&,?ED 4374% 

IIlWTED STATES ENVWONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

OFFICE OF PJEWNEWM9PES~ESE~ TOXIC SUBSTANCES 

Memorandum 

PC Code 108853 

DP Barcode D270231 

D284046 

Date September 11,2003 

SUBJECT: New Chemical Review - Environmental Risk Assessment for the Proposed Uses 

of Flufen~vr Ethyl on Sugarcane and Soybeans. 

FROM: Steve Carey, Biologist 

~huy Wguyen, chemist c$ v-3 

Environmental Risk Branch III 

THRU: Ben SmQ Branch Chief 

Stephanie Syslo, RAPL 

Dr. W- Erichn, Biologist 

Environmental Risk Branch IIIEFED 

TO: Dime Morgan, Review Manager 

Joanne Miller, PM 23 

Herbicide Branch 

Registration Division 

TEs memorandum tmmmrhm the Environmental Pate and Effect Division's New 

Chernical Environmental Risk Assessment of flufenpyr ethyl herbicide to control post emergence 

broadleaf weeds on sugarcane, soybean, and field corn (excluding popcorn and sweet corn). The 

purpose of this review is to assess the environmental fate, potential ecological effects and 

potential drhking water concentrations associated with flufenpyr-ethyl. Concerns and suggestions 

for product labeling7 possible data gaps, and uncertainties are included in the review. 

Flufenpyr ethyl is a new herbicide produced by Sumitomo Chemical Company Ltd. and 

under development in the United States by Valent U.S.A. Corporation. As a contact herbicide, 

flufenpyr ethyl control susceptible weeds though disruption of the cell membrane and also 

induces the inhibition of protoporphyringen oxidase in the chlorophyll biosynthetic pathway and 

leads to a phytotoxic buildup of intermediates. Valent USA Corporation is seeking registration of 

S-3 1 53 WDG Herbicide (57.6% ai) for use on soybean and sugarcane and S-3 153lAtrazke 

WDG (1 -9 % a.i) for use sugarcane and andld corn. This is the &st application for a US 

registration of products containing fhfenpyr ethyL 
The proposed new uses considered for this herbicide are listed in the followiug table: 

Since data were not submitted on the formulation with Akcazine. this risk assessment 

focuses exclusively on the effects of flufqyr ethyl. Furthermore, althouh both labels are 

presented here, this assessment will be based only on the S-3 153-WDG formulation. 

Major Risk Conchsions 

Laboratory tests show that flufenpyr-ethyl is practically non-toxic to birds, mammils, and 

bees, but is moderately toxic to fieshwater fish and to estuariudmarine invertebrates on an acute 

basis. However, acute toxicity of flzrfenpyr-ethyl to 5-eshwakr invertebrates and estuarinetmarine 

iish was not seen at the solu~ lirnit in aquatic environments. At the chronic level, reproductive 

effects were identified in birds and fieshwater invertebrates vvhile growth effects were identified in 

fieshwater fish. Nevertheless, at the proposed use rates, the estimated environmental 

concentrations of flufenpy-ethyl exposure did not trigger any Level of Concern exceedance for 

risks to birds &OC = I), aquatic organisms (LO@ = 0.05), or aquatic plants (LOC = 1). 

Based on the highest proposed single application rate (0.027 lb ai/A for S-3 153-WDG), 

EFED concludes that the only concern is for post-emergence terrestrial plants growing in areas 

adjacent to the treated sites that may be exposed by spray drift (based on drift LOC exceedances 

fi-om ground and aerial applications). The results of EFED9s Tier I TerrPlant model suggest . . ground application under conditions that mbmize drift is preferable to aerial application. Levels 

of concern were not exceeded for non target terrestrial plants exposed to m off. 

The f& and disposition of flufq etby1 and its major degradates combined with the 

EFED water models results indicate that there is a very low probability for either flupenfyr ethyl 

andlor its degradates to reach ground or sd&ce water at any significant level. 

Data Requirements 

The environmental fhte and ecological database for flufi:npyr-ethyl is largely complete for 
an adequate risk assessment. However, note the following: 

123-l(a) Seedling Emergenee: The parent iluhpyr--ethyl degrades rapidly in the soil, yet weed 

control is provided for a longer duration. Although no terratrial plant toxicity data were provided 

for the degradates, the S-1353-acid degradate, which is shown in laboratory studies to be more 

toxic to aquatic vascular plants than the parent compound, could also be more toxic to terrestrial 

plants and the cause of this residual ei%ct. In addition, literature and past incidences of other 

herbicides reported the potential for possible damage to terrestrial plants from contaminated 

surface waters with phytotoxic compounds. Based on the above stated reasons, and since the 

parent RQs border on the LOC for risk to non-targ& or endangered plants fiom combination of 

drift and mo@ possible risks hm the dewdate may be posed to terrestrial plants and/or 

irrigated crops via m oE Therefore, EFED recommends Tier I1 Seedling Emergence Toxicity 

testing for the S-1353-acid degradate to determine the toxicity to terrestrial plants, to better 

characterize runoff to non-target plants, and to determine risks to irrigated crops from 

contaminated sllrf$ce waters. The value added of repeating this study is "high". 

E23-$(b) Vegetative Vigor: Flufenpy-ethyl exhibits more toxicity fiom foliar uptake than stem 

or root uptake. Since spray drift is the major route of surfkce water contamination by parent 

fluhpyrethy1, and since this chemical will Begrade rapidly upon contact with soils, terrestrial 

plants in sites adjacent to treated areas could be exposed to the degradates, which are formed in 

soils following a spray drift event. For these reasons, additional risks may be posed to non-target 

plants and irrigated crops. EFED recommends Tier I1 Vegetative Vigor Toxicity Test for the S1353-acid degradate to determine the toxicity to terrestrial plants, to better characterize spray 

drift to non-target plants, and to determine risks to irrigated crops earn contaminated surface 

waters. The value added of repeating this study is '%$hB. 

Endangered Species 

The Agency's level of concern for non-target and endangered terrestrial plants is exceeded 

for the proposed use of flufenpy-ethyl on sugarcane, soybeans, and field corn. concern to 

terrestrial plants is based on spray drift to adjacent sites. As discussed m the summary of the risk 

assessment, restrictions on spray drii practices would help alleviate some of those concerns. 

However, they can not be totally addressed without eliminating aerial application Consequently, 

it will be important to assess the proximity of endangered plants to use areas. 

This requirement may be satisfied m one of three ways: 1) having membership in the 

FIFRA Endangered Species Task Force (Pesticide Registration PR] Notice 2000-2); 2) citing 

FIFRA Endangered Species Task Force data; or 3) independently producing these data, pyovided 

the information is of sufficient quality to meet FIFRA requirements. The information will be used 

by the OPP Endangered Species Protection Program to develop recommendations to avoid 

adverse eBccts to listed species. 
Uncertainties 

There remains a degree of uncertainty in assessing risks posed by fldenpyr ethyl 

degradates. The toxicity data on the degradates provided by the registrant suggest that S-1353- 

acid is more toxic to aquatic vascular plants than the parent compound (parent toxicity = 0.0 13 

mg/L; S-1353-acid toxicity = 0.0063 m). Although no terrestrial plant toxicity data were 

provided for the degadates, the aquatic toxicity data suggest the degradate could be more toxic 

to terrestrial plants than the pasent. Eurthrmoree, EED modeling shows the S-1353-acid 

degradate to be more mobile and persistent than parent flufenpyr-ethyl. Since the parent RQs 

border on the LOC for risk to non-target or endangered plants fkom combination of dritt and 

run06 C; asassumption fiom the aquatic toxicity data suggests possible risk &om runoff to 

terrestrial plants from the degadate. Because the degadate (5-1 353-acid) degrades slower than 

the parent compound in the environment, the herbicidal effects could be fiom the degradate, but 

this cahnot be verified without additional testing. 

Labeling Recommendations 

The following statements are to be included on the S-3153 WDG herbicide label: 

For Manukturing-Use Products: 

"Do not discharge effluent containing this active ingredient into lakes, streams, ponds, estuaries, 

oceans, or other public waters unless this product is specifically identified and addressed in an 

NPDES permit. Do not discharge effluent containing th product into sewer systems without 

previously not$& the swage treatment plant authority. For guidance, contact your State 

Water Board or Regional Office of EPA." 

For End-Use Products: 

"Do not apply directly to water or to areas where surface water or other sensitive areas may be 

exposed to spray drift, Do not contaminate water when disposing of equipment washwater or 

rinsate." 

"Do not apply this product through any type of irrigation system, Do not apply this product 

within one-half mile upstream of an active irrigation or potable water intake in flowing water (i.e., 

river, strq etc.) or within one-half* of an active irrigation or potable water intake in a 

standii body of water? such as a labe, pond, or reservoir. " 

Spray Drift Advisory 

The foIIowing label statements concerning aerial &@ reduction should appear on the label: 

Because of the high toxicity of fldenpyr-ethyl to plants, there-.is the potential for nontaget plants 
to be harmed by spray drift fkom treated areas. 

Potential label language to minimize spray driR could be: 

For aerial applications: 1) the distance of the outermost nozzles on the boom must not exceed 314 

the length of the wingspan or rotor; 2) applications should only occur in wind speeds between 3 

and 10 mph; 3) the nozzles must be directed toward the rear of the aimrail, at an angle between 0 

and. 15 degrees downward, 4) ASAl3 droplet size consistent with those presented should be stated 

(coarser sprays reduce expected risks), and 5) release height should be 10 feet or less above the 

surface or tops of vegetation. 
NEW CHEMICAL 

ENVIRONMENTAL FATE AND EFFECTS SCIENCE CHAPTER 

Environmental Fate and Ecological Risk Assessment 

For 

Flufenpyr Ethyl (PC Code No: 108853) 

and Two End-Use Products : 

S-3153 WDG Herbicide (57.6% a.i.) and S-3153fAtrazine WDG (1.9% a.i.) 

Environmental Fate and Effects Division Team Members 

Steve Carey, Biologist 

Thuy Nguyen, Chemist 

Secondary Reviewer 

William Erickson, Biologist 

Stephanie Syslo, RAPL 

Branch Chief 

Ben Smith 

Date of Approval 

9//+3 3 
Table of Contents 

Environmental Risk Assessment 

I . Environmental Risk Conclusions ....................................... 4 

I1 . Introduction ....................................................... 6 

A . Physical and Chemical Properties ..................................... 6 

B . ModeofAction ................................................... 7 

C . Use Characterization ............................................... 7 

D . Approach to Risk Assessment ........................................ 8 

I11 . Integrated Environmental Risk Characterization ....................... 10 

A . Terrestrial Ecological Risk .......................................... 10 

B . Aquatic Ecological Risk ............................................ 12 

IV . Environmental Fate Assessment ...................................... 12 

A . Integrated Assessment . Summary ................................... 12 

B . Environmental Persistence in Soil and Water ........................... 13 

C . Environmental Mobility and Exposure in Soil and Water .................. 14 

V . Water Resource Assessment .......................................... 15 

A . Models ......................................................... 15 

B . Drinking Water Assessment ......................................... 15 

1 . Surface Water ................................................. 15 

2 . Groundwater ................................................. 16 

C . Aquatic Exposure Assessment ....................................... 17 

VI . Aquatic Exposure and Risk Assessment ................................ 17 

Hazardsummary ................................................. 17 

ExposureSummary ............................................... 18 

Estimated of Risks to Aquatic Organisms and Plants ..................... 18 

Risk Assessment Summary ......................................... 19 

VII . Terrestrial Exposure and Risk Assessment ............................. 20 

Assessment of Risks to Terrestrial Animals ............................ 20 

Assessment of Risks to Insects ...................................... 21 

Assessment of Risks to Terrestrial Plants .............................. 22 

VIII . Risk to Endangered Species ....................................... 23 
APPENDICES 

I . Summary of Results Environmental Fate Studies ........................ 24 

I1 . Chemical Structures and Proposed Degradation Pathways ................. 34 

I11 . Water Resource Assessment ........................................ 43 

IV . Ecological Effects Toxicity Studies ................................... 58 

V . Ecological Risk Assessment ........................................ 66 

VI . Environmental Fate Data Requirements ............................... 76 

VII . Ecological Effects Data Requirements ................................ 77 

VIII . EllFate Output ................................................... 78 

IX . TerrPlant Output ................................................. 80 

X . SprayDrifl ...................................................... 82 
Environmental Risk Assessment 

I. Environmental Risk Conclusions 

A. Proposed Uses 

Flufenpyr ethyl is a new herbicide produced by Sumitomo Chemical Company Ltd. and under 

development in the United States by Valent U.S.A. Corporation. As a contact pyridazinone 

herbicide, flufenpyr ethyl could be used to control various broadleaf weed species through the 

disruption of the cell membrane and the inhibition of protoporphyringen oxidase in the chlorophyll 

biosynthetic pathway, which leads to a phytotoxic buildup of the intermediates. 

Valent USA Corporation is seeking registration of S-3153 WDG Herbicide (57.6% a.i) for 

use on soybean and sugarcane; and S-3153fAtrazine WDG (1.9 % a.i.) for use in sugarcane and 

field corn (except popcorn and sweet corn). Different application rates are proposed for each crop 

and each formulation. Sugarcane (S-3 153 WDG) has the highest combined maximum seasonal rate 

of 0.054 lb aiIA, Both aerial and ground application are allowed for S-3 153 WDG, however only 

ground application is permitted for S-3 153lAtrazine WDG. Although both labels are discussed in 

portions of this document, the risk assessment relates solely to the S-3153-WDG formulation as 

EFED does not have any toxicity data to appropriately assess the risks from the uses of S3 153lAtrazine formulation. 

B. Environmental Risks Summary 

EFED has considered all available information on the toxicity, the environmental fate 

properties, the potential use areas for sugarcane and soybean, and the application methods of 

flufenpyr ethyl in characterizing ecological risks related to the above mentioned uses. Based on the 

highest use rate, which is for S-3 153 WDG on sugarcane, the Level of Concern (LOC) of one is 

exceeded for non target endangered and non-endangered terrestrial plants growing near the treated 

sites that may be exposed to spray drift from ground or aerial application as shown in the following 

table. The endpoint exceeded is based on plant weight loss. These calculations are based on a 

presumption of five percent drift from aerial applications coupled with one percent runoff. Runoff 

scenarios, which are based on seedling emergence tests, did not result in any exceedance of an LOC. 

Endpoint 

Non-target plant, ground app. 

Non-target plant, aerial app. 

Endangered plant, ground app 

Endangered plant, aerial app 

Maximum RQ 

3 

15 

7 

3 4 
There is a degree of uncertainty for potential risk to terrestrial plants, if exposed to the 

degradates, since the terrestrial risk assessment is based on the parent flufenpyr-ethyl only. No 

toxicity data on the degradates were submitted by the registrant to determine if they have any 

potential to damage or kill terrestrial plants. While not necessarily comparable, tests of aquatic 

vascular plants suggest that the S-1353-acid is approximately twice as toxic as the parent. In 

addition, it is more persistent and mobile. 

As to terrestrial animals, aquatic organisms, and aquatic plants, the proposed uses should 

present minimal acute or chronic risks. However, it is important to note that these low risk estimates 

reflect the use at low proposed application rates. Toxicity testing actually indicates that flufenpyr 

ethyl is moderately toxic to freshwater fish and estuarine/marine invertebrates. There also was high 

dietary toxicity to mallard ducks as suggested by the avian reproductive studies. On the other hand, 

risks to honeybees from parent flufenpyr ethyl are not expected. 

The environmental fate data and the estimated concentrations from the EFED's water models 

indicate that flufenpyr ethyl metabolizes rapidly in soils and that under the most conservative 

scenarios, it will not reach surface and ground water resources at significant levels. As for its major 

degradates (S-3 153-acid, S-3 153-OH, S-3 153- 1 -OCH3), although more persistent and more prone 

to leaching than the parent, they are also not anticipated to present any major concern to drinking 

water resources, primarily due to the low use rates. 

C. Drinking Water Summary 

Flufenpyr ethyl is a new chemical, for which no monitoring data are available. Therefore, 

potential human exposure to flufenpyr ethyl and its major soil degradates (S-3 153-acid, S-3 153-1- 

OH, and S-3 153-1 -OCH,) fiom ingestion of drinking water was estimated using EFED's aquatic 

models. The drinking water estimated concentrations (DWEC) for surface and ground water are 

calculated using Tier 1 screening models FIRST (EQPA index _Reservoir Screening Tool) and SCIGROW (Screening Concentration in Groundwater), respectively. All three crops were modeled, 

however, for HED's human health risk assessment, EFED recommends the DWECs fi-om sugarcane 

scenario as it represents most conservative estimates. The DWECs from sugarcane use are listed 

below: 

DWECs for Human Health Assessment based on sugarcane use 

Surface Water: Peak (acute) 

Annual Average (chronic) 

Ground Water: Acute and Chronic 

Flufenpyr 

ethyl 

0.16 ppb 

0.004 ppb 

S-3153-1- 

OCH, 

1.5 ppb 

0.5 ppb 

S-3153-acid 

3.6 ppb 

1.5 ppb 

<0.O 1 ppb 

S-3153-OH 

0.35 ppb 

0.04 ppb 

<0.01 ppb 0.04 ppb <0.01 ppb 
D. Endangered Species 

The Agency's levels of concern for non-target and endangered terrestrial plants are exceeded 

for the proposed use of flufenpyr-ethyl on sugarcane and soybeans. This concern for terrestrial plants 

is based on spray drift to adjacent sites. As indicated in Appendix X, the Tier 1 Aerial Assessment 

Model predicts relatively high end (90th percentile) drift deposition values. Nevertheless, because 

there is a relatively flat slope for the toxicity endpoints, a large no spray zone would be required for 

plants with responses analogous to the three most sensitive dicots. Numbers would be reduced if 

extremely coarse spray was used. 

Nevertheless, at it currently stands, the applicant must provide information on the proximity 

of Federally listed endangered and threatened terrestrial plants to the proposed use sites. This 

requirement may be satisfied in one of three ways: 1) having membership in the FIFRA Endangered 

Species Task Force (Pesticide Registration [PR] Notice 2000-2); 2) citing FIFRA Endangered 

Species Task Force data; or 3) independently producing these data, provided the information is of 

sufficient quality to meet FIFRA requirements. The information will be used by the OPP 

Endangered Species Protection Program to develop recommendations to avoid adverse effects to 

listed species. 

11. Introduction 

A Physical / Chemical Properties 

Common name: Flufenpyr ethyl (IS0 pending) 

Synonyms: S-3 153, V-3 153 

Chemical Name: Acetic acid, 12-chloro-4-fluoro-5- (5-methyl-6-oxo-4- 

(trifluoromethy1)- 1 (6H)-pyridazinyl) phenoxyl-,ethyl ester 

CAS Registry No. 188489-07-8 

Molecular formula: C,,H,,N,O,F,Cl 

Molecular weight: 408.7 

Physical state: Odorless, Off-white powder 

Vapor pressure: 3.8 x Pa at 20 "C 

Solubility (@ 20 "C): 4.1 mg/L in water 

B. Mode of Action 

Flufenpyr ethyl is a new herbicide produced by Sumitomo Chemical Company Ltd. and under 

development in the United States by Valent U.S.A. Corporation. As a contact herbicide, flufenpyr 

ethyl is proposed for use to control post emergence broadleaf weed species through disruption of the 

cell membrane. It also induces the inhibition of protoporphyringen oxidase in the chlorophyll 

biosynthetic pathway that leads to a phytotoxic buildup of intermediates. The later process requires 

the presence of both light and oxygen. 
C. Use Characterization 

Flufenpyr ethyl technical will be formulated as a water dispersable granule, S-3 153 WDG 

herbicide, containing 57.6% flufenpyr ethyl as the active ingredient. Additionally, a water 

dispersable granule premix formulation, S-3 153lAtrazine WDG, containing flufenpyr ethyl (1.9%) 

and atrazine (75%) as active ingredients will also be manufactured. This is the first application for 

a United States registration of products containing flufenpyr ethyl. Table 1 summarizes the 

proposed uses for flufenpyr ethyl. Note that although both labels are presented here, this document 

will be solely based on the S-3 153-WDG formulation, since no toxicity data were submitted on the 

formulation with Atrazine. 

The label for S-3 153 WDG recommends broadcast application for soybean and ground drop 

nozzle application for sugarcane. However, it does not specifically prohibit the use of aerial or band 

application. Each crop could be treated up to two applications per a season, 10 to 14 days apart, and 

at a maximum rate of 0.027 lb ai1A per application. 

Table 1. 

Uses 

Field Corn 

Sugarcane 

Soybeans 

The label for S-3 153 WDGIAtrazine only allows ground drop nozzle application for field corn 

and sugarcane. Aerial application and application through any type of irrigation system are 

prohibited by this label. Also, although that the label allows a maximum single application rate of 

0.019 lb ai/A for field corn, twice a season, it limits the maximum seasonal application to 0.0323 

lb ai1A. Similarly, for sugarcane, 0.0355 lb ailA is permitted per application, but only up to 0.0532 

1b ailacre is allowed per season. 

Based only on USDA information (htt~://www.usda.gov) on states in which the these crops 

are commonly grown, flufenpyr ethyl will be used on approximately 74 million acres of soybeans 

predominantly in Iowa, Illinois, Minnesota, Indiana, and Nebraska (Figure 1); and 1 million acres 

of sugarcane predominantly in Florida, Louisiana, Hawaii, and Texas (Figure 2). 

Pro3osed Use Information for Flufenqyr 

Product/ 

Formulation 

S-3 153 / 

Atrazine WDG 

S-3 153 WDG 

S-3 1 53 / 

Atrazine WDG 

S-3 153 WDG 

Ethyl 

Max Application 

Rate 

(lb ai/acre) 

0.019 

0.027 

0.0355 

0.027 

No. 

AppVyea 

r 

2 

2 

2 

2 

Max Appl Rate 

per year 

( lb ai/acre) 

0.0323 

0.054 

0.0532 

0.054 

Application 

Interval 

(days) 

10 

10 -14 

10 

10 - 14 

PHI 

(days) 

not 

specified 

90 

90 

45 
Figure 1 - Soybeans Acreage in the U.S.A. 

100,000 to 149,999 CitattdBy: 

USDA National A-hural 15!3,000+ Statistics Sake 

Figure 2 - Sugarcane Acreage in the U.S.A., except Hawaii 

ested Acres by County 

Not Estimatzd 

<5,000 

5,000 to 9,999 

10,000 to 24,999 

25,000 to 49,999 

C] 50,000to 99,999 Crcaabd By: 

100,OOO + USDA National Agdcuhural 

Statistics Scsvicx 
D. Approach to Risk Assessment 

EFED's approach to this risk assessment is based on exposure (chemistry, use, fate, etc.) and 

effects data (acute and chronic toxicity studies for terrestrial animals and aquatic organisms and 

plants). The initial evaluation is focused on the development of a deterministic point estimate 

approach, which is the ratio of model derived estimated environmental concentration (based on the 

maximum application rate) of a compound to a protective toxicity effects value (acute [e.g., LC,,, 

LD,,, or EC,,] and chronic [NOAEC]). The resulting Risk Quotients (RQ = exposure estimate 

[EECIltoxicity) are then compared to the Agency's Levels of Concern (LOC), which address the 

following risk presumption categories: 

Risk Presumption Categories 

I I 1 I Risk Presum~tion for Terrestrial Animals I LOc I 

Acute Endangered Species: endangered species may be adversely affected by use j 0.1 

Acute: Potential for acute risk for all non-target organisms 

Acute Restricted Use: Potential for acute risk for all non-target organisms, but may be 

mitigated through restricted use classification 

Chronic Risk: potential for chronic risk may warrant regulatory action 1 I 

0.5 

0.2 

Risk Presumption for Aquatic Organisms 

I Acute Restricted Use: Potential for acute risk for all non-target organisms, but may be 

mitigated through restricted use classification I 

LOC 

Acute: Potential for acute risk for all non-target organisms 

I 

0.5 

I 

Acute Endangered Species: endangered species may be adversely affected by use 0.05 

Chronic Risk: potential for chronic risk may warrant regulatory action 

Given the minor risk concerns to terrestrial animals and aquatic organisms from flufenpyr ethyl 

based on a screening evaluation, this risk assessment focuses on non target terrestrial plants that 

grow adjacent to the treated areas. 

I 

1 

Risk Presumption for Terrestrial and Aquatic Plants 

Although flufenpyr ethyl metabolizes rapidly in soils and forms a series of more persistent and 

more mobile degradates, the terrestrial risk assessment can only be based on the parent, since no 

toxicity data were submitted for the degradates for terrestrial plants and animals. The aquatic risk 

assessment is based on parent flufenpyr-ethyl for aquatic organisms and plants, and on parent and 

its degradates for aquatic vascular plants. 

I 

LOC = 1 

For terrestrial animals, EFED used the ELLFATE model to calculate the EECs on potential 

bird and mammal food items (grasses, other green vegetation, seeds, insects). EECs are based on 

two direct applications of flufenpyr-ethyl at the maximum allowed single rate of 0.027 lb aiIA. Since 

no foliar dissipation half life was available for flufenpyr-ethyl, EFED also assumed a default half-life 

value of 35 days. This default half-life of 35 days is based on foliar dissipation data for pesticides 

for which such data are available, and is designed to be conservative (Willis and McDowell, 1987). 
For terrestrial plants inhabiting dry (i.e., adjacent to treatment site) and semi-aquatic (i.e, areas 

receiving channelized runoff) areas, RQs are estimated based on the amount of pesticides present 

on the soil surface due to runoff or spray drift. EFED's scenario for runoff from one treated acre to 

an adjacent area (sheet runoff) and 10 treated acres to a distant low-lying area (channelized runoff) 

is based on: 1) solubility and the amount of pesticide present on the soil surface and its top one inch 

and 2) the percent of runoff values of 0.01,0.02, and 0.05 for water solubility of 40 ppm, 10-100 

ppm, and >lo0 ppm, respectively. Spray drift exposure from ground application is assumed to be 

1 % of the application rate. Spray drift fiom aerial, airblast, forced-air, and chemigation applications 

is assumed to be 5% of the application rate. EECs are calculated for the following application 

methods: (1) unincorporated ground applications and (2) aerial, airblast, forced-air, and chemigation 

applications. For detailed information regarding the estimation of spray drift, refer to Appendix X. 

For acute exposure to aquatic organisms and aquatic plants, EFED relied on the maximum 

Estimated Environmental Concentration (EEC) values generated through GENEEC2. For chronic 

exposure to fish and invertebrates, the 60-day and 21-day GENEEC2 averages were used, 

respectively. Exposure is based on the highest allowable seasonal rate of 0.054 lb ai/A, equally 

divided among two aerial applications at 10 days apart. 

111. Integrated Environmental Risk Characterization 

A. Terrestrial Ecological risk 

Plants: The results of this risk assessment indicate that terrestrial vascular plants may 

potentially be at risk if exposed to the proposed uses of parent flufenpyr-ethyl on sugarcane and 

soybeans. Based on the most sensitive species selected from the seedling emergence (lettuce) and 

vegetative vigor (tomato) toxicity tests, flufenpyr ethyl poses significantly greater threat to postemergence plants (RQs of 0.05 - 0.3 1 for pre-emergence plants vs. 3 - 34 for post-emergence plants). 

The RQYs for flufenpyr ethyl as shown in Appendix IX, paragraphs 1 and 2, exceed the LOC for 

potential risk to non-endangered and endangered plant fiom spray drift alone for both methods of 

application (ground or aerial). With a tomato EC2, of 0.00009 lb ai/A for non-endangered plants and 

a NOAEC of 0.00004 lb ai/A for endangered plants, the drift LOCs are exceeded with a RO range 

of 3 (non-endan~ered species) to 7 (endangered species) for ground applications and a RO range of 

15 (non-endangered species) to 34 (endangered species) for aerial applications when terrestrial plants 

in areas adjacent to the treated sites are exposed to parent flufenpyr-ethyl. However, based on 

seedling emergence toxicity values, the same use pattern results in no LOC exceedance (RQ 4) for 

terrestrial plants fiom runoff alone. 

Although the above assessment reflects risk to terrestrial plants fiom the most sensitive species 

tested in the vegetative vigor study (tomato), there is considerable variability in sensitivity to 

flufenpyr-ethyl. For vegetative vigor testing, flufenpyr-ethyl was sprayed onto ten species (corn, oat, 

onion, ryegrass, soybean, lettuce, radish, cucumber, cabbage, and tomato) at levels up to 0.029 lb 

ai/A. Because the risk quotient is a linear function of threshold, one can project which species would 

have LOC exceedances by simple proportional analysis. In the case on non-target plants (tomato 

based RQ of 7 corresponding to 0.00009 lb ai/A), one post-emergence application at 0.027 lb ailA 

would trigger LOC exceedances for non-target plants for only lettuce, tomato, and cucumbers due 
to spray drift from treated sites (i.e. less than 0.00063 lb ai/A). For endangered plants, a toxicity 

value calculated at 0.00136 lb ai/A results in a risk quotient of 1 and toxicity values (NOAEC for 

endangered plants) of 0.001 l,0.0011, 0.00012, and 0.00004 lb ai/A for radish, cabbage, cucumber, 

and lettuce, respectively, are below the calculated value resulting in higher risk quotients. 

The seedling emergence and vegetative vigor studies suggest this chemical exhibits 

considerable toxic selectivity. It can be assumed that there may also be similar variation in the 

general non-target plant population. However, there are uncertainties in having ten tested species 

represent the universe of non-target plant species. In addition, measurable endpoints were based on 

growth effects (shoot weight, shoot height) and observed physical injury. Currently, EPA does not 

measure reproduction effects in plants and therefore is not able to adeptly characterize herbicidal 

effects. 

Additional uncertainty is introduced because environmental fate data suggest that flufenpyr 

ethyl will degrade rapidly in soils to form a series of more persistent metabolites. The toxicity data 

on the degradates provided by the registrant suggest that S-1353-acid is more toxic to aquatic 

vascular plants than the parent compound (parent toxicity = 0.013 mg/L; S-1353-acid toxicity = 

0.0063 mg/L). Although no terrestrial plant toxicity data were provided for the degradates, based 

on the aquatic toxicity data, this degradate could also be more toxic to terrestrial plants than the 

parent. The environmental fate data also show S-1353-acid to be more persistent and likely to 

accumulate at higher concentrations in ground and surface waters than parent flufenpyr-ethyl. Since 

the parent RQs border on the LOC for risk to non-target or endangered plants from combination of 

drift and runoff, the assumption from the aquatic toxicity data suggests possible risk from runoff to 

terrestrial plants from the degradate. Furthermore, with the degradate (S-1353-acid) degrading 

slower in the environment than the parent, the herbicidal effects could be greater from the degradate 

than from the parent. 

Because the degradates are mobile and persistent, yet another pathway of potential concern 

exists with respect to flufenpyr-ethyl. Literature and past incidents with other herbicides suggest the 

potential for possible damage to terrestrial plants from surface or ground waters contaminated with 

phytotoxic compounds. The inadvertent use of waters contaminated with flufenpyr-ethyl degradates 

in irrigation systems could pose a potential risk to the irrigated crops through this pathway. This 

concern is multiplied by the fact that flufenpyr-ethyl exhibits more toxicity from foliar uptake than 

stem or root uptake. 

Based on the above reasons and uncertainties, EFED recommends Tier I1 terrestrial plant 

toxicity tests (Seedling Emergence and Vegetative Vigor) with the S-1353-acid degradate in order 

to determine the degradate's toxicity to terrestrial plants, to better characterize runoff and spray drift 

to non-target plants, and to determine risks to irrigated crops from contaminated surface waters. 

Animals: The proposed use sites of flufenpyr-ethyl are not likely to pose any potential acute 

or chronic risk to birds or mammals since toxicity tests indicate that they are not sensitive to 

exposure to the active ingredient. In the toxicity tests, no acute effects are observed after exposure 

to the highest concentration tested according to testing guidelines. While there were chronic avian 

effects at the 164 ppm level, this is considerably higher than the peak modeled concentration of 

flufenpyr-ethyl on short grass of 12 ppm. 
Honey bees: Toxicity results for the honeybee test indicated that flufenpyr-ethyl is practically 

non-toxic to honeybees (LD,, >25 ug/bee) on an acute contact basis. It is therefore expected that 

potential risks to honeybees are minimal. 

B. Aquatic Ecological Risk 

The proposed uses of flufenpyr-ethyl are likely to pose minimal potential acute or chronic risk 

to fish or invertebrates (freshwater or estuarinelmarine), primarily because of the low application 

rates. For freshwater fish, effects were observed in the ppm range with an acute LC,, of 3 ppm for 

bluegill and a chronic NOAEC of 0.4 ppm for trout. Interestingly, Daphnia did not have an LC,, at 

the highest level tested, but an analogous chronic value to the trout, while Mysid Shrimp had a 

similar acute value to bluegill. Mysid were not tested for chronic effects. Regardless, the estimated 

Tier I surface water screening model (GENEEC2) peak, 21-day, and 60-day concentrations of 

flufenpyr-ethyl of 0.3,0.2, and 0.1 ppb, respectively, will not result in any LOC exceedance for acute 

or chronic risks of aquatic organisms. 

Results from this risk assessment indicate that aquatic plants (vascular and non-vascular) are 

not likely to be exposed to flufenpyr-ethyl or its degradates at levels of concern. No LOCs were 

exceeded for aquatic plants and potential risk is expected to be minimal. 

IV. Environmental Fate Assessment 

A. Integrated Assessment - Summary 

Flufenpyr ethyl is an odorless off-white powder. Based on a solubility in water of 4.1 mg/L 

at 20 "C, a vapor pressure of 3.8 x Pa at 20 OC, and a melting point of 100 - 101 OC, EFED 

predicts that volatilization may not be a significant dissipative pathway for flufenpyr ethyl. A Log 

Po, of 2.99 % 0.05 also indicates the bioaccumulation potential of this chemical in fish could be 

negligible. 

Flufenfyr ethyl is not expected to persist in the environment, nor in soil or water. In water, it 

degrades quickly via direct sunlight. Hydrolysis in neutral and alkaline water is also fast. On soils, 

flufenpyr ethyl biodegrades within hours under aerobic soil and anaerobic aquatic conditions, but 

remains stable to photolysis. 

Flufenpyr ethyl and its degradates are potentially mobile in soil, according to laboratory 

adsorption data. However, field dissipation studies shows that leaching for parent and degradates 

does not occur below the 3" soil depth. Table 2 summarizes the degradateslmetabolites reported in 

the environmental fate studies. 
Table 2 Routes of degradation for degradateslmetabolites of Flufenpyr ethyl 1 I I I 

Degradates Hydrolysis Photolysis 

(water, pH 5) 

rnax 8.7% at 

day 30 (pH 5) 

max 92% at 

day 30 (pH 7) 

max 99% at 

Photolysis 

(soil) 

Aerobic 

Soil 

rnax 84% at 

day 1 

day 30 (pH 7) 

max51%at 

rnax 41% at day 15 

S-3 153-DHPY 

S-3 153-acid-2,4-(OH)2 

TFPYR 

max 23% at day 7 

max 13% at day 32 

max 11% at day 20 

S-3153-1-OCH3 * 

S-3153-1-OH 

max 53% at 

day 177 

max 14% at 

day 91 

S-3 153-1-OCH3-5'- 

CH20H 

S-3 153-f formate 

Anaerobi 

c Aquatic 

rnax 82% at 

day 1 

max 19% at 

day 365 

Unknown 1 

max 84% at 

day 185 

max 14% at 

day 365 

Terrestrial 

Field 

' Included in DWEC calculations, based on MARC decision 

max 33% at 7 

hour 

rnax 8% at day 2 

rnax 15% at day 1 

rnax 18% at day 

13 

max7%at day 2 

rnax 1% at day 

300 

rnax 11%atday2 

The suggested degradation pathways and the chemical names and structures of the degradates 

are listed in Appendix 11. 

Based on EFED's laboratory and field data and the decision of the HED's Metabolism 

Assessment Review Committee (MARC), EFED determines that the degradates of importance to 

drinking water resources are S-3 153-acid, S-3 153-1-OH, and S-3 153-1-OCH3. Only these 

degradates will be evaluated in this report. 

B. Environmental Persistence in Soil and Water 

Based on a solubility in water of 4.1 mg/L at 20 OC, a vapor pressure of 3.8 x 10-7 Pa at 20 OC, 

and a melting point of 100 - 101 OC, EFED predicts that volatilization may not be a significant 

dissipative pathway for flufenpyr ethyl. A Log Po, of 2.99 * 0.05 also indicates the bioaccumulation 

potential of this chemical in fish could be negligible. 

In the laboratory studies, flufenpyr ethyl does not persist in water nor in soil systems. In water, 

photolysis in acidic environment is fairly rapid (t ?4 < 5 days), while the rate of hydrolysis is 

dependent on the pH of the water. Flufenpyr ethyl remains quite stable in acidic water (t ?4 =: 300 

days), but degrades within weeks in neutral water (t !4 = 8 days) and within hours in alkaline water 
(t ?4 = 3 hours), forming mostly S-3 153-acid. Due to brief duration of the studies, no obvious 

formation and decline pattern of this degradate was observed . On soils, flufenpyr ethyl metabolizes 

quickly (t ?4 < 2 hours) to S-3 153-acid. Three other major metabolites are also subsequently formed, 

S-3 153-1-OH, S-3 153-1 -OCH, and S-3 1 53-1-OCH,-5'-CH,OH, along with some minor amounts 

of CO,, S-3 153-1-OCH,-5'-COH and bound residues. The calculated half lives are 38 days for S3 153-acid, 7 days for S-3 153- 1 OH, and 47 days for S-3 153-1 OCH,. In a sediment-water system, 

rapid degradation of flufenpyr ethyl (t ?4 < 2 hours) to S-3 153-acid is also noted. S-3 153-acid in turn 

degrades (t % - 3 days) to S-3153-1-OH, which seems to be more persistent under anaerobic 

conditions (t ?4 = 866 days) than under aerobic conditions (t ?4 = 108 days). Both S-3 153-acid and 

S-3 153- 1 -OH are major metabolites in the sediment-water system. 

In field studies, flufenpyr-ethyl degrades within hours to S-3 153-acid. S-3 153-acid degrades 

with an estimated half life of approximately four days to two weeks to form S-3 153-1-OH and S3 153-1-OCH,. The later two metabolites seem to be more persistent than the parent as they were 

still detected one year after treatment, albeit at low levels (<lo% of parent). 

C. Environmental Mobility and Exposure in Soil and Water 

The estimated KO, value fi-om the Leaching and AdsorptiodDesorption studies indicates that 

flufenpyr ethyl has some leaching potential. However, since other dissipation routes such as 

degradation and mineralization are more important and much more rapid, the likelihood of flufenpyr 

ethyl leaching into ground water is greatly reduced. In contrast, two of its major metabolites, S3 153-acid and S-3 153- 1 -OH, seem to be more mobile and could have more ability to reach ground 

water than the parent. SCI-GROW model results show that S-3 153-acid could reach ground water 

at a higher level than the parent. However, in the field studies, neither flufenpyr ethyl nor the 

degradates were detected below the 6" soil depth. 

The environmental fate data, physical-chemical properties, and surface water modeling results 

suggest that drift immediately after application, if any, may be the most important route for transport 

of flufenpyr to surface water. However, once in water, flufenpyr ethyl is prone to hydrolysis, except 

in acidic aquatic environment, and should not present a major concern to surface water resources. 

As for the degradates, results fi-om the EFED water models predict higher surface water 

concentrations than for the parent. It should be noted that there are several levels of uncertainty 

when modeling the degradates which could lead to a high bias in results. Because there was an 

incomplete database, several default assumptions were made, including stability of degradates to 

hydrolysis and photolysis. These assumptions may be erroneous since their molecular formulae, 

especially for S-3 153-acid, suggest higher solubility in water and higher susceptibility to hydrolysis. 

A detailed assessment and characterization of Drinking Water Estimated Concentrations can be 

found in Appendix 111. 

Appendix I summarizes the findings from all of the environmental fate studies, the MRID 

number associated with each study, and the status of the studies. 
V. Water Resources Assessment 

A. Models 

Flufenpyr ethyl is a new chemical, for which no monitoring data are available. Exposure 

concentrations for drinking water and aquatic ecosystems assessments were estimated based on 

EFED's aquatic models listed below. Detailed description and documentation for these models can 

be found at: htt~://www.e~a. ~zovlo~pefed 1 /models/water/index.htm. A detailed Tier 1 Screening 

Level aquatic exposure assessment for human health and ecological risk assessment is attached in 

Appendix 111. 

Table 3 Models Used to Estimate Exposure Concentrations for Drinking Water and Aquatic and 

Ecosystem Assessments 

I Exposure Estimates 1 Models I I 

Drinking water, I FIRST @QPA Index geservoir Screening Tool) (version 1 .O, 

I Surface water l~u~ust 1,2001) I 

Drinking water 

Ground water 

SCIGROW (Screening Concentration In Ground 

- Water).(version 2.1; November 1, 2001)* 

(Tier 1) 

Aquatic ecosystems 

Surface water 

*While use of this version is provisional, it is expected to produce more accurate estimated values for compounds with 

- 

GENEEC2 (GENeric Estimated Environmental Concentration) 

(version 1 .O, August 1, 2001) 

(Tier 1) 

Terrestrial ecosvstems 

Groundwater as a source of irrigation 

(Tier 11 

longer half-lives. In most cases, a majority ofthe use area will have groundwater that is less vulnerable to contamination 

than the areas used to drive the SCIGROW estimates. 

SCIGROW (Screening Concentration In Ground 

mter).(version 2.1; November 1,2001)* 

The input parameters used in this assessment were selected from the environmental fate data 

submitted by the registrant and in accordance with US EPA-OPP EFED water model parameter 

selection guidelines, Guidance for Selecting Input Parameters in Modeling the Environmental Fate 

and Transport of Pesticides, Version 11, February 28,2002 The general input values used in the 

model runs are presented in Table 111-6 of Appendix 111. 

B. Drinking Water Assessment 

The HED Metabolism Assessment Review Committee (MARC) recommend the inclusion of 

four major degradates of flufenpyr ethyl (S-3 153-acid, S-3 153-1-OH, S-3 153-1-OCH,, and S-3 153- 

1 -OCH,-5'-CH,OH ) into the drinking water assessment of parent flufenpyr ethyl . However, at this 

time, the drinking water concentration estimation for S-3 153-1 -OCH,-5'-CH,OH is not possible due 

to insufficient fate data for this degradate. 

Surface Water 

The Drinking Water Estimated Concentrations (DWEC) for surface water used in human health 

assessment were determined using the Tier 1 model FIRST, version 1, August 1,200 1. 

FIRST is a screening model designed by EPA-OPPIEFED to estimate the concentrations found 
in vulnerable drinking water sources (a reservoir adjacent to fields treated with the pesticide in 

question. 

FIRST accounts for Percent Cropped Area (PCA). The PCA factor is 41% for soybean. No 

PCA was developed for sugarcane and a default value of 87% was used for this crop. The PCA is 

a generic adjustment which represents the maximum percent of any watershed that is planted to the 

crop being modeled and, thus, may potentially be treated with the pesticide in question. PCA factors 

are generated from Geographic Information System (GIs) overlays of cropping area and watershed 

delineations. EFED believes that the default value of 87% is probably high for sugarcane and the 

results reported for that crop could be overestimated. The DWECs, reported in Table 4 for 

flufenpyr ethyl and in Table 5 for the degradates, were based on the input parameters listed in 

Appendix 111. All three crops were modeled for the parent and as expected, the results for sugarcane 

are the highest due to the high PCA value (87%). Only the most conservative estimates, which are 

for sugarcane, were reported for the degradates. 

Table 4- Flufenpyr ethyl DWECs 

Sugarcane 

0.027 lb ai/A, 2 appl at 

1 0-day interval 

Aerial application 

' PCA = 0.87 

Ground Water: Acute and Chronic I <0.01 ppb I <0.01 ppb I ' PCA = Percent Cropped Area. See "Description of Model Inputs and Results" section for more information 

Soybean 

0.027 lb ai/A, 2 appl at 

1 0-day interval 

Aerial application 

'PCA = 0.41 

Surface Water: Peak (acute) 

Annual Average (chronic) 

Ground Water 

SCI-GROW model was used to estimate the level of flufenpyr ethyl residues in ground water. 

Based on the highest application rate and the most conservative selection of environmental fate 

parameters (see Appendix 111), ground water contamination, as a result of flufenpyr ethyl use on the 

proposed crops, was estimated to be below 0.01 ppb. This is in agreement with the terrestrial field 

0.161 ppb 

0.004 ppb 

Table 5 - Flufenpyr ethyl degradates DWECs- based on Sugarcane crop (PCA ' = 87%) 

0.076 ppb 

0.002 ppb 

Surface Water: Peak (acute) 

Annual Average 

(chronic) 

Ground Water: Acute and Chronic 

' PCA = Percent Cropped Area. See "Description of Model Inputs and Results" section for more information 

The single application rate of each degradate was adjusted from the proposed rate of sugarcane proportionally to the degradate's 

maximum detected concentration, relative to the total amount applied and to their molecular weight. 

S-3153-acid 

0.021 lb ai/A, 

2 appl at 1 0-day 

interval 

3.6 ppb 

1.5 ppb 

0.04 ppb 

S-3153-1-OH 

0.003 lb ai/A, 

2 appl at 10-day 

interval 

0.3 ppb 

0.04 ppb 

<0.01 ppb 

S-3153-1-OCH, 

0.012 lb ai/A, 

2 appl at 10-day 

interval 

1.5 ppb 

0.5 ppb 

<0.01 ppb 
dissipation study results where no flufenpyr ethyl was detected in the deep soil layers at above the 

study detection limit (2 ppb). 

C. Aquatic Exposure Assessment 

For surface water contamination, the estimated environmental concentrations (EEC) were 

calculated using GENEEC2 (meric Estimated Environmental Concentration). Results for use of 

flufenpyr ethyl on sugarcane are reported in Table 6, since it has the highest application rate among 

the proposed crops (2 applications per year at 0.027 lb ai/A each, with a 10-day interval between 

application). Aerial application was also assumed, since it gives the highest level of surface water 

contamination. The single application rate of each degradate was adjusted from the proposed rate 

of sugarcane proportionally to the maximum detected concentration of each degradate relative to the 

total amount applied and to their molecular weight. No drift was assumed for the degradates as they 

were formed after the parent reached the soils and no PCA adjustment was required for these surface 

water EECs. 

Table 6 - Surface Watel 

I Flufenpyr Ethyl 

0.027 lb ai/A, 2 appl at 

1 0-day interval 

S-3153-acid 

0.02 1 lb ai/A, 2 appl at 

1 0-day interval 

S-3153-1-OH 

0.003 lb aUA, 2 appl at 

1 0-day interval 

2.19 ppb 1 2.19 ppb 1 2.15 ppb 1 2.08 ppb 1 2.03 ppb 

ZECs for Ecological Risk Assessment 

Peak 

0.279 ppb 

For ground water contamination, as reported above in the Drinking Water Assessment 

section V. B, SCI-GROW estimated that flufenpyr ethyl residue concentration will be less than 0.01 

PP~. 

0.215 ppb 

VI. Aquatic Exposure and Risk Assessment 

Average 

4-day 

0.270 ppb 

Hazard Summary: 

0.212 ppb 

Flufenpyr-ethyl was shown to be moderately toxic to freshwater fish (LC,, = 2.5 - 3.75 ppm) 

and estuarinelmarine invertebrates (EC,, = 2.08 ppm) on an acute basis. However, the toxicity of 

flufenpyr-ethyl to freshwater invertebrates and estuarinelmarine fish was not seen at the solubility 

limit in aquatic environments (4.1 pprn in water). Based on the Tier I1 duckweed toxicity testing, 

the EC,,values of the parent flufenpyr-ethyl and its degradates S-3 153 acid and S-3 153-4-OH were 

0.013,0.006, and >0.03 ppm, respectively. The Tier I1 non-vascular aquatic plants toxicity testing 

with the parent compound shows freshwater green alga (Selenastrum capricornutum) as the most 

sensitive non-vascular plant, with an EC,, of 0.009 ppm. Although chronic values were not 

Average 

21-day 

0.191 ppb 

0.196 ppb 

Average 

60-day 

0.101 ppb 

Average 

90-day 

0.070 ppb 

0.165 ppb 0.145 ppb 
determined for estuarinelmarine fish; freshwater early life stage and invertebrate life cycle values 

(NOAECILOAEC) were shown to be 0.4410.92 ppm and 0.4611.2 ppm, respectively, with significant 

reductions occurring in fish growth and invertebrate reproduction. In addition, the toxicity tests with 

aquatic organisms and plants, the solvent was used to maximize the chemical dissolution, exceeding 

EFED's guideline recommended range by 1 -fold. None of the aquatic organisms and plants were 

adversely affected by the solvent in these tests. 

Surface water modeling results for the crops considered in this assessment were based on the 

Tier 1 modeling using GENEEC2. The surface water concentrations used to estimate acute risks 

from exposures of aquatic fish and invertebrates to flufenpyr-ethyl are based on estimated peak 

values. Surface water concentrations used to estimate chronic risks to aquatic invertebrates are based 

on estimated 21 -day average values. Concentrations in surface water used to estimate chronic risks 

to aquatic fish are based on estimated 60-day average values. Sugarcane was modeled as the most 

conservative case scenario for aquatic exposure. Tier 1 screening level exposure estimates with 

GENEEC2 are tabulated in Table 7 and detailed in Appendix 111: 

Estimates of Risks to Aauatic Organisms and Plants 

Table 7. EECs (ppb) of Flufenpyr-ethyl and its Degradates Residues in Surface Water Using GENEEC2 model 

A means of integrating the results of exposure (EEC) and toxicity data is called the quotient 

method. For this method, risk quotients (RQs) are calculated by dividing exposure estimates by 

toxicity values, both acute and chronic. 

RQ = EXPOSUREITOXICITY 

60-day 

0.101 

2.08 

0.164 

The toxicity test values (i.e., measurement endpoints) used in the acute and chronic risk 

quotients are derived from the results of required studies. The EEC, toxicity, and risk quotient values 

are provided below in Table 8. 

21-day 

0.191 

2.15 

0.196 

4-day 

0.270 

2.19 

0.212 

Compound 

Parent Flufenpyr-ethyl 

S- 13 53-acid degradate 

S- 1353-4-OH degradate 

Peak 

0.279 

2.19 

0.215 
Table 8 - Toxicity, Exposure, and Risk Quotient Values of Flufenpyr-ethyl (based on two aerial application of 0.027 

lb ai/A, 10 days interval) 

Risk Assessment Summary: 

Species 

Rainbow trout-Acute 

Daphnia magna-Acute 

Daphnia magna-Chronic 

Rainbow trout--Early Life Stage 

Estuarineimarine fish- Acute 

Shrimp -Acute 

Eastern Oyster--Shell deposition 

Aquatic Plants-Duckweed (parent) 

Aquatic Plants-Duckweed (S 13 53 acid) 

Aquatic Plants-Duckweed (S 135340H) 

Aquatic Plants- Selenastrum capricornutum 

Aquatic Plants- Naviculapelliculosa 

Aquatic Plants- Skeletonema costatum 

Aquatic Plants- Anabaenaflos-aquae 

' surface water concentrations (EECs) are shown 

As shown in table 8, no LOCs were exceeded for aquatic organisms exposed to parent 

flufenpyr-ethyl and for aquatic plants exposed to parent flufenpyr-ethyl and its degradates. 

Therefore, risks to fish, invertebrates, and aquatic plants are believed to be negligible. Also, since 

flufenpyr-ethyl is not persistent (half life - 7 days) in aquatic environments, exposure fiom this 

scenario based on GENEEC2 modeling with peak (acute) values of 0.3,2.2,0.2 ppb for parent, S3 153-acid, and S-3 153-1 -OH, respectively, should not present a concern for any aquatic organisms 

or plants from the proposed use sites of sugarcane and soybean since the toxicity values are at or 

greater than 440 ppb. 

At the chronic level, reproductive effects and growth effects were identified in fieshwater 

invertebrates and fish respectively. However, since the flow-through test maintains a constant 

concentration, it is not an accurate representation of what is expected to occur in the environment. 

The simulated aquatic exposure profile for each proposed use of flufenpyr-ethyl differs from the 

constant exposure in the flow-through test because of rapid degradation of parent flufenpyr-ethyl. 

The significance of the unrealistic constant concentration in the flow-through test is not completely 

clear. Since chronic effects to invertebrates and fish are not studied throughout the flow-through 

test, one cannot determine whether 21 or 60 days of exposure at the EC,,/LC,, concentration were 

necessary to cause the effects, or if a shorter exposure at that parent concentration would suffice. 

Regardless, risk quotients did not exceed levels of concern. 

Toxicity 

(ppm) 

2.5 

>3 

1.2 

0.92 

>2.7 

2.08 

>2 

0.013 

0.006 

>0.03 

0.009 

0.16 

0.012 

B0.05 

in ppm. 

Exposure1 

(ppm) 

0.00028 

0.00028 

0.00019 

0.0001 

0.00028 

0.00028 

0.00028 

0.00028 

0.0022 

0.0002 

0.00028 

0.00028 

0.00028 

0.00028 

Risk Quotient 

(RQ) 

<O.O 1 

<0.01 

<0.01 

<0.01 

<0.01 

<0.01 

<0.01 

0.02 

0.36 

<0.01 

0.03 

<0.01 

0.02 

<0.01 
VII. Terrestrial Exposure and Risk Assessment Summary 

Assessment of Risks to Terrestrial Animals 

Toxicity to Terrestrial Animals: 

Data submitted to and reviewed by the Agency (D268736) show that flufenpyr-ethyl is 

practically non toxic to non-target terrestrial animals. 

Flufenpyr-ethyl is nontoxic to birds on both an acute (LD,, >2250 mgkg) and subacute dietary 

basis (LC,, >5620 mg/kg of diet). However, significant adverse reproductive effects (reduction in 

14-day-old survivor/normal hatchlings and final weight of female mallard ducks) were reported at 

a concentration of 164 ppm flufenpyr-ethyl in the diet. 

Flufenpyr-ethyl is practically nontoxic to mammals on an acute exposure basis (LD,, >5000 

mgkg) and on a chronic exposure basis (NOAEC = 1463 ppm). Flufenpyr-ethyl is also practically 

nontoxic to bees on an acute exposure basis (LC,, >25 uglbee). 

Estimated Environmental Concentrations for Birds and Mammals: 

Terrestrial estimated environmental concentrations (EECs) of flufenpyr-ethyl in potential bird 

and mammal food items from single or multiple applications were determined using the ELL-FATE 

model. The EECs from the ELL-FATE model are based on predicted day-0 maximum residues 

following a single application of 1 lb ai/A. These initial concentrations are based on work done by 

Hoerger and Kenaga (1972) as modified by Fletcher et al. (1 994). The ELL-FATE model adjusts 

these predicted maximum residue values by the application rate and annual frequency of application 

for the use sites being modeled and assumes exponential decay following each application of 

pesticide at a rate based on the half-life data provided for the pesticide being modeled. These initial 

adjusted values were based on two maximum single application rates of 0.027 lbs of flufenpyr-ethyl 

per acre and are tabulated in the exposure column of Table 9. The ELL-FATE model and EECs are 

detailed in Appendix VIII. 

Table 9. Initial EECs on Avian and Mammalian Food Items Following Two Applications of Flufenpyrethyl at 0.027 lb ai/A 

Food Items 

Short grass 

Tall grass 

Fruits, pods, seeds, and large insects I 0.74 

Predicted Maximum Flufenpyr-ethyl EECs (ppm) 

11.8 

5.41 

Broadleaflforage plants and insects 

Estimates of Risks to Birds and Mammals 

The toxicity test values (i.e., measurement endpoints) used in the acute and chronic risk 

20 

6.64 I 
quotients are derived from the results of required studies. The EEC, toxicity, and risk quotient values 

are provided below in Table 10. 

Table 10 - Toxicity, Exposure, and Risk Quotient Values of Flufenpyr-ethyl(2 applications of 0.027 lb ai/A, A - - . 

10 days interval, 35 day half-life) 

Mammals-Oral and Reproduction 11 >5000 mgikg I 1463 ppm I 11.8 I cO.01 1 <0.01 I ' Based on ELLFATE model (Detailed in appendix VIII) 

Species 

Northern bobwhite1 Mallard duck-Oral 

BobwhiteIMallard-Dietary 

Northern bobwhite-Reproduction 

Bird and Mammal Risk Assessment Summary 

No acute or chronic LOCs were exceeded for birds and mammals; the risks are believed to be 

negligible. 

Toxicity Exposure 

- (ppm) 

>2250 mglkg 11.8 

>5620 ppm 11.8 

II I I - - 

164 ppm 

Assessment of Risks to Insects 

Risk Quotients 

(RQ) 

<0.01 

<O.O 1 

Toxicity results for the honeybee are used for recommending appropriate label precautions. 

Because flufenpyr-ethyl is practically non-toxic to honeybees (LD,, >25 uglbee) on an acute contact 

basis, precautionary labeling is not required. 

--- 

11.8 

Assessment of Risks to Terrestrial Plants 

0.07 

Toxicit, to Terrestrial Plants 

In toxicity tests, post-emergence plants showed more sensitivity to flufenpyr-ethyl than preemergent plants. With ten plant species (corn, oat, onion, ryegrass, soybean, lettuce, radish, 

cucumber, cabbage, and tomato) applied up to 0.029 lb ai/A, seedling emergence EC2, values ranged 

from >0.029 (corn, oat, ryegrass, soybean, cucumber, and tomato) to 0.012 1bs ai/A (lettuce, shoot 

weight). Seedling emergence NOAEC values ranged from 0.029 (corn, oat, ryegrass, soybean, 

cucumber, and tomato) to 0.0032 lbs ai/A (radish, shoot weight). 

Vegetative vigor EC2, values ranged from >0.029 (corn, oat, ryegrass, and soybean) to 0.00009 

lbs ai/A (tomato, shoot weight), while NOAEC values ranged from 0.029 (corn, oat, ryegrass, and 

soybean) to 0.00004 lbs ai/A (lettuce and tomato, shoot weight). 

The lettuce and tomato EC2, and NOAEC toxicity values are used in the terrestrial plant risk 

assessment since lettuce and tomato were the most sensitive species in the seedling emergence and 

vegetative vigor tests, respectively. 
Estimated Environmental Concentrations for Terrestrial Plants 

Terrestrial plant EECs of flufenpyr-ethyl from single or multiple applications were determined 

using the TerrPlant model (V. 1.0). Details of the TerrPlant model and EECs are presented in Table 

11 and Appendix IX. The EECs from the model are based on the highest single application rate of 

0.027 lb ai/A on sugarcane, the solubility of the pesticide in water (4.1 ppm), and the drift 

characteristics, which vary depending on whether it is a ground or aerial application. The amount 

of flufenpyr-ethyl that runs off is a proportion of the application rate and is assumed to be 1 %, 2%, 

or 5% for water solubility values of 40 ppm, 10-100 ppm, and >I00 ppm, respectively. For 

flufenpyr-ethyl, a runoff value of 1 % is assumed, based on its water solubility limit of 4.1 ppm in 

water. Drift from ground and aerial applications are assumed to be 1 % and 5%, respectively, of the 

application rate. An application efficiency of 60% is assumed for aerial application. In addition to 

considering where plants grow, exposure must be estimated to compare with results from two kinds 

of plant tests - a seedling emergence study and a vegetative vigor study. The seedling emergence 

study involve treating the soil in which seedlings grow, thus exposing the growing plant to the 

pesticide. The vegetative vigor study involves exposing only the foliage of actively growing plants 

off-site to spray drift Both spray drift and runoff are assumed to move off the treated sites . 

Estimates of Risks to Terrestrial Plants 

Table 11. Estimated Environmental Concentrations (EECs in lb ai1A) for NON-GRANULAR formulation 

applications (based on 1 application of 0.027 lbs a.i./acre) 

The toxicity test values (i.e., measurement endpoints) used in the acute and chronic risk 

quotients are derived fi-om the results of required studies. The EEC, toxicity, and risk quotient values 

are provided below in Table 12 for potential runoff, and in Table 13 for potential drift to adjacent 

sites. 

Application 

Ground Unincorporated 

Aerial 

Total Loading to 

Adjacent Areas (EEC = 

Sheet Runoff + Drift) 

0.0005 

0.0015 

Total Loading to Semiaquatic Area (EEC = 

Channelized Runoff + 

Drift) 

0.003 

0.003 

Table 12 - Toxicity, Exposure, and Risk Quotient Values of Flufenpyr ethyl fiom Potential Runoff 

Drift EEC (for ground: 

application rate x 0.01); 

(for aerial: application 

rate x 0.05) 

0.0003 

0.0014 

Species 

Non-Endangered 

Terrestrial plants 

Endangered 

Terrestrial plants 

Seedling 

Emergence 

Toxicity 

(lbs ai/A) 

0.012 

0.0097 

Exposure 

(lbs ai/A) 

see Table 

11 

see Table 

11 

Risk Quotients for Runoff 

(RQ) 

To Adjacent Area To Adjacent Semi-Aquatic 

Area 

aerial 

0.13 

0.16 

ground 

0.05 

0.06 

aerial 

0.25 

0.3 1 

ground 

0.25 

0.3 1 
Table 13 - Toxicity, Ex osure, ar 

, 

Species 

I Non-Endangered Terrestrial 

plants 

I Endangered Terrestrial plants 

* exceeds the LOC for risk to ten 

1 Risk Quotient Values of Flufenp. I 

0.00009 see Table 1 1 

Vegetative 

Vigor 

Toxicity 

(lbs ai/A) 

0.00004 1 see Table 11 

:strial or aquatic plants (RQ 3 1) 

Exposure 

(Ibs ai/A) 

r-ethyl from Potential Drift 

Risk Quotients for Drift 

(RQ) 

To Adjacent Area from Application Area 

aerial ground 

Terrestrial Plant Risk Assessment Summaw 

Considering the proposed uses of flufenpyr-ethyl, the LOC for potential risk to non-endangered 

and endangered terrestrial plants (LOC = 1) is exceeded for both ground and aerial application when 

drift alone is occurring. The EECs do not exceed the seedling emergence EC,, (RQs range from 0.05 

to 0.25 for non-endangered plants) or NOAEC values (RQs range from 0.06 to 0.3 1 for endangered 

plants) from a combination of drift and runoff to dry or semi-aquatic areas. The EECs exceed the 

vegetative vigor EC,, (RQs range from 3 to 15 for non-endangered plants) and NOAEC values (RQs 

range from 7 to 34 for endangered species) from drift to non-target areas. Thus, the proposed use 

of flufenpyr-ethyl on sugarcane and soybean could pose apotential risk to terrestrial plants fiom drift 

alone. 

Currently, EFED does not perform chronic risk assessments for terrestrial plants. Therefore 

no chronic RQ values for terrestrial plants are presented. 

VIII. Risk to Endangered Species 

The Agency's levels of concern for non-target and endangered terrestrial plants are exceeded 

for the proposed use of flufenpyr-ethyl on sugarcane and soybeans. This concern for terrestrial plants 

is based on spray drift to adjacent sites. As indicated in Appendix X, the Tier 1 Aerial Assessment 

Model predicts relatively high end (90th percentile) drift deposition values. Nevertheless, because 

there is a relatively flat slope for the toxicity endpoints, a large no spray zone would be required for 

plants with responses analogous to the three most sensitive dicots. Numbers would be reduced if 

extremely coarse spray was used. 

Nevertheless, at it currently stands, the applicant must provide information on the proximity 

of Federally listed endangered and threatened terrestrial plants to the proposed use sites. This 

requirement may be satisfied in one of three ways: 1) having membership in the FIFRA Endangered 

Species Task Force (Pesticide Registration [PR] Notice 2000-2); 2) citing FIFRA Endangered 

Species Task Force data; or 3) independently producing these data, provided the information is of 

sufficient quality to meet FIFRA requirements. The information will be used by the OPP 

Endangered Species Protection Program to develop recommendations to avoid adverse effects to 

listed species. 
APPENDIX I - SUMMARY OF ENVIRONMENTAL FATE STUDIES 

HYDROLYSIS (161-1) MRID 451 190-19 

The hydrolysis of [pyrida~in~l-6-'~C]flufenpyr-ethyl [V- or S-3 153; ethyl 2-[2-chloro-4-fluoro-5-[5- 

methyl-6-oxo-4-(trifluoromethy1)- 1,6-dihydropyridazin- 1 -yl] phenoxylacetate; radiochemical purity 

>98%], at 0.93-1.13 pg/mL, was studied in sterile aqueous 0.01 M buffer solutions adjusted to pH 

5, 7 and 9. Test solutions were incubated in the dark at 25 * 1°C for up to 30 days, then were 

analyzed for total radioactivity using LSC and for parent compound and its degradates by reversephase HPLC; identifications of [14C]compounds were confirmed using norrnal-phase twodimensional TLC. 

Degradation of [14C]flufenpyr-ethyl increased rapidly with increasing pH. [14C]Flufenpyr-ethyl was 

relatively stable at pH 5 (calculated half-lives of 299-301 days, ? = 0.69), but degraded with halflives of 8.5 days (? = 0.999) at pH 7 and 2.7 hours (? = 0.998) at pH 9. One degradate, S-3153-acid 

[2-[2-chloro-4-fluoro-5-[5-methyl-6-oxo-4-(trifluoromethyl)- 1,6-dihydropyridazin- 1 -yl] 

phenoxylacetic acid], was detected at all three pHs, while a second degradate, S-3 153-acid-4'-COOH 

[2-[2-chloro-4-fluoro-5-[5-methyl-6-oxo-4-(carboxylic acid)- l,6-dihydropyridazin- 1 -yl] 

phenoxylacetic acid], was detected only in the pH 7 and 9 test solutions. 

In the pH 5 solution, [l4C]flufenpyr-ethyl gradually decreased from 92.6-96.5% of the applied 

radioactivity at day 0 posttreatment to 87.9-88.2% at 30 days, while the degradate S-3 153-acid 

increased from 0.5% of the applied at day 0 to 8.247% at 30 days. 

In the pH 7 solution, [14C]flufenpyr-ethyl decreased from 93.5-95.1% of the applied at day 0 to 49.7- 

50.1% at 7 days, 29.7-29.8% at 14 days, 16.9-17.0% at 21 days and was 8.0-8.2% at 30 days. S3 153-acid in the pH 7 solution increased from 0.6-0.7% of the applied at day O to 9.1-9.2% at 1 day, 

22.4-23.1% at 3 days, 41.6-42.2% at 7 days, 79.5-8 1.7% at 21 days, and was 90.0-92.3% at 30 days; 

the degradate S-3 153-acid-4'-COOH was detected at a maximum of 1.4% of the applied at 30 days. 

In the pH 9 solution, [l4C]flufenpyr-ethyl rapidly decreased from 95.2-96.0% of the applied at 0 hour 

to 53.9-55.8% at 2 hours, 3 1.6-32.02% at 4 hours, 17.2-17.7% at 6.5 hours, and was 10.4% at 1 day. 

S-3 1 53-acid in the pH 9 solution increased from 1.2- 1.5% of the applied at 0 hour to 42.8-43.3% at 

2 hours and 98.6-98.7% at 1 day, then gradually decreased to 83.1-84.9% at 7 days, 67.2-72.2% at 

14 days, and was 48.0-5 1 .O% at 30 days. S-3 153-acid-4'-COOH in the pH 9 solution increased from 

50.3% ofthe applied at 4 hours to 6.7-6.8% at 3 days, 15.0-15.1% at 7 days, 24.8-27.3% at 14 days, 

and was 49.8-51.4% at 30 days. 

In all three test solutions (pH 5,7 and 9), unidentified [14C]residues were detected at 14.4% of the 

applied at any sampling interval. Material balances averaged 97.1 * 1.7% (range 93.7-99.7%) of the 

applied at pH 5,97.5 * 2.6% (range 92.4-102.4%) at pH 7, and 99.7 k 2.3% (range 93.4-103.4%) 

at pH 9. 

The phenyl ring was not labeled. However, the chemical structure shows that hydrolysis of the 

phenyl ring is unlikely. 

Degradation pattern of parent and formation and degradation pattern of degradates 
PHOTOLYSIS IN WATER (161-2) MRID 451190-20 

The photolysis of [pyrida~inyl-6-'~C]-labeled and [phenyl-14C]-labeled flufenpyr-ethyl [V- or S3 153; ethyl 2-[2-chloro-4-fluoro-5-[5-methyl-6-oxo-4-(trifluoromethyl)- 1,6-dihydropyridazin- 1 -yl] 

phenoxylacetate; radiochemical purities >97%], at a nominal concentration of 1 ppm, was studied 

in sterile aqueous 0.01 M pH 5 buffer solutions both in the presence and in the absence of a 

photosensitizer (0.6-0.7 ppm humic acids). Test solutions were maintained at 25 k 1°C outdoors 

under natural sunlight in Richmond, California (latitude 37.45" N, longitude 122.26" W), for up to 

1 month. Maximum light intensity ranged from 3,487 to 28,679 pW/cm2 and average daily light 

energy was 1 1.49 W-minute/cm2for the [pyridazinyl-6-14C]1abel-treated solutions (July 24 to August 

25, 1997), and 2,603-27,852 pW/cm2 and 10.53 W-minute/cm2, respectively, for the [phenyl14C]label-treated solutions (September 10 to October 10,1997). Dark controls were also maintained 

for up to 1 month. All samples were analyzed for total radioactivity using LSC and for parent 

compound and its degradates by reverse-phase HPLC; identifications of [14C]compounds were 

confirmed using normal-phase two-dimensional TLC. 

In non-photosensitized solutions, [pyrida~in~l-6-'~C]-labeled and [phenyl-14C]-labeled flufenpyrethyl degraded rapidly under natural sunlipht, with calculated half-lives of 3 and 5 days (8 values 

= 0.98), respectively. Two major degradates, S-3 1 53-4-OH and S-3 1 53-DHPY, and one minor 

degradate, S-3 153-acid-2,4-(OH),, were identified in the irradiated solutions (both labels). One 

additional minor degradate, TFPYR, was identified only in irradiated [pyrida~inyl-6-'~C]label-treated 

solutions. In contrast, in the dark, [14C]flufenpyr-ethyl only slightly degraded in similar solutions 

incubated . Two minor degradates, S-3153-acid [2-[2-chloro-4-fluoro-5-[5-methyl-6-oxo-4- 

(trifluoromethy1)- l,6-dihydropyridazin-1 -yl] phenoxylacetic acid] and S-3 1 53 - 1 -OH, were identified 

in the dark control solutions (both labels). 

In non-photosensitized irradiated [pyridazinyl-6-14C]1abel-treated solutions, [14C]flufenpyr-ethyl 

decreased from 97.6-97.8% of the applied radioactivity at day 0 posttreatment to 58.4-61.5% at 2 

days, 16.5-21.2% at 7 days, 3.4-4.0% at 11 days, and was 11.0% by 20 days. S-3153-4-OH was 

detected at a maximum 40.3% ofthe applied at 1 1 days posttreatment and was 19.1-24.6% at 32 days 

(final sampling interval). S-3 153-DHPY was detected at a maximum 22.7% of the applied at 7 days 

and was 6.8-14.5% at 32 days. S-3 153-acid-2,4-(OH), was detected at amaximum 12.6% at 32 days 

and TFPYR was detected at a maximum 1 1.2% at 20 days. Unidentified [14C]residues eluting at the 

solvent front (3-5 minutes) and combined random peaks were detected at maximums of 14.8%of the 

applied at 20 days and 35.7% of the applied at 32 days, respectively; individual components were 

each 4% of the applied. At 32 days posttreatment, 14C02 and [14C]organic volatiles totaled 4.4 and 

2.2% of the applied, respectively. 

In non-photosensitized irradiated [phenyl-14C]label-treated solutions, [14C]flufenpyr-ethyl decreased 

from 93.0-94.3% of the applied at day 0 posttreatment to 68.7-69.4% at 2 days, 40.5-41.1% at 5 

days, 18.8-22.5% at 9 days, 4.7-10.5% at 15 days, and was 1.4-1.5% at 30 days. S-3153-4-OH was 

detected at a maximum 40.8% ofthe applied at 15 days posttreatment and was 3 1.6-34.3'76 at 30 days 

(final sampling interval). S-3 153-DHPY was detected at a maximum 21.2% of the applied at 15 

days and was 1 1.6-1 5.3% at 30 days. S-3 153-acid-2,4-(OH), was detected at a maximum 8.8% at 

30 days. Unidentified [14C]residues eluting at the solvent front (3-5 minutes) and combined random 

peaks were detected at maximums of 10.7%of the applied at 15 days and 22.9% of the applied at 30 
days, respectively; individual components were each 27% of the applied. At 30 days posttreatment, 

14C0, and [14C]organic volatiles totaled 14.2 and 0.2% of the applied, respectively. 

In non-photosensitized dark control solutions at 1 month posttreatment, [14C]flufenpyr-ethy1 

comprised 79.5-84.3% of the applied in [pyridazinyl-6-14C]1abel-treated solutions and 80.9-89.8% 

in [phenyl-14C]label-treated solutions. At 1 month posttreatment for both labels, the degradates S3 153-acid, S-3153-1-OH, and S-3153-4-OH were detected at 4.2-5.6%, ~6.2%~ and <7.8% of the 

applied, respectively, and 14C0, and organic volatiles were < 0.9% and 20.1 %, respectively. 

Material balances ranged from 93.1 - 102.2 % for the irradiated solutions and 93.6 - 10 1.3% for the 

dark control solutions, both labels. 

In photosensitized solutions, [pyrida~in~l-6-'~C]-labeled and [phenyl-14C]-labeled flufenpyr-ethyl 

degraded under sunlight in a similar manner as the non-photosensitized solutions, with calculated 

half-lives of 3 and 4 days (I? values = 0.99). [14C]Flufenpyr-ethyl only slightly degraded in 

photosensitized solutions incubated in the dark. Degradate profiles in the irradiated and dark control 

photosensitized solutions (both labels) were similar to the non-photosensitized solutions. However, 

there was an approximate 2-fold increase in volatilized 14C0, in the irradiated photosensitized 

solutions; 14C0, totaled 1 1.2 and 24.9% of the applied radioactivity for the irradiated Ipyridazinyl-6- 

14C]label- and [phenyl-14C]1abel-treated photosensitized solutions, respectively, at 1 month 

posttreatment. Material balances ranged from 95.0 - 106.9 % for the irradiated solutions and 97.5 - 

106.7% for the dark control solutions, both labels. 

Calculated quantum yields for non-photosensitized [pyrida~inyl-6-'~C]-labeled and [phenyl-'4C]- 

labeled flufenpyr-ethyl in pH 5 buffer were 1.4 1 x 1 O4 and 9.80 x lo-', respectively. Quantum yields 

for photosensitized [pyridazinyl-6-14C]-labeled and [phenyl-14C]-labeled flufenpyr-ethyl in pH 5 

buffer were 1.36 x loe4 and 1.12 x respectively. Based on the average quantum yield of 1.20 

x (both labels), the predicted half-life of flufenpyr-ethyl in pH 5 buffer at 40°N latitude during 

winter was calculated as 4.8 days. 
PHOTOLYSIS IN SOIL (161-3) MRID 451 190-21 

The photolysis of [pyridazinyl-6-'4C]-labeled and [phenyl-'4C]-labeled flufenpyr-ethyl ( 

radiochemical purities 296%) was studied on sandy loam and loamy sand soils, respectively, at a 

nominal concentration of 0.4 ppm. Samples were maintained at 25 * 1 "C and 75% of field moisture 

capacity outdoors under natural sunlight in Richmond, California (latitude 37.45" N, longitude 

122.26" W), for up to 30 days. Maximum light intensities ranged from 4,643-27,575 and 4,188- 

28,472 pW/cm2 and average daily light energies were 11.37 and 9.45 W-minute/cm2 for the 

[pyrida~inyl-6-'~C]flufenpyr-eth~l-treated soil samples (August 19-22,1997 and April 27 to May 27, 

1998, respectively), and 24,036-25,692 pW/cm2 and 10.75 W-minute/cm2, respectively, for the 

[phenyl-14C]flufenpyr-ethyl-treated soil samples (August 10 to September 9, 1998). Dark controls 

were maintained alongside irradiated soils for up to 30 days. All samples were analyzed for total 

radioactivity using LSC and for parent compound and its degradates by reverse-phase HPLC; 

identifications of ['4C]compounds were confirmed using normal-phase two-dimensional TLC. 

Volatiles were collected at all sampling intervals after time 0. All data, reported as percentages of 

the applied, represent percentages of the actual application. 

[Pyridazinyl-6-'4C]-labeled and [phenyl-'4C]-labeled flufenpyr-ethyl degraded rapidly on both 

irradiated and dark control soils, with observed half-lives of 4-7 hours. The degradation of 

['4C]flufenpyr-ethyl on irradiated soils was bi-phasic with initial half-lives of 5.5-6.7 hours (3 = 

0.91-0.97; 0- to 7-hour data) and secondary half-lives of 32-40 days (? = 0.23-0.80; 1- to 30-day 

data). Two major degradates, S-3 153-acid and S-3 153-1 -OH, and one minor degradate, S-3 153- 1- 

OCH,, were identified in irradiated soil extracts (both labels). One additional degradate, TFPYR, 

was identified only in irradiated [pyrida~inyl-6-'~CIlabel-treated soil extracts. In dark control soil 

extracts, S-3 153-acid was the major degradate detected (both labels), and S-3 153-1 -OH was detected 

as a minor degradate only in [phenyl-'4C]label-treated soil extracts. Volatilized 14C02 averaged 3.5% 

and 23.5% of the applied radioactivity for the irradiated [pyridazinyl-6-'4C]label- and [phenyl14C]label-treated soil samples, respectively, at 30 days posttreatment. In the dark controls, volatilized 

I4Co2 was 4% at 30 days posttreatment. Material balances (irradiated and dark controls, both 

labels) averaged 97.3 * 4.4% (range 87.3-105.9%, n = 86) of the applied radioactivity. 

In extracts from irradiated soil, [14C]flufenpyr-ethyl decreased from 90.9-97.0% of the applied 

radioactivity at time 0 posttreatment to 48.3-55.5% at 4 hours, and was 9.3-10.7% at 30 days. S3 153-acid was detected at a maximum at 1 day posttreatment for both labels at 50.1-77.9% of the 

applied and degraded quickly to 5.4-19.9% at 30 days. S-3153-1-OH, formed by hydrolysis of S3 153-acid in both labels, was detected at a maximum 15.8-1 8.1% of the applied at 9 days and was 

8.0-14.1% at 30 days. S-3 153-1-OCH, was 15.4% at any sampling interval. TFPYR, the cleavage 

product in the [pyrida~iny1-6-'~C]label-treated soil extracts was detected at a maximum 22.8-28.3% 

of the applied at 30 days. Unidentified [14C]residues comprised a maximum 21.5-25.3% of the 

applied at 30 days and consisted of numerous components, each <6.3% of the applied. Unextractable 

[14C]residues were 8.2-1 1.2% ofthe applied at 30 days; 3.5-1 0.4% ofthe applied was associated with 

the fulvic acid fraction, 1.2-2.1 % was humic acid, and 13.6% was humin. 

In extracts fiom dark control soil, [14C]flufenpyr-ethyl decreased to 50.6-53.6% at 4 hours and was 

12.2-14.3% at 30 days. S-3 153-acid increased to 85.7-95.4% ofthe applied by 9 days then gradually 

decreased to 80.4-8 1.4% at 30 days in [pyridazinyl-6-'4C]1abel-treated samples, while it was detected 
at a maximum 71.7-78.7% at 3-30 days in [phenyl-14C]label-treated samples. S-3153-1-OH was 

detected only in [phenyl-14C]label-treated samples at 11.4% of the applied. Unidentified 

[14C]residues comprised 14.8% of the applied. Unextractable [14C]residues were 4.3-7.3% of the 

applied at 30 days posttreatment. 

Due to the rapid microbial degradation of S-3153 on soil (t '/z < 7 hours), it is not certain if 

photolysis contributes to the degradation of flufenpyr-ethyl on soils. However the results indicate 

that photolysis is an important dissipation route for the primary degradate, S-3 153-acid, under the 

conditions tested. The half-life of S-3 153-acid in irradiated samples was calculated as 16.3 days and 

10.5 days, in pyridazinyl and phenyl samples, respectively, by assigning the concentrations of S3 153-acid detected at day 1 posttreatment as time zero values. 

AEROBIC SOIL METABOLISM (161-4) MRID 451190-22 

[Pyrida~in~1-6-'~C]flufen~yr-ethyl (radiochemical purity 98.8%), at 0.06 ppm, degraded with an halflive of approximately 1 hour in sandy loam soil moistened to 75% of the field moisture capacity and 

incubated in the dark at 25OC for 365 days. The degradation of S-3153 in sandy loam soil was 

observed to be biphasic; flufenpyr-ethyl comprised 4% of the applied at 1 day posttreatment, then 

declined slowly to 0.9-1.2% at 365 days. Using linear regression of log transformed concentrations, 

the half-life in the entire system was calculated to be 1.5 hours (? = ) in the entire system, based 

on 0-4 hours data; and 97.4 days (9 = 0.4170) based on 0-365 days data . Using a non linear 

regression of non transformed data, the half-life is 1.2 hours (? = 0.9778) in the entire system. 

Four degradates were identified: S-3 153-acid (maximum 83.5% at day 1 posttreatment), S-3 153-1 - 

OH (maximum 14.1% at day 91), S-3153-1-OCH, (maximum 53.2% at day 177), and S-3153-1- 

OCH,-5'-CH,OH (maximum 17.7% at day 365). 

It was proposed that flufenpyr-ethyl degrades rapidly in soil to S-3 153-acid, which was formed by 

hydrolysis of the ester moiety. S-3 153-acid subsequently degraded to S-3 153- 1 -OH via oxidative 

cleavage of the acid group to phenol, which in turn methylated to form S-3 153-1-OCH,. S-3 153-1 - 

OCH,-5'-CH,OH was formed by hydroxylation of the methyl group in the 5' position of the pyridine 

ring of S-3 153-1 -OCH,. The half-life of S-3 153-acid ( t ?4 = 38.5 days) was calculated assuming 

that the concentration of S-3153-acid detected at day 1 posttreatment as the time zero value. 

Likewise, the half-life of S-3 153-1 -OH (t ?4 = 7.1 days) was calculated using day 59 as the time zero 

value. The half-life of S-3 153-1-OCH, (t ?4 = 47.6 days) was calculated using day 177 as the time 

zero value. The half-life calculations were based on non linear regression of non transformed data. 

Flufenpyr-ethyl was 95.0-96.5% of the applied at time 0,50.2-50.3% at 1 hour posttreatment, 16.1- 

19.7% at 4 hours, 5.4-6.0% at 1 day, and 0.9- 1.4% at 365 days. Using linear regression calculations 

with log-converted data, the half-life is 97.6 days (? = 0.417) for 0 - 365 days data, 210 days (9 = 

0.8151) for 1 - 365 days, and 1.7 hours (3 = 0.9566) for 0 - 4 hours. None of these calculations 

accurately reflect the curvilinear nature of the whole data set; 

S-3 153-acid plus S-3 1 53-1-OCH,-5'-CH,OH, which were not differentiated by HPLC, averaged a 

maximum of 83.5% ofthe applied at 1 day posttreatment, 57.5-58.9% at 29 days, and varied between 
15.7 and 30.9% at 59 through 365 days. TLC analysis indicated that S-3 153-acid decreased fkom 

30.9% of the applied at 59 days posttreatment to 6.4% at 365 days (fkom 100.0% to 26.2% of the 

mixture), and S-3153-1-OCH,-5'-CH20H increased from 0% of the applied at 59 days to 18.7% at 

365 days. S-3 153-1-OCH, averaged a maximum of 53.2% of the applied at 177 days posttreatment 

and decreased to 24.1% at 269 days and 11.2% at 365 days. S-3 153-1-OH averaged a maximum of 

14.1% of the applied at 91 days posttreatment, 4.4-5.2% at 91-177 days, and 2.5% at 365 days. 

Unknown 1 (R,approximately 14 minutes), which was thought to be derived by oxidation of S-3 153- 

1 -OCH,-5'-CH,OH, was initially detected at 177 days posttreatment and averaged a maximum of 

13.9% of the applied at 365 days. Unidentified [14C]residues, each present at <4.2% of the applied, 

increased to 20.6% of the applied at 365 days posttreatment. At 365 days posttreatment, unextracted 

['4C]residues totaled amaximum 20.7-21.3% of the applied, organic ['4C]volatiles totaled 0.1 %, and 

I4CO2 totaled 6.7-8.1%. 

Material balances ranged from 93.1 - 1 02.9% of the applied throughout the study with no pattern of 

decline. 

ANAEROBIC AQUATIC METABOLISM (161-4) MRID 451190-23 

[Pyrida~in~l-6-'~C]flufen~yr-ethyl (radiochemical purity 99. I%), at 0.06 ppm, degraded with an 

observed initial half-life of less than 1 hour in anaerobic (flooded plus nitrogen atmosphere) clay 

loam sediment that was incubated in the dark at 25OC for 365 days. Approximately 90% had 

dissipated by 4 hours posttreatment and <99% by 1 day. Two major degradates were identified: S3 153-acid (maximum 81.5% at day 1 posttreatment) and S-3 153-1-OH (maximum 84.4% at day 

185). 

It was proposed that flufenpyr-ethyl degrades rapidly to S-3 153-acid, which in turn degrades to S3 153- 1 -OH. S-3 153- 1 -OH is relatively persistent under anaerobic conditions. Since the conversion 

of flufenpyr-ethyl to the acid form was nearly complete by day 1, the half-life of S-3 153-acid ( t ?4 

2 3 days) was calculated assuming that the concentration of S-3153-acid detected at day 1 

posttreatment as time zero values. The half-life of S-3153-OH (extrapolated t% = 866 days) was 

calculated using the time point where the highest percent of this degradate was observed (1 85 days) 

as the time zero. 

In the total sediment/water system, flufenpyr-ethyl was 70.5-82.1% of the applied at time 0,27.2- 

36.7% at 1 hour posttreatment, 10.0- 1 1.4% at 4 hours, 0.5-0.8% at 1 day, and 0.0% at and after 3 

days. S-3 153-acid was 5.5-1 8.4% ofthe applied at time 0,46.6-61.1% at 1 hour posttreatment, 75.8- 

81.5% at 1 day, 52.1-53.7% at 3 days, 19.8-24.2% at 7 days, and was not detected at and after 30 

days. S-3 153-1 -OH was 3 1.1-34.2% of the applied at 3 days posttreatment, 78.5-79.3% at 30 days, 

a maximum 84.0-84.4% at 185 days, and 67.7-77.5% at 365 days. At 365 days posttreatment, an 

HPLC peak at 14-17 minutes and "others" contained 2.1-7.0 and 4.5-7.8% of the applied, 

respectively. At 3 65 days posttreatment, unextracted [14C]residues totaled a maximum 15.1 - 15.5% 

of the applied, organic [14C]volatiles were below detection levels, and 14C0, totaled 0.4-0.7%. The 

distribution ratio of [14C]residues between the water and sediment phases was approximately 7:2 at 

time 0,6:4 at 1 day posttreatment, 3:7 at 7 days, and 1:4 at and after 30 days. 
Material balances ranged from 93.7-100.1% of the applied (mean 96.6 h 1.8%) with no pattern of 

decline. 

SOIL ADSORPTION/DESORPTION (163-1) MRID 451191-01 

Three degradates of flufenpyr-ethyl, S-3 153 Acid, S-3 153-1-OH and S-3 153-1-OCH, were 

determined to be mobile in Ockley sandy loam (1.1 %OC; 6.6 pH), Cecil sandy clay (0.81 %OC; 5.1 

pH), Bosket sandy loam (0.35 %OC; 6.4 pH); and Drummer-Flanagan loam soil (1.8 %OC; 5.6 pH). 

The soils were equilibrated with water or aqueous 0.01M calcium chloride solution slurries in the 

dark at room temperature for 24 hours. The study was conducted at nominal concentrations of 1.0, 

0.2,0.04, and 0.008 ppm. The soil:solution ratios were l:l, 1:3, or 1 :5, depending on test substance 

and soil type. The Organic Carbon Normalized soillwater partitioning coefficients for adsorption 

(KO,-,,,) ranged fi-om 19 - 73 mL/g for S-3 153 Acid, 149 - 216 mL/g for S-3 153-1-OH, and 210 - 284 

mL/g for S-3 153-1 -OCH,. 

Based on HPLC adsorption behavior, it was predicted that flufenpyr-ethyl would have a KO, of 41 5 

mL/g; the mobility could not be determined experimentally because flufenpyr-ethyl was unstable in 

solution. This indicated that flufenpyr-ethyl may be less mobile than its major degradates. 

[14C]S-3153Acid [2-chloro-4-fluoro-5-(5-methyl-6-oxo-4-trifluoromethyl- 1,6-dihydropyridazin- 1 -yl) 

phenoxy)acetic acid; radiochemical, purity >97%]: Freundlich adsorption K,,,, values were 0.21 

mLlg for the Ockley sandy loam soil, 0.59 mL/g for the Cecil sandy clay soil, and 0.74 mL1g for the 

Drummer-Flanagan loam soil. The Organic Carbon Normalized soillwater partitioning coefficients 

for adsorption (KO,-,) were 19 (Ockley sandy loam), 73 (Cecil sandy clay), 41 (Drummer-Flanagan 

loam soil), and 24 (Bosket sandy loam; preliminary test); lln values ranged from 0.92-0.96. The 

coefficient of determination (8) values for K, vs. percent organic matter, Kd vs. pH, and K, vs. 

percent clay content were 0.91, 0.46, and 0.29 respectively. Following two 24-hour desorption 

periods, K,,,, values were 2.91 for sandy loam soil, 0.67 for sandy clay soil, and 0.8 1 for loam soil; 

values were 264 for the sandy loam soil, 83 for the sandy clay soil, and 45 for the loam soil; 

l/n values ranged from 0.89- 1.04. Material balances ranged from 102- 1 16% of the applied. Due 

to the low adsorption to the Bosket sandy loam (0.6 %OM), this soil was not used in the definitive 

study; the adsorption Kd and KO, values estimated from the preliminary study were 0.08 mL/g and 

24 mLlg, respectively. 

[14C]S-3153-1-OH, [2-(4-chloro-2-fluoro-5-hydroxy)phenyl-4-methyl-5-trifluoromethyl-2,3- 

dihydropyridazin-3-one; radiochemical, purity 97%] : Freundlich adsorption K, values were 0.75 for 

the Bosket sandy loam soil, 1.64 for the Ockley sandy loam soil, 1.29 for the Cecil sandy clay soil, 

and 3.65 for the Drummer-Flanagan loam soil. The respective KO, values were 216, 149, 159, and 

203 mL/g, with l/n values ranging fi-om 0.78-0.90. The coefficient of determination (?) values for 

K, vs. percent organic matter, K, vs. pH, and K, vs. percent clay content were 0.46,O. 13, and 0.10 

respectively. Following two 24-hour desorption periods, K, values were 3.84-3.87 for the sandy 

loam soils, 1.86 for the sandy clay soil, and 6.94 mLlg for the loam soil; KO, values were 349-1 1 11 

for the sandy loam soils, 230 for the sandy clay soil, and 386 mLlg for the loam soil; l/n values 

ranged from 0.83 - 0.89. Material balances ranged fi-om 103-1 14% of the applied. 
[14C]S-3153-1-OCH3 [2-(4-chloro-2-fluoro-5-methoxy)phenyl-4-methyl-5-trifluoromethyl-2,3- 

dihydropyridazin-3-one; radiochemical, purity >99%]: Freundlich adsorption K, values were 0.99 

for the Bosket sandy loam soil, 2.3 1 for the Ockley sandy loam soil, 1.83 for the Cecil sandy clay 

soil, and 4.47 mL/g for the Drummer-Flanagan loam soil; Respective KO, values were 284,210,226, 

and 248 mL/g with l/n values ranged from 0.92-0.90. Reviewer-calculated coefficient of 

determination (r2) values for K, vs. percent organic matter, K, vs. pH, and K, vs. percent clay content 

were 0.38,O. 15, and 0.10 respectively. Following two 24-hour desorption periods, K, values were 

5.46-7.94 for sandy loam soils, 8.57 for sandy clay soil, and 9.61 mL/g for loam soil; KO, values were 

72 1 - 1 570 for the sandy loam soils, 1055 for the sandy clay soil, and 53 5 mL/g for the loam soil; l/n 

values ranged from 0.89-1.08. Material balances ranged from 96-107% of the applied. 

TERRESTRIAL FIELD DISSIPATION (164-1) 

MRID 451191-02 

The terrestrial field dissipation of phenyl ring-labeled flufenpyr-ethyl, formulated as a wettable 

powder, was conducted on lysimeter-enclosed plots in Kilbourne, Franklin County, Ohio at a rate 

equivalent to 28.82 g ai/A. Test soils were labeled flufenpyr-ethyl was used because of the low 

application rate and also t\o facilitate the detection and monitoring of anticipated low level residues. 

Following one application, flufenpyr-ethyl dissipated with a half-life of <2 hours. Soil samples were 

analyzed for flufenpyr-ethyl and twelve potential degradates, of which the following seven were 

detected: 

S-3 153Acid [[2-chloro-4-fluoro-5-(5-methyl-6-oxo-4-trifluoromethyl-1,6-dihydropyridazin-1- 

yl)phenoxy] acetic acid)], 

S-3 1 53-DHPY [ethyl [2-chloro-4-fluoro-5-[(2-hydroxy-4-methyl-5-oxo-3-~fluoromethyl-2,5- 

dihydro- 1 H-pyrrol- 1 -yl)amino]phenoxy]acetate], 

S-3 153-4-OH [ethyl[2-chloro-4-hydroxy-5-(5-methyl-6-oxo-4-trifluoromethy1- 1,6- 

dihydropyridazin- 1 -yl)phenoxy]acetate], and 

Residue data are the means of duplicates. Flufenpyr-ethyl was initially present in the 0- to 3-inch 

depth at 0.090 ppm, was 0.0 10-0.0 14 ppm from 2 hours to 2 days, and was detected at ~0.00 1 ppm 

following 2 days posttreatment. S-3 153Acid was present in the 0- to 3-inch depth at a maximum of 
0.030 pprn at 7 hours, was 0.0 12-0.0 16 pprn from 1 to 5 days, decreased to 0.007 pprn by 13 days, 

and was last detected at 0.001 pprn at 124 days posttreatment. Maximum and final detections of S3 153 Acid and the other six degradates in the O- to 3-inch depth were as follows: 

No res 

Degradate I Calculated half-life1 

I 

S-3 153-Acid 1 day 

S-3 153-1-OCH, 250 days 

I 

S-3 153-DHPY 1 day 

S-3 153-4-OH Not determined 

S-3 153- 1-OCH,- Not determined 

5'CH,OH 

lues were detected in the 3- to 6-inch ( 

Maximum detection (pprn) I Final detection (pprn) 

0.017 (13 days) 0.006 (363 days; last 

0.0 10 (7 hours and 2 days) 0.0 10 (2 days) 

0.006 (2 hours and 1-2 0.001 (170 days) 

days) 

0.007 (2 days) 0.007 (2 days) 

0.001 (91 and 170-300 0.001 (300 days) 

days) 

epth at >0.002 pprn with the exception of S-3 153-1 - 

OCH,, which was detected at 0.003-0.004 ppm at 13, 58, 9lYand 170 days posttreatment. Total 

[14C]residues were <0.0011 pprn at all sampling intervals below the 3- to 6-inch depth. 

Radioactivity in the leachate and run-off water was not reported. Test soil is classified by the 

National Resources Conservation Service (NRCS) as an Ockley silt loam, and has a slope of less 

than 1%. 

MRID 451191-03 & 451191-21 

Flufenpyr-ethyl, as the formulation S-3 153 50 WP), was broadcast once at anominal application rate 

of 24.6 g a.i./A onto a bareground plot of Grangeville loamy sand soil in Madera County, California. 

Following the application, the calculated DT,, was 0.9 days for flufenpyr-ethyl and 4 days for S-3 153 

Acid. Data are reported as the averages of three replicates unless otherwise stated. Soil samples 

were analyzed for flufenpyr-ethyl and the degradates, 

S-3 153 Acid [[2-chloro-4-fluoro-5-(5-methyl-6-oxo-4-~fluoromethyl- 1,6-dihydropyridazin- 1 - 

y1)phenoxylacetic acid], 

S-3 153- 1 -OH [2-(4-chloro-2-fluoro-5-hydroxy)-phenyl-4-methyl-5-trifluoromethyl-2,3- 

dihydropyridazin-3-one], and 

Residue data were not corrected for soil moisture content or method recovery. In the 0- to 3-inch 

soil depth, flufenpyr-ethyl was present at a maximum of 0.008 pprn immediately posttreatment, 

decreased to 0.005 pprn by 1 day, and was last detected at 0.003 pprn at 3 days posttreatment. S3153 Acid was present in the O- to 3-inch soil depth at a maximum of 0.027 pprn immediately 
posttreatment, decreased to 0.012 pprn by 3 days and 0.008 pprn by 7 days, and was last detected at 

0.002 pprn (1 of 3 replicates) at 14 days posttreatment. S-3 153-1-OCH, was detected at 50.004 pprn 

(29 days), and S-3153-1-OH was not detected at any sampling interval. Flufenpyr-ethyl and the 

degradates analyzed for were not detected below the 3-inch soil depth. 

MRID 451191-04 & 451191-21 

Flufenpyr-ethyl, as the formulation S-3 153 50 WP) was broadcast once at a nominal application rate 

of 24.5 g a.i./A onto a bareground plot of Drummer silt loam soil in Champaign County, Illinois. 

Following the application, the registrant-calculated DT,, was 2.0 days for flufenpyr-ethyl and 14.4 

days for S-3 153 Acid. The data are reported as the averages of three replicates unless otherwise 

stated. Soil samples were analyzed for flufenpyr-ethyl and the degradates, 

S-3 1 53 Acid [[2-chloro-4-fluoro-5-(5-methyl-6-oxo-4-trifluoromethyl- 1,6-dihydropyridazin- 1 - 

y1)phenoxylacetic acid], 

S-3 153- 1 -OH [2-(4-chloro-2-fluoro-5-hydroxy)-phenyl-4-methyl-5-trifluoromethyl-2,3- 

dihydropyridazin-3 -one], and 

Residue data were not corrected for soil moisture content or method recovery. In the 0- to 3-inch 

soil depth, flufenpyr-ethyl was present at a maximum of 0.028 pprn immediately posttreatment, 

decreased to 0.016 pprn by 1 day, and was last detected at 0.014 pprn at 3 days posttreatment. S3 153 Acid was present in the O- to 3-inch soil depth at 0.008-0.01 8 pprn from O to 14 days, decreased 

to 0.005 pprn by 28 days, and was last detected at 0.003 pprn at 43 days posttreatment. S-3 153-1- 

OCH, was detected at 0.009-0.012 pprn from 43 to 367 days and decreased to 0.006 pprn by 445 

days posttreatment. S-3153-1-OH was detected at 10.005 pprn (9 and 14 days) at all sampling 

intervals. Flufenpyr-ethyl and the degradates analyzed for were generally not detected below the 3- 

inch soil depth. 
Appendix I1 - Chemical Structures and Proposed Degradation Pathways 

Flufenpyr-ethyl 

Chemical Name: (ethyl 2-[2-chloro-4-fluoro-5-[5-methyl-6-oxo-4-(trifluoromethyl)- 1,6-dihydropyridazin- 1- 

yllphenoxylacetate 

Synonyms: [Phenyl-14C]S-3 135, V-3 153 

Degradates 

[Phenyl-14C]S-3153Acid 

Chemical Name: [2-chloro-4-fluoro-5-(5-methyl-6-oxo-4-~1- 1,6-dihydropyridazin- 1 -yl)phenoxy]acetic acid 

Synonyms: S-3 153Acid, M-1 
[Phenyl-14C]S-3153-1-OH 

Chemical Name: 2-(4-chloro-2-fluoro-5-hy&oxy)phenyl-4-methyl-5-ifluoromethyl-2,3-dihy&opyridazin-3-one 

Synonvms: S-3 153-1-OH, M-5 

[Phenyl-14C]S-3153-1-OCH, 

Chemical Name: 2-(4-chloro-2-fluoro-5-methoxy)phenyl-4-methyl-5-@ifluoromethyl-2,3-dihy&op~idazh-3-one 

Synonyms: S-3 153-1-OCH,, M-9 
S-3 153-DHPY 

Chemical Name: Ethyl [2-chloro-4-fluoro-5[(2-hydroxy-4-methyl-5-oxo-3-trifluoromethyl-2,5-dyo-lH-pyrrol-lyl)amino]phenoxy]acetate 
S-3153-4-OH 

Chemical Name: Ethyl[2-chloro-4-hydroxy-5-(5-methyl-6-oxo-4-trifluoromethyl-1,6-dihydropyridazin-1- 

y1)phenoxylacetate 
S-3153-acid-4'-COOH 

ChemicalName: [2-[2-chloro-4-fluoro-5-[5-methyl-6-oxo-4-(carboxylic acid)-l,6-dihydropyridazin-1-yl]phenoxy]acetic 

acid] 

TFPYR 
Proposed Hydrolysis Pathway 
Proposed Aqueous Photolysis Pathway 
Proposed Metabolic Pathway in Aerobic Soil 
Proposed Metabolic Pathway in Anaerobic Aquatic Soil 
APPENDIX I11 - Aquatic Exposure Assessment 

U. S. ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, DC 20460 

OFFICE OF 

PREVENTION, PESTICIDES 

AND TOXIC SUBSTANCES 

Date: August 08,2003 

PC Code 108853 

DP Barcode: D268736 

MEMORANDUM 

SUBJECT: Tier 1 Water Resources Assessment of Flufenfyr ethyl and its degradates 

PROM: Thuy L. Nguyen, Chemist 

ERB 111, Environmental Fate and Effects Division (7507C) 

THRU: Ben Smith, Branch Chief 

Stephanie Syslo, RAPL 

ERB 111, Environmental Fate and Effects Division (7507C) 

TO: Joanne Miller 

Registration Division (7505C) 

CC: Jennifer-R Tyler 

Health Effects Division (7509C) 

The Environmental Fate and Effects Division has reviewed the proposed new uses for flufenpyr 

ethyl on soybean, sugarcane, and field corn. This memo presents the Tier 1 Water Resources 

Assessment for flufenpyr ethyl and for three of flufenpyr ethyl's major soil degradates, S-3 153-acid, 

S-3153-1-OH, and S-3153-1-OCH,. 

For human health exposure assessment, drinking water estimated concentrations (DWEC) for 

surface and ground water are calculated using FIRST (EQPA index Reservoir Screening Tool) and 

SCI-GROW (Screening Concentration in &und_water), respectively. Results for parent flufenpyr 

ethyl are reported in Table 1, for all three crops. Results for the degradates are reported in Table 

2, for sugarcane crop only, since with the high Percent Cropped Area (PCA) factor and the high 

maximum annual application rate, the DWECs for sugarcane represent the most conservative values 

amongst those of the proposed uses. 

For ecolonical risk assessment, estimated environmental concentrations (EEC) for surface 

water are calculated using GENEEC2 (GENeric Estimated Environmental Concentration). Results 

are reported in Table 3 on sugarcane for parent and its 2 major degradates. These results represent 

the most conservative EEC values amongst those of the proposed uses. 
I Annual Average (chronic) 0.004 ppb I 0.002 ppb I 0.001 ppb I 

Table 1 - Flufenpw ethyl DWECs for Human Health Assessment 

Ground Water: Acute and Chronic I <0.01 ppb I <0.01 ppb I <0.01 ppb I 

Surface Water: Peak (acute) 

Table 2 - Flufenpw ethyl degradates DWECs- based on Sugarcane crop 

S-3153-acid S-3153-OH S-3153-1-OCH, 

Surface Water: Peak (acute) 3.6 ppb 0.35 ppb 1.5 ppb I I I Annual Average (chronic) I 1.5 ppb I 0.04 ppb I 0.49 ppb I 

Field corn 

0.024 ppb 

Sugarcane 

0.161 ppb 

I Ground Water: Acute and Chronic 1 0.04~~b 1 <0.01 DD~ 1 <0.01 ppb I 

Soybean 

0.076 ppb 

For flufenpyr ethyl, the water concentrations were based on sugarcane and soybean (2 

applications per year at 0.027 lb ai/A each, with a 10-day retreatment interval between application) 

and on field corn (2 applications per year at 0.0 19 lb ai/A each, with a 10-day retreatment interval 

between application. For sugarcane and soybean, although both aerial and ground application are 

permitted, aerial application was simulated to derive at the highest level of surface water 

contamination. For field corn, only ground application is permitted. Note that, even though 

sugarcane and soybean have the same maximum annual application rate, sugarcane has much higher 

surface DWEC values partially due to its high default PCA value. 

For the degradates, only the sugarcane values were reported, as they are the most conservative 

estimates, also due to the high PCA value. 

Table 3 - Surface Water EECs for Eco1og;ical Risk Assessment, based on Sugarcane 

b I I I I i 

The EECs listed in Table 3 were based on sugarcane, since it has the highest maximum 

allowable rate (2 applications per year at 0.027 lb ai/A each, with a 10-day retreatment interval 

between application). Aerial application was also assumed for parent flufenpyr ethyl in order to 

predict the highest level of surface water contamination. For the degradates, although aerial 

application was used, no drift was assigned since those degradates were formed on soils. 

Furthermore, no PCA adjustment was required for these surface water EECs. 

Flufenpyr Ethyl 

S-3153-acid 

S-3153-1-OH 

Peak 

0.279 ppb 

2.19 ppb 

0.215 ppb 

Average 

4-day 

0.270 ppb 

2.19 ppb 

0.212 ppb 

Average 

----- 21-day 

0.191 ppb 

2.15 ppb 

0.196 ppb 

Average 

60-day 

0.101 ppb 

2.08 ppb 

0.165 ppb 

Average 

90-day 

0.070 ppb 

2.03 ppb 

0.145 ppb a 
Table 4 lists the proposed use patterns associated with this surface and ground water resource 

assessment. 

PhysicaYChemical Properties and Environmental Fate Summary 

Table 4 - 

Uses 

F~eld corn 

Sugarcane 

Soybeans 

Flufenpyr ethyl is an odorless off-white powder. Based on a solubility in water of 4.1 mg/L 

at 20 "C, a vapor pressure of 3.8 x Pa at 20°C, and a melting point of 100 - 10l°C, EFED 

predicts that volatilization may not be a significant dissipative pathway for flufenpyr ethyl. A Log 

Po, of 2.99 h 0.05 also indicates the bioaccumulation potential of this chemical in fish could be 

negligible. 

Laboratory studies show that flufenpyr ethyl does not persist in the environment, neither in 

water nor in soil systems. Photolysis in water is fairly rapid (t ?h < 5 days) and the rate of hydrolysis 

is dependent on the pH of the water. While flufenpyr ethyl could degrade within days in neutral 

water (t ?4 = 8 days) and within hours in alkaline water (t ?4 = 3 hours), it remains quite stable in 

acidic water (t ?h = 300 days). On soils, flufenpyr ethyl quickly biodegrades (t ?h < 2 hours) into S3 153-acid. Three other major metabolites are also subsequently formed, S-3 153-1 -OH, S-3 153-1- 

OCH, and S-3153-1-OCH,-5'-CH20H, along with some minor level of CO,, S-3153-1-OCH,-5'- 

COH, and some bound residues. In a sediment-water system, rapid degradation of flufenpyr ethyl 

(t ?4 < 2 hours) to S-3 153-acid is also noted. S-3 153-acid in turn degrades to S-3 153-1 -OH, which 

seems to be more persistent under anaerobic conditions (t ?4 = 866 days) than under aerobic 

conditions (t ?4 = 108 days). Both S-3 153-acid and S-3 153-1-OH are major metabolites in the 

sediment-water system. Major and minor metabolites of flufenpyr ethyl are listed in Table 5. 

The estimated KO, value from the leaching and Adsorption/Desorption studies indicates that 

flufenpyr ethyl has some leaching potential. However, since other dissipation routes such as 

degradation and mineralization are more important and more rapid, the likelihood of flufenpyr ethyl 

leaching into ground water could be greatly reduced. In contrast, two of its major metabolites, S3 153-acid and S-3 153- 1 -OH, seem to be more mobile and could have greater ability to reach ground 

water than the parent. SCI-GROW model results show that S-3 153-acid could reach ground water 

at a higher level than the parent. Nevertheless, in the field studies, neither flufenpyr ethyl nor these 

degradates were detected below the 3" soil depth at above the study detection limit (2 ppb). 

The environmental fate data, physical-chemical properties, and surface water modeling results 

suggest that drift, if any, may be the most important route of potential exposure for flufenpyr in 

surface water. However, even if it reaches ground water, flufenpyr ethyl is prone to hydrolysis 

(except in acidic aquatic environment) and should not present a major concern to surface water 

resources. Modeling results from FIRST estimate a peak value of less than 0.1 ppb of flufenpyr ethyl 

Proyosed Uses for Flufenpvr ethyl 

Method of 

Appl. 

broadcast 

aerial / 

broadcast 

broadcast 

aerial / 

broadcast 

Max 

Appllyear 

(Ib ailacre) 

0 0323 

0.054 

0 0532 

0.054 

PCA 

value 

0 46 

0 87 

0 41 

Application 

Interval 

(days) 

10 

10 -14 

10 

10 - 14 

No. 

Appl/year 

2 

2 

2 

2 

Product/ 

Formulation 

S-3153 / Atrazine 

WDG 

S-3153 WDG 

S-3153 / Atraz~ne 

WDG 

S-3153 WDG 

PHI 

(days) 

not 

spec~fied 

90 

90 

45 

Application 

Rate 

(Ib ailacre) 

0,019 

0 027 

0355 

0.027 
residue in surface water under the most conservative scenario. As for the degradates, predicted 

surface water concentrations are higher than that of the parent. However, it should be noted that 

there are uncertainties when modeling the degradates, due to an incomplete database. Consequently, 

several assumptions were made, including degradate stability to hydrolysis and photolysis. This may 

be a conservative assumption based on an analysis of their molecular formulae, especially with S3153-acid, where the chemical structure suggests a higher solubility in water and a higher 

susceptibility to hydrolysis. A detailed assessment and characterization of these uncertainties could 

be found in the "Description of Modeling Inputs and Results" paragraph. 

Table 5 - Flufenpyr ethyl Deeradates 1 I 

Degradates Hydrolysis 

pH 7 

I S-3153-acid * I rnax 92% at 

day 30 

rnax 1.4% at 

day 30 

S-3 153-acid-2,4-(OH)2 

TFPYR 

S-3 153-1-OCH3 * 

Photolysis Photolysis 

(water) (soil) 

rnax 41% at 

day 15 I rnax 23% at 

day 7 I rnax 13% at 

day 32 

rnax 11%at + day 20 

Aerobic Soil 

rnax 84% at 

day 1 

rnax 53% at 

day 177 

rnax 14% at 

day 91 

rnax 19% at 

day 365 

rnax 14% at 

day 365 

Anaerobic Terrestrial 

hours 

7 rnax 8% at 

p rnax 15% at 

rnax 18% at 

day 13 

day 185 

rnax 1%at 

day 300 

rnax 11% at --t 
Description of Modeling Inputs and Results: 

Flufenpvr ethvl 

The drinking water estimated concentrations reported in Table 1 were based on the input 

parameters listed in Table 6. Background information on the models and the model outputs are 

attached in Appendix 1 for FIRST, Appendix 2 for SCI-GROW, and Appendix 3 for GENEEC2. 

FIRST accounts for Percent Cropped Area (PCA). The PCA factor is 41% for soybean. No 

PCA was developed for sugarcane and a default value of 87% was used for this crop. The PCA is 

a generic adjustment which represents the maximum percent of any watershed that is planted to the 

crop being modeled and, thus, may potentially be treated with the pesticide in question. PCA factors 

are generated from Geographic Information System (GIs) overlays of cropping area and watershed 

delineations. EFED believes that the default value of 87% is probably high for sugarcane and the 

results reported for that crop could be overestimated. No PCA adjustment is required for GENEEC2 

or for SCI-GROW. 

rable 6. Input Parameters for Drinking 

Application rate 

Parameter 

Solubility (water) 

Hydrolysis t,, (pH 7) 

Aq. Photolysis t,, (pH 

7) 

Aerobic Soil 

Metabolism t,,2 

Aerobic Aquatic 

Metabolism t,,2 

PCA value 

Range 

4.lmgIL 

- - -- 

8.5 days 

2.8,2.9,4.4, and 

4.9 days 

0.0496 days 

no data 

0.027 Ib ai/A, 2 

app, 10-day 

interval 

Y ater Concentrations 

I I 

4.9 days (maximum) (FIRSTIGENNECZ) I MRTD 45 1190-20 1 

Value Used in Model 

4.1 mg/L (FIRSTlGENNEC2) 

8.5 days (FIRSTlGENEEC2) 

Source 

Product 

Chemistry 

MRID451190-19 

0.0271b ai1A 2 appl, 10-day interval 

(FIRSTlGENEEC2lSCI-GROW) 

0.0496 x 3 = 0.15 days (FIRSTlGENEEC2) 

0.0496 days (SCI-GROW) 

0 day (stable). Hydrolysis will be the ratedetermining process (FIRSTlGENEEC2) 

4 15 mL1g (one estimated value) 

(FIRSTlGENEEC2lSCI-GROW) 

Label information 

MRID 45 1 190-22 

MRID 451 191-01 

field corn: 46% (FIRST) I I 

sugarcane: 87% (default) (FIRST) 

soybean: 41% (FIRST) 

Since, only one half life was reported for aerobic soil metabolism, EFED uses three times that 

value to account for the uncertainty associated with a single laboratory study. The maximum 

allowable rate of 0.054 lb ai/A/year and the slowest photolysis rate were also simulated to achieve 

the most conservative surface water contamination scenario. 

EFED Policy 

Flufen~vr ethvl degradates: 
Four major degradates were reported in the fate laboratory studies, S-3 153-acid, S-3 153-1-OH, 

S-3 153-1-OCH3, and S-3 153-1-OCH3-5'-CH20H and were identified as degradates of importance 

to the human health effect assessment by the MARC meeting of June 26,2003. The DWECs were 

estimated for all these degradates, except S-3153-1-OCH3-5'-CH20H for which there are 

insufficient environmental fate data. The input parameters used in the water models are listed below. 

3-3153 Acid 

Parameter Range Value Used in Model 

assume solubility of parent: 

4.1 mg/L (FIRST) 

assume stable - 0 day (FIRST) 

assume stable - 0 day (FIRST) 

38.5 x 3 = 115.5 days (FIRST) 

Solubility (water) 

Source 

Product 

Chemistry 

MRID 451 190-19 

MRID 45 1 190-20 

MRID 45 1 190-22 

no data 

Hydrolysis t,, (pH 7) no data 

Aq. Photolysis t,, (pH 7) no data 

Aerobic Soil Metabolism t,, 38.5 days 

use 2xaerobic soil metabolism t,, 

115.5 x 2 = 231 days (FIRST) 

Aerobic Aquatic 

Metabolism t,, 

no data 

19 mL/g (lowest non sand) 

(FIRSTlGENEEC2) 

19 mL1g (lowest value) (SCI-GROW) 

0.027*0.835*380.7/408.7 = 0.021 1b ai/A 

2 appl, 10-day interval, aerial application, 

no drift (FIRST & SCI-GROW) 

Application rate per label: 

0.027 lb ai/A, 2 app, 10-day 

interval 

max 83.5% of 

applied formedMW = 380.7 

Label information 

PCA value no data default = 87% (FIRST) EFED Policy 

Solubility (water) no data assume solubility of parent: I 4.1 mg/L (FIRST) 

3-3153-1-OH 

Product 

Chemistry 

Parameter Source 

Hydrolysis t,, (pH 7) 

Aq. Photolysis t,, (pH 7) 

Range 

Aerobic Soil Metabolism t,, 

Aerobic Aquatic 

Metabolism t,, 

KO, 

0.027*0.141*336.7/408.7 = 0.003 lb ai/A 

2 appl, 10-day interval, aerial application, 

no drift (FIRST & SCI-GROW) 

default = 87% (FIRST) 

Value Used in Model 

no data 

no data 

Application rate per label: 

0.027 lb ai/A, 2 app, 10-day 

interval 

Label information 

7.1 days 

no data 

149, 159,203, 

and 2 16 mL/g 

max 14.1% of 

applied formedMW = 336.7 

assume stable - 0 day (FIRST) 

assume stable - 0 day (FIRST) 

EFED Policy 

MRID 451 190-19 

MRID 45 1 190-20 

7.1 x 3 = 21.3 days (FIRST) 

use 2xaerobic soil metabolism t,, 

21.3 x2 =42.6 days (FIRST) 

149 mL/g (lowest non sand) 

(FIRSTlGENEEC2) 

149 mL/g (lowest value) (SCI-GROW) 

PCA value for sugarcane 

MRID 45 1 190-22 

MRID 451 191-01 

no data 
Parameter 

Solubility (water) 

Hydrolysis t,, (pH 7) 

Aq. Photolysis t,, (pH 7) 

Aerobic Soil Metabolism t,, 

1 210,226,249, 1 2 10 mL/g (lowest non sand) (FIRST) 

and 284 mL/g 238 mC/g (median value) (SCI-GROW) 

Range 

no data 

no data 

no data 

Aerobic Aquatic 

Metabolism t,, 

47.6 days 

I PCA value for sugarcane I no data I default = 87% (FIRST) I EFED policy I 

Value Used in Model 

assume solubility of parent: 

4.1 mg/L (FIRST) 

assume stable - 0 day (FIRST) 

assume stable - 0 day (FIRST) 

no data 

-- -- 

Application rate per label: 

0.027 lb aiIA, 2 app, 10-day 

interval 

As note above, the DWECs reported for the degradates have high degree of uncertainty and 

should be considered for screening purpose only. Among the assumptions used for estimating the 

DWECs for the degradates are: 

1. Single application rate of each degradate was adjusted from the proposed rate listed in 

Table 4 proportionally to their maximum detected concentration relative to the total 

amount applied and to their molecular weight. 

2. Although aerial application was simulated, no drift was assumed for the degradates as 

they were formed in soils, after application. This assumption gives lower surface water 

values, however non significant, since the application rates are low. 

3. No solubility data exist for the degradates and their solubility was assumed equal to the 

parent's. No major impact on the data is expected, as these Tier 1 screening models are 

not very sensitive to the change in solubility data. 

4. No hydrolysis or photolysis data were received for the degradates. Although their 

chemical formulae indicate higher susceptibility to hydrolysis and photolysis than parent, 

stability was assumed for all of the modeled degradates, according to the current EFED 

policies. This assumption would not impact the peak (acute) surface water 

concentrations, however does result in higher annual average (chronic) values. 

5. Insufficient data were submitted for S-3 153-1-OCH3-5'-CH,OH to estimate its DWECs. 

Although a major degradate in the aerobic soil metabolism study (maximum 13.9% of 

applied), this degradate was only found in the top soil layer of one out of three field studies 

at the analytical method detection limit level. Therefore EFED expects the risk of this 

degradate to the drinking water resources to be negligible compared to that of the parent 

and the other three degradates. 

Despite all these uncertainties, EFED is confident that the reported DWECs provide an upper 

bound estimate of potential contamination of flufenpyr ethyl degradates in surface and ground water. 

Source 

Product 

Chemistry L 

MRID 451 190-19 

MRID 45 1 190-20 

47.6 x 3 = 142.8 days (FIRST) 

use 2xaerobic soil metabolism t,, 

142.8 x 2 = 285.6 days (FIRST) 

MRID 45 1 190-22 

max 53.2% of 

applied formedMW = 350.7 

0.027*0.532*350.7/408.7 = 0.012 lb ai/A 

2 appl, 10-day interval, aerial application, 

no drift (FIRST & SCI-GROW) 

Label information 
Appendix 1. FIRST ( FQPA Index Reservoir Screening xool) Model. 

Background In formation on FIRST: 

FIRST is a screening tool designed to estimate the pesticide concentrations found in surface 

water for use in drinking water assessments. It provides high-end values of the concentrations that 

might be found in a small drinking water reservoir due to the use of pesticide. FIRST is a singleevent model (one run-off event), but can account for spray drift from multiple applications. The 

FIRST scenario includes a 427-acre field immediately adjacent to a 130-acre reservoir, 9 feet deep, 

with continuous flow (two turnovers per year). The reservoir receives off-target spray drift event 

from each application plus one runoff event. The runoff event moves a maximum of 8% of the 

applied pesticide into the reservoir. This amount can be reduced due to degradation on the field and 

the effect of binding to soil. Spray drift is equal to 6.4% of the applied concentration &om ground 

spray application and 16% for aerial applications. 

FIRST also makes adjustments for the percent cropped area (PCA). While FIRST assumes 

that the entire watershed would not be treated, the use of a PCA default value of 0.87, is still a screen 

because it represents the highest percentage of crop cover of any large watershed in the United 

States, and it assumes that the entire crop is being treated. Various other conservative assumptions 

of FIRST include the use of a small drinking water reservoir surrounded by a runoff-prone 

watershed, the use of the maximum use rate, no buffer zone, and a single large rainfall. 

First Output for Flufenpyr ethyl on Sugarcane - * INPUT VALUES * 

RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE %CROPPED INCORP 

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN) 

FIELD AND RESERVOIR HALFLIFE VALUES (DAYS) .................................................................................................................................... 

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

(FIELD) RAINIRUNOFF (RESERVOIR) (RES.-EFF) (RESER.) (RESER.) 

UNTREATED WATER CONC (NANOGRAMSLITER (PPTr)) Ver 1.0 AUG 1,200 I 

PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC) 

CONCENTRATION CONCENTRATION 
First Output for Flufenpyr ethyl on Soybean - * INPUT VALUES * .................................................................................................................................... 

RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE %CROPPED INCORP 

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN) .................................................................................................................................... 

.027( .027) 2 10 415.0 4.1 AERIAL(16.0) 41.0 .O 

FIELD AND RESERVOIR HALFLIFE VALUES (DAYS) 

METABOLIC DAYSUNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

(FIELD) RAIN/RUNOFF (RESERVOIR) (RES.-EFF) (RESER.) (RESER.) 

UNTREATED WATER CONC (NANOGRAMSLITER (PPTr)) Ver 1.0 AUG 1,200 1 

PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC) 

CONCENTRATION CONCENTRATION 

First Output for Flufenpyr ethyl on Field Corn - * INPUT VALUES * 

RATE (WAC) No.APPS & SOIL SOLUBIL APPL TYPE %CROPPED INCORP 

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN) 

FIELD AND RESERVOIR HALFLIFE VALUES (DAYS) .................................................................................................................................... 

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

(FIELD) RAINRUNOFF (RESERVOIR) (RES.-EFF) (RESER.) (RESER.) 

.15 2 8.50 4.90- 607.60 .OO 8.38 

UNTREATED WATER CONC (NANOGRAMSLITER (PPTr)) Ver 1.0 AUG 1,200 1 

PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC) 

CONCENTRATION CONCENTRATION 
First Output for S-3153-Acid on Sugarcane -* INPUT VALUES * 

RATE (#lAC) No.APPS & SOIL SOLUBIL APPL TYPE %CROPPED INCORP 

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN) 

.021( .041) 2 10 19.0 4.1 AERIAL( .O) 87.0 .O 

FIELD AND RESERVOIR HALFLIFE VALUES (DAYS) 

METABOLIC DAYSUNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

(FIELD) MINIRUNOFF (RESERVOIR) (RES.-EFF) (RESER.) (RESER.) 

115.50 2 NIA .OO- .OO 23 1 .OO 23 1 .OO 

UNTREATED WATER CONC (MICROGRAMSILITER (PPB)) Ver 1.0 AUG 1,200 1 

PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC) 

CONCENTRATION CONCENTRATION 

First Output for S-3153-1-OH on Sugarcane - * INPUT VALUES * .................................................................................................................................... 

RATE (WAC) No.APPS & SOIL SOLUBIL APPL TYPE %CROPPED INCORP 

ONE(MULT) INTERVAL Koc (PPM (%DRIFT) AREA (IN) 

FIELD AND RESERVOIR HALFLIFE VALUES (DAYS) .................................................................................................................................... 

METABOLIC DAYSUNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

(FIELD) RAINIRUNOFF (RESERVOIR) (RES.-EFF) (RESER.) (RESER.) .................................................................................................................................... 

21.30 2 NIA .OO- .OO 42.60 42.60 

UNTREATED WATER CONC (NANOGRAMSILITER (PPTr)) Ver 1.0 AUG 1,2001 ..................................................................................... 

PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC) 

CONCENTRATION CONCENTRATION 
First Output for S-3153--1-OCH, on Sugarcane - * INPUT VALUES * 

RATE (WAC) No.APPS & SOIL SOLUBIL APPL TYPE %CROPPED INCORP 

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN) .................................................................................................................................... 

.012( .023) 2 10 210.0 4.1 AERIAL( .O) 87.0 .O 

FIELD AND RESERVOIR HALFLIFE VALUES (DAYS) 

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

(FIELD) RAINIRUNOFF (RESERVOIR) (RES.-EFF) (RESER.) (RESER.) 

UNTREATED WATER CONC (MICROGRAMSILITER (PPB)) Ver 1.0 AUG 1,2001 

PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC) 

CONCENTRATION CONCENTRATION 
Appendix 2. SCI-GROW ( Screening Concentration in Ground~ater) Model. 

Background Information on SCI-GRO W: 

SCI-GROW is a regression-based, Tier 1 screening model that provides a groundwater 

screening exposure value to be used in determining the potential risk to human health from drinking 

water contaminated with pesticide. Since the SCI-GROW concentrations are likely to be approached 

in only a very small percentage of drinking water sources, i.e., highly vulnerable aquifers, it is not 

appropriate to use SCI-GROW for national or regional exposure estimates. 

SCI-GROW estimates likely groundwater concentrations if the pesticide is used at the 

maximum allowable rate in areas where groundwater is exceptionally vulnerable to contamination. 

In most cases, a large majority of the use area will have groundwater that is less vulnerable to 

contamination than the areas used to derive the SCI-GROW estimate. 

SCI-GROW Output forfIrcfenpyr ethyl ** INPUT VALUES ** .............................................................................................................................. 

APP RATE APPSI TOTAL1 SOIL AEROBIC SOIL METAB 

(LB SIAC) YEAR SEASON KOC HALFLIFE (DAYS) .............................................................................................................................. 

.027 2 .054 415.0 .05 

GROUND-WATER SCREENING CONCENTRATION (IN UGL - PPB) ........................................................ 

.000000 ** See Note Below ** VERSION 2.2: NOVEMBER 1,200 1 -----------*-------------------------------------------- 

** Values below 0.006 ppb (6 ng/L) are beyond the scope of the regression data in SCI-GROW 2.2 and have not 

been verified. If concerns are raised by exposures of less than 0.006 ppb, a higher-tier ground-water exposure 

assessment should be considered, regardless of how low a screening concentration is returned by SCI-GROW. 

SCI-GRO W Output for S-3153-Acid * * INPUT VALUES * * ................................................................................................................................ 

APP RATE APPSI TOTAL1 SOIL AEROBIC SOIL METAB 

(LBSIAC) YEAR SEASON KOC HALFLIFE (DAYS) ................................................................................................................................ 

.021 2 .042 19.0 38.50 

GROUND-WATER SCREENING CONCENTRATION (IN UGL - PPB) ........................................................ 

,03593 1 VERSION 2.2: NOVEMBER 1,200 1 ........................................................ 
SCI-GRO W Output for S-3153-1-OH ** INPUT VALUES ** 

APP RATE APPSI TOTAL1 SOIL AEROBIC SOIL METAB 

(LBSIAC) YEAR SEASON KOC HALFLIFE (DAYS) 

GROUND-WATER SCREENING CONCENTRATION (IN UG/L - PPB) 

.000078 ** See Note Below ** VERSION 2.2: NOVEMBER 1,2001 ........................................................ 

** Values below 0.006 ppb (6 ng/L) are beyond the scope of the regression data in SCI-GROW 2.2 and have not 

been verified. If concerns are raised by exposures of less than 0.006 ppb, a higher-tier ground-water exposure 

assessment should be considered, regardless of how low a screening concentration is returned by SCI-GROW. 

SCI-GROW Output for S-3153-1-OCH, ** INPUT VALUES ** 

APP RATE APPSI TOTAL1 SOIL AEROBIC SOIL METAB 

(LB SIAC) YEAR SEASON KOC HALFLIFE (DAYS) 

GROUND-WATER SCREENING CONCENTRATION (IN UGIL - PPB) ........................................................ 

.005505 ** See Note Below ** VERSION 2.2: NOVEMBER 1,200 1 ........................................................ 

** Values below 0.006 ppb (6 ngL) are beyond the scope of the regression data in SCI-GROW 2.2 and have not 

been verified. If concerns are raised by exposures of less than 0.006 ppb, a higher-tier ground-water exposure 

assessment should be considered, regardless of how low a screening concentration is returned by SCI-GROW. 
Appendix 3. GENEECZ ( GENeric Estimated Environmental Concentration) Model. 

Background Information on GENEEC: 

The GENEEC2 (GENeric Estimated Environmental Concentration) model, the tier one computer 

program, uses the soillwater partition coefficient and degradation kinetic data to estimate runoff from 

a ten hectare field into a one hectare by two meter deep "standard" pond. This first tier is designed 

as a coarse screen and estimates conservative pesticide concentrations in surface water from a few 

basic chemical parameters and pesticide label use and application information. Tier 1 is used to 

screen chemicals to determine which ones potentially pose sufficient risk to warrant higher level 

modeling. 

GENEEC2 Output forflufenpyr ethyl on sugarcane with ground application - * INPUT VALUES * 

RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

(FIELD) RAINIRUNOFF (POND) (POND-EFF) (POND) (POND) 

GENERIC EECs (IN NANOGRAMSLITER (PPTr)) Version 2.0 Aug 1,2001 ............................................................................................................... 

PEAK MAX4DAY MAX21DAY MAX60DAY MAX90DAY 

GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC ................................................................................................................ 

142.04 137.28 96.94 51.19 35.82 

GENEEC2 Output forflufenpyr ethyl on sugarcane with aerial application - * INPUT VALUES * 

RATE (MAC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) 

.027( .027) 2 10 415.0 4.1 AERL-B(13.6) .O .O 

FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

(FIELD) RAINRUNOFF (POND) (POND-EFF) (POND) (POND) 

GENERIC EECs (IN NANOGRAMSLITER (PPTr)) Version 2.0 Aug 1,2001 ---------------------------------------------------------------------*----------------------------------------- 

PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 
GENEEC2 Output for S-3153-acid on sugarcane * INPUT VALUES * .................................................................................................................................... 

RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

ONE(MSJLT) INTERVAL Koc (PPM) (%DRIFT) (FT) (IN) .................................................................................................................................... 

.021( .041) 2 10 19.0 4.1 AERIAL( .O) .O .O 

FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

(FIELD) RAINIRUNOFF (POND) (POND-EFF) (POND) (POND) 

GENERIC EECs (IN MICROGRAMSLITER (PPB)) Version 2.0 Aug 1,2001 ............................................................................................................... 

PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC ................................................................................................................ 

2.19 2.19 2.15 2.08 2.03 

GENEEC2 Output for S-3153-1-OH on sugarcane * INPUT VALUES * 

RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

ONE(WLT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) .......................................................................................................................................... 

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

(FIELD) RAINRUNOFF (POND) (POND-EFF) (POND) (POND) 

21.30 2 NIA .OO- .OO 42.60 42.60 

GENERIC EECs (IN NANOGRAMSILITER (PPTr)) Version 2.0 Aug 1,200 1 

PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC --------------------------------------------------------------------------------------------------------*------- 

215.47 212.39 196.05 164.58 145.01 
Appendix IV - Ecological Effects Toxicity Studies 

Toxicity to Terrestrial Animals 

I. Birds, Acute and Subacute dietary 

One acute oral toxicity study using the technical grade of the active ingredient (TGAI) is required 

to establish the toxicity of flufenpyr-ethyl to birds. The preferred test species are the mallard duck 

(Anasplatyrhynchos) and/or bobwhite quail (Colinus virginianus). Since the LD50 is greater than 

2000 mg/kg (Table I), flufenpyr-ethyl is categorized as practically nontoxic to avian species on an 

acute exposure basis. The guideline (71-1) is fulfilled (MRID 45 1 188 15). 

Table 1. Acute Toxicitv of Flufen~vr-ethvl to Northern bobwhite. 

Avian Acute Oral Toxicity 

Species % ai Toxicity value Toxicity category MRID no. Study classification 

Northern bobwhite quail 97 LD50 22250' mglkg practically nontoxic 45118815 core1 

(Colinus virginianus) 

' Core (study satisfies guideline). Supplemental (study is scientifically sound, but does not satisfy guideline) 

no mortality reported 

Two subacute dietary toxicity studies using the TGAI are required to establish the toxicity of 

flufenpyr-ethyl to birds. The preferred test species are the mallard duck (Anas platyrhynchos) and 

bobwhite quail (Colinus virginianus). Since the LC5Os are greater than 5000 ppm (Table 2), 

flufenpyr-ethyl is categorized as practically nontoxic to avian species on a subacute exposure basis. 

The guideline (71-2a,b) is fulfilled (MRID 451 18816 and 451 18817). 

Table 2. Subacute Dietary Toxicity of Flufenpyr-ethyl to Northern bobwhite and Mallard ducks. 

Avian Subacute Dietary Toxicity 

Species % ai Toxicity value Toxicity category MRID no. Study Classification 

Northern bobwhite quail 97 LC50 >56201 ppm practically nontoxic 45118817 core 

(Colinus virginianus) 

Mallard duck LC50 >56201 ppm practically nontoxic 45118816 core 

(Anasplatyrhynchos) 

' no mortality reported 

11. Birds, Reproductive 

Avian reproduction studies using the TGAI are required for flufenpyr-ethyl because multiple 

applications may subject birds to repeated or continuous exposure during or preceding the breeding 

season. The preferred test species are the mallard duck and northern bobwhite. Results indicate an 

NOAEC of 164 ppm and an LOAEC of 424 ppm, based on the 14D survivorlnormal hatchling and 

final weight of mallard ducks (Table 3). The guideline (7 1-4) is fulfilled (MRID 45 1 188 18, -1 9). 
Table 3. Chronic Toxicity of Flufenpyr-ethyl to Bobwhite quail and Mallard ducks. 

Avian Reproduction 

Species % ai NOAEC (ppm) LOAEC Affected endpoints MRID no. Study classification 

Northern bobwhite 97 1040 > 1040 none 451188-19 core ' 

Mallard 97 164 424 14D survivor/normal 451188-18 core ' 

hatchling and female 

body weight 

' Core (study satisfies guideline). Supplemental (study is scientifically sound, but does not satisfy guideline). Invalid (study is scientifically unsound 

and does not satisfy guideline). 

111. Mammals, Acute and Reproductive 

Wild mammal testing is required on a case-by-case basis, depending on the results of lower tier 

laboratory mammalian studies, intended use pattern and pertinent environmental fate characteristics. 

In most cases, rat or mouse toxicity values obtained from the Agency's Health Effects Division 

(HED) substitute for wild mammal testing. Since the LD50 value exceeded 5,000 mgkg (Table 4), 

flufenpyr-ethyl is categorized as practically non-toxic to small mammals on an acute oral basis. 

Results from the 2-generation reproduction study indicate an NOAEC of 1463 ppm (Table 5) to 

small mammals on a chronic exposure basis. 

Table 4. Acute Toxicity of Flufenpyr-ethyl to Mammals. 

Mammalian Acute Oral Toxicity 

Species % ai Test type Toxicity value MRU> no. 

Laboratory rat 57 6 acute oral LD50 r5000 m&g 45118902 

Table 5. Chronic Toxicity of Flufenpyr-ethyl to Mammals. 

Mammalian Reproduction 

Species % ai Test type Toxicitv value MRID no. 

Laboratory rat 57.6 2-generation NOAEC= 1463 ppm 45 1 190-01 & -02 

reproduction LOAEC =Not Identified 

IV. Beneficial Insects 

A honey bee (Apis mellfera) acute contact study using the TGAI is required for flufenpyr-ethyl, 

because its use may result in honey bee exposure. Since the LD50 is greater than 25 ughee (Table 

6), flufenpyr-ethyl is practically non-toxic to bees on an acute contact basis. The guideline (141-1) 

is fulfilled (MRID No. 45 1 190 18). 
Table 6. Acute Contact Toxicity of Flufenpyr-ethyl to Honeybees. 

Nontarget Insect Acute Contact Toxicity 

Species % ai LD50 Toxicity category MRID no. Study classification 

Honey bee tech >25 pglbee' practically nontoxic 45119018 core 

I 33% mortality in some treatment levels were reported 

Toxicity to Freshwater Aquatic Organisms 

V. Freshwater Fish, Acute 

Two freshwater fish toxicity studies using the TGAI are required to establish the toxicity of 

flufenpyr-ethyl to fish. The preferred test species are rainbow trout (a coldwater fish) and bluegill 

sunfish (a warmwater fish). Since the LC5Os fall within the range between 1 - 10 mg/L (Table 7), 

flufenpyr-ethyl is categorized as moderately toxic to freshwater fish on an acute exposure basis. The 

guideline (72-1) is fulfilled (MRID 45 1 188-21 and 45 1 188-20). 

Table 7. Acute Toxicity of Flufenpyr-ethyl to Freshwater Fish. 

Freshwater Fish Acute Toxicity 

Species % ai LC50 Toxicity category MRID no. Study classification 

Rainbow trout 96.8 3.75 mg/L moderately toxic 451188-21 core 

Bluegill sunfish 97 2.537 mg/L moderately toxic 451 188-20 core 

VI. Freshwater Fish, Chronic 

A freshwater fish early life-stage test using the TGAI is required for flufenpyr-ethyl because the enduse product may be applied directly to water or could be transported to water from the intended use 

site, and the following conditions are met: (1) the pesticide is intended for use such that its presence 

in water is likely to be continuous or recurrent regardless of toxicity, (2) any aquatic acute LC50 or 

EC50 is less than 1 mg/L, (3) the EEC in water is equal to or greater than 0.01 of any acute LC50 

or EC50 value, or, (4) the actual or estimated environmental concentration in water resulting from 

use is less than 0.0 1 of any acute LC50 or EC50 value and any one of the following conditions exist: 

studies of other organisms indicate the reproductive physiology of fish may be affected, 

physicochemical properties indicate cumulative effects, or the pesticide is persistent in water (i. e., 

half-life greater than 4 days). The preferred test species is rainbow trout. Results from the early lifestage study indicate adverse growth effects at 0.44 - 0.92 mg/L (Table 8) on a chronic exposure 

basis. The guideline (72-4) is fulfilled. (MRID 451 188-27). 
Table 8. Chronic Toxicity of Flufenpyr-ethyl to Freshwater Fish. 

Freshwater Fish Early Life-Stage Toxicity Under Flow-through Conditions. 

Species % ai NOAEC LOAEC Affected Endpoints MRID No. Study Classification 

Rainbow trout 96.8 0.44 mg/L 0.92 mg/L growth 451 188-27 supplemental' 

test concentrations were below detectable limits for approximately 20 hours on Day 22-23. 

VII. Freshwater Invertebrate, Acute 

A freshwater aquatic invertebrate toxicity test using the TGAI is required to establish the toxicity 

of flufenpyr-ethyl to aquatic invertebrates. The preferred test species is Daphnia magna. Since the 

EC50 is >3 m@ (Table 9), the value is greater than the maximum water solubility of flufenpyrethyl. Thus, the toxicity of flufenpyr-ethyl to freshwater invertebrates could not be characterized on 

an acute exposure basis. The guideline (72-2) is fulfilled (MRID 45 1 188-23). 

Table 9. Acute Toxicity of Flufenpyr-ethyl to Freshwater Invertebrates. 

Freshwater Invertebrate Acute Toxicity Under Flow-through Conditions 

Species % ai EC50 Toxicity category MRID No. Study Classification 

Water flea 96.8 >3 mg!L nla 45 1 18823 supplemental' 

' environmental test conditions were higher than the guideline recommendations. 

VIII. Freshwater Invertebrates, Chronic 

A freshwater aquatic invertebrate life-cycle test using the TGAI is required because flufenpyr-ethyl 

could be transported to water from the intended use sites. The preferred test species is Daphnia 

magna. Results from the life cycle study indicate adverse reproduction effects at 0.46 - 1.2 mg/L 

(Table 10). The guideline (72-4) is fulfilled (MRID 45 11 88-26). 

Table 10. Chronic Toxicity of Flufenpyr-ethyl to Freshwater Invertebrates. 

Freshwater Invertebrate Life-Cycle Toxicity Under Flow-through Conditions 

Species %ai NOAEC LOAEC Affected endpoints MRID no. Study classification 

Water flea 96.8 0.46 mg/L 1.2 mg/L reproduction 45 1 18826 core 

Toxicity to EstuarineNarine Aquatic Organisms 

IX. EstuarineMarine Fish, Acute 

Acute toxicity testing with estuarinelmarine fish is required for flufenpyr-ethyl since the end-use 

product may be applied directly to water, could be transported to water from the intended use site 

or the herbicide is persistent in water (i.e., half-life greater than 4 days) and may contaminate the 

estuarinelmarine environment. The preferred test species are the sheepshead minnow (Cyprinodon 
variegatus) or the Silverside (Menidia sp.). Since the ~650 value is greater than 2.7 mg/L (Table 

ll), the value is greater than the maximum water solubility of flufenpyr-ethyl. Thus, the toxicity of 

flufenpyr-ethyl to estuarinelrnarine fish could not be characterized on an acute exposure basis. The 

guideline (72-3a) is fulfilled (MRID 451 188-22). 

Table 11. Acute Toxicity of Flufenpyr-ethyl to EstuarineIMarine Fish 

EstuarineMarine Fish Acute Toxicity Under Flow-through Condition 

Species % ai LC50 Toxicity category MRID no. Study classification 

Sheepshead minnow 97 >2.7 mgiL n/a 451 188-22 core 

X. EstuarineIMarine Invertebrates, Acute 

Acute toxicity testing with estuarinelmarine invertebrates is required for since the end-use product 

may be applied directly to water or could be transported to water from the intended use site or the 

herbicide is persistent in water (i.e., half-life greater than 4 days) and may contaminate the 

estuarinelmarine environment. The preferred test species are the mysid shrimp (Mysidopsis bahia) 

and Eastern oyster (Crassostrea virginica). Since the EC5Os fall within the range of 1 - 10 mgL 

(Table 12), flufenpyr-ethyl is categorized as moderately toxic to estuarinelmarine invertebrates on 

an acute exposure basis. The guideline (72-3b and c) are fulfilled (MRID 451 188-24 and 45 11 88- 

25). 

Table 12. Acute Toxicity of Flufenpyr-ethyl to EstuarineIMarine Invertebrates 

EstuarineMarine Invertebrate Acute Toxicity Under Flow-through Conditions 

Species % ai EC50 Toxicity category MRID no. Study Classification 

Mysid shrimp 97 2.08 mgiL moderately toxic 45 1188-25 core 

Eastern oyster (shell deposition) 97 >2 mg/L nla 45 11 88-24 core 

XI. EstuarineIMarine Fish and Invertebrates, Chronic 

Estuarinelmarine chronic testing using the TGAI is not required because chronic exposure to 

flufenpyr-ethyl is not expected. 

Toxicity to Terrestrial and Aquatic Plants 

XII. Terrestrial Plants 

Terrestrial plant testing (seedling emergence and vegetative vigor) is a standard requirement only 

for herbicides that have terrestrial non-residential outdoor use patterns and that may move off the 

application site through drift (aerial) andlor that may have endangered or threatened plant species 

associated with the application site. For seedling emergence and vegetative vigor testing the 
following plant species and groups should be tested: (1) six species of at least four dicotyledonous 

families, one species of which is soybean (Glycine max) and the second is a root crop, and (2) four 

species of at least two monocotyledonous families, one of which is corn (Zea mays). 

Normally, tier I testing with the herbicide is conducted at the highest use rate on the label. Then, Tier 

I1 testing is required if any species in tier I is inhibited 25% or more. In this case, the registrant 

conceded a 25% inhibition and proceeded directly to tier I1 seedling emergence and vegetative vigor 

studies instead of tier I studies. 

Based on an application rate of 0.029 lb ai/A, lettuce (0.012 lb/A) is the most sensitive dicot while 

onion (0.018 lb/A) is the most sensitive monocot (Table 13) in the seedling emergence tier I1 

toxicity test. The guideline (123-la) is fulfilled (MRID 45 1 190-1 6) for the seedling emergence test. 

The tier I1 seedling emergence toxicity test measures the response of plants, relative to a control, and 

five or more test concentrations of a pesticide. This simulates the response of non-target plants 

subjected to runoff from adjacent treated areas. Results of tier I1 toxicity testing on the TEP material 

are tabulated below. 

Table 13. Toxicity of Flufenpyr-ethyl To Terrestrial Plants using Tier I1 Seedling Emergence. 

Nontarget Terrestrial Plant Seedling Emergence Toxicity (Tier 11) 

Species % ai EC25 (Ibs ai/A) NOAEC Endpoint Affected1 MRID No. Study Classification 

50.0 451190-16 

Monocot- Corn >0.029 0.029 none core 

Monocot- Oat >0.029 0.029 none core 

Monocot- Onion 0.018 0.0097 weight core 

Monocot- Ryegrass >0.029 0.029 none core 

Dicot-Soybean >0.029 0.029 none core 

Dicot- Lettuce 

Dicot- Radish 

Dicot-Cucumber 

Dicot- Cabbage 

0.012 0.0097 weight 

0.016 0.0032 weight 

>0.029 0.029 none 

0.016 0.0097 weight 

core 

core 

core 

core 

Dicot- Tomato >0.029 0.029 none core 

' only the most sensitive endpoint is tabulated 

Tier I1 vegetative vigor studies indicate that at an application rate of 0.029 lb ai/A, tomato (0.00009 

1bIA) is the most sensitive dicot while onion (0.0056 lb/A) is the most sensitive monocot (Table 14). 

The guideline (1 23- 1 b) is fulfilled (MRID 45 1 190- 17) for the vegetative vigor test. 

The vegetative vigor toxicity test measures the response of plants, relative to a control, and five or 

more test concentrations that simulate the effects of drift to non-target plants in adjacent areas. 

Results of Tier I1 toxicity testing on the TEP material are tabulated below. 
Table 14. Toxicity of Flufenpyr-ethyl To Terrestrial Plants using Tier I1 Vegetative Vigor. 

Nontarget Terrestrial Plant Vegetative Vigor Toxicity (Tier 11) 

Species % ai EC25 (Ibs ai/A) NOAEC Endpoint Affected1 MRID No. Study Classification 

Monocot- Corn 

Monocot- Oat 

Monocot- Onion 

Monocot- Ryegrass 

Dicot-Soybean 

Dicot- Lettuce 

Dicot- Radish 

Dicot-Cucumber 

Dicot- Cabbage 

none 

none 

height 

none 

none 

weight 

weight 

weight 

weight 

core 

core 

core 

core 

core 

core 

core 

core 

core 

Dicot- Tomato 0.00009 0.00004 weight core 

'only the most sensitive endpoint is tabulated 

XIV. Toxicity to Aquatic Plants 

Aquatic plant testing is required for any herbicide that has outdoor non-residential terrestrial uses 

and that may move off-site by runoff (solubility >10 ppm in water), and/or by drift (aerial) or that 

is applied directly to aquatic use sites (except residential). Normally, tier I testing with the TGAI 

is conducted on duckweed (Lemna gibba), a vascular species, and a green algae (Skeletonema 

costatum), a nonvascular species. Then, tier I1 testing is required if either species in Tier I is inhibited 

50% or more, and also includes Selenastrum capricornutum, Anabaenaflos-aquae, and a freshwater 

diatom. In this case, the registrant chose to conduct Tier I1 testing even though it may not have been 

triggered. Results of Tier I1 toxicity testing with the vascular aquatic plant, duckweed, and the most 

sensitive non-vascular aquatic plant, the EC5Os were 0.0 12 and 0.009 mg/L respectively (Table 15). 

The guideline (1 23 -2) is fulfilled with all five species tested (MRID 45 1 1 90- 1 1, - 12, - 1 3, - 14, - 1 5). 

Table 15. Toxicity of Flufenpyr-ethyl to Aquatic Plants using Tier 11. 

Nontarget Aquatic Plant Toxicity (Tier 11) 

Species % ai EC50 NOAEC MRID no. Study classification 

Vascular species: 

Duckweed 99.1 0.013 mg/L1 0 003 m&' 451190-11 core 

Nonvascular species: 

AnabaenaJlos-aquae 99.1 >0.5 mg/L1 0.031 rng/L1 451 190-14 core 

Skeletonema costatum 97 0.012 mg/L 0.00081 mg/L 451 190-12 core 

Selenastrum capricornutum 99.1 0.009 mg/L1 <0.0063 rng/L1.' 451 190-15 core 

Navicula pelliculosa 97 0.16 mg/L 0.032 mg/L 451190-13 core 

' nominal concentration 
the NOAEC is below the lowest tested concentration 

Additional duckweed toxicity studies were also submitted by the registrant on flufenpyr-ethyl's 

degradates, S-3 153-acid and S-3 153-4-OH. Results of Tier I1 toxicity testing indicate the EC5Os 

were 0.0063 and B0.03 mg ae/L, respectively (Table 16) The studies were determined to be core 

(MRID 452423-03, -04). 

Table 16. Toxicity of Degradates to Duckweed. 

Nontarget Aquatic Plant Toxicity (Tier 11) 

Species % ai Degradation EC50 (mg a.e./L) NOAEC MRID no. Study classification 

Identification 

Duckweed 98.7 S-3153 acid 0.0063 0.003 452423-04 core 

Duckweed 97.5 S-3 153-4-OH >0.03 0.03 452423-03 core 
Appendix V: Ecological Risk Assessment of Flufenpyr-ethyl 

A means of integrating the results of exposure and ecotoxicity data is called the quotient method. For 

this method, risk quotients (RQs) are calculated by dividing exposure estimates by ecotoxicity 

values, both acute and chronic. 

RQs are then compared to OPP's levels of concern (LOCs). These LOCs are criteria used by OPP 

to indicate potential risk to nontarget organisms and the need to consider regulatory action. The 

criteria indicate that a pesticide used as directed has the potential to cause adverse effects on 

nontarget organisms. LOCs currently address the following risk presumption categories: (1) acute - 

potential for acute risk is high, regulatory action may be warranted in addition to restricted use 

classification, (2) acute restricted use - the potential for acute risk is high, but this may be mitigated 

through restricted use classification, (3) acute endangered species - the potential for acute risk to 

endangered species is high, regulatory action may be warranted, and (4) chronic risk - the potential 

for chronic risk is high, regulatory action may be warranted. Currently, EFED does not perform 

assessment for chronic risk to plants, acute or chronic risks to nontarget insects, or chronic risk from 

granularhait formulations to mammalian or avian species. 

The ecotoxicity test values (i. e., measurement endpoints) used in the acute and chronic risk quotients 

are derived from the results of required studies. Example of ecotoxicity values derived from the 

results of short-term laboratory studies that assess acute effects are: (1) LC,, (fish and birds), (2) 

LD50 (birds and mammals), (3) EC50 (aquatic plants and aquatic invertebrates), and (4) EC25 

(terrestrial plants). Examples of toxicity test effect levels derived from the results of long-term 

laboratory studies that assess chronic effects are: (1) LOAEC (birds, fish, and aquatic invertebrates) 

and (2) NOAEC (birds, fish and aquatic invertebrates). For birds, mammals, and all aquatic 

organisms, the NOAEC is the ecotoxicity test value used in assessing chronic risk. Other values may 

be used when justified. Risk presumptions, along with the corresponding RQs and LOCs are 

summarized in Tables 1 through 3. 

Table 1. Risk presumptions for terrestrial animals (birds and wild mammals) 

Risk Presumption RQ LOC 

Acute Risk EEC1/LC,, or LD,,/ft2 or LD,dday3 0.5 

Acute Restricted Use EEC/LC,, or LD,dftZ or LD,,/day (or LD,, < 50 mgikg) 0.2 

, Acute Endangered Species EECILC,, or LD,dft2 or LD,,/day 0.1 

Chronic Risk EEC/NOAEC 1 ' abbreviation for Estimated Environmental Concentration (ppm) on avian/mammalian food items 

mg/P me of toxicant consumed/day 

LD,, * wt. of bird LD,, * wt. of bird 
Table 2. Risk presumptions for aquatic animals 

Risk Presumption RQ LOC 

Acute Risk EEC1/LC5, or EC,, 0.5 

Acute Restricted Use EECILC,, or EC,, 0.1 

Acute Endangered Species EECILC,, or EC,, 0.05 

Chronic Risk EECINOAEC 1 

' EEC = (ppm or ppb) in water 

Table 3. Risk presumptions for plants 

Risk Presumption RQ LOC 

Terrestrial and Semi-Aquatic Plants 

Acute Risk EEC1/EC2, 1 

Acute Endangered Species EECEC,, or NOAEC 1 

Aquatic Plants 

Acute Risk EEC2/EC5, 1 

Acute Endangered Species EECEC,, or NOAEC 1 

I EEC = lbs ai/A 

EEC = (ppb or ppm) in water 

Exposure and Risk to Nontarget Terrestrial Animals 

For pesticides applied as a nongranular product (e.g., liquid and dust), the estimated environmental 

concentrations (EECs) on food items following product application are compared to LC,, values to 

assess risk. The ELL-FATE model predicted 0-day maximum residues of a pesticide that may be 

expected to occur on selected avian or mammalian food items immediately following two 

applications at 0.027 lb ailA of flufenpyr-ethyl at 10-day intervals is presented in Table 4. 

Table 4. Estimated environmental concentrations on avian and mammalian food items (ppm) following 2 applications at 0.027 

Ib ai/A. -- - 

Application Rate Food Items EEC (PP~) 

Predicted Maximum Residue1 

0.027 Ib a.i./A Short grass 

Tall grass 

Broadleavforage plants and small insects 

Fruits, pods, seeds, and large insects 0.74 

I ELL-FATE predicted maximum residues and adjusted based on Hoerger and Kenaga (1972) as modified by Fletcher et al. (1994). 

Predicted residues (EECs) resulting fiom 2 applications are calculated using the first order linear 

regression model. Uncertainties in the terrestrial EECs are primarily associated with a lack of data 

on interception and subsequent dissipation fiom foliar surfaces. EFED assumes the foliar dissipation 

rate is based on a number of routes which include photolysis, hydrolysis and volatilization. It could 

also include uptake in plants as well as wash off if those data were available. When data are absent, 

as in this case, EFED assumes a 35-day foliar dissipation half life for chemicals that are not volatile 
and which are stable to photolysis and hydrolysis. This 35-day half-life assumption is based on the 

work of Willis and McDowell(1987). 

I. Birds 

Acute 

Since flufenpyr-ethyl is classified as practically nontoxic to birds (LD,, >2150 mg/kg, LC,, >5620 

pprn). Acute risks to bird are presumed to be negligible (Table 5) from any of the proposed new uses 

(soybean, sugarcane, and field corn). The acute risk quotients for single broadcast applications of 

non-granular products are tabulated below. 

Table 5. Avian Acute Risk Quotients for Two Application of Nongranular (broadcast) based on a Bobwhite quail LC,, of 

25000 ppm. 

SiteIApp. Method App FOO~ ltems Maximum Toxicity Value Acute RQ 

(Ibs ai/A EEC (ppm) LC,, (ppm) (EECLC,,) 

0.027 Short grass 11.80 >5000 n/a 

sugarcane (aerial) Tall grass 5.41 >5000 n/a 

Broadleaf 6.64 

plants / Insects >5000 

" exceeds acute high, acute restricted and acute endangered species LOCs. 

exceeds acute restricted and acute endangered species LOCs. 

exceeds acute endangered species LOCs 

exceeds chronic LOC 

nla - when information is not available or when a greater than toxicity value which minimal risk (RQ <0.01) is presumed for the species. 

No acute LOCs are exceeded, even assuming no degradation between applications, the maximum 

EEC on short grass would not be expected to exceed 1 1.8 pprn from 2 applications of 0.027 lb ai/A 

at 10-day intervals for birds. 

Chronic 

Chronic risks were evaluated using maximum estimated environmental concentrations based on a 

Mallard duck NOAEC of 164 pprn (Table 6). Even assuming no degradation between applications, 

chronic risk to bird is believed to be negligible. The chronic risk quotient for a broadcast application 

of non-granular products are tabulated below. 

Table 6. Avian Chronic Risk Quotients for Two Application (maximum residue) of Flufenpyr-ethyl (broadcast) 

based on a Mallard duck NOAEC of 164 ppm. 

SiteIApp. App. Rate Maximum Food Items Toxicity value 

Method (Ibs ai1A) EEC (ppm) (NOAEC) Chronic RQ 

Short grass 

sugarcane 0.027 

(aerial) Tall grass 

Broadleaf plants I Insects 6.64 164 0.04 
The results indicate that for a broadcast application of flufenpyr-ethyl, there are no chronic LOC 

exceedances for birds. 

11. Mammals 

Acute 

Estimating the potential for adverse effects to wild mammals is based upon EFED' s draft 1995 SOP 

of mammalian risk assessments and methods used by Hoerger and Kenaga (1 972) as modified by 

Fletcher et al. (1 994). The concentration of flufenpyr-ethyl in the diet that is expected to be acutely 

lethal to 50% of the test population (LC,,) is determined by dividing the LD,, value (usually rat 

LD,,) by the percent body weight consumed. A risk quotient is then determined by dividing the EEC 

by the derived LC,, value. Risk quotients are calculated for three separate weight classes of 

mammals (15, 35, and 1000 g), each presumed to consume four different kinds of food (grass, 

forage, insects, and seeds). The acute risk quotients for broadcast application of non-granular 

products are tabulated below. 

Table 7: Mammalian Acute Risk Quotients for Multiple Applications of Nongranular Products (Broadcast) Based on a 

Rat LD,, of >5000 mglkg. 

Site1 App. Meth.1 Body Weight (g) % Body Weight Rat LD,, Maximum Residue (ppm) Acute RQ 

Rate in Ibs ai/A Consumed (mgfkg) on short grass 

(No. of Apps.) 

sugarcane I aerial 1 15 95 

0.027 (2) 

35 66 

n/a - when information is not available or when a greater than toxicity value which minimal risk (RQ <0.01) is presumed for the species. 

Since flufenpyr-ethyl is classified as practically nontoxic to mammals (LD50 >5,000 mglkg), the 

acute risk to mammals is believed to be negligible. 

Chronic 

The chronic risk quotients for single (Table 8) broadcast application of non-granular products to 

mammals are tabulated below. 

Table 8: Mammalian Chronic Risk Quotients for Two Applications of Nongranular Products (Broadcast) Based on a 

laboratory rat NOAEC of 1463 ppm in a 2-Generation Reproduction Study. 

SiteIApplication Appl. Rate Food Items Maximum EEC (ppm) NOAEC (ppm) Chronic RQ 

Method (No. Apps.) (EECNOAEC) 

sugarcane 0.027 Ib ai./A Short Grass 

(aerial) (2) 

Tall grass 

Broadleaf 

plantsAnsects 
The results indicate that for two applications of nongranular products at the proposed label rate, there 

are no LOC exceedances for mammals. 

111. Insects 

Currently, EFED does not assess risk to nontarget insects. However, toxicity results for the honeybee 

are used only for recommending appropriate label precautions. Flufenpyr-ethyl is practically non 

toxic to honeybees (LD,, >25 pglbee) on an acute contact basis, precautionary labeling is not 

required. 

IV. Terrestrial Plants 

Risks to terrestrial plants inhabiting dry and semi-aquatic areas are determined based on the amount 

of pesticides present on the soil surface due to runoff, spray drift, or volatilization. EFED's scenario 

for runoff fi-om one treated acre to an adjacent area (sheet runoff) and 10 treated acres to a distant 

low-lying area (channelized runoff) is based on: 1) solubility and the amount of pesticide present on 

the soil surface and its top one inch and 2) the percent of runoff values of 0.01,0.02, and 0.05 for 

water solubility of 40 ppm, 1 0- 100 ppm, and > 100 ppm, respectively. Since the water solubility is 

40 ppm for flufenpyr-ethyl, the runoff value of 1% will be used for calculation. Formulas for 

determining EECs for terrestrial plants as a result of runoff and spray drift are presented in Appendix 

IV. 

Spray drift exposure from ground application is assumed to be 1 % of the application rate. Spray drift 

from aerial, airblast, forced-air, and chemigation applications is assumed to be 5% of the application 

rate. EECs are calculated for the following application methods: (1) unincorporated ground 

applications and (2) aerial, airblast, forced-air, and chemigation applications. In addition to 

considering where plants grow, exposure must be estimated to compare with results from two kinds 

of plant tests - a seedling emergence study (Table 9) and a vegetative vigor study (Table 10). 

Seedling emergence studies involve treating the soil in which seedlings grow, thus exposing the 

growing plant to the pesticide. The vegetative vigor study involves exposing only the foliage of 

actively growing plants off-site to spray drift. Both runoff and spray drift are assumed to reach offsite soil. No method is currently available for estimating chronic exposures to terrestrial plants. 
Table 9. Runoff Risk Quotients from a Single Application for Non-Endangered Terrestrial Plants Based 

On a Lettuce Seedling Emergence EC25 of 0.012 Ib ai/A and for Endangered Terrestrial Plants Based On a 

Lettuce Seedling Emergence NOAEC of 0.0097 Ib ai/A. 

Total Loading (Ib ai/A) Non-Endangered RQ Endangered RQ 

Site A Application Drift (Total LoadindEC25) Total LoadindNOAEC) 

Rate (Ib ai/A) 

(Ibs ai/A) Adjacent Semi-aquatic Dry Semi-aquatic Dry Area Semi-aquatic 

Dw Area1 Area2 Area Area area 

unincorp. 0.027 0.0003 0.0005 0.003 0.03 0.17 0.06 0.3 1 

ground 

aerial 0.027 0.0014 0.0015 0.003 0.08 0.17 0.16 0.31 

A includes all uses except field corn 

Sheet Runoff + Drift 

' Channelized Runoff + Drift 

'exceeds the LOC (RQFl) for non-endangered terrestrial plants 

" exceeds the LOC (RQk 1) for endangered terrestrial plants 

Based on results of the seedling emergence study tested up to 0.029 lb ai per acre tested, risks to 

terrestrial non-target plants fiom runoff are expected to be minimal. For aerial or ground application, 

the non-endangered and endangered species LOCs are not exceeded (RQ <1) for pre-emerged 

terrestrial plants in dry and semi-aquatic areas at the registered maximum single application rate of 

0.027 lb ai per acre. 

Drift risk quotients for endangered and non-endangered terrestrial plants inhabiting dry and 

semi-aquatic areas are presented in the following table. 

Table 10. Drift Risk Quotients from a Single Application for Non-Endangered Terrestrial Plants Based On 

a Tomato Vegetative Vigor EC25 of 0.00009 lb ai/A and for Endangered Terrestrial Plants Based On a 

Tomato Vegetative Vigor NOAEC of 0.00004 lb ai/A. 

Non-Endan~ered RQ 

SiteA Appl. Rate Drift EEC (Total LoadingEC25) 

(single appl.) (Ib ai/A) 

Drift 

Endangered RQ 

Total LoadinpJNOAEC) 

Drift 

unincorporated 0.027 0.0003 

ground 

aerial 0.027 0.0014 15* 34** 

A includes all uses except field corn ' Sheet Runoff + Drift 

Channelized Runoff + Drift 

'exceeds the LOC (RQ1) for non-endangered terrestrial plants 

" exceeds the LOC (RQ> 1) for endangered terrestrial plants 

Based on the vegetative vigor study, exposure from drift to nontarget plants is expected. 

With a toxicity value of 0.00009 lb ai/A for non-endangered plants and 0.00004 lb ai/A for 

endangered plants, the drift LOCs are exceeded with a RO range of 3 to 7 for ground applications 

and a RO range of 15 to 34 for aerial applications when terrestrial plants in offsite areas are exposed 

to flufenpyr-ethyl. However, the LOCs are exceeded based on a single application, EFED assumes 

a greater adverse effect to terrestrial plants with multiple applications. 
Exposure and Risk to Nontarget Aquatic Organisms 

The Tier I EEC values for estimating acute risk are the maximum (peak) values calculated for 

flufenpyr-ethyl applied to field corn, sugarcane and soybean using GENEEC2 (GENeric Expected 

Environmental Concentration model, Version 2; details in Appendix 111). 

For chronic risk, 60-day EECs are used for fish and 21-day EECs are used for invertebrates. EFED 

believes that the proposed use and method of application (aerial), because of their proximity to 

aquatic environments, may result in the direct application of flufenpyr-ethyl to aquatic environments. 

For this use pattern, EFED assumes simple dilution of the amount applied to a surface acre of water 

at depths varying from 6 inches to 6 feet. 

V. Freshwater Fish 

Acute 

Acute risk quotients for multiple broadcast applications of flufenpyr-ethyl to freshwater fish (Table 

11) are tabulated below. 

Table 11. Acute Risk Quotients for Freshwater Fish Based on a Bluegill Sunfish LC,, of 2.537 mg/L. 

Appl. rate No. EEC model LC,, (mg/L) Peak EEC Acute RQ 

Site (Ib ai/A) ~PPI. (EEC1LC50) 

sugarcane 0.027 2 GENEEC2 2.537 0.0003 <0.01 

*** exceeds the LOCs for acute risk (RQ 2 0.5), restricted use (RQ 20.1) and endangered species (RQ 10.05) 

** exceeds the LOCs for restricted use (RQ 20.1) and endangered species (RQ 20.05) 

* exceeds the LOC for endangered species (RQ 30.05) 

nla - when information is not available or when a greater than toxicity value which minimal risk (RQ <O.Ol)is presumed for the species. 

Acute risk to freshwater fish are presumed to be negligible for field corn, sugarcane, and soybean 

uses. There are no LOC exceedances for fi-eshwater fish. 

Chronic 

Chronic risks were evaluated using both maximum and 60-day mean (average) estimated 

environmental concentrations of flufenpyr-ethyl residues (Table 12) to freshwater fish. Based on an 

fish early life-stage toxicity test with flufenpyr-ethyl; the rainbow trout NOAEC is 0.44 mg/L. 

Chronic risk quotients for two aerial broadcast application to fieshwater fish are tabulated below. 

Table 12. Chronic Risk Quotients for Freshwater Fish Based on a Rainbow Trout NOAEC of 0.44 mg/L. 

Appl. rate No. EEC Toxicity value Peak EEC 

Site (Ib aiIA) appl. model 

sugarcane 0.027 2 GENEEC 

2 

+ exceeds the LOC for chronic risk (RQ r 1). 
Based on the early life-stage toxicity test, the flufenpyr-ethyl residue does not exceed the chronic 

LOC for risk to freshwater fish. Minimal risk is presumed for freshwater fish fiom short-term and 

long-term exposures. 

VI. Freshwater Invertebrates 

Acute 

Acute risk quotients for multiple broadcast applications of flufenpyr-ethyl to freshwater invertebrates 

(Table 13) are tabulated below. 

Table 13. Acute Risk Quotients for Freshwater Invertebrates Based on a Daphnid EC,, of >3 mg/L for 

Flufenpyr-ethyl. 

Appl. rate No. EEC EC,, (mg/L) Peak EEC RQ (EEC/Ec50) 

Site (lb ai/A) appl. model (mgk) 

sugarcane 0.027 2 GENEEC2 >3 0.0003 <0.01 

*** exceeds the LOCs for acute risk (RQ 20.5), restricted use (RQ 20.1) and endangered species (RQ 20.05) 

** exceeds the LOCs for restricted use (RQ 20.1) and endangered species (RQ 20.05) 

* exceeds the LOC for endangered species (RQ 10.05) 

n/a - when information is not available or when a greater than toxicity value which minimal risk (RQ <O.Ol)is presumed for the species 

Acute risk to freshwater invertebrates is presumed to be negligible for field corn, sugarcane and 

soybean uses. There are no LOC exceedances since the toxicity of flufenpyr-ethyl is above the water 

solubility limit (>3 mg/L). 

Chronic 

Chronic risks were evaluated using both maximum and 21-day mean (average) estimated 

environmental concentrations of flufenpyr-ethyl residues (Table 14) to freshwater invertebrates. 

Based on an invertebrate life cycle toxicity test with flufenpyr-ethyl; the daphnid NOAEC is 0.46 

mg/L. Chronic risk quotients for multiple broadcast applications to freshwater invertebrates are 

tabulated below to examine instantaneous and long-term exposures. 

Table 14. Chronic Risk Quotients for Freshwater Invertebrates Based on a Daphnid NOAEC of 0.46 mg/L 

for Flufenpyr-ethyl. 

Appl. rate No. EEC 

Site (lb ai/A) appl model 

sugarcane 0.027 2 GENEEC2 

+ exceeds the LOC for chronic risk (RQ 2 1). 

Minimal risk is presumed for freshwater invertebrates from short-term and long-term exposures. 
VII. EstuarineIMarine Fish 

Acute risk quotients for multiple broadcast applications to estuarinelmarine fish (Table 15) are 

tabulated below for use sites from which runoff and drift might contaminate the estuarinelrnarine 

environment. 

Table 15. Acute Risk Quotients for Estuarinelmarine Fish Based on a Sheepshead Minnow LC,, of >2.7 mglL. - - 

Appl. rate Number of EEC Toxicity LC,, Peak EEC Fish RQ 

Site (Ib aUA) applications model (mg/L) (mg/L) (EEC/LC,o) 

sugarcane 0.027 2 GENEEC2 >2.7 mgiL 0.0003 <0.01 

*** exceeds the LOCs for acute risk (RQ 2 0.5), restricted use (RQ 20.1) and endangered species (RQ 20.05) 

Acute risk to estuarinelrnarine fish is presumed to be negligible for sugarcane, field corn and soybean 

uses. There are no LOC exceedances since the toxicity of flufenpyr-ethyl is above the water solubility 

limit (>2.7 mg1L). 

VIII. Estuarine/Marine Invertebrates 

Acute risk quotients for single and multiple broadcast application to estuarinelmarine invertebrates 

(Table 16) are tabulated below for use sites from which runoff and drift might contaminate the 

estuarinelrnarine environment. 

Table 16. Acute Risk Quotients for Estuarinelmarine Invertebrates Based on a Shrimp EC,, of 2.08 mgL. 

Appl. rate No. EEC Toxicity EC,, Peak EEC Shrimp RQ 

Site (lb ai/A) appl. model (mg/L) (mg/L) (EEC/EC,o) 

sugarcane 0.027 2 GENEEC2 2.08 0.0003 <0.01 

Acute risk to estuarinelrnarine invertebrates is presumed to be negligible for sugarcane, field corn 

and soybean uses. There are no LOC exceedances since flufenpyr-ethyl is moderately toxic (2.08 

mg/L) to estuarinelmarine invertebrates. 

IX. Aquatic Plants 

Risk quotients for aquatic plants (Table 17) are addressed below. The assessment for nonendangered and endangered vascular aquatic plants is based on the toxicity of parent flufenpyr-ethyl 

and its degradates to duckweed. The assessment for nonvascular, non-endangered plants uses the 

parent toxicity to the most sensitive algal or diatom species. Currently, there are no Federally listed 

endangered nonvascular aquatic plants. 
Table 17. Acute Risk Quotients for Aquatic Plants based upon Parent and Degradate Compounds. A Duckweed (Lemna 

gibba) EC50 of 0.013,0.006, and 10.03 ppm from Parent Flufenpyr-Ethyl and its Degradates, respectively and a 

Nonvascular Plant (Skeletonema capricornutum) EC50 of 0.009 ppm from the Parent Compound. For Endangered 

Species, the L. gibba NOEC of 0.003,0.0036, and 0.03 ppm from Parent Flufenpyr-Ethyl and its Degradates, 

Respectively. 

Site/ Application 

Method1 

Rate of Application Species 

Endangered 

EEC NOAEC Species RQ Non-target plant 

ECso (PP~) (PP~) (PP~) 'FECmOAEC) RQ (EECIECso) 

(lbs ai/A) 

sugarcanel aerial I duckweed (parent) 0.013 0.0003 0.003 0.10 0.02 

0.027 

duckweed (S1353 acid) 0.006 0.0022 0.003 0.73 0.37 

duckweed (S135340H) >0.03 0.00022 0.03 <0.01 <0.01 

algae or diatom 0.009 0.0003 nla n/a <0.01 

* exceeds the plant LOC for non-target or endangered plants (RQ 21) 

n/a - when information is not available or when a greater than toxicity value which minimal risk is presumed for the species. 

The endangered and non-target aquatic plants LOCs are not exceeded for vascular or non-vascular 

plants with the parent compound. However, for testing with the S1353 acid and S1353-4-OH 

degradates, the non-target and endangered aquatic plants LOCs are not exceeded for the proposed 

label uses on sugarcane, soybean, and field corn. 
Appendix VI Environmental Fate Data requirements 

162- 1 

162-2 

162-3 

162-4 

163-1 

163-1 

163-2 and 163-3 

!64-1 

164-2 

165-4 

Aerobic Soil Metabolism 

Anaerobic Soil 

Metabolism 

Anaerobic Aquatic 

Metabolism 

Aerobic Aquatic 

Metabolism 

Mobility in 

SoilISediments 

Mobility in Soil Columns 

Volatility from Soil 

(Laboratory and Field, 

respectively) 

Terrestrial Field 

Dissipation (Short Term) 

Aquatic Field Dissipation 

Bioaccumulation in Fish 

Yes for S-3 153-acid 

Yes 

NA 

Yes 

NA 

Yes 

NA 

NA 

Yes 

NA 

NA 

45 1 190-22 

NA 

45 1 190-23 

NA 

451191-01 

NA 

NA 

451191-02,03, 

04, & 21 

NA 

NA 

acceptable 

NA 

acceptable 

NA 

acceptable 

NA 

NA 

acceptable 

NA 

NA 
Appendix VII Ecological Effects Date Requirements 

Are Data Study 

Guideline Date Requirements Requirements MRID Classification 

Satisfied? 

71-l(a)(b) Acute Avian LD,, 

7 1 -2(a) Avian DietaryYQuail 

7 1 -2(b) Avian DietaryDuck 

71-3 Wild Mammal Toxicity 

Yes 

Yes 

Yes 

Yes 

Core 

Core 

Core 

Acceptable 

Avian ReproductivefQuail Yes 

Yes 

NA 

Core 

Core 

NA 

Avian Reproductive/Duck 

Actual Field Testing 

(Residue monitoring) 

Fish Toxicity Bluegill Sunfish 

LC50 

Yes Core 

Fish Toxicity Rainbow Trout LC50 Yes 

Yes 

Core 

Invertebrate Toxicity Daphnid Supplemental 

EC50 

EstuarineMarine Toxicity Fish 

LC50 

Yes Core 

EstuarineIMarine Toxicity Mollusk Yes 

Yes 

Yes 

Core 

Core 

Core 

EstuarineJMarine Toxicity Mysid 

Freshwater Aquatic Invertebrate 

Life Cycle 

72-4(c) 

122- 1 (a) 

122- 1 (b) 

122-2 

Freshwater Fish Early Life Stage Yes 

NA 

NA 

Yes 

Supplemental 

NA 

NA 

Core 

Tier I Seed Emergence 

Tier I Vegetative Vigor 

Tier I Aquatic Plant Growth (Algae) 

123-l(a) Tier I1 Seedling Emergence Yes 

123-l(b) Tier I1 Vegetative Vigor Yes 

141-1 Honey Bee Acute Contact Yes 

141-2 Honey Bee Residue on Foliage NA 

Core 

Core 

Core 
4ppendix VIII - EllPate Output 

Chemical Name: gi@e&eyr-q@$i: 

Use 

Formulation 

Terresterial Application Residues I Grass I 

Short Grass 

Tall Grass 

Broadleaf plantshm 

Insects 

Fruitslpodsllg 

insects 

Inputs L I0 

8 '9 Application Rate E 6 .- 

Half-life 4 

2 ,+- Fruitslpodsll Frequency of 0 Application 

Maximum # 

Avian 

Apps.Near 

Outputs 

Maximum 56 day Average 

Concentration Concentration 

(PPM) IPPM) 

Days 

\- - ---, ,- ----3 

11.80 7.48 

5.41 3.43 # days 

6.64 4.21 Exceeded 

0.74 0.47 on short grass 

(in first 56) 

Acute LC50 5000 0 

(PP~) 

Chronic NOAEC 1 64 0 

(PP~) 

Acute RQ Chronic RQ 

(Max. res. mult. 

apps.) 

Short Grass 0.00 0.07 

Tall Grass 0.00 0.03 # days 

Broadleaf plantslsm 0.00 0.04 Exceeded 

Insects 

Fruitslpodsllg 0.00 0.00 on short grass 

insects 

Max Single Application 

which does NOT exceed 

Avian Acute 

Avian Chronic Ib a.i.) 

Mammalian 

Acute 

Mammalian 

Chronic 

(in first 56) 
Mammalian Acute LD50 5000 0 Rat Calcgllated LC-% (ppm) ,w 100(100 , (mglkg bwld) I RChronic NOAEL 1463 0 Rat Calculated NOAEL (ppm) 

(mglkg diet) 

15 g mammal 

Acute RQ 

35 g mammal 1000 g 

mammal 

Rat Acute Rat Chronic 

Acute RQ Acute RQ Dietary Dietary 
Qppendix IX - Terr Plant Output