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



### MEMORANDUM OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION



### September 19, 2012 PC Code: 044312 DP Barcode: D398677

SUBJECT: FIFRA Section 3 New Use Environmental Risk Assessment for the Registration of Dinotefuran for Rice.

TO: Venus Eagle, Risk Manager Rita Kumar, Risk Manager Reviewer Insecticide-Rodenticide Branch Registration Division (7505P**---~** 

### THROUGH: Dana Spatz, Branch Chief Rosanna Louie-Juzwiak, RAPL Environmental Risk Branch III

FROM:

SUMMARY Environmental Fate and Effects Division (7507P)

Frank T. Farruggia, Ph.D., Biologist James K. Wolf, Ph.D., Environmental S Environmental Risk Branch III Environmental Fate and Effects Division (7507P)

EFED has conducted an ecological risk assessment for the insecticide dinotefuran (CAS No. 165252-70-0) and the proposed Section 3 new use on rice to control Rice Stink Bug. Dinotefuran is a nitroguanidine insecticide and the active ingredient in the product LX434 Dinotefuran 20SG (altemant name: TENCHU 20SG) Insecticide (EPA Reg. No. 86203-25). This assessment builds

on several previous ecological assessments (Table 

### 1), and relies on a summary of ecological effects, environmental fate and physical chemical properties data from those assessments. Based

on the available invertebrate toxicity data, dinotefuran is very highly toxic to terrestrial and aquatic insects and invertebrates. These organisms may be impacted from the proposed of the dinotefuran new use on rice; however, because the proposed dinotefuran application timing would be post flowering, pollinator 

### (e.g. pollen harvesting insects) exposures in the field are

### 2 expected to be minimal. Invertebrates resi dent in the field or visiting the field ( e.g. for food, water, shelter, or resting) would be considered at risk. There is also a potential for off-site exposure from spray drift to pose a concern for te rrestrial and aquatic in sects and invertebrates from spray drift. With the exception of concerns for risks to terrestrial and aquatic invertebrates, there are generally no risks of c oncern for exposures to terrestria l or aquatic animals or plants from the proposed dinotefuran use on rice.

Table 1. Past Risk Assessments on Dinotefuran. Addi tional summary information is provided in the recent problem formulation for Registration Review (DP Barcode: D389547, 2011).

DP Barcode Year Use site Target Pest Action

285633 2004 Leafy vegetables, turfgrasses, ornamentals, residential use Various (e.g., ants, flies, cockroach, etc.) Section 3: New Chemical

304957 2004 Cotton, potato, head and stem brassica, fruiting vegetables

, cucurbits , grapes, ornamental plants and flower beds, lawn, shrubs and additional residential uses Various Section 3: New Use

324854 2006 Head and stem brassica, cucurbits, fruiting vegetables, grapes, leafy vegetables, potatoes Various Section 3: New Use (increasing use rates) 332829 2006 Leafy Brassica Sweet potato whitefly biotype B ( Bemisia tabaci ) Section 18

355010 2008 Rice Rice stink bug Section 18 358860 2009 Leafy Brassica Greens (Subgroup 5B), including turnip greens Various IR-4 Petition: Incremental Environmental RA 378125 2011 Forestry Uses (Christmas trees, trees in plantations, reforestation nurseries, forests, woodland areas) Various Section 3: New Use

388997+ 2011 Stone and pome fruit Brown marmorated stink bug Section 18

390191 2012 bulb and green onion subgroups, low growing berry, small fruit and vine climbing (berry) subgroup, tuberous and corm vegetables subgroup, watercress, and peach. Various Section 3

+ 390375, 390381, 390380, 390376, 389144, 390383, 390382, 390379, 390378, 390377, 389436, 390903, 390904



### Data Uncertainties and Data Gaps

The available studies have provided suitable info rmation for completing the environmental fate and effects risk assessment for the proposed ne w use on rice. For a comprehensive description and justification of data gaps and data n eeds for the upcoming dinotefuran reregistration schedule see the most recent problem formulation for Registration Review document ( i.e. , Tables 17-18 and text succeeding the tables, Appendi ces C and D in DP Barcode DP389547, December 13, 2011).

### 3 PROBLEM FORMULATION

The environmental fate and toxicity of dinotefuran have been discu ssed in depth in previous risk assessments ( e.g. , DP285633, 2004; DP332829, 2006; and DP378125, 2011). The registrant submitted two environmental fate guideline studies 1 

### to address three data requirements 2 

### : (1) aerobic aquatic metabolism and (2) anaerobic aq uatic metabolism, and (3) freezer storage stability identified in the Data Call-In (GDCI-044312-1147).

Mode of Action

Dinotefuran, also known as MTI-446, is a broad- spectrum, systemic furanicotinyl insecticide belonging to the 4A nitroguanidine class of chemicals and a memb er of the neonicotinoids that were developed as an analog of nicotine. Dinotefuran acts as an agonist at ( i.e., it binds to) the nicotinic acetylcholine receptor (nAChR) to wh ich the neurotransmitter acetylcholine (ACh) would otherwise bind. Acetylcholine (ACh) is the endogenous agoni st and excitatory neurotransmitter of the cholinergic nervous system. Therefore, dinotefuran acts on the autonomic nervous system by binding to the postsynaptic nicotinic acetylcholine receptor. Although the cholinesterase enzyme itself is not affected by dinotefuran, the nerve is continually stimulated, and the end result, paralysis and death, is similar to that caused by cholinesterase inhibitors. Dinotefuran is highly wate r soluble (39,830 mg/L @20 o 

### C) and is readily tr anslocated in plant tissue giving it good systemic activity. Dinotefur an has stomach and contact activity and is effective against a wide variet y of insects includi ng aphids, whiteflies, thrips, leafhoppers, leafminer, sawflies, mole crickets, white gr ubs, lacebugs, billbugs, beetles, mealybugs, stink bugs, weevils, and cockroaches.

Use Characterization

A complete summary of the use patterns assessed in the past for dinotefuran is available in the recent problem formulation for Registration Review (see Table 3 of DP Barcode: DP389547, 2011) and FIFRA Section 3 New Use Envir onmental Risk Assessments (DP Barcode: DP390191). A cross-section of the registered agri cultural use site s includes cucurbits, grapes, pineapple, bulbs and green onions , low growing berries, small fr uit and vine climbing berries, tuberous and corm vegetables, watercress, p each, nut trees, fruiting vegetables, brassica vegetables, and leafy vegetables . Non-agricultural use sites in clude forest trees, ornamental plants (flowering and foliage plan ts, woody shrubs, vines, and trees ), ornamental lawns and turf, pets and pet premises, animal premises, domestic dwellings, picnic areas, transportation vehicles, food handling establishments, hospitals, and co mmercial/institutional/industrial buildings. In addition to its registered uses there is an active Section 18 3 

### for use on rice in Texas.

The proposed maximum single aerial applicati on rate is 0.131 pound of active ingredient per acre (lb a.i./A), with a maximum of two app lications, and a 7-day minimum reapplication interval. In regions where two ha rvests can be produced within a single year, the grower can split the applications to one per crop or combine them to a single harvest. This application rate

1 MRIDs 48680002 and 48680003

2 OCSPP Guideline Nos. 835.4400, 835.4300 and 860.1380
3 EPA File No. 12TX04, EPA Establishment No. 39578-TX-1 (03/01/12).

### 4 for the proposed use is lower than previously assessed uses; namely, use on turfgrass as 0.54 lb a.i./A (DP 285633, 2004). A detailed summary of th e proposed use pattern addressed in this assessment is shown in Table 2.

Table 2. Proposed New Uses for Dinotefuran

Crop/Site Application Type/ Method Single Application Rate Range

(lb a.i./A) Maximum Application Rate Per Year

(lb a.i./A) Maximum Number of Applications

Rice Aerial Spray 0.09375 – 0.131 0.262 2



### The proposed label indicates the ti ming of applications and use of the higher specified rates are triggered by the severity and uni formity of pest pressure.

ENVIRONMENTAL FATE SUMMARY

The physico-chemical and environmental fate an d transport properties of dinotefuran and its transformation products are discu ssed in detail in the Registration Review: Problem Formulation for Environmental Fate, Ecological Risk, Enda ngered Species, and Drinking Water Exposure Assessments for Dinotefuran December 13, 2011 (DP389547) and the new chemical chapter of June 30, 2004 (DP285633). Since these reviews, the registrant has submitted two environmental fate guideline studies 4 

### to address three data requirements 5 

### : (1) aerobic aquatic metabolism and (2) anaerobic aquatic metabolism, and (3) freezer storage stability identified in the Data Call-In (GDCI-044312-1147). Only the physico-chemical and environmental fate properties of dinotefuran and the transformati on/degradation product DN are presen ted here as it is included in the human drinking water assessment (DP397490).

Physico-chemical Properties

Dinotefuran has a molecular weig ht of 202.2 g/mole, a very high water solubility (39,830 mg/L), and a low octanol/water partition coefficient (K ow 

### = 0.283; log K ow 

### = -0.549), suggesting a potential for low bioaccumulation. The low vapor pressure (1.275 x 10 -8 

### mm Hg) and a low Henry’s Law Constant (8.63 x 10 -14 

### atm • M 3 

### /mol) suggest that this compound is not expected to volatilize substantially from water or soils in the environment. The selected physico-chemical properties of dinotefuran are listed in Table 3

.

Table 3. Physico-chemical Properties for Dinotefuran

Parameter Value Reference/ Comments
Selected Physicio Chemical Parameters
Chemical Classification Nitroguanidine
Pesticide Classification Systemic Insecticide

4 MRIDs 48680002 and 48680003

5 OCSPP Guideline Nos. 835.4400, 835.4300 and 860.1380

### 5 Table 3. Physico-chemical Properties for Dinotefuran

Parameter Value Reference/ Comments
Molecular Weight 202.2 g/mol MRID # 45640101
Water Solubility (20 o C) 39,830 mg/L MRID# 45640112
Vapor pressure (30 o C) <1.275x10 -8 mm Hg (equivalent to <1.7 x 10 -6 Pa) MRID# 45640105
MRID# 45639702
Henry's Law Constant 8.63 x 10 -14 Atm m 3 /mol Calculated
Octanol/Water Partition, K ow 0.283 @25 o C MRID # 45639702
log K OW -0.549 MRID # 45639702
Dissociation constant (pKa) 12.6 @20 o C (estimated) MRID # 45639702
Melting point 107.5 o C MRID # 45639702
pH 5.6 @25 o C MRID # 45654201
Density 1.40 g/cm 3 @20 o C MRID # 45639702



### Fate properties

The degradation products of dinotefuran are shown in Table 4. DN, UF, MG hydrogen chloride, DN-2-OH+DN-3-OH, and BCDN succi nate are major degradation products in aquatic environments. These degradation pr oducts are formed through metabolism ( i.e., DN) or photodegradation ( i.e. , DN, UF, MG hydrogen chloride , DN-2-OH+DN-3-OH, and BCDN). MNG, is the major degradation product in soil but not in the aquatic metabolism studies.

Table 4. Dinotefuran Degradates Identified in Environmental Fate Studies

Short

names Structure Study Name Results (calculated or observed halflife, degradates, and quantities, in % applied)

DN 1 Anaerobic Soil Metabolism Maximum 29.2% at 120 days in Switzerland soil

Aerobic Aquatic Metabolism Maximum 23.1% at 180 days in river system and 32.6% at 103 days in pond system
For the silt loam and sand sediment systems, the major product DN was detected at maximums of 69.2-69.6% and 39.6-47.4% of the applied, respectively, at study termination.

Anaerobic Aquatic Metabolism For the silt loam and sand sediment systems, the major product DN was detected at maximums of 70.7-74.4% and 60.5-66.3% of the applied, respectively, at study termination. O N H

NH N H CH 3

H 3 PO 4

### 6 Table 4. Dinotefuran Degradates Identified in Environmental Fate Studies

Short

names Structure Study Name Results (calculated or observed halflife, degradates, and quantities, in % applied)
Photolysis in Water Maximum 7.5% at 11 days

UF Photolysis in Water Maximum 10.6% at 13.8 days (last test interval)

MG hydrogen chloride Photolysis in Water Maximum 10.2% at 1.8 days, and 0.8% at 13.8 days (final sampling interval)

DN-2-OH
+
DN-3-OH Photolysis in Water Maximum 28.2% at 13.8 days (study termination)

BCDN Succinate Photolysis in Water Maximum 16.1% at 1.8 days and 4.5% at 13.8 days (study termination)

MNG Aerobic Soil Metabolism Maximum 23.96% at 42 days (preliminary study) Maximum 13.7% at 225 days (conducted on radiolabeled parent), study termination

Terrestrial Field Dissipation Maximum 31.5% at 45 days after 2 nd application; study termination at 170 days after 2 nd application

1 DN phosphate (1-methyl-3-(tetrahydro-3-furylmethyl)guanidinium dihydrogen phosphate) was identified as a degradation product of dinotefuran in photodegradation in soil (MRID 45640109), photodegradation in water (MRID 45640106, 45640105) and anaerobic soil metabolism (MRID 45891616) studies. Although the phosphorus is not an elemental constituent of parent dinotefuran, DN phosphate was formed as a salt of orthophosphate and 1- methyl- 3-(tetrahydro-3-furylm ethyl)guanidinium. Because the DN phosphate salt will dissociate in soil and aquatic environments to form (1-methyl-3-(tetrahydro-3-furylmethyl)guanidinium) and phosphoric acid, it is not expected to alter the environmental fate or toxicity of the organic moiety of DN phosphate (1-methyl-3-(tetrahydro-3- furylmethyl)guanidinium).



### Environmental fate properties for dinotefuran are shown in Table 5.

Table 5. Environmental Fate Properties for Dinotefuran

Parameter Value Reference/ Comments
Hydrolysis Half-life stable MRID# 45640102 (s) MRID# 45640102 (a)
Photodegradation in Water Half-life 1.8 days MRID# 45640105 (s)

Aerobic Soil Metabolism Half-life 38, 17, 78, 89, 63, 100, 87.7, and 15.9 days MRID# 45640111 (s) MRID# 45640112(s) O N H

O N H CH 3

NH N H N H 2 CH 3

ClH

O H N NH

HN OH COOH

COOH 2

N H N O

N H CH 3 COOH

COOH

N H N H 2

N CH 3

NO 2

### 7 Table 5. Environmental Fate Properties for Dinotefuran

Parameter Value Reference/ Comments MRID# 46751101(a) MRID# 45640112(a) MRID# 46711201 (s)
Anaerobic Soil Metabolism Half-life 65 days MRID# 45891616 (s)
Aerobic Aquatic metabolism Half-life 79.3 days 76.0 days
25.7 – 27.3 silt loam
66.6 – 50.2 sand MRID # 45640117 (s)

MRID # 48680002 (s)

Batch Equilibrium Texture Kd Koc
Loam 1.01 42 Sandy Loam 0.71 45 Clay Loam 1.22 42 Loamy Sand 0.12 6
Silt Loam 0.22 22 MRID# 45640114 (a)

Terrestrial Field Dissipation CA (SL) t 1/2 = 65.2 days MNG (degradate) was detected in 0-15 cm soil at 31.5% @ 45 days after 2nd application.
GA (SL) t 1/2 = 19.4 days
MNG was detected in 0-15 cm soil at 5.3% max. mean concentration after 7 and 30 days after the 2 nd application.
NY (SL) t 1/2 = 55.9 days
MNG was detected in 0-15 cm soil at 6.6% @ 45 and 120 days after the second application. Applied 2X @ 0.268 lb a.i/A @ 14-day interval to bare soil. MRID# 45640118 (a)

Accumulation in Fish, max. BCF NA Waived (K OW = 0.28)
* (a) = acceptable study that fulfills guideline requirement; (s) = supple mental study; NA=Not Available; N/A=Not Applicable



### Based upon the results of an additional aerobi c and anaerobic aquatic metabolism study (MRID 48680002; supplemental study) the majo r transformation product in an aquatic environment such as a rice paddy would be DN. At the termination of this study, 77 to 86 percent of the applied radioactivity was identified as dinotefuran or DN; no other de gradation products (except CO 2 

### ) were identified. Of these degradates important tr ansformation products in the environmental fate studies of dinotefuran appear to be MNG and DN. The aqueous photolysis study had identified UF, DN-2-OH+DN-3-OH, MG hydrogen chloride, a nd BCDN succinate as major transformation products, only two (UF, DN-2-OH+DN-3-OH) of these degradates were identified as residues of

concern.

### 8 For the proposed rice use, the relevant environm ental fate properties are those associated within the aquatic environment. With an aqueous photol ysis half-life of 1.8 da ys, aqueous photolysis could be important in clear and shallow bodies of water; however, in rice paddies, deep ponds or rivers or flowing bodies of wate r, it is more likely to dissipat e via dissolution, and subsequently via metabolism. Based upon this it is assumed that aqueous photolysis would not contribute significantly to the degradation of dinotefuran; thus the formation of these photodegradates would be expected to be minor (see Table 4 ). The residues of con cern for the drinking water assessment for the proposed rice use were dinotefuran and DN (DP397490).

The previous aerobic aquatic and anaer obic aquatic metabolism study (48681616) was determined to be supplemental, in part, because the sediment was determined to be anaerobic during the aerobic portion of the study. In another aerobi c and anaerobic metabolism study (MRID 48680002), the half-lives of parent dinot efuran were similar for each soil ( i.e., textural class: silt loams~25 days and sand >50 days) ( Table 6 ). The major degradate in the aquatic dissipation studies was DN, which was still increasing at the end of the study, so half-lives for DN could not be determined. Half-lives (and rate constants), for modeling, were determined for the decline of the parent plus DN (based upon % applied radioactivity), for aerobic aquatic (352 and 685 days) and anaerobic aquatic (188, 468, 510 days) metabolism for the combined dinotefuran plus DN residues.

Table 6 . Summary of half-life and degradation rates for Dinotefuran and Dinotefuran + DN in total system of Aerobic and Anaerobic Metabolism to address OCSPP No. Guideline Studies 835.4300 and 835.4400. (Tables 2 and 3 in DP397490)

MRID (condition) Soil in Soil/Water

System Dinotefuran Dinotefuran + DN

48680002 Half-life 1 (day) Rate (1/day) Half-life 1 (day) Rate (1/day)
(Aerobic) Silt loam 25.7 0.027 685 0.00101
(Aerobic) Sand 66.6 0.0104 352 0.00197
(Anaerobic) Silt loam 27.3 0.0254 468 0.00148
(Anaerobic) Sand 50.2 0.0138 509 0.00136

45891616 Silt loam 66.84 2 0.01037 188 0.0037 (Anaerobic)

1 Kinetics model: Single First-Order (SFO) using regression in data analysis of Microsoft Excel 2007 2 Half-life value in D354339 is 65 days.

3 90-percent upper bound means of aerobic and anaerobic aquatic degradation rates for Dinotefuran + DN is 1031.9 days (0.000167 days -1 ) and 579.3 days (0.00119 days -1 ), respectively.



### In the soil, dinotefuran appears to be relatively persistent to meta bolism, both in aerobic (half-life = 63-100 days) and anaerobic soil (half-life = 65 days) conditions . It appears that under metabolic conditions, dinotefuran degrades to M NG and subsequently to NG. Dinotefuran is

### 9 stable to hydrolysis in a range of pH values of 4 to 9. It is co nsidered to be mobile to highly 6,7 

### mobile (K oc 

### = 6 to 45) in various soil types. It is also very high ly soluble (39,830 ppm). Since dinotefuran may persist in soils, it may have a high potential to leach to subsurface. Furthermore, it can migrate to adjacent bodies of water through spray drif t and in runoff events, probably dissolved in the water column.

The batch equilibrium - adsorption/desorption studies conducted on the parent and major degradates MNG and DN-phosphate , indicate that the parent dinotefuran, and MNG are very highly mobile (K oc 

### <50), while DN is slightly to highly mobile. K oc 

### values for dinotefuran ranged from 6 to 45 for eight soils tested (four from Japan and four domestic). K oc 

### values for MNG ranged from 8 to 31 for five domestic and foreign soils. The study on DN-phosphate yielded a wide range of K oc 

### values (between 58 and 2502). Theref ore, parent dinotefuran is more mobile then the transformation product DN.

Environmental fate properties for DN (i n its stable form, DN-phosphate) DN-phosphate 8 

### are shown in Table 7 . Potential routes of dissipation in clude photodegradation, microbial-mediated metabolism, leaching, and runoff. N-phosphate is st able to abiotic hydrolysis at pH 4, 7, and 9). Photodegradation is slow (t 1/2 

### = 53.4 to stable days) in water at pH 5, 7, and 9. It is moderately persistent (t 1/2 

### = 114 days) in soil and aquatic envir onments. DN-phosphate has low soil:water partitioning coefficients (K d 

### < 3; Koc 58-413) in loam and sandy loam textured soils. Higher soil:water partitioning coefficients (K d 

### : 7 - 72; K oc 

### : 270-2502) were found in clay textured soils. These data suggest the extent leaching or runo ff of DN-phosphate is dependent on soil properties such as texture and organic carbon content.

Environmental fate data for th e other degradation products are presented in the new chemical chapter (D285633, June 30, 2004).

6 FAO. 2000. Appendix 2. Parameters of pesticides that influence processes in the soil . In FAO Information Division Editorial Group (Ed.), Pesticide Disposal Series 8. Assessing Soil Contamination. A Reference Manual. Rome: Food & Agriculture Organiza tion of the United Nations (FAO).

7 USEPA. 2006. Standard Soil Mobility Classification Guidance. Memorandum From S. Bradbury to Environmental Fate and Effects Division. January 23, 2004. Environmental Fate and Effects Division. Office of Pesticide Programs. United States Environmental Protection Agency.

8 DN phosphate (1-methyl-3-(tetrahydro-3-furylmethyl)guanidinium dihydrogen phosphate) was identified as a degradation product of dinotefuran in photodegradation in soil (MRID 45640109), photodegradation in water (MRID 45640106, 45640105) and anaerobic soil metabolism (MRID 45891616) studies. Although the phosphorus is not an elemental constituent of parent dinotefuran, DN phosphate was formed as a salt of orthophosphate and 1- methyl- 3-(tetrahydro-3-furylm ethyl)guanidinium. Because the DN phosphate salt will dissociate in soil and aquatic environments to form (1-methyl-3-(tetrahydro-3-furylmethyl)guanidinium) and phosphoric acid, it is not expected to alter the environmental fate or toxicity of the organic moiety of DN phosphate (1-methyl-3-(tetrahydro-3- furylmethyl)guanidinium).

### 10 Table 7 . Physicochemical and Environmental Fate Properties for Dinotefuran Degradation Product DNPhosphate

Parameter Value Reference/ Comments
Selected Physical Chemical Parameters
Water Solubility (20 o C) 619,400 mg/L MRID# 45640112 MRID# 45639702, 45639706, 45639707 (USEPA Pesticide Fact Sheet, 2004)
Hydrolysis Half-life DN-Phosphate pH 4-9 (50 o C) stable MRID# 45640104 (s)

Photodegradation in Water Half-life pH 5 pH7 pH9 53.4 days Stable (533.2 days)
Stable MRID# 45640108 (s)

Aerobic Soil Metabolism Half-life DN 114 days MRID# 45640117 (USEPA Pesticide Fact Sheet, 2004)
Aerobic Aquatic metabolism t 1/2 114 days MRID# 45640117 (USEPA Pesticide Fact Sheet, 2004)
Mobility in Soils DN-Phosphate Texture K d K OC Loam (US) 2.08 87 Sandy Loam (US) 2.07 58 Clay Loam (US) 72.54 2502 Sandy Loam (Swiss) 2.93 413 Clay (German) 7.11 270 MRID# 45640113 (s)

* (a) = acceptable study that fulfills guideline requirement; (s) = suppleme ntal study; NA=Not Available; N/A=Not Applicable



### EXPOSURE MODELING

Aquatic Exposure

For dinotefuran use on rice, applications may l ead to direct surface water contamination as a result of direct spraying of a flooded rice paddy, spray drift or indirect contamination through discharge of the paddy water co ntaining dinotefuran sorbed to suspended soil particles and dissolved dinotefuran. For this assessment a nd the associated Drinking Water Assessment (DP397490), EECs for dinotefuran and relevant de gradates for surface water were obtained using the Tier 1 Rice model v.1.0 9 

### and the modified Tier 1 Rice Model (after D354339, Meléndez, 2009 3 

### ). The modified Tier 1 Rice Mode l v.1.0 assumes that only aerobic and anaerobic aquatic metabolism processes occur in the rice paddy, duri ng the holding period.

9 http://www.epa.gov/oppefed1/m odels/water/rice_tier_i.htm

### 11 Analysis Plan

Tier 1 Rice Model

The EFED Tier 1 Rice Model (v1.0, May 8, 2007) 10 

### was used to estimate aquatic exposures for applications directly to water (floode d field/paddy). The Tier I Rice Model 4 

### v1.0 ( eq. 1 ) is a simple equilibrium partitioning equa tion that calculates a single, screening-level concentration in paddy water and released tail water based on a compound’s application rate and soil mobility.

d ai

w 

### K m C 00013

. 0 00105

. 0 '

  eq. 1



### C wo 

### = C w 

### = water concentration [μg/L]

m ai 

### ' = mass applied per unit area [kg/ha] K d 

### = water-sediment partitioning coefficient [L/kg] K oc 

### = organic carbon partiti oning coefficient [L/kg]

Equation 2 includes the soil proper ty and paddy geometry information to derive eq 1 . The provisionally modified Tier I Rice Model ( eq. 3 ) includes time, the aerobi c degradation rate, and the anaerobic degradation rate as inputs in order to estimate a si ngle, screening-level concentration in paddy water or tail wa ter at a given time after application.



#  

d b sed sed w ai

w 

## K d d m C   3 2



## 10 ' 10

 

##    eq.2

and, if appropriate:

OC d 

## K K 01

. 0 

where: C w 

### = water concentration [μg/L]

m ai 

### ' = mass applied per unit area [kg/ha] K d 

### = water-sediment partitioning coefficient [L/kg] K OC 

### = organic carbon partitioning coefficient [L/kg] d w 

### = water column depth = 0.10 m d sed 

### = sediment depth = 0.01 m θ sed 

### = porosity of sediment = 0.509
ρ b 

### = bulk density of sediment = 1300 kg/m 3

10 USEPA 2007. Guidance for Tier I Estimation of Aqueous Pesticide Concentrations in Rice Paddies . Memo from S. Bradbury to Environmental Fate and Effects Division; May 8, 2007

. U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Environmental Fate and Effects Division, Washington, DC. Available at h ttp://www.epa.gov/oppefed1/models/water/index.htm#rice (accessed September 27, 2010).

### 12 Provisional Modified Rice Model (Jones, 2006).

   

##     t K d d k K d k d k d

w w d b sed sed w d b sed sed sed w



## e C C        

   



 



##   3 3 2 2 1 10 10

0     

### eq. 3 where, t = interval since last application (d) k 1 

### = aerobic aqueous metabolism rate constant (1/days) k 2 

### = anaerobic aqueous metabolis m rate constant (1/days)

The Tier I Rice Model was calibrated to generate estimates that are similar to or greater than dissolved concentrations measured within rice paddies and in discha rged paddy water. The calibration involved determination of the sediment interaction depth by calibrating the model to maximum residues measured in paddy water in dissipation studies. The model does not account for volatilization, dilution, folia r interception, or other dissipati on processes. The model was not evaluated or calibrated for concentr ations measured in sediment.

Detailed descriptions and documentation for the Tier I Rice model can be found on the Office of Pesticide Program’s models website. 11



### Selecting Input Parameters

The input parameters used in this assessment we re selected from the environmental fate data submitted to support dinotefuran registration in accordance with US EPA-OPP EFED water model parameter guidance. 12 

### The input values used in the Tier I rice model are provided in Table 2. The maximum application rate for dinotefu ran for rice is 0.131 lb a.i./A (7.5 oz. to 10.5 oz. product per acre) as an aeria l spray. Two applications per season are allowed. Application rates should not exceed more than a total of 0.262 lb a.i./A per season for aerial applications. The rates for this assessment and the Sec tion 18 (D354339; Meléndez, 2009) are the same.

The only fate data required for th e Tier 1 Rice Model (eq.1) is K d 

### . The average dinotefuran K d 

### is 0.656 mL/g (0.656 L/kg) (Table 5. D354339; Melénd ez, J.L. 2009). The modified Tier 1 Rice model ( eq. 3 ) also requires k 1 

### the aerobic aqueous metabolism rate constant (1/days) and k 2 

### the anaerobic aqueous metabolism rate constant (1/days). These values were determined from the 90 percent upper bound to the aerobic aquatic and anaerobic aquatic metabolism half-lives ( Table 7 ). DN has an average K d 

### of 21.2 L/kg, thus, it has greater sorption potential than the parent (D394848 MRID 45640013).

11 http://www.epa.gov/oppefed1/models/water/index.htm

12 Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides

, Version 2.1, October 22, 2009.

### 13 Surface Water Exposure Estimates
Modeling Data Table 8 summarizes the surface water EECs for dinotef uran and relevant degradate (DN). The surface water EDWCs were obtained using the provisionally modified Tier 1 Rice Model v.1.0 for the use of dinotefuran on rice. The peak concentration is 269 μg/L and the longer term concentration ( ≈ average) would depend upon retention time (10 to 30 days).

Table 8. Tier 1 Surface water EECs (μg/L) for the use of dinotefuran on rice, base d upon total toxic residues (dinotefuran + DN).

Peak 1 Retention Time
10 day 30 day 60 day 100 day 150 day

Dinotefuran + DN 269 257 253 248 240 198

1 At time = 0 peak concentration represents only parent dinotefuran.



### Monitoring Data

Dinotefuran data is not available within the National Water-Quality Assessment Program (NAWQA) database.

Terrestrial

Terrestrial exposure estimates for avian and mamma lian risk assessments were derived using the T-REX model (version 1.3.1, December 22, 2006). Th e EEC values used for terrestrial animal exposure are derived from the Kenaga nomograph, as modified by Fletcher et al. (1994), based on a large set of actual field residue data. The upper limit values from the nomograph represent the 95th percentile of residue values from actual field measur ements (Hoerger and Kenaga, 1972). Risk quotients are based on the most sensitive LC 50 

### and NOAEC for birds and LD 50 

### for mammals.

We derive terrestrial EECs for dinotefuran using the maximum proposed single and annual application rates ( i.e ., 2 applications of 0.131 lb a.i./acre ma de 7 days apart). The default 35-day foliar half-life value was used for modeling EECs on terrestrial food items. Table 9 illustrates expected terrestrial EECs for rice use.

### 14 Table 9. Estimated terrestrial exposure for us es of dinotefuran on rice using T-REX

Use Pattern Rice

Application Rate 0.131 lb a.i./A/application, two applications

Dietary-Based EECs (mg a.i./L) Short Grass:

Tall Grass: Broadleaf plants: Fruits, pods, seeds: Arthropods: 11.76 5.39 6.62 0.74 4.61



### ENVIRONMENTAL EFFECTS

Assessment of risk is based on the most sensiti ve species tested for terrestrial and aquatic organisms. The acute and chroni c toxicity values for the most sensitive aquatic animals and plants tested are presented in Table 10

, Table 11 , and Table 12 . The most sensitive terrestrial animal acute and chronic toxicity values are presented in Table 13 and Table 14 . These endpoints are based on those presented in the mo st recent assessment conducted for dinotefuran (USEPA 2012, D390191). The complete available eco toxicity dataset can be found within the USEPA 2012 assessment (D390191).

Aquatic Animals (Acute/Chronic) The data submitted by the registrant show that dinotefuran (technical MT I-446) is practically nontoxic on an acute basis to freshwater and estuarine/marine fish (96-hour LC 50 

### > 99 mg a.i./L) and saltwater mollusks (eastern oyster 96-hr EC 50 

### > 141 mg a.i./L; MRID 45639711); no sublethal effects were noted in these studies. The degradate of dinotefuran (DN phosphate) is also considered practically non-toxic to the freshwater invertebrate ( D. magna 48-hour LC 50 

### > 110.6 mg a.i./L; MRID 45639710); however, in the same acute study, on the basis of 10% immobility in the highest concentration test ed a NOAEC of 10 mg a.i./L was determined. However, on an chronic basis, dinotefuran appear s to be highly toxic to the estuarine/marine invertebrates (mysid shrimp LC 50 

### = 0.79 mg a.i./L; MRID 45639713).

Chronic toxicity testing on fr eshwater fish (rainbow trou t; MRID 45639719) and invertebrates ( D. magna ; MRID 45639718) showed no treatment rela ted effects and NOAECs of > 6.36 mg a.i./L and > 95.3 mg a.i./L, respectively. A chro nic toxicity test on the estuarine/marine invertebrate Americamysis bahia (MRID 48680006) indicates that dinotefuran is very highly toxic to estuarine/marine inve rtebrates on the basis of reprodu ctive and survival endpoints.

### 15 Table 10. Acute effect concentrations (LC 50 /EC 50 ) for aquatic animals following e xposure to dinotefuran and DN. Species Measurement Endpoint Time LC 50 /EC 50 MRID / OCSPP GLN# Rainbow Trout Oncorhynchus mykiss Mortality/Intoxication (TGAI: 97.26 %) 96hr (limit test) LC 50 > 99.5 mg a.i./L NOAEC ≥ 99.5 mg a.i./L Endpoint(s) affected: None. (Sub)lethal effects : None. 45639714 Acceptable /Practically nontoxic 1

Sheepshead minnow Cyprinodon variegatus Mortality/Intoxication (TGAI: 99.2 %) 96hr (limit test) LC 50 > 109 mg a.i./L NOAEC ≥ 109 mg a.i./L Endpoint(s) affected: None. (Sub)lethal effects : None. 45639717 Supplemental /Practically non-toxic 1

Waterflea Daphnia magna Mortality/Immobility (Test substance: DN phosphate, metabolite of dinotefuran) 48 hr LC 50 > 110.6 mg a.i./L NOEAC: 10 mg a.i./L LOAEC: 110.6 mg a.i./L

Endpoint(s) affected: After 48 hours, there was 10% immobility in the 110.6 mg a.i./L treatment group which was the basis for a NOAEC of 10 mg a.i./L. The control and other treatment groups had 0% immobility. 45639710 (Acceptable/Practically nontoxic 1 )

850.1010

Mysid Americamysis bahia Mortality (TGAI: 99.2%) 96 hr LC 50 : 0.79 mg a.i./L NOAEC: 0.49 mg a.i./L LOAEC: 1.0 mg a.i./L

Endpoint(s) affected: Mortality, sublethal effects

(Sub)lethal effects: At 96 hours, mortality was 5% in the control and 5, 5, 0, 5, 75, and 100% for the test concentrations, respectively. Erratic swimming and loss of equilibrium were observed in surviving mysids from the 1.0 and 2.0 mg a.i./L treatment levels during the test. Lethargic mysids were observed in the 1.0 mg a.i./L treatment level. 45639713 (Acceptable/ Highly toxic 1 )

850.1035

1 Based on EC 50 (mg/L): < 0.1 very highly toxic; 0.1-1 highly toxic; >1-10 moderately toxic; >10-100 slightly toxic; >100 practically nontoxic

### 16 Table 11 . Chronic effect concentrations (LC 50 /EC 50 ) for aquatic animals following exposure to dinotefuran Species Measurement Endpoint Time NOEL/LOEL MRID / OCSPP GLN# Rainbow Trout Oncorhynchus mykiss Endpoints considered: Fertilization / hatching success, time to hatch, timeto swim up, posthatch survival, terminal length, wet or dry weights Early life stage (94 days) (limit test) 94-d NOAEC > 6.36 mg a.i./L 94-d LOAEC ≥ 6.36 mg a.i./L Endpoint(s) affected: None. (Sub)lethal effects : None. 45639719 Acceptable 1

Waterflea Daphnia magna Endpoints considered: Mortality, reproductive effects (number of offspring per surviving adult), terminal length. 21-day chronic toxicity LC 50 /EC 50 > 95.3 mg a.i./L NOAEC > 95.3 mg a.i./L LOAEC ≥ 95.3 mg a.i./L Endpoint(s) affected: None. (Sub)lethal effects : None. 45639718 Acceptable 1

Mysid Americamysis bahia F0 Dry Weight, Length and Mortality;

Number of Live Offspring;

Time to first brood; 35 days F0 Female Dry Weight: NOEL = <0.044 mg a.i./L LOEL = 0.044 mg a.i./L

F0 Male Length: NOEL = <0.044 mg a.i./L LOEL = 0.044 mg a.i./L

F0 Mortality (Post Pairing 2 ): NOEL = 0.044 mg a.i./L LOEL = 0.089 mg a.i./L

Number of Live Offspring: NOEL = 0.089 mg a.i./L LOEL = 0.21 mg a.i./L

Time to First Brood: NOEL = 0.21 mg a.i./L 48680006 (Acceptable/ Very highly toxic 1 )

850.1350

1 Based on EC 50 (mg/L): < 0.1 very highly toxic; 0.1-1 highly toxic; >1-10 moderately toxic; >10-100 slightly toxic; >100 practically nontoxic

2 Based on the number of F0 organisms that were kept for the reproduction phase of the study.



### Aquatic Plants Toxicity testing on aqua tic vascular plants ( L. gibba ; MRID 45639731) showed no treatment related effects yielding 7-day EC 50 

### and NOAEC values of > 110 mg a.i./L and ≥ 110 mg a.i./L, respectively. Non- vascular plant ( P. subcapitata ) acute toxicity testi ng on two degradates MNG (MRID 45639733) and DN (DN-phospha te; MRID 45639734) also showed no treatment related effects and thus 96-hour EC 50 

### and NOAEC values of > 98.7/ ≥ 98.7 mg a.i./L and > 100.4 / ≥ 100.4 mg a.i./L, respectively. However, testi ng with the TGAI (MTI-446, dinotefuran) indicated a significant e ffect on cell density for P. subcapitata at the two highest test concentrations yielding a 96-hour NOAEC of 25 mg a.i./L; the EC 50 

### for cell density, biomass, and growth rate endpoints, however, is >97.6 mg a.i./L (the highest concentration tested).

### 17 Table 12 . Effect concentrations (EC 50 /NOAEC) for aquatic plants following exposure to dinotefuran and some of its metabolites Species Measurement Endpoint Time EC 50 /NOAEC MRID / OCSPP GLN# Vascular
Duckweed Lemna gibba Dry weight, growth rate, biomass (TGAI: 99.2 7- day All endpoints: EC 50 >110 mg a.i./L NOAEC =110 mg a.i./L Endpoints affected: None

(Sub)lethal effects: Compared to the control, frond dry wt decreased by 21.5, 2.9, 12.9, 2.3, and 4.3%, biomass decreased by 11.2, 3, 17.5, 12.5, and 8.4%, growth rate decreased by 4.8, 2.3, 6.9, 4.7, and 3.2%. 45639731 (Supplemental 1 )

850.4400

Non-vascular Green Algae Pseudokirchneriella subcapitata (a.k.a . Selenastrum capricornutum ) Cell density, biomass, growth rate (TGAI: 97.26%) 96 hr EC 50 > 97.6 mg a.i./L EC 05 : 21 mg a.i./L NOAEC: 25 mg a.i./L Endpoint(s) affected: Cell density.

(Sub)lethal effects: Cell density significantly reduced in the two highest test concentrations, thus the determination of NOAEC of 25 mg a.i./L. The 96-hr %inhibition of growth rate was 1.5, 0, 0.5, 1.6, and 2.0%; of AUG curve was 12, -3.2, -1.1, 5.9, and 3.6% for test concentrations, respectively. Shape of cells was unaffected. 45639732 (Acceptable)

850.5400

Green Algae Pseudokirchneriella subcapitata (a.k.a . Selenastrum capricornutum ) Metabolite MNG 96 hr EC 50 > 98.7 mg a.i./L NOAEC = 98.7 mg a.i./L Endpoints affected: None.

(Sub)lethal effects: Compared to the control, 96-hr %inhibition for cell density was 34, -8, and 23%, for growth rate was 20, -1.7, and 8.3%, for biomass was 30, - 9.8, and 14% 45639733 (Supplemental 2 )

850.5400

Green Algae Pseudokirchneriella subcapitata (a.k.a . Selenastrum capricornutum ) Metabolite DN (DN-Phosphate) 96 hr EC 50 > 100.4 mg a.i./L NOAEC =100.4 mg a.i./L Endpoints affected: None.

(Sub)lethal effects: Compared to the control, 96-hr %inhibition for cell density was 31, -6, and 1%, for growth rate was 7, 0, and 2%, for biomass was 15, 2, and 4% 45639734 (Supplemental 2 )

850.5400

1 The study is scientifically sound, but does not satisfy guideline requirements for a tier II acute toxicity study with aquatic vascular plants because there were an insufficient number of plants per replicate, test concentrations were not analytically determined, and replicate data were only provided for frond number.

2 As there is no study guideline for testing with a de gradate, the study is classified as supplemental.

### 18 Terrestrial Toxicity Summary (Acute/Chronic)

Birds Dinotefuran was tested on various species of birds (Japanese qua il, northern bobwhite quail, and mallard duck for acute oral and dietary studies ; and, bobwhite quail and ma llard duck for chronic reproduction studies). The parent compound is practically nontoxic to Japanese quail (LD 50 

### > 2,000 mg a.i./kg-bw; MRID 45639720) and bobwhite quail (LD 50 

### > 2,250 mg a.i./kg-bw; MRID 47353601) on an acute oral basis and to mallard duck (LC 50 

### > 5,000 mg a.i./kg-diet; whereby the mean test item intake 13 

### is 997.9 mg a.i./kg-diet per da y; MRID 45639722) and Japanese quail (LC 50 

### > 5,000 mg a.i./kg-diet; whereby the mean test item intake is 1301 mg a.i./kg-diet per day; MRID 45639721) on a subacute dietary basis. Howeve r, sublethal effects (lethargy up to 3 hours after administration of the test compound) were observed in the highest test concentration (2,000 mg a.i./kg-bw) of the acute oral Japanese quail study leading to a NOAEL determination of 1,000 mg a.i./kg-bw. Sublethal effects were not not ed in the bobwhite quail acute oral, mallard duck or Japanese quail acute dietary studies. Although there a ppeared to be no significant treatment-related effects on bobwhite quail (MRID 45639724) reproductive parameters, chronic testing on mallard duck (NOAEC = 2,150 mg a.i. /kg-diet; MRID 45639723) showed significant reductions in the percentages of number of ha tchlings/eggs laid, eggs set, and 14-day old survivors.

Mammals Dinotefuran is slightly to practically nontoxic on an acute oral (female LD 50 

### = 2000 mg/kg-bw; MRID 45639823) or acute inhalation (LC 50 

### > 0.71 mg a.i./L; MRID 47814506) basis to mammals (laboratory rat). Chroni c studies indicated effects on rats and rabbits. A 2-generation reproduction study for MTI-446 (dinotefuran) tec hnical on the rat indicated a reproductive NOAEL of 3,000 mg/kg-diet (M RID 45639913) based on decreased uterine weights and microscopic alterations in the ut erus and estrous cyclicity in F o 

### and F 1 

### females, slight increases in abnormal sperm morphology in F o 

### and F 1 

### males, and slight decreases in testicular sperm count in F o 

### males and sperm mortality in F 1 

### males. The developmental toxicity NOAEL for MTI-446 (dinotefuran) technical on rabbits is ≥ 300 mg/kg-bw/day, while the maternal toxicity NOAEL is 52 mg/kg-bw/day based on decreased body weight gain, decreased food consumption, and gross necropsy findings (pale discolorat ion of the liver and gray white plaques in the stomach). The rabbit study is included here to represent the most sensitive NOAEL and to illustrate that sublethal effects as a result of chronic exposur e to dinotefuran occur in multiple mammalian species. The degradates MNG and DN we re not tested on birds or mammals.

Terrestrial Invertebrates Dinotefuran technical, MTI-446, (M RID 45639725) is highly toxic to bees on an acute contact basis (48-hr LD 50 

### = 0.047  g a.i./bee) and on an acute oral basis (48-hr LD 50 

### = 0.023  g a.i./bee). Similarly, the dinotefuran fo rmulation, MTI-446 20%WG (MRID 45639726, with control; MRID 45639727, without negative but with solvent control) is also highly toxic to bees

on an acute contact (48-hr LD 50 

### = 0.061  g a.i./bee and 0.024  g a.i./bee, respectively) and on an acute oral basis (48-hour LD 50 

### = 0.032  g a.i./bee and 0.0076  g a.i./bee, respectively). The

13 The test item intake (TII) was calculated based on food consumption and the nominal test item concentration in the diet. For the dietary studies, these va lues were calculated by the study author.

### 19 RT 25 

### (residual time to cause 25% mortality) deri ved from the exposure to residues on alfalfa study (MRID 45639728) with the formulation MTI-446 20% WG indicated that bees were most sensitive to the 8 hour aged residue (RT 25 

### = 4.8 hours) and least sens itive to treatment when exposed to 48 hour aged residue (RT 25 

### = 90 hours). When translocated from pollen and nectar to bee hives, residues of dinotefuran can be detected in stored honey inside hives at least 85 days after application (hon eybee field study, MRID 48120501), wh ich suggests the occurrence of long-term chronic exposure inside the hive and has potential concerns for overwintering success.

In addition, exposure to dinotef uran formulation MTI-446 20% SG applications (of varying exposure periods) led to survivorsh ip and reproductive effects on non- Apis terrestrial invertebrates includi ng parasitoid wasp ( Aphidius rhopalosiphi , MRID 45640121), predaceous bug ( Orius laevigatus, MRID 45640122), and predatory mite (an arachnid, Typhlodromus pyri

, MRID 45640120) indicating LC 50 

### values of 6.89x10 -5 

### lb a.i./A, 1.19x10 -5 

### lb a.i./A, and 0.027 lb a.i./A, respectively. It is important to note that with the lowest non-definitive chronic endpoint NOAEC (<1.21 x 10 -6 

### lb a.i./A) reported for the predaceous bug study, it is unknown as to how much lower the application would need to be to elicit no response in terrestrial invertebrates. For additional comparative analyses including a comparison of dinotefuran and imidacloprid toxicities to insects refer to USDA Forest Service risk assessment (Durkin 2009; MRID 47814402). For further details on the toxicity studies see the USEPA 2012 assessment (D390191)

.

Table 13 . Acute effect concentrations (LD 50 /LC 50 ) for terrestrial organisms following exposure to dinotefuran. Species Measurement Endpoint Time LD 50 /LC 50 MRID / OCSPP GLN# Birds Japanese quail Coturnix japonica Oral Toxicity (TGAI: 97.26%) 14 day LD 50 > 2000 mg a.i./kg-bw NOAEL: 1000 mg a.i./kg-bw

No mortality observed. All ♂ & ♀ birds showed somnolence up to 3 hours after gavage in 2000 mg a.i./kg-bw level which was the basis for a NOAEL of 1000 mg a.i./kg-bw; otherwise, none 45639720 (Supplemental/Practically nontoxic 3 )

850.2100

Mammals
Rat Rattus norvegicus Oral Toxicity 14 day ♂ LD 50 = 2,804 mg/kg-bw ♀ LD 50 = 2,000 mg/kg-bw

Endpoint(s) affected: Morbidity. 45639823 (Acceptable/

Toxicity category III)

870.1100

Rat Acute Inhalation Toxicity (TEP: Dinotefuran 35SL; 35.3%) Limit test 4 hours (exposure) 14 day (observation) LC 50 > 2.02 mg form/L LC 50 > 0.71 mg a.i./L

(Sub)lethal effects: None. 47814506 (Acceptable /

Toxicity category IV)

870.1300
Invertebrates Honey bee Apis mellifera Acute Oral (EUP, MTI-446 48 hour LD 50 = 0.0076 μ g a.i./bee 45639727 (Supplemental 2 ;

### 20 Table 13 . Acute effect concentrations (LD 50 /LC 50 ) for terrestrial organisms following exposure to dinotefuran. Species Measurement Endpoint Time LD 50 /LC 50 MRID / OCSPP GLN# 20% WG: 21.4%) Endpoint(s) affected: Mortality.

(Sub)lethal effects: By 48 hours, 13, 3, 17, 43, 97, and 90% mortality was observed in the test treatments, respectively. Solvent control mortality was 20%. However, a concurrent dimethoate test had 13% mortality in the solvent control. At 4 hours, there were stumbling and/or knockdown bees observed in every treatment and control group, except for the 0.00056 μg a.i./bee

*An important note is that the control mortality exceeded 10% (an OECD requirement), but not the 20% guideline limit set for an acute contact study). highly toxic 1 )

850.3020

Honey bee Apis mellifera Acute Contact (EUP, MTI-446 20% WG: 21.4%) 48 hour LD 50 = 0.024 μ g a.i./bee

Endpoint(s) affected: Mortality.

(Sub)lethal effects: By 48 hours, 3, 3, 7, 43, 63, and 87% mortality was observed in the test treatments, respectively. Solvent control mortality was 0%. At 4 hours, there were stumbling and knockdown bees in the 0.036 and 0.08 μg a.i./bee groups. 45639727 (Acceptable / Highly toxic 1 )

850.3020

Parasitoid wasp 4 Aphidius rhopalosiphi (Hymenoptera, Braconidae) (EUP: MTI-446 20% SG) 13-day, survival ( exposure phase: 2 day exposure; 11 day obs) and separate repro study ( fecundity phase: 1 day exposure; 10 day obs) 13-d LC 50 : 77.2 mg a.i./ha (6.89x10 -5 lbs a.i./A) (95% CI: 59.4 – 102.6 mg a.i./ha; 5.30 x 10 -5 – 9.16x10 -5 lbs a.i./A)

NOAEC: 7 mg a.i./ha (6.25x10 -6 lbs a.i./A)

Endpoints considered: Mortality and reproductive effects (parasitism)

Endpoint(s) affected: Mortality, parasitism success.

(Sub)lethal effects: Corrected mortality (using Schneider-Orelli’s fomula 5 ) was -7, -2, 9, 50, and 74% in the test treatments, respectively. Significant mortality obs in the two highest concentrations. Negative control mortality was 10%. 45640121 Supplemental 2

### 21 Table 13 . Acute effect concentrations (LD 50 /LC 50 ) for terrestrial organisms following exposure to dinotefuran. Species Measurement Endpoint Time LD 50 /LC 50 MRID / OCSPP GLN# Percent reduction in parasitism success (#of aphid mummies per ♀ ) was -1 and 67% for the two concentrations tested (7 and 20 mg a.i./ha). Significant reduction in parasitism obs in 20 mg a.i./ha group. Control parasitization success was 8.4 aphid mummies per ♀ per 22 hour parasitization period.

Predaceous bug 4 Orius laevigatus (Hemiptera, Anthocoridae) (EUP: MTI-446 20% SG) 21 day (9 day exposure; 12 day obs), survival (9 days) and reproduction (12 days) study 21-d LC 50 : 13.3 mg a.i./ha (1.19x10 -5 lbs a.i./A) (95% CI: 7.0 - 25.1 mg a.i./ha; 6.25x10 -6 – 2.24x10 -5 lbs a.i./A)

NOAEC <1.36 mg a.i./ha (1.21x10 -6 lbs a.i./A) Probit slope: 2.11 LOAEC: 8.8 mg a.i./ha

Endpoints considered: Mortality and reproductive effects (oviposition, egg hatch success)

Endpoint(s) affected: Mortality.

(Sub)lethal effects: Corrected mortality (using Schneider-Orelli’s fomula 5 ) was 15, 1, 13, 43, and 49% in the test treatments, respectively. Significant mortality obs in the lowest and two highest concentrations. Negative control mortality was 16%.

Percent reduction in mean #of eggs produced per day per ♀ was 4 and -2% and percent inhibition for egg hatch were 0 and -1% for the two concentrations tested (2.72 and 5 mg a.i./ha). Fecundity was not significantly affected by treatment. Reproductive success was 6.9 eggs per ♀ per day and average egg hatch success was 92%. 45640122 Supplemental 2

### 22 Table 13 . Acute effect concentrations (LD 50 /LC 50 ) for terrestrial organisms following exposure to dinotefuran. Species Measurement Endpoint Time LD 50 /LC 50 MRID / OCSPP GLN# Predaceous mite 4 Typhlodromus pyri (Acari: Phytoseiidae) (EUP: MTI-446 20% SG) 14 day (7 day exposure; 7 day obs), survival (7 days) and reproduction (7 days) study 14-d LC 50 : 30.1 g a.i./ha (0.027 lbs a.i./A) (95% CI: 26.7- 34.2 g a.i./ha; 0.024 – 0.030 lbs a.i./A)

NOAEC <15 g a.i./ha (0.013 lbs a.i./A)

Endpoints considered: Mortality and reproductive effects (# of eggs and oviposition)

Endpoint(s) affected: Mortality, fecundity.

(Sub)lethal effects: Corrected mortality (using Schneider-Orelli’s fomula 5 ) was 39, 32, 79, 47, and 96% in the test treatments, respectively. Significant mortality obs in all test concentrations. Negative control mortality was 10%.

Percent reduction in mean #of eggs produced per day per ♀ was 41 and 51% for the two concentrations tested (15 and 20 g a.i./ha). Fecundity was significantly reduced in the 20 g a.i./ha treatment. Reproductive success was 9
eggs per ♀ per day. 45640120 Supplemental 2

1 Based on acute contact LD 50 ( μ g a.i./bee) <2 highly toxic; 2-10.99 moderately toxic; ≥ 11 practically non-toxic
2 The study is a non-guideline study and does not fulfill an OPP guideline requirement.
3 Acute Oral (avian/mammal): Based on LD 50 (mg/kg) <10 very highly toxic; 10-50 highly toxic; 51-500 moderately toxic; 501-2000 slightly toxic; >2000 practically nontoxic

4 The test species is not a US EPA-recomme nded species for toxicity testing with terre strial invertebrates; SEP guidelines do no t exist for this species.
5 Schneider-Orelli’s formula: Co rrected % = (%mortality in trea ted - %mortality in control) / (100-%mortality in control) *100

### 23 Table 14. Chronic effect concentrat ions (NOAEC/LOAEC) for terrestrial animals (birds/mammals) following exposure to dinotefuran Species Measurement Endpoint Time NOAEC/ LOAEC MRID / OCSPP GLN#
Birds Mallard duck Anas platyrhynchos 1-generation reproduction; dietary study (TGAI: 99.3%) 20 weeks NOAEC: 2150 mg a.i./kg-diet LOAEC: 5270 mg a.i./kg-diet

Endpoint(s) affected: number of hatchlings/eggs laid and set, 14-day old survivors/eggs set

(Sub)lethal effects: One incidental mortalityin control. Incidental injuries due to penwear. Reproductive effects resulted in endpoint determination. 45639723 (Acceptable)

850.2300

Mammals Rat Rattus norvegicus 2-Generation Reproduction; dietary study (TGAI: 98.9%) Repro. NOAEL = 3,000 mg/kg-diet (241-269 mg/kg-bw/day ♂ ; 267-292.6 mg/kg-bw/day ♀ )

Repro. LOAEL = 10,000 mg/kg-diet (822.1-934.7 mg/kg-bw/day ♂ ; 907-1004.8 mg/kg-bw/day ♀ )

Endpoint(s) affected/S ublethal effects: Decreased uterine weights, microscopic alteration in uterus and vagina of F
o ♀ ; decreased numbers of primordial follicles in F 1 ♀ , altered estrous cyclicity in F
o ♀ ; slight increases in abnormal sperm morphology in F
o and F 1 ♂ , and slight decreases in testicular sperm count in F
o ♂ and sperm mortality in F 1 ♂

. 45639913 (definitive test)45639914 (rangefinding test) (Acceptable)

870.3800

Rabbit New Zealand white Prenatal development; gavage study (TGAI: 92.9%) Average weight of pregnant females across all doses: 3.485 kg (3485 g) Maternal NOAEL = 52 mg/kg-bw/day Maternal LOAEL = 125 mg/kg-bw/day

Endpoint(s) affected: None. No statistically significant effects on developmental endpoints

Sublethal effects : Maternal toxicity wasevident at doses of 125 and 300 mg/kgbw/day. Decreased bw gain (80% of controls) in ♀ in the 125 mg/kg-bw/day group at gestation days 6-18 and transient decrease in food consumption (84-90% of controls) after initiation (gestation days 6- 10). Other findings include: liver discoloration, stomach plaque, transient neurological signs 45654208 (definitive test) 45639911 (range finding test) 45639912 (range finding test) (Acceptable)

870.3700

### 24 Terrestrial Plants

Terrestrial plant testing (Tier I s eedling emergence OCSPP 850.4100, MRID 45639729, and vegetative vigor OCSPP 850.4150, MRID 45639730) on te n species indicated no effects as a result of a single application of LX1414-01 MTI- 446 20% SG (20% dinotefuran) Lot # 01i-6252 at a rate of 0.54 lb a.i./A. For some plants, c onsidered endpoints exhib ited reductions relative to the controls which were < 25% whic h indicates that further testing ( i.e. , Tier II) is not needed. The 14-day EC 25 

### and NOAEL for both studies were >0.54 lb a.i./A and 0.54 lb a.i./A, respectively.

RISK CHARACTERIZATION

Aquatic Organisms

The high solubility of Dinotefuran an d DN in water (39,830 mg/L and 619,400 mg/L respectively), moderate persistence in the water column and soil (t 1/2 

### = 76-79.3 days under aerobic aquatic conditions; t 1/2 

### = 15-100 days in aerobic and anaerobic soils) and high mobility (K oc 

### of 6-45) suggests that dino tefuran is expected to dissolve in the water column. Concentrations in pore water are assumed to be e quivalent to those in th e water column in the rice paddy, as well as in the receiving body ( i.e. , a moving stream or a stagnant pond). Based on the currently available aquatic ecotoxicity stud ies, the proposed dinotefuran use on rice exceeds the level of concern for estuarine/marine inve rtebrates on both an acu te and chronic exposure scenarios (see Table 15 ).

Table 15 . RQs for Aquatic Organisms Exposed to Dinotefuran from the Proposed New Use on Rice

Taxa EECs 1 (μg a.i./L) Acute Endpoint (LC 50 in μg a.i./L) Chronic Endpoint (NOAEC in μg a.i./L) Acute RQ 4 Chronic RQ 4

Animals Freshwater Fish

269 99100 6360 0.003 0.04

Freshwater Invertebrate 110600 3 10000 0.002 0.03

Estuarine/Marine Invertebrate 790 44 0.34 6.11

Plants

Taxa EECs 1 (μg a.i./L) Non-listed Species Endpoint (EC 50 in μg a.i./L) Listed Species Endpoint (NOAEC in μg a.i./L) Non-listed Species RQ 4 Listed Species RQ 4

Vascular Aquatic Plants 269 110000 3 110000 0.002 0.002

Non-vascular Aquatic Plants 97600 3 25000 0.003 0.01

### 25 1 Concentrations are based on Tier I Rice Model outputs

2 The available acute freshwater invertebrate toxicity da ta for dinotefuran (Daphnid only) provides only nondefinitive toxicity values for the LC 50, so this was used as an estimate for the LC 50 .

. 3 The available aquatic plant toxicity data provides only non-definitive LC 50 endpoints, so these were used as an estimate for the LC 50 . 4 Values in bold are LOC exceedances (LOC: 0.05, acute listed speci es; 0.1, acute restricted use; 0.5 acute; 1, chronic).



### Terrestrial Animals

Risk quotients (RQs) were calculated based on mammalian and avian toxicity endpoints in Table 13 and EECs presented in Table 9 . The values calculated in Appendix A reflect upper bound Kenaga values. No exceedances of the Agency’s Levels of Concern (LOCs) were observed for either acute or chronic risk to terrestrial animals for any of the proposed new uses.

Based on the available invertebrate toxicity data, dinotefuran is very highly toxic to terrestrial insects and invertebrates. These organisms may be impacted from the proposed of the dinotefuran new use on rice, however because the proposed dinotefuran application timing would be post flowering, pollinator ( e.g . pollen harvesting insects) e xposures in the field should be minimized. Invertebrates resident in the fiel d or visiting the field fo r food, shelter, resting etcetera would be considered at risk. There is also a potential for off-site exposure from spray drift to pose a concern for terrestrial insect s and invertebrates from spray drift.

Terrestrial Plants

The available terrestrial plant toxi city data show little to no toxici ty of dinotefuran to plants (14- day EC 25 

### and NOAEL for both vegetative vigor and s eedling emergence studies were >0.54 lbs a.i./A). Based on the proposed single applicati on rate and the annual maximum a.i./A (0.131 lbs a.i./A and 0.262 lbs a.i./A respect ively), exceedances of the Agency ’s Levels of Concern (LOCs) for listed or non-listed plants are not e xpected for the proposed new rice use.

Endangered Species

Since dinotefuran is toxic to honeybe es, it is assumed that it may also be toxic to listed terrestrial invertebrates (those that are fede rally listed as endangered or th reatened). In addition, should invertebrate prey populations dec line to a point where they woul d negatively impact predator populations, then dinotefuran applications could have indirect effects on various insectivorous taxa including mammals and birds, or plants that are pollinated by invertebrates. In other words, any listed species that relies on te rrestrial invertebrates during its li fe-cycle may potentially be at risk.

Incidents

Data on ecological incidents can be obtained through three incident databases: 1) the Ecological Incident Information System v. 2.1.1 (EIIS) ma intained by EFED; 2) the Avian Incident Monitoring System (AIMS) maintained by the Amer ican Bird Conservancy; and, 3) the Incident Data System (IDS), a component of the PRISM database maintained by ITRMD.

### 26 No incidents have been reported ( i.e., no records were found) in which dinotefuran has been associated with some type of environmental effect; this is the case for all three incident databases searched, which were last run for the recent problem formulation for Registration Review (D389547, December 13, 2011). The absence of documented incidents does not necessarily mean that such incidents did not occur.

II. Summary

With the exception of concerns for ri sks to terrestrial invertebrates ( e.g., pollinators), there are generally no risks of concern for exposures to terrestrial organism s or plants. However, based on the proposed rice use, EPA’s level of concern is exceeded for listed aquatic estuarine/marine invertebrates. These concerns for aquatic invertebrates are pr imarily focused on the production areas of the Gulf of Mexico region due to their proximity to the estuarine and marine environment and water management practices in this region.

### 27 Appendix A. T-REX Mo del Inputs/Results

Table A-1. Upper Bound Kenaga, Acute Avian Dose-Based Risk Quotients

Size Class (grams) Adjusted LD50 EECs and RQs

Short Grass Tall Grass Broadleaf Plants Fruits/Pods/Seeds Arthropods Granivore

EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ

20 1440.86 13.40 0.01 6.14 0.00 7.54 0.01 0.84 0.00 5.25 0.00 0.19 0.00

100 1834.29 7.64 0.00 3.50 0.00 4.30 0.00 0.48 0.00 2.99 0.00 0.11 0.00

1000 2591.00 3.42 0.00 1.57 0.00 1.92 0.00 0.21 0.00 1.34 0.00 0.05 0.00

Table A-2. Upper Bound Kenaga, Chroni c Avian Dietary Based Risk Quotients 1

NOAEC (ppm) EECs and RQs Short Grass Tall Grass Broadleaf Plants Fruits/Pods/Seeds Arthropods EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ

2150 11.76 0.01 5.39 0.00 6.62 0.00 0.74 0.00 4.61 0.00

1 An LC 50 could not be determined from the available dietary studies.

Table A-3. Upper Bound Kenaga, Acute Ma mmalian Dose-Based Risk Quotients

Size Class (grams) Adjusted LD50 EECs and RQs
Short Grass Tall Grass Broadleaf Plants Fruits/Pods/Seeds Arthropods Granivore

EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ

15 4395.66 11.21 0.00 5.14 0.00 6.31 0.00 0.70 0.00 4.39222 0.001 0.1558 4E-05

35 3556.56 7.75 0.00 3.55 0.00 4.36 0.00 0.48 0.00 3.03561 0.0009 0.1076 3E-05

1000 1538.32 1.80 0.00 0.82 0.00 1.01 0.00 0.11 0.00 0.70382 0.0005 0.025 2E-05

Table A-4. Upper Bound Kenaga, Chronic Mammalian Dietary Based Risk Quotients 1

NOAEC (ppm) EECs and RQs
Short Grass Tall Grass Broadleaf Plants Fruits/Pods/Seeds/Large Insects Arthropods

EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ

4820 11.76 0.00 5.39 0.00 6.62 0.00 0.74 0.00 4.61 0.00

1 An LC 50 could not be determined from the available dietary studies.

Table A-5. Upper Bound Kenaga, Chronic Mammalian Dose-Based Risk Quotients

Size Class (grams) Adjusted NOAEL EECs and RQs
Short Grass Tall Grass Broadleaf Plants Fruits/Pods/Seeds Arthropods Granivore
EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ

15 529.68 11.21 0.02 5.14 0.01 6.31 0.01 0.70 0.00 4.39 0.01 0.16 0.00

35 428.57 7.75 0.02 3.55 0.01 4.36 0.01 0.48 0.00 3.04 0.01 0.11 0.00

1000 185.37 1.80 0.01 0.82 0.00 1.01 0.01 0.11 0.00 0.70 0.00 0.02 0.00

DP Barcode Summary

### 28 DP Barcode Authors Title Date 285633 Dutta, S. and J.L. Ellis Revised Section 3 Environmental Risk Assessment for the Registration of Dinotefuran on Leafy Vegetable, Turfgrasses, Ornamentals and Residential Use. 06/30/04

D304957 Dutta, S. and J.L. Ellis FIFRA Section 3, Environmental Risk Assessment for the New Use Registration of Dinotefuran on Cotton, Potato, Head and stem Brassica, Fruiting Vegetables, Cucurbits, Grapes, Ornamental Plants and Flower Beds, Lawn, Shrubs and Additional Residential Uses. 08/09/04

324854 Patrick FIFRA Section 3, Environmental Risk Assessment for Increasing the Use Rates for the Registration of Dinotefuran on Head and Stem Brassica, Cucurbits, Fruiting Vegetables, Grapes , Leafy Vegetables, and Potatoes. 10/16/06

332829 Federoff, N.E. and F.A. Khan Section 18 Request for Use of Dinotefuran in Texas on Leafy Brassica to Control Whitefly. 10/31/06

355010 Meléndez, J. and N.E. Federoff Section 18 Request for Use of Dinotefuran in Texas on Rice to Control Rice Stink Bug. 10/28/08

358860 Meléndez, J. and A. Solliday Incremental Environmental Risk Assessment for IR-4 for the Registration of Dinotefuran Use on Leafy Brassica (Subgroup 5B) 06/15/09

378125 Crk, T. and R. Parker FIFRA Section 3 New Use, Environmental Risk Assessment for the Registration of Dinotefuran for Forestry Uses (Christmas Trees, Trees in Plantations, Reforestation Nurseries, Forests, and Woodland Areas) 05/03/11

388997+ Crk, T. and R. Parker Section 18 Request for Use of Dinotefuran in VA, WV, DE, MD, NC, PA, and NJ on Stone Fruit and Pome Fruit to Control Brown Marmorated Stink Bug 06/16/11

390191 Crk, T. and R. Parker FIFR A Section 3 New Uses (IR-4 Petition), Environmental Risk Assessmen t for the Registration of Dinotefuran for bulb and green onion subgroups (3- 07A&B), low growing berry (13-07H, except strawberry), small fruit and vine climbing (berry) subgroup (13-07F, except fuzzy kiwifruit), tuberous and corm vegetables subgroup (1C), watercress, and peach. 02/14/12

389547 Crk, T., R. Parker, J. Hetrick, D. Spatz Registration Review: Problem Formulation for Environmental Fate, Ecological Risk, Endangered Species, and Drinking Wate r Exposure Assessments for Dinotefuran 12/12/11

283465 Dutta, S. and J.L. Ellis EFED’s Data Evaluation Records for the Registration Action of the Proposed Use of Dinotefuran on Leafy Vegetable, Turf grasses, and Residential uses 05/13/04

290192 Dutta, S. Tier I Estimated Drinking Water Concentrations of Dinotefuran (MTI-446) and its major transformation products for use in Human Health Risk Assessment 01/21/04

304958 Dutta, S. Tier I Estimated Drinking Water Concentrations of Dinotefuran (MTI-446) and its major transformation products for use in Human Health Risk Assessment 06/07/04

324853 Meléndez, J.L. Tier I Estimated Drinking Water Concentrations of Dinotefuran (MTI-446) and Its Transformation Products of Concern for Use in Huma n Health Risk Assessment 09/18/06

324854 Meléndez, J.L. Tier I Estimated Drinking Water Concentrations of Dinotefuran (MTI-446) and Its Transformation Products 09/18/06

### 29 DP Barcode Summary DP Barcode Authors Title Date of Concern for Use in Huma n Health Risk Assessment 354339 Meléndez, J.L. Tier I Estimated Drinking Water Concentrations of Dinotefuran (MTI-446) and It’s Transformation Products of Concern MNG, DN, UF and DN-2-OH + DN-3-OH, for Use in Human Health Risk Assessment: Section 18 Emergency Exem ption for the Use of the Chemical on Rice in Texas 04/09/09

357111 Meléndez, J.L. Tier I Estimated Drinking Water Concentrations of Dinotefuran and its Transformation Products of Concern MNG, DN, UF and DN-2-OH + DN-3-OH, for Use in Human Health Risk Assessment, Proposed New (IR-4) Use of the Chemical on Leafy Brassica Greens and Turnip Greens 01/23/2009

378125 Parker, R. Dinotefuran Drinking Water Assessment for the Additional Registration of Forestry Uses 02/01/11

384148 Parker, R. Dinotefuran Drinking Water Assessment for the Additional Registration of Forestry Uses 02/03/11

394848 Parker, R. Tier I Human Health Drinking Water Assessment of Dinotefuran and its Transformation Products of Concern (MNG, DN, UF and DN-2-OH + DN-3-OH) in Support of Proposed IR-4 New Uses (Onion, Bulb and Green; Berry and Small Fruit; Tuberous and Corm Vegetables; Peach; and Watercress) 12/12/11

334846 Steeger, T. Review of Proposed Bee Study Protocol for Dinotefuran 03/09/07 397490 Wolf, J.K. Tier 1 Drinking Water Concentrations for Dinotefuran for Section 3 new use on Rice. 08/07/12