14 days after th e last application.

The harvested carrot RAC samples were an alyzed for residues of diflubenzuron, 4- chlorophenylurea (CPU), and 4- chloroaniline (PCA) by a vali dated data collection method mentioned in section 5.1 (storage intervals were also validated). The lowest level of method validation (LLMV) for residues of diflubenz uron in/on carrot samples was 0.050 ppm and 0.005 ppm for CPU and PCA.

Following two foliar applications of Dimilin 2L at 6-8 days RTI, combined residues of diflubenzuron, CPU, and PCA we re <0.06-0.08 ppm. In the dec line trial, combined residues were 0.06 ppm at pre-harvest intervals (PHIs) of 3, 7, 10 and 14 days. Individual sample andDiflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 23 of 43 

### average field trial residue va lues are shown Attachment 2.

Table 5.3.1.5. Summary of Residue Data from Crop Field Trials with Diflubenzuron.

Commodity Total Applic. Rate (lb ai/A) PHI (days) Combined Residues (Diflubenzuron + CPU + PCA) [ppm]

n Min. Max. HAFT 1 Median Mean 2 Std. Dev.

Carrot 0.243-0.255 3 2 0.06 0.06 0.06 - - - 6-7 18 0.06 0.08 0.07 0.06 0.06 0.004 10 2 0.06 0.06 0.06 - - - 14 2 0.06 0.06 0.06 - - -

1 HAFT = Highest Average Field Trial



### Conclusions : The number and geographic representation a nd residue data are adequate to support the requested use pattern.

Peach and Plum:
A total of 12 peach and 8 plum field trials were conducted in NAFTA growing zones during 2005 and 2009 growing season. A table comparing the submitted number of trials and geographical locations of the field trial da ta to the requirements outlined in the OCSPP Harmonized Test Guidelines is included in Attachment 1.

In 2005, 5 field trials for peach and 3 field tr ials for plum were conducted in NAFTA Growing Zones 10 (CA, 3 trials), 1 (PA, 1 trial), 2 (GA, 1 trial), 6 (TX, 1 trial) , 5 (MI, 1 trial), and 12 (WA, 1 trial).

At each trial location, which consisted of one untre ated plot and one treated plot, two air-blast applications of the test substance (Dimilin 2L) we re made at 14 days re-treatment interval (RTI) at rates of 0.243-0.259 lb ai/A pe r application (1X the label rate) to the treated plots. An adjuvant was added to each spray mixture. Peach and plum raw agricultural commodity (RAC) samples were harvested 14 days after the last application.

The harvested peach and plum RAC samples we re analyzed for residues of diflubenzuron, 4- chlorophenylurea (CPU), and 4- chloroaniline (PCA) by a vali dated data collection method mentioned in section 5.1 (storage intervals we re also validated). The LLMV for residues of diflubenzuron, CPU and PCA in/on peach and plum samples were 0.05 ppm, 0.01 ppm, and 0.005 ppm, respectively.

Individual sample and aver age field trial residue valu es are shown Attachment 2.

Following two foliar applications of Dimilin 2L at rates of 0.243-0.259 lb ai/A per application and 14 days RTI, combined residues of di flubenzuron, CPU, and PC A were 0.080-0.44 ppm in peaches without pits and 0.080-0.23 ppm in plums w ithout pits harvested at 14 days pre-harvest interval (PHI).Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 24 of 43 TABLE 5.3.1.6. Summary of Residue Data from Crop Field Trials with Diflubenzuron.

Commodity Total Applic. Rate (lb ai/A) PHI (days) Combined (Diflubenzuron + CPU + CPA) (ppm) N Min. Max. HAFT 1 Median Mean Std. Dev. Peach 0.489-0.510 14 15 0.08 0.44 0.24 0.18 0.16 0.05 Plum 9 0.08 0.23 0.19 0.17 0.20 0.10

1 HAFT = Highest Average Field Trial

. 

### In 2009, 7 field trials for peach and 5 field tria ls for plum were conducted in NAFTA Growing Zones 10 (CA, 6 trials), 2 (NC and NJ, 3 trials), 4 (AR, 1 trial), 5 (MI, 1 trial), and 11 (WA, 1 trial).

At each trial location, which consisted of one untre ated plot and one treated plot, two air-blast applications of the test substance (Dimilin 2L ) were made post bloom 13-15 days re-treatment interval (RTI) at rate s of 0.235-0.259 lb ai/A per application (1X the label rate ) to the treated plots. An adjuvant was added to each spra y mixture. Peach and plum raw agricultural commodity (RAC) samples were harvested 10-16 da ys after the last appl ication. At the CA41 trial, duplicate samples were collected 0, 7 and 21 days after the last ap plication. At the CA43 trial, duplicate samples of treated and untreated plums harvested 13 days after the last application were collected after drying.

The harvested peach and plum RAC samples were analyzed for residues of diflubenzuron, CPU, PCA by a validated data collection method mentioned in section 5.1 (storage intervals were also validated). The LLMV for residues of diflube nzuron in/on peach and plum samples was 0.05 ppm and 0.005 ppm for CPU and PCA.

Following two foliar applications of Dimilin 2L at 14 days RTI, combined residues of diflubenzuron, CPU and PCA were 0.060-0.48 ppm in peaches wit hout pits harvested at 14-16 days pre-harvest interval (P HI) and 0.060-0.12 ppm in plums w ithout pits harvested at 10-14 days PHI. In the decline trial, combined re sidues declined from 0.24 ppm at 0-day PHI to 0.08 ppm at 21-days PHI.

TABLE 5.3.1.7. Summary of Residue Data from Crop Field Trials with Diflubenzuron.

Commodity Total Applic. Rate (lb ai/A) PHI (days) Combined Residues (diflubenzuron, CPU and PCA) (ppm) n Min. Max. HAFT 1 Median Mean Std. Dev.

Peach 0.50 0 2 0.17 0.30 0.24 0.24 0.24 0.090 7 2 0.13 0.16 0.14 0.14 0.14 0.020 14-16 14 0.090 0.48 0.44 0.14 0.19 0.12

21 2 0.060 0.090 0.080 0.080 0.080 0.020 Plum 13-14 10 0.060 0.12 0.12 0.060 0.080 0.020 Dried Plum 13 1 0.20 0.20 NA 2 NA NA NA

1 HAFT = Highest Average Field Trial.
2 NA = Not applicable



### Conclusions : The representative commodities for th e peach CSG 12-12B a nd plum CSG 12-12C are peach and plum respectively. The number and geographic representation of the submitted peach and plum samples are adequate to s upport the requested use of Dimilin® 2L on the commodities in CSGs 12-12B and 12-12C.Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 25 of 43 

### Pepper/Eggplant CSG 8-10B No new field trial data were submitted to support the requested expansion of the current use on pepper to the pepper/eggplant CSG 8-10B.

Conclusions. The representative commodity for the pepper/eggplant CSG 8-10B is pepper. Since a pepper use is already on the label (Dim ilin® 2L) and since the proposed application scenario for the CSG 8-10B is identical to the currently registered pe pper use pattern, no new data are required to support the requested use on the CSG 8- 10B. The newly requested use on CSG 8-10B commodities is considered adequate ly supported by the residue data previously submitted to establish the pepper use.

Cottonseed CSG 20C No new field trial data were submitted to support the requested expansion of the current use on cotton to the pepper/eggplant CSG 20C.

Conclusions: The representative commodity for the cottonseed CSG 20C is cotton. Since a cotton use is already on the label (Dimilin® 2L) a nd since the requested CSG 20C use pattern is identical to the currently registered cotton use pattern, no new data are required to support the requested use on the crop cottonseed CSG 20C . The newly requested use on crop cottonseed CSG 20C commodities is considered adequately supported by the residue data previously submitted to establish the cotton use.

Nut, tree, group 14-12 No new field trial data were submitted to suppo rt the requested CG conversion from CG 14 to 14-12 and to support the expansion of current us e on the nut, tree, group 14 to the nut, tree, group 14-12.

Conclusions: The representative commodities and data requirements for CG 14 are identical to those for CG 14-12. Since the CG 14 uses are al ready on the labels (Dimilin® 2L) and since the requested use pattern for CG14-12 is identical to the currently register ed use pattern for CG14, no new data are required to support the requested use on the po me fruit CG 14-12. The newly requested use on CG 14-12 commodities is consider ed adequately supporte d by the residue data previously submitted to establish the CG 14 use.

5.3.2 Field Rotational Crops (860.1900) MRID 44689703 (DP#s 244487, 251221, 251609, 253041, 253043; G. Kramer, 2/17/99) 

### An acceptable limited field rotational crop study ha s been previously submitted. HED’s review of the study concluded that quant ifiable residues of diflubenzuron, CPU, and PCA are unlikely to occur in rotated crops planted at least 30 days after be ing treated with diflubenzuron. Currently, a PBI of 30 day is established for the food and feed crops.

Conclusions: The field rotational data and the current PBI of 30 day is ade quate to support the proposed uses of diflubenzuron. The proposed labe l contains 30-day PBI for all food and feed crops.Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 26 of 43 

### 5.3.3 Processed Food and Feed (860.1520) MRID 25252208 (DP# 277691; G. Kramer, 2/27/2002), ( 493599504.der x/x/15, S. Biswas (peach and plum) 

### The previously submitted processed food and feed study on prune (dried plums) is adequate. Based on the study diflubenzuron residues do not concentrate in/on prunes.

Additionally, based on the submitted data -combined residues of diflubenzuron, CPU and PCA in dried plums were 0.20 ppm (Table 5.3.3).

TABLE 5.3.3. Summary of Residue Data from Crop Field Trials with Diflubenzuron (dried plum).

Commodity Total Applic. Rate (lb ai/A) PHI (days) Combined Residues (diflubenzuron, CPU and PCA) (ppm) n Min. Max. HAFT 1 Median Mean Std. Dev. Dried Plum 13 1 0.20 0.20 NA 2 NA NA NA


### 5.3.4 Meat, Milk, Poultry, and Eggs (860.1480)

There are ruminant and/or poultry feed items associated with the proposed uses of diflubenzuron on alfalfa (forage, hay, a nd seeds) and carrot.

5.3.4.1 Dietary Burden

Maximum Reasonable Dietary Burdens (MRDBs) Although there are many plausible ways of estimating the MRDBs for diflubenzuron to livestock, the calculation of dietary burdens, presented in Table 5.3.4.1, largely incorporates the feed items associated with the current pet ition. The MRDBs of diflubenzuron are 3.39 ppm for beef cattle, 19.34 ppm for dairy cattle, 1.05 ppm for poultry, and 1.0 ppm for hog.

TABLE 5.3.4.1. Calculation of MRDBs. Crop Commodity Type 1 Residue %Dry Matter 2 %Diet Dietary Contribution 3 ppm input ppm Beef Cattle Alfalfa Hay R 20 HR 89 15 3.37 Wheat Grain CC 0.06 Median 89 20 0.01 Rice Bran CC 0.02 Median 90 15 0.003 Untreated feed NA NA NA NA NA 50 0 Total NA NA NA NA NA 100 3.39 Dairy Cattle Peanut Hay R 55 HR 85 15 9.71 Grass Forage R 6 HR 25 30 7.20 Carrot Culls CC 0.2 HR 12 10 0.17 Wheat Grain CC 0.06 Median 89 20 0.01 Rice Bran CC 0.02 Median 90 15 0.003 Alfalfa Meal PC 20 HR 89 10 2.25 Total NA NA NA NA NA 100 19.34 Poultry Wheat Grain CC 0.06 Median 89 75 0.05Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 27 of 43 Alfalfa Meal PC 20 HR 89 5 1.00 Untreated feed NA NA NA NA NA 20 0 Total NA NA NA NA NA 100 1.05 Swine Rice Bran CC 0.02 Median 90 10 0.002 Alfalfa Meal PC 20 HR 89 5 1.00 Untreated feed NA NA NA NA NA 85 0 Total NA NA NA NA NA 100 1

1 R: Roughage; CC: Carbohydrate con centrate; PC: Protein concentrate.
2 OCSPP 860.1000 Table 1 Feedstuffs (June 2008).
3 Contribution = ([tolerance /% DM] X % di et) for beef and dairy cattle; contribution = ([tolerance] X % diet) for poultry and h og.



### 5.3.4.2 Estimated Secondary Residues in Livestock Residue Chemistry Chapter of the Difl ubenzuron Registration Standard (11/84) Residue Chemistry Chapter of the Diflubenzuron RED (DP# 209032, S. Knizner, 3/15/1995)


### No livestock feeding studies were submitted with this petition. Numerous diflubenzuron feeding studies have been reviewed previously by HED. Those that are the most relevant to the current petitions are discussed below.

Ruminant: In one cattle feeding study, lactating cows were dosed orally twice a da y with diflubenzuron at either 25 (1.3X) or 250 (13x) ppm in the diet for up to 28 consecutive days. Residues of diflubenzuron per se were nondete ctable (<0.05 ppm) in milk from both feeding levels sampled following 1 to 28 days of dosing. Residues of diflubenzuron per se we re also nondetectable (<0.05 ppm) in the fat, muscle, liver, and kidneys of cows sacrificed after 8, 18, and 28 days of dosing at 25 (1.3X) ppm. For cows sacrificed after dosing at 250 (13X ) ppm for 8, 18, and 28 days, residues of diflubenzuron per se were nond etectable (<0.05 ppm) in the muscle and kidney, 0.06-0.08 ppm in fat, and 0.09-0.1 ppm in liver.

In the third feeding study, four dairy calves were fed diflubenzur on at a rate of 2.8 mg ai/kg body weight for 4-5 months and two were sacrificed. Then three others were fed at 1 mg ai/kg body weight for another year and sacrificed. The 2.8 and 1.0 mg/kg doses were equivalent to approximately 180 (9X) and 65 (3X) ppm, respectively, in the di et. Following dosing at 180 ppm (5x), residues of diflubenzuron were 0.02 ppm in liver and kidn ey, 0.04-0.08 ppm in fat, and <0.02 ppm in muscle. Residues of diflubenzur on per se were nondetectable (<0.02 ppm) in tissues from livestock after dosing at 65 ppm (3X).

Poultry: Acceptable data are also available for residues of diflubenzuron in eggs, meat, meat byproducts, and fat of poultry. The Residue Chemistry Chap ter of the Diflubenzuron Registration Standard (11/84) and the Addendum to the Diflubenzuron Registration Standard (12/84) cited five feeding studies on poultry. In one study, laying hens were orally dosed via capsule for 1-28 consecutive days at 0.05 (0.05X), 0.5 (0.5x), and 5 (5X) ppm of [14C]diflubenzuron in the diet. Hens were sacrificed at 3- to 7-day in tervals throughout the study. Residues of diflubenzuron per se were 0.21 ppm in fat after dosing at 5 ppm (5X) for 7 days. After 24 days of dosing at 5 ppm (5X), residues of diflubenzuron per se were 0.05 ppm in muscle a nd kidney, 0.16 ppm in liver, and 0.14 ppm in eggs. This feeding study encompasse s the currently calculated dietary burden for livestock and is used to calculate the expected secondary re sidues in poultry fat, egg and liver.Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 28 of 43 

### In another study, Black Barred Rock-Rhode Is land Red (BBR/RIR) and White Leghorn (WL) hens were given feed containing diflubenzuron at 10 ppm (10X) for 15 weeks. Residues of diflubenzuron per se plateaued in eggs after  2 weeks and remained constant at ~0.3-0.6 ppm for the remainder of the dosing period. Hens were s acrificed after a 3-day withdrawal period. For BBR/RIR hens, average residues of diflubenzuron were 1.17 ppm in fat, 0.12 ppm in liver, and nondetectable (<0.01 ppm) in muscle at the end of the dosing period. For WL hens, average residues of diflubenzuron were 1.85 ppm in fa t, 0.45 ppm in liver, and nondetectable (<0.01 ppm) in muscle at the end of the dosing period.

Male Hubbard chickens in another study were dosed for 98 days with feed containing diflubenzuron at 2.5 and 250 ppm, five hens at each level. At the 2.5 ppm feeding level (2.4X), residues of diflubenzuron per se were 2.2-6.9 ppm in fat, 0.09-0.45 ppm in muscle and skin, and 0.06-0.72 ppm in liver. At the 250 ppm feeding le vel (238X), residues of diflubenzuron were 23-62 ppm in fat, 0.9-3.3 ppm in muscle and skin, and 0.8-3.8 ppm in liver.
Expected secondary residues in fat, liver and egg are calculated based on the current dietary burden calculations. Summary of the calculations is pres ented in the table 5.3.4.2

TABLE 5.3.4.2. Diflubenzuron Expected Secondary Residues in Meat and Milk

Animal Matrix Residue Definition Dietary Burden (ppm) Anticipated Residue

(ppm) Rounded MRL (ppm)

Poultry Fat diflubenzuron 1.05 0.099 0.10

Poultry Liver/poultry meat byproducts diflubenzuron 1.05 0.076 0.08

Poultry egg diflubenzuron 1.05 0.066 0.07



### Conclusions: There are ruminant and/or poultry feed it ems associated with the proposed uses of diflubenzuron on alfalfa (forage, hay, and seed ) and carrot. The calcula ted maximum theoretical dietary burdens (3.39 ppm for beef cattle, 19.34 pp m for dairy cattle, 1.0 5 ppm for poultry, and 1.0 ppm for hog), resulting from the proposed/reg istered uses, are supported by previouslysubmitted livestock feeding studies. Based on the current dietary burden calculations, anticipated residues in poultry fat, liver and eggs are higher than the currently established tolerances. Based on the calculation, HED, recommends to establis h tolerances of diflubenzuron in poultry fat, liver/poultry meat byproducts and egg at 0.10 ppm, 0.08 ppm and 0.07 respectively.

5.3.5 Food Handling (860.1460)

There are no proposed uses that are relevant to this guideline topic.

5.3.6 Water, Fish, and Irrigated Crops (860.1400)

There are no proposed uses that are relevant to this guideline topic.Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 29 of 43 

### 6.0 Tolerance Derivation

The Agency’s Organization for Economic Cooperation and Development (OECD) MRL calculator was used to determine appropriate to lerance levels for the combined residues of diflubenzuron and its metabolite for alfalfa (for age, hay and seed), carrot, peach CSG 12-12B, plum CSG 12-12B. The results from the spre adsheet calculator support the HED-recommended tolerances listed in Section 2.2.2.

Attachments

Attachment 1. Trial Number and Geographic Location Tables Attachment 2. Individual Sample and Average Field Trial Results Attachment 3. International Residue Limit Status sheet Attachment 4. OECD MRL Ca lculator Inputs and Results

Attachment 1. Trial Number and Geographic Location Tables

TABLE A.1.1. Trial Numbers and Geographical Locations.

NAFTA Growing Zones Alfalfa

Submitted Requested

1 1 3 1 4 5 6 7 1 8 2 9 1 10 4 1 11 6 1 Total 1 12 12

TABLE A.1.3. Trial Numbers and Geographical Locations.
NAFTA Growing Zones Carrot

Submitted Requested Canada US 2 2 1 3 1 5 1 1 6 1 1 10 4 4 11 1 1 Total 9 8

1 Region 2 trials in this study were conducted in s outhern Georgia, near the border with Region 3.

TABLE A.1.5. Trial Numbers and Geographical Locations

. NAFTA Growing Zones Peach Plum

Submitted Requested 1 Submitted Requested Canada US Canada USDiflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 30 of 43 1 2 1 1A 1 2 4 4 3 4 1 1 5 1 1 1 1 5A 5B 6 1 1 7 7A 8 9 10 2 4 5 5 11 1 1 12 1 1 Total 12 12 8 8

.



### Attachment 2. Individual Sample and Average Field Trial Results

TABLE A.2.1. Alfalfa: Residue Data from Crop Field Trials with Diflubenzuron.

Trial ID (City, State/Year) Zone Crop/Variety Commodity or Matrix Total Rate (lb ai/A) PHI (days) Diflubenzuron (ppm) 1

1 st cutting 2 nd cutting 3 rd cutting 04-CO09 (Fort Collins, CO /2004) 2 8 Alfalfa/ Focus Forage 0.0972 1 1.24, 1.97 1.580, 1.924 2.25, 1.67 04-ID04 (Kimberly, ID /2004) 11 Alfalfa/ Rampage Forage 0.1040 1 2.19, 2.89 04-WA09 (Prosser, WA /2004) 11 Alfalfa/ Perfect A1 Forage 0.0956 1 1.67, 1.48 05-CO01 (Fort Collins, CO /2005) 8 Alfalfa/ Focus Forage 0.1000 1 1.85, 1.43 2.31, 2.05 04-CA100 (Holtville, CA/ 2005) 10 Alfalfa/ Cibola Forage 0.0962 1 1.86, 1.93 05-CA01 (Holtville, CA/ 2005) 10 Alfalfa/ Cibola Forage 0.0989 1 - - 1.10, 1.20 05-CA02 (Davis, CA/ 2005) 10 Various varieties Forage 0.0996 1 - - 2.22, 2.42 05-ID01 (Kimberly, ID/ 2005) 11 DK 140 Forage 0.0953 1 - - 1.50, 1.59 05-WA01 (Prosser, WA/ 2005) 11 Alfalfa/ Perfect A1 Forage 0.0975 1 - - 0.820, 0.960
04-CO09 (Fort Collins, CO /2004) 8 Alfalfa/ Focus Hay 0.0972 1 - - 6.61, 6.16 04-ID04 (Kimberly, ID /2004) 11 Alfalfa/ Rampage Hay 0.1043 1 - - 5.82, 9.07 04-WA09 (Prosser, WA /2004) 11 Alfalfa/ Perfect A1 Hay 0.0956 1 - - 5.49, 4.93 04-CA100 (Holtville, CA/ 2005) 10 Alfalfa/ Cibola Hay 0.0962 1 - - 4.17, 4.65 05-CA01 (Holtville, CA/ 2005) 10 Alfalfa/ Cibola Hay 0.0989 1 - - 3.34, 3.58 05-CO01 (Fort Collins, CO /2005) 8 Alfalfa/ Focus Hay 0.0972 1 - - 8.28, 8.04 05-CA02 (Davis, CA/ 2005) 10 Various varieties per plot Hay 0.0996 1 - - 5.40, 5.04Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 31 of 43 05-ID01 (Kimberly, ID/ 2005) 11 Alfalfa/DK 140 Hay 0.0953 1 - - 4.34, 4.54 05-WA01 (Prosser, WA/ 2005) 11 Alfalfa/ Perfect A1 Hay 0.0975 1 - - 2.61, 3.18
05-CA01 (Holtville, CA/ 2005) 10 Alfalfa/ Cibola Seed 0.0989 1 - - 0.19, 0.070 04-CA100 (Holtville, CA/ 2005) 10 Alfalfa/ Cibola Seed 0.0962 1 - - 0.270, 0.420 05-CO01 (Fort Collins, CO /2005) 8 Alfalfa/ Focus Seed 0.0972 1 - - 0.430, 0.430 05-ID01 (Kimberly, ID/ 2005) 11 Alfalfa/DK 140 Seed 0.0953 1 - - 0.160, 0.160 05-WA01 (Prosser, WA/ 2005) 11 Alfalfa/ Perfect A1 Seed 0.0975 1 - - 0.056, 0.079

1 Samples were not analyzed for the metabolites CPU, and PCA.
2 Residues were found to increase from the firs t to the third cutting at trial site CO09. Therefore, the forage and hay samples from the third cutting were the only samples analyzed in the remaining trials (except for the firs t forage cutting in the 05-CO01 trial).

TABLE A.2.2. Alfalfa: Residue Data from Crop Field Trials with Diflubenzuron. Trial ID (City, State/ Year) Zone Crop/ Variety Commodity or Matrix TRT # Total Rate (lb ai/A) PHI (days) Diflubenzuron (ppm) CPU (ppm) CPA (ppm) Combined Residues

(ppm) 1

CA147 (Holtville, CA/ 2011) 10 Alfalfa/ CUF 101 Forage 02 0.1290 1 2.57 <0.005 <0.005 2.58 2 2.37 <0.005 <0.005 2.38 2 1.99 <0.005 <0.005 2.00 3 2.44 <0.005 <0.005 2.45 3 5.73 <0.005 <0.005 5.74 4 1.44 <0.005 <0.005 1.45 4

03 0.3808 1 4.24 <0.005 <0.005 4.25 2 5.15 <0.005 <0.005 5.16 2 4.05 <0.005 <0.005 4.06 3 3.75 <0.005 <0.005 3.76 3 11.6 <0.005 <0.005 11.61 4 7.77 <0.005 <0.005 7.78 4

ID17 (Kimberly, ID/ 2011) 11 Alfalfa/ Sundance Forage 02 0.1016 1 0.76 <0.005 <0.005 0.77 2 0.74 <0.005 <0.005 0.75 2 1.15 <0.005 <0.005 1.16 3 1.61 <0.005 <0.005 1.62 3 <0.05 <0.005 <0.005 0.06 4 1.67 <0.005 <0.005 1.68 4

03 0.2907 1 1.53 <0.005 <0.005 1.54 2 1.95 <0.005 <0.005 1.96 2 2.66 <0.005 <0.005 2.67 3 2.31 <0.005 <0.005 2.32 3 3.39 <0.005 <0.005 3.40 4 3.57 <0.005 <0.005 3.58 4

WA*33 (Moxee, WA/ 2011) 11 Alfalfa/ Ranger Forage 02 0.0978 1 <0.05 <0.005 <0.005 0.06 2 <0.05 <0.005 <0.005 0.06 2 0.67 <0.005 <0.005 0.68 3 1.09 <0.005 <0.005 1.10 3 1.22 <0.005 <0.005 1.23 4 1.77 <0.005 <0.005 1.78 4

03 0.2896 1 <0.05 <0.005 <0.005 0.06 2 <0.05 <0.005 <0.005 0.06 2 3.18 <0.005 <0.005 3.19 3 4.40 <0.005 <0.005 4.41 3 4.92 <0.005 <0.005 4.93 4 6.05 <0.005 <0.005 6.06 4
CA147 (Holtville, CA/ 10 Alfalfa/ CUF 101 Hay 02 0.1290 1 5.41 <0.005 <0.005 5.42 2 6.66 <0.005 <0.005 6.67 2Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 32 of 43 TABLE A.2.2. Alfalfa: Residue Data from Crop Field Trials with Diflubenzuron. Trial ID (City, State/ Year) Zone Crop/ Variety Commodity or Matrix TRT # Total Rate (lb ai/A) PHI (days) Diflubenzuron (ppm) CPU (ppm) CPA (ppm) Combined Residues

(ppm) 1 2011) 5.95 <0.005 <0.005 5.96 3 7.32 <0.005 <0.005 7.33 3 15.6 0.105 <0.005 15.71 4 10.8 0.0595 <0.005 10.86 4

03 0.3808 1 13.5 <0.005 <0.005 13.51 2 13.0 <0.005 <0.005 13.01 2 9.49 <0.005 <0.005 9.50 3 11.5 <0.005 <0.005 11.51 3 45.0 0.144 <0.005 45.15 4 36.9 0.124 0.0056 37.03 4

ID17 (Kimberly, ID/ 2011) 11 Alfalfa/ Sundance Hay 02 0.1016 1 5.15 <0.005 <0.005 5.16 2 4.03 <0.005 <0.005 4.04 2 5.58 <0.005 <0.005 5.59 3 5.92 <0.005 <0.005 5.93 3 4.71 <0.005 <0.005 4.72 4 4.60 <0.005 <0.005 4.61 4

03 0.2907 1 15.5 <0.005 0.0066 15.51 2 10.9 <0.005 0.0054 10.91 2 12.0 <0.005 <0.005 12.01 3 12.3 <0.005 0.0053 12.31 3 10.1 <0.005 <0.005 10.11 4 12.3 <0.005 <0.005 12.31 4

WA*33 (Moxee, WA/ 2011) 11 Alfalfa/ Ranger Hay 02 0.0978 1 2.90 <0.005 <0.005 2.91 2 4.12 <0.005 <0.005 4.13 2 3.83 <0.005 <0.005 3.84 3 3.79 0.0053 <0.005 3.80 3 4.35 <0.005 <0.005 4.36 4 5.13 <0.005 <0.005 5.14 4

03 0.2896 1 11.00 <0.005 <0.005 11.01 2 7.50 <0.005 <0.005 7.51 2 19.10 0.0059 0.0052 19.11 3 13.90 0.0056 0.0057 13.91 3 18.60 0.0068 <0.005 18.61 4 15.60 <0.005 <0.005 15.61 4

CA147 (Holtville, CA/ 2011) 10 Alfalfa/ CUF 101 Seed 04 0.0967 1 0.23 <0.005 <0.005 0.24 0.26 <0.005 <0.005 0.27

05 0.2919 1 0.44 <0.005 <0.005 0.45 0.36 <0.005 <0.005 0.37

ID17 (Kimberly, ID/ 2011) 11 Alfalfa/ Sundance Seed 04 0.1010 1 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06

05 0.2978 1 0.079 <0.005 <0.005 0.09 0.108 <0.005 <0.005 0.12

WA*33 (Moxee, WA/ 2011) 11 Alfalfa/ Ranger Seed 04 0.0969 1 60.3 <0.005 <0.005 60.31 34.5 <0.005 <0.005 34.51

05 0.2891 1 1.10 <0.005 <0.005 1.11 2.04 <0.005 <0.005 2.05

1 For residues <0.05 and <0.005 ppm, values of 0.05 and 0.005 ppm, resp ectively, were used to calculate the sum of combined resid ues 2 First cutting. 3 Second cutting. 4 Third cutting.Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 33 of 43 TABLE A.2.3 Carrot Resi due Data from Carrot Field Trials with Diflubenzuron

Trial ID (City, State/ Year) Zone Crop/Variety Commodity or Matrix Total Rate (lb ai/A) PHI (days) Diflubenzuron (ppm) CPU (ppm) PCA (ppm) Combined Residues (ppm) 1 CA87 (Holtville, CA/2008) 10 Carrot/ Danvers 126 Root 0.25 7 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06

CA88 (Parlier, CA /2008) 10 Carrot/ Danvers 126 Root 0.253 3 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06

7 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06

10 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06

14 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06 CA*89 (Salinas, CA /2008) 10 Carrot/ Danvers 126 Root 0.251 7 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06 CA*90 (Salinas, CA /2008) 10 Carrot/ Danvers 126 Root 0.255 6 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06 GA*04 (Tifton, GA /2008) 2 Carrot/ Chantenay Red Root 0.254 6 0.0676 <0.005 <0.005 0.08 <0.05 <0.005 <0.005 0.06 GA*05 (Tifton, GA /2008) 2 Carrot/ Danvers Root 0.254 6 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06 OH*04 (Willard, OH /2008) 5 Carrot/ Maverick Root 0.243 7 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06 TX*35 (Weslaco, TX /2008) 6 Carrot/ Nikki (Nantes) Root 0.250 7 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06 WA*17 (Moxee, WA /2008) 11 Carrot/ Ya Ya 1 Root 0.247 7 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06

`TABLE A.2.4. Peach and Plum Residue Data from Crop Field Trials with Diflubenzuron.

Trial ID (City, State/Year) Zone Crop/ Variety Matrix Total Rate (lb ai/A) PHI (days) Diflubenzuron (ppm) CPU (ppm) PCA (ppm) Combined Residues 1

(ppm) AR05 (Clarksville, AR/ 2009) 4 Peach/ Crest Haven Fruit without pit 0.494 16 0.10, 0.09 <0.005 <0.005 0.11, 0.10

CA39 (Parlier, CA/2009) 10 Peach/ June Flame Fruit without pit 0.503 14 0.12, 0.09 <0.005 <0.005 0.13, 0.10

CA41 (Parlier, CA/2009) 10 Peach/ June Flame Fruit without pit 0.508 0 0.16, 0.29 <0.005 <0.005 0.17, 0.30
7 0.15, 0.12 <0.005 <0.005 0.16, 0.13
14 0.08, 0.08 <0.005 <0.005 0.09, 0.09
21 0.08, <0.05 <0.005 <0.005 0.09, 0.06 MI17 (Fennville, MI/2009) 5 Peach/ Redskin Fruit without pit 0.502 14 0.40, 0.47 <0.005 <0.005 0.41, 0.48

NC07 (Jackson Springs/2009) 2 Peach/ Contender Fruit without pit 0.504 16 0.13, 0.14 <0.005 <0.005 0.14, 0.15

NJ04 (Cream Ridge, NJ/2009) 2 Peach/ Loring Fruit without pit 0.510 15 0.09, 0.17 <0.005 <0.005 0.10, 0.18

NJ05 (Cream Ridge, NJ/2009) 2 Peach/ Suncrest Fruit without pit 0.499 14 0.26, 0.26 <0.005 <0.005 0.27, 0.27

CA38 (Gridley, CA/2009) 10 Plum/ French Fruit without pit 0.484 13 0.06, 0.09 <0.005 <0.005 0.070, 0.10

CA40 (Parlier, CA/2009) 10 Plum/ John W Fruit without pit 0.502 14 <0.05, <0.05 <0.005 <0.005 0.060, 0.060

CA42 (Parlier, CA/2009) 10 Plum/Black Splendor Fruit without pit 0.505 14 <0.05, <0.05 <0.005 <0.005 0.060, 0.060Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 34 of 43 CA43 (Gridley, CA/2009) 10 Plum/ French Fruit without pit 0.484 13 0.11, 0.10 <0.005 <0.005 0.12, 0.11

Dried Fruit without pit 0.19 <0.005 <0.005 0.20

WA18 (Wapato, WA/ 2009) 11 Plum/ Late Fruit without pit 0.499 10 0.05, 0.06 <0.005 <0.005 0.060, 0.070

1 Diflubenzuron, CPU and CPA residues were determined by Smith ers Viscient Laboratory. For residues <0.05 and <0.005 ppm, values of 0.05 and 0.005 were used to determined combin ed residues of diflubenzuron + CPU + PCA

TABLE A.2.5. Peach and plum Residue Data from Crop Field Trials with Diflubenzuron. Trial ID (City, State/Year) Zone Crop/ Variety Commodity or Matrix Total Rate (lb a.i./A) PHI (days) Diflubenzuron (ppm) CPU (ppm) PCA (ppm) Combined Residues 1

(ppm) KHG-05-101 (Athens, GA/ 2005) 2 Peach/ Contender Fruit 0.504 14 0.42 <0.01 <0.005 0.44 0.17 <0.01 <0.005 0.18 0.10 <0.01 <0.005 0.11 RGC-05-201 (Orefield, PA/ 2005) 1 Peach/ Garnet Beauty Fruit 0.507 14 0.13 <0.01 <0.005 0.14 0.11 <0.01 <0.005 0.12 0.27 <0.01 <0.005 0.28 RDH-05-301 (Sultana, CA/ 2005) 10 Peach/ September

Delight Fruit 0.496 14 0.070 <0.01 <0.005 0.08 0.20 <0.01 <0.005 0.22 0.33 <0.01 <0.005 0.35 CLS-05-401 (Hughson, CA/ 2005) 10 Peach/ Fairtime Fruit 0.495 14 0.25 <0.01 <0.005 0.26 0.22 <0.01 <0.005 0.23 0.15 <0.01 <0.005 0.17 AWD-05-501 (Waller, TX/ 2005) 6 Peach/ Texas Royal Fruit 0.510 14 0.060 <0.01 <0.005 0.080 0.080 <0.01 <0.005 0.10 0.21 <0.01 <0.005 0.23 JAC-05-601 (Conklin, MI/ 2005) 5 Plum/ Stanley Fruit 0.490 14 0.15 <0.01 <0.005 0.17 0.16 <0.01 <0.005 0.17 0.19 <0.01 <0.005 0.20 CLS-05-402 (Live Oak, CA/ 2005) 10 Plum/ French Fruit 0.499 14 0.080 <0.01 <0.005 0.10 0.10 <0.01 <0.005 0.12 0.070 <0.01 <0.005 0.080 SCO-05-701 (Zillah, WA/ 2005) 12 Plum/ Italian Fruit 0.489 14 0.12 <0.01 <0.005 0.14 0.20 <0.01 0.0199 0.23 0.18 <0.01 0.02 0.21
1 For residues <0.01 and <0.005 ppm, values of 0.01 and 0.005 were used to calculate combined residues of diflubenzuron, CPU and PCA



### Attachment 3. International Residue Limit Status Sheet



## International Re sidue Limits

Diflubenzuron (PC Code 108201; Date of Request 6/16/2015) Summary of US and International Tolerances and Maximum Residue Limits Residue Definition : US Canada Mexico 2 

### Codex 3 

### 40 CFR §180.377: Plant: diflubenzuron (N -[[(4- chlorophenyl)amino]carbonyl]-2,6- difluorobenzamide) Livestock: diflubenzuron None Diflubenzuron (fatsoluble).



### Commodity 1 

### Tolerance (ppm) /Maximum Residue Limit (mg/kg)Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 35 of 43 

### Summary of US and International Tolerances and Maximum Residue Limits Residue Definition : US Canada Mexico 2 

### Codex 3 

### US Canada Mexico 2 

### Codex 3 

### Carrot, roots 0.20 Peach subgroup 12-12B 0.50 0.5 peach, nectarine 

### Plum subgroup 12-12C 0.50 0.5 plums (including prunes) 

### Nut, tree, group 14-12 0.20 0.2 tree nuts 

### Pepper/Eggplant subgroup 8-10B 1.0 3 peppers, chili 20 peppers, chili, dried 0.7 peppers, sweet 

### Carrot, roots 0.20 Alfalfa, forage 6.0 Alfalfa, hay 20 Alfalfa, seed 0.90 Cottonseed subgroup 20C 0.20

Egg 0.07 0.05 (*) 

### Poultry, fat 0.10 Poultry, meat byproducts 0.08

Completed by: M. Negussie; 06/29/15

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;Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 36 of 43 

### Attachment 4. OECD MRL Calc ulator Inputs and Results

**Diflubenzuron Alfalfa Forage** 
**PHI 1 3 applications of 0.0325 lb ai/A,last cutting** 

**Residues (mg/kg)**
3.595
0.870
1.505
1.974 **Total number of data (n)** 12
2.558 **Percentage of censored data** 0%
1.583 **Number of non-censored data** 12
2.197 **Lowest residue** 0.870
1.905 **Highest residue** 3.595
1.158 **Median residue** 1.744
2.332 **Mean** 1.845
1.559 **Standard deviation (SD)** 0.771
0.898 **Correction factor for censoring (CF)** 1.000

**Proposed MRL estimate**

**- Highest residue** 3.595
**- Mean + 4 SD** 4.928
**- CF x 3 Mean** 5.534
**Unrounded MRL** 5.534

**Rounded MRL 6**  **3 applications of 0.0325 lb ai/A,last cutting Diflubenzuron**  **Alfalfa Forage**
**PHI 1** Reset file G e Select frameDiflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 37 of 43 **Diflubenzuron Alfalfa hay** 
**PHI 1 3 applications of 0.0325 lb ai/A,last cutting** 

**Residues (mg/kg)**
13.287
4.665
4.750
6.409 **Total number of data (n)** 12
7.477 **Percentage of censored data** 0%
5.228 **Number of non-censored data** 12
8.192 **Lowest residue** 2.907
4.428 **Highest residue** 13.287
3.470 **Median residue** 4.989
5.240 **Mean** 5.876
4.461 **Standard deviation (SD)** 2.786
2.907 **Correction factor for censoring (CF)** 1.000

**Proposed MRL estimate**

**- Highest residue** 13.287
**- Mean + 4 SD** 17.021
**- CF x 3 Mean** 17.629
**Unrounded MRL** 17.629

**Rounded MRL 20**  **3 applications of 0.0325 lb ai/A,last cutting Diflubenzuron** 

**Alfalfa hay**
**PHI 1** Reset file Gener a Select frameDiflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 38 of 43 **Diflubenzuron**
**Alfalfa seed**
**PHI 1 3 applications of 0.0325 lb ai/A** 

**Residues (mg/kg)**
0.258
0.060
0.148
0.388 **Total number of data (n)** 7 0.483 **Percentage of censored data** 0%
0.180 **Number of non-censored data** 7 0.070 **Lowest residue** 0.060 **Highest residue** 0.483 **Median residue** 0.180

**Mean** 0.227 **Standard deviation (SD)** 0.160 **Correction factor for censoring (CF)** 1.000

**Proposed MRL estimate**

**- Highest residue** 0.483
**- Mean + 4 SD** 0.866
**- CF x 3 Mean** 0.680
**Unrounded MRL** 0.866

**Rounded MRL 0.9** 

High uncertainty of MRL estimate. [Small dataset] **3 applications of 0.0325 lb ai/A Diflubenzuron** 
**Alfalfa seed**
**PHI 1** Reset file G e Select frameDiflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 39 of 43 **Diflubenzuron**
**Carrot**
**PHI 7 2 applications of 0.125 lb ai/A** 

**Residues (mg/kg)**
0.060
0.060
0.060
0.060 **Total number of data (n)** 9
0.060 **Percentage of censored data** 0%
0.060 **Number of non-censored data** 9
0.070 **Lowest residue** 0.060
0.060 **Highest residue** 0.070
0.060 **Median residue** 0.060

**Mean** 0.061 **Standard deviation (SD)** 0.003 **Correction factor for censoring (CF)** 1.000

**Proposed MRL estimate**

**- Highest residue** 0.070
**- Mean + 4 SD** 0.074
**- CF x 3 Mean** 0.183
**Unrounded MRL** 0.183

**Rounded MRL 0.2**  **2 applications of 0.125 lb ai/A Diflubenzuron** 
**Carrot**
**PHI 7** Reset file G e Select frameDiflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 40 of 43 **Diflubenzuron**
**Peach**
**PHI 14 2 applications of 0.25 lb ai/A** 

**Residues (mg/kg)**
0.105
0.115
0.090
0.445 **Total number of data (n)** 12
0.145 **Percentage of censored data** 0%
0.140 **Number of non-censored data** 12
0.270 **Lowest residue** 0.090
0.243 **Highest residue** 0.445
0.180 **Median residue** 0.163
0.217 **Mean** 0.192
0.220 **Standard deviation (SD)** 0.098
0.137 **Correction factor for censoring (CF)** 1.000

**Proposed MRL estimate**

**- Highest residue** 0.445
**- Mean + 4 SD** 0.585
**- CF x 3 Mean** 0.577
**Unrounded MRL** 0.585

**Rounded MRL 0.6**  **2 applications of 0.25 lb ai/A Diflubenzuron** 
**Peach**
**PHI 14** Reset file G e Select frameDiflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 41 of 43 

### References:

DP#: 261060 Subject: PP# 8F4925. Diflubenzuron (Dimilin ® 2L, EPA Reg #400-461) on Rice. Results of Petition Method Validation (PMV). Case 289260. Submission S571149. From: G. Kramer To: R. Kumar and M. Laws Dated: 9/6/2002 MRID(s): 443993-03 & -06

DP#: 272976 Subject: Health Effects Divisi on (HED) Metabolism Assessment Review Committee (MARC) Meetings of 2/20/01 & 5/8/01. Diflubenzuro n. Residues of Concern for Cancer Risk Assessment. Chemical 108201. From: G. Kramer and G. Reddy To: Y. Donovan Dated: 5/31/2001 MRID(s): None

DP#: 272978 Subject: Diflubenzuron (DimilinTM 2L, EPA Reg #400-461) in/on Pears. Evaluation of Residue Data and Analytical Methods. From: G. Kramer To: S. Brothers and R. Forrest Dated: 4/3/2001 MRID(s): 451196-01 and -02 **Diflubenzuron**
**Plum**
**PHI 14 2 applications of 0.25 lb ai/A** 

**Residues (mg/kg)**
0.085
0.060
0.060
0.115 **Total number of data (n)** 8
0.065 **Percentage of censored data** 0%
0.180 **Number of non-censored data** 8
0.100 **Lowest residue** 0.060
0.193 **Highest residue** 0.193 **Median residue** 0.093

**Mean** 0.107 **Standard deviation (SD)** 0.053 **Correction factor for censoring (CF)** 1.000

**Proposed MRL estimate**

**- Highest residue** 0.193
**- Mean + 4 SD** 0.318
**- CF x 3 Mean** 0.322
**Unrounded MRL** 0.322

**Rounded MRL 0.4**  **2 applications of 0.25 lb ai/A Diflubenzuron** 
**Plum**
**PHI 14** Reset file G e Select frameDiflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 42 of 43 DP#: 254273 Subject: Submission of Multiresidue Method (MRM) test information for updating PAM-I, Appendix II: From: J. Rowell To: B. McMahon Dated: 3/22/1999 MRID(s): 44707401

DP#: 254275 Subject: PP# 8F4925. Multiresidue Method Testing of p-Chloroaniline and 4-Chlorophenylurea in Rice Grain and Soybeans. From: J. Rowell To: F. Griffith Dated: 3/22/1999 MRID(s): 44707401

DP#s: 253043, 253041, 244487, 251221 and 251609 Subject: PP#8F4925. Diflubenzuron (Dimilin ® 2L, EPA Reg #400-461) on Rice. Amendments of 8/19/98, 11/20/98, 12/3/98, 1/21/99, 1/27/99 & 2/3/99. Analytical Method for Metabolites, Revised Label, Additional Residue, Storage Stability and Rotational Crop Data. From: G. Kramer To: M. Johnson/A. Sibold Dated: 2/17/1999 MRIDs 44577601, 44689701-02, 44699201, 44692701, 44692703, 4469500102, and 44707401

DP#: 240107 Subject: PP#8F4925. Diflubenzuron (Dimilin ® 2L, EPA Reg #400-461) on Rice. Evaluation of Residue Data and Analytical Methods. From: G. Kramer To: T. Levine Dated: 6/23/1998 MRID(s): 44486401, 44399301 thru 44399306

DP#: 209032 Subject: Chemistry Chapte rs of the Reregistratio n Eligibility Document From: S. Knizner To: S. Jennings, K, Whitby, and L. Kutney Dated: 3/17/1995 MRID(s): None

DP#s: 205481 Subject: Diflubenzuron. Confined Rotational Crop Study. From: S. Knizner To: S. Jennings Dated: 2/1/1995 MRID(s): 43274101

DP#s: D321623 Subject: Diflubenzuron. IR-4’s Reque st To Register New Food/Feed Uses on Barley, Oats, Wheat, Brassica Leafy Greens (Crop Subgroup 5B), Turnip Greens, Eggplant, Okra, Peanut, and Pummelo. Summ ary of Analytical Ch emistry and Residue Data. PP#s 5E6965, 5E6966, and 5E6967.Diflubenzuron Summary of Analytical Chemistry and Residue Data D423328

Page 43 of 43 From: G. Kramer To: B. Madden/D. Rosenblatt Dated: 9/14/2006 MRID(s): 43274101**"'!** DiOubcnzuron/10820 l /C hcmtum Corporation/400

### ~~**-~ ~**  DACO 7.4.117.4.2 / 0PPTS 860.1500/0ECD llA 6 .3 .1. 6.J.2, 6

. 3.3 und 1111\ 8

. 3.1, 8.3.2, 8.3.3**~** ' · Crop Fie l d Trial

- Pcech nnd Plum


### Primary Evaluator

Pe er Rev i ewer

Approved 

### by

S T U D Y R E P O R TS : 

### E n viron m ental Scientist, California Department )>l))es t icidc Regulation

## ~~ 

# l<a- #p
Theresa Ratto, Ph.D.
, 

### Senior E n viro

. nmental Scientist (Specia list ), California Department of Pesticide R eg ulation D<lte: 3/10/2015

Dale:**~~te:6/l** 

### 5/2015 Thurston 

### G. Morton
, C h emist

## ~"'( HED/RABIV (750 9P) Snmitra Bose Biswas, Chemist

# ~~/b**,. ~**  HED/RABVI (7509P)**~**



### MRID No. 49399505 Roy W. Russell (2008) Dimilin 2L in Peaches and Plums: Magnitude of the Residue Study. Lab Proj ec t Number: GRL- I 2280, Study TD. 2005-005. Unpublished study prepared by 

### Chemtura Corporation. 7 I 9 

### pages.

EXEC UTI VE SUMMA R Y:



### The Interregional Research Project 

### No. 4 (IR-4) has submitted field tri al data 

### for dinubenzuron

on peach 

### and plum. Eight field t rials were conduc ted 

### i n t he 

### Un i ted States duri n g 2005 growing se'1so.n. Trials were conducted in North American Free Trade Agreement (NAFTA) Growing Zones I 0 (CA, 3 trinls), I (PA
, l trial), 2 (GA
, I trial)
, 6 (TX, I trial), -5 

### (M l, l trial), nnd 12 (WA, I trial).

A t each test location, wh i ch co n s i sted 

# or one untreated p l o t and one treated plot, two air

- blast ap plicatio n s of the test substance (Dimilin 2L) were made at 14 days re-treatment intervul (RTI) 

### at rates of 0.243-0.259 lb ni/ 

### A per 

### application Lo the treated plots. 

### An adjuvanl was added to each spray mixture. Peach a11d 

### plum raw agricultural commodity (RAC) samp les were ha r ves t ed 

### 14 days 

### after the last 

### application.

The p ea ch and plum samp l es were analyzed for res i dues of diflubenzuron, 4-chlorophcnylurea (C PU), and 4-chloroaniline ( P CA) using modified methods derived fr om, "Oimilin 25W, Dimilin 80\VG, and Dimili n 2L in Almonds: Mugnitude of Residu e Study'', Jnni ne E. Rose, Ph.D., Uniroyal Study No. RP-98003. The methods were adeq u ately validated in conjunction with the field sample 

### analyses. T he lowest leve l of method va li di1tion (LLMV) for res i due s of diflubenzuron, CPU and PCA in/on peach and p l um samples v. 1 

### erc 0.05 ppm, 0.01 ppm, and 0.005 ppm, respectively.

PMRA 

### Submission No. /DP Barcodc 0423328 /Mill D No. 

### 49399505 Pngc I of 1 0Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 

### 49399505 Page 2 of 10 

### Following two foliar applications of Dimilin 2L at rates of 0.243-0.259 lb ai/A per application and 14 days RTI, combined residues of di flubenzuron, CPU and PCA were 0.080-0.44 ppm in peaches without pits and 0.080-0.23 ppm in plums w ithout pits harvested at 14 days pre-harvest interval (PHI).

Samples of plum and peach were stored for up to 363 days before analysis. A freezer storage stability study was not conducted in conjunction with this study, however, a storage stability study for residues of diflubenz uron, CPU and PCA in/on peache s and plums was conducted in IR-4 Study Number 08644 (MRID No. 49399504).

STUDY/WAIVER ACCEPTABILITY/ DEFICIENCIES/CLARIFICATIONS :
Under the conditions and parameters used in the study, the field tria l residue data are classified as scientifically acceptable. Minor deficiencies/deviations were noted in the study reports, but none had any significant impact on the studies or their results.

The acceptability of this study fo r regulatory purposes is addressed in the forthcoming U.S. EPA Residue Chemistry Summary Do cument [DP Barcode Dxxxxxx].

COMPLIANCE:

Signed and dated Good Laboratory Practi ce (GLP), Quality Assurance and Data Confidentiality statements were provided. Th is study meets current GLP Requirements of 40 CFR Part 160, with the following deviations, whic h do not affect the conclusions presented in this report:

1. Supporting data such as weather, soil characteristics records; te st site history and cultural practices; and maintenance fertilizers and pest icide data were not collected in strict adherence to 40 CFR 160 guidelines.

2. The scale used at CLS-05-402 for obtaining fi eld sample weights was not maintained according to GLP standards.

A. BACKGROUND INFORMATION

Diflubenzuron is an insecticide/acaricide (insec t growth regulator) that behaves as a chitin inhibitor to suppress the growth of many leaf-eating larvae, mo squito larvae, aquatic midges, rust mite, boll weevil, and flies. Di flubenzuron was first registered in the United States in 1979 for use as an insecticide. The Agency issued a Registration Standard for diflubenzuron in September, 1985, (NTIS #PB86-176500). Diflubenz uron was also the subject of a Residue Chemistry Chapter dated 11/16/84, an Addendum to the Registration Standard dated 12/4/84, and a Reregistration Standard Update dated 6/21/91. The Rere gistration Eligibility Decision (RED) for diflubenzuron was issued in Augus t, 1997 (EPA 738-R-97-008). Tolerances for residues of diflubenzuron ar e established under 40 CFR §180.377 [US EPA Data EvaluationDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 

### 49399505 Page 3 of 10 

### Record (DER) 11/14/2006].

TABLE A.1. Test Compound Nomenclature.

Diflubenzuron H N

O H N

O F

F Cl

Common name Diflubenzuron Company experimental name DU 112307
IUPAC name 1-(4-chlorophenyl)-3 -(2,6-difluorobenzoyl)urea
CAS name N -[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide
CAS # 35367-38-5 End-use product/(EP) Dimilin 2L

Regulated Metabolite 

### O N H

Cl NH

2

Common name 4-chlorophenylurea (CPU)

Regulated Metabolite



### Cl NH

2

Common Name 4-chloroaniline (PCA)

TABLE A.2. Physicochemical Properties of the T echnical Grade Test Co mpound: Difl ubenzuron. Parameter Valu e Reference Melting point/range 210-230°C

(US EPA DER, 11/14/2006) pH Not available Density Not available Water solubility (25°C) 0.08 mg/L

Solvent solubility (25°C) (ppm) 6.5 x 10 3 Acetone 2 x 10 3 Acetonitrile 2.4 x 10 4 Dioxane 1.04 x 10 5 Dimethylformamide 1.2 x 10 5 Dimethylsulfoxide 1 x 10 3 Methanol 6 x 10 2 Dichloromethane Vapor pressure at 25°C 1.2x10 -4 mPA (9.0x10 -10 mmHg) Dissociation constant (pK a ) Not available Octanol/water partition coefficient Log(K OW ) 3.89Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 

### 49399505 Page 4 of 10

TABLE A.2. Physicochemical Properties of the T echnical Grade Test Co mpound: Difl ubenzuron. Parameter Valu e Reference UV/visible absorption spectrum Not availableDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 

### 49399505 Page 5 of 10 

### B. EXPERIMENTAL DESIGN

B.1. Study Site Information

TABLE B.1.1 Trial Site Conditions

.
Trial Identification (City, State/Year) Soil characteristics 1
Type %OM pH CEC meq/g KHG-05-101 (Athens, GA/2005) Clay Loam RGC-05-201 (Orefield, PA/2005) Silt Loam RDH-05-301 (Sultana, CA/2005) Loam CLS-05-401 (Hughson, CA/2005) Sandy Loam AWD-05-501 (Waller, TX/2005) Loamy Sand JAC-05-601 (Conklin, MI/2005) Loam CLS-05-402 (Live Oak, CA/2005) Sandy Loam SCO-05-701 (Zillah, WA/2005) Silt Loam

1 Not reported. These parameters are opti onal except in cases where th eir value affects the use pattern for the chemical.


### The actual temperature recordings were within average historical valu es for the residue study period, except KHG-05-101 which had slightly belo w normal temperatures. The actual rainfall average was within the historical rainfall average, except at the KHG-05-101 site, which experienced above normal rainfall. Irriga tion was used to supplement as needed.

TABLE B.1.2. Study Use Patt ern on Peach and Plum. Location (City, State/Year) Trial ID EP 1 Application Tank Mix/ Adjuvants Method/Timing Volume (GPA) 2 Rate (lb a.i./A) RTI 3 (days) Total Rate (lb a.i./A)
Peach Field Trials

(Athens, GA/2005) KHG-05-101 Dimilin 2L 1. Airblast Sprayer/ Beginning fruit coloration 94 0.253 - 0.504 Peptoil (COC) 2. Airblast Sprayer/ Continued fruit coloration 93 0.251 14
(Orefield, PA/2005) RGC-05-201 Dimilin 2L 1. Airblast Sprayer/ Early blush 66 0.255 - 0.507 Destiny (MSO) 2. Airblast Sprayer/ Firm ripe 66 0.252 14

(Sultana, CA/2005) RDH-05-301 Dimilin 2L 1. Airblast Sprayer/ Fruit about 90% final size 80 0.250 - 0.496 Crop Oil Concentrate 2. Airblast Sprayer/ Advanced fruit coloration 67 0.246 15

(Hughson, CA/2005) CLS-05-401 Dimilin 2L 1. Airblast Sprayer/ Fruit about 80% final size 75 0.247 - 0.495 Crop Oil Concentrate 2. Airblast Sprayer/ Fruit about 90% final size 76 0.248 14

(Waller, TX/2005) AWD-05-501 Dimilin 2L 1. Airblast Sprayer/ Fruit about 60% final size 61 0.259 - 0.510 Crop Oil Concentrate 2. Airblast Spra yer/Fruit final size, color change beginning 63 0.251 14

Plum Field Trials

(Conklin, MI/2005) JAC-05-601 Dimilin 2L 1. Airblast Sprayer/ Early fruit coloration 72 0.249 - 0.490 Crop Oil Concentrate 2. Airblast Sprayer/ Advanced fruit coloration 73 0.250 14Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 

### 49399505 Page 6 of 10 TABLE B.1.2. Study Use Patt ern on Peach and Plum. Location (City, State/Year) Trial ID EP 1 Application Tank Mix/ Adjuvants Method/Timing Volume (GPA) 2 Rate (lb a.i./A) RTI 3 (days) Total Rate (lb a.i./A)
(Live Oak, CA/2005) CLS-05-402 Dimilin 2L 1. Airblast Sprayer/Fruit coloring 75 0.250 - 0.499 Crop Oil Concentrate 2. Airblast Sprayer/ Advanced fruit coloration 75 0.249 14
(Zillah, WA/2005) SCO-05-701 Dimilin 2L 1. Airblast Sprayer/Green fruit 88 0.243 - 0.489 Omni Supreme (Mineral Oil) 2. Airblast Sprayer/Green fruit 90 0.246 15

1 EP = End-use Product
2 Gallons per acre
3 Retreatment Interval

TABLE B.1.3. Trial Numbers and Geographical Locations

. NAFTA Growing

Zones Peach Plum

Submitted Requested Submitted Requested Canada US Canada US 1 1 1A 2 1 3 4 5 1 5A 5B 6 1 7 7A 8 9 10 2 1 11 12 1 13 14 15 16 17 18 19 20 21 Total 5 3Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 

### 49399505 Page 7 of 10 

### B.2. Sample Handling and Preparation

Representative samples consisting of 24 individual peaches or plums were harvested 14 days after the last application. Peaches and plums were hand-picked or picked using a pole picker from several places on at least four individual trees, from the untreat ed and then the treated plots. Peaches and plums were halved and pits remove d. Samples were placed on ice immediately and transferred to freezers within four hours of ha rvesting. Samples were maintained in frozen storage before, during, and after shipment to th e analytical laboratory, until sample analysis. RAC peach and plum samples were kept in frozen storage at the field laboratories until shipment to the analytical laboratory via freezer truck. Each sample was individually homogenized with dry ice, using a Robot Coupe Vertical Batch Pro cessor and placed in separate plastic bags. The dry ice was allowed to sublime before weighing and analysis.

B.3. Analytical Methodology

Peach and Plum samples were analyzed for re sidues of diflubenzuron, CPU, and PCA by using validated modified analytical methods derived from, “Dimilin 25W, Dimilin 80WG, and Dimilin 2L in Almonds: Magnitude of Residue Study”, Ja nine E. Rose, Ph.D., Uniroyal Study No. RP98003. The methods were adequately validated in conjunction with the field sample analyses.

The diflubenzuron method utilized reverse phase high pressure liquid ch romatography (HPLC) as a separation technique. The CPU and PC A methods utilized cap illary column gas chromatography (GC) as a separation technique. Samples analyzed for diflubenzuron were subjected to organic solvent ex traction followed by solid phase ex traction clean-up. Quantitation was by HPLC and the limit of quantitation (L OQ) was 0.05 ppm. The CPU method involved organic solvent extraction followed by solid phase extraction clean-up. Quantitation was by GC with an electron capture detect or (ECD) and the LOQ was 0.01 pp m. PCA residues in peaches were extracted with dilute HCl after spiking the samples with an internal standard of 13 

### C-PCA. The acidic extract was made alkaline and then was extracted with hexane. The PCA was cleaned-up on a Florisil column and derivatized before quantita tion by GC/Mass spectrometry (MS). The LOQ for PCA was 0.005 ppm.

C. RESULTS AND DISCUSSION

The provided analytical methods were adequate for data collec tion. Recovery data for control samples fortified with diflubenzuron, CPU, and PCA and analyzed both prior to, and concurrently with, field-treated samples are su mmarized in Table C.1. Fortification levels ranged from 0.005 to 0.5 ppm. Method validation rec overies were within th e acceptable range of 70% to 120% for diflubenzuron, CPU, and PCA on p each and plum. No qua ntifiable residues of diflubenzuron, CPU or PCA were detected in untreated control peach or plum samples.

Following two foliar applications of Dimilin 2L at 14 days RTI, combined residues of diflubenzuron, CPU and PCA were 0.08-0.44 ppm in peaches and 0.08-0.23 ppm in plums harvested at 14 days PHI. Storage stability analysis was not conducted for this study (TableDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 

### 49399505 Page 8 of 10 

### C.2), but was done in IR-4 Study No. 08644 (MRID No. 49399504).

TABLE C.1. Summary of Recoveries of Diflub enzuron, CPU and PCA from Peach and Plum.

Matrix Type of Recovery Spike level (ppm) Sample size (n) Recoveries (%) Mean ± Std Dev (%) Diflubenzuron

Peach MV 0.05 7 89, 96, 103, 94, 95, 97, 88 95 ± 5 0.07 3 95, 96, 95 95 ± 1 0.10 3 89, 94, 93 92 ± 3 CR 0.05 5 71, 92, 91, 92, 71 83 ± 11 0.10 5 89, 79, 79, 82, 89 84 ± 5

Plum MV 0.05 7 98, 91, 91, 90, 107, 98, 101 97 ± 6 0.07 3 99, 102, 97 99 ± 3 0.10 3 93, 99, 94 95 ± 3 CR 0.05 2 94, 95 94 ± 1 0.10 2 89, 88 88 ± 1 CPU

Peach MV 0.01 6 73, 87, 88, 101, 86, 84 86 ± 9 0.05 3 117, 98, 89 100 ± 4 0.10 3 105, 99, 97 101 ± 14

CR 0.01 2 118, 119 118 ± 1 0.10 2 87, 86 86 ± 1

Plum MV 0.01 8 82, 108, 104, 98, 85, 81, 93, 85 92 ± 10 0.05 3 109, 93, 104 102 ± 8 0.10 3 85, 104, 97 95 ± 10

CR 0.05 2 98, 98 98 ± 0 0.10 2 77, 74 76 ± 2 PCA

Peach MV 0.005 6 109, 106, 101, 97, 97, 100 102 ± 5 0.05 3 104, 116, 94 104 ± 11 0.10 3 101, 102, 101 101 ± 1

CR 0.005 1 127 - 0.05 1 100 - 0.10 2 97 -

Plum MV 0.005 6 93, 92, 97, 102, 112, 113 102 ± 9 0.05 3 100, 105, 100 102 ± 3 0.10 3 87, 105, 109 100 ± 12 CR 0.005 2 110, 107 108 ± 2

0.10 2 94, 86 90 ± 6

TABLE C.2. Summary of Storage Conditions

. Matrix (RAC) Storage Temperature (°C) Actual Storage Duration (days) Interval of Demonstrated Storage Stability 1 (days) Peaches 217-304 Plums 331-363

1 Storage stability analysis was not conducted for this study but was conducted in a subsequent study, IR4 Study No. 08664, MRID No. 49399504.Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 

### 49399505 Page 9 of 10 TABLE C.3. Residue Data from Crop Field Trials with Diflubenzuron. Trial ID (City, State/Year) Zone Crop/ Variety Commodity or Matrix Total Rate (lb a.i./A) PHI (days) Diflubenzuron (ppm) CPU (ppm) PCA (ppm) Combined Residues 1

(ppm) KHG-05-101 (Athens, GA/ 2005) 2 Peach/ Contender Fruit 0.504 14 0.42 <0.01 <0.005 0.44 0.17 <0.01 <0.005 0.18 0.10 <0.01 <0.005 0.11 RGC-05-201 (Orefield, PA/ 2005) 1 Peach/ Garnet Beauty Fruit 0.507 14 0.13 <0.01 <0.005 0.14 0.11 <0.01 <0.005 0.12 0.27 <0.01 <0.005 0.28 RDH-05-301 (Sultana, CA/ 2005) 10 Peach/ September

Delight Fruit 0.496 14 0.070 <0.01 <0.005 0.08 0.20 <0.01 <0.005 0.22 0.33 <0.01 <0.005 0.35 CLS-05-401 (Hughson, CA/ 2005) 10 Peach/ Fairtime Fruit 0.495 14 0.25 <0.01 <0.005 0.26 0.22 <0.01 <0.005 0.23 0.15 <0.01 <0.005 0.17 AWD-05-501 (Waller, TX/ 2005) 6 Peach/ Texas Royal Fruit 0.510 14 0.060 <0.01 <0.005 0.080 0.080 <0.01 <0.005 0.10 0.21 <0.01 <0.005 0.23 JAC-05-601 (Conklin, MI/ 2005) 5 Plum/ Stanley Fruit 0.490 14 0.15 <0.01 <0.005 0.17 0.16 <0.01 <0.005 0.17 0.19 <0.01 <0.005 0.20 CLS-05-402 (Live Oak, CA/ 2005) 10 Plum/ French Fruit 0.499 14 0.080 <0.01 <0.005 0.10 0.10 <0.01 <0.005 0.12 0.070 <0.01 <0.005 0.080 SCO-05-701 (Zillah, WA/ 2005) 12 Plum/ Italian Fruit 0.489 14 0.12 <0.01 <0.005 0.14 0.20 <0.01 0.0199 0.23 0.18 <0.01 0.02 0.21
1 For residues <0.01 and <0.005 ppm, values of 0.01 and 0.005 were used to calculate combined residues of diflubenzuron, CPU and PCA

TABLE C.4. Summary of Residue Data from Crop Field Trials with Diflubenzuron.

Commodity Total Applic. Rate (lb ai/A) PHI (days) Combined (Diflubenzuron + CPU + CPA) (ppm) n Min. Max. HAFT 1 Median Mean Std. Dev. Peach 0.489-0.510 14 15 0.08 0.44 0.24 0.18 0.16 0.05 Plum 9 0.08 0.23 0.19 0.17 0.20 0.10

1 HAFT = Highest Average Field Trial

.


### D. CONCLUSION

The magnitude of the residue study of di flubenzuron on peach and plum was conducted consistent with standard agricu ltural practices according to propos ed experimental designs. The weather conditions at each site were within normal parameters during the growing season, except for KHG-05-101 which had slightly below norma l temperatures and above normal rainfall.

The analytical methods used for determini ng diflubenzuron, CPU, and PCA in/on peach and plum were validated and adequate for data co llection. Storage stability analysis was not conducted for this study, but was done in IR-4 Study Number 08644 (MRID No. 49399504). Following two foliar applications of Dimilin 2L at rates of 0.243-0.259 lb ai/A per application, with the use of an adjuvant, at 14 days RTI, combined residues of diflubenzuron, CPU and PCA were 0.08-0.44 ppm in peaches and 0.08-0.23 ppm in plums harvested at 14 days PHI.Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 

### 49399505 Page 10 of 10 

### E. REFERENCES

US EPA DER (14-Sep-2006): MRID 46609501. Corle y, J. (2005) Diflubenzuron: Magnitude of the Residue on Small Grain. Lab Proj ect Number: 08024.02-PTR01. Unpublished study prepared by Interregional Research Project No. 4 (IR-4). 800 p.

F. DOCUMENT TRACKING

RDI: T. Morton (6/20/2015) Petition Number(s): 4E8306 DP Barcode(s): D423328 PC Code: 108201

Template Version June 2005.

# -- -·--- - --- -- --- - --- - ----- ---------- -..-q**r~ "'I** **Difl1~bc11zuro~ I**  082011c.h.e m1ura**Corpo~-ntion 400**  .., 

### :- .:=: .: iij 

# a DACO 7.4.1/7 .4.2/0PP1 S 860.1500/0ECD I I A 6.3.1, 6

. 3.2, 6.3

. .i nnd III/\ S.J. I, 8.J.2, 8.3.3 Crop

·**~** Field Triul / Residue D e cline

- Alfalfa


### Primary Evaluntor

Peer Reviewer

Approved by 

### J Jesus 

## Leyva E nvir on mental Scien ti st,**e:r 1nent** 


### Theresa Ratto, 

### Ph.D., Senior 

### E nvirqnm en tal Scientist (S p ecia list ), Cal i fornia Department 

### of Pesticide 

### Regu l ation

Thurston G. Morton, 

### Chemist HED / RABIV (7509P) 

### Date: 3/ J 

### 0 / 2015

Date:

Su mitra Bose Biswas, 

### Chemist 

# l.,

.....**1~** 

# '/3.**~** HED/RABVI 

### (7509P)

### ~m.,

STU DY REPORT S :



### MRlD 

### No. 49399501. 

### William P. Barney and 

### Kathryn Homa (2013) Dif1 u benzuron: Magnitude of the Res i due 

### on Alfa! 

### fa. Lab Project Nu mb e r : 08678. Unpublished study 

### prepared by The Interregional Research Project No. 4 (IR-4), 399 pages.

EXECUT I VE SUMMA RY :



### The IR-4 

### has subm itt ed tie Id trial data for 

### di flub cnzuron on alfa lfa

. Nine fieki'trials were

. conduc t ed in 

### the 

### Un i ted States duri n g 2004 and 2005 growing seasons. T rials we r e co nducted 

### in Nor th 

### American free Trade Agreement (NA FT A) Grow in g Zones 8 (CO, 2 

### trials)
, 10 (CA
, 3 

### trials), and 11 (TD, 

### \VA, 4 

### trials). At each 

### fie l d s i te, Treatment 

### (TRT) 02 consisted 

### of three 

### applicat i ons m1d 

### three forage 

### and hay 

### samp l e 

### cu!1 in gs. One 

### app lic ation was 

### mad e I day before a 

### sample cutting (the same 

### interval was followed for t he 

### other two 

### applications and samp l e cuttings). All TRT 

### 02 applicatio n s targeted 0.0325 lb ai / A 

### TRT 03 (conducced 

### at fiye field



### s it es) cons i sted of three 

### or four (C009) 

### applications of 

### 0.0325 lb a i l A al 

### 14 ( ± I) days r ctreatmen t 

### intervals ( R Tls) with the 

### last appl ication I day before 

### collection of seed samples. At fieJcl 

### trial 08678.04 -!0 04, 

### the seco nd application was 

### made 19 days ntler 

### the fir st application. One pint 

### p e r acre of emulsi fi ed vegetable or paraffinic crop 

### oi l was 

### includ ed to aid in canopy 

### penetration and to minimize 

### water evaporation in both treatments. Al 

### field trials 1D04, WA09, CA02 and C009, 

### seed samples were not 

### co ll ected due to poor seed set. The pre

- harvest interval (Pl-II) was 

### I clay 

### fo r all trials (TRT 02 and 03)

.


### Harvested alfalfa forage
, hay nnd seed samp le s we r e analyzed for dinubenzuron with liquid chromatography/tandem mass spectroscopy (LC/!VIS/MS) us i ng a mo dified method derived fr o m "Diflubcnzuron: Magnitude o f th e Residue on Sma ll Grnin" IR-4 Study 08024, PTRL Study 

### I I 229W, Jnnine E. 

### Ro s e. The limit of 

### detection (LOD)"for this 

### method was 0.025 μg/mL 

### and the limit of qunnti t ation (LOQ) was 0.05 ppm in alfn[fo forage a nd seed, ;.mcl 

### 0.50 ppm in alfalfn hay.

PMRA Submission No. /DP Bnrcode 0423328 /MRID No

. 

### 4939950 I · Page I of 11Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Alfalfa

PMRA Submission No. /DP Barcode D423328 /MRID No. 

### 49399501 Page 2 of 11 

### Following three applications of diflubenzuron, thr ee forage and hay sample cuttings, and a PHI of 1 day, the maximum residues of diflubenz uron for TRT 02 were 2.9 ppm and 9.1 ppm in alfalfa forage and alfalfa hay, resp ectively. Residues were found to increase from the first to the third cutting at trial si te CO09. Therefore, the forage and ha y samples from the last cutting were the only samples analyzed in other trials (except for the first forage cutting in the CO01 trial).

Following three applications of diflubenzuron at 14 (±1) day intervals a nd a PHI of 1 day, the maximum residue of diflubenzuron in alfalfa se ed for TRT 03 was 0.43 ppm. No quantifiable residues (>LOQ) of diflubenzuron were detected in untreated control alfalfa forage, seed, and hay samples from all field sites. A residue decline study was not conducted.

Storage stability analysis was not conducted fo r this study, but was done in IR-4 Study Number B8678 (MRID No. 49399502).

STUDY/WAIVER ACCEPTABILITY/ DEFICIENCIES/CLARIFICATIONS :
Under the conditions and parameters used in the study, the field tria l residue data are classified as scientifically acceptable. The acceptability of this study fo r regulatory purposes is addressed in the forthcoming U.S. EPA Residue Chem istry Summary Document [DP Barcode Dxxxxxx].

COMPLIANCE:
Signed and dated Good Laboratory Practice (GLP), Quality Assurance and Data Confidentiality statements were provided. This study meet s current GLP Requirements of 40 CFR Part 160, with the following deviations, which do not aff ect the conclusions presented in this report.

1. Supporting field data such as weather/irrigation, soil characterizati on, test site history, cultural practices, maintenance fertilizer a nd pesticide data were not collected in adherence to Good Laboratory Practice Standards at all field sites.

2. Data for pH measurements of carrier wate r were not collected in adherence to Good Laboratory Practice Standa rds at all field sites except for 08678.04-WA09 and 08678.05- WA01.

3. Sample weights and scale calibration data were not collected in adherence to Good Laboratory Practice Standards at the 08678.04-ID04, 08678.04-CA100, 08678.05-CA01, 08678.05-CA02 and 0678.05-ID01 field sites.

4. Equipment maintenance records were not r ecorded in adherence to Good Laboratory Practice Standards at all field si tes except for 08678.05-CO01, 08678.05-WA01 and 08678.05-WA09.

5. In the field notebook for the 08678.04-WA09 tria l site, late entries, in part 7, pp.40, 41, and 43, scale calibrations, were not entered pr omptly as specified in the GLP standardsDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Alfalfa

PMRA Submission No. /DP Barcode D423328 /MRID No. 

### 49399501 Page 3 of 11 

### 160.130(e).

6. The GPS receiver used at the 08678.04-CO09 field site was not maintained in adherence to Good Laboratory Practice Standards.

7. At the 08678.05-CA02 field site, although percent moisture was determined for hay samples using a formula, the numbers used in the formula were not recorded.

8. The moisture meter used at the 08678.05-ID01 fi eld site was not maintained in adherence to Good Laboratory Practice Standards.

9. The test substance was characterized by Cr ompton Co. (now Chemtura Corporation), Guelph, Ontario, Canada. Therefore, the te st substance was not characterized in accordance with 160.135(a) (b), but was ch aracterized in accordance with OECD guidelines, which are accepted by EPA in a Memorandum of Understanding.

A. BACKGROUND INFORMATION

Diflubenzuron is an insecticide/acaricide (insec t growth regulator) that behaves as a chitin inhibitor to suppress the growth of many leaf-eating larvae, mo squito larvae, aquatic midges, rust mite, boll weevil, and flies. Di flubenzuron was first registered in the United States in 1979 for use as an insecticide. The Agency issued a Registration Standard for diflubenzuron in September, 1985, (NTIS #PB86-176500). Diflubenz uron was also the subject of a Residue Chemistry Chapter dated 11/16/84, an Addendum to the Registration Standard dated 12/4/84, and a Reregistration Standard Update dated 6/21/91. The Rere gistration Eligibility Decision (RED) for diflubenzuron was issued in Augus t, 1997 (EPA 738-R-97-008). Tolerances for residues of diflubenzuron ar e established under 40 CFR §180.377 [US EPA Data Evaluation Record (DER), 11/14/2006].

TABLE A.1. Test Compound Nomenclature.

Diflubenzuron H N

O H N

O F

F Cl Common name Diflubenzuron Company experimental name DU 112307 IUPAC name 1-(4-chlorophenyl)-3 -(2,6-difluorobenzoyl)urea CAS name N -[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide CAS # 35367-38-5 End-use product/(EP) 2 lb/gal FlC formula tion; Dimilin 2L (EPA Reg. No. 400-461)

Regulated Metabolite O N H

Cl NH

2Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Alfalfa

PMRA Submission No. /DP Barcode D423328 /MRID No. 

### 49399501 Page 4 of 11

Common name 4-chlorophenylurea (CPU)

Regulated Metabolite

Cl NH

2

Common Name 4-chloroaniline (PCA)

TABLE A.2. Physicochemical Properties of the T echnical Grade Test Co mpound: Difl ubenzuron. Parameter Valu e Reference Melting point/range 230-232°C

(US EPA DER, 11/14/2006) pH Not availabel Density (22°C) Not available Water solubility (25°C) 0.08 ppm

Solvent solubility (ppm at 25°C) 6.5 x 10 3 Acetone 2 x 10 3 Acetonitrile 2.4 x 10 4 Dioxane 1.04 x 10 5 Dimethylformamide 1.2 x 10 5 Dimethylsulfoxide 1 x 10 3 Methanol 6 x 10 2 Dichloromethane Vapour pressure at 25°C 1.2x10 -4 mPA (9.0x10 -10 mmHg) Dissociation constant (pK a ) Not available Octanol/water partition coefficient Log(K OW ) 3.89 UV/visible absorption spectrum Not availableDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Alfalfa

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### 49399501 Page 5 of 11 

### B. EXPERIMENTAL DESIGN

B.1. Study Site Information

TABLE B.1.1 Trial Site Conditions

.
Trial Identification (City, State/Year) Soil characteristics 1
Type %OM pH CEC meq/g 04-ID04 (Kimberly, ID/2004) Silt Loam 1.51 8.2 NR 04-CA100 (Holtville, CA/2005) Silty Clay Loam 0.70 7.8 NR 05-CA01 (Holtville, CA/2005) Silty Clay Loam 0.70 7.8 NR 05-CO01 (Fort Collins, CO/2005) Clay Loam 2.6 7.5 22-28 04-WA09 (Prosser, WA/2004) S ilty Loam 1.28 7.8 14.4 04-CO09 (Fort Collins, CO/2004) Clay Loam 2.0 7.7 NR 05-CA02 (Davis, CA/2005) Loam 1.33 7.0 27.4 05-WA01 (Prosser, WA/2005) TRT 02 Silt Loam 1.28 7.8 14.4 05-WA01 (Touchet, WA/2005) TRT 03 Silt Loam NR 2 6.6-7.8 5-10 05-ID01 (Kimberly, ID/2005) TRT 02 Silt Loam 1.55 8.1 14.1 05-ID01 (Kimberly, ID/2005) TRT 03 Silt Loam 1.9 8.1 18.7

1 OM = Organic matter, CEC = Cation-exchange capacity. These para meters are optional except in cas es where their value affects t he use pattern for the chemical.
2 Not Reported


### The actual temperature recordings were within average historical valu es for the residue study period, except for cooler temperature early in the growing season at the 08678.04-CA100 field trial. The actual rainfall average was within th e historical rainfall average, except for heavy rain and small hail at the 08678.04-CO09 field trial si te, and a few rain events, which were not normal, in early March at the 08678.04-CA100 field tr ial site. Irrigation wa s used to supplement as needed.

TABLE B.1.2 Study Use Pattern. Location (City, State/Year) Trial ID EP 1 Application Tank Mix/ Adjuvants Method/Timing Volume GPA 2 Rate (lb ai/A) RTI 3 (days) Total Rate (lb ai/A)

TRT02 (Kimberly, ID/ 2004) 04-ID04 Dimilin 2L 1. Broadcast/Early Bloom 26 0.0354 - 0.1043 Mor-Act 2. Broadcast/Early Bloom 25 0.0345 51 3. Broadcast/Early Bloom 25 0.0344 54
(Holtville, CA/ 2005) 04-CA100 Dimilin 2L 1. Broadcast/5% Open Bloom 28 0.0341 - 0.0996 Amigo Vegetable Oil Surfactant (93% Vegetable Oil) 2. Broadcast/2% Open Bloom 27 0.0331 21 3. Broadcast/5% Open Bloom 28 0.0324 23
(Holtville, CA/ 2005) 05-CA01 Dimilin 2L 1. Broadcast/5% Open Bloom 29 0.0343 - 0.0989 Amigo Vegetable Oil Surfactant (93% Vegetable Oil) 2. Broadcast/2-3% Open Bloom 27 0.0324 21 3. Broadcast/5% Open Bloom 28 0.0322 22
(Fort Collins, CO/ 2005) 05- CO01 Dimilin 2L 1. Broadcast/ Vegetative-Late Bud 26 0.0335 - 0.1000 Clean Crop Oil Concentrate 2. Broadcast/Early Bloom 25 0.0326 53 3. Broadcast/Early Bloom 26 0.0339 35
(Prosser, WA/ 2004) 04-WA09 Dimilin 2L 1. Broadcast/ Vegetative 23 0.0316 - 0.0956 Lilly Miller Superior Type

Spray Oil 2. Broadcast/Vegetative 26 0.0319 40 3. Broadcast/Vegetative 26 0.0321 44Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Alfalfa

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### 49399501 Page 6 of 11 TABLE B.1.2 Study Use Pattern. Location (City, State/Year) Trial ID EP 1 Application Tank Mix/ Adjuvants Method/Timing Volume GPA 2 Rate (lb ai/A) RTI 3 (days) Total Rate (lb ai/A)

(Fort Collins, CO /2004) 04- CO09 Dimilin 2L 1. Broadcast/ Late-Bud/Early Bloom 25 0.0321 -

0.0972 PHT Crop Oil Concentrate 2. Broadcast/Early Bloom 25 0.0322 61 3. Broadcast/Early Bloom 25 0.0329 37
(Davis, CA/ 2005) 05-CA02 Dimilin 2L 1. Broadcast/ Vegetative 28 0.0332 - 0.0996 Herbimax 2. Broadcast/Vegetative 28 0.0333 34 3. Broadcast/Vegetative 28 0.0331 43
(Prosser, WA/ 2005) 05-WA01 Dimilin 2L 1. Broadcast/Vegetative 21 0.0320 - 0.0976 Lilly Miller Superior Type

Spray Oil 2. Broadcast/Vegetative 26 0.0324 42 3. Broadcast/Vegetative 27 0.0332 35 (Kimberly, ID/ 2005) 05-ID01 Dimilin 2L 1. Broadcast/Early Bloom 25 0.0322 - 0.0962 Mor-Act 2. Broadcast/ Early Bloom 25 0.0318 35 3. Broadcast/Bloom 25 0.0322 42 TRT03

(Holtville, CA/ 2005) 04-CA100 Dimilin 2L 1. Broadcast/ Bloom 28 0.0323 -

0.0962 Amigo Vegetable Oil Surfactant (93% Vegetable Oil) 2. Broadcast/Bud, Bloom, Seed Pod 28 0.0314 14
3. Broadcast/Bud, Bloom, SeedFruiting 28 0.0325 14

(Holtville, CA/ 2005) 05-CA01 Dimilin 2L 1. Broadcast/Bloom 29 0.0335 -

0.0989 Amigo Vegetable Oil Surfactant (93% Vegetable Oil) 2. Broadcast/Bud, Bloom, Seed Pods 29 0.0326 15 3. Broadcast/Fruiting (Seed) 28 0.0328 14

(Fort Collins, CO/2005) 05-CO01 Dimilin 2L 1. Broadcast/Reproductive; past full bloom; pods present on plants 26 0.0337 -

0.0972 Clean Crop Oil Concentrate 2. Broadcast/ Reproductive; past full bloom; pods on plants 25 0.0321 14 3. Broadcast/Harvest maturity 24 0.0314 14
(Touchet, WA/ 2005) 05-WA01 Dimilin 2L 1. Broadcast/Seeding 21 0.0320 - 0.0975 Lilly Miller Superior Type

Spray Oil 2. Broadcast/Seed 26 0.0324 14 3. Broadcast/Seeded 27 0.0332 13 (Kimberly, ID/ 2005) 05-ID01 Dimilin 2L 1. Broadcast/Early Bloom 25 0.0322 - 0.0953 Mor-Act 2. Broadcast/ Early Bloom 25 0.0318 13 3. Broadcast/Bloom 25 0.0322 13

1 EP = End-use Product
2 Gallons per acreDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Alfalfa

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### 49399501 Page 7 of 11

TABLE B.1.3 Trial Numbers and Geographical Locations

NAFTA Growing Zones Alfalfa

Submitted Requested

1 1 1A 2 3 1 4 5 6 5A 5B 6 7 1 7A 8 2 9 1 10 3 1 11 4 1 12 13 14 15 16 17 18 19 20 21 Total 1 9 12

1 A total of nine field trials were conducted in EPA Regions 8, 10 and 11 because the request for this project was for a regional tolerance. Three field trials were conducted in 2004, while six field trials were conducted in 2005.Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Alfalfa

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### 49399501 Page 8 of 11 

### B.2. Sample Handling and Preparation

Representative forage samples were harvested at the field sites at the late bud to early bloom stage (first cut), and/or at early (one-tenth) bl oom stage (later cuts) [TRT 02], 1 day after each application. Duplicate forage samples were co llected from each control and treated plot. A minimum of approximately 2 pounds of alfalfa fo rage was collected per sample. Hay samples were harvested 1 day PHI from at least 12 separate areas of each plot and allowed to dry in the field to a moisture content of approximately 10-20% (89-90% dry matter). When rainy weather was expected, the hay samples were removed to a sheltered area for drying. A total of three cuttings were made to each plot. A minimum of approximately 1 pound of alfalfa hay (4-22% moisture) was collected per sample. Alfalfa seed samples were collected at 1 day PHI. At some sites, alfalfa was cut, dried, and then co mbined for seed collection. A minimum of approximately 4 ounces of alfalfa seed was collec ted per sample. This low collection weight was due to poor seed set in the field due to moist weather, lack of pollinat ors and insect damage.

Alfalfa forage, hay and seed samples were placed in labeled sample bags and held in frozen storage until shipment to the analytical laborato ry. All treated samples (forage, hay and seed) were placed in frozen storage within 2 hours of sampling, and shipped frozen by ACDS freezer truck. All samples were received intact and in frozen conditi on at the analytical laboratory (PTRL West, Inc., Hercules, CA). After inspecti on of the samples at the time of receipt, they were assigned unique laboratory numbers and placed in freezer storage at <-5°C until sample preparation and analysis. Frozen alfalfa forage and hay samples were subsampled by processing the samples into a fine consistency using a Hobart Cutter-Mixer 61 in the pr esence of dry ice. Processed samples were transferred to open double zi p-loc bags and stored in the freezer to allow the dry ice to sublime. Samples were sealed and maintained frozen until subsampling for analysis. Alfalfa seed samples were not m echanically processed prior to extraction.

B.3. Analytical Methodology

Residues of diflubenzuron in/on alfalfa forage , hay and seed were quantified by LC/MS/MS using a method derived from “Diflubenzuron: Ma gnitude of the Residue in Small Grains” by Janine Rose, Ph.D., IR-4 Study 08024, PT RL Study 1129W, July 28, 2004. Method modifications did not negatively aff ect the performance of the method.

Residues of diflubenzuron were extracted from alfalfa forage (10 grams), hay (10 grams) or seeds (5 grams) by repeatedly extracting with acetonitrile and the extr acts combined. The volume was adjusted to measurable volume and a 50% aliquot was removed for further clean-up. The extract was repeatedly partitioned with hexa ne and the combined hexane partitions were discarded. The remaining acetonitrile extract wa s roto-evaporated to dryness and reconstituted with a 2 mL acetonitrile. Th e reconstituted aceto nitrile extract was passed through a preconditioned C 18 

### -SPE cartridge for clean-up followed by additional clean-up using a Si-SPE cartridge. The solvent was evaporated and th e residue was reconstituted in acetonitrile and water. Samples were analyzed by LC/MS/MS . The LOD for this method was 0.025 ppm and the LOQ, which was taken as the lowest leve l of method validation (LLMV), was 0.05 ppm inDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Alfalfa

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### 49399501 Page 9 of 11 

### alfalfa forage and seed, and 0.5 ppm in alfalfa hay.

The method was validated prior to sample analysis using control alfalfa hay and seed fortified with diflubenzuron at 0.05-5.0 ppm. Method validation in alfalfa hay was utilized as the relevant method validation for forage.

C. RESULTS AND DISCUSSION

The provided analytical method wa s adequate for data collection. Recovery data for control samples fortified with diflubenzuron and analyzed both prior to, and concurrently with, fieldtreated samples are summarized in Table C.1. Method validation recoveri es of diflubenzuron on alfalfa hay and seed were within the acceptable range of 70% to 120%. No quantifiable residues of diflubenzuron were detected in untreated control alfalfa forage, seed, and hay samples from all field sites.

Following three applications of diflubenzuron at 0.0325 lb ai/A, three forage and hay sample cuttings, and a PHI of 1 day, the maximum resi dues of diflubenzuron were 2.89 ppm in alfalfa forage and 9.072 ppm in alfalfa hay and the maxi mum residue of diflubenzuron in alfalfa seed was 0.434 ppm. Storage stability analysis was no t conducted for this study, but was done in IR-4 Study Number B8678 (MRID No. 4 9399502). Residues of the metabolites CPU and PCA were not quantified in this study.

TABLE C.1. Summary of Concurren t and Method Recov eries of Diflubenzuron from Alfalfa. Analyte Matrix Spike Level (ppm) Sample Size (n) Recoveries (%) Mean ± Std Dev (%) Concurrent

Diflubenzuron Alfalfa Forage 0.05 4 124, 78, 66, 72 85  26 1 2 98, 101 100  2 2 8 101, 103, 98, 87, 73, 82, 92, 96 92 ± 10

Alfalfa

Hay 0.50 1 105 - 5 1 95 - 10 9 92, 88, 90, 65, 68, 83, 74, 88, 74 80 ± 10 Alfalfa

Seed 0.05 3 80, 80, 78 79 ± 1 0.5 4 96, 90, 99, 87 93 ± 5 Method Validation

Diflubenzuron Alfalfa Hay 0.5 3 91, 97, 73 87 ± 12 5.0 3 99, 101, 104 101 ± 3 Alfalfa

Seed 0.05 3 86, 86, 86 86 ± 0 0.5 3 91, 96, 91 93 ± 3

TABLE C.2. Summary of Storage Conditions

. Matrix (RAC) Storage Temperature (°C) Actual Storage Duration (days) Interval of Demonstrated Storage Stability 1 Alfalfa forage <-5°C 34-244

Alfalfa hay 38-216 Alfalfa seed 15-196

1 Storage stability analysis was not conducted for this study , but was done in IR-4 Study Number B8678 (MRID No. 49399502).Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Alfalfa

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### 49399501 Page 10 of 11 TABLE C.3. Residue Data from Crop Field Trials with Diflubenzuron.

Trial ID (City, State/Year) Zone Crop/Variety Commodity or Matrix Total Rate (lb ai/A) PHI (days) Diflubenzuron (ppm) 1

1 st cutting 2 nd cutting 3 rd cutting 04-CO09 (Fort Collins, CO /2004) 2 8 Alfalfa/ Focus Forage 0.0972 1 1.24, 1.97 1.580, 1.924 2.25, 1.67 04-ID04 (Kimberly, ID /2004) 11 Alfalfa/ Rampage Forage 0.1040 1 2.19, 2.89 04-WA09 (Prosser, WA /2004) 11 Alfalfa/ Perfect A1 Forage 0.0956 1 1.67, 1.48 05-CO01 (Fort Collins, CO /2005) 8 Alfalfa/ Focus Forage 0.1000 1 1.85, 1.43 2.31, 2.05 04-CA100 (Holtville, CA/ 2005) 10 Alfalfa/ Cibola Forage 0.0962 1 1.86, 1.93 05-CA01 (Holtville, CA/ 2005) 10 Alfalfa/ Cibola Forage 0.0989 1 1.10, 1.20 05-CA02 (Davis, CA/ 2005) 10 Various varieties Forage 0.0996 1 2.22, 2.42 05-ID01 (Kimberly, ID/ 2005) 11 DK 140 Forage 0.0953 1 1.50, 1.59 05-WA01 (Prosser, WA/ 2005) 11 Alfalfa/ Perfect A1 Forage 0.0975 1 0.820, 0.960
04-CO09 (Fort Collins, CO /2004) 8 Alfalfa/ Focus Hay 0.0972 1 - - 6.61, 6.16 04-ID04 (Kimberly, ID /2004) 11 Alfalfa/ Rampage Hay 0.1043 1 - - 5.82, 9.07 04-WA09 (Prosser, WA /2004) 11 Alfalfa/ Perfect A1 Hay 0.0956 1 - - 5.49, 4.93 04-CA100 (Holtville, CA/ 2005) 10 Alfalfa/ Cibola Hay 0.0962 1 - - 4.17, 4.65 05-CA01 (Holtville, CA/ 2005) 10 Alfalfa/ Cibola Hay 0.0989 1 - - 3.34, 3.58 05-CO01 (Fort Collins, CO /2005) 8 Alfalfa/ Focus Hay 0.0972 1 - - 8.28, 8.04 05-CA02 (Davis, CA/ 2005) 10 Various varieties per plot Hay 0.0996 1 - - 5.40, 5.04

05-ID01 (Kimberly, ID/ 2005) 11 Alfalfa/DK 140 Hay 0.0953 1 - - 4.34, 4.54 05-WA01 (Prosser, WA/ 2005) 11 Alfalfa/ Perfect A1 Hay 0.0975 1 - - 2.61, 3.18
05-CA01 (Holtville, CA/ 2005) 10 Alfalfa/ Cibola Seed 0.0989 1 - - 0.19, 0.070 04-CA100 (Holtville, CA/ 2005) 10 Alfalfa/ Cibola Seed 0.0962 1 - - 0.270, 0.420 05-CO01 (Fort Collins, CO /2005) 8 Alfalfa/ Focus Seed 0.0972 1 - - 0.430, 0.430 05-ID01 (Kimberly, ID/ 2005) 11 Alfalfa/DK 140 Seed 0.0953 1 - - 0.160, 0.160 05-WA01 (Prosser, WA/ 2005) 11 Alfalfa/ Perfect A1 Seed 0.0975 1 - - 0.056, 0.079

1 Samples were not analyzed for the metabolites CPU, and PCA.
2 Residues were found to increase from the firs t to the third cutting at trial site CO09. Therefore, the forage and hay samples from the third cutting were the only samples analyzed in the remaining trials (except for the firs t forage cutting in the 05-CO01 trial).Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Alfalfa

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### 49399501 Page 11 of 11 TABLE C.4. Summary of Residue Data from Crop Field Trials with Diflubenzuron.

Commodity Total Applic. Rate

(lb ai/A) PHI (days) Diflubenzuron (ppm) n Min. Max. HAFT 1 Median Mean Std. Dev. Alfalfa Forage 2 0.10 1 18 0.82 2.9 2.5 1.8 1.8 0.50

Alfalfa Hay 2 18 2.6 9.1 8.2 5.2 5.3 1.8 Alfalfa Seed 10 0.056 0.43 0.43 0.18 0.23 0.15

1 HAFT = Highest Average Field Trial
2 Alfalfa forage and hay 3 rd cutting



### D. CONCLUSION

The residue studies were conducte d consistent with standard agricultural practices as per proposed experimental designs. No anomalous weather events we re recorded, except for cooler temperature and a few rain events in early Marc h at the CA100 field tr ial and heavy rain and small hail at the CO09 field trial site. Thes e events had no adverse impact on the crops.

The LC/MS/MS residue analytical method used for determining diflubenzuron in/on alfalfa forage, hay and seed was validated and adequate for data collection. Storage stability analysis on frozen stored samples was not conducted for this study, but was done in IR-4 Study Number B8678 (MRID No. 49399502).
Following three foliar applications of Dimilin 2L, with the use of an emulsified vegetable or paraffinic crop oil, at a maximum seasonal rate of 0.10 lb ai/A, and a 1-day PHI, the maximum residues of diflubenzuron were: 2.9, 9.1, and 0.43 ppm on alfalfa forage (3 rd 

### cutting), hay (3 rd 

### cutting), and seed, respectively. A decline trial was not conducted and residues of the metabolites CPU and PCA were not quantified in this study.

E. REFERENCES

US EPA DER (14-Sep-2006): MRID 46609501. Corle y, J. (2005) Diflubenzuron: Magnitude of the Residue on Small Grain. Lab Proj ect Number: 08024.02-PTR01. Unpublished study prepared by Interregional Research Project No. 4 (IR-4). 800 p.

F. DOCUMENT TRACKING

RDI: T. Morton (6/20/2015) Petition Number(s): 4E8306 DP Barcode(s): D423328 PC Code: 108201

Template Version June 2005.Di nubcnzur on/ I 0820 I /Che mtura Co r vora t ion / 400 D/\CO 7.4.117.4.2/0PPTS 860.1500 / 0ECD II/\ 6.3.1. 6.3.2

. 6.3.3 and Ill/\ 8.3

. 1, 8.3.2. 8.3.3 Crop F ield Trial

- Alfalfa


### Primary Evaluato r

Peer Reviewer

Approved by

S

T U D Y R E POR TS: 

### J Jesus Leyva Environme nt al Scient i s t , California Department**"-V -"<J~**  

### The r esa Rano, Ph.D., Senior E n viro " nmcntal Scientist (Spec i alis t ), Cal ifornia Department of Pestic i de Regulation

Thurston G. Morton, Chemist Date: 3/10 / 2015

Date:

a t

e: 6/15/2015

HED/RAB I V (7509P) 

### JJ. Sum it ra Bose Biswas, Chemis t

# ~~ 

# r/J.**vv~** HED!RABVJ (7509P)

MRID 1 0. 

### 49399502 William P. Barney (20 14) Diflubenzuron: Magnitude of the Residue on Alfalfa. Lab Project Number: 

### 88678. Unpublished study prepared by The Interregional RescaJch Project No. 4 ( IR- 4). 307 page s.

EXECU TI VE SU M MA R Y:

The IR -4 has submitted field trial data for diflubcnzuron on alfalfa. Three trials were conducted in the United States or Canada encompassing Zones I 0 (CA; I trial) and 11 (ID and WA; 2 tri als) during the 2011 g rowing seaso n. A t eac h t es t l ocat i o n , diOub enz uron (Di mi lin 2L) was applied 3-4 times to alfa lfa fields as a broadcast fol i ar application to four treated plots. At the first trea t ed plo t at 

### all sites

. applicat i on rate was 0.0314

- 0.035 I lb ai / Napplication [Treatment (TRT) 02). At th e second treated plot at all sites. application rate was 0.0934 to 0

. 0982 lb ai / A/ application (TRT 03). Three applications we r e made to the other two treated plots 12-15 days apart. The application rates were 0.0317-0.0339 lb 

### ail A / application (TRT04) and 0.0940

- 0.1007 l b 

### ail A/application (TRTOS). J\n acljuvant was added to th e spray mixture for all app l icat i ons, except a t the ID I 7 field trial fo r TRT 02 and TRT 03.

At al l th e field trial s, forage and hay samp l es were h a r ves t ed I day aner each application to the TRT02 and TRT03 plots. Seed sa mple s were ha r vested I day after the las t app li cation to the TRT04 and TRT0 5 plots.

The harvested al fa ! fa 

### forage, ha y and seed sa mpl es were analyzed for r esidues of di flubenzuron, 4-chlorophenylurea (CPU)

. and 4

- chloroanil ine (PCA)

. by liquid chromatography / tandem mass spec tr oscopy (LC/ MS /MS) using modified methods der i ved from: "Dim ilin 25W, Dimilin 80WG and Dimi lin 2L in Almonds, Magnitude or the Residue Study," Author: J an ine E. Rose, D ated September 1 3. I 999. Uniroyal Study No. RP-98003. The methods were adequately

PMR/\ Submission No. / DP Barcodc 0423328 / MRID 

### No.49399502 Page I 

## or 14Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Alfalfa

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### 49399502 Page 2 of 14 

### validated in conjunction with the field sample an alyses. The lowest level of method validation (LLMV) for residues of diflubenzuron in/on alfalfa samples was 0.050 ppm and the LLMV for residues of CPU and PCA in/on alfalfa samples was 0.005 ppm. Residues of diflubenzuron from the TRT02 plot ranged from <0.05-5.73 ppm and 2.9-15.6 ppm in forage and hay samples, respectively. Resi dues of diflubenzuron from the TRT03 plot ranged from <0.05-11.6 ppm and 7.5-45 ppm in forage and hay samples, respectively. Residues of diflubenzuron in seed samples ranged from <0.05-60.3 ppm and 0.36-2.0 4 ppm in TRT04 and TRT05 plots, respectively.

Residues of CPU and PCA were < 0.005 ppm for all forage seed samples. Residues of CPU in hay ranged from <0.005-0.105 ppm (TRT02) and < 0.005-0.144 ppm (TRT03). Residues of PCA in hay were <0.005 ppm (TRT02) and <0.005-0.00664 ppm (TRT03).

The maximum storage intervals for field-treate d samples in this study were 322 days, 294, and 259 days for forage, hay and seed, respectively.

STUDY/WAIVER ACCEPTABILITY/ DEFICIENCIES/CLARIFICATIONS :
Under the conditions and parameters used in the study, the field tria l residue data are classified as scientifically acceptable. The acceptability of this study fo r regulatory purposes is addressed in the forthcoming U.S. EPA Residue Chem istry Summary Document [DP Barcode Dxxxxxx].

COMPLIANCE:
Signed and dated Good Laboratory Practice (GLP), Quality Assurance and Data Confidentiality statements were provided. This study meet s current GLP Requirements of 40 CFR Part 160, with the following deviations, which do not aff ect the conclusions presented in this report:

1. Supporting data such as weather /irrigation, soil charac terization records; test site history and cultural practices; and maintenance fertiliz ers and pesticides data were not collected in strict adherence to 40 CFR 160 guidelines.

2. At all trials the scale used for obtaining field sample weights was not maintained according to GLP standards.

3. At the ID17 and WA*33 trials the pH meter/paper used to measure acidity of carrier water was not maintained according to GLP standards.

A. BACKGROUND INFORMATION

Diflubenzuron is an insecticide/acaricide (insec t growth regulator) that behaves as a chitin inhibitor to suppress the growth of many leaf-eating larvae, mo squito larvae, aquatic midges, rust mite, boll weevil, and flies. Di flubenzuron was first registered in the United States in 1979 for use as an insecticide. The Agency issued a Registration Standard for diflubenzuron inDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Alfalfa

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### 49399502 Page 3 of 14 

### September, 1985, (NTIS #PB86-176500). Diflubenz uron was also the subject of a Residue Chemistry Chapter dated 11/16/84, an Addendum to the Registration Standard dated 12/4/84, and a Reregistration Standard Update dated 6/21/91. The Rere gistration Eligibility Decision (RED) for diflubenzuron was issued in Augus t, 1997 (EPA 738-R-97-008). Tolerances for residues of diflubenzuron ar e established under 40 CFR §180.377 [US EPA Data Evaluation Record (DER) 11/14/2006].

TABLE A.1. Test Compound Nomenclature.

Diflubenzuron H N

O H N

O F

F Cl

Common name Diflubenzuron Company experimental name DU 112307 IUPAC name 1-(4-chlorophenyl)-3 -(2,6-difluorobenzoyl)urea CAS name N -[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide CAS # 35367-38-5 End-use product/(EP) 2 lb/gal FIC formulation, Dimilin ® 2L (EPA Reg. No. 400-461)

Regulated Metabolite O N H

Cl NH

2

Common name 4-chlorophenylurea (CPU)

Regulated Metabolite

Cl NH

2

Common Name 4-chloroaniline (PCA)

TABLE A.2. Physicochemical Properties of the T echnical Grade Test Co mpound: Difl ubenzuron. Parameter Valu e Reference Melting point/range 210-230°C

(US EPA DER, 11/14/2006) pH Not available Density (22°C) Not available Water solubility (25°C) 0.08 ppm

Solvent solubility (g/L at 25°C) 6.5 x 10 3 Acetone 2 x 10 3 Acetonitrile 2.4 x 10 4 Dioxane 1.04 x 10 5 Dimethylformamide 1.2 x 10 5 Dimethylsulfoxide 1 x 10 3 Methanol 6 x 10 2 Dichloromethane Vapour pressure at 25°C 1.2x10 -4 mPA (9.0x10 -10 mmHg) Dissociation constant (pK a ) Does not dissociate Octanol/water partition coefficient Log(K OW ) 3.89 UV/visible absorption spectrum Not availableDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Alfalfa

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### 49399502 Page 4 of 14 

### B. EXPERIMENTAL DESIGN

B.1. Study Site Information

TABLE B.1.1 Trial Site Conditions

.
Trial Identification (City, State/Year) Soil characteristics 1
Type %OM pH CEC meq/g CA147 (Holtville, CA/2011) S ilty Clay Loam 0.5 8.2 26 ID17 (Kimberly, ID/2011) TRT02 and TRT03 Silt Loam 1.88 8.2 16.9 ID17 (Jerome, ID/2011) TRT04 a nd TRT05 Loam 2.13 7.7 16.4 WA*33 (Moxee, WA/2011) Sandy Loam 1.22 7.8 22.5

1 These parameters are optional except in cases where their value affects the use pattern for the chemical.


### The actual temperature recordings were within average historical valu es for the residue study period, except temperatures duri ng the WA*33 field trial were lo wer than normal. The actual rainfall average was within the historical rain fall average, except rain fall during the WA*33 field trial was higher than normal. Irrigation was used to supplement as needed.

TABLE B.1.2 Study Use Pattern.
Location (City, State/Year) Trial ID EP 1 Application Tank Mix/ Adjuvants Method/Timing Volume GPA 2 Rate (lb ai/A) RTI 3 (days) Total Rate (lb ai/A)

TRT02

(Holtville, CA/ 2011) CA147 Dimilin 2L 1. Foliar Broadcast/40% open bloom 22 0.0314 -

0.1290 Methylated Oil 2. Foliar Broadcast/5% open bloom 23 0.0321 33

3. Foliar Broadcast/5% open bloom 23 0.0330 28

4. Foliar Broadcast/1% open bloom 4 24 0.0325 28

(Kimberly, ID/ 2011) ID17 Dimilin 2L 1. Foliar Broadcast/Vegetative 25 0.0334 - 0.1016 None 2. Foliar Broadcast/Flowering 26 0.0351 47 Mor-Act (COC) 3. Foliar Broadcast/Mature 25 0.0331 45

(Moxee, WA/ 2011) WA*33 Dimilin 2L 1. Foliar Broadcast/Bloom 24 0.0327 -
0.0978 SunSpray oil 2. Foliar Broadcast/Bloom 22 0.0320 42 3. Foliar Broadcast/Bloom 23 0.0330 35
TRT03

(Holtville, CA/ 2011) CA147 Dimilin 2L 1. Foliar Broadcast/40% bloom 22 0.0934 -

0.3808 Methylated Oil 2. Foliar Broadcast/5% bloom 23 0.0959 33 3. Foliar Broadcast/5% bloom 23 0.0978 28 4. Foliar Broadcast/1% bloom 23 0.0937 78 (Kimberly, ID/ 2011) ID17 Dimilin 2L 1. Foliar Broadcast/Vegetative 25 0.0982 - 0.2907 None 2. Foliar Broadcast/Flowering 25 0.0976 47 Mor-Act (COC) 3. Foliar Broadcast/Mature 24 0.0949 45Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Alfalfa

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### 49399502 Page 5 of 14 TABLE B.1.2 Study Use Pattern.
Location (City, State/Year) Trial ID EP 1 Application Tank Mix/ Adjuvants Method/Timing Volume GPA 2 Rate (lb ai/A) RTI 3 (days) Total Rate (lb ai/A)
(Moxee, WA/ 2011) WA*33 Dimilin 2L 1. Foliar Broadcast/Bloom 24 0.0980 -
0.2896 SunSpray oil 2. Foliar Broadcast/Bloom 22 0.0949 42 3. Foliar Broadcast/Bloom 22 0.0967 35
TRT04 (Holtville, CA/ 2011) CA147 Dimilin 2L 1. Foliar Broadcast/Bloom & pod 22 0.0314 - 0.0967 Methylated Oil 2. Foliar Broadcast/ Bloom & pod 23 0.0321 14 3. Foliar Broadcast/Seed head 23 0.0330 15 (Jerome, ID/ 2011) ID17 Dimilin 2L 1. Foliar Broadcast/S eed pod fill 25 0.0334 - 0.1011 Mor-Act (COC) 2. Foliar Broadcast/Seed pod fill 26 0.0351 13 3. Foliar Broadcast/Mature 25 0.0331 12 (Moxee, WA/ 2011) WA*33 Dimilin 2L 1. Foliar Broadcast/Bloom 24 0.0327 - 0.0969 SunSpray oil 2. Foliar Broadcast/B loom/Seed 22 0.0320 15 3. Foliar Broadcast/Seed 23 0.0330 14 TRT05 (Holtville, CA/ 2011) CA147 Dimilin 2L 1. Foliar Broadcast/Bloom & pod 23 0.0954 - 0.2919 Methylated Oil 2. Foliar Broadcast/ Bloom & pod 23 0.0963 14 3. Foliar Broadcast/ Seed head 24 0.1002 15 (Jerome, ID/ 2011) ID17 Dimilin 2L 1. Foliar Broadcast/ Seed pod fill 25 0.0978 - 0.2978 Mor-Act (COC) 2. Foliar Broadcast/ Seed pod fill 26 0.1007 13 3. Foliar Broadcast/Mature 25 0.0994 12 (Moxee, WA/ 2011) WA*33 Dimilin 2L 1. Foliar Broadcast/Bloom 22 0.0940 - 0.2891 SunSpray oil 2. Foliar Broadcast/B loom/Seed 23 0.0996 15 3. Foliar Broadcast/Seed 22 0.0955 14

1 EP = End-use Product
2 Gallons per acre
3 Retreatment Interval
4 Hay samples taken after the third application were lost in a dust storm. The fourth application was made to collect a third sa mple of hayDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Alfalfa

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TABLE B.1.3 Trial Numbers and Geographical Locations

NAFTA Growing Zones Alfalfa

Submitted Requested

1 1A 2 3 4 5 5A 5B 6 7 7A 8 9 10 1 11 2 12 13 14 15 16 17 18 19 20 21 Total 3 3

1 Per a US EPA ChemSAC decision, these trials are requ ired to supplement data from PR 08678 (MRID No. 49399501)Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Alfalfa

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### B.2. Sample Handling and Preparation

Duplicate representative alfalfa forage and hay sa mples were harvested at all field trials 1 day after each application from TRT02 and TRT03 and c ontrol plots. Seed samples were harvested 1 day after the last application to TRT04 and TRT05 plots. The samples were shipped frozen to the USDA-ARS (Beltsville) analytical laboratory by ACDS freezer truck.. All samples arrived frozen and intact at the analyt ical laboratory. The samples we re checked in, ground with dry ice and stored frozen until extraction and analysis. Samples were analyzed for the parent compound, diflubenzuron, at the ARS facility. Prior to the an alysis for the metabolites, the Beltsville facility was closed by USDA-ARS, and no further wo rk was done on this study. The residue and fortified samples were transferred via ACDS freezer truck to the USDA-ARS laboratory in Tifton, Georgia, for storage and subsequently shipped to Smithers Viscient in Wareham, Massachusetts for complete residue analyses. A ll samples arrived frozen and intact and were stored frozen (generally <-20 o 

### C). The field samples were anal yzed for diflubenzuron, CPU and PCA. Storage stability samples were analyzed to ensure stability of analytes during shipping.

B.3. Analytical Methodology

Residues of diflubenzuron, CPU, and PCA in/on al falfa forage, hay and seed were quantified by LC/MS/MS using methods derived from the reference methods: “Diflubenzuron: Magnitude of the Residue in Small Grains”. Janine E. Rose, Ph.D., IR-4 Study 08024, PTRL Study 1129W, July 28, 2004, and “Dimilin 25W, Dimilin 80WG and Dimilin 2L in Almonds, Magnitude of the Residue Study”, Author: Janine E. Rose , Uniroyal Study No. RP-98003, September 13, 1999.

For analysis of diflubenzuron and CPU, 5 g of processed sample matrix was homogenized, centrifuged, and extracted three tim es with acetonitrile. The aceton itrile layers were collected and taken to a final volume of 80.0 mL with acetonitr ile. The sample was further diluted into the calibration standard range with purified regent water and/or 10 :90 acetonitrile:purified reagent water (v:v). If particles were , the sample was centrifuged at 13,000 rpm for five minutes prior to analysis by LC/MS/MS. The calculated LODs fo r diflubenzuron residues on alfalfa forage, hay and seed samples were 0.01428, 0.01726 and 0.01624 ppm, respectively. The calculated LOQs for diflubenzuron residues on alfalfa fo rage, hay and seed were 0.04283, 0.05177 and 0.04871 ppm, respectively. The calculated LODs for CPU residues on alfalfa forage, hay and seed samples were 0.00156, 0.00123 and 0.00152 ppm, respectively. The calculated LOQs for CPU residues on alfalfa forage, hay and seed were 0.00469, 0.00370 and 0.00456 ppm, respectively. The lowest level of method validation (LLM V) was 0.05 ppm for diflubenzuron and 0.005 ppm for CPU on alfalfa forage, hay and seed.

For PCA detection, 5 g of processed sample matr ix was fortified with the internal standard ( 13 

### C 6 

### )4-chloroaniline). The fortified sample was vortexed then allowed to settle with the cap off for five minutes. The sample was then extr acted with 0.1 N hydrochl oric acid solution (in purified regent water) and shaken at 60 o 

### C for 30 minutes, brought to ro om temperature in a cold water bath, then centrifuged. The supernatant wa s then filtered and the remaining pellet was extracted twice more. Both extractions were co llected and taken to a final volume of 100 mLDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Alfalfa

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### with 0.1N hydrochloric acid solu tion. The sample was further diluted into the calibration standard range with 10 mM ammonia formate soluti on (in purified reagent water). If particles were present, the sample was centrifuged at 13,000 rpm for five minutes prior to analysis by LC/MS/MS.

The calculated LODs for PCA residues on alfa lfa forage, hay and seed samples were 0.00128, 0.00096 and 0.00098 ppm, respectively. The calcula ted LOQs for PCA residues on alfalfa forage, hay and seed were 0.00385, 0.00289 and 0.00294 ppm, respectively. The LLMV was 0.005 ppm for PCA on alfalfa forage, hay and seed.

The methods were validated both prior to and conc urrently with field trial samples of alfalfa forage, hay and seed matrices fortified with diflubenzuron, CPU and PCA at 0.005-50 ppm.

C. RESULTS AND DISCUSSION

The provided analytical methods were adequate for data collec tion. Recovery data for control samples fortified with diflubenzuron, CPU, and PCA and analyzed both prior to, and concurrently with, field-treated samples are su mmarized in Table C.1. Fortification levels ranged from 0.005 to 0.5 ppm. Method validation rec overies were within th e acceptable range of 70% to 120% for diflubenzuron, CPU, and PCA on al falfa forage, alfalfa hay and alfalfa seed.

The maximum storage interval for field-treated samples in this study was 322 days for forage, 294 days for hay and 259 days for seed (Table C. 2). Storage stability samples were fortified with diflubenzuron, CPU and PCA at 0.5 ppm and 0.05 ppm respectively; and held in frozen storage under similar conditions to the field generated samples.

Diflubenzuron residues (TRT02) ranged from <0.05-5.73 ppm and 2.9-15.6 ppm in forage and hay samples, respectively. From the TRT03 plot, diflubenzuron resi dues ranged from <0.05- 11.6 ppm and 7.5-45 ppm in forage and hay samples, respectively. Residues of diflubenzuron in seed samples ranged from <0.050-60.3 and 0.360 to 2.04 ppm in the TRT04 and TRT05 plots, respectively. Residues of CPU were <0.005 ppm in all alfalfa hay and seed samples. Residues in alfalfa forage ranged from <0.005-0.105 pp m and <0.005-0.144 ppm in TRT02 and TRT03 plots, respectively. Residues of PCA were <0.005 ppm in all alfalfa forage and seed samples. Residues in alfalfa hay were <0.005 ppm for the TRT02 samples and ranged from <0.005- 0.00664 ppm for TRT03 samples (Table C.3).

TABLE C.1. Summary of Concurrent and Method Recoveri es of Diflubenzuron, CPU and PCA from Alfalfa Analyte Matrix Spike Level (ppm) Sample Size (n) Recoveries (%) Mean ± Std Dev (%) Concurrent

Diflubenzuron Alfalfa Forage 0.05 9 79, 77, 72, 72, 84, 79, 82, 79, 87 79  5 0.5 3 74, 74, 86 78  7 10 6 90, 91, 94, 102, 104, 115 99  10 15 3 101, 98, 90 96 ±  6Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Alfalfa

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TABLE C.1. Summary of Concurrent and Method Recoveri es of Diflubenzuron, CPU and PCA from Alfalfa Analyte Matrix Spike Level (ppm) Sample Size (n) Recoveries (%) Mean ± Std Dev (%)

CPU 0.005 10 93, 79, 73, 73, 72, 71, 78, 73, 76, 76 76 ± 6

0.05-0.5 8 74, 74, 84, 112, 103, 88, 90, 94 90 ± 13

PCA 0.005 10 106, 105, 116, 112, 100, 79, 105, 105, 109, 118 106 ± 11

0.05-0.5 5 103, 85, 110, 112, 84 99 ± 13

Diflubenzuron

Alfalfa Hay 0.05-0.5 11 73, 81, 79, 103, 67, 73, 78, 84, 75, 77, 101 81 ± 11

10-20 6 86, 101, 86, 97, 100, 100 95 ± 7 25-50 4 90, 85, 87, 120 96 ± 16

CPU 0.005-0.05 11 91, 104, 88, 79, 90, 94, 110, 84, 86, 75, 76 89 ± 11

0.5 5 103, 112, 86, 97, 81 96 ± 13

PCA 0.005 7 115, 105, 116, 103, 104, 113, 108 109  5

0.05-0.5 8 118, 108, 92, 93, 84, 88, 109, 120 102  14

Diflubenzuron

Alfalfa Seed 0.05 6 120, 113, 103, 81, 104, 115 106  14 0.5 2 98, 120 109  16 10 3 95, 97, 109 100  9

CPU 0.005 8 101, 96, 110, 80, 75, 77, 98, 98 92  13 0.05-0.5 4 90, 99, 100, 113 100  9

PCA 0.005 8 94, 94, 98, 101, 98, 102, 100, 120 101  8

0.05-0.5 4 84, 116, 91, 113 101  16
Method Validation

Diflubenzuron

Alfalfa Forage 0.05 3 95, 90, 98 94  4 1.0 3 95, 94, 97 95  2 10 3 95, 97, 103 98  4

CPU 0.005-0.05 6 90, 88, 96, 99, 108, 117 100  11 0.5 3 92, 93, 103 96  6

PCA 0.005 3 116, 116, 119 117  2 0.05 3 109, 112, 106 109  3 0.5 3 107, 104, 95 102  6

Diflubenzuron

Alfalfa Hay 0.05 3 84, 91, 86 87  3 1.0 3 83, 86, 82 88  1 10 3 91, 95, 88 91  4

CPU 0.005 3 93, 96, 91 93  3 0.05 3 85, 93, 94 91  3 0.5 3 82, 86, 90 86  4

PCA 0.005 3 113, 110, 104 109  5 0.05 3 115, 115, 108 112  4 0.5 3 109, 114, 106 110  4
Diflubenzuron Alfalfa 0.05 3 87, 84, 89 87  3Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Alfalfa

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TABLE C.1. Summary of Concurrent and Method Recoveri es of Diflubenzuron, CPU and PCA from Alfalfa Analyte Matrix Spike Level (ppm) Sample Size (n) Recoveries (%) Mean ± Std Dev (%) Seed 1.0 2 88, 87 88  1 10 3 86, 91, 95 91  4

PCU 0.005 3 113, 110, 104 109  5 0.05 3 115, 115, 108 112  4 0.5 3 109, 114, 106 110  4

PCA 0.005 3 98, 92, 96 95  3 0.05 3 99, 100, 98 99  1 0.5 3 92, 93, 95 93  2

TABLE C.2. Summary of Storage Conditions

. Matrix (RAC) Storage Temperature (°C) Actual Storage Duration (days) Interval of Demonstrated Storage Stability

(days) Diflubenzuron Alfalfa Forage <-20 322 306 Alfalafa Hay 294 306 Alfalfa Seed 259 307 CPU Alfalfa Forage <-20 322 300 Alfalafa Hay 294 301 Alfalfa Seed 259 302 PCA Alfalfa Forage <-20 322 300 Alfalafa Hay 292 301 Alfalfa Seed 256 303Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Alfalfa

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TABLE C.2.2 Stability of Diflubenzuron and its Metabolites in Frozen Alfalfa Forage, Hay and Seed

Matrix Analyte Spike Level (ppm) Interval of demonstrated storage stability (Days) Freshly Fortified Recoveries (%) [Average] Stored Sample Recoveries (%) [Average] Average Corrected Stored

Recovery (%)

Alfalfa Forage Diflubenzuron 0.5 306 74, 74, 86 [78] 72, 74, 70 [72] 92

CPU 0.05 300 74, 74 [74] 67, 85, 68 [73] 99

PCA 0.05 300 110 23. 21, 20 [21] 19

Alfalfa

Hay Diflubenzuron 0.5 306 75, 101 [88] 60. 53, 55 [56] 64

CPU 0.005-0.5 43 118, 118, 110, 84 [108] 56, 56, 54 [55] 51

PCA 0.05 301 120, 88 [104] 42. 32, 45 [40] 38

Alfalfa

Seed Diflubenzuron 0.5 307 120 72. 67, 73 [71] 59

CPU 0.005-0.5 43 98, 100, 113, 99 [102] 63, 71, 72 [67] 66

PCA 0.005-0.5 42 120, 116, 113, 84 [108] 38, 40, 42 [40] 37

TABLE C.3. Residue Data from Crop Field Trials with Diflubenzuron. Trial ID (City, State/ Year) Zone Crop/ Variety Commodity or Matrix TRT # Total Rate (lb ai/A) PHI (days) Diflubenzuron (ppm) CPU (ppm) CPA (ppm) Combined Residues

(ppm) 1

CA147 (Holtville, CA/ 2011) 10 Alfalfa/ CUF 101 Forage 02 0.1290 1 2.57 <0.005 <0.005 2.58 2 2.37 <0.005 <0.005 2.38 2 1.99 <0.005 <0.005 2.00 3 2.44 <0.005 <0.005 2.45 3 5.73 <0.005 <0.005 5.74 4 1.44 <0.005 <0.005 1.45 4

03 0.3808 1 4.24 <0.005 <0.005 4.25 2 5.15 <0.005 <0.005 5.16 2 4.05 <0.005 <0.005 4.06 3 3.75 <0.005 <0.005 3.76 3 11.6 <0.005 <0.005 11.61 4 7.77 <0.005 <0.005 7.78 4

ID17 (Kimberly, ID/ 2011) 11 Alfalfa/ Sundance Forage 02 0.1016 1 0.76 <0.005 <0.005 0.77 2 0.74 <0.005 <0.005 0.75 2 1.15 <0.005 <0.005 1.16 3 1.61 <0.005 <0.005 1.62 3 <0.05 <0.005 <0.005 0.06 4 1.67 <0.005 <0.005 1.68 4

03 0.2907 1 1.53 <0.005 <0.005 1.54 2 1.95 <0.005 <0.005 1.96 2 2.66 <0.005 <0.005 2.67 3 2.31 <0.005 <0.005 2.32 3 3.39 <0.005 <0.005 3.40 4 3.57 <0.005 <0.005 3.58 4 WA*33 (Moxee, WA/ 2011) 11 Alfalfa/ Ranger Forage 02 0.0978 1 <0.05 <0.005 <0.005 0.06 2 <0.05 <0.005 <0.005 0.06 2 0.67 <0.005 <0.005 0.68 3Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Alfalfa

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### 49399502 Page 12 of 14 TABLE C.3. Residue Data from Crop Field Trials with Diflubenzuron. Trial ID (City, State/ Year) Zone Crop/ Variety Commodity or Matrix TRT # Total Rate (lb ai/A) PHI (days) Diflubenzuron (ppm) CPU (ppm) CPA (ppm) Combined Residues

(ppm) 1 1.09 <0.005 <0.005 1.10 3 1.22 <0.005 <0.005 1.23 4 1.77 <0.005 <0.005 1.78 4

03 0.2896 1 <0.05 <0.005 <0.005 0.06 2 <0.05 <0.005 <0.005 0.06 2 3.18 <0.005 <0.005 3.19 3 4.40 <0.005 <0.005 4.41 3 4.92 <0.005 <0.005 4.93 4 6.05 <0.005 <0.005 6.06 4

CA147 (Holtville, CA/ 2011) 10 Alfalfa/ CUF 101 Hay 02 0.1290 1 5.41 <0.005 <0.005 5.42 2 6.66 <0.005 <0.005 6.67 2 5.95 <0.005 <0.005 5.96 3 7.32 <0.005 <0.005 7.33 3 15.6 0.105 <0.005 15.71 4 10.8 0.0595 <0.005 10.86 4

03 0.3808 1 13.5 <0.005 <0.005 13.51 2 13.0 <0.005 <0.005 13.01 2 9.49 <0.005 <0.005 9.50 3 11.5 <0.005 <0.005 11.51 3 45.0 0.144 <0.005 45.15 4 36.9 0.124 0.0056 37.03 4

ID17 (Kimberly, ID/ 2011) 11 Alfalfa/ Sundance Hay 02 0.1016 1 5.15 <0.005 <0.005 5.16 2 4.03 <0.005 <0.005 4.04 2 5.58 <0.005 <0.005 5.59 3 5.92 <0.005 <0.005 5.93 3 4.71 <0.005 <0.005 4.72 4 4.60 <0.005 <0.005 4.61 4

03 0.2907 1 15.5 <0.005 0.0066 15.51 2 10.9 <0.005 0.0054 10.91 2 12.0 <0.005 <0.005 12.01 3 12.3 <0.005 0.0053 12.31 3 10.1 <0.005 <0.005 10.11 4 12.3 <0.005 <0.005 12.31 4

WA*33 (Moxee, WA/ 2011) 11 Alfalfa/ Ranger Hay 02 0.0978 1 2.90 <0.005 <0.005 2.91 2 4.12 <0.005 <0.005 4.13 2 3.83 <0.005 <0.005 3.84 3 3.79 0.0053 <0.005 3.80 3 4.35 <0.005 <0.005 4.36 4 5.13 <0.005 <0.005 5.14 4

03 0.2896 1 11.00 <0.005 <0.005 11.01 2 7.50 <0.005 <0.005 7.51 2 19.10 0.0059 0.0052 19.11 3 13.90 0.0056 0.0057 13.91 3 18.60 0.0068 <0.005 18.61 4 15.60 <0.005 <0.005 15.61 4

CA147 (Holtville, CA/ 2011) 10 Alfalfa/ CUF 101 Seed 04 0.0967 1 0.23 <0.005 <0.005 0.24 0.26 <0.005 <0.005 0.27

05 0.2919 1 0.44 <0.005 <0.005 0.45 0.36 <0.005 <0.005 0.37 ID17 11 Alfalfa/ Seed 04 0.1010 1 <0.05 <0.005 <0.005 0.06Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Alfalfa

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### 49399502 Page 13 of 14 TABLE C.3. Residue Data from Crop Field Trials with Diflubenzuron. Trial ID (City, State/ Year) Zone Crop/ Variety Commodity or Matrix TRT # Total Rate (lb ai/A) PHI (days) Diflubenzuron (ppm) CPU (ppm) CPA (ppm) Combined Residues

(ppm) 1 (Kimberly, ID/ 2011) Sundance <0.05 <0.005 <0.005 0.06

05 0.2978 1 0.079 <0.005 <0.005 0.09 0.108 <0.005 <0.005 0.12

WA*33 (Moxee, WA/ 2011) 11 Alfalfa/ Ranger Seed 04 0.0969 1 60.3 <0.005 <0.005 60.31 34.5 <0.005 <0.005 34.51

05 0.2891 1 1.10 <0.005 <0.005 1.11 2.04 <0.005 <0.005 2.05

1 For residues <0.05 and <0.005 ppm, values of 0.05 and 0.005 ppm, resp ectively, were used to calculate the sum of combined resid ues 2 First cutting. 3 Second cutting. 4 Third cutting

TABLE C.4. Summary of Residue Data from Crop Field Trials with Diflubenzuron.

Commodity Total Applic. Rate (lb ai/A) PHI (days) Combined Residues of Diflubenzuron, CPU and PCA (ppm) 1 n Min. Max. HAFT 2 Median Mean Std. Dev. Alfalfa Forage 0.1

1 6 0.0600 5.74 3.60 1.56 1.98 1.94 0.3-0.4 3.40 11.6 9.70 6.06 7.71 4.99 Alfalfa Hay 0.1 4.36 15. 7 13.3 4.92 6.86 3.38 0.3-0.4 10.1 45.2 41.1 17.1 23.1 14.4 Alfalfa Seed 0.1 0.06 60.3 47.4 0.26 15.9 25.7 0.3 0.09 2.05 1.58 0.41 0.700 0.760

1 Residue values were from the third cutting
2 HAFT = Highest Average Field Trial.



### D. CONCLUSION

Studies were conducted consistent with sta ndard agricultural practices as per proposed experimental designs. Anomalous weather events were recorded at the WA*33, which experienced below normal temperat ure and higher than normal rain fall. These occurrences had no adverse impact on the study. An adjuvant was a dded to the spray mixtur e for all applications except ID17 for TRT 02 and TRT 03.

The LC/MS/MS residue analytical methods used for determining diflubenzuron, CPU, and PCA in/on alfalfa forage, alfalfa hay and alfalfa seed were validated and adequate for data collection. Storage stability data indicated that residues were stable under the conditions that samples were held between harvest and analysis. Following th ree foliar applications of Dimilin 2L at 0.0314- 0.0351lb ai/A and 0.0934-0.0982 lb ai/A per applica tion, the maximum combined diflubenzuron, CPU and PCA residues in/on alfalfa forage samples (3 rd 

### cutting) harvested at 1-day PHI, were 5.74 ppm and 11.6 ppm, respectively. The ma ximum combined diflubenzuron, CPU and PCA residues in/on alfalfa hay samples (3 rd 

### cutting) harvested at 1-day PHI, were 15.71 ppm and 45.15 ppm, respectively. The maximum combined diflubenzuron, CPU and PCA residues in/on alfalfa seed harvested at 1-day PHI, were 60.31 (low rate) and 2.05 (high rate).

E. REFERENCES

US EPA DER (14-Sep-2006): MRID 46609501. Corle y, J. (2005) Diflubenzuron: Magnitude ofDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial – Alfalfa

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### 49399502 Page 14 of 14 

### the Residue on Small Grain. Lab Proj ect Number: 08024.02-PTR01. Unpublished study prepared by Interregional Research Project No. 4 (IR-4). 800 p.

F. DOCUMENT TRACKING

RDI: T. Morton (6/20/2015) Petition Number(s): 4E8306 DP Barcode(s): D423328 PC Code: 108201

Template Version June 2005.Di llubc n zu r on / I 0820 I / Chemtura Corporn ti on / 400 DACO 7

. 4.1 17 .4.2 / 0PPTS 860.1500 / 0ECD ll A 6.3.1, 6.3.2, 6.3.3 and l l!A 8.3.I, 8.3.2
, 

### 8.3.3 C r op Fie l d Trial / Residue Decline

- Carrot


### Primary Evaluator

Peer Reviewer 

### J J esus Leyva Environmental Sc i en ti st, Ca l iforn i a Departme Jt:> of P esticide Regulation

# ~~ 

# r<a-#o

Theresa Ra tt o , Ph.D., Se ni o r Env ir qnmen t a l Scientist (Specialist), Califo rni a Departme n t of Pesticide Regulation Date: 3 / I 0 / 2015

Date:

Date: 6/ 

### 1 5 1 20 1 5 Approved 

### by
Thmsto n G

. Mo rt on, C h emis t HED / RABJV (7509P) S umi tra Bose Biswas, C h emist HED / RABVJ (7509P) 

# 1lf7'57r**~10·~**

STUDY REPORTS :

MRID No

. 49399503. Kennet h S

. 

### Sarnoi l (2008) Diflubenzuron: Magnitude of the Res i due on Ca rr ot. Project Nu mb er: 0 8 643

. U npub lished study prepared by The Inte rr egiona l Research Project No. 4 

### (IR-4), 245 

### pages.



### EXECUT I VE SUMMARY:

. The !R-4 has subm itt ed field tri a l data fo r diflubcnzuron on carrot. Nine field trials were

conduc t ed in the Un it ed Sta t es duri n g the 2008 growing seaso n. T ri a l s were conducted i n North Amer i can free Trade Agreeme nt (NAFT A) Growing Zones I 0 (CA
, 4 trials), 2 (GA, 2 trials), 5 (OH
, I 

### trial), 6 

### (TX, I 

### trial), and 11 

### (WA, 1 

### trial). Each trial site consisted of one untreated p l ot and one tre a t ed plot. A t each test loca ti on, two fol i a r app li cat i ons of the test substance (Oim ili n 2L) 

### were ma de a t 6-8 

### days r e

- treatment interval ( R T ! ) 

### to the tr eated plots at rates of 0 .1 19

- 0. 1 29 lb ai / A per app li cat i on for a 

### total rate of0

. 243-0.255 lb ai / A per season

. No adjuvant or addit i ve
was added t o spray mixtures 

### fo r any of the app lic at i ons

. Carrot 

### raw agr i cul tur a l commod i ty (RAC) 

### samples were harvested 6-7 

### days l:)fter th e last app li cat i o n. At the CA88 tri a l
, addi ti onal dup li cate samples we r e co ll ected at 3, 

### 10, and 14 clays afte r t he l as t application.

The harvested carrot RAC 

### samp l es were a n alyzed for r esid u es of diDubenzuron, 4-



### c hl orophc n ylurea (CPU), a nd 4

- chloroa nilin e (PCA) by liquid chromatography / tande m mass spect r oscopy (LC/MS / MS) u s in g modified m e th ods derived from : "D ifi ube n zuron : Magnitude of the R es idu e in Small Grains," Janine 

### E

. Rose, Ph.D.
, Un i royal Study No. 08024, 

### PTRL Study No. I 

### 129W, or "O imi lin 25W, Dimilin 80WG, and Dimilin 2L 

### in 

### Almonds: Magnitude of Residue Study:· Janine E

. Rose, Ph.D., Un i royal Study No

. RP

- 98003

. The methods were adequa t e l y valida t ed in co nj u n ct i on w i th the field sampk analyses. The lowest level of method

va li dat i on (LLMV ) for r esid u es of difl uben zuro n in / on carrot samples was 0

. 050 ppm and 

### 0.005 ppm for CPU a nd PCA.

PMRA Submission No. / DP Barcodc 0423328 / MRID No. 49399503 Page I o f 1 0Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Carrot

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399503 Page 2 of 10 

### Following two foliar applications of Dimilin 2L at 6-8 days RTI, combined residues of diflubenzuron, CPU and PCA were <0.06-0.08 ppm. In the declin e trial, combined residues were 0.06 ppm at pre-harvest interv als (PHIs) of 3, 7, 10 and 14 days.

A freezer storage stability study was conducted in conjunction with this study. Diflubenzuron residues were stable in/on carrots when stored frozen for up to 1114 days.

STUDY/WAIVER ACCEPTABILITY/ DEFICIENCIES/CLARIFICATIONS :
Under the conditions and parameters used in the study, the field tria l residue data are classified as scientifically acceptable. The acceptability of this study fo r regulatory purposes is addressed in the forthcoming U.S. EPA Residue Chem istry Summary Document [DP Barcode Dxxxxxx].

COMPLIANCE:

Signed and dated Good Laboratory Practice (GLP), Quality Assurance and Data Confidentiality statements were provided. This study meet s current GLP Requirements of 40 CFR Part 160, with the following deviations, which do not aff ect the conclusions presented in this report:

1. Weather/irrigation and soil charact erization at the field sites.

2. Test site history at the field sites.

3. Cultural practices dating back to harvest of the previous crop, and maintenance fertilizer and pesticide applications during the field trial year.

4. Environmental monitoring devices for test s ubstance storage in the OH*04 field trial.

5. The pH meter used to measure the acidity of the carrier in the field trials. Except in the CA*89 and CA*90 trials.

6. Residue sample weighing equipment in th e field trials, except in the OH*04 trial.

7. The reference standards for diflubenzuron and PCA were not characterized in accordance with GLP standards prior to their use at th e Smithers Viscient labor atory in this study. These standards were subsequently char acterized under GLP st andards at Smithers Viscient, and the results c onfirmed the respective puritie s claimed by the supplier.

A. BACKGROUND INFORMATION

Diflubenzuron is an insecticide/acaricide (insec t growth regulator) that behaves as a chitin inhibitor to suppress the growth of many leaf-eating larvae, mo squito larvae, aquatic midges, rust mite, boll weevil, and flies. Di flubenzuron was first registered in the United States in 1979 for use as an insecticide. The Agency issued a Registration Standard for diflubenzuron inDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Carrot

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399503 Page 3 of 10 

### September, 1985, (NTIS #PB86-176500). Diflubenz uron was also the subject of a Residue Chemistry Chapter dated 11/16/84, an Addendum to the Registration Standard dated 12/4/84, and a Reregistration Standard Update dated 6/21/91. The Rere gistration Eligibility Decision (RED) for diflubenzuron was issued in Augus t, 1997 (EPA 738-R-97-008). Tolerances for residues of diflubenzuron ar e established under 40 CFR §180.377 [US EPA Data Evaluation Record (DER), 11/14/2006].

TABLE A.1. Test Compound Nomenclature.

Diflubenzuron H N

O H N

O F

F Cl
Common name Diflubenzuron Company experimental name DU 112307
IUPAC name 1-(4-chlorophenyl)-3 -(2,6-difluorobenzoyl)urea
CAS name N -[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide
CAS # 35367-38-5 End-use product/(EP) 2 lb/gal FIC formulation; Dimilin ® 2L (EPA Reg. No. 400-461) Regulated Metabolite

O N H

Cl NH

2

Common name 4-chlorophenylurea (CPU)

Regulated Metabolite

Cl NH

2

Common Name 4-chloroaniline (PCA)

TABLE A.2. Physicochemical Properties of the T echnical Grade Test Co mpound: Difl ubenzuron. Parameter Valu e Reference Melting point/range 210-230°C

(US EPA DER, 11/14/2006) pH Not available Density (22°C) Not available Water solubility (25°C) 0.08 mg/L

Solvent solubility (25°C) (ppm) 6.5 x 10 3 Acetone 2 x 10 3 Acetonitrile 2.4 x 10 4 Dioxane 1.04 x 10 5 Dimethylformamide 1.2 x 10 5 Dimethylsulfoxide 1 x 10 3 Methanol 6 x 10 2 Dichloromethane Vapor pressure at 25°C 1.2x10 -4 mPA (9.0x10 -10 mmHg) Dissociation constant (pK a ) Not available Octanol/water partition coefficient Log(K OW ) 3.89Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Carrot

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399503 Page 4 of 10

TABLE A.2. Physicochemical Properties of the T echnical Grade Test Co mpound: Difl ubenzuron. Parameter Valu e Reference UV/visible absorption spectrum Not available



### B. EXPERIMENTAL DESIGN

B.1. Study Site Information

TABLE B.1.1 Trial Site Conditions

. Trial Identification (City, State/Year) Soil characteristics 1 Type %OM pH CEC (meq/g) CA87 (Holtville, CA/2008) Silty Clay Loam NR 2 7.8 25.8-26.6 CA88 (Parlier, CA/2008) Sandy Loam 0.75 6.7 7.5 CA*89 (Salinas, CA/2008) Loam 1.7 6.5 14 CA*90 (Salinas, CA/2008) Loam 1.9 7.6 18 GA*04 (Tifton, GA/2008) Sand 0.42 5.82 2.73 GA*05 (Tifton, GA/2008) Sand 0.42 5.82 2.73 OH*04 (Willard, OH/2008) Loam 63.5 5.7 42.1 TX*35 (Weslaco, TX/2008) Sandy Clay Loam 1.65 7.9 NR WA*17 (Moxee, WA/2008) Silt Loam 0.91 7.2 15.1

1 OM = Organic matter, CEC = Cation-exchange capacity. These para meters are optional except in cas es where their value affects t he use pattern for the chemical.
2 Not Reported


### The actual temperature recordings were within average historical valu es for the residue study period. The actual rainfall average was within the historical rainfall average except at GA*04 and GA*05 field trials where rainfall was below normal. Irrigation was used to supplement as needed.

TABLE B.1.2. Study Use Pattern Location (City, State/Year) Trial ID EP 1 Application Tank Mix/ Adjuvants Method/Timing Volume GPA 2 Rate (lb ai/A) RTI (days) Total Rate (lb ai/A) (Holtville, CA/2008) CA87 Dimilin 2L 1. Foliar Broadcast/Early maturity 25 0.127 - 0.25 None 2. Foliar Broadcast/Mature 24 0.123 7 (Parlier, CA/2008) CA88 Dimilin 2L 1. Foliar Broadcast/Vegetat ive 31 0.127 - 0.253 None 2. Foliar Broadcast/Vegetative 31 0.126 7

(Salinas, CA/2008) CA*89 Dimilin 2L 1. Foliar Broadcast/ 1/2-3/4” diameter roots 39 0.125 - 0.251 None

2. Foliar Broadcast/ 3/4-1” diameter roots 48 0.126 6

(Salinas, CA/2008) CA*90 Dimilin 2L 1. Foliar Broadcast/1/2-1” diameter roots 44 0.126 - 0.255 None

2. Foliar Broadcast/1/2-1” diameter roots 47 0.129 6

(Tifton, GA/2008) GA*04 Dimilin 2L 1. Foliar Broadcast/Vegetat ive 32 0.126 - 0.254 None 2. Foliar Broadcast/Vegetative 33 0.128 7 (Tifton, GA/2008) GA*05 Dimilin 2L 1. Foliar Broadcast/Vegetat ive 33 0.128 - 0.254 None 2. Foliar Broadcast/Vegetative 32 0.126 7 (Willard, OH/2008) OH*04 Dimilin 2L 1. Foliar Broadcast/Vegetat ive 22 0.124 - 0.243 None 2. Foliar Broadcast/Vegetative 22 0.119 7 (Weslaco, TX/2008) Dimilin 1. Foliar Broa dcast/Roots Forming 39 0.126 - 0.250 NoneDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Carrot

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399503 Page 5 of 10 TABLE B.1.2. Study Use Pattern Location (City, State/Year) Trial ID EP 1 Application Tank Mix/ Adjuvants Method/Timing Volume GPA 2 Rate (lb ai/A) RTI (days) Total Rate (lb ai/A) TX*35 2L 2. Foliar Broadcast/Roots Formed 39 0.124 7 (Moxee, WA/2008) WA*17 Dimilin 2L 1. Foliar Broadcast/Vegetat ive 40 0.124 - 0.247 None 2. Foliar Broadcast/Vegetative 40 0.123 8

1 EP = End-use Product
2 GPA = Gallons per acre TABLE B.1.3. Trial Numbers and Geographical Locations
NAFTA Growing Zones Carrot

Submitted Requested Canada US 1 1A 2 2 1 3 1 4 5 1 1 5A 5B 6 1 1 7 7A 8 9 10 4 4 11 1 1 12 13 14 15 16 17 18 19 20 21 Total 9 8

1 Region 2 trials in this study were conducted in s outhern Georgia, near the border with Region 3.Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Carrot

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399503 Page 6 of 10 

### B.2. Sample Handling and Preparation

Representative carrot RAC samples were harvested at all field trials 6-7 days after the last application. Duplicate carrot samples were collec ted from each control and treated plot. Tops were removed in the field and soil was shaken an d lightly brushed off from the roots. At the CA*89 and CA*90 field sites, soil was washed off by rinsing the roots in cool water. Damaged roots were discarded. The samples were shi pped frozen to the USDA-ARS (Beltsville, MD) analytical laboratory either by AC DS freezer truck or overnight air express packed in dry ice. All samples arrived frozen and int act at the analytical laborator y. The samples were checked in, ground with dry ice and stored frozen until extrac tion and analysis. Samples were analyzed for the parent compound, diflubenzuron, at the Beltsville, ARS facility. Prior to the analysis for the metabolites, the Beltsville facility was clos ed by USDA-ARS, and no further work was done on this study. The residue and fortified samples we re transferred via ACDS freezer truck to the USDA-ARS laboratory in Tifton, Georgia, for storage and subsequently shipped by ACDS freezer truck to Smithers Viscient laboratory, Ware ham, MA for complete residue analyses. All samples arrived frozen and intact and were stored frozen (generally <-20 o 

### C).

B.3. Analytical Methodology

Residues of diflubenzuron, CPU, and PCA in/ on carrot were quantified by LC/MS/MS using methods derived from “Diflubenzuron: Magnitude of the Residue in Small Grains”, Janine E. Rose, Ph.D., Uniroyal Study No. 08024, PTRL St udy No. 1129W, or “Dimilin 25W, Dimilin 80WG, and Dimilin 2L in Almonds: Magnitude of Residue Study”, Janine E. Rose, Ph.D., Uniroyal Study No. RP-98003, September 13, 1999.

For analysis of diflubenzuron and CPU, the sample was homogenized, centrifuged, and then extracted three times using acetonitrile as the ex traction solvent. The acet onitrile layers were collected and taken to a final volume of 80.0 mL with acetonitrile. For 4-chorophenyl urea, the sample was dried using a gentle stream of nitr ogen, vortexed for 30 seconds after the addition of an aliquot of 10:90 acetonitrile:purified reagent wate r (v:v) and sonicated for five minutes. The sample was further diluted into the calibration st andard range with purifie d reagent water. If particles were present, the sample was centr ifuged at 13,000 rpm for five minutes prior to analysis by LC/MS/MS. The calculated limit of detection (LOD) and limit of quantitation (LOQ) for diflubenzuron residues in/on carrot RAC samples were 0.01040 ppm and 0.03120 ppm, respectively. The calculated LOD and LO Q for CPU residues in/on carrot RAC samples were 0.00128 ppm and 0.00384 ppm, respectively. Th e LLMV for residues of diflubenzuron and CPU in/on carrot samples were 0.05 ppm and 0.005 ppm, respectively.

The processed sample matrix was fortified with the internal standard ([ 13 

### C 6 

### ]4-chloroaniline) for analysis of PCA. The sample was vortexed then allowed to settle with the cap off for five minutes. Residues were extracted using 0.1N hydr ochloric acid soluti on (in purified reagent water) and shaken at 60 °C for 30 minutes, brought to room temperature in a cold water bath, then centrifuged. The supernatant was then filt ered and the remaining pellet was extracted twice more. Both extractions were collected and taken to a final volume of 100 mL with 0.1N hydrochloric acid solution. Resi dues were analyzed by LC/MS/MS. The calculated LOD andDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Carrot

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399503 Page 7 of 10 

### LOQ for PCA residues in/on carrot RAC samples were 0.00294 ppm and 0.00883 ppm, respectively. The LLMV for residues of PCA in/on carrot samples was 0.005 ppm.
The methods were validated prior to sample analys is using control carrot samples fortified with diflubenzuron, CPU or PCA at 0.005-0.5 ppm.

C. RESULTS AND DISCUSSION

The provided analytical methods we re adequate for data collecti on. Recovery data for control samples fortified with diflubenzuron, CPU, and PCA and analyzed both prior to, and concurrently with, field-treated samples are su mmarized in Table C.1. Fortification levels ranged from 0.005 to 0.5 ppm. Method validation r ecoveries fell within the acceptable range of 70% to 120% for diflubenzuron, CPU, and PCA on carrot. No interferences were noted in control samples.

The maximum storage intervals for field-trea ted samples in this study were 1248 days for diflubenzuron and CPU and 1263 days for PCA (Tab le C.2). Storage stability samples were separately fortified with diflubenzuron ( 0.5 ppm), CPU (0.05 ppm) and PCA (0.05 ppm) soon after the receipt of the samples by the Beltsvill e analytical laboratory. The storage stability samples were held in frozen storage under sim ilar conditions to the field generated samples. The data indicates that diflubenzuron and CPU were stable under the conditions which the samples were held between harv est and analysis, but PCA may ha ve degraded by approximately 90%. The consistency of the stability result s for PCA suggests the possibility that the fortifications may have been made at 10% of the reported level (Table C.2.2).

Following two foliar applications of Dimilin 2L at 6-8 days RTI, combined residues of diflubenzuron, CPU and PCA were 0.06-0.08 ppm. In the decline tr ial, combined residues were 0.06 ppm at PHIs of 3, 7, 10 and 14 days. Resi dues of diflubenzuron (0.0676 ppm) were found in one sample harvested from the GA*04 trial at 6- 7 days after the last ap plication. In all other trials, the residue levels of di flubenzuron, CPU and PCA were <LLMV. In the decline trial, no residues above the LOQ for the analytes were fo und, so no inferences can be drawn regarding the degradation of diflubenzuron and its metabolites (Table C.3).Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Carrot

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399503 Page 8 of 10

TABLE C.1. Summary of Concurren t and Method Recov eries of Diflubenzuron from Carrot Analyte Matrix Spike Level (ppm) Sample Size (n) Recoveries (%) Mean ± Std Dev (%) Concurrent

Diflubenzuron

Carrot 0.05-0.5 11 85, 90, 93, 100, 100, 102, 103, 104, 105, 106, 109 100  7

CPU 0.005-0.05 11 91, 92, 94, 98, 112, 105, 107, 107, 111, 111, 115 104  9

PCA 1 0.005-0.05 17 45, 47, 98, 99, 105, 105, 106, 107, 108, 109, 109, 111, 111, 112, 112, 113, 116 101  21

Method Validation Diflubenzuron
Carrot 0.05-0.5 6 92, 93, 94, 98, 103, 103 97  5 CPU 0.005-0.05 6 92, 93, 98, 102, 106, 103, 99  6 PCA 0.005-0.05 6 107, 107, 111, 111, 114, 116 111  4

1 45% and 47% recoveries were describe d as being most likely the result of a “processing/fortification error”

TABLE C.2. Summary of Storage Conditions Matrix (RAC) Storage Temperature (°C) Actual Storage Duration (days) Interval of Demonstrated Storage Stability (days)

Carrot <-20 1248-1263 1108-1129

TABLE C.2.2 Stability of Diflubenzuron a nd its Metabolites in Frozen Carrot

Matrix Analyte Spike Level (ppm) Storage Interval (Days) Freshly Fortified Recoveries (%) [Average] Stored Sample Recoveries (%) [Average] Average Corrected Stored Recovery (%) 1

Carrot (Roots) Diflubenzuron 0.5 1242-1248 102, 109 [106] 91, 95, 104 [97] 92

CPU 0.05 1242-1248 107, 111 [109] 101, 107, 107, 88, 109, 113 [104] 95

PCA 1 0.05 1255-1263 98, 99, 105 [101] 12, 10, 10, 8, 7, 8 [9] 9

1 The consistency of the stability results for PCA suggests the possibility that the fortifications may have been made at 10% of the reported level.

TABLE C.3. Residue Data from Carrot Field Trials with Diflubenzuron

Trial ID (City, State/ Year) Zone Crop/Variety Commodity or Matrix Total Rate (lb ai/A) PHI (days) Diflubenzuron (ppm) CPU (ppm) PCA (ppm) Combined Residues (ppm) 1 CA87 (Holtville, CA/2008) 10 Carrot/ Danvers 126 Root 0.25 7 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06

CA88 (Parlier, CA /2008) 10 Carrot/ Danvers 126 Root 0.253 3 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06

7 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06

10 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06

14 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06 CA*89 (Salinas, CA /2008) 10 Carrot/ Danvers 126 Root 0.251 7 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06 CA*90 (Salinas, CA /2008) 10 Carrot/ Danvers 126 Root 0.255 6 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Carrot

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399503 Page 9 of 10 TABLE C.3. Residue Data from Carrot Field Trials with Diflubenzuron

Trial ID (City, State/ Year) Zone Crop/Variety Commodity or Matrix Total Rate (lb ai/A) PHI (days) Diflubenzuron (ppm) CPU (ppm) PCA (ppm) Combined Residues (ppm) 1 GA*04 (Tifton, GA /2008) 2 Carrot/ Chantenay Red Root 0.254 6 0.0676 <0.005 <0.005 0.08 <0.05 <0.005 <0.005 0.06 GA*05 (Tifton, GA /2008) 2 Carrot/ Danvers Root 0.254 6 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06 OH*04 (Willard, OH /2008) 5 Carrot/ Maverick Root 0.243 7 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06 TX*35 (Weslaco, TX /2008) 6 Carrot/ Nikki (Nantes) Root 0.250 7 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06 WA*17 (Moxee, WA /2008) 11 Carrot/ Ya Ya 1 Root 0.247 7 <0.05 <0.005 <0.005 0.06 <0.05 <0.005 <0.005 0.06

1 To determine combined residues (Diflubenzuron + CPU + PCA), resi dues <0.05 ppm and <0.005 ppm were assigned values of 0.05 ppm and 0.005 ppm, respectively.
TABLE C.4. Summary of Residue Data from Crop Field Trials with Diflubenzuron

Commodity Total Applic. Rate (lb ai/A) PHI (days) Combined Residues (Diflubenzuron + CPU + PCA) [ppm]

n Min. Max. HAFT 1 Median Mean 2 Std. Dev.

Carrot 0.243-0.255 3 2 0.06 0.06 0.06 - - - 6-7 18 0.06 0.08 0.07 0.06 0.06 0.004 10 2 0.06 0.06 0.06 - - - 14 2 0.06 0.06 0.06 - - -

1 HAFT = Highest Average Field Trial



### D. CONCLUSION

Studies were conducted consistent with sta ndard agricultural practices as per proposed experimental designs. No anomalous weather events were recorded, except at the GA*04 and GA*05 sites, which experienced below normal rain fall that had no adverse impact on the study.

The LC/MS/MS residue analytical methods used for determining diflubenzuron, CPU, and PCA in/on carrot were validated and ad equate for data collection. Storag e stability data indicated that residues were stable under the c onditions that samples were held between harvest an d analysis. The maximum combined diflubenzuron, CPU and PCA residues in/on carrot samples harvested 6-7 days following two foliar a pplications of Dimilin 2L at 0.119-0.129 lb ai/A per application, without the use of an adjuvant, were 0.07 ppm. In the decline trial, no residues above the LOQ for diflubenzuron, CPU, or PCA were found, so no inferences can be drawn regarding the degradation of diflubenzuron and its metabolites.

E. REFERENCES

US EPA DER (14-Sep-2006): MRID 46609501. Corle y, J. (2005) Diflubenzuron: Magnitude of the Residue on Small Grain. Lab Proj ect Number: 08024.02-PTR01. Unpublished study prepared by Interregional Research Project No. 4 (IR-4). 800 p.

F. DOCUMENT TRACKINGDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline - Carrot

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399503 Page 10 of 10 RDI: T. Morton (6/20/2015) Petition Number(s): 4E8306 DP Barcode(s): D423328 PC Code: 108201

Template Version June 2005.

### ----·- ··- 

## ·-·--- - -

.....**J:I** DiOu b cnzur o n/I 0820 I / Chemtura Corpor a tion /4 00**~= i}'1** **i!** DACO 7.4.1 17 .4.2 / 0PPTS 860.1500 / 0ECD l lA 6.3.1
, 6.3.2, o.3

. 3 

### and I !IA 8.3.1
, S .3 .2, 8.3.3

_ Crop Fie l d Trin l/ Re si due Decline

- Pench 

### nncl Plum · · 

### Primary Evaluator 

# J" A**-- ~-""\,..** **~./"':'** 

# _ _ J Jesus Leyva ·-i

P

e er 

### Reviewer Environmental Sc i entist, Cal i fornia Department o

Theresa Rntto, Ph.D., Senior**vir~:mmental** 

### Scientist (Specialist), C a lifo rni a Dcpartmenl of 

### Pesticide Regu l ation Date: 3/ 1 0/20 I 5

Date: 6/15/20 1 5 T h urston G. Morto n , C h em i st ·

# ~~-**-··** H E D / RABIV (7509P) 

## I. Approved by

Sum i tra Bose Biswas, Ch e mi s t /

__ __ Tf__,A

## lb~ H E D / RABVI (7509P)

.

## ~,, ............

STU DY R EP ORT S:



### MRfD No. 49399504. Will i am P

. Barney (20 1 3) D i fl ub e n zuron: Magnit u de of the Residue on Peac h & 

### Plum. Lab Projec t Number: 08644. Unpubl i s h ed study prepared 

### by The fnterregio n a l Research Project Ko. 4 (IR-4). 364 pages.

EXECUT I VE SUMMARY:



### The IR-4 has submitt e d field trial da1a for ditlubenzuron on peach and plum. Twelve field trials

. were conduc t ed in t h e Uni1cd States durLng 

### 2009 g rowLng season. Trials were conducted in North American Free 

### Trade Agreeme n t (NArT A) 

### Growing Zones l 0 

### (CA, 6 

### trials), 2 (NC and 

### NJ, 3 tri a l s), 4 (A R
, I 1 r i a l ) 1 

### 5 

### (M l
, I tr i al)
, and J 

### I (WA, 1 

### t rial).

l\L 

### each test locAtion, which consisted of one un t rea t ed plot nnd one treated plot, t wo air-blast applications of the te s t substance (Di mil in 2 L) were made post bloom 13- 1 5 days re-treatment interval (RTJ) at rates o f 0.235-0

. 259 lb ai l 

### A per applkation to
· the tre a t e d plots. An adjuvant

was added to 

### each s p ray mix t ure. Peach and plum raw agricultural commodity (RAC ) samp l es
were harvested I 0-16 d ays after the last applic a tion. At the CA4 I trial
, duplicate s amples were · collected 0, 7 and 2 J 

### dnys nfter t he last application. At the CA43 trial
, dup l ica t e samples of lreated 

### and untreated plums harvested 13 

### clays after the last app li cation**wen~** 

### co l lected 

### at1er dryi n g.



### Peach and plum samp l es were ana l yzed for residues of diflubenzuron, 4-ch!orophenylurea (CPU), and 4-chloroanilinc (PCA) by liquid ch r omatography / tandem ma s s spectroscopy (LC / MS/MS) using a modified method derived from
, "Dimilin 25W
, Dimilin 80WG
, and D i milin 2L in Almonds: Magnitude of Residue Study", Janine E. Rose, Ph.D., Uniroynl Study N o. RP

- 98003

. The m e thod 

### was adequately validated In c o njunction w ith the fie l d sample

an a l yses. The lowest l e vel of method validalion (LLMV) for residues of diflubcnzuron in/on peach and plum sample s was 0.05 ppm and 0.005 ppm for CPU and**~CA.**

PMRA Submission No. /DP Barcode 0423328 /MRID No. 49399504 Pnge I of l 2Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399504 Page 2 of 12 

### Following two foliar applications of Dimilin 2L at 14 days RTI, combined residues of diflubenzuron, CPU and PCA were 0.060-0.48 ppm in peaches wit hout pits harvested at 14-16 days pre-harvest interval (P HI) and 0.060-0.12 ppm in plums w ithout pits harvested at 10-14 days PHI. Combined residues of diflubenzur on, CPU and PCA in dried plums were 0.20 ppm. In the decline trial, combined residues decl ined from 0.24 ppm at 0-day PHI to 0.08 ppm at 21- days PHI.

A freezer storage stability study was conducted in c onjunction with this study. Samples of plum and peach were stored for up to 911 days before analysis.

STUDY/WAIVER ACCEPTABILITY/ DEFICIENCIES/CLARIFICATIONS :
Under the conditions and parameters used in the study, the field tria l residue data are classified as scientifically acceptable. The acceptability of this study fo r regulatory purposes is addressed in the forthcoming U.S. EPA Residue Chemis try Summary Document [DP Barcode Dxxxxxx].

COMPLIANCE:

Signed and dated Good Laboratory Practice (GLP), Quality Assurance and Data Confidentiality statements were provided. This study meet s current GLP Requirements of 40 CFR Part 160, with the following deviations, which do not aff ect the conclusions presented in this report:

1. Supporting data such as weather/ irrigation, soil characteristics records; test site history and cultural practices; and maintenance fertilizer s and pesticide data were not collected in strict adherence to 40 CFR 160 guidelines.

2. At all trails except NC07 and WA18, the scal e used for obtaining field sample weights was not maintained according to GLP standards.

3. At NJ04 and NJ05 field trials the test substance was received and logged in before facility SOPs were in place.

4. The reference standards diflubenzuron and 4- chloroaniline were us ed in the study for method validation prior to th eir GLP characterization.

5. The test substance and 4-chlorophenylurea reference substance was characterized by Chemtura Canada Co./Cie, Guelph Tec hnology Centre, PO Box 1120, 120 Huron St. , Guelph, Ontario, Canada. Therefore, the te st substance was not characterized in accordance with 160.135 (a) (b), but was ch aracterized in accordance with OECD guidelines, which are accepted by US EP A in a Memorandum of Understanding.Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399504 Page 3 of 12 

### A. BACKGROUND INFORMATION

Diflubenzuron is an insecticide/acaricide (insec t growth regulator) that behaves as a chitin inhibitor to suppress the growth of many leaf-eating larvae, mo squito larvae, aquatic midges, rust mite, boll weevil, and flies. Di flubenzuron was first registered in the United States in 1979 for use as an insecticide. The Agency issued a Registration Standard for diflubenzuron in September, 1985, (NTIS #PB86-176500). Diflubenz uron was also the subject of a Residue Chemistry Chapter dated 11/16/84, an Addendum to the Registration Standard dated 12/4/84, and a Reregistration Standard Update dated 6/21/91. The Rere gistration Eligibility Decision (RED) for diflubenzuron was issued in Augus t, 1997 (EPA 738-R-97-008). Tolerances for residues of diflubenzuron ar e established under 40 CFR §180.377 [US EPA Data Evaluation Record (DER) 11/14/2006].

TABLE A.1. Test Compound Nomenclature.

Diflubenzuron H N

O H N

O F

F Cl

Common name Diflubenzuron Company experimental name DU 112307
IUPAC name 1-(4-chlorophenyl)-3 -(2,6-difluorobenzoyl)urea
CAS name N -[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide
CAS # 35367-38-5 End-use product/(EP) Dimilin 2L Regulated Metabolite



### O N H

Cl NH

2

Common name 4-chlorophenylurea (CPU)

Regulated Metabolite



### Cl NH

2

Common Name 4-chloroaniline (PCA)Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399504 Page 4 of 12

TABLE A.2. Physicochemical Properties of the T echnical Grade Test Co mpound: Difl ubenzuron. Parameter Valu e Reference Melting point/range 210-230°C (US EPA DER, 11/14/2006) pH Not available Density Not available Water solubility (25°C) 0.08 mg/L Solvent solubility (25°C) (ppm) 6.5 x 10 3 Acetone 2 x 10 3 Acetonitrile 2.4 x 10 4 Dioxane 1.04 x 10 5 Dimethylformamide 1.2 x 10 5 Dimethylsulfoxide 1 x 10 3 Methanol 6 x 10 2 Dichloromethane Vapor pressure at 25°C 1.2x10 -4 mPA (9.0x10 -10 mmHg) Dissociation constant (pK a ) Not available Octanol/water partition coefficient Log(K OW ) 3.89 UV/visible absorption spectrum Not available



### B. EXPERIMENTAL DESIGN

B.1. Study Site Information

TABLE B.1.1 Trial Site Conditions

. Trial Identification (City, State/Year) Soil characteristics 1 Type %OM pH CEC (meq/g) AR05 (Clarksville, AR/2009) Silt Loam - 6.4 9 CA38 (Gridley, CA/2009) Loam 1.89 6.1 26.4 CA39 (Parlier, CA/2009) Fine Sandy Loam 0.75 6.7 7.5 CA40 (Parlier, CA/2009) Fine Sandy Loam 0.75 6.7 7.5 CA41 (Parlier, CA/2009) Fine Sandy Loam 0.75 6.7 7.5 CA42 (Parlier, CA/2009) Fine Sandy Loam 0.75 6.7 7.5 CA43 (Gridley, CA/2009) Loam 2.14 5.6 24.8 MI17 (Fennville, MI/2009) Loamy Sand 1.2 5 4.4 NC07 (Jackson Springs/2009) Sand 2.1 6.9 5.2 NJ04 (Cream Ridge, NJ/2009) Sandy Loam 2.8 5.1 13.6 NJ05 (Cream Ridge, NJ/2009) Sandy Loam 2.2 5.4 12.1 WA18 (Wapato, WA/2009) Sandy Cl ay Loam 5.35 5.46 4.28

1 OM = Organic matter, CEC = Cation-exchange capacity. These para meters are optional except in cas es where their value affects t he use pattern for the chemical.


### The actual temperature recordings and rainfall aver age were within average historical values for the residue study period, except at the NJ04 and NJ05 field sites, where temperature and rainfall varied. Irrigation was used to supplement as needed.Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399504 Page 5 of 12 TABLE B.1.2 Study Use Pattern. Location (City, State/ Year) Trial ID EP 1 Application Tank Mix/ Adjuvants Method/Timing Volume (Gallons/A) Rate (lb ai/A) RTI (days) Total Rate (lb ai/A) (Clarksville, AR/ 2009) AR05 2 Dimilin 2L 1. Airblast/Fruiting 127 0.235 - 0.494 Agri-Dex 2. Airblast/Fruiting 116 0.259 14 (Gridley, CA/ 2009) CA38 3 Dimilin 2L 1. Airblast/Fruiting 98 0.243 - 0.484 Crop Oil 2. Airblast/Fruiting 97 0.241 14 (Parlier, CA/ 2009) CA39 2 Dimilin 2L 1. Airblast/Fruiting 146 0.252 - 0.503 Agri-Dex 2. Airblast/Fruiting 146 0.251 14 (Parlier, CA/ 2009) CA40 3 Dimilin 2L 1. Airblast/Fruiting 80 0.250 - 0.502 Agri-Dex 2. Airblast/Fruiting 81 0.252 14 (Parlier, CA/ 2009) CA41 2 Dimilin 2L 1. Airblast/Fruiting 63 0.256 - 0.508 Agri-Dex 2. Airblast/Fruiting 63 0.252 14 (Parlier, CA/ 2009) CA42 3 Dimilin 2L 1. Airblast/Fruiting 101 0.253 - 0.505 Agri-Dex 2. Airblast/Fruiting 101 0.252 14 (Parlier, CA/ 2009) CA43 3 Dimilin 2L 1. Airblast/Fruiting 98 0.244 - 0.484 Crop Oil 2. Airblast/Fruiting 96 0.240 14 (Fennville, MI/ 2009) MI17 2 Dimilin 2L 1. Airblast/Fruiting 102 0.252 - 0.502 Damoil 2. Airblast/Fruiting 101 0.250 15 (Jackson Springs /2009) NC07 2 Dimilin 2L 1. Airblast/Early Fruiting 81 0.252 - 0.504 Herbimax 2. Airblast/Fruiting 80 0.252 14 (Cream Ridge, NJ/2009) NJ04 2 Dimilin 2L 1. Airblast/Fruiting 132 0.257 - 0.510 Agri-Dex 2. Airblast/Fruiting 120 0.253 13 Cream Ridge, NJ/2009) NJ05 2 Dimilin 2L 1. Airblast/Fruiting 119 0.250 - 0.499 Agri-Dex 2. Airblast/Fruiting 121 0.249 14 (Wapato, WA/ 2009) WA18 3 Dimilin 2L 1. Airblast/Fruiting 124 0.248 - 0.499 JMS Stylet-Oil 2. Airblast/Fruiting 126 0.251 14

1 EP = End-use Product
2 Peach field trials
3 Plum field trialsDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399504 Page 6 of 12 TABLE B.1.3. Trial Numbers and Geographical Locations

. NAFTA Growing Zones Peach Plum

Submitted Requested 1 Submitted Requested 1 Canada US Canada US 1 1 1A 2 3 4 3 4 1 1 5 1 1 1 5A 5B 6 1 7 7A 8 9 10 2 4 4 5 11 1 1 12 1 13 14 15 16 17 18 19 20 21 Total 7 12 5 8

1 The registrant conducted a study in 2005 that included 5 peach tria ls and 3 plum trials. This study completes the requirements for peach and plum.Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399504 Page 7 of 12 

### B.2. Sample Handling and Preparation

Representative samples of peach and plum were ha rvested 10-16 days after the last application at all field sites and began in the untreated control plot and ended in the tr eated plot. At the CA41 trial, additional duplicate samples were collected 0, 7, and 21 days after the last application. At the CA43 trial, duplicate samples of treated and un treated plums harvested 13 days after the last application were collected after drying. Peaches and plums were halved and pits removed. Pitted fruit were placed in sample bags and tran sported to freezers. The samples were shipped frozen to the USDA-ARS analytical laboratory in Beltsville, MD by ACDS freezer truck. All samples arrived frozen and intact at the analy tical laboratory. The samples were checked-in, ground with dry ice, and then st ored frozen. The field sample s and storage stability samples were analyzed for diflubenzuron. Due to closure of the laboratory, the samples were temporarily shipped from Beltsville, MD to the USDA-ARS laboratory in Tifton, GA fo r storage. Samples were then shipped to Smithers Viscient analytical laboratory for analysis. Samples were stored frozen (generally <-20 o 

### C). The field samples were analyzed for diflubenzuron, CPU and PCA. Storage stability samples were analyzed to en sure stability of the analytes during shipping.

B.3. Analytical Methodology

Peach and plum samples were analyzed for residues of diflubenzuron, CPU, and PCA by LC/MS/MS using a modified method derived fr om, “Dimilin 25W, Dimilin 80WG, and Dimilin 2L in Almonds: Magnitude of Residue Study”, Ja nine E. Rose, Ph.D., Uniroyal Study No. RP98003. The method was adequately validated in c onjunction with the field sample analyses.
At the Beltsville, MD laboratory, for analysis of diflubenzuron, samples of peach and plum were extracted using acetonitrile. After blending, it was decanted into a graduated cylinder, partitioned with hexane, concentrated, and cleaned up on a C 18 

### solid phase extraction (SPE) column. The residues were qua ntified by LC/MS/ MS detection.

At the Smithers Viscient laboratory, for analysis of diflubenzuron and CPU, samples of peach and plum were homogenized, centrifuged, and extr acted three times with acetonitrile. The acetonitrile layers were collected and taken to a final volume of 80 mL with acetonitrile. For CPU, subsamples of peach and plum were dried us ing a gentle stream of nitrogen, vortexed for 30 seconds after the addition of an aliquot of 10:90 acetonitrile:purified re agent water (v:v), and sonicated for five minutes. The diflubenzuron a nd CPU extracts were further diluted into the calibration standard range with pur ified reagent water. If particles were present, samples were centrifuged at 13,000 rpm for five mi nutes prior to analysis by LC/MS/MS. The calculated limit of detection (LOD) and limit of quantitation (L OQ) for diflubenzuron residues in/on peaches were 0.01442 ppm and 0.04326 ppm, respectively; 0.01521 ppm and 0.04564 ppm in plums, respectively; and 0.00795 ppm and 0.02385 ppm in dr ied plums, respectively. The calculated LOD and LOQ for CPU residues in/on peaches were 0.00114 ppm and 0.00342 ppm, respectively; and 0.00083 ppm and 0.00248 ppm in plums, respectively

. The LLMV for residues of diflubenzuron and CPU in/on peach and plum samples were 0.05 ppm and 0.005 ppm, respectively.Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399504 Page 8 of 12 

### For PCA, 5.0 g of sample matrix was used fo r the peach and plum samples with the exception that for the plum samples, the processed sample matrix was fortified with the internal standard ([ 13 

### C 6 

### ]4-chloroaniline) followed by vortexing then a llowing the sample bottle to remain open for 5 minutes. Peach and plum samples were extract ed with 0.1N hydrochloric acid and shaken at 60 °C for 30 minutes, brought to room temperatur e in a cold water bath, then centrifuged. The supernatant was then filtered and the remaini ng pellet was extracted tw ice more with 0.1N hydrochloric acid, collecting each extraction a nd taken to a final volume of 100mL with hydrochloric acid. The peach and plum sample s were further diluted into the calibration standard range with 10 mM ammonium formate in purified reagent water. The calculated LOD and LOQ for PCA residues in/on peaches were 0.00158 ppm and 0.00474 ppm, respectively and 0.00058 ppm and 0.00174 ppm in plums, respectively

. The LLMV for residues of PCA in/on peach and plum samples was 0.005 ppm.

The methods were validated prior to sample an alysis using control peach and plum samples fortified with diflubenzuron, CPU or PCA at 0.005-0.5 ppm.

C. RESULTS AND DISCUSSION

The provided analytical methods we re adequate for data collecti on. Recovery data for control samples fortified with diflubenzuron, CPU, and PCA and analyzed both prior to, and concurrently with, field-treated samples are su mmarized in Table C.1. Fortification levels ranged from 0.005 to 0.5 ppm. Method validation r ecoveries fell within the acceptable range of 70% to 120% for diflubenzuron, CPU, and PCA on p each and plum. No qua ntifiable residues of diflubenzuron, CPU or PCA were detected in untreated control peach or plum samples.

Following two foliar applications of Dimilin 2L at 14 days RTI, combined residues of diflubenzuron, CPU and PCA were 0.06-0.48 ppm in peaches harvested at 14-16 days PHI and 0.06-0.12 ppm in plums harvested at 10-14 days PHI. Combined residues of diflubenzuron, CPU and PCA in dried plum were 0.20 ppm. In the d ecline trial, combined residues declined from 0.24 ppm at 0-day PHI to 0.08 ppm at 21-days PHI.

Storage stability samples fortified with diflube nzuron at 0.5 ppm and held in frozen storage under similar conditions to the field generate d samples at the USDA -ARS laboratory in Beltsville, MD. After 452 days of freezer storag e, it was determined at Smithers-Viscient Laboratory that diflubenzuron was stable on peach, plum, and dried plum samples. Additional storage stability samples of each commodity we re fortified with 0.5 ppm diflubenzuron, and 0.05 ppm CPU and PCA at Smither s-Viscient Laboratory.Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399504 Page 9 of 12

TABLE C.1 Summary of Recoveries of Diflub enzuron, CPU and PCA from Peach and Plum. Matrix Type of Recovery 1 Spike level (ppm) Sample size (n) Recoveries (%) 2 Mean ± Std Dev (%) Diflubenzuron

Peach (without pits) MV 0.05 7 75, 71, 92, 81, 106, 108, 104 91 ± 15 0.5 7 86, 78, 88, 82, 98, 98, 97 90 ± 8

CR 0.05 11 92, 93, 109, 78, 77, 95, 93, 90, 97, 105, 94 93 ± 10

0.5 8 112, 109, 78, 81, 84, 96, 105 95 ± 14

SSCR 0.05 1 100 - 0.5 2 94, 96 95 ± 1

Plum (without pits) MV 0.05 6 83, 86, 88, 106, 111, 101 96 ± 12 0.5 6 88, 85, 85, 91, 96, 95 90 ± 5

CR 0.05 9 80, 72, 75, 114, 86, 93, 93, 100, 90 89 ± 13 0.5 5 94, 72, 91, 87, 93 87 ± 9

SSCR 0.05 2 90, 95 92 ± 4 0.5 3 104, 100, 106 103 ± 3

Dried Plum (without pits) MV 0.05 3 101, 101, 101 101 ± 0 0.5 3 77, 85, 85 82 ± 5

CR 0.05 2 102, 92 97 ± 7 0.5 4 111, 71, 107, 99 97 ± 18 SSCR 0.5 1 100 - CPU

Peach (without pits) MV 0.005 3 94, 106, 104 101 ± 6 0.05 3 95, 92, 92 93 ± 2

CR 0.005 6 85, 84, 91, 107, 92, 96 92 ± 8 0.05 3 95, 93, 114 101 ± 12

SSCR 0.005 1 97 - 0.05 1 109 -

Plum (without pits) MV 0.005 3 94, 106, 104 101 ± 6 0.05 3 95, 92, 92 93 ± 2

CR 0.005 6 85, 84, 91, 107, 92, 96 92 ± 8 0.05 3 95, 93, 114 101 ± 12

SSCR 0.005 2 87, 93 - 0.05 2 88, 92 90 ± 3 Dried Plum (without pits) CR 0.005 1 96 - SSCR 0.05 1 105 - PCA Peach (without pits) MV 0.005 3 101, 109, 111 107 ± 5 0.05 3 106, 103, 105 105 ± 2

SSCR/CR 0.005 7 117, 93, 98, 112, 120, 119,129 113 ± 13 0.05 3 114, 114 138 ± 42 Plum (without pits) MV 0.005 3 117, 116, 116 116 ± 1 0.05 3 98, 102, 101 100 ± 2

SSCR/CR 0.005 5 116, 109, 116, 106, 116 113 ± 5 0.05 1 110 - Dried Plum (without pits) SSCR/CR 0.005 1 98 -

1 MV = Method validation; CR = Concurrent recovery ; SSCR = Storage stability concurrent recovery
2 MV recoveries for diflubenzuron were from both laboratoriesDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399504 Page 10 of 12

TABLE C.2. Summary of Storage Conditions

.
Matrix (RAC) Storage Temperature (°C) Storage Stability Recoveries (%) Actual Storage Duration (days) Interval of Demonstrated Storage Stability (days) Diflubenzuron

Peach (without pits) <-20 79.8 867 740 96.2 867 740 103 867 770

Plum (without pits) <-20 97.5 875 665 98.5 875 665 104 875 695

Dried Plum (without pits) <-20 61.2 800 740 56.2 800 740 45.5 800 770 CPU

Peach (without pits) <-20 97.4 867 760 111 867 760 102 867 760 95.9 867 770 106 867 770 110 867 770

Plum (without pits) <-20 94.4 875 760 99.9 875 760 92.9 875 760 93.2 875 770 98.8 875 770 109 875 770

Dried Plum (without pits) <-20 55.9 800 685 45.2 800 685 48.9 800 685 60.2 800 695 50.8 800 695 53.8 800 695 PCA

Peach (without pits) <-20 58.2 903 767 49.3 903 767 54.8 903 767 21.6 903 768 19.0 903 768 20.4 903 768

Plum (without pits) <-20 20.3 911 769 28.8 911 769 29.2 911 769 48.4 911 770 38.6 911 770 38.9 911 770

Dried Plum (without pits) <-20 17.6 841 729 16.0 841 729 16.4 841 729 22.0 841 730 32.0 841 730 21.7 841 730Diflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399504 Page 11 of 12 `TABLE C.3. Residue Data from Crop Field Trials with Diflubenzuron.

Trial ID (City, State/Year) Zone Crop/ Variety Matrix Total Rate (lb ai/A) PHI (days) Diflubenzuron (ppm) CPU (ppm) PCA (ppm) Combined Residues 1

(ppm) AR05 (Clarksville, AR/ 2009) 4 Peach/ Crest Haven Fruit without pit 0.494 16 0.10, 0.09 <0.005 <0.005 0.11, 0.10

CA39 (Parlier, CA/2009) 10 Peach/ June Flame Fruit without pit 0.503 14 0.12, 0.09 <0.005 <0.005 0.13, 0.10

CA41 (Parlier, CA/2009) 10 Peach/ June Flame Fruit without pit 0.508 0 0.16, 0.29 <0.005 <0.005 0.17, 0.30 7 0.15, 0.12 <0.005 <0.005 0.16, 0.13 14 0.08, 0.08 <0.005 <0.005 0.09, 0.09 21 0.08, <0.05 <0.005 <0.005 0.09, 0.06 MI17 (Fennville, MI/2009) 5 Peach/ Redskin Fruit without pit 0.502 14 0.40, 0.47 <0.005 <0.005 0.41, 0.48

NC07 (Jackson Springs/2009) 2 Peach/ Contender Fruit without pit 0.504 16 0.13, 0.14 <0.005 <0.005 0.14, 0.15

NJ04 (Cream Ridge, NJ/2009) 2 Peach/ Loring Fruit without pit 0.510 15 0.09, 0.17 <0.005 <0.005 0.10, 0.18

NJ05 (Cream Ridge, NJ/2009) 2 Peach/ Suncrest Fruit without pit 0.499 14 0.26, 0.26 <0.005 <0.005 0.27, 0.27

CA38 (Gridley, CA/2009) 10 Plum/ French Fruit without pit 0.484 13 0.06, 0.09 <0.005 <0.005 0.070, 0.10

CA40 (Parlier, CA/2009) 10 Plum/ John W Fruit without pit 0.502 14 <0.05, <0.05 <0.005 <0.005 0.060, 0.060

CA42 (Parlier, CA/2009) 10 Plum/Black Splendor Fruit without pit 0.505 14 <0.05, <0.05 <0.005 <0.005 0.060, 0.060

CA43 (Gridley, CA/2009) 10 Plum/ French Fruit without pit 0.484 13 0.11, 0.10 <0.005 <0.005 0.12, 0.11

Dried Fruit without pit 0.19 <0.005 <0.005 0.20

WA18 (Wapato, WA/ 2009) 11 Plum/ Late Fruit without pit 0.499 10 0.05, 0.06 <0.005 <0.005 0.060, 0.070

1 Diflubenzuron, CPU and CPA residues were determined by Smith ers Viscient Laboratory. For residues <0.05 and <0.005 ppm, values of 0.05 and 0.005 were used to determined combin ed residues of diflubenzuron + CPU + PCA

TABLE C.4. Summary of Residue Data from Crop Field Trials with Diflubenzuron.

Commodity Total Applic. Rate (lb ai/A) PHI (days) Combined Residues (diflubenzuron, CPU and PCA) (ppm) n Min. Max. HAFT 1 Median Mean Std. Dev.

Peach 0.50 0 2 0.17 0.30 0.24 0.24 0.24 0.090 7 2 0.13 0.16 0.14 0.14 0.14 0.020 14-16 14 0.090 0.48 0.44 0.14 0.19 0.12

21 2 0.060 0.090 0.080 0.080 0.080 0.020 Plum 13-14 10 0.060 0.12 0.12 0.060 0.080 0.020 Dried Plum 13 1 0.20 0.20 NA 2 NA NA NA

1 HAFT = Highest Average Field Trial.
2 NA = Not applicable



### D. CONCLUSION

The magnitude of the residue study of di flubenzuron on peach and plum was conducted consistent with standard agricu ltural practices according to pr oposed experimental designs. The weather conditions at each site were within normal parameters during the growing season, exceptDiflubenzuron/108201/Chemtura Corporation/400 DACO 7.4.1/7.4.2/OPPTS 860.1500/OECD IIA 6.3.1, 6.3.2, 6.3.3 and IIIA 8.3.1, 8.3.2, 8.3.3 Crop Field Trial/ Residue Decline – Peach and Plum

PMRA Submission No. /DP Barcode D423328 /MRID No. 49399504 Page 12 of 12 

### that anomalous weather events were recorded at the NJ04 and NJ05 field sites where temperature and rainfall varied. These occurren ces had no adverse impact on the study.

The LC/MS/MS residue analytical methods used for determining diflubenzuron, CPU, and PCA in/on peach and plum were validated and adequate for data collection. Storage stability data indicated that residues were stable under the cond itions that samples were held between harvest and analysis. Following two foliar applications of Dimilin 2L at 14 days RTI, combined residues of diflubenzuron, CPU and PCA were 0.06-0.48 ppm in peaches harvested at 14-16 days PHI and 0.06-0.12 ppm in plums harvested at 10-14 days PHI. Combined residues of diflubenzuron, CPU and PCA in dried plum were 0.20 ppm. In the decline trial, combined residues on peach declined from 0.24 ppm at 0-day PH I to 0.08 ppm at 21-days PHI.

E. REFERENCES

US EPA DER (14-Sep-2006): MRID 46609501. Corle y, J. (2005) Diflubenzuron: Magnitude of the Residue on Small Grain. Lab Proj ect Number: 08024.02-PTR01. Unpublished study prepared by Interregional Research Project No. 4 (IR-4). 800 p.

F. DOCUMENT TRACKING

RDI: T. Morton (6/20/2015) Petition Number(s): 4E8306 DP Barcode(s): D423328 PC Code: 108201

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