UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, DC 20460

OFFICE OF CHEMICAL SAFETYAND POLLUTION PREVENTION



### PC Code: 108201 

### DP Barcodes: 403093, 403094,403095,403098,403099,and403100 DECISION: 465091, 465086, 465089, 465090, 465092, 465087 

### Date: November, 20, 2012
MEMORANDUM Subject: Ecological Risk and Drinking Water Assessments for Proposed Label Amendments ofDiflubenzuron
To: Autumn Metzger, Risk Manager Reviewer John Hebert, Risk Manager Registration Division (7505P)

From: 

# ,-,_ ' ( f**~** t!/lolt2___ Faruque Khan, Ph.D., Senior Scient4"st-/

## ~**~** '-- · .-

Approved By:

### Ste~hen Wente,

### ~h.D., Biologist

### ~7 

# -:"3 (**>---=?~_** Environmental Risk BranchI**~-** 

### ·· ' Environmental Fate and Effects Division (7507P) 

## l( ) l 1 

## !Cl

# M ICVv.**(()~** .ltl

# J~ J

### Ed_Odenkirchen, Ph.D., Acting_

## Br~ch**(:hi~f ~** }'(c,.

## ~- \\.\

## ~o\ \.Y · 

### Sujatha Sankula, Ph.D. Lead Bwlogist ,\...,_,.:.\'--- 1

### ~---~ Environmental Risk Branch I Environmental Fate and Effects Division (7507P)

The Environmental Fate and Effects Division (EFED) has conducted an ecological risk assessment and a drinking water assessment for human health in response to Chemtura Corporation's request for several amendments in the Micromite 80WG (EPA Reg. No. 400- 487), Diflubenzuron 90% Concentrate (EPA Reg. No. 400-466) and Dimilin® 2L(EPA Reg. No. 40-461) product labels. Label amendments for the above product labels include the following:
• Add the entire citrus crop group (Crop Group 1 0-09), which replaces oranges, grapefruits, tangerines and pommelos
• Reduce retreatment intervals from 90 days to 30 days
• Allow lowvolume (3 to 5 gallonper acre) with spray nozzles thatproduce a droplet size ofa volume median diameter (Dvo.s) of2: 90J.lm
• An additional change in the Dimilin 2L (EPA Reg. No.400-461) label to include grasses/forages grown for biofuel, biomass or bioenergyproduction

### Proposedchanges like reducedretreatmentintervals and low volume application with spray nozzles thatproduce a droplet size ofDvo 5 

### of2: 

### 90J.!m may have implications onexposure assessment and consequently in the risk assessment. Ecological risk as well as drinking water assessment was performed to address label amendments requested by ChemturaCorporation. Potential risks to non-target organisms are summarizedin Table 1. 

### RQs exceededthe acute (RQ?:0.05) and chronic risk LOC (RQ?:l.O) for bothlisted and non-listed freshwater and estuarine/marine invertebrates only (Table 1). 

### Risks were not identified for any othertaxa. Potential risks to listed species based on location analysis due to the expanded use of diflubenzuron oncitrus crop group and grasses/forages grown for biofuel, biomass/bioenergy productionwill be evaluated inthe future RegistrationReviewrisk assessment for diflubenzuron.

Table 1. SummaryofPotentialRisks for theProposed LabelModification of Diflubenzuron Taxonomic Group Use Terrestrial Terrestrial Aquatic Aquatic Birds Mammals Fish Invertebrates Plants Invertebrates & Mollusks Plants Citrus Crop



### -- -- a



### -- -- ,jb



### -- -- •Notoxicity data submitted for terrestrial plant by the registrant. Giventhe mode ofaction ofdiflubenzuron, effects are not anticipated on terrestrial plants. bAcute and chronic LOCs are exceeded for freshwater and estuarine/marine invertebrates


### Diflubenzuron and CPU Residue in DrinkingWater Sources for Human Health


### The estimated drinking water concentrations (EDWCs) for diflubenzuron use oncitrus
are higherthanthe previously recommended annual mean (chronic/non cancer) and 30 year average (chronic/cancer) concentrations for surface water. Therefore, the currently calculated EDWCs (3.47J.lg 

### /L for the peak (acute) concentration, 0.26 

### J.lg /L for the annual mean (chronic/non cancer) concentration, and 0.12 

### J.lg /L for the 30 year average concentration (chronic/cancer) are recommended for diflubenzuron.

The current EDWCs of4-chlorophenyl urea (CPU) for surface water do not supersede the drinking water concentrations previously estimated (US EPA, 2002: D279732) for drinking water. Therefore, the values (20.68 Jlg/L 

### for the peak (acute) concentration, 12.52 flg 

### IL for the annual mean (chronic/non-cancer) concentration, and 8. 81 flg 

### IL for the 36 year average concentration (chronic/cancer) from the previous drinking water assessment are recommended.
Since requested label modifications have no implication in groundwater modeling, groundwater exposure for drinking water was not performed. The previous SCI-GROW model estimated the concentrations ofparent diflubenzuron andthe degradate CPU in drinking water from shallow ground water sources to be 0.006 flg 

### IL and 0.201 flg 

### IL, respectively (US EPA, 2002). The above concentrations canbe considered as boththe acute and chronic value for the respective chemicals.

2

## Table of Contents

1. Scope of Assessment 2. Nature of the ChemicalStressor 3. Exposure 4. AquaticRiskAssessment 5. 

### Toxicity DatafortheParent Compound forAquaticorganisms 6. TerrestrialRiskAssessment 7. 

### Toxicity Datafor theParent Compound for terrestrialorganisms 8. ListedSpecies Concerns 9. Uncertainties &

### Data Gaps 10. Reference 11.AppendixA. SamplePRZMIEXAMSOutput 12.AppendixB. T-REXOutputs

3 

### 3 4 

### 5 

### 10 10 12 12 14 14 

### 15 16 30

### 1. Scope of Assessment

The rationale to evaluatepotential risks to terrestrial and aquatic organisms is to capture the requested modificationin selected diflubenzuronproduct labels. The estimated drinking water concentrations (EDWCs) for diflubenzuron and its major degradate, 4-chlorophenyl
urea (CPU) were also estimated for surface water, source ofdrinking water for humanhealth. Label amendments for the productlabels (Micromite 80WG(EPAReg. No. 400-487), Diflubenzuron 90% Concentrate (EPAReg. No. 400-466) and Dimilin® 2L(EPAReg. No. 40-461) include the following modifications:
• Addthe entire citrus crop group (Crop Group 1 0-09), which replaces oranges, grapefruits, tangerines andpommelos
• Reduce retreatment intervals from 90 days to 30 days
• Allow lowvolume (3 to 5 gallonper acre) with spray nozzles that produce a droplet size ofa volume median diameter (Dv05) 

### of2: 90j..Lm
• An additional change inthe Dimilin 2L (EPA Reg. No.400-461) label to include grasses/forages grown for biofuel, biomass orbioenergyproduction Proposed changes like reducedretreatment intervals and lowvolume application with spray nozzles thatproduce a droplet size ofDvo.s of2: 90j..Lm mayhave implications onexposure assessment and consequently inthe risk assessment. Expanding diflubenzuron use for entire citrus crop group andthe inclusion ofgrasses/forages grown for biofuel, biomass/bioenergy productionwill also cause geographic expansion ofdiflubenzuron uses. Table

### 2 includes the applicationrates ofcurrent diflubenzuronuses oncitrus and grasses/forages. Since there are no changes inapplication methods andrate for grass/forages use (, revised assessment is not warranted for grasses/forages atthis time (U.S. EPA, 2008, D346844) 

### jTablel.C
......

## Aftl

.....: ... feFcljBubeazunm**Ct~~TattLabel** 

### Proposed

## ~ ......Propesed**~** 

## LaW 

# ... bte AnnualRate 

# I Micromite80WG,Diftubenzuron 90% Concentrate, and Dimilin® 2L Oranges, Citrus Grapefruits, Entire Crop Ground: Air 0.3125 lb a.i./acre 0.9375 lb a.i./acre Tangerines and Group Blast Pommelos (10-09) 

# I Dimilin® 2L 

### Added grasses/forag
es grown for Aerial and 

### Grasses/forages biofuel, Ground 0.0313 lb a.i./acre 0.0938 lb a.i./acre 

### biomass or bioenergy production


### 2. Nature of the ChemicalStressor Diflubenzuronis a benzoylphenylureaacaricide/insecticide (insect growth regulator) usedto control molting insectpests in agricultural and nonagricultural settings. The

4

### physicochemical properties**su~gest** 

### that diflubenzuronhas a low solubility inwater (0.8 mg/L). The vaporpressure (9.0 x 

### 10" 1 

### mm Hg) and Henry's LawConstant (1.19 x 10"11

### atm-m3/mol) indicate that diflubenzuron is a non-volatile chemical. The log Kow of3.70 suggests that diflubenzuronhas a potential to bioaccumulate. However, diflubenzuron does appearto accumulate at low levels and depurate rapidly in fish tissue. The reported bioconcentration factors ranged from 34 to 200X for fillet, 78 to 360X for whole fish, and 100 to 500X for viscera.

Based on registrant-submitted data, diflubenzuron appears to be relatively non-persistent and slightly mobile undernormal use conditions. Diflubenzuron is relatively stableto hydrolysis and photolysis. The majorroute ofdissipation appears to be biotic processes (half-life of approximately 

### S 14 days for aerobic soil metabolism). Two major degradates, a maximum of48 %of4-chlorophenylurea (CPU or p-CPU) at day 16 in a aerobic aquatic metabolism study and a maximum of31% of2,6-diflubenzoic acid (DFBA) at day 42 in anaerobic aquatic metabolism study were identified in the submitted environmental fate studies for diflubenzuron. However, there is insufficient data on the major degradates ofdiflubenzuronto adequately assess their persistence and mobility.

Available data indicatethat it is unlikely that diflubenzuron will contaminate ground water or appreciably volatilize and be transportedthrough long-range atmospheric transport processes. However, CPU, one ofthe degradates ofdiflubenzuron has a much greaterpotential to leach through soil. Spray drift andtransport with eroded soil in runoffare thought to be the main mechanisms oftransport from the site ofapplication. Additional informationregarding the environmental fate and transport ofdiflubenzuron can be found in the previous ecological risk assessment to evaluate potential direct and indirect effects on the Californiared-legged frog (Rana aurora draytonii) (CRLF) (U.S. EPA, 2009;**h_!tp://w\~Vv.cpa.gov/espp/litstatus/e!Tects/redlcg-frog/ditlubenzuron/analvsis.pdl).** 

### 3. 

### Exposure

3.1. 

### TerrestrialExposuresandRiskAssessment

The Terrestrial Exposure (T-REX) model (Version 1.5.1), an EFED computer model that uses a first-order dissipationrelationship to account for residue dissipation between applications, was used to estimate exposure concentrations ofdiflubenzuronto terrestrial wildlife. The T-REX simulationmodel incorporates the Kenaga nomogram (Fletcher etal. 1994; Boergerand Kenaga 1972; Pfleeger et al. 1996) (relationship between the amount ofpesticide applied and the amount ofpesticideresidue present on a given food item). The model also calculates the peak concentration ofpesticideresidues on each food item ona daily interval for one yearusing a first order decay function based on the concentrations present from both the initial and additional applications. In additionto exposure concentrations (dose and diet-based), the I-REXmodel calculates risk quotients based on food items for mammals and birds, including herbivores, insectivores, and granivores. For dose-based exposures, three weight classes ofmammals (15, 35, and 1000 g) and birds (20, 100, and 1000 g) are considered.

5

### A default foliar dissipationhalf-life of35 days was used inthis assessment. Example input parameters, suchas applicationrate, interval, andnumber ofapplications, used inthe T-REX model are presentedwith corresponding EECs in (Appendix B).


### 3.2. AquaticExposureAssessment

Estimated environmental concentrations (EECs) for aquatic exposures and estimated drinking water concentrations (EDWCs) for humanhealthwere calculated for the proposed changes oflowvolume application and retreatment intervals for diflubenzuron labels using the Tier II PRZM/EXAMS model withthe standard pond and drinking waterreservoir scenarios. Model description canbe obtained from http://www.epa.gov/oppefed 1/modcls/watcr/#przm. Air-blastmodule ofAgDRIFT (version 2.1.1) model was used in estimating spray drift fraction. Table 3liststhe inputparameters used in the PRZMIEXAMS modeling for diflubenzuron. Inputs and outputs ofPRZM/EXAMS and AgDRIFT modeling canbe found in Appendix A. Table 4 provides surface water EECs for aquatic exposure.

Maximum application 0.3125 Ditlubenzuron 90% Rate lb a.i./A Dimilin® 2L Micromite 80WG NumberofApplications 3 Ditlubenzuron 90% Dimilin® 2L
Minimum Application Micromite 80WG NA Ditlubenzuron 90% Intervals (days) Dimilin® 2L FL Citrus STD" Based on Active growing periods ofcitrus Application Date Multiple dates PRZM/EXAMS March 01, 15, 30, 15 30 Scenario
Micromite 80WG For foliar application according to Depth ofIncorporation 0 Ditlubenzuron 90% Input parameter guidance (USEPA, (inches) Dimilin® 2L 2009) Micromite 80WG Method ofApplication Ground air-blast spray Ditlubenzuron 90% Dimilin®2L
Ground: 0.99 Input parameter Default values for ground spray Application Efficiency guidance (USEPA, 2009) Spray Drift Fraction AgDRIFT Based on Air-blast with 25 ft buffer Air-blast: 0.0Ib modeling Estimated spray drift fractions are same for both pond and reservoir
Molecular Mass (g/mol) 311 MRID 485969-0I Product chemistry data

VaporPressure (Torr) 9.0 X 10- 10 MRID 485969-0I Product chemistry data Henry's Law Constant 1.19 X 10- 11 Estimated EPISUITE 4.1 (atm m3/mol)



### 6

### Table3. PRZMIEXAMS InputPanuaetersf8r,D8dw··-,,.._... • ·- ·".· !J;' .. 

# ,, cOIIHaeRcs ·····:. 

### Parameter Value**~** Solubility in Water 0,08 MRID 485969-01 Product chemistry data (mg/L) Hydrolysis tl/2 at pH 7.0 119 MRID 014355 

### -- (days) Aquatic Photolysis t112 80 MRID 40816301



### -- (days) MRID 41087802
MRID 41722801 90th percentile upper confidence Aerobic Soil 4.7 MRID 46888703 bound on the mean half-life of Metabolism t 12 (days) MRID 46888708 diflubenzuron

Aerobic Aquatic 901hpercentile upper confidence 25.2 MRID 41837601 bound on the mean half-life oftotal Metabolism t12 (days) toxic residue ofimazosulfuron

Anaerobic Aquatic 102 (34 X 3)" MRID 41837601 Input parameter guidance (USEPA, Metabolism t112 (days) 2009)
Soil Partitioning MRID 00157842 Represent average Kroc from 4 soils 3961 Coefficient (Koc; mllgoc) MRID 46895401

• Since low volume application is restricted in California, FL Citrus STD is the only scenario available for PRZM/EXAMS modeling for Citrus crop group.

b =Spray drift fraction was estimated using AgDRlFT 2.1.1 model- Tier I Air-blast scenario (citrus, aerosol to fine droplet) and the Guidance on Development and Use ofthe Index Reservoir in Drinking Water Exposure Assessments. lillJL: www.eQa.gov. OQQefed Ihnodels/waterlindex reservoir dwa.html#memo

cDue to reported half-life for a single anaerobic aquatic metabolism study, the input half-life was multiplied by 3 according to Guidance for Selecting Input Parameters in Modeling for Environmental Fate and Transport of Pesticides. Version 2.1 October22, 2009.

FL Citrus STD (PRZM/EXAMS) (3 app. X 0.3125 lbs ai/A) Water



### 3.2.1 Drinking WaterExposure forhumanHealth 0.91-1.55 0.50-0.76 0.30-0.45



### Table 5 provides EDWCs ofdiflubenzuron residue in surface water source for drinking water. Standardpercent cropped areas (PCA) were used for proposed uses as estimates ofthe extent ofwatershed on which crops are grown. The default PCA of 1.0 was used for the proposed uses because diflubenzuron canbe used inboth agricultural and non-agricultural settings (USEPA 2012). These EDWCs for surface water are higherthanthe previously reported for citrus with 0.21 ).lg /L for the 1in 10 year annual mean (chronic) concentration, and 0.09 ).lg

7

### /L for the 3 6 year average concentration except 3.47j.tg /L for the 1 in 10 year annual peak (acute) concentration (USEPA 2002, DP 279732+). Therefore, the currently calculatedEDWCs of 3.4**7~-tg** 

### /L for the 1in 1 0 yearannual peak (acute) concentration, 0.26 j.tg /L for the 1in 1 0 year annual mean (chronic) concentration, and 0.12 j.tg /L for the 30 year average concentration
are recommended. Estimated drinking water concentrations were also calculated for the major degradate, 4- chlorophenyl urea (CPU) ofdiflubenzuron using PRZM/EXAMS model. 

### Table 5 provides input values used inCPU modeling. 

### Table 6 provides the EDWCs ofCPU residue in surface water. Sample PRZMIEXAMS output canbe found in

### Appendix A. The EDWCs ofCPU in drinking water for citrus uses are lowerthantheprevious reported values for drinking water assessment (US EPA 2002, DP 279732+). Thereportedvalues were 20.68 j.tg/L for the 1 in 10 year annual peak (acute) concentration, 12.52 j.tg /L for the 1in 10 year annual mean (chronic/non-cancer) concentration, and 8.**81~-tg** 

### /L for the 36 year average concentration (chronic/cancer). Therefore, the currentEDWCs (Table 5) for surface water do not supersede the drinking water concentrationspreviously estimated for CPU.



### Table5. PRZMIEXAMSInputParametersfor CPUModelin2 Parameter Value Source Comments Micromite



### -- Maximum 80WG application Rate lb 0.0.64 1 

### Diflubenzuron a.i./A 90% Dimilin® 2L Micromite 80WG Based on parent application Number ofApplications 3 Diflubenzuron 90% Dimilin® 2L
Minimum Application Micromite 80WG Based on parent application NA Diflubenzuron 90% Intervals (days) Dimilin® 2L FL Citrus Basedon During active growth ofcitrus Multiple dates : PRZM/EXAMS Application Date March 01, 15,30 Scenarios Aprill5, 30 May 15, 30 June 15, 30 Micromite 80WG For foliar application according to Depth ofIncorporation Diflubenzuron 90% (inches) 0 Dimilin® 2L Input parameter guidance (USEPA, 2009)
Method ofApplication Ground application Assumed Contribution from degradation Application Efficiency Ground: 1.0 Assumed Contribution from degradation

Spray Drift Fraction 0 Assumed Contribution from degradation
Molecular Mass (g/mol) 100.6 DP D279732+ Values from previous assessment US EPA, 2002 Vapor Pressure (Torr) 1.65 X 10-04 DP D279732+ Values from previous assessment US EPA, 2002



### 8

### Table5. PRZMIEXAMS InputParameters for CPUModeling Parameter Value Source Comments Henry's Law Constant OP 0279732+ Values from previous assessment 1.49 x 

## ro-'o US EPA, 2002 (atm m3/mol) Solubility in Water OP 0279732+ Values from previous assessment (mg/L) 1770 US EPA, 2002 Hydrolysis tl/2 at pH 7.0 0 Assumed No data (days) Aquatic Photolysis t112 0 Assumed No data (days)
Aerobic Soil OP 0279732+ Values from previous assessment Metabolism t112 (days) 11 I US EPA, 2002

Aerobic Aquatic OP 0279732+ Twice the aerobic metabolism t112 Metabolism t112 (days) 222 US EPA,2002 was used

Anaerobic Aquatic 0 Assumed No data Metabolism t,;2 (days)
Soil Partitioning DP 0279732+ Values from previous assessment Coefficient (Koc; m1/g0c) 246 US EPA, 2002



### Table**6~** 

### Raage of

### Estilmltfed-·!!j·f! forSudaeeWater

Surface:Water (model)



### Diflubenzuron
FL Citrus STO Water 1.92-3.46 0.18-0.26 0.09-0.12 (3 app. X 0.3125 lbs ai/A)**(PRZM/EXAMS)r-------------~--------~--------~----------~------~**

FL Citrus STO (3 app. X 0.064 1bs ai/A) 1 

### 4-chlorophenyl urea (CPU)

Water 2.11-2.69 0.80-0.87 0.60-0.64 

## '= Diflubenzuron application rate (0.3125 lb/A) x [(0.37, the maximum conversion rate from the aerobic soil degradation ofdiflubenzuron to CPU in laboratory studies) x (0.55, the molecular weightratio of CPU to diflubenzuron)]



### Since requested label modifications have no implication in groundwater modeling, groundwater exposure for drinking water was not performed. The previous SCI-GROWmodel estimates the concentrations ofparent diflubenzuron andthe degradate CPU in drinking water from shallow ground water sources to be 0.006 f.lg /L and 0.201 f.lg /L, respectively (DP) (YS EPA, 200???).

9

### The above concentrations should be considered as boththe acute and chronic value for the respective chemicals.


### 4. Dijlubenzuron ToxicityData forAquaticorganisms

A summary ofthe aquatic toxicity data for diflubenzuron from registrant-submitted studies is provided in 

### Table 7.

Table

### 7. Summary oftheEndpointsfrom Submitted Aquatic Toxicity Studies for Difl.ubenzuron Study Type Species Toxicity Value MRID & Status Acute

- Freshwater Rainbow trout 00056150 Fish (Oncorhynchus mykiss) 96-hr LC50: 136000 J..lg/L Acceptable 850.1075 Acute

- Freshwater Bluegill sunfish (Lepomis 00056150 Fish 96-hr LC50: 129000J..Lg/L 850.1075 macrochirus) AcceptableAcuteEstuarine/Marine Sheepshead minnow 96-hr LC50: >13.0J..Lg/L 42940101 Fish (Cyprinodon variegatus) Acceptable 850.1075 Chronic

- Freshwater Fathead minnow NOAEC: 100.1 J..lg/L 00099755 Fish 850.1400 (Pimephalespromelas) LOAEC: >100.1 J..Lg/L Acceptable Acute

- Freshwater Water flea (Daphnia 45252204 Invertebrate 48-hr EC50: 2.6 J..Lg/L

850.1010 magna) SupplementalAcuteEstuarine/Marine Quahog clam (Mercenaria 96-hr LC50: >320 J..Lg/L 41392002 Invertebrate mercenaria) Acceptable

850.1025AcuteEstuarine/Marine Grass shrimp 96-hr LC50: 0.64 J..lg/L 00038612 Invertebrate (Palaemonetespugio) Acceptable

850.1035 Chronic

- Freshwater Water flea (Daphnia NOAEC: 0.05 J..Lg/L 00010856 Invertebrate

850.1300 magna) LOAEC: 0.075 J..Lg/L SupplementalChronicEstuarine/Marine Mysid shrimp NOAEC 0.045 J..lg/L 40197001 invertebrate (Americamysis bahia) LOAEC 0.086 J..Lg/L Acceptable

850.1300 Aquatic- Non- Green algae 96-hr EC50: 200 J..l/L 42487101 vascular Plants (Pseudokirchneriella NOAEC: 200 J..Lg/L Supplemental 850.5400 subcapitata (no effects noted) Aquatic

- Vascular 7-day EC50: 190 J..lg/L 42940103 Plants Duckweed (Lemna gibba) NOAEC: 190 J..lg/L Acceptable 850.4400 (no effects noted)



### 10

### 5. 

### AquaticRiskAssessment
5.1. Fish

Potential risks to freshwater fish from the proposed label modification were evaluated using the acute toxicity data for a Bluegill sunfish (Lepomis macrochirus) and chronic toxicity data for Fathead minnow (Pimephalespromelas). RQs are summarizedin

### Table 8. None ofthe acute and chronic RQs exceeded the listed ornonlisted species LOC for requested label changes. Therefore, potential risks to freshwater fish are unlikely.

A definitive LC50 

### andNOAEC were not established for diflubenzuron estuarine/marine fish. No chronic toxicity for estuarine/marine fish was submitted by the registrant. As a result, acute and chronic risk quotients were not calculated for estuarine/marine fish. Submitted freshwater fish data showed no effects. Given the mode ofaction, effects are not anticipated on estuarine/marine fish 

### Table8. Acute and ChronicRiskQuotientsforFreshwaterFish fortheProposedLabel Modifications ofDitlubenzuron
PRZM/EXAMS Peak Acute Freshwater 60-day Chronic Use Scenario EEC Freshwater (Application Date) (JJ.g/L) FishRQ1 EEC Fish RQ2 (JJ.g/L) Citrus FL Citrus 0.91-1.55 <0.05 0.30-0.45 <1.0 (Croup Group 10-09) (Multiple Dates)
1 Bluegill sunfish (Lepomis macrochirus) = 129,000 ppb. 2 Fathead minnow (Pimephalespromelas) = 100 ppb.



### 5.2. AquaticInvertebrates

Potential risks to freshwater invertebrate from the proposed label modification were evaluated using the acute and chronic toxicity data for a Water flea (Daphnia magna). RQs are summarized in 

### Table 9. Both ofthe acute and chronic RQs exceededthe LOC for requested label changes. Therefore, potential risks to freshwater invertebrates are likely.



### Table9. Acute and ChronicRiskQuotients for FreshwaterInvertebratesforthefor the Proposed LabelModifications ofDitlubenzuron
PRZM/EXAMS Peak Acute Freshwater 21-day Chronic Use Scenario EEC Invertebrate EEC Freshwater (Application Date) (JJ.g/L) RQt (Jlg/L) Invertebrate RQ2 Citrus FL Citrus (Croup Group I0-09) (Multiple Dates) 0.91-1.55 0.4-0.6* 0.50-0.76 10.0- 15.2**

1Water flea (Daphnia magna)= 2.6 11g/L. 2 Water flea (Daphnia magna)= 0.05 11g/L. *Exceeds LOC (0.05). **Exceeds LOC (1.0).



### 11

### Potential risks to estuarine/marine invertebrate from the proposed label modification were evaluatedusing the acute toxicity data for a Grass shrimp 

### (Palaemonetespugio) and a chronic toxicity datafor a Mysid shrimp 

### (Americamysis bahia). RQs are summarized in 

### Table 10. Both ofthe acute and chronic RQs exceededthe listed and nonlisted species LOC for requested label changes. Therefore, potential risks to estuarine/marine invertebrates are likely.



### Table 10. Acute andChronicRiskQuotientsforEstuarine/MarineInvertebratesfor the fortheProposedLabelModifications ofDiflubenzuron

PRZMIEXAMS Peak Acute Freshwater 21-day Chronic Use Scenario EEC Invertebrate EEC Freshwater (Application Date) (!lg/L) RQt (!lg!L) Invertebrate RQ2
Citrus FL Citrus 0.91-1.55 0.70-2.42* 0.50-0.76 11.1-16.9** (Croup Group 10-09) (Multiple Dates)
1 Grass shrimp (Palaemonetespugio) = 0.64 j.!g/L. 2 Mysid shrimp (Americamysis bahia) = 0.045 j.!g/L. *Exceeds LOC (0.05). **Exceeds LOC (1.0). 

### Insert here the sectiOn onnskto terrestnal organisms from before


### 5.3. AquaticPlants

Potential risks to aquatic plants from the proposed label modificationwere evaluated usingthe toxicity data for a vascularplant 

### (Lemna minor) and a non-vascular plant 

### (Pseudokirchneriella subcapitata). RQs are summarizedin

### Table 11. None ofthe non-listed vascular and non-vascularplant RQs exceeded the LOC for requested label changes. Therefore, potential risks to non-listed vascular and non-vascular aquatic plants are unlikely.



### Table 11.RiskQuotientsforAquaticPlantsfortheProposedLabelModifications of Diflubenzuron PRZMIEXAMS Peak Non-listed Non-listed Non-vascular Use Scenario EEC VascularPlant PlantRQ2 (ApplicationDate) (!lg/L) RQt Citrus FL Citrus 0.91-1.55 < 1 <I (Croup Group 1 0-09) (Multiple Dates)

1 DuckweedEC50 = 190 j.!g/L. 2 Green algae EC50 = 200 j.!g/L.



### 6. TerrestrialRiskAssessment
Effects to TerrestrialOrganisms

Table 12summarizesthe terrestrial toxicity data fordiflubenzuronbased on an evaluation of submitted studies.

12

### Table 12. Summary ofthe Endpoints from Submitted Terrestrial Toxicity Studies for Diflubenzuron Study Type Species Toxicity Value MRID & Status Acute

- Avian Oral Red-winged balckbird LD50: 3763mg!kg-bw/day 00060384 850.2100 (Agelaiusphoeniceus) Acceptable Acute -A vian Bobwhite Quail (Colinus 00039080 Dietary LC50: >4640 mg!kg-diet 850.2200 virginianus) Acceptable Acute

- Avian Mallard Duck 00038613 Dietary (Anasplatyrhynchos) LC50: >4640 mg!kg-diet Acceptable 850.2200 Chronic -Avian Bobwhite Quail (Colinus NOAEC: 500 mg/kg-diet 41668002

Reproduction

850.2300 virginianus) LOAEC: I000 mg/kg-diet Acceptable Chronic -Avian Mallard Duck NOAEC: 500 mg!kg-diet 4168001

Reproduction

850.2300 (Anasplatyrhynchos) LOAEC: 1000 mg!kg-diet Acceptable Acute- Mammalian Oral Rat (Rattus norvegicus) LD50: >5000 mg/kg-bw 00157103 Acceptable 870.1100 Chronic- NOAEL: 250mg/kg-bw/day Mammalian Rat (Rattus norvegicus) LOAEL:2500 mg!kg-bw/day 43578301 Acceptable Reproduction (development effects decreased

870.3800 pup weight) Acute

- Contact Honey Bee 00099890 Toxicity NOAEL>114.8 f.!g/bee 850.3020 (Apis mellifera) Acceptable
Acute oral and acute Honey Bee LD50: >30 f.lg/bee 05001991 contact (Apis mellifera) Acceptable Pollinator Field Honey Bee 00071816 Study NOAEL>5 lbs ai/acre 850.3040 (Apis mellifera) acceptable



### 6.1. Birds andmammals.

No acute LOC exceedances for birds based onLD5

### o: 3763mg/kg-bw/daywas observed (Appendix B). Since the LC50 

### for birds was non-definitive values of>4640 mg/kg-diet, andno treatment related mortality was observed,risk quotients were not calculated. Based on application rates and the results ofthe acute toxicity studies, acute riskconcern levels would not be exceeded for birds.

The LD50 

### for mammals was a non-definitive value of>5000 mg/kg bw and no treatment related mortality was observed. Therefore, acute risk quotients were not calculated andthere is
no concern ofacute risk to mammals atthis time.

No chronic LOC exceedances for birds and mammals (Appendix B).

6.2. 

### Terrestrialplants.

No toxicityterrestrial plant studies were submittedby the registrant. Therefore, no terrestrial EECs for terrestrial plant exposure were calculated for the proposed modification of

13

### diflubenzuron labels. Submitted aquatic plant data showed no effects. Giventhe mode ofaction, effects are not anticipated onterrestrial plants.


### 6.3. TerrestrialInvertebrates.

EFED currently does not estimate riskquotients for terrestrial non-target insects. Based
onthe acute contacttoxicity study to honeybees, the LD5

### ois 114.8 1-1g/bee. Thus, the toxicity category for the TGAI ofdiflubenzuron inreference to honeybees being exposed is practically non-toxic. Conversely, the 25 WP formulation ofdiflubenzuron is categorized as "Very Highly Toxic" tojuvenile non-targetedterrestrial insects on an acute contactbasis. The LD5

### ovalue was estimatedto be 2 1-1g/bee.


### 7. 

### ListedSpecies Concerns
Expanding diflubenzuronuse for entire citrus crop group andthe inclusion of grasses/forages grown for biofuel, biomass/bioenergyproductionwill cause geographic expansion ofdiflubenzuronuses. Listed species location analysis and potential risks to listed species that couldbe affected directly orindirectly by the extended use ofdiflubenzuron on citrus crop group and grasses/forages grown for biofuel, biomass/bioenergy production will be evaluated in the future RegistrationReviewrisk assessment for diflubenzuron.


### 8. Uncertainties & 

### Data Gaps

Uncertainties and data gaps remainthe same as those described in the previous assessment of diflubenzuron (U.S. EPA, 2009).

14

### References

U.S. EPA 2002. Environmental Fate and Ecological Effects Assessment and Characterizationfor
a Section 3 for Aerial and Ground Spray Treatmentto Pears, Stone Fruits, Almonds, Peppers, and Pasture Grass (DP Barcode D279732, D279735, D278770) Ecological Fate and Effects Division, Office ofPesticide Programs, U.S. Environmental Protection Agency, Washington D.C. May 2002.

U.S. EPA 2006. Environmental Fate and Ecological Risk Assessment for the Registration of Diflubenzuron (Dimilin-2L) Use on Peanuts, Okra, Small Grains-(Winter wheat, Spring wheat, Durum, Barley, and Oats), Pummelo, Mustard Greens, Broccoli, Raab, Cabbage, Chinese (bok choy); Collards; Kale; Mizuna; Mustard spinach; Rape, Greens and Turnip greens. (DP 321153, DP 321278). Ecological Fate and Effects Division, Office of Pesticide Programs, U.S. Environmental Protection Agency, Washington D.C., September 2006.

US EPA, 2008. Section 3 NewUse Request Registration for the use ofDiflubenzuron (Dimilin 2LTM) on turfgrass (for use in sod-farms only). (DP Barcode D346844) U. S. Environmental Protection Agency. Washington, D.C

US EPA, 2009. Guidance for Selecting InputParameters in Modeling the Environmental Fate and Transport ofPesticides, Version II. U.S. Environmental Protection Agency. Washington, D.C. http://www.epa.gov/oppefedl/models/water/

US EPA, 2009. Risks ofDiflubenzuronUse to Federally Threatened California Red-legged Frog (Rana aurora draytonii). U.S. Environmental Protection Agency. Washington, D.C. http://www.epa.gov/espp/litstatus/effects/redleg-frog/ditlubenzuron/analysis.pdf

US EPA. 2012. Development and Use ofPercent Cropped Area and Percent TurfArea Adjustment Factors in Drinking WaterExposure Assessments: 2012 Update http://v,vvw.cpa.gov/oppefcd 1 

### /models/water/pea adjustment dwa.html

15

### Appendix A. Sample PRZM/EXAMS Output
Dijlubenzuron GroundApplication to FL CitrusforAquaticExposure
Table A-1. PRZM/EXAMS EECs (f.lg/L) 

### Output for Multiple Dates

DATE peak 96hr 21day 60day 90day yrly overallavg 01-03 1.55 1.29 0.76 0.39 0.30 0.11 0.06 15-03 1.08 0.91 0.50 0.30 0.26 0.10 0.07 30-03 1.40 1.17 0.69 0.42 0.32 0.11 0.07 15-04 1.10 0.92 0.51 0.37 0.30 0.11 0.07 30-04 1.24 1.03 0.62 0.45 0.38 0.14 0.07 15-05 1.15 0.98 0.55 0.34 0.28 0.10 0.07 30-05 0.92 0.76 0.52 0.36 0.35 0.13 0.07 15-06 1.29 1.07 0.65 0.35 0.28 0.11 0.07 30-06 0.91 0.75 0.47 0.33 0.28 0.10 0.07 

### Dijlubenzuron GroundApplication to FL Citrus forDrinking Water
Table A-2. PRZM/EXAMS EDWCs (f.lg/L) 

### Output for Multiple Dates

DATE peak 96hr 21day 60day 90day yr1y overallavg 01-03 3.46 2.96 1.82 0.89 0.64 0.19 0.09 15-03 2.33 2.00 1.20 0.66 0.55 0.19 0.10 30-03 3.12 2.67 1.68 0.93 0.68 0.20 0.11 15-04 2.29 1.98 1.14 0.82 0.62 0.19 0.12 30-04 2.75 2.35 1.52 0.98 0.83 0.26 0.12 15-05 2.46 2.13 1.26 0.74 0.57 0.18 0.11 30-05 1.95 1.65 1.17 0.78 0.73 0.23 0.10 15-06 2.91 2.48 1.50 0.77 0.60 0.20 0.11 30-06 1.92 1.62 1.10 0.71 0.58 0.18 0.10


### CPU from GroundApplication of Dijlubenzuron to FL Citrus forDrinking Water

Table A-1. PRZM/EXAMS CPU EDWCs (f.lg/L) 

### Outputfor Multiple Dates

DATE peak 96hr 21day 60day 90day yrly overallavg 01-03 2.34 2.15 1.83 1.54 1.31 0.81 0.60 15-03 2.30 2.11 1.65 1.38 1.26 0.85 0.62 30-03 2.34 2.19 1.70 1.46 1.35 0.87 0.63 15-04 2.38 2.22 1.89 1.40 1.26 0.87 0.64 30-04 2.15 2.00 1.72 1.42 1.33 0.86 0.63 15-05 2.11 1.99 1.61 1.29 1.18 0.88 0.62 30-05 2.20 2.03 1.74 1.37 1.26 0.84 0.61



### 1615-06 2.39 2.21 1.89 1.39 1.28 0.82 0.61 30-06 2.69 2.49 1.97 1.47 1.32 0.80 0.60 

### Example of PRZMOutput forAquaticExposure

stored as FLCitrus_01-03.out Chemical: Diflubenzuron PRZM environment: FLcitrusSTD.txt, Modified: Tueday, 29 May 2007 at 12:45:56 EXAMS environment: pond298.exv, modified Tueday, 26 August 2008 at05:14:08 Metfile: w12844.dvf modified Tueday, 26 August 2008 at05:14:22 Watersegment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly 1961 0.42 0.35 0.21 0.15 0.12 0.04 1962 0.41 0.35 0.23 0.19 0.15 0.06 1963 1.62 1.38 0.77 0.40 0.30 0.11 1964 0.30 0.25 0.20 0.17 0.14 0.06 1965 0.21 0.17 0.10 0.08 0.08 0.03 1966 0.23 0.19 0.13 0.11 0.10 0.04 1967 0.27 0.23 0.13 0.10 0.10 0.04 1968 0.21 0.18 0.16 0.12 0.11 0.05 1969 0.69 0.60 0.36 0.20 0.18 0.07 1970 0.74 0.62 0.40 0.26 0.24 0.09 1971 0.36 0.30 0.20 0.14 0.12 0.05 1972 1.68 1.40 0.81 0.44 0.36 0.12 1973 0.32 0.27 0.18 0.12 0.11 0.04 1974 0.24 0.21 0.15 0.12 0.11 0.04 1975 0.21 0.17 0.10 0.08 0.08 0.03 1976 0.23 0.21 0.16 0.12 0.11 0.04 1977 1.57 1.30 0.79 0.42 0.32 0.11 1978 0.28 0.24 0.16 0.11 0.11 0.04 1979 1.42 1.18 0.72 0.38 0.29 0.10 1980 0.58 0.49 0.27 0.18 0.17 0.06 1981 0.21 0.18 0.12 0.10 0.10 0.04 1982 0.59 0.50 0.40 0.26 0.25 0.09 1983 0.23 0.20 0.13 0.10 0.10 0.04 1984 0.53 0.45 0.30 0.23 0.22 0.08 1985 0.43 0.36 0.26 0.21 0.17 0.06 1986 0.23 0.19 0.12 0.10 0.10 0.04 1987 0.39 0.35 0.26 0.20 0.19 0.07 1988 1.37 1.14 0.63 0.33 0.25 0.10 1989 0.34 0.30 0.21 0.15 0.12 0.05 1990 0.21 0.18 0.11 0.09 0.09 0.04



### 17Sorted results Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly 0.03 1.68 1.40 0.81 0.44 0.36 0.12 0.06 1.62 1.38 0.79 0.42 0.32 0.11 0.10 1.57 1.30 0.77 0.40 0.30 0.11 0.13 1.42 1.18 0.72 0.38 0.29 0.10 0.16 1.37 1.14 0.63 0.33 0.25 0.10 0.19 0.74 0.62 0.40 0.26 0.25 0.09 0.23 0.69 0.60 0.40 0.26 0.24 0.09 0.26 0.59 0.50 0.36 0.23 0.22 0.08 0.29 0.58 0.49 0.30 0.21 0.19 0.07 0.32 0.53 0.45 0.27 0.20 0.18 0.07 0.35 0.43 0.36 0.26 0.20 0.17 0.06 0.39 0.42 0.35 0.26 0.19 0.17 0.06 0.42 0.41 0.35 0.23 0.18 0.15 0.06 0.45 0.39 0.35 0.21 0.17 0.14 0.06 0.48 0.36 0.30 0.21 0.15 0.12 0.05 0.52 0.34 0.30 0.20 0.15 0.12 0.05 0.55 0.32 0.27 0.20 0.14 0.12 0.05 0.58 0.30 0.25 0.18 0.12 0.11 0.04 0.61 0.28 0.24 0.16 0.12 0.11 0.04 0.65 0.27 0.23 0.16 0.12 0.11 0.04 0.68 0.24 0.21 0.16 0.12 0.11 0.04 0.71 0.23 0.21 0.15 0.11 0.11 0.04 0.74 0.23 0.20 0.13 0.11 0.10 0.04 0.77 0.23 0.19 0.13 0.10 0.10 0.04 0.81 0.23 0.19 0.13 0.10 0.10 0.04 0.84 0.21 0.18 0.12 0.10 0.10 0.04 0.87 0.21 0.18 0.12 0.10 0.10 0.04 0.90 0.21 0.18 0.11 0.09 0.09 0.04 0.94 0.21 0.17 0.10 0.08 0.08 0.03 0.97 0.21 0.17 0.10 0.08 0.08 0.03

0.10 1.55 1.29 0.76 0.39 0.30 0.11 Average 0.06 ofyearly averages

Inputs generated by pe5.pl- Novemeber 2006

Data used for this run: Output File: FLCitrus_01-03



### 18Metfile: w12844.dvf PRZM FlcitrusSTD.txt scenario: EXAMS pond298.exv environ ment file: Chemica Diflubenzuron I Name: Descripti Variable Value Units Comments
on Name Molecul mwt 311 g/mol ar weight Henry's henry 1.87E-09 atm-mA3/mol Law Const. Vapor vapr 9.00E-10 torr Pressure Solubilit sol 0.08 mg/L y Kd Kd mg/L Koc Koc 3961 mg/L Photolys kdp 80 days Half-life is halflife Aerobic kbacw 25.2 days Halfife Aquatic Metaboli
sm Anaerob kbacs 102 days Halfife ic Aquatic Metaboli
sm Aerobic asm 5.11 days Halfife Soil Metaboli
sm Hydrolys pH 7 119 days Half-life is: Method: CAM 2 integer See PRZM manual lncorpor DEPI em ation Depth: Applicati TAPP 0.35 kg/ha on Rate:



### 19Applicati APPEFF 0.99 fraction
on Efficienc y: Spray DRFT 0.01 fraction ofapplication rate applied to pond Drift Applicati Date 3-Jan dd/mm or dd/mmm ordd-mm or dd-mmm
on Date Interval interval 30 days Set to 0 or delete line for single app. 1 app. rate apprate kg/ha 1 Interval interval 30 days Set to 0 or delete line for single app. 2 app. rate apprate kg/ha 2 Record FILTRA 17: IPSCND 1 UPTKF Record PLVKRT 18: PLDKRT FEXTRC 0.5 Flag for IR EPA Index Pond Res. Run Flag for RUNOFF none none, monthly ortotal(average ofentire run) runoff calc.



### 20

### Exampleof PRZMOutput forDrinking WaterExposure (Dijlubenzuron)

stored as FLCitrus_DW_01-03.out Chemical: Diflubenzuron PRZM environment: FLcitrusSTD.txt,modified Tueday, 29 May 2007 at 12:45:56 EXAMS environment: ir298.exv,modified Tueday, 26 August 2008 at05:14:08 Metfile: w12844.dvf, modified Tueday, 26 August 2008 at05:14:22 Watersegmentconcentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly 1961 0.74 0.64 0.38 0.24 0.19 0.06 1962 0.75 0.65 0.42 0.34 0.27 0.08 1963 3.57 3.14 1.84 0.89 0.64 0.19 1964 0.55 0.48 0.37 0.29 0.23 0.08 1965 0.19 0.17 0.13 0.09 0.08 0.03 1966 0.27 0.24 0.17 0.15 0.13 0.05 1967 0.36 0.31 0.24 0.14 0.14 0.05 1968 0.39 0.37 0.29 0.21 0.16 0.06 1969 1.40 1.23 0.77 0.39 0.33 0.11 1970 1.63 1.41 0.97 0.54 0.47 0.16 1971 0.74 0.64 0.38 0.22 0.17 0.06 1972 3.69 3.16 1.93 1.00 0.78 0.24 1973 0.59 0.50 0.30 0.17 0.15 0.05 1974 0.50 0.43 0.28 0.18 0.14 0.05 1975 0.15 0.13 0.08 0.07 0.06 0.02 1976 0.35 0.31 0.23 0.16 0.16 0.06 1977 3.47 2.97 1.92 0.96 0.70 0.21 1978 0.44 0.38 0.23 0.14 0.12 0.05 1979 3.32 2.85 1.73 0.87 0.63 0.19 1980 1.09 0.94 0.56 0.31 0.28 0.10 1981 0.30 0.26 0.18 0.13 0.12 0.04 1982 1.20 1.04 0.85 0.55 0.51 0.16 1983 0.29 0.25 0.19 0.12 0.13 0.05 1984 1.17 1.01 0.65 0.47 0.44 0.15 1985 0.96 0.83 0.54 0.38 0.30 0.10 1986 0.28 0.25 0.16 0.13 0.11 0.04 1987 0.83 0.72 0.52 0.36 0.36 0.12 1988 2.92 2.50 1.46 0.72 0.53 0.17 1989 0.73 0.64 0.41 0.23 0.18 0.06 1990 0.41 0.35 0.21 0.13 0.11 0.04

Sorted results

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly 0.03 3.69 3.16 1.93 1.00 0.78 0.24



### 210.06 3.57 3.14 1.92 0.96 0.70 0.21 0.10 3.47 2.97 1.84 0.89 0.64 0.19 0.13 3.32 2.85 1.73 0.87 0.63 0.19 0.16 2.92 2.50 1.46 0.72 0.53 0.17 0.19 1.63 1.41 0.97 0.55 0.51 0.16 0.23 1.40 1.23 0.85 0.54 0.47 0.16 0.26 1.20 1.04 0.77 0.47 0.44 0.15 0.29 1.17 1.01 0.65 0.39 0.36 0.12 0.32 1.09 0.94 0.56 0.38 0.33 0.11 0.35 0.96 0.83 0.54 0.36 0.30 0.10 0.39 0.83 0.72 0.52 0.34 0.28 0.10 0.42 0.75 0.65 0.42 0.31 0.27 0.08 0.45 0.74 0.64 0.41 0.29 0.23 0.08 0.48 0.74 0.64 0.38 0.24 0.19 0.06 0.52 0.73 0.64 0.38 0.23 0.18 0.06 0.55 0.59 0.50 0.37 0.22 0.17 0.06 0.58 0.55 0.48 0.30 0.21 0.16 0.06 0.61 0.50 0.43 0.29 0.18 0.16 0.06 0.65 0.44 0.38 0.28 0.17 0.15 0.05 0.68 0.41 0.37 0.24 0.16 0.14 0.05 0.71 0.39 0.35 0.23 0.15 0.14 0.05 0.74 0.36 0.31 0.23 0.14 0.13 0.05 0.77 0.35 0.31 0.21 0.14 0.13 0.05 0.81 0.30 0.26 0.19 0.13 0.12 0.05 0.84 0.29 0.25 0.18 0.13 0.12 0.04 0.87 0.28 0.25 0.17 0.13 0.11 0.04 0.90 0.27 0.24 0.16 0.12 0.11 0.04 0.94 0.19 0.17 0.13 0.09 0.08 0.03 0.97 0.15 0.13 0.08 0.07 0.06 0.02

0.10 3.46 2.96 1.82 0.89 0.64 0.19 Average 0.09429 ofyearly 1 averages

Inputs generated by pe5.pl

- Novemeber 2006

Data used for this run: Output File: FLCitrus_DW_01-03 Metfile: w12844.dvf PRZM FLcitrusSTD.txt scenario: EXAMS ir298.ex environ v



### 22ment file: Chemica Diflubenzuron I Name: Descripti Variable Value Units Comments
on Name Molecul mwt 311 g/mol
ar weight Henry's henry 1.87E-09 atm-mA3/mol Law Const. Vapor vapr 9.00E-10 torr Pressure Solubilit sol 0.08 mg/L y Kd Kd mg/L Koc Koc 3961 mg/L Photolys kdp 80 days Half-life is halflife Aerobic kbacw 25.2 days Halfife Aquatic Metaboli
sm Anaerob kbacs 102 days Halfife ic Aquatic Metaboli
sm Aerobic asm 5.11 days Halfife Soil Metaboli sm Hydrolys pH 7 119 days Half-life is: Method: CAM 2 integer See PRZM manual lncorpor DEPI em ation Depth: Applicati TAPP 0.35 kg/ha on Rate: Applicati APPEFF 0.99 fraction
on Efficienc y: Spray DRFT 0.01 fraction ofapplication rate applied to pond Drift



### 23Applicati Date 3-Jan dd/mm or dd/mmm or dd-mm or dd-mmm
on Date Interval interval 30 days Set to 0 or delete line for single app. 1 app. rate apprate kg/ha 1 Interval interval 30 days Set to 0 or delete line for single app. 2 app. rate apprate kg/ha 2 Record FILTRA 17: IPSCND 1 UPTKF Record PLVKRT 18: PLDKRT FEXTRC 0.5 Flag for IR Reservoi Index r Res. Run Flag for RUNOFF total none, monthly ortotal(average ofentire run) runoff calc.



### 24

### Example of PRZMOutput forDrinking WaterExposure (CPU) stored as CPU_DW_30-06 .out Chemical: CPU PRZM environment: FLcitrusSTD.txt,modified Tueday, 29 May 2007 at 12:45:56 EXAMS environment: ir298.exv, modified Tueday, 26 August 2008 at 05:14:08 Metfile: w12844.dvf, modified Tueday, 26 August 2008 at05:14:22

Watersegment concentrations (ppb) Year Peak 96 hr 21 Day 60 Day 90 Day Yearly 1961 0.34 0.32 0.27 0.20 0.19 0.07 1962 1.15 1.10 0.87 0.60 0.52 0.28 1963 2.19 2.04 1.61 1.09 0.93 0.43 1964 2.32 2.18 1.80 1.43 1.33 0.72 1965 2.80 2.57 2.24 1.71 1.40 0.82 1966 1.67 1.57 1.42 1.24 1.19 0.93 1967 1.73 1.62 1.30 1.09 0.97 0.72 1968 2.46 2.29 1.92 1.48 1.32 0.80 1969 1.59 1.50 1.31 1.22 1.12 0.79 1970 0.86 0.82 0.76 0.71 0.72 0.60 1971 1.42 1.31 1.00 0.70 0.61 0.42 1972 1.56 1.45 1.16 0.89 0.81 0.57 1973 1.02 0.98 0.85 0.81 0.73 0.54 1974 1.49 1.38 1.11 0.82 0.73 0.53 1975 2.08 1.90 1.51 1.04 0.89 0.51 1976 1.44 1.36 1.08 0.92 0.87 0.56 1977 2.72 2.51 1.98 1.35 1.16 0.67 1978 1.54 1.47 1.23 0.92 0.85 0.63 1979 2.75 2.51 2.08 1.51 1.29 0.71 1980 1.05 0.99 0.92 0.79 0.72 0.62 1981 1.68 1.59 1.27 1.13 1.05 0.59 1982 1.89 1.77 1.52 1.13 1.02 0.71 1983 1.70 1.57 1.22 1.05 0.94 0.72 1984 1.98 1.85 1.44 1.02 0.93 0.67 1985 1.20 1.12 0.99 0.78 0.76 0.61 1986 1.02 0.96 0.79 0.70 0.64 0.51 1987 1.78 1.64 1.33 1.15 1.02 0.58 1988 2.31 2.12 1.59 1.16 1.06 0.70 1989 0.63 0.62 0.60 0.57 0.55 0.48 1990 1.80 1.66 1.43 1.05 0.94 0.54

Sorted results

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly 0.03 2.80 2.57 2.24 1.71 1.40 0.93 0.06 2.75 2.51 2.08 1.51 1.33 0.82



### 250.10 2.72 2.51 1.98 1.48 1.32 0.80 0.13 2.46 2.29 1.92 1.43 1.29 0.79 0.16 2.32 2.18 1.80 1.35 1.19 0.72 0.19 2.31 2.12 1.61 1.24 1.16 0.72 0.23 2.19 2.04 1.59 1.22 1.12 0.72 0.26 2.08 1.90 1.52 1.16 1.06 0.71 0.29 1.98 1.85 1.51 1.15 1.05 0.71 0.32 1.89 1.77 1.44 1.13 1.02 0.70 0.35 1.80 1.66 1.43 1.13 1.02 0.67 0.39 1.78 1.64 1.42 1.09 0.97 0.67 0.42 1.73 1.62 1.33 1.09 0.94 0.63 0.45 1.70 1.59 1.31 1.05 0.94 0.62 0.48 1.68 1.57 1.30 1.05 0.93 0.61 0.52 1.67 1.57 1.27 1.04 0.93 0.60 0.55 1.59 1.50 1.23 1.02 0.89 0.59 0.58 1.56 1.47 1.22 0.92 0.87 0.58 0.61 1.54 1.45 1.16 0.92 0.85 0.57 0.65 1.49 1.38 1.11 0.89 0.81 0.56 0.68 1.44 1.36 1.08 0.82 0.76 0.54 0.71 1.42 1.31 1.00 0.81 0.73 0.54 0.74 1.20 1.12 0.99 0.79 0.73 0.53 0.77 1.15 1.10 0.92 0.78 0.72 0.51 0.81 1.05 0.99 0.87 0.71 0.72 0.51 0.84 1.02 0.98 0.85 0.70 0.64 0.48 0.87 1.02 0.96 0.79 0.70 0.61 0.43 0.90 0.86 0.82 0.76 0.60 0.55 0.42 0.94 0.63 0.62 0.60 0.57 0.52 0.28 0.97 0.34 0.32 0.27 0.20 0.19 0.07

0.10 2.69 2.49 1.97 1.47 1.32 0.80 Average 0.60 ofyearly averages

Inputs generated by pe5.pl- Novemeber 2006

Data used for this run: Output File: CPU_DW_30-06 Metfile: w12844.dvf PRZM FLcitrusSTD.txt scenario: EXAMS ir298.ex environ v ment



### 26file: Chemica CPU I Name: Descripti Variable Value Units Comments
on Name Molecul mwt 170.6 g/mol
ar weight Henry's henry 1.49E-10 atm-m"3/mol Law Const. Vapor vapr 1.65E-04 torr Pressure Solubilit sol 1770 mg/L y Kd Kd mg/L Koc Koc 3961 mg/L Photolys kdp 0 days Half-life is halflife Aerobic kbacw 

### 222 days Halfife Aquatic Metaboli
sm Anaerob kbacs days Halfife ic Aquatic Metaboli
sm Aerobic asm 111 days Halfife Soil Metaboli
sm Hydrolys pH 7 0 days Half-life is: Method: CAM 

### 2 integer See PRZM manual lncorpor DEPI em ation Depth: Applicati TAPP 0.072 kg/ha
on Rate: Applicati APPEFF 1 fraction
on Efficienc y: Spray DRFT 0 fraction ofapplication rate applied to pond Drift



### 27Applicati Date 30-06 dd/mm or dd/mmm or dd-mm or dd-mmm
on Date Interval interval 30 days Set to 0 or delete line for single app. 1 app. rate apprate kg/ha 1 Interval interval 30 days Set to 0 or delete line for single app. 2 app. rate apprate kg/ha 2 Record FILTRA 17: IPSCND 1 UPTKF Record PLVKRT 18: PLDKRT FEXTRC 0.5 Flag for IR Reservoi Index r Res. Run Flag for RUNOFF total none, monthly ortotal(average ofentire run) runoff calc.



### 28

### Input and Output ofAgDRIFT Modeling

Title Untitled
Combination Orchards 

### r Normal (Stone and Pome FruitVineyard) 

### r. Qense (Citrus, Tall Trees) 

### r ,S_parse [Young, Dormant) 

### r Y:ineyard r 4 .Qrchard Information Dense (Citrus, Tall Trees) This composite orchard combines Almond, Orange, Grapefruit Small Grapefruit (mist blower). and Pecan orch11rds. Mean deposition Application Efficiency(%) (20 rows): 98.01 E**~tended** Settings I 8ccess**E~tended** Settings



### r r r r r 

### r r 

### r r r 

### r

' Aquatic Assessment 

### 15<1

Aquatic Body Definition



### r. EPA-Defined Pond r EPA-DefinedWetland


### r User-definedWater Body DownwindWater BodyWidth: 1208.7 ft Average Depth: 16.56 ft

Tier I Settings Active Rate: lo.3125 lb/ac
Calculations Distance ToWater Body From 

### l25

Edge ofApplicationArea:

InitialAverage

Deposition:

InitialAverage Concentration: looo74

1130.4 ft

Fraction ofApplied g/ha l00023

ng/l (ppt) lb/ac



# _j_j Erl.nt 

### jjr,

....r.::.i'c

......

### ,,l

.....**!!!.~**.......; CIOSi!



### 29

## AppendixB. Avian and MammalianRisk Quotient Calculations for Diflubenzuron Based on T-REX

Upper Bound Kenaga Residues For RQ Calculation

Chemical Name: Diflubenzuron Use 0 Fotttlulatlon 0**APillitt~tlon ~btl!**  0.3215 lbs a.i./acre H11lf-llfu 3S days APillitiltiOh lhtllf\1111 30 days**M~Mimmtlll** Apps.!Year 3 Length of Slmul11tlon 1 year**V~:~rll!ble** IIPPIItatlon rates? no endpoints Red-wing blackbird LD50 (mg/kg-bw)

Bobwhite quail LC50 (mg/kg-diet) Avian Mallard duck NOAEL(mg/kg-bw)

Bobwhite quail NOAEC (mg/kg-diet)

LD50 (mg/kg-bw) Mammals LC50 (mg/kg-diet) NOAEL (mg/kg-bw) NOAEC lmu/ku-diet Dietary-baaed EECs (ppm) Kenaga Values Short Gtllss 143.27 Tllll Gtass 65.67**Elto:H!dle~f** plahts 80.59 Ftlllt&fpl:ld&iseeds 6.95 Arthropods 56.11



### 30 3763.00

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0.00 0.00 250.00 5000.00 Acute and Chrome ROs are l:laseel on tne Upp Kenaga Residues The maximum smgle day res1due est1rnanon 1S both the acute and reproduct1on ROs
RQs reported as "0.00" in the RQ t <0.01 in your assessment. This is figure issues in Excel.

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### Avian Results

Dose-baaed EECs (mgikg>bw) Short Gnus Tall Grass Elroadl<!al plat1ts FtltitsiiHlils Arthropods S<!<!ds



### Dose-based RQs (bbn·band EEC/adjuated L060)
ISMrt Gr!lss Tall Gr!lss Elrol!ill<!tlf**plt~nts** Ftltitslpoils Arthropods**S~<!ds** 

### Dietary-based RQs

Short Grass Tall Grass aroadleaf plants FruitsltJodslseads Arthropods Avian Cle• Small Mid Large

Granivores

20 100 1000 Adjusted lD50

3254.92 4143.68 5853.11
Avian Cllll$8$ end Body Weiahtll smell mid

20 100 163.11 93.05 74.79 42.65 91.78 52.34 10.20 5.82 63.91 36.44 2.27 1.29

Avian Acute RQs Size Class (grams) 20 100 0.05 0.02 0.02 0.01 0.03 0.01 0.00 0.00 0.02 0.01 0.00 0.00

RQs

Acute Chronic #DIVIO! 0.29 #DIVIO! 0.13 #DIVIO! 0.16 #DIV/0! 0.02 #DIVIO: 0.11**t·Jtt~** Tt ptO<Id<l**rl~k** management Mh the maxtmum eOssible Information 1t**~~ t€ttJinm~nd~d**  that both the dose-based and concentratiCn-based**RC~ 1:~**  teltulehod**·.';h~n** data are acatlable



### 31 loremsl large 1000 41.66 19.09 23.43 2.60 16.32 0.58

1000 0.01 0.00 0.00 0.00 0.00 0.00 Ingestion (Fwetl %body wgt consumed 114 65 29 25 14 6 2.28E.02 6.49E.02 2.91E-01 5.Q6E.03 1.441:.02 6.46E.02**r------------------------------------~---~----~-------~-----** t:llllubl!hzlltoh u Mammalian Results

Mammalian Body Ingestion (FdiYl**lnge~~;.~~wet)** Cless Weiaht ia bwt/devl 15 3 14 Herbivores/ 35 5 23 insectivores 1000 31 153 15 3 3 Grainvores 35 5 5 1000 31 34

Mammalian Body Adjusted Adjusted Cless Welaht LD50 NOAEL 15 0.00 549.46 Herbivores/ 35 0.00 444.57 insectivores 1000 0.00 192.29 15 0.00 549.46 Granivores 35 0.00 444.57 1000 0.00 192.29

Dose-Based EECs MemmellenCl•-•end Body weight
rams

ort Gnus Ti!ll Gtilss ElttH!ttll!llfplllhts Ftllltslpotls Arthropods Sl!l!tls



### Dose-based RQs Dose-based EEC/LD50 or

ort Gress Tall Grass Broadleafplants Fruits/pods Arthropods Seeds 15 136.60 62.61 76.84 8.54 53.50 1.90

Smell mammal 15 rams Acute #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! 35 94.41 43.27 53.10 5.90 36.98 1.31



### Dietary-based RQs (Dietary-based EEC/LC50 or NOAEC Acute Chronic Short Gtllss Tllll Grass Btolltlll!llfplants Ftuitslpotlslsl!l!tls Arthto otls #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0!**Not~** To**pro\·ld~** risk**hlShS9~hl~nt** With**th~** max1mum possible information ills**rettlhlhl~nded** thst both**th~** dose·bssed snd concentration·based R09 be tsltuleted when dsts sre svsilsble 0.03 0.01 0.02 0.00 0.01



### 32 1000 21.89 10.03 12.31 1.37 8.57 0.30

Medium mammal 35 %bodywgt COMilmild 95 66 15 21 15 3

#OIVIO! #OIVIO! #OIVIO! #DIViO! #OIVIO! IIOIVIO! Fl fko..fllttfiii•YI

1.43L02 2.3110-02 ·1.5310.01 3.1810-03 5 1310.03 3.4oi0.02