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

. 20460

MEMORANDUM OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION 

### PC Code: 030090 DP 

### Barcode: 417685 

### Date: 

### June 3rd, 2014



### SUBJECT: EFED Registration Review Problem Formulation for Pyraflufen-ethyl

FROM: Justin Housenger,

# B~ologist fJ/

# ~·**:~ OJ** **~** Mohammed Ruhman, Ph.D., Senior**Agronom~j!!_t~Jf!!~~~:::::--~7.~-** 

### Environmental Risk Branch 5

. 

# Ot**jo~f** 

# Jt Environmental Fate and Effects Division (7507P)
TO: Steven Snyderman, Chemical Review Manager Tracy Perry, Risk Manager Risk Management and Implementation Branch 3 Pesticide Re-Evaluation Division (7508P)
REVIEWED Hannah Yingling, Biologist BY: Michael Barrett, Senior Chemist Environmental Risk Branch 5 Environmental Fate and Effects Division (7507P)

THROUGH: Mah Shamim, Branch Chief Environmental Risk Branch 5 Environmental Fate and Effects Division (7507P)

1

### 2 

## Table of Contents 1. Executive summary

................................ ................................ ................................ ................. 3 2. Introduction

................................ ................................ ................................ ............................. 5 3. Use Characterization

................................ ................................ ................................ ............... 6 4. Conclusions from Previous Risk Assessments

................................ ................................ ....... 8 5. Environmental Fate and Transport

................................ ................................ ........................ 11 6. Receptors

................................ ................................ ................................ ............................... 17 7. Exposure Pathways of Concern

................................ ................................ ............................ 25 8. Analysis Plan

................................ ................................ ................................ ........................ 27 9. Endangered Species Assessments

................................ ................................ ......................... 29 10. Endocrine Disruptor Screening Program

................................ ................................ ........... 29 11. Preliminary Identification of Data Gaps

................................ ................................ ............ 29 12. References

................................ ................................ ................................ .......................... 34

### 3



# 1. Executive summary

The Environmental Fate and Eff ects Division (EFED) have completed the attached preliminary problem formulation for the ecological risk, environmental fate, endangered species, and drinking water assessments to be conducted as part of the registration review pyraflufen

- ethyl. The probl em formulation describes the methods planned to be used during the completion of drinking water and ecological risk assessments in support of registration review and provides an overview of the environmental fate, ecological effects, and potential risks as sociated with the use of pyraflufen

- ethyl as well as uncertainties unique to risk assessment of pyraflufen

- ethyl. This document also identifies additional studies that may be included in a data call

- in (DCI) to address uncertainties surrounding the enviro nmental fate and potential ecological effects. Although p yraflufen

- ethyl is relatively insoluble in water , the low application rate makes the amount applied readily soluble. The major degradates of the chemical are much more soluble which makes it readi ly available for leaching. Pyraflufen

- ethyl is not likely to volatilize significantly from wet or dry surfaces ( very low vapor pressure and Henry’s Law Constant ) . The octanol/water partition coefficients (K OWs 

### ) of pyraflufen

- ethyl and its degradate E

- 3 ar e relatively high suggesting possible bio

- concentration in aquatic organisms such as fish. In contrast, the other two major transformation products (E

- 1 and E

- 2) show much lower octanol/water partition coefficient suggesting low tendency to bio

- concentrate . Pyraflufen

- ethyl shows a high potential to hydrolyze under alkaline conditions. The major transformation product is E

- 1, which resists further hydrolysis at all pH levels tested. Pyraflufen

- ethyl also undergoes photolysis quickly in water and on soil ( half

- lives of about 2.5 and 2 days, respectively). The major transformation products were PD

- 1 (not found in other fate studies) and E

- 1 in water and on loamy sand , respectively

. Please see Appendix 2 for more information on the chemical names and struct ures for each degradate. Based on laboratory and field studies, parent pyraflufen

- ethyl was found to be short

- lived in aerobic and aquatic systems (half

- lives <2 days and in hours, respectively ). The major transformation pathways are hydrolysis, photol ysis and metabolism forming transformation products E

- 1, E

- 2 and E

- 3. The E

- 1 and E

- 2 transformation products show different persistence patterns in different soils/aquatic systems depending on soil type, temperature and aerobicity (refer to S ection 5 ) bu t E

- 3, which is the terminal degradate, is expected to be highly persistent in the environment. A notable exception to this degradation pattern was the aqueous photolysis dissipation pathway , where PD

- 1 was a major transformation product although PD

- 1 di d not appear to be persistent under photolytic conditions. For pyraflufen

- ethyl, E

- 1, E

- 2, and E

- 3, mobility was classified as slightly mobile, moderately mobile to mobile, slightly mobile, and slightly mobile, respectively (FAO, http://www.fao.org/docrep/003/x2570e/x2570e06.htm )

. Terrestrial field dissipation studies conducted in CA and WA confirm that the major transformation products found in the field are E

- 1 and E

- 3. They were not pres ent at significant amo unts below the 6

- inch level. Due to the fact that parent is short

- lived in the soil it is not expected to be leached and/or transported into aquatic systems by run

- off.

### 4

The combined p arent pyraflufen

- ethyl and degradates E1, E

- 2 and E

- 3 are considered to be the main stressor in this risk assessment for both drinking and surface waters noting that short

- term exposure will be mainly associated with E

- 1 because parent is expected to degrade rather quickly (half

- life <1 day) . In contrast, chronic or long

- term exposure is expected to be, in most cases, associate with E

- 3 as it is the most persistent degradate ( the terminal degradate )

. A different approach may be used, by calculating exposure EECs for individual species in the stressor depen ding on toxicity data that may be submitted by the registrant and how it compares to parent toxicity.
The main driver of potential risk for pyraflufen

- ethyl is terrestrial and aquatic plants (which is anticipated for a chemical with a known herbicidal mo de of action). Parent p yraflufen

- ethyl did not cause mortality in acute aquatic toxicity studies (fish and invertebrates) at concentrations up to and including the solubility limit (82 μg a.i/L). Definitive endpoints were established in chronic aquatic t oxicity studies but previous assessments show that parent pyraflufen

- ethyl degrades to the degradate E

- 1 in 1

- 2 days. Available toxicity data for E

- 1 (acute and chronic) shows that E

- 1 is 2

- 3 orders of magnitude less toxic than parent pyraflufen

- ethyl (de pending on the taxa). There is currently no ecotoxicity data available for E

- 2 and E

- 3. For terrestrial organisms, pyraflufen

- ethyl caused no treatment related mortality in one acute oral and two sub

- acute dietary studies that are available. The acute o ral and sub

- acute dietary studies tested up to concentrations of 2000 mg a.i/kg

- bw and 4836 mg a.i/kg

- diet, respectively. While two chronic avian reproduction studies were submitted, one was determined to be unacceptable due to several deviations which in cluded instability of the test substance in the treated feed, onset of egg laying during the test, and humidity and temperature conditions of the adult birds and stored eggs. In another study determined to be suitable for quantitative risk assessment, the re were no effects observed up to and including the highest treatment concentration (500 mg a.i/kg

diet). Available acute and chronic toxicity data for mammals indicate no mortalities or treatment related effect on any reproductive parameter.
There are a couple of sources of uncertainty for the ecological risk assessment f or pyraflufen

ethyl :

- Lack of E
- 2, E
- 3 data, ECOSAR estimates: As stated previously, parent pyraflufen

- ethyl is expected to undergo degradation to E

- 1 within 1

- 2 days, and subsequently transforms to E

- 2 and then to E

- 3. Currently, there are toxicity data available only for E

- 1, that indicate the degradate is 2

- 3 orders of magnitude less toxic than pyraflufen

- ethyl. As no data are available for E

- 2 and E

- 3, the quantitative structure a ctivity relationship (QSAR) tool ECOSAR was used to estimate toxicity to various taxa ( Section 6 )

. While the estimates are subject to uncertainty based on the lack of data points that inform the estimates, the analysis showed that E

- 2 and E

- 3 are generall y more toxic than E

- 1 but still less toxic than parent pyraflufen

- ethyl. Additionally, application rates of parent pyraflufen

- ethyl are quite low (maximum seasonal rate on currently registered labels is 0.018 lbs a./A). The degradate E

- 3 can reach aquati c systems either by drift (maximum percentage expected to be 10%) or by run
- off in soils where E

- 3 formation can be up to 50% of the applied pyraflufen

- ethyl application rate. Therefore, while it is an uncertainty on the toxicity of E

- 2 and E

- 3 without re gistrant

### 5

submitted toxicity data, the contribution to ecological risk posed by these degradates is expected to be low.

- To xicity of ET
- 751 2.5% formulation:
While available acute aquatic toxicity data indicate that pyraflufen

- ethyl TGAI did not cause mort alities up to and including the solubility limit, there are three acute toxicity studies conducted with formulated pyraflufen ethyl (as ET

- 751 2.5%) that did show mortality effects. There are two studies available for freshwater fish , and one study for fr eshwater invertebrates

. In one study with the bluegill sunfish, formulated pyraflufen ethyl was tested at concentrations up to 6.3 mg a.i/L (mean measured). There was 100% mortality observed in the top two concentrations with the first 24 hours. Total mo rtality occurred at the third highest treatment concentration by test termination and by 48 hours in the formulation blank. In a second freshwater fish study with the rainbow trout, 100% mortality occurred in the top treatment concentration (mean measured 3.5 mg a.i/L) and 95% in the second highest concentration by test termination. Additionally, 95% mortality occurred in the formulation blank by test termination. Finally, in a freshwater invertebrate toxicity study with formulated product, percent immob ilization was observed to be 70 and 80% for the 1.8 and 3.0 mg a.i/L mean measured concentration (top two concentrations). There was also 55% immobilization in the formulation blank. This data indicate that a component of the formulation ET

- 751 2.5% is h ighly toxic on an acute exposure basis to freshwater fish and invertebrates based on significant mortality effects in the formulation blank group. It is not known at present the extent of use of this formulation as its use would be expected to impact aqua tic systems to a greater extent than TGAI pyraflufen

- ethyl. It was determined that there are no major data needs for ecological effects. At this time no major need for environmental fate data. However, a clarification is needed on the environmental che mistry methods (ECMs) and associated independent laboratory validations (ILVs). Needed clarification is noted in Table 11, below.


# 2. Introduction
For this Problem Formulation (PF), EFED evaluated the most recent ecological risk assessments for pyraflufen

- et hyl association with any updated toxicity, exposure, and use and usage information to determine if sufficient data are available and if further updates are needed to support registration review. Pyraflufen

- methyl was registered on September, 27, 2002 with an ecological risk assessment conducted for Section 3 registration on Corn (grain, stover and forage); Cotton; Potatoes; and Soybeans (grain, hay and forage) 1 

### . The registration was followed, in 2008, 2011 and 2012; by new use registrations on many other u se patterns (refer to use characterization section for these use patterns). It is noted that the ecological risk assessment conducted in 2002 was used to support the new use registrations of 2008, 2011 and 2012. EFED considered this referenced assessment in addition to the latest Agency science policies and risk assessment

1 EFED Section 3 Registration Chapter for Py raflufen

- Ethyl ( DP Barcodes: D283754, D279383, and D278170; Dated August 2002)

### 6

methodologies. The structures of pyraflufen

- ethyl and major degradate as well as the chemical names and other identifiers can be found elsewhere in this document. Pyrafluf en
- ethyl is a contact herbicide and, according to the label, the product is rain

- fast (efficacious if no rain occurs). The chemical belongs to the phenyl pyrazole class of chemicals called protox inhibitors. Protox is also known as protoporphyrinogen oxidase whose inh ibition leads to the buildup of the compound protoporphyrin IX. This buildup causes protoporphyrin IX to move from the reaction center in the chloroplast into the cytoplasm where interactions with oxygen and light results in formation of oxygen free radic als that cause lipid peroxidation. This eventually causes plant death by disrupting the cell membrane. As the process is dependent on light, chemicals in this group of compounds inhibiting protox are called light

- dependent peroxidizing herbicide s (LDPH)

. This class of herbicide is known to have a photo

- toxic mode of action in plants and possibly in fish. LDPHs may be more toxic when exposed to natural sunlight, such as exposure conditions in the field. 

# 3. Use Characterization

Labeled Use Pyraflufen

- et hyl is herbicide with 17 active registrations including one Section 24(c)

– Special Local Needs (SLN) for Arizona and no pending new uses. The chemical is currently labeled for:

 Pre

- plant burn

- down, post

- emergence weed control in corn, pastureland, peanut s, rangeland and soybeans;

 Pre

- plant burn

- down, post

- emergence and layby weed control and as a defoliation agent in Cotton;

 Weed control in turf (turf area, golf courses and sod farms), crop areas (pre

- plant fallow beds and crop stubble) and non

- crop and uncultivated areas;

 Weed control in certain bearing & non

- bearing tree crops as dormant, pre

- bloom, in season, and postharvest applications in pome/stone fruits (CGs= Crop Groups 11/12), nut trees (CG 14), olives, pomegranates, hops, and vines “grapes” ;

 Crop desiccation in potatoes; and

 Pre

- plant burn

- down weed control in cereal grains (CG15), cole crops (CG5), cucurbits (CG9), fruiting veg. (CG8), leafy veg. (CG4), legumes (CG6), oil seed crops (CG20), root & tuber vegetables (CG1) and sugarcane Pyr aflufen

- ethyl is formulated in two products: 2% SC and 2.5% EC ET Herbicide/Defoliant. It can be applied by ground and/or aerial equipment depending on the use pattern. Recently, labeled uses were examined and a summary of the main uses/application parame ters were summarized and are presented in Appendix 1 . It is noted that EFED will use this referenced

### 7

data in future exposure modeling. Therefore, the registrant is requested to review data presented in Appendix 1 for accuracy and completeness noting that E FED exposure modeling is largely based on the following:

 The highest single application rate and the highest number of applications/crop/year to arrive at the maximum lbs a.i/A/year. The maximum annual rate allowed per acre not crop should be stated in th e label. This rate should take in consideration all a.i applied to one acre of land throughout the year

.

 The shortest application intervals (days);

 The type of application and equipment (foliar, soil, incorporation with stated depth, aerial, ground or ot her);

 Timing of the first application (should be clearly defined in the label); and

 Any other information and restrictions that should be considered in exposure modeling. Missing information will result in conservative assumptions in modeling exposure t hat will result in conservative risk estimation

. Usage Screening level of agricultural usage data for pyraflufen

- ethyl is summarized in Table 1 . This pesticide usage data is compiled by the Biological and Economic Analysis Division (BEAD) from various so urces for pyraflufen

- ethyl as a single active that is used on agricultural crops.
Table 1 Screening Level Usage An alysis (SLUA): Screening Level Estimates of Agricultural U ses of P yraflufen

- ethyl (2004

- 2011 reporting years; dated April 15, 2013)
Crop (s) Lbs a.i Used Percent Crop Treated

Average Maximum Cotton 2,000 5% 10% Tomatoes 10 10% 20% Peaches, Pistachios, Plums/Prunes, Each <500 <2.5% <2.5% Alfalfa, Almonds, Apples, Cherries, Corn, Dry beans/Peas, Fallow, Grapes, Onions, Pasture, Peanuts, Pe cans, Potatoes, Sorghum, Soybeans, Squash, Sunflower, Walnuts and Wheat, Each <500 <1% <2.5% Apricots*, Kiwi*, Nectarines*, Olives*, and Pomegranates*, Each <500 NC NC * Based on California department of pesticide regulations (CA DPR ) data only; noting t hat California represents >80% of the USA acreage for these crops; and NC= Not calculated; only pounds a.i are available.


### Data in Table 1 suggest that the highest usage was reported for cotton (mostly as defoliant) and tomatoes. Reported usage o n other c rops appears to limit to <500 lbs a.i/each crop with a maximum of <2.5% of the acres treated for crops other than cotton and tomatoes.

### 8

An overview of Pyraflufen

- ethyl and its use and usage information were prepared by the Biological and Economic Analysis Division (BEAD). This report is included in the docket (Screening Level Usage Analysis (SLUA) Date: April 15, 2013”)


# 4. Conclusions from Previous Risk Assessments
The ecological risk assessments that were conducted for pyraflufen

- ethyl were: (1) The 2002 Secti on 3 new chemical registration on Corn (grain, stover and forage); Cotton; Potatoes; and Soybeans (grain, hay and forage) 2 

### ; (2) The Section 3 new use r egistrations on:

a. Non

- crop areas; Nurseries, Ornamental plantings; and Pastures; and Ground Pre

- plant burn

d own for Vegetables “ Tuber & Root, Fruiting, and Cucurbits”, Cole crops, Legumes, and Small grains; Sod farms; and Christmas Trees in 2008 3 

### ; b. Aerial Pre

- plant burn

- down uses in 2009 4 

### ;

c. Tree Nuts, Stone Fruits, Pome Fruits, Hops, Grapes, Olives, and Pomegran ates in 2011 5 

### ; and
d. Hops and Peanuts in 2012 6



## a. Ecological Risk Assessment The ecological risk assessment conducted in 2002 ( EFED Section 3 Registration Chapter for Pyraflufen

- Ethyl; DP Barcodes: D283754, D279383, and D278170; Dated August 2002) was used to support the initial registration as well as the new use registrations of 2008, 2011 and 2012. This is because rates for the new uses were similar to uses in the initial registration. The 2002

2 EFED Section 3 Registration Chapter for Pyraflufen

- Ethyl ( DP Barcodes: D283754, D279383, and D278170; Dated August 2002)

3 EFED Registration for Pyraflufen

- ethyl to be used on Pastures, Wheat, Soybean, Corn, Pastures, Sod farms, Christmas Trees, Nurseries, Ornamental plantings and for Non

- Crop Weed Contro l. Also for Use as a Pre

- Plant Burn down on Root and Tuber Vegetables, Cole Crops, Legumes, Fruiting Vegetables, Cucurb its and Small Grains ( DP Barcodes: D337845, D342902, D343458, D343461 and D343914 ; Dated Jan, 2008)

4 EFED Registration of Pyraflufen

- ethyl for Aerial Pre

- Plant Burn down Uses (DP Barcodes: D364054 and D364057 ; dated August, 2009)

5 Section 3 New Use fo r Pyraflufen

- ethyl for the Uses on Tree Nuts, Stone Fruits, Pome Fruits, Hops, Grapes, Olives, and Pomegranates as the End Use Products ET ® 2% Herbicide/Defoliant and ET ® Herbicide/Defoliant (DP Barcodes: D377362, D377366; Dated 01/24/2011)

6 Section 3 Ne w Use for Pyraflufen

- ethyl for the Uses on Hops and Peanuts as the End Use Product ET ® 2% Herbicide/Defoliant and ET ® 2.5% Herbicide/Defoliant on Peanuts (DP Barcode: 397880; Dated 10/09/2012)

### 9

ecological risk assessment along with additional information presented in the 2008, 2011 and 2012 documents served as the basis for this scoping document covering pyraflufen

- ethyl. The risk assessment identified risk to endangered and non

- endangered terrestrial and aquatic plant species but predicted risk below the level of concern for other terrestrial and aquatic species tested. Other ecological risk conclusions are described below.

 It was in identified in the new chemical assessment (August 2002) that for dicot terrestrial plants adjacent to treatment areas and i n semi aquatic areas, risk quotients (RQs) exceeded the levels of concern (LOCs) for potatoes (ground application) and for cotton (aerial and ground applications). It was stated in this assessment that EFED is concerned about the toxicity of the formulati on used in the typical end use product (TEP). ET

- 751 2.5% EC contains a solvent in the formulation that is believed to be very toxic to aquatic organisms. The formulation produced mortality (26% on day 1 and 75% by day 14) and reductions in reproduction (# eggs and larvae per female) in a study using predacious mites. It appears that the formulation may pose similar toxicity and risk to honeybees. Furthermore, while the data set is limited, there are three acute toxicity studies available with this form ulation that indicate the ET

- 751 2.5% EC is in the range of a factor of 2.5 to 4 times more toxic than TGAI pyraflufen

- ethyl. There was no risk identified for other aquatic or terrestrial species for the proposed uses.

 All subsequent new use assessment s relied on the risk findings of the initial new chemical assessment as application rates were similar to those previously assessed.
Table 2
. Summary of Risk Concerns Identified for Pyraflufen

- ethyl in Previous Assessments
Birds Mammals Terr. Plants Terr.

I nverts Fish BCF Aquatic Inverts Aquatic

Plants Groundwater

Contamination Persistence Degrad at es of Concern No No Yes N/A No a No No a Yes No b No c E
- 1, E
- 2, E
3 a Studies with parent pyraflufen

- ethyl were tested up to solubility limit (82 μg/L) with no def initive LC 50 being established due to lack of mortality . However, in three acute toxicity studies with formulated pyraflufen

- ethyl (ET

571 2.5%), there w ere significant levels of mortality in multiple treatment concentrations as well as the formulation bl ank concentration. b Parent pyraflufen

- ethyl is not expected to leach due to non

- persistence, however its major degradates are expected to leach in variable amounts depending on persistence mobility that appear to change with soil type and temperature.

c P arent pyraflufen

- ethyl is expected to degrade rapidly in the soil and aquatic media to the transient degradates E

- 1 and E

- 2. Eventually E

- 2 degrades to E

- 3 which is shown by environmental fate data to be persistent. Yes = at least one LOC has been exceede d in previous assessments; “ No “ = LOCs have not been exceeded in previous assessments ; NA = RQs have not been calculated previously. 

## b. Drinking Water Exposure Assessments The first drinking water exposure assessment was conducted in 2002 based on estimated drinking water concentrations EDWCs for use on potatoe s (highest application rate ) 7



### . Tier 1 FIRST model was used for surface water and SCIGROW model for ground water. EDWCs for the

7 Tier I Estimated Environmental Concentrations of Pyraflufen for the Use in the Human Health Risk Assessment (DP Barcode: D274672; dated July 18, 2002). This is the DW assessment associated with the chemical first registration: Section 3 registration on Corn (grain, stover and forage); Cotton; Potatoes; and Soybeans (grain, hay and forage)

### 10

stressor (parent with E

- 1 , E

- 2, and E

- 3) w ere estimated to be 1.25 ppb fo r acute exposure (peak value) and 0.28 ppb for chronic exposure ( annual average value) . The groundwater screening concentration from SCIGROW was 0.002 ppb for acute/chronic exposures

. The same EDWCs were used as exposure estimated for new use assessments c onducted later in 2009 and 2008 8



### . In this assessment, two modeling runs were executed : the 1 st 

### run was f or E

- 1 giving the 1 st 

### acute and 1 st 

### chronic values and the 2 nd 

### run was for E

- 3 giving the 2 nd 

### acute and 2 nd 

### chronic values. The total of the 1 st 

### and 2 nd 

### acute val u es was taken to represent the acute EDWC for the total stressor while the total of the 1 st 

### and 2 nd 

### chronic values was taken to represent the chronic EDWC for the total stressor. This was based on two a ssumption s: parent degrades very quickly to E

- 1 and that E

2 is a transient degradate. It is noted , however, that this estimate is conservative because, even though it is reasonable to assume that at time zero (i.e., at application) approximately 100% of the pyraflufen

- ethyl transforms very quickly to E

- 1, not all the E

- 3 would be available at time zero as it forms much later in time ( E

- 3 may be considered as a terminal degradate)

. In 201 1 , all of the labeled uses , including previously assessed use patterns, were considered and modeled using Tier 2 PRZM
- EXAMS resulting in revised EDWCs of: 0.425 ppb for acute exposure, 0.295 ppb (annual average) and 0.268 ppb (30

- year average) for non

- cancer/cancer chronic exposures. The groundwater screening concentration did not change from the 0.002 ppb for acute/ chronic exposures . Again, the same EDWCs were used as exposure estimated for the new use assessment conducted later in 2012 9



### . In this assessment, four different modeling approaches were used: one modeling run for the combined parent with E

- 1 to arrive at t he 0.425 ppb acute exposure; a modeling run for parent with E

- 1 , E

- 2 , and E

- 3 to arrive at 0.295 ppb (annual average) and 0.268 ppb (30

- year average) for non

- cancer/cancer chronic exposures; a modeling run for parent with E

- 1 , E

- 2 , and E

- 3 using the lowest average partitioning rate (Koc) of the four components to arrive at an upper bound for the chronic exposure ; and a modeling run using the f

ormation and decline procedure assuming that parent with E

- 1 (as one parent) that degrades into E

- 2 with E

- 3 (as one degradate) . Th e last approach gives two separate ED WCs : one for parent pyraflufen

- ethyl with E

- 1 and the other for E

- 2 with E

- 3 using a feature in PRZM

EXAMS that is currently in the experimental stage. EDWC values were reported for the four approaches bu t the first two approaches were used in the assessment. Stressor for the drinking water assessments of 2002 (Tier 1 ) and 2011 (tier 2) consisted of parent, E

- 1, E

- 2, and E

- 3. This was based on the 2002 decision of the Metabolism Assessment Review

8 2008: Tier I Estimated Environmental Concentrations of Pyraflufen for the Use in the Human Health Risk Assessment (DP Barcodes: D337845, D342902, D343458, D343461 and D343914; dated February 29, 2008. This was an updated drinking water assessment that incorporated use site and/or rate and pattern data for Pyraflufen

ethyl for pastures, wheat, soybean, corn, pastures, sod farms, Christmas trees, nurseries, ornamental plantings, non

crop weed control; and for pre

- plant burn

- down on root and tuber vegetables, Cole crops, legumes, fruiting vegetables, cucurbits and small grains 2009: Tier I Drinking Water Assessment, for the Registration of the New Non

- Food Uses of Pyraflufen

- ethyl on Established Ornamental Turf Lawns (Residential, Ind ustrial, and Institutional), Parks, Cemeteries, Athletic Fields, Golf Courses (Fairways, Aprons, Tees, and Roughs), Sod Farms, and Similar Turf Areas (DP Barcodes: D361815, D361816; dated August 7, 2009) 9 2011: Drinking Water Assessment, for the Registrat ion of new uses of pyraflufen

- ethyl on tree nuts, stone fruit, pome fruit, hops, grapes, olives and pomegranates (DP Barcode:D377360; dated March 23, 2011) 2012: Drinking Water Assessment, for the Registration of New uses of Pyraflufen

- ethyl on Peanuts and Additional Registration on Hops (DP Barcode: 402766; dated October 4, 2012)

### 11

Committe e (MARC) 10



### . In absence of toxicity data, the decision was based on structural similarity of E

- 1, E

- 2, and E

- 3 to the parent (i.e., E

- 1, E

- 2, and E

- 3 were considered of similar toxicity to parent). In this MARC decision , degradate s U

- 1 ( a major soil photolys is degradate) and PD

- 1 (a major aqueous photolysis degradate) were not considered as residues of concern in drinking water. This is because U

- 1 results from soil photolysis ( not a major route of environmental degradation ) and PD

- 1 appeared to be relatively unstable in water.
I f necessary, a tier 2 drinking water assessment (from surface water) which will be similar to that conducted in 2011 for the total toxic residue of parent with E

- 1, E

- 2, E

- 3. The new assessment will consider any new uses and any chan ges in the characteristics of the chemicals in the residue of concern that might results from submittal of new studies. Additionally, previously estimated EDWCs for the ground water will be conducted using EFED new model PRZM

- GW 11 

### which may give different v alues compared to the previously used SCIGROW mode l

.


## c. Clean Water Act Programs Pyraflufen

- ethyl is not identified as a cause of impairment for any water bodies listed as impaired under section 303(d) of the Clean Water Act 12



### . In addition, n o Total Maximu m Daily Load s (TMDL) have been developed for [insert pesticide] 13 

### . More information on impaired water bodies and TMDLs can be found at the Agency’s website 14



### . The Agency invites submission of water quality data for th is pesticide . To the extent possible, s ubmissions should include the key data elements noted in the OPP Guidance for Submission of State and Tribal Water Quality Monitoring Data 15 

### in order to ensure they can be used quantitatively or qualitatively in pesticide risk assessments.


# 5. Environmental Fa te and Transport
Pyraflufen

- ethyl is relatively insoluble in water although it is expected to be in soluble form due to the low application rate (EECs to a depth of 15 cm resulting from the maximum labeled single application of 0.00895 lb. a.i/A = 0.0 044 p pm compared to a solubility of 0.082 ppm). The solubility of the chemical major degradates var y : E

- 1 six orders of magnitude higher; E

- 2 nearly two orders of magnitude higher and E

- 3 one order of magnitude higher. Pyraflufen

- ethyl is determined to have a v ery low vapor pressure and Henry’s Law Constant indicating that it is not likely to volatilize significantly from wet or dry surfaces. The octanol/ water partition coefficient s (K OW s 

### ) of pyraflufen

- ethyl and its degradate E

- 3 are relatively high (3 , 090 “ Lo g Kow= 3.49” and 4,750 “ Log Kow= 3.66” ) suggesting possible bio

- concentration in aquatic organisms such as fish. However, the other two major transformation products (E

- 1 and E

- 2) show much lower octanol/ water partition coefficient (794 and 759 suggesting low tendency to bio

- concentrate.

10 PP#1F06248. Pyraflufen ethyl on Cotton and Potato. Outcome of Health Effects Division (HED) Metabolism Assessment Review Committee (MARC) Meeting Held July, 2002. PC Code 03009 0, DP Barcode: D284438.

11 URL: http://www.epa.gov/oppefed1/models/water/przm_gw/wqtt_przm_gw_guidance.htm

12 http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885 13 http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_pollutant_group_name=PEST ICIDES 14 http://www.epa.gov/owow/tmdl/ 15 http://www.epa.gov/oppsrrd1/registration_review/water_quality_sop.htm

### 12

Pyraflufen

- ethyl shows a high potential to hydrolyze under alkaline conditions. The major transformation product is E

- 1, which resist s further hydrolysis at all pH levels tested. Pyraflufen

ethyl also undergoes photolysis quickly in water and on soil (half

- lives of about 2.5 and 2 days, respectively). The major transformation products were PD

- 1 and E

- 1 in water and on loamy sand , respectively

. Based on laboratory and field studies, parent pyraflufen

- ethyl was found to be short

- lived under most environmental conditions (half

- lives generally <2 days). The major transformation pathways are hydrolysis, photolysis and metabolism forming transformation products E

- 1, E

- 2 and E

- 3. The E

- 1 and E

- 2 transformation products show di fferent persistence patterns in different soils /aquatic systems depending on soil type, temperature and aerobici t y (refer to section 5) but E

3, which is the terminal degradate, is expected to be highl y persistent in the environment. A notable exception to this degradation pattern was the aqueous photolysis dissipation pathway , where PD

- 1 was a major transformation product. PD

- 1 did not appear to be persistent under photolytic conditions. For pyraflufen

- ethyl, E

- 1, E

- 2, and E

- 3, mobility was classified as slightly mobile, moderately mobile to mobile, slightly mobile, and slightly mobile, respectively (FAO Mobility Classification, FAO 2000 16 

### ). Terrestrial field dissipation studies conducted in CA and WA confirm that the major transformation products found in the field are E

- 1 and E

- 3. They were not present at significant amounts below the 6

- inch level. H alf

- lives of E

- 1 in the field were 1 1 days in CA and 161 days in WA . No field half

- lives w ere established for E

- 3

. In the soil system, parent pyrafluf en
- ethyl is expected to be short lived and therefore would not have ample time to leach. In contrast, the moderately mobile to mobile E

- 1 and the slightly mobile E

- 2 are expected to reside longer in the soil suggesting possibility for leaching. Finally, th e persistent/slightly mobile/low concentration degradate E

- 3 is not expected to leach in appreciable amounts. Therefore, the potential is for degradate E

- 1 and E

- 2 only to leach to ground water in vulnerable aquifers, such as those with coarse

- textured soi ls low in organic matter

. A summary of the physical/ chemical and Environmental Fate and transport properties of parent pyraflufen ethyl is presented in Table 3

. Table 3 Chemical Properties and Environmental Fate Parameters of Pyraflufen ethyl

P arameter V alue MRID No.
Chemical Name ethyl 2

- [2

- chloro

- 5

- [4

- chloro

- 5

- (difluoromethoxy)

- 1

- methylpyrazol

- 3

- yl]

- 4

- fluorophenoxy] acetate Chemical Structure Refer to Appendix 2 Molecular Weight (parent) 413.18 g mol

- 1 Solubility of parent (20 o C) 0.082 ppm (MRID 4 52828

- 05) Vapor Pressure of parent (25 o C) 1.6 x 10

- 8 torr

16 Food and Agriculture Organization of the United Nations. FAO PESTICIDE DISPOSAL SERIES 8. Assessing Soil Contamination: A Reference Manual. Appendix 2. Parameters of pesticides that influence processes in the soil. Editorial Group, FAO Inf ormation Division: Rome, 2000. URL: http://www.fa o.org/DOCREP/003/X2570E/X2570E00.htm

### 13 P arameter V alue MRID No. Henry’s Law constant 1.06 x 10

- 7 atm m 3 mol

- 1 (Estimated from vapor pressure and water solubility) Octanol

- Water Partition Coefficient (K OW , at 20 o C) 3,090 (log K OW = 3.49)

Hydrolysis Half

- li fe [pH 5, 7, 9 and 25 o C] Relatively stable ( 267 d ) at pH 5, 10.8 days at pH 7, 6.2 hrs at pH 8. Major and only hydrolysis product : E
- 1 , which increased to up to 6% at pH5, 83% at pH 7 and up to 100.0% at 30 d (study termination) 452830

- 17 (A cceptable= A )
Aqueous Photolysis (predicted ) environmental photo degradation Half

- life at pH 5 and 20 o C 2.5 days Major and only photoproduct : PD
- 1 (max. 32% at 36 hours, then declined to 19% after 48 hours) 453276

- 28 and 461627

- 02 ( Supplemental= S)

Soil Photolysis (predicted ) environmental photo degradation Half

- life at 25 o C Cannot be determined (t 1⁄2 = 2 days for irradiated samples

compared to <1 day for the dark control ) Major photoproduct : E
- 1 (max. 53

- 68% at 5 days declining to 17

- 19% at 30 days), U
- 1 (max. 5

- 21% at 30 days) and CO 2 (max. 6

- 25% at 30 days) Minor photoproduct : E
- 2 (max. 7%) and E
- 9 (max. 2%) 452830

- 19 (S)

Aerobic Soil Metabolism Half

life <0.25 days (LS, Fresno, CA; pH 6.7; OM 0.6%); <7 days (SSiL, UK; pH 5.3; OM 2.4%); <1 day (SL, UK; pH 4; OM 1. 9%); <0.25 days (CL, UK; pH 6.9; OM 5.9%) @ 20 and 25

o C ~1
- 1.7 days (SSiL , UK @ 10 o C ) Major degradates : E
- 1 , E
- 2 and E
- 3 in addition to E
- 11 and U
- 1 (in CA soil ) Minor degradates : E
- 9 , E
- 8 , U
- 1 and U
- 2 452830

- 20, 452830

- 21, 452830

- 22 (S)

Anaerob ic Aquat ic Metabolism Half

- life <4 hours ( clay sediment system from CA ) Major degradates : E
- 1 (92.3% at 1 day) and E
- 2 (93.0% at 62 days) 453276

- 29 (A)

Aerobic Aquatic Metabolism Half

- life <6 hours (Two water/clay loam, and a water/sand sediment systems from UK ) Major degradates : E
- 1 (99

- 100% at 2 days) and E
- 2 (increased throughout the study to a max. of 21

- 51% at 100 days

– last test interval). Minor degradates : E
- 3 (max. 9.91% at 100 days )

. E
- 1 was associated with the water and sediment layers; E
- 2 and E
- 3 was mostly associated with the sediment layer 452830

- 25 (A)

Mobility of Parent and Degradates in Soil Columns Two SL, SSiL and CL soil columns : 8 3

- 9 4 % in the 0

- 5 cm soil depth. Leachates contained variable amounts of pyraflufen

- ethyl, E

- 1, and E

- 2, wit h varying ratios, but the major component was E

- 1 in all cases. Other mino r components were E

- 3, and E

- 9 452830

- 26 (S)

### 14 P arameter V alue MRID No.

Mobility of Aged Parent and Degradates in one Soil Column S L from UK

– 30 day aging period: 68 , 30 , 4 and <0.3% in the 0

- 5, 5

- 10, 10

- 1 5 and 15

- 30 cm soil depths, respectively. 0.5% was found in the leachate. Following the aging period, pyraflufen

- ethyl was on the average 4%, E

- 1 was 51 % and E

- 3 was 13 % of the applied

. E

- 2 was not detected, but following the leaching period, it was pre sent at up to 26 % of the app lied in the 0

- 5 cm soil depth 452830

- 28 (A)

O rganic Carbon Partition Coefficient (K OC ) In a batch equilibrium study Pyraflufen

- ethyl was unstable when shaken for 2

- 4 hours in a SL from the UK 452830

- 29 (A) Organic Carbon Part ition Coefficient (K OC ) The log K OC for pyraflufen

- ethyl as determined using HPLC methodology is 3.3 ( K OC .~ 2000 ) MRID: 452830

- 30 (S)

Terrestrial Field Dissipation Half

- life Two studies conducted with radiolabeled material in Madera, CA and Ephrata, WA a t a rate of 30 g/ha. DT 50 in both sites were short (<6 hours), with near quantitative formation of E
1 . In CA, the half

- life for E

- 1 was 10.5 days and in WA, it was 161 days. Major degradates were E

- 1 and E

- 3. The residues of pyraflufen

- ethyl and its tra nsformation products were almost exclusively detected in the 0

- 15 cm soil layer. A significant fraction of the applied radioactivity was not extracted at later sampling intervals and increased to over 23

- 30% of the applied by the end of the study period. 452830

- 34, 452830

- 35 (A)



### It is noted that important fate studies, such as aqueous photolysis and aerobic soil studies (only one soil from the USA) are classified as supplemental due to various deficiencies that are stated in their respective data evaluat ion records (DERs). Also, the aerobic aquatic study used only one water/sediment system instead of the required two systems. Giving the fact that this chemical is applied at a relatively low rate, no new studies are required at this time. This may change if new registrations are requested with significantly higher application rates. Finally, a summary of the available physical/ chemical and environmental fate and transport properties is presented in Table 4 for degradates E

- 1, E

- 2 and E

- 3

. Detailed descrip tion of each degradation pathway are included in the “transformation products section ” below.
Table 4 Chemical Properties and Environmental Fate Parameters of E

- 1 , E

- 2 and E

- 3 ; P yraflufe n
ethyl D egradates
Parameter Value(s) MRID No(s). Chemical Names and Structures Refer to Appendix 2 Molecular Weight (parent) 413.18 g mol

- 1 Molecular Weight (g mole

1 ) E
- 1 = 385; E
- 2 = 327 and E
- 3 = 341 Solubility of E

- 1 (20 o C) E
- 1 = 1,020 ppm @pH 5; and 11,800 ppm @pH 9; E
- 2 = 7.60 ppm and E
- 3 = 0.53 ppm (MRIDs: 4 53276

- 09, 452828

- 07) Octanol

- Water Partition Coefficient K OW (log K OW) at 20 o C E
- 1 = 794 (2.90); E
- 2 = 759 (2.88) and E
- 3 = 4,570 (3.66)

### 15 Parameter Value(s) MRID No(s). Hydrolysis Half

- life of E

- 1 (pH 4, 7, 9; and 50 o C) E
- 1 = Stable 452830

- 18 (Acceptable= A)
Aerobic Soil Metabolis m for E

- 1 Half

- life from parent studies@ 20 and 25 o C 8.4 days (LS, Fresno, CA, pH=); 15 days (SSiL, UK); 11 days (SL, UK); 22 days (CL, UK) 452830

- 20, 452830

- 21, 452830

- 22 (Supplemental= S)

Aerobic Soil Metabolism for E

- 2 Half

- life @ 20 o C 9 days (Si L soil ; pH 6; OM 3.6% ); 10 days (SL soil ; pH 4;

OM 2.1% ); and 8 days (CL soil ; pH 7; OM 6.4% ) Major transformation product : E

- 3 (max. 30% at termination; No decline) Minor transformation product: U

- 1 and
un
- extractable residues (max. 39% at termination) 4 52830

- 23 (S)

Aerobic Soil Me tabolism for E

- 3 Half

- life @ 1 0 o C 330 days (SiL soil; pH 6; OM 3.6%); 495 days (SL soil; pH

4; OM 2.1%); and 154 days (CL soil; pH 7; OM 6.4%) Major transformation product : U

- 1 Minor transformation product: U

- 2, U

- 3 and U

- 4 452830

- 24 (S)

Mobility Batch Equilibrium of Degradate E

- 1

– Batch Equilibrium Study (K OC 

### in Lkg

- 1 ) 197 (SL soil); 100 (SL soil) and 82 (CL soil); Moderately mobile to mobile (FAO mobility classification) 452830

- 31 (S)

Mobility Batch Equilibrium of Degra date E

- 2

– Batch Equilibrium Study (K OC 

### in Lkg

- 1 ) 2,197 (SL soil); 2,145 (SL soil) and 1,424 (CL soil); Slightly mobile (FAO mobility classification) 452830

- 32 (S)

Mobility Batch Equilibrium of Degradate E

- 3

– Batch Equilibrium Study (K OC 

### in Lkg

- 1 ) 4,35 4 (SL soil); 4,173 (SL soil) and 3,098 (CL soil); Slightly mobile (FAO mobility classification) 452830

- 33 (S)

Bio

- concentration in Fish for E

- 1 E

- 1 (also known as pyraflufen) residues did not accumulate appreciably in rainbow trout ( Oncorhynchus mykis s ). The max. BCFs were as follows: whole body 2.4X, flesh 18.0X, carcass 3.3X. The exposure period was 7 days. 452828

- 03 (A)



## a. Transformation Products Upon application of pyraflufen

- ethyl most of parent pyraflufen

- ethyl will eventually reach the aerobic soil system earlier from direct soil application and later from plant wash

- off . Lower amounts of the chemical will reach aquatic systems by drift. The parent chemical reaching both the soil and aquatic system is expected to degrade rather quickly (with in one to two days) giving different suites of degradation products with varied physical/chemical and fate and transport properties. Parent reaching the soil system is expected to degrade into multiple degradation products including E

- 1, E

- 2, E

- 3, E

- 8, E

- 9, E

- 11, U

- 1, U

- 2 (refer to Appendix 2 for chemical names and structures) in addition to CO 2 

### and un

- extracted residues (not always measured) and unknown

### 16

minor degradates. In most of the soils tested the major degradates were E

- 1, E

- 2 and E

- 3 (refer to Table 3 ). Almost complete transformation of parent into the first degradate, E

- 1 was observed in all aerobic soils tested in the short

- term (Maximum reached 75 to 95% within 1

- 7 days) noting that it reached the maximum of 89% at 28 days when one of the se soils (s oil 2) was incubated at low temperature ( 10 o 

### C compared to 20

- 25 o 

### C )

. Th is first degradate, E

- 1 is expected to be moderately persistent in most aerobic soils at temperatures between 20

- 25 o 

### C and appears to be highly persistent at lower temperatures such as 10 o 

### C ( Table 5 ).
Table 5 Major degradation products of pyraflufen

- ethyl in four aerobic soils Item/Soil Soil 1 (CA, USA) Soil 2 (UK) Soil 3 (UK) Soil 4 (UK) Soil 2 (UK) Parent Label Both Labels * pyrazole

- 5

- 14 C] Temperature o C 25 20 20 20 10
Texture Sa ndy Loam Sand Silt Loam Sandy Loam Clay Loam Sand Silt Loam pH (I M KCl) 6.7 5.3 4 6.9 5.3 Organic Matter 0.6 2.4 1.9 5.9 2.4 Study Duration 366 d 179 d 179 d 179 d 178 d Parent t 1⁄2 <1 d <1 d <1 d <1 d 1

- 2 d E

- 1 t 1⁄2 60 53 22 25 328 Degradate E
- 1 % Max Reached (time) ** 95% (3 d) 84% (7 d) 75% (3 d) 84% (1 d) 89% (28 d) Declined to% (time) ** 1% (366 d) 8% (179 d) 3% (179 d) 3% (179 d) 56% (179 d) Degradate E
- 2 % Max . R eached (time) 15% (21 d) 39% (100 d) 36% (28 d) 7

- 8% (28

- 179 d) 23% (178 d) De clined to% (time) 2% (366 d) 24% (179 d) 31% (179 d) No decline No decline Degradate E
- 3 % Max

. Reached (time) 37

- 44% (238

- 366 d) 38% (179 d) 21

- 24% (28

- 179 d) 52

- 55% (66

- 179 d) 5

- 6% (63

- 179 d) Declined to% (time) No decline No decline No decline No dec line No decline * Note: The two labels [pyrazole

- 5

- 14 C] and [phenyl

- U

14 C] labels was used in the study. However, data presented in this Table are the [pyrazole

- 5

- 14 C] label due to inappropriate sampling frequency used in the [phenyl

- U

14 C] label ** For e xample degradate E

- 1 reached a maximum of 93% of the applied at day 3 then declined afterwards to 1% of the applied at 366 days.


### The second major aerobic soil degradate is E

- 2 with observed maximums/timing and persistence

that vary by incubation temperat ure and soil characteristic (maximums of 7

- 39% occurring at 21 to 179 days). E

- 2 shows slight decline (low persistence) in three soils (reached 2

- 31%) and no decline (high persistence) in two soils (soil 4 and soil 2 at 10 o 

### C , Table 5 ). When E

- 2 was used a s a test material and incubated at 2 0 o 

### C , m uch lower persistence was observed in three soils (t 1⁄2 ranged from 8 to 10 days ( Table 4 ) transforming into the third major degradate of pyraflufen

ethyl E

- 3 (maximum of E

- 3 forming from E

- 2= 30% at study terminati on with no decline ) . Based on this data it is clear that E

- 3 forms from E

- 2 and that its concentration and timing of presence in the soil system can be at the mid

- term or the long

- term depending on soil type and temperature

. The third major aerobic soil degra date is E

- 3 with observed maximums of 5

- 55% occurring at the termination of the experiment in all soils tested ( Table 5 ). E

- 3 is expected to be highly persistent

### 17

in all soils but forming at variable quantities. The same high persistence wa s observed in three soils when E

- 3 was used as a test material (t 1⁄2 ranged from 154

- 495 days ( Table 4 ) transforming into multiple unknowns. Based on data presented in Table 5 above, parent is expected to degrade very quickly and almost completely into E

- 1 with a max imum observed transformation of 95% of the applied parent. Therefore, acute or short

- term exposure is expected to be associated with parent and E

- 1. E

- 1 transf orms into E

- 2 and E

- 2 resident time , in the soil system, var i es from soil to soil (medium to lon g term) with a maximum observed transformation of 39% of the applied parent

. Therefore, medium

- term exposure is expected to be mainly associated with E1 and E

- 2. E

- 3 is expected to be the terminal/persistent degradate and associated with the long

- term ch ronic exposure with a maximum transformation of 55% of the applied parent. In some soils, E

- 2 may also be present at the long

- term exposure.
The l ower amounts of applied parent reach ing aquatic systems by drift are expected to transform very quickly (wit hin hours) into E

- 1 degradate with a maximum observed transformation of 100% and 92% of the applied parent in aerobic and anaerobic systems, respectively

. Therefore, acute or short

- term exposure is expected to be mainly associated with E

- 1. E

- 1 transform s into E

- 2 and E

2 concentration level , in the aquatic system, varies depending on the aerobicity of the system with a maximum observed transformation of 51 % and 93% of the applied parent in aerobic and anaerobic systems, respectively . Therefore, medium

- te rm exposure is expected to be mainly associated with E

- 2. E

- 3 is expected to be the terminal/persistent degradate and associated with the long

- term chronic exposure with a maximum transformation of 10 % of the applied parent in only aerobic systems. E

- 3 w as not observed in anaerobic systems where E

- 2 appears to be extremely persistent and therefore would be the major component of chronic risk (unless additional transformation had already occurred prior to the system becoming anaerobic)

. 

# 6. Receptors

As descr ibed in the Agency's Overview Document (U.S EPA, 2004), the most sensitive endpoint for each taxonomic group will be used to calculate risk quotients (RQs). Assessment endpoints include direct toxic effects on the survival, reproduction, and growth of terr estrial and aquatic life as well as indirect effects such as reduction in prey base and/or modification of habitat. Acute and chronic toxicity data from studies submitted by pesticide registrants along with the available open literature are used to evalua te the potential direct effects of pyraflufen

- ethyl to the aquatic and terrestrial receptors identified in this section. This includes toxicity data on the technical grade active ingredient, degradates, and when available, formulated products. The open lit erature studies are identified through EPA's ECOTOX database (http://cfuub.epa.gov/ecoto20, which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife. A summary of the available ecoto xicity information and the incident information for pyraflufen

ethyl are provided below. Table 9 provides a summary of the taxonomic groups and the surrogate species tested to help understand potential acute and chronic ecological effects of pyraflufen

eth yl . In addition, the table provides a preliminary overview of the potential acute toxicity of pyraflufen

- ethyl by providing the acute toxicity classifications.

### 18

Pyraflufen

- ethyl generally did not elicit a 50% mortality response in all aquatic acute toxic ity tests that are available nearing and up to the limit of solubility ( 0.082 mg/L ). For the three species for which they are available, formulated pyraflufen

- ethyl showed a mixed response in terms of being equal or greater toxicity than parent pyraflufen

- ethyl. Chronic toxicity studies with daphnia magna show no effects up to the solubility limit of pyraflufen

- ethyl. Two chronic early life stage studies with fathead minnow (one with standard and one with enhanced light conditions) showed about a 3.5 fol d increase in toxicity of enhanced light over standard light (both had most sensitive endpoint as weight). Aquatic vascular and non

- vascular plant studies showed effects on frond and cell density; respectively well below the limit of solubility. Addition ally, available studies for the degradate E

- 1 indicate that it is at least two orders of magnitude less toxic than parent, depending on the taxa. Terrestrial studies indicated a general lack of toxicity for birds (acute oral and sub

- acute dietary based) a nd mammals (acute and chronic). In one avian reproduction study with the northern bobwhite quail, pyraflufen

- ethyl did not exhibit any adverse effects on any reproductive parameter up to and including the highest treatment concentration (4836 ppm). In th e companion mallard duck study, several effects were observed ( including eggs laid, eggs set, viable embryos, viable embryos/eggs set, live

- 3 week embryos, number hatched, number hatched/eggs laid, number hatched/eggs set, number hatched/live 3

- week embry os, hatchling survival, hatchling survival/eggs set, hatchling weight, survivor weight, food consumption, and female weight gain). T his study was determined to be invalid due to the stability of the test substance in the treated feed. However, given the deficiencies in the study where effects were seen, a lack of effects in the other avian reproduction study, an absence of effects in acute and chronic studies for mammals, and the known herbicidal mode of action of pyraflufen

- ethyl, further avian reproduct ion studies would not provide an added benefit to the risk assessment. Furthermore, the highest pyraflufen

- ethyl application rates are currently 0.00894 lbs a.i/A (2 applications at a 7

- day interval) , which means that n additional avian reproduction study would have to exhibit effects at three orders of magnitude below where the effects were observed in the original mallard study.



## a. Effects to Aquatic Organisms
Table 7
. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for Pyraflufen

- ethyl

Taxonomic Group Study Type Surrogate Species Toxicity Value (all units in terms of measured active ingredient ) 2 Acute Toxicity

Classification Source

(Classification)

Freshwater fish 1 Acute Bluegill Sunfish ( Lepomis macrochirus ) LC 50 = >85 μg/L (N/ A; N/A) Very highly

toxic 45327604

(Acceptable)

Acute (formulation) Rainbow Trout

( Oncorhynchus mykiss ) LC 50 = 0. 42 μg /L (37

- 47; 12.9) Very highly

toxic 45282723

(Acceptable)

### 19

Taxonomic Group Study Type Surrogate Species Toxicity Value (all units in terms of measured active ingredient ) 2 Acute Toxicity

Classification Source

(Classification)

Chronic (Early Life

Stage) Fathead minnow

( Pimephales promelas ) NOAEC = 3.4 μg/L LOAEC = 7.2 μg/L Endpoint: 35

- day length, weight -- 45389205 (Supplemental)

Chronic (Early Life

Stage

– enhanced light conditions ) NOAEC = 0.89 μg/L LOAEC = 1.6 μg/L Endpoint: 32

- day weight -- 48409701 (Supplemental)

Freshwater invertebrates A cute Water Flea ( Daphnia magna ) EC 50 = >82 μ g/L (N/A; N/A) Very highly

toxic 45282713

(Supplemental)
Acute (formulation) Water Flea

( Daphnia magna ) EC 50 = 0.02 mg/L (N/A; N/A) Very highly

toxic 45282724

(Acceptable)

Chronic Water Flea NO A EC = 81 μg /L LO A EC = >81 μg /L Endpoint: None affected -- 45389201 (Acceptable)

Estuarine/marine fish Acute Sheepshead Minnow ( Cyprinodon variegat u s ) LC 50 = >56 μg /L (N/A; N/A) Very highly

toxic 45389204

(Supplemental)

Estuarine/marine invertebrates Acute Mysid Sh rimp ( Americamysis bahia) L C 50 = >60 μg /L (N/A; N/A) Very highly

toxic 45389203

(Supplemental)
Eastern oyster ( Crassostrea virginica L C 50 = >43 μg /L (N/A; N/A) Very highly

toxic 45389202

(Supplemental)

Aquatic plants and algae Vascular Duckweed ( Lemn a gibba ) NO A EC = 2.4 μg /L EC 50 = 16 μg / L (31

- 36; N/A) Endpoint: Frond density -- 45282728 (Acceptable)

Non

- vascular Freshwater diatom

( Navicula pelliculosa ) NO A EC = 0. 05μg /L EC 50 = 1.5 μg /L Endpoint: Cell density -- 45282729 (Acceptable)

1 Freshwater fish may be surrogates for aquatic

- phase amphibians. 2 Numbers in parenthesis following ECx estimates are 95% confidence intervals; slope (when applicable)

### 20

Table 8 . Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for E

- 1
Taxonomic Group Study

Type Surrogate Species Toxicity Value (all units in terms of measured active ingredient ) Acute

Toxicity Classification Source

(Classification)

Freshwater fish 1 Acute Bluegill Sunfish ( Lepomis macrochirus ) LC 50 = 90 mg/L Slightly toxic 4528271 2 (Supplemental)

Chronic (Early Life Stage) Fathead minnow

( Pimephales promelas ) NOAEC = 10 mg/L

LOAEC = >10 mg/L Endpoints: None affected -- 45282719 (Supplemental)

Freshwater invertebrates Acute Water Flea ( Daphnia magna ) EC 50 = >121 mg/L

(N/A; N/A) Practically non

toxic 45282715

(Acceptable)

Chronic NOAEC = 99 mg/L LOAEC = 120 mg/L Endpoints: Reproduction -- 45282720 (Supplemental)

Estuarine/marine fish Acute Sheepshead Minnow ( Cyprinodon variegat u s ) LC 50 = >99 mg/L Slightly toxic 45282718 (Supp lemental)

Estuarine/marine invertebrates Acute Mysid Shrimp ( Americamysis bahia) L C 50 = 9.4 mg/L

(6.1

– 13) Moderately

toxic 45282717

(Acceptable)

1 Freshwater fish may be surrogates for aquatic

- phase amphibians. 2 Toxicity endpoints presented, i.e. , NOA EC or EC 50 , are the only ones available from the study. 3 Numbers in parenthesis following ECx estimates are 95% confidence intervals; slope (when applicable)


## b. Effects to Terrestrial Organisms
Table 9 . Summary of the Most Sensitive Endpoints from Terrest rial Toxicity Studies for Pyraflufen

- ethyl
Taxonomic Group Study Type Surrogate Species Toxicity Value

(all units in terms of measured active ingredient) Acute

Toxicity Classification Source

(Classification)

Birds 1 Acute Bobwhite quail ( Colinus virginianu s ) LD 50 = > 2000 mg/kg

bw (N/A; N/A) Practically non
- toxic 45282704

(Acceptable)

Sub

- acute dietary Bobwhite quail LC 50 = > 50 00 mg/kg

- diet (N/A; N/A) Practically non
- toxic 45282707

(Acceptable)

Chronic Bobwhite quail NOA EC = 4836 ppm LOAEC = >4836 ppm -- 45327603 (Supplemental)

### 21

Taxonomic Group Study Type Surrogate Species Toxicity Value

(all units in terms of measured active ingredient) Acute

Toxicity Classification Source

(Classification)

Mammals Acute Oral Laboratory rat ( Rattus norvegicus ) LD 50 = >5000 mg/kg

bw Practically non
- toxic 45327615

Acute Inhalation Laboratory rat LC 50 = 5.03 mg/L Toxicity Category I V 45282821

Chronic Laboratory rat NOAEL = 10000 ppm LOAEL = >10000 mg/kg/day Endpoint: None -- 45282922

Insects Acute

contact /oral combination study Honey bee

( Apis mellifera L. ) Contact LD 50 = >1 12

μg/bee (N/A; N/A) Oral LD 50 = >100 μg/bee (N/A; N/A) Practically non
- toxic 45282732

(Acceptable)

Terrestrial plants Seedling

Emergence Dicot

– lettuce

( Lactuca sativa ) EC 05 = 0.0001 lb/A

EC 25 = 0.001 lb/A (0.00002

– 0.07; N/A) Endpoint: shoot dry weight

-- 45282725 (Acceptable)
Monocot

– None NOAEC = 0.009

lbs/A EC 25 = >0.009 lbs/AA Endpoint: N/ A

Vegetative Vigor Dicot

– Turnip

( Brassica rapa ) NOAEC = 0.000007

lb/A EC 25 = 0.0001 lb/A (0.000002

– 0003; N/A) Endpoint: shoot dry weight

-- 45282727 (Acceptable)

Monocot

– Onion ( Allium cepa ) NOAEC = 0.0005

lb/A EC 25 = 0.001 lb/A (0.0004

– . 002 ; N/A) Endpoint: shoot dry weight

Determination of Multiple Applications on Early Seedling Growth (Non guideline) Dicot

– lettuce

( Lactuca sativa ) NOAEC = 0.026 lb/A

EC 25 = 0.096 lb/A (0.038

– 0.22; N/A) Endpoint: root dry weight

-- 45282727 (Supplemen tal) Monocot

– Ryegrass ( Lolium perenne ) NOAEC = <0.096

lb/A EC 25 = <0.096 lb/A (N/A; N/A) Endpoint: root dry weight 1 Birds represent surrogates for terrestrial

- phase amphibians and reptiles.

### 22

In addition to the studies listed above, there is also a 2 1

- day freshwater midge sediment study (MRID 46641601), a subchronic earthworm toxicity study (MRID 45282733) , and an acute contact toxicity study with the predacious mite ( Typhlodromus pyri) (MRID 45282801). In the freshwater midge study (conducted wit h Chironomus riparius ), pyraflufen

- ethyl was spiked into the overlying water at 5 concentrations in a static system. Emergence rate and development rate was examined with the 21

- day NOAEC determined as the highest mean measured concentration tested (54 μg a.i/L). While the study was determined to be scientifically sound, EPA recommends spiked sediment studies rather than spiked water. The study also failed to measure concentrations in the pore water and it was uncertain from this study whether the water column concentrations that were achieved are reflective of the maximum concentrations that may occur from the labeled use of pyraflufen

- ethyl. In a subchronic earthworm toxicity study, pyraflufen

- ethyl caused no mortality or significant changes to body we ight after 14

- days of exposure at nominal concentrations of up 1000 mg/kg. In an acute contact toxicity study with the predacious mite, formulated pyraflufen

- ethyl (ET

- 751 2.5% EC) was applied at a single dose of 1.6 L/ha for 14 days. At test termination , t he number of eggs and larvae per female in the control group were 1.64 and 0.28, respectively. In the treatment group, the number of eggs and larvae per female were 0.64 and 0, respectively. The LC 50 

### could not be estimated, because there was only one treatment level; however, it was empirically determined to be 4.6 L/ha, based on mortality and reproduction (# of eggs and larvae/female). The NOEC was determined to be < 1.6 L / ha, based on significant reductions in mite mortality and reproduction at the si ngle treatment level. Although there are only three studies for which data are available, it is indicated by these studies that formulated pyraflufen

- ethyl (as the TEP ET

- 751 2.5% EC) may have greater toxicity than TGAI pyraflufen

- ethyl . Two acute fres hwater fish studies (one conducted with rainbow trout and ne with the bluegill sunfish) and one acute freshwater invertebrate study each are available to TGAI and formulated pyraflufen

- ethyl. Results of these studies show a more sensitive endpoint by abou t a factor of 2 for the rainbow trout (TGAI LC 50 

### = >101μg a.i/L vs. TEP LC 50 

### = 42 μg a.i/L). Although the rainbow trout TGAI is non

- definitive, the study showed no mortality effects up to the solubility limit of parent pyraflufen

- ethyl (82 μg a.i/L). A s imilar trend is seen when comparing results of the acute freshwater invertebrate studies (TGAI LC 50 

### = >82 μg a.i/L vs. TEP LC 50 

### = 20 μg a.i/L). Again, the TGAI study showed no effect on mortality up to the solubility limit. These results contrast with th ose of the bluegill sunfish studies (TGAI LC 50 

### = >85 μg a.i/L vs. TEP LC 50 

### = 86 μg a.i/L). It is an uncertainty about whether there exists a marked increase of toxicity for formulated pyraflufen

- ethyl vs. that of TGAI. ECOSAR Analysis of the Degradates of Pyraflufen
- ethyl
As described in Section 5a, pyraflufen

- ethyl degrades by various routes in the environment up to three different degradation products that are considered to be major , depending on the route of degradation ( Table s 5 and 6 ). The ECOSAR (v1.0) module of E PI S UITE (v.4.0) was employed to estimate the toxicity of these degradates as compared to registrant submitted data of parent pyraflufen

- ethyl . ECOSAR uses structure activity relationships to predict the toxicity of compounds that share similar structural moieties. In cases where multiple estimates of toxicit y

### 23

for a particular taxa are pre dicted for adegradate, the most sensitive estimate was tabulated

. Table 10 shows the ECOSAR classes for each degradate for which toxicity es t imates we re predicted. These results are compared alongside registrant submitted data that is available for pyraflufen

- ethyl as well as the degradate E

- 1. For each ECOSAR class, varying numbers of data points are associated in building the structure activity rela tionship that informs the estimate of toxicity for a given ECOSAR class. While estimates of toxicity provided by ECOSAR are less reliable than those of actual laboratory studies, ECOSAR class estimates that are associated with several endpoints generally have less uncertainty associated with them than those ECOSAR classes that only have a few.
Table 10. ECOSAR predicted toxicity (μg a.i./L) of the degradates of pyraflufen

- ethyl 3

Compound (Chemical class) Toxicity Endpoint (μg a.i/L)

Acute FW Fish LC 50 Acute FW Invertebrate EC 50 Chronic

FW Fish NOAEC Chronic FW

Invertebrate NOAEC Acute

E/M Fish LC 50 Acute E/M Invertebrate LC 50 Green

Algae EC 50 Parent pyraflufen
- ethyl Pyraflufen

- ethyl (registrant submitted studies)

– TGAI 4 >85 >82 3.4 (TGAI

– normal l ight conditions ); 0.89 ( TGAI

- high light conditions) 81 >56 >60 1.5
Pyraflufen

- ethyl (registrant submitted studies)

– TEP 4 0.42 0.02
Pyraflufen

- ethyl (Esters) 5 1170 1 1792 1 48 537 1495 1 358 484 Pyraflufen

- ethyl (Pyrazoles/pyrroles) 5 815 1457 1 31 2 55 2 77 Degradate E
- 1 E

- 1 (registrant submitted studies)

– TGAI 90000 >121000 10000 99000 >99000 9400

-- E

- 1 (pyrazoles/pyrroles

acid) 21408 1 35231 1 960 2 1550 2 2453 Degradate E
- 2 E

- 2 (phenols) 1057 881 158 167 195 3251 E

- 2 (pyrazoles/pyrroles) 1422 2386 61 2 101 2 156 Degradate E
- 3 E

- 3 (pyrazoles/pyrroles) 702 1250 27 2 47 2 67 Degradate PD
- 1 PD

- 1 (Esters) 8008 1 14285 1 446 6478 1 11161 1 5431 1 4849 1 PD

- 1 (Vinyl/allyl ethers) 1839 5315 1 44 2 1432 2 6104 1 PD

- 1 (Vinyl/allyl alcohols) 4840 1 759 38 2 17 2 8951 1

PD

- 1 (pyrazoles/pyrroles) 5474 1 8401 1 279 2 422 2 735

### 24 1 Indicates that chemical may not be soluble enough to measure this predicted effect 2 Indicates that this value was estimated using an acute

- to

- chronic ratio (ACR) 3 The lowest toxicity estimate for a given taxa was used when estimates for more than one ECOSAR class were yielded for a given degradate. 4 Data in this column refer to registrant submitted studies for pyraflufen

- ethyl deemed suitable for risk estimation. These values are included in t he table for comparison purposes against the ECOSAR predicted endpoints. 5 Data in this column refer to ECOSAR estimates of toxicity for parent pyraflufen

- ethyl 

### Table 10 shows that when comparing registrant submitted data for the taxa that are available, d egradate E

- 1 is at least two orders of magnitude less toxic than parent pyraflufen

- ethyl and some cases three orders of magnitude less toxic. This finding is significant given the previous discussion in the assessment that parent pyraflufen

- ethyl is short lived in the aquatic media, rapidly transforming to E

- 1 in one to two days. The toxicity profile beyond E

- 1 is uncertain however, as there are currently no registrant submitted toxicity data available for either E

- 2 or E

3.
With E

- 2, ECOSAR returned e stimates of two classes, phenols and pyrazoles/pyrroles. For the phenol class of E

- 2, there were several data points that comprised the estimate of each taxa and results indicated that E

- 2 is generally at least one order of magnitude less toxic than par ent pyraflufen

- ethyl. The second ECOSAR class associated with E

- 2, pyrazoles/pyrroles in contrast had very low numbers of data points with each estimate (in some cases, less than 3 data points). While the estimates from this class show generally less tox icity than parent pyraflufen

- ethyl, these results should be viewed as highly uncertain. The ECOSAR results of E

- 2 indicate generally less toxicity than parent pyraflufen

- ethyl, but greater toxicity than that of E

- 1, from which E

- 2 is formed. Based on the previous discussion however, E

- 2 itself is a transient degradate, giving way to E

- 3.
The ECOSAR results of E

- 3 are also highly uncertain given that the only ECOSAR class informing estimates of toxicity for this degradate are the pyrazoles/pyrroles class that have the same uncertainties associated with it as they did for E

- 2. The results of E

- 3 indicate generally less toxicity than parent pyraflufen

- ethyl but greater toxicity than E

- 1 and generally greater toxicity than E

- 2, from which it is formed.
Fina lly, ECOSAR results for the aqueous photolysis degradate PD

- 1 was supported by 4 ECOSAR classes; esters, vinyl allyl ethers, vinyl allyl alcohols, and pyrazoles/pyrroles. The results from the ECOSAR classes of pyrazoles/pyrroles and the high uncertainty w ith those estimates based on a small number of data points has been previously discussed with regards to the E

- 2 and E

- 3 degradates. Similarly, the vinyl allyl/ethers and vinyl allyl/alcohols classes are also associated with a very small number of data po ints that make comparisons to these classes highly uncertain. The esters class is associated with a higher number of data points for each taxa and indicates that PD

- 1 is 2

- 4 orders of magnitude less toxic than parent pyraflufen

- ethyl.
Given these resul ts that indicate E

- 1 is orders of magnitude less toxic than parent pyraflufen

- ethyl but give way to potentially more toxic E

- 2 and E

- 3, it is important to establish the concentrations at which E

- 2 and E

- 3 will ultimately be present. Parent pyraflufen

- ethy l has very low (less than 0. 0 1 8 lbs a.i/A) application rates associated with it and therefore the concentrations that will eventually be available to transform to E

- 2 and E

- 3 are important to consider when weighing the need for additional toxicity data on these degradates. See Section 11 for more information.

### 25



## c. Ecological Incidents The ecological incident information system (EIIS) is an OPP database that houses ecological incidents that have been reported to the Agency. When available, EIIS includes dat e and location of an incident, type and magnitude of effects observed in various species, use(s) of pesticides known or suspected of contributing to the incident, and results of any chemical residue analysis or other analyses conducted during incident inve stigation. EIIS incidents are categorized according to the certainty that the incident resulted from pesticide exposure. The Avian Monitoring System (AIMS) is a database administered by the American Bird Conservancy that contains publicly available data on reported avian incidents involving pesticides. Many of the incidents listed in this database are also in the EIIS.
EIIS returned one terrestrial plant incidents in California attributed to pyraflufen

- ethyl use with “possible” certainty (USEPA, 2007 b ) . Incident #I0 23587

- 0 0 6 occurred in October 2011. An unidentified farmer filed a claim reporting $250,000 worth of economic loss to 25 acres of Chinese leafy vegetables had been damaged by suspected aerial application of paraquat to cotton on a nearby f

ield. Further investigation by county officials determined that ET Defoliant/Herbicide (Pyraflufen

- ethyl) had been applied to a cotton site across the road to the farm from the southwest corner of the vegetable site. Seven foliage samples were taken and submitted to the Center for Analytical Chemistry for Analysis.
As of February 24 , 201 4 , the ITRMD maintained Incident Database System (IDS) and the Aggregate Incident System identified no ecological incidents involving pyraflufen

- ethyl. Additionally , the Avian Incident Monitoring System, maintained by the American Bird Conservancy, did not identify any ecological incident to birds resulting from the use of pyraflufen

- ethyl. 

# 7. Exposure Pathways of Concern
The environmental fate properties and use pattern s of pyraflufen

- ethyl indicate that direct spray, spray drift, leaching to ground water and runoff represent potential transport mechanisms of pyraflufen

- ethyl residues to aquatic and terrestrial organisms. For aquatic systems, parent pyraflufen

- ethyl s hould not be available for runoff but may reach the aquatic systems by drift. Parent reaching the aquatic system by drift is very short

- lived and would not be the main species present in aquatic systems. E

- 1 is moderately persistent in the soil , making it available for runoff during rain events occurring after application and it also forms from parent reaching these systems by drift (almost 100% transformation)

. Formed E

- 2 (from E

- 1) and E

- 3 ( from E

- 2) are more persistent in the soil and are expected to rea ch aquatic systems by run

off . E

- 3 is a highly persistent degradate (terminal degradate) and is expected to reach aquatic systems by run

- off in eroded soil because of its affinity to soil (Koc range from 3,098 to 4,354 L Kg - 1 

### ). For ground water, parent i s not expected to be leached due to its short half

- life in the soil system

. However, E

- 1 is expected to leach into groun d water (moderately persistent and moderately

### 26

mobile to mobile). E

- 2 and to a low er extent E

- 3 may leach (both are persistent but E

- 2 is at the low limit of the slight mobility class and E

- 3 at the high limit of the slight mobility class). For terrestrial systems, the exposure pathways include direct spray and spray drift to adjacent areas to treated fields. Exposure is expected to be ass ociated with parent residues unless the chemical is transformed into PD

- 1 by photolysis on wet foliage. It not likely that this photolysis degradate will persist for a long time on the foliage because it appeared to decline in the lab study and because it will be subject to wash

- off. Other exposure pathways to terrestrial species Potential for Risk to Terrestrial Organisms from Drinking Water Exposure
The S creening I mbibition P rogram (SIP v.l. 0 ), Released June 15, 2010) was used to calculate an upper bou nd estimate of exposure using pyraflufen

- ethyl’s solubility ( 0.082 mg/L), the most sensitive acute and chronic avian toxicity endpoints ( northern bobwhite quail duck LD 50 

### of > 2000 mg a.i/kg

- bw and northern bobwhite quail NOAEC of 4836 ppm, respectively) an d the most sensitive acute and chronic mammalian toxicity endpoints (Norway rat LD 50 

### of > 5000 mg a.i/kg

bw and Norway rat NOAEL of 10 0 00 ppm, respectively). Drinking water exposure alone was not determined to be a potential pathway of concern for both avi an and mammalian species on both an acute and chronic basis. Although drinking water exposure alone does not appear to be of concern, this does not take into account that when aggregated with other exposure pathways (dietary food sources, dermal, inhalati on) drinking water may contribute to a total exposure that has a potential for effects on non
- target animals and should be explored further. Because there is a high degree of conservatism in the SIP 1.0 exposure estimate, there is a limited expectation tha t use scenarios not triggering a SIP 2.0 concern would contribute significantly to aggregate risks from water plus diet when a refined water exposure model is incorporated in the actual quantitative risk assessment. Detailed information about SIP v.l. 0 as well as he tool can be found on the EPA's website at http://www.epa.gov/pesticides/science/models/pg.htm#terrestrial
Potentia l for Risk to Terrestrial Organism from Inhal ation Exposure
The S creening T ool for I nhalation R isk (STIR v.l. 0 , November 19, 2010) was used to calculate an upper bound estimate of exposure using pyraflufen

- ethyl’s vapor pressure and molecular weight for vapor phase exposure as well as the maximum ap plication rate and method of application for spray drift. STIR incorporates results from several toxicity studies including acute oral and inhalation rat toxicity endpoints obtained from the "six pack," of core studies, which are a series of six guideline studies that are submitted to the Registration Division of the Office of Pesticide Programs for technical and formulated products of a pesticide (oral LD 50 

### = > 5000 mg a.i/kg

- bw and inhalation LC 50 

### = >5.03 mg/L ) as well as the most sensitive acute oral avia n toxicity endpoint (mallard duck oral LD 50 = >500 mg a.i/kg

- bw). Based on the results of the STIR model, inhalation exposure alone was not determined to be a potential pathway of concern for avian and mammalian species on an acute basis.

### 27

Inhalation expos ure via spray drift and/or vapor

- phase of pyraflufen

- ethyl alone does not appear to be of concern. The analysis of the inhalation route in STIR does not consider that aggregation with other exposure pathways such as dietary, dermal, or drinking water may c ontribute to a total exposure that has a potential for effects to non

- target animals. However, the Agency does consider the relative importance of other routes of exposure may be potentially significant contributors to wildlife risk (US EPA, 2004). Detaile d information about STIR v.l. 0 , as well as the tool, can be found on the EPA's website at : http://www.epa.gov/pesticides/science/models/pg.htm#terrestrial Dermal exposur e Potential exists for pyraflufen

- ethyl dermal exposure to terrestrial wildlife. At the present time, the Agency does not have a method to quantify levels of dermal exposure from chemical applications, but is actively working on a screening tool to accoun t for this route of exposure.


# 8. Analysis Plan
The ecological and drinking water risk assessment s will focus on pyraflufen

- ethyl and its major degradates (E

- 1, E

- 2 and E

- 3 ) as the main stressor of concern for important exposure pathways specified above in Section 7 . Exposure EECs will be modeled for affected environmental compartments using various environmental fate and transport models. The EECs will be compared with toxicological endpoints from various aquatic and terrestrial taxa to quantitatively com pute risk quotient s (RQ s ). The RQ s will be compared to the Agency’s levels of concern (LOC) to determine the risk to organisms resulting from exposure pyraflufen

- ethyl and its residues following applications.



## a. Stressors of Concern
i. Ecological Risk Assessm ent
The stressor of ecological concern for terrestrial organisms is parent pyraflufen

- ethyl and its major degradates E

- 1, E

- 2, and E

- 3

. It is noted that the photolysis degradate PD

- 1 may form upon contact with foliage . Ho w ever, PD

- 1 showed de cline with continued light exposure and any that may form is expected to be less than or of equal toxicity to the parent (PD

- 1 is structurally similar to parent with OH substitution to Cl). As indicated in Section 6, PD

- 1 is shown by ECOSAR analysis to be at least 2 orders of magnitude less toxic than parent pyraflufen

- ethyl. Please see the section “ ECOSAR Analysis of the Degradates of Pyraflufen

- ethyl ,” in Section 6 for information on the EOCSAR estimates of the other degradates.
The stressor of concern for aquati c organisms is the combined parent pyraflufen

- ethyl and degradates E1, E

- 2 and E

- 3 and surface water exposure EEC averages will be obtained by modeling the total toxic residue of parent+ E

- 1+ E

- 2+ E

- 3 assuming similar toxicity. In this respect, it is noted that major acute exposure is expected from E1 and chronic exposure from E

- 3 and possibly E

- 2+ E

- 3 when run

- off is originated from soils in which E

- 2 is persistent (refer to transformation products section for more information). A different approach may be used, by calculating exposure EECs for individual species in the stressor depending on degradates toxicity

### 28

data that may become available. Due to the fact that some toxicity data are available for E

- 1 degradate, risk quotas (RQs) will be calculated using acute total toxic residues EECs divided by available acute toxicity of E

- 1. When acute toxicity are not available for E

- 1 parent data will be used (assum ption of similar toxicity to parent).

ii. Drinking Water For drinking water, acute EDWC exposure wil l be determined by modeling the total toxic reside of parent with E

- 1 noting that this short

- term exposure will be mainly associated with E

- 1 because parent is expected to degrade rather quickly (half

- life <1 day). In contrast, chronic EDWC exposure will b e determined by modeling the total toxic reside of parent with E

- 1, E

- 2, and E

- 3 noting that this long

- term exposure will be mainly associated with E

- 3 as it is the most persistent degradate (the terminal degradate). It is noted that the total toxic residu e approach can only be used if parent, E

- 1, E

- 2, and E

- 3 are of similar toxicity. Similarity in toxicity of E

- 1, E

- 2, and E

- 3 were assumed by the Metabolism Assessment Review Committee (MARC) 17



### . 

## b. Measures of Exposure
M easures of exposure of pyraflufen

- ethyl to the aquatic and terrestrial organisms are derived from the utilization of environmental fate and transport models

. For aquatic exposure EECs (surface water EECs) will be obtained by modeling using the total tox i c residue approach and t he Pesticide Root Zone Model coupled with the Exposure A nalysis Model System PRZM/EXAMS (PRZM v.3.12.2, May 2005 and EXAM S v.2.98.4.6, April2005 models coupled with the input shell PE5.pl, August, 2007) . The same models will be use d to estimate surface water EDWCs in addition to the PRZM

- GW model for ground water EDWCs. Al l of these models are available at EPA web site: http://www.epa.gov/oppefed1/models/water/ Exposures to aquatic and terrestrial organisms will be estimated based on maximum application rates and all application methods cited in Section 3

. The model used to predict terrestrial EECs on food items is T

- REX. The model to derive EECs relevant to terrestrial and wetland plants is TerrPlant. These models are parameterized using relevant reviewed registrant submitted environmental fate data. Exposure estimates for terrestrial animals assumed to be in the target area or in an area exposed to spray drift are deri ved using the T

- REX model (version 1. 5

. 2 , 06 / 20 /20 13 ). EECs for terrestrial plants inhabiting dry and wetland areas are derived using TerrPlant (version 1.2.2, 12/26/2006). This model uses estimates of pesticides in runoff and in spray drift to calculate EECs. EECs are based upon solubility, application rate and minimum incorporation depth. Additional information regarding these models can be found at: http://www.epa.gov/p esticides/science/models_pg.htm#terrestrial

17 PP#1F06248. Pyraflufen ethyl on Cotton and Potato. Outcome of Health Effects Division (HED) Metabolism Assessment Review Committee (MARC) Meeting Held July, 2002. PC Code 030090, DP Barcode: D284438.

### 29 i. Available Monitoring Data The Agency is not aware of monitoring conducted by federal and state agencies for this chemical as it is short

- lived in the environment. However, this route of exposure will be consid ered in the assessment to the extent that data on pyraflufen or any of its degradation products are available.



## c. Measures of Effect Toxicity data presented in Section 3 of this problem formulation will be used to calcu late risk quotients. Any additional information submitted by the registrant or found in the open literature prior to conduct of the risk assessment will also be considered. The open literature studies are identified using EPA’s ECOTOXicology database ( EC OTOX) ( USEPA, 2007 c ), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife. The evaluation of both sources of data can also provide insight into the direct and indirect effects of pesticides on biotic communities from loss of species that are sensitive to the chemical s and from changes in structure and functional characteristic s of the affected communities.


# 9. Endangered Species Assessments
Consistent with the Agency’s respons ibility under the Endangered Species Act (ESA), the Agency will evaluate risks to federally listed threatened and/or endangered (listed) species from registered uses of pesticides in registration review

. The process for evaluating potential risks to listed species is further described at http://www.epa.gov/oppfead1/endanger/litstatus/riskasses.htm

. 

# 10. Endocrine Disruptor Screening Program Pyraflufen

- ethyl was not included in the fir st group of 67 chemicals issued an order to conduct Tier 1 EDSP testing. For additional information the EDSP program, visit http://www.epa.gov/endo/
. 

# 11. Preliminary Identification of Data Gaps

a. Environmental Fate
Table 11 i dentif

ies environmental fate studies by MRID that offer data for each guideline requirement, as well as study classifications and whether or not further data are needed in order to support risk assessment

.

### 30

Table 11 Submitted Environmental Fate and Transport Data for Pyraflufen

- ethyl; noting that studies submitted for degradates are identified by the name of the degradate: E
- 1, E
- 2 or E
- 3 OCSPP Guideline Data Requirement Submitted Studies (MRID) Study Clas sifications 835.2120 Hydrolysis 452830

- 17 Acceptable 835.2120 Hydrolysis for E
- 1 452830

- 18 Acceptable 835.2240 Aqueous photolysis 453276

- 28 & 461627

- 02 Supplemental 835.2410 Soil photolysis 452830

- 19 Supplemental 835.4100 Aerobic soil metabolism 45283 0

- 20/21/22 Supplemental 835.4100 Aerobic soil metabolism for E
- 2 452830

- 23 Supplemental 835.4100 Aerobic soil metabolism for E
- 3 452830

- 24 Supplemental 835.4300 Aerobic aquatic metabolism 452830

- 25 Acceptable 835.4400 Anaerobic aquatic metabolism 45327 6

- 29 Acceptable 835.1230 835.1240 Adsorption/ desorption & leaching 452830

- 29 & 452830

- 26/28 Supplemental
835.1230 Adsorption/ desorption for E
- 1 452830

- 31 Supplemental 835.1230 Adsorption/ desorption for E
- 2 452830

- 32 Supplemental
835.1230 Adsorption/ desorption for E
- 3 452830

- 33 Supplemental
835.6100 Terrestrial field dissipation 452830

- 34/35 Acceptable 850

- 1730 Bio

- concentration in Fish for E
- 1 452828

- 03 Acceptable
850.6100 ECM & ILV* for soil
850.6100 ECM & ILV* for sediment
850.6100 ECM & IL V* for water A cursory review of the methods (MRIDs: 452830
- 08, 452830
- 07, 473687
- 02, 483812
- 02, and

452828
- 02) indicated that it is necessary to verify the following: (1) Which ECM is associated with which ILV; (2) What are the verified LODs and LOQs for each procedure; Noting that the chemical is expected to be at low concentrations in the environment and that LOQs for the residues of concern (parent, E

- 1, E

- 2 and E

- 3) are lower than the relevant toxicological levels of concern; (3) That there are ECMs/I LVs for water, soil and/or sediment (should specify/test if the method works for soil and sediment if that is the case; (4) ) The method is not affected by the fact that parent and E

- 3 elute at almost t he same time (6.5 and 6.6 min); a nd Finally , ECMs and ILVs should be for parent + E

- 1 + E

- 2 + E

- 3 for water and soil/sediment alone or in combination.

* ECMs= E nviro nmental Chemistry Methods & Associated ILVs= Independent Laboratory Validations (ILVs) 

### With the exception of ECMs and ILVs, a t this time no dat a gaps are identified noting that many of the studies are supplemental studies and reasons for such classification were clearly defined in the data evaluation reports (DERs). It might be possible to ask for additional data if new uses are requested with hi gher application rates. 

## b. Effects
Table 1 2 and Table 1 3 identify ecological effects studies by MRID that offer data for each guideline requirement for parent pyraflufen

- ethyl and the E

- 1 degradate in the aquatic medium , respectively , as well as study class ifications and whether or not further data are needed in order to

### 31

support risk assessment. Table 1 4 provides the previously mentioned information for parent pyraflufen

- ethyl studies conducted on terrestrial organisms. With respect to the submitted stu dies, there are a couple points to be made. First, 40 CFR Part 158 requires one waterfowl or one upland game species for an acute oral study and an acute oral study to passerines. Currently, there is only one acute oral study available for pyraflufen

- eth yl which is conducted on the mallard duck. The study was tested up to concentrations of 2000 mg a.i/kg

- bw with no mortalities or clinical signs of toxicity observed in the study. Similarly , in two available acute dietary studies with the mallard duck and northern bobwhite quail, birds were exposed to concentrations of pyraflufen

- ethyl in the diet up to 5000 mg a.i/kg

- diet. As in the acute oral study, there were no treatment related mortalities or clinical signs of toxicity observed. As discussed earlier in this assessment, pyraflufen

- ethyl has a generally herbicidal mode of action in and is applied at very low application rates (max seasonal rates do not exceed 0.018 lbs a.i/A). A n additional acute oral study with a passerine species would have to show increased toxicity by three orders of magnitude over the submitted study for the mallard duck to trigger an acute dose

based risk concern. Therefore, an additional avian acute oral study with a passerine species is not determined to have a substantial add ed value to the overall risk assessment of pyraflufen

- ethyl. Currently, only one chronic avian reproduction study is available for pyraflufen

- ethyl. One study with the northern bobwhite quail was submitted and found to be supplemental with no treatment r elated effects up to and including the highest concentration tested (4836 mg a.i/kg

- diet). Based on currently registered labels of pyraflufen

- ethyl, an additional chronic avian reproduction study would have to show effects at levels of approximately 4 mg a.i/kg

- diet, more than 3 orders of magnitude lower from where the northern bo bwhite study showed no effects

. D ue to the generally herbicidal mode of action of pyraflufen

- ethyl , the very low application rates of pyraflufen

- ethyl , and the results of the cur rent avian reproduction study indicating no treatment related effects, a n additional chronic avian reproduction study would not have a substantial added value to the overall risk assessment. The second point relates to the various degradates of pyraflufe n
- ethyl in the aquatic media. Currently, data are available for parent pyraflufen

- ethyl and the degradate E

- 1, which forms within 1

- 2 days in the aquatic systems. Available data indicate that parent pyraflufen

- ethyl is 2

- 3 orders of magnitude more toxic than E

- 1, depending on the taxa. As discussed previously in this assessment, E

- 1 further transforms to E

- 2, which itself along with E

- 1 , is a transient degradate. E

- 2 ultimately transforms to E

- 3 , for which, along with E

- 2, there are currently no toxicit y data available for. An analysis of the estimated toxicity of thedegradates was presented in Section 6 using the quantitative structure activity relationship (QSAR) tool ECOSAR (v.1.0). That analysis, while subject to the uncertainty inherent in estimat ing toxicity from a few data points, suggests that E

- 2, and E

- 3, while more toxic than E

- 1, are at least an order of magnitude less toxic than parent pyraflufen

- ethyl

. It’s also important to note from the discussion on transformation products earlier in the document that E

- 3 will ultimately form at concentrations that are substantially less than that of the total amount of pyraflufen

- ethyl applied. Concentrations of E

- 3 in aquatic systems can arise from two sources; from drift of the parent and from run

- off from soil. Residues of E

- 3 forming due to drift of the parent are expected to reach a maxi mum of 10% while formation of E

- 3 on soils reached a maximum of 50% (depending on the soil) that is available for runoff. To further characterize this,

### 32

PRZM/EX AMS was run for a scenario that represents the highest labeled rate of pyraflufen

- ethyl (0.00894 lbs a.i/A, 2 applications, 7

- day interval, ground application, potatoes). In modeling, parent, E

- 1, E

- 2, and E

- 3 were considered as one chemical and the most conservative parameters were chosen from among the three chemicals. The results of this exercise gave a chronic value of 0.77 ppb which is considered to be related to the terminal degradate E

- 3. In another words, the overall average of 0.77 ppb represents estimated E

- 3 concentrations in aquatic systems following the highest currently regis tered use of pyraflufen

- ethyl. While there is uncertainty in the ECOSAR estimates, the analysis presented earlier indicates toxicity anywhere from 2

- 4 orders of magnitude less toxic than this threshold

. Based on all of these lines of evidence, further toxicity data on the degradation products of pyraflufen

- ethyl are not determined to have substantial added value to the overall risk assessment.
Table 1 2
. Submitted Aquati c Ecological Effects Data for Pyraflufen

- ethyl

OCSPP Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Are data

needed to conduct risk assessment? Assumptions EPA will Make in Absence of Data

850.1010 Freshwater

invertebrate acut e toxicity 45282724 Acceptable No

45282713 Supplemental 850.1025 850.1035 850.1045 850.1055 Saltwater

invertebrate acute toxicity 45389203 Supplemental No

45389202 Supplemental

850.1075 Freshwater fish

acute toxicity 45282722 Acceptable

No

45282723 Acceptable 45327604 Supplemental 45282710 Supplemental 46641602 Supplemental
850.1075 Saltwater fish

acute toxicity 45389204 Supplemental No

850.1300 Freshwater

invertebrate life cycle 45389201 Acceptable No

850.1400 Freshw ater fish

early

- life stage 45389205 Supplemental No

850.1400 (modified) Freshwater fish

early

- life stage under high light conditions 48409701 Supplemental No

### 33

OCSPP Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Are data

needed to conduct risk assessment? Assumptions EPA will Make in Absence of Data

Non

- guideline (OECD 219) Spiked water

sediment test with freshwater midge 46641601 Supplementa l No

850.4400 Aquatic plant

Toxicity Test using Lemna spp. 45282728 Acceptable No

850.4500 Algal toxicity 45327606 Acceptable No 45282730 Supplemental 45282729 Acceptable 850.4550 Cyanobacteria 45282731 Acceptable No



### Table 1 3
. Aquatic E cological Effects Data for the Pyraflufen

- ethyl Degradate, E

- 1

OCSPP Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Are data

needed for risk assessment ? Current Additional Data Need

850.1075 Freshwater fish

acute toxicity 452827 12 Supplemental No

45282711 Supplemental No

45282718 Supplemental No

850.1010 Freshwater

invertebrate acute toxicity 45282715 Supplemental No

850.1300 Freshwater

invertebrate life cycle 45282720 Supplemental No

850.1400 Freshwater fish

earl y
- life stage 45282719 Supplemental No
850.1025 850.1035 850.1045 850.1055 Saltwater

invertebrate acute toxicity 45282717 Acceptable No

### 34

Table 1 4
. Submitted Terrestrial Ecological Effects Data for Pyraflufen

- ethyl

OCSPP Guideline Data

Requirement Submi tted

Studies (MRID) Study

Classifications Are data

needed for risk assessment? Assumptions EPA will Make in Absence of Data

850.2100 Avian oral

toxicity 45282704 Acceptable N o

850.2200 Avian dietary

toxicity 45282706 Acceptable No

45282707 Acceptabl e 850.2300 Avian

reproduction 45327603 Supplemental No

850.3020 Honey bee

acute contact toxicity 45282732 Acceptable No

Non

guideline Contact study

with Predacious Mite 45282801 Supplemental No

850.6200 Earthworm

subchronic toxicity test 45282733 Supplemental No

850.4100 Seedling

Emergence 45282725 Acceptable No

850.4150 Vegetative

Vigor 45282726 Acceptable No

Non

guideline Effect of

multiple applications on seedling growth 45282727 Supplemental No



# 12. References
Jones, R.D. et al., 2000. Guidance for use of the Index Reservoir and Percent Crop Area Factor in Drinking Water Assessments (March 21, 2000). Office of Pesticide Programs, Environmental Fate and Effects Division, U.S. Environmental Protection Agency. Arlington, VA.

### 35

USEPA. 1999. Guidance for Use of the Index Reservoir in Drinking Water Exposure Assessments. Arlington, VA. USEPA. 2000. Drinking Water Screening Level Assessment. Part A: Applying a Percent Crop Area Adjustment to Tier II Surface Water Model Estimates for Pest icide Drinking Water Exposure Assessments. FQPA Science Policy Document .Public Comment Draft September 1, 2000. Federal Register: October 11, 2000 (volume 65, number 197). Electronic copy available at http://www.epa.gov/pesticides/trac/science/ .
USEPA . 2002a. Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides, Version II (February 28, 2002). Office of Pesticide Programs, Environmental Fate and Effects Division, U.S. Environmental Protection Agency. Arlington, VA. U.S. EPA. 2002b. Pesticide Root Zone Model (PRZM) Field and Orchard Crop Scenarios: Standard Procedures for Conducting Quality Control and Quality Assurance. Office of Pesticide Programs, Environmental Fate and Effects Division, U.S. Enviro nmental Protection Agency. Arlington, VA. U.S. EPA. 2003b. Use of Regional Percent Crop Area Factors in Refined Drinking Water Assessments. US EPA Office of Pesticide Programs (OPP), Environmental Fate and Effects Division (EFED), Water Quality Technical Team (WQTT). Arlington, VA USEPA, 2003c. SCI

- GROW 2.3: Windows Version of SCI

- GROW. September 30, 2003. Office of Pesticide Programs, Environmental Fate and Effects Division, U.S. Environmental Protection Agency. Arlington, VA.
USEPA. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs . United States Environmental Protection Agency (USEPA). Environmental Fate and Effects Division. Office of Pesticide Programs. Available at http://www.epa.gov/espp/consultation/ec orisk

- overview.pdf

.

### 36



# Environmental Fate Studies

Hydrolysis 835.2120 (previously 161
- 1)

MRID Citation Reference

45283017 2010868 McKemie, T. (1999) Hydrolysis of (carbon 14) ET

- 751 at pH 5, 7, 9: Lab Project Number: 802W

- 1: 802W: E

- 5034. Unpublish ed study prepared by PTRL West, Inc. 107 p. 45283018 2010869 Lewis, C. (1997) (Carbon 14)

- E

- 1 Hydrolytic Stability: Lab Project Number: CHE 608/49: E

- 5024. Unpublished study prepared by Corning Hazleton (Europe). 60 p. 

### Photodegradation in Water 835. 2 240 (previously 161
- 2)

MRID Citation Reference

45327628 2010870

2048725

- revision Ikemoto, Y.; Shigemura, M.; Takahashi, Y. (1997) Aqueous Photolysis Study of

ET

- 751: Lab Project Number: LSRC

- E96

- 066A: E

- 5025. Unpublished study prepared by Nihon Nohyaku Co., Ltd., Research Center. 83 p.

46162702 2048724

2048725=

- revision Maks, M. (2003) Supplement 1: Aqueous Photolysis Study of ET/751. Project

Number: LSRC/E96/066A, E/5025, GC/03/96/0037. Unpublished study prepared by Nihon Nohyaku Co., Ltd. 14 p. 

### Photodegradation in Soil Guideline 835.2410 (previously 161
- 3)

MRID Citation Reference

45283019 2010871 Concha, M. (2000) Photodegradation of (carbon 14)ET

- 751 in/on Soil by Artificial Sunlight: Lab Project Number: 783W

- 1: 783W: E

- 5038. Unpub lished study prepared by PTRL West, Inc. 211 p.


### Aerobic Soil Metabolism Guideline 835.4100 (previously 162
- 1)

MRID Citation Reference

45283020 2010872 Shepler, K. (2000) Aerobic Soil Metabolism of (Carbon 14)ET

- 751: Lab Project Number: E

- 5036: 745W. Unpublished study prepared by PTRL West, Inc. 196 p.

### 37

45283021 2010873 Purser, D. (1995) (Carbon 14)ET

- 751: Soil Degradation at 20 (degrees)C: Lab Project Number: E

- 5001: 608/8

- 1015. Unpublished study prepared by Corning Hazleton (Europe). 112 p. 45283022 2010874 Purser, D. (1995) (Carbon 14)ET

- 751: Soil Degradation at 10 (degrees)C: Lab Project Number: E

- 5003: 608/9

- 1015. Unpublished study prepared by Corning Hazleton (Europe). 97 p. 45283023 2010876 Yeomans, P. (1996) (Carbon 14)

- E

- 2 (ET

- 751 Metabolite): Soil Degradation at 20 (degrees)C: Lab Project Number: E

- 5013: 608/12

- 1015. Unpublished study prepared by Corning Hazleton (Europe). 110 p. 45283024 2010877 Yeomans, P. (1996) (Carbon 14)

- E

- 3 (ET

- 751 Metabolite): Soil Degradation at 20 (deg rees)C: Final Report: Lab Project Number: E

- 5014: 608/13

- 1015. Unpublished study prepared by Corning Hazleton (Europe). 107 p. 

### Anaerobic Aquatic Metabolism Guideline 835.4400(previously 161
- 4)

MRID Citation Reference

45327629 2010878 Concha, M. (2000) Anaerobic Aquatic Metabolism of (carbon

- 14)ET

- 751: Lab Project Number: 781W

- 1: 781W: E

- 5037. Unpublished study prepared by PTRL West, Inc. 189 p. 

### Aerobic Aquatic Metabolism Guideline 835.4300 (previously 161
- 3)

MRID Citation Reference

4 5283025 2010879 Lewis, C. (1996) (Carbon 14)ET

- 751: Degradation and Retention in Water

Sediment Systems: Lab Project Number: E

- 5011: 608/23

- 1015. Unpublished study prepared by Corning Hazleton (Europe). 166 p. 

### Adsorption/Desorption (Batch Equilibrium) 8 35.1230 (old 163
- 1)

MRID Citation Reference

45283026 2010881 Kimura, Y. (1996) Soil Column Leaching of (Pyrazole

- 5(Carbon 14))ET

- 751: Lab Project Number: LSRC

- M96

- 007A: GC

- 04: 95

- 0047. Unpublished study prepared by Nihon Nohyaku Co., Ltd. 31 p. 45283027 2011135

Amend. Pg.6 Chisholm, K. (2000) E

- 5009: Addendum 1 to Report E

- 5009: Soil Column

Leaching of (Pyrazole

- 5(carbon 14))ET

- 751: Lab Project Number: E

- 5009. Unpublished study prepared by Nihon Nohyaku Co., Ltd. 12 p. 45283028 2011135 Kimura, Y. (1996) Soil Column Leaching of (Pyrazole

- 5(carbon 14))ET

- 751: Lab Project Number: LSRC

- M96

- 008A: GC

- 04: 95

- 0100. Unpublished study prepared by Nihon Nohyaku Co., Ltd. 30 p. 45283029 2011134 Yeomans, P. (1996) (Carbon 14)ET

- 751: Adsorption/Desorption i n Four Soils:

### 38 Final Report: Lab Project Number: 608/29

- 1015: E

- 5015. Unpublished study prepared by Corning Hazleton (Europe). 79 p. 45283030 2010880 Bates, M. (1996) ET

- 751: Determination of Adsorption Coefficient on Soil (Koc) HPLC Simulation: Final Rep ort: Lab Project Number: 608/34

- 1014: E

- 5005. Unpublished study prepared by Corning Hazleton (Europe). 20 p. 45283031 2010882 Yeomans, P. (1996) (Carbon 14)

- E

- 1 (ET

- 751 Metabolite): Adsorption/Desorption in Three Soils: Final Report: Lab Project Number: E

5016: 608/14

- 1015. Unpublished study prepared by Corning Hazleton (Europe). 91 p. 45283032 2010883 Yeomans, P. (1996) (Carbon 14)

- E

- 2 (ET

- 751 Metabolite): Adsorption/Desorption in Three Soils: Final Report: Lab Project Number: E

5017: 608/15

- 1015. Unpu blished study prepared by Corning Hazleton (Europe). 91 p. 45283033 2011136 Yeomans, P. (1996) (Carbon 14)

- E

- 3 (ET

- 751 Metabolite): Adsorption/Desorption in Three Soils: Lab Project Number: E

- 5017: 608/15

- 1015. Unpublished study prepared by Corning Hazle ton (Europe). 91 p. 

### Terrestrial Field Dissipation 835.6100 (previously 164
- 1)

MRID Citation Reference

45283008 2083970

Pg. 3 Benwell, L.; Burden, A. (1995) Analytical Procedure (CHE 608/26

- 02R) ET

- 751

and Its Metabolite E1,E2,E3: The Determinat ion of Residues in Soil: Lab Project Number: 608/26

- 1016A: A

- 5025. Unpublished study prepared by Covance Laboratories. 26 p. 45283034 2010884 Baker, F.; Estigoy, L.; Kimmel, E. (1996) Field Soil Dissipation of (Pyrazole

- 5 (carbon 14))ET

- 751 in Bare Groun d in California: Lab Project Number: E

- 5035: 737W. Unpublished study prepared by PTRL West, Inc. 92 p. 45283035 2010885 Baker, F.; Bautista, A.; Kimmel, E. (2000) Field Soil Dissipation of (Pyrazole

- 5

- (carbon 14))ET

- 751 in Bare Ground in Washington: Lab Project Number: 854W: 854W

- 1: E

- 5039. Unpublished study prepared by PTRL West, Inc. and Qualls Agricultural Laboratory. 318 p. 

### Confined rotational crop

MRID Citation Reference

45327627 Check with

HED Clarke, D. (1998) (Carbon

- 14)

- ET

- 751: A Conf ined Rotational Crop Study Using Radishes, Lettuces and Barley: Lab Project Number: 12170: R

- 5049: 201603. Unpublished study prepared by Rhone

- Poulenc Agriculture Limited. 192 p. {OPPTS 860.1850} 

### Fish Bioaccumulation 850.1730 (previously 72
- 6 and 165
- 4)

MRID Citation Reference

### 39

45282803 2010886 Grinell, A.; Croudace, C.; Caunter, J. et al. (1996) E

- 1: Determination of the Accumulation and Elimination of (carbon

- 14)E

- 1 in Rainbow Trout (Oncorhynchus mykiss): Lab Project Number: AB0831/H: W

- 5030: B L5605/B. Unpublished study prepared by Zeneca Ltd. 42 p.


### Non
- Guideline Study

MRID Citation Reference

45282703 Registrant

modeling Habig, C. (2000) Pyraflufen

- Ethyl: AgDrift Modeling to Assess Risk to

Aquatic and Terrestrial Plants from Spray D rift: Lab Project Number: ET

GEN

- 04. Unpublished study prepared by Nihon Nohyaku America, Inc. 18 p.

45283007 2083970

Pg 3 Anding, C. (1997) Analytical Method Validation of ET

- 751 and Its Metabolite

E

- 1 Water: Lab Project Number: RPA/96

- 061: AR 133

- 95: A

- 5027. Unpublished study prepared by Defitraces. 34 p.

45327601 Registrant

assessment Esterly, D. (2000) Comparison of Estimated Environmental Exposures for

Pyraflufen

- Ethyl with Alternative Chemicals: Lab Project Number: ET

- GEN

03. Unpublished study pre pared by Environmental Focus, Inc. 42 p.

47368702 Not located O'Connor, B.; Atwal, S.; Woolley, S. (2008) NNH

- 950

- 4: Analytical Method Validation . Project Number: 0199/0324. Unpublished study prepared by Safepharm Laboratories, Ltd. 64 p.

48381202 Not located Jones, S. (2008) To Conduct a Validation of the Analytical Method Pyraflufen E1/Water/SJ/08/1 for the Analysis of Pyraflufen E1 in Water: Final Report. Project Number: A/5062. Unpublished study prepared by Eurofins

- Agrisearch Americas, Inc. 65 p.

45282802 2010875 Dengler, D. 1997. Assessment of the side effects of ET

- 75 1 technical on the activity of the soil microflora. Unpublished study performed by Arbeitsgemeinschail, GAB Biotechnologie GmbH & IFU Umweltanalytik GmbH, Hiefern

- 0scheo Germany an d submitted by Nihon Nohyaku Co. Ltd., Tokyo, Japan. Study code and Report No.: 95 1 80/0 1

- ABMF. Study initiated (experimental phase) February 3, 1997 and final report issued April 2,1997. Request for review Analytical Procedure (CHE 608/26

- 02R) ET

- 75 1 and Its Metabolites El, E2, E3: The Determination of Residues in Soil


# Ecological Effects Studies
Avian Acute Oral Toxicity Test Guideline 850.2100 (previously 71
- 1)

MRID Citation Reference

45282704 2011161 van Dreumel, I.; Leopold, M. (1995) Acute Oral Toxicity Data on Bobwhite Quail(Pyraflufen

- Ethyl): Lab Project Number: 144945: 50427: W

- 5010.

### 40 Unpublished study prepared by NOTOX B.V. 39 p. 

### Avian Dietary Toxicity Guideline 850.2200 (previously 71
- 2)

MRID Citation Reference

45282 706 2011160 van Druemel, I.; Leopold, M. (1995) 5

- Day Dietary Toxicity Study in Mallard Duck with ET

- 751 Technical: Lab Project Number: 153045: 50427: W

- 5011. Unpublished study prepared by NOTOX B.V. 82 p. 45282707 2011159 van Druemel, I.; Reijnders, J ( 1996) 5

- Day Dietary Toxicity Study in Bobwhite Quail with ET

- 751 Technical: Lab Project Number: 146824: 50427: W

- 5019. Unpublished study prepared by NOTOX B.V. 76 p. 

### Avian Reproduction Guideline 850.2300 (previously 71
- 4)

MRID Citation Reference

45282709 2011148 Stadens

- Peek, W.; Leopold, M. (1997) Reproduction Study in Mallard Duck with ET

- 751 Technical: Lab Project Number: 157242: 50427: W

- 5032. Unpublished study prepared by NOTOX B.V. 157 p. 45327602 2052183

pilot study Leopold, M. (1997) 6

- Weeks Dietary Study in Mallard Duck with ET

- 751

Techn. (Pilot Dietary Study for Reproduction Study): Lab Project Number: 157253: 50427: W

- 5033. Unpublished study prepared by NOTOX B.V. 27 p. 45327603 2011141 Frieling, W. (2000) Reproduction Study in Bo bwhite Quail with Pyraflufen

Ethyl Technical (By Dietary Admixture): Lab Project Number: 265062: 89397: W

- 5052. Unpublished study prepared by NOTOX B.V. 196 p. {OPPTS 850.2300} 46447901 Supplement

1 to MRID # 45282709 Maks, M. (2004) Supplement 1 to: Re production Study in Mallard Duck with

ET

- 751 Technical. Project Number: 157242, 50427, W/5032. Unpublished study prepared by Notox B.V. 39 p.


### A cute Toxicity to Freshwater Fish Guideline 850
- 1075 (previously 72
- 1)

MRID Citation Reference

45282710 2011167 Caunter, J.; Magor, S.; Croudace, C. (1995) ET

- 751: Acute Toxicity to Rainbow Trout: Lab Project Number: BL5511: W

- 5003. Unpublished study prepared by Zeneca Limited. 18 p. 45282711 2011151 Caunter, J.; Johnson, P.; Croudace, C. (1995) E

- 1: Acut e Toxicity to Rainbow Trout: Lab Project Number: W

- 5017: BL5601. Unpublished study prepared by Zeneca Limited. 19 p. 45282712 2011144 Caunter, J.; Cornish, S.; Croudace, C. (1995) E

- 1: Acute Toxicity to Bluegill Sunfish: Lab Project Number: W

- 5018: BL560 2. Unpublished study prepared by Zeneca Limited. 19 p.

### 41

45282715 2011173 Croudace, C.; Banner, A.; Johnson, P. (1995) E

- 1: Acute Toxicity to Daphnia magna: Lab Project Number: BL5600: W

- 5016: AB0831/C. Unpublished study prepared by Pharmaco LSR Ltd. 18 p. 45282722 2011145 Sousa, J. (2000) ET

- 751 2.5% EC(N) Acute Toxicity to Bluegill Sunfish (Lepomis macrochirus) Under Flow

- Through Conditions: Lab Project Number: 13657.6125: W

- 5046. Unpublished study prepared by Springborn Laboratories, Inc. 78 p. {OPPTS 850.1075} 45282723 2011146 Sousa, J. (2000) ET

- 751 2.5% EC(N) Acute Toxicity to Rainbow Trout (Oncorhynchus mykiss) Under Flow

- Through Conditions: Lab Project Number: 13657.6124: W

- 5050. Unpublished study prepared by Springborn Laboratories, Inc. 78 p. { OPPTS 850.1075} 45327604 2011166 Moore, K.; Caunter, J.; Shearing, J. (1999) ET

- 751: Determination of Acute Toxicity to Bluegill Sunfish (Lepomis macrochirus): Lab Project Number: BL6592/B: AG0225/A: W

- 5042. Unpublished study prepared by Zeneca Ltd. 19 p
. 46641602 2052183

Contractor Draft Palmer, S.; Kendall, T.; Krueger, H. (2004) A 96

- Hour Flow

- Through Acute

Toxicity Test with the Rainbow Trout (Onchorhynchus mykiss): Final Report. Project Number: 397A/102. Unpublished study prepared by Wildlife Inter national, Ltd. 41 p. with 2% active ingredient 

### Acute Toxicity to Freshwater Invertebrates Guideline 850
- 1010 or 850
- 1020 (previously 72
- 2)

MRID Citation Reference

45282713 2011163 Banner, A.; Johnson, P.; Croudace, C. (1995) ET

- 751: Acute Toxici ty to Daphnia

magna: Lab Project Number: BL5510: W

- 5020. Unpublished study prepared by Zeneca Limited. 20 p. 45282715 2011173 Croudace, C.; Banner, A.; Johnson, P. (1995) E

- 1: Acute Toxicity to Daphnia

magna: Lab Project Number: BL5600: W

- 5016: AB0831/C. Unpublished study prepared by Pharmaco LSR Ltd. 18 p. 45282724 2011143 Cafarella, M. (2000) ET

- 751 2.5% EC(N) Acute Toxicity to Water Fleas,

(Daphnia magna) Under Flow

- Through Conditions: Lab Project Number: W

- 5047: 13657.6123. Unpublished study prepared by Springborn Laboratories, Inc. 78 p. {OPPTS 850.1010} 

### Acute Toxicity to Estuarine/Marine Crustacean Guidelines 850
- 1035 or 850.1045 (previously 72
- 3)

MRID Citation Reference

45282717 2011155 Cafarella, M. (2000) E

- 1 Acute Toxicity to Mysids (Mysidopsis bahia) Under

Static Conditions: Lab Project Number: 13657. 6129: W

- 5048. Unpublished study prepared by Springborn Laboratories, Inc. 56 p. 45389203 2011174 Putt, A. (2001) ET

- 751

-- Acute Toxicity to Mysids (Americamysis bahia) Under

Flow

- Throu gh Conditions: Lab Project Number: 13657.6147: W

- 5053.

### 42 Unpublished study prepared by Springborn Labs., Inc. 69 p. {OPPTS 850.1035} 

### Acute Toxicity to Marine Estuarine Fish Guideline 850
- 1075 (previously 72
- 3)

MRID Citation Reference

45282718 20 11154 Cafarella, M. (2000) E

- 1 Acute Toxicity to Sheepshead Minnow (Cyprinodon

variegatus) Under Static Conditions: Lab Project Number: 13657.6127: W

- 5049. Unpublished study prepared by Springborn Laboratories, Inc. 51 p.

45389204 2011162 Sousa, J. (200 1) ET

- 751

-- Acute Toxicity to Sheepshead Minnow (Cyprinodon

variegatus) Under Flow

- Through Conditions: Lab Project Number: 13657.6145: W

- 5054. Unpublished study prepared by Springborn Labs., Inc. 69 p. {OPPTS 850.1075} 

### Acute Toxicity to Estuarine/Marine Mollusc Shell Deposition Guideline 850.1025 (previously 72
- 3)

MRID Citation Reference

45327605 2011153 Dionne, E. (2000) E

- 1

- Acute Toxicity to Eastern Oysters (Crassostrea virginica)

Under Static (Recirculated) Conditions: Lab Project Number: 136 57.6128: W

5051. Unpublished study prepared by Springborn Laboratories. 57 p. {OPPTS 850.1025}

45389202 2011175 Dionne, E. (2000) ET

- 751

-- Acute Toxicity to Eastern Oysters (Crassostrea

virginica) Under Flow

- Through Conditions: Lab Project Number: 13657. 6146: W

5055. Unpublished study prepared by Springborn Labs., Inc. 72 p. {OPPTS 850.1025} 

### Fish Early Life Stage (Freshwater or Marine) Guideline 850.1400 (previously 72
- 4)

MRID Citation Reference

45282719 2011156 Croudace, C.; Caunter, J.; Wall ace, S. (1996) E

- 1 Chronic Toxicity to Fathead

Minnow (Pimephales promelas) Embryos and Larvae: Lab Project Number: W

5029: BL5604: AB0831/G. Unpublished study prepared by Zeneca Limited. 61 p. 45389205 2011164 Sousa, J. (2001) ET

- 751

-- The Toxicity to Fa thead Minnow (Pimephales promelas)

During an Early Life

- Stage Exposure: Lab Project Number: W

- 5059: 13657.6148. Unpublished study prepared by Springborn Labs., Inc. 91 p. 48409701 2086483 York, D. (2011) Pyraflufen

- Ethyl

- Early Life

- Stage Toxicity Test with Fathead

Minnow (Pimephales promelas) Under High Light Conditions: Final Report. Project Number: 13971/6101, TK0001570. Unpublished study prepared by Smithers Viscient Laboratories. 93 p. 48409701 Delete York, D. (2011) Pyraflufen

- Ethyl

- E arly Life

- Stage Toxicity Test with Fathead

### 43 duplicate Minnow (Pimephales promelas) Under High Light Conditions: Final Report.

Project Number: 13971/6101, TK0001570. Unpublished study prepared by Smithers Viscient Laboratories. 93 p. 

### Freshwater Aquatic Invertebrate Life Cycle Study Guideline 850.1500 (previously 72
- 4)

MRID Citation Reference

45282720 2011152 Croudace, C.; Williams, N.; Shearing, J. (1996) E

- 1 Chronic Toxicity to Daphnia

magna: Lab Project Number: W

- 5026: BL5603/B: AB0831/F. Unpublished study prepared by Zeneca Limited. 27 p.

45389201 2011165 Cafarella, M. (2000) ET

- 751

-- Full Life Cycle Toxicity Test with Water Fleas,

Daphnia magna Under Flow

- Through Conditions: Lab Project Number: W

- 5058: 13657.6149. Unpublished study prepared by Springbor n Labs., Inc. 101 p. {OPPTS 850.1300} 

### Tier I Seedling Emergence (single dosage test) Guideline 850.4100 (previously 122
- 1)

MRID Citation Reference

45282725 2011149 Teixeira, D. (2000) ET

- 751 2.5%

- EC Determination of Effects on Seedling

Emergen ce of Ten Plant Species: Lab Project Number: 13657.6119: N

- 5021. Unpublished study prepared by Springborn Laboratories, Inc. 176 p. {OPPTS 850.4100 and 850.4225} 

### Tier I Vegetative Vigor (single dosage test) Guideline 850.4150 (previously 122
- 1)

MRID Citation Reference

45282726 2011150 Teixeira, D. (2000) ET

- 751 2.5% EC(N) Determination of Effects on Vegetative

Vigor of Ten Plant Species: Lab Project Number: 13657.6120: N

- 5014. Unpublished study prepared by Springborn Laboratories, Inc. 162 p. { OPPTS 850.4150, 850.4250} 

### Algal Plant Toxicity Test Tiers I and/or II Guideline 850.5400 (previously 123
- 2)

MRID Citation Reference

45282729 2011172 Hoberg, J. (2000) ET

- 751 2.5% EC(N) Acute Toxicity to the Freshwater Diatom

(Navicula pel liculosa): Lab Project Number: N

- 5025: 13657.6117. Unpublished

### 44 study prepared by Springborn Laboratories, Inc. 70 p. {OPPTS 850.5400} 45282730 2011171 Hoberg, J. (2000) ET

- 751 2.5% EC(N) Acute Toxicity to the Marine Diatom,

Skeletonema costatum: Lab Proj ect Number: 13657.6118: N

- 5023. Unpublished study prepared by Springborn Laboratories, Inc. 69 p. {OPPTS 850.5400} 45282731 2011168 Hoberg, J. (2000) ET

- 751 2.5% EC(N) Acute Toxicity to the Freshwater Blue

Green Alga (Anabaena flos

- aquae): Lab Project Nu mber: 13657.6115: N

- 5022. Unpublished study prepared by Springborn Laboratories, Inc. 69 p. {OPPTS 850.5400} 45327606 2011170 Hoberg, J. (2000) ET

- 751 2.5% EC(N)

- Acute Toxicity to the Freshwater Green

Alga (Pseudokirchneriella subcapitata): Lab Project Number: 13657.6116: N

5024. Unpublished study prepared by Springborn Laboratories, Inc. 69 p. 

### Aquatic Plant Toxicity Test using Lemna spp. Tiers I and II Guideline 850.4400 (previously 123
- 2)

MRID Citation Reference

45282728 2011169 Hoberg, J. (2000) ET

- 751 2.5% EC Toxicity to Duckweed, Lemna gibba: Lab

Project Number: 13657.6114: N

- 5026. Unpublished study prepared by Springborn Laboratories, Inc. 77 p. {OPPTS 850.4400} 

### Tier II Seedling emergence Guideline 850.4150 (previously 123
- 1)

MRI D Citation Reference

45282725 2011149 Teixeira, D. (2000) ET

- 751 2.5%

- EC Determination of Effects on Seedling Emergence of Ten Plant Species: Lab Project Number: 13657.6119: N

- 5021. Unpublished study prepared by Springborn Laboratories, Inc. 176 p . {OPPTS 850.4100 and 850.4225}

45282727 2011142 Teixeira, D. (2000) ET

- 751 2.5% EC(N) Determination of Effects on Multiple Applications on Early Seedling Growth of Ten Plant Species: Lab Project Number: 13657.6121: N

- 5013. Unpublished study prepared by Springborn Laboratories, Inc. 335 p. {OPPTS 850.4230} 

### Tier II Vegetative vigor Guideline 850.4250 (previously 123
- 1)

MRID Citation Reference

45282726 2011150 Teixeira, D. (2000) ET

- 751 2.5% EC(N) Determination of Effects on Vegetative Vigor of Ten Plant Species: Lab Project Number: 13657.6120: N

- 5014. Unpublished study prepared by Springborn Laboratories, Inc. 162 p. {OPPTS 850.4150, 850.4250}

### 45

Honey bee acute contact Guideline 850.3020 (previously 141
- 1)

MRID Citation Reference

45282732 2011157 Nengel, S. (1996) Assessment of Side Effects of ET

- 751 Technical to the Honey Bee, Apis mellifera L. in the Laboratory Following the EPPO Guideline No.170: Lab Project Number: 95180/01

- BLEU: N

- 5010. Unpublished study prepared by GAB B iotechnologie GmbH & IFU Umweltanalytik GmbH. 23 p. 

### Chironomid Sediment Toxicity Test Guideline 850.1790 (no previous FIFRA guideline) MRID Citation Reference

46641601 2052184 Odin

- Feurtet, M. (1998) ET

- 751 Toxicity to the Sediment Dwelling Chron omid

Larvae = 28 Days

- (Chiromus riparius). Project Number: SA/97497, W/5037. Unpublished study prepared by Rhone

- Poulenc Agrochemie. 89 p. 47635001 2052184

supple

mental Brooks, M. (2008) Supplement 1: ET

- 751 Toxicity to the Sediment Dwelling

Chironomid L arvae
- 28 Days (Chironomus riparius). Project Number: SA/97497, W/5037, T/5064SUPPLEMENT/1. Unpublished study prepared by Rhone

- Poulenc

- Secteur Agro. 24 p.


### Beneficial Insects 850.3000 Series 143
- 1 Toxicity to Predator and Parasite Insects

MRID Citatio n Reference

45282801 2011147 Nienstedt, K. (2000) ET

- 751 2.5% EC(N): Laboratory Contact Toxicity Test with the Predacious Mite, Typhlodromus pyri Scheuten (Acari: Phytoseiidae): Final Report: Lab Project Number: N

- 5015: 1012.002.268. Unpublished stu dy prepared by Springborn Labs., (Europe) AG. 25 p. 

### Earthworm Toxicity

MRID Citation Reference

45282733 2011158 Wachter, S. (1996) Acute Toxicity ET

- 751 Technical on Earthworms, Eisenia foetida Using an Artificial Soil Test: Lab Project Number: 95180/01

- NLEF. Unpublished study prepared by GAB Biotechnologie GmbH & IFU Umweltanalytik GmbH. 21 p.

### 46 

## Appendix 1: Labeled use patterns for pyraflufen
- ethyl

Use Pattern Application Parameters Single (lb. a.i./A) No. of

Applications Yearly

(lb. a.i./A) Min Intervals

(days) Method* Turf lawns (residential, industrial, and institutional), parks, cemeteries, athletic fields, golf courses (fairways, aprons, tees, and roughs), sod farms, and similar turf areas 0.00463 ? ? ? G Cotton (pre

- plant burn

- down) 0.00325 1 0.00325 N/A G, A Cotton (post

- emergence weed control) 0.00325 1 0.00325 30 G Cotton (post

- emergence layby) 0.00163 1 0.00163 30 G Cotton (cotton defoliation) 0.00447 2 0.00894 7 G, A

Cotton, combined uses (do not exceed this overa ll rate) ca. 5 0.01381 7 to 30 G & A Corn (pre

- plant burn

- down) 0.00325 1 0.00325 30 G, A Corn (post

- emergence, except sweet corn) 0.00122 2 0.00163 30 G, A

Corn, combined uses (do not exceed this overall rate) ? ? 30 G & A Deciduous fruit and nut tree s and vines (dormant, pre

- bloom, in season, and postharvest applications) (including pome fruits, stone fruits, and tree nuts) 0.00325 3 0.00894 30 B&BD Tree Nut Crop Group 14 (bearing & non

- bearing: post

- harvest, dormant, pre

- bloom, or in

- season applicat ion) 0.00528 3 or 2 ** 0.00894 30 G Non

- bearing tree fruit, nut and vine crops 0.00325 3 0.00894 30 NS Grapes

– bearing and non

- bearing (postharvest, dormant, pre

bloom, & in

- season) 0.00528 3 or 2 1 0.00894 30 G Stone Fruit Crop Group 12

– bearing & no n
- bearing trees (postharvest, dormant, pre

- bloom, & in

- season) 0.00528 3 or 2 ** 0.00894 30 G Pome Fruit Crop Group 11

– bearing & non

- bearing trees (postharvest, dormant, pre

- bloom, & in

- season) 0.00528 3 or 2 ** 0.00894 30 G Olives

– bearing & non

- bear ing trees (postharvest, dormant, pre

bloom, & in

- season) 0.00528 3 or 2 ** 0.00894 30 G Pomegranates

– bearing& non

- bearing (postharvest, dormant, pre

bloom, & in

- season) 0.00528 3 or 2 ** 0.00894 30 G Hops

– bearing& non

- bearing (postharvest, dormant, & in

season)

– Old ET 2.5% formulation registration 0.00528 3 0.00894 30 G Hops

– bearing& non

- bearing (postharvest, dormant, & in

season)

- New ET 2% SC formulation registration 0.00531 3 0.00903 40 G Pre

- plant fallow beds and crop stubble 0.00325 3 0.0 0894 30 NS Non

- crop land and uncultivated areas, Conservation Reserve Programs (CRP) and set

- aside acreage 0.00325 3 0.00894 30 G, A Non

- crop weed control (airports, commercial plants, storage and lumber yards, barrier strips and firebreaks, equipment ar eas, nurseries and ornamental plantings, sod farms) 0.00447 3 0.01594 NS G Peanuts (pre

- plant burn

- down) 0.00325 NS 0.00325 NS G

### 47 Use Pattern Application Parameters Single (lb. a.i./A) No. of

Applications Yearly

(lb. a.i./A) Min Intervals

(days) Method* Peanuts (after planting before crop emergence) 0.00325 NS 0.00325 NS G Peanuts (post

- emergence) 0.00325 ? 0.00625 30 G Pean uts, combined uses (do not exceed this overall rate) 0.00325 2 0.00625 30 G Pasture and rangeland 0.00366 2 0.00894 14 G, A Potato desiccation 0.00894 2 0.01789 7 G Root and tuber veg. (CG1), leafy veg. (CG4), cole crops (CG5), legumes (CG6), fruiting v eg. (CG8), cucurbits (CG9), oil seed crops (CG20), sugarcane, and cereal grains (CG15)

– All limited to pre

- plant burn

- down 0.00325 3 0.00894 30 G Soybeans (pre

- plant burn

- down) 0.00325 1 0.00325 30 G, A Soybeans (post

- emergence) 0.00122 2 0.00163 30 G, A

Soybeans, combined uses (do not exceed this overall rate) Wheat (pre

- plant burn

- down) 0.00163 2 0.00325 30 G, A Wheat (post

- emergence) 0.00163 1 0.00163 30 G, A Wheat, combined uses (do not exceed this overall rate) 0.00163 ? ? 30 * G= Ground, A= Aerial and B&BD= Broadcast & band directed application ** 2 applications per season allowed for “in

- season” application, 3 applications are allowed for other types of applications. NS = Not specified; ? = unknown (Need registrant to clarify by providing t he correct information in the label) ; In previous modeling a value was assumed. For example: in turf, it was assumed that the number of applications= 2 and the interval betwee n 7

- 14 days. The registrant is requested to clarify the label language and give t he correct values.

### 48



## Appendix 2: Parent, Major and Minor Degradates of Pyraflufen
- ethyl (1) Parent Common name: Pyraflufen

- ethyl. IUPAC Chemical name : ethyl 2

- [2

- chloro

- 5

- [4

- chloro

- 5

- (difluoromethoxy)

- 1

- methylpyrazol

3

- yl]

- 4

- fluorophenoxy] acetate


### CAS No: 129630

- 19

- 9. SMILES string ( Canonical SMILES) 

### : CCOC(=O)COC1=C(C=C(C(=C1)C2=NN(C(=C2Cl)OC(F)F)C)F)Cl 

### Molecular Weight: 413.2 g/mol

(2) Major Degradates E
- 1 Common name: E

- 1 (transformation product of pyraflufen

- ethyl) Or Pyraflufen IUPAC Chemical name: 2

- [2

- chloro

- 5

- [4

- chloro

- 5

- (difluoromethoxy)

- 1

- methylpyrazol

- 3

- yl]

- 4

- fluorophenoxy]acetic acid 

### CAS No: 129630

- 17

- 7 

### SMILES string: CN1C(=C(C(=N1)C2=CC(=C(C=C2F)Cl)OCC(=O)O)Cl)OC(F)F 

### Molecular Weight: 385 g/mol

### 49

E
- 2 Common name: E

- 2 Chemical name: IUPAC Chemical name: 2

- chloro

- 5

- [4

- chl oro - 5

- (difluoromethoxy)

- 1

- methylpyrazol

- 3

- yl]

- 4

- fluorophenol 

### CAS No: Not reported SMILES string: CN1C(=C(C(=N1)C2=CC(=C(C=C2F)Cl)O)Cl)OC(F)F 

### Molecular Weight: 327 .1 g/mol

E
- 3 Common name: E

- 3 IUPAC Chemical name: 4

- chloro

- 3

- (4

- chloro

- 2

- fluoro

- 5

- methoxyphenyl)

- 5

- (difluoromethoxy)

- 1

- methylpyrazole 

### CAS No: Not reported SMILES str ing: CN1C(=C(C(=N1)C2=CC(=C(C=C2F)Cl)OC)Cl)OC(F)F 

### Molecular Weight: 341 g/mol

### 50

PD
- 1 PD
- 1 (A major photolysis degradate ) C1(=CCC(=C(C=C1F)O[H])OCC(=O)OCC)C2=N[N](C(=C2Cl)OC(F)F)C

Major degradates Forms as follows:

CH 3 

### OH = E1 degradate All OH = E
- 2 Degradate
OR If All Cleaves Away

E
- 3 Degradate All Cleaves Away E
- 3 Degradate

### 51

(3) Minor Degradates of pyraflufen
- ethyl Name IUPAC Name Structure

E
- 8 Ethyl 2

- chloro

- 5

- (4

- chloro

- 5

- difluoromethoxy

- 1H

pyrazol

- 3

- yl)

- 4

- fluorophenoxyacetate

E
- 9 2

- Chloro

- 5

- (4

- chloro

- 5

- difluoromethoxy

- 1

- H

- pyrazol

- 3

- yl)

- 4

- fluorophenoxyacetic acid

E
- 10 2

- Chloro

- 5

- [4

- chloro

- 5

- difluoromethoxy

- 1 H

- pyrazol

- 3

-

yl]

- 4

- fluorophenol

E
- 11 4

- Chloro

- 3

- (4

- chloro

- 2

- fluro

- 5

- methoxyphenyl)

- 5

-

difluoro

- methoxy

- 1H

- pyrazole

U
- 1 2

- Fluoro

- 5

- hydroxy

- 5

- (N

- methylcarbamoyl)

- 4

- oxo
- pent

2

- enoic acid

U
- 1 A 2

- Fluoro

- 5

- hydroxy

- 5

- (N

- carbamoyl)

- 4

- oxo
- pent

- 2

- enoic

acid)