U. S. ENVIRONMENTALPROTECTIONAGENCY Washington, D.C. 20460 OFFICE OF PREVENTION,PESTICIDES AND TOXIC SUBSTANCES

I DP BARCODE: D270231,D284046 DATE: November 4,2003 CHEMICAL: Flufenpyr-ethyl PC Code 108853 1Sponsor: Valent USA Corporation SUBJECT: 

### Data Review and Addendum for FLUFENPYR-ETHYL (S-3153 

### WDG Herbicide) on Terrestrial Animals, Aquatic Organisms, and Plants. FROM:

THRU:

TO: Stephen Carey, Biologist EnvironmentalRisk Branc Ben Smith, Branch Chief Stephanie Syslo, RAPL EnvironmentalRisk Branch IIIIEFED Dianne Morgan, Review Manager Joanne Miller, PM 23 Herbicide Branch Registration Division

As indicated in our "New Chemical Review for the us? of flufenpyr-ethylon Sugarcane and Soybeans, dated September 11, 2003", our analysis was based on screening level review of the ecological effects studies. We have now completed the peer review of these studies. Copies of each study's data evaluation records (DERs) are attached. Peer review has identified the need for adjustments in the toxicity endpointsoriginallyreported for aquatic vascular plants and for chronic avian effects. In the case of the chronic avian effect level, we previously had projected the potential for chronic risk at 164ppm (a level well above the peak chronic EEC of 12ppm). Subsequent analysis establishes a much higher NOAEC of 1040ppm. Consequently, it is even less likely that flufenpyr poses a chronic avian effect. The other numbers which changed were the effect levels for aquatic vascular plants. In the originalrisk assessment, we reported exceedances of the LOC for terrestrialplants, but had not anticipated any issues with the aquatic plants. In fact, we had not even performed crop specific modeling to devise RQs since the LOC was not exceeded. Subsequent analysis has identified a EC50 for duckweed at 0.013 mg/L and a reduction of the NOAEC from 0.003 mg/L to 0.00078 mg/L. The NOAEC forthe S-3153-aciddegradate decreased from 0.003 mg/L to 0.0003 mg/L.These levels now result in an LOC exceedance for aquatic vascular plants. We, therefore, performed more crop specific modeling of the EEC's. All of the resulting changes in the science chapter which result from these collective changes are identified in green text in the attachments. Based on the changes,the RQs for aquatic vascular endangered plants now vary from 2 to 

### 5 for the three crops of interest. Nevertheless, endangered aquatic vascular plants are unlikely to be found in proximity to the three proposed uses. Consequently,these changes would not appear to be significantfrom the standpoint of risk management considerations, subject to our previously expressed concerns about missing studies. Do not hesitate to contact us if you have any questions relating to this submission.

### Attachment
The EnvironmentalFate and Effects Division (EFED) has completed its review of ecological effects data submitted by Valent U.S.A. Corporation on flufenpyr-ethyl. In addition, degradate studies were also submitted because the parent compound degradesrapidly and is less persistent than the two degradates: S-3153 acid and S-3153-4-OHin the environment. The flufenpyr-ethyl studies included acute avian oral (MRID 451188-15), subacute avian dietary (MRIDs 451188-16 and 45 11 88-17) and chronic avian reproduction (MRIDs 45 1188-18 and 45 11 88-19); acute honeybee contact (MRID 45 1190-18); acute freshwater fish (MRIDs 45 11 88-20 and 45 1188-2 1) and invertebrate (MRID 451 188-23);chronic freshwater fish early life-stage (MRID 451188-27) and invertebratelife-cycle (MRID 45 11 88-26); acute estuarinelmarinefish (MRID 45 1188-22) and invertebrate (MRIDs 451188-24 and 45 1188-25);tier I1 terrestrialplant seedling emergence (MRID 45 1190-16)and tier I1 terrestrialplant vegetative vigor (MRID 45 1190-17);tier I1 aquatic vascular plant (MRID 45 1190-1 I), tier I1 aquatic non-vascular plants (MRIDs 45 1190- 12, -13, -14, -15). The degradates of S-3153 acid (MRID 452423-04) and S-3153-4-OH (MRID 452423-03) tier I1 aquatic plant studies with the duckweed,Lemna gibba, are included as well. Toxicity studies on animals and aquatic plants were conductedusing technical grade active ingredient while studies of terrestrialplants were conductedusing formulated end product (S3 153

### WDG herbicide; 50% a.i.). 

### Tables 

### 1 through 

### 16 (excluding Tables 4 and 5 for mammals) provide a brief summary of each study's toxicity endpoint(s) and classification. As indicated in the memorandum, changes are highlighted as green text. If you have any questionsor comments regarding these studies, please do not hesitate to contact us. 

### Toxicity to terrestrial animals and insects, aquatic organisms, and plants
Table 1. Acute Toxicitv ofFlufen~vr-ethvl to Northern bobwhite. Avian Acute Oral Toxicity 

# - Species %ai Toxicity value Toxicity category MRID no. Study classification Northernbobwhite quail 97 LD50 >22502 mglkg practically nontoxic 45118815 core' (Colinus virginianus) 

### ' Core (study satisfies guideline). Supplemental (study is scientificallysound, but doesnot satisfy guideline)

nomortalityreported
Table 2. Subacute Dietary ToxicityofFlufenpyr-ethyl to Northern bobwhite and Mallard ducks.

Avian Subacute Dietary Toxicity Species % ai Toxicity value Toxicity category MRID no. Study Classification Northernbobwhite quail 97 LC50 >56201ppm practically nontoxic 45118817 core (Colinus virginianus) Mallard duck LC50 >56201ppm practically nontoxic 45118816 core (Anas platyrhynchos) 

### ' nomortalityreportedAvian reproduction studiesusing the TGAI are required for flufenpyr-ethyl because multiple applicationsmay subject birds to repeated or continuous exposure during orpreceding the breeding season. The preferred test species are the mallard duck and northern bobwhite. Results indicate an NOAEC of 1040ppm and an LOAEC of >lo40 

### ppm (Table 3).The guideline (71-4) is fulfilled 

### (MRID 45118818, -19). Table 3. Chronic Toxicity of Flufenpyr-ethyl to Bobwhite quail and Mallard ducks.

Avian Reproduction Species % ai NOAEC (ppm) LOAEC Affectedendpoints MRID no. Study classification
Northern bobwhite 97 1040 >lo40 none Mallard 97 1040 >1040 none 451188-19 core 451188-18 core 

### ' Core (study satisfies guideline). Supplemental (study is scientifically sound,but doesnot satisfy guideline). Invalid (study is scientificallyunsound and does not satisfy guideline).

Table 6. Acute Contact Toxicityof 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 

### ' 33% mortalityin some treatment levelswere reported

Table 7. Acute Toxicityof 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 mgL moderately toxic 45 1188-20 core

Table 8. Chronic Toxicitv of Flufen~vr-ethvl to Freshwater Fish. Freshwater Fish Early Life-Stage Toxicity Under Flow-through Conditions. Soecies %ai NOAEC LOAEC Affected Endwints MRID No. StudyClassification Rainbow trout 96.8 0.44 mg/L 0.92 mg/L growth 451188-27 supplemental' test concentrations were below detectable limits for approximately20 hours on Day 22-23.

Table 9. Acute Toxicityof Flufenpyr-ethyl to Freshwater Invertebrates.

Freshwater Invertebrate Acute Toxicity Under Flow-through Conditions S~ecies % ai EC50 Toxicity category MRID No. Study Classification Water flea 96.8 >3 mg/L nla 451 18823 supplemental1 environmental test conditions were higher than the guidelinerecommendations.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. Studyclassification Water flea 96.8 0.46 mg/L 1.2 mg/L reproduction 45118826 core

Table 11. Acute Toxicityof Flufenpyr-ethyl to EstuarineJMarineFish

Estuarinemarine Fish Acute Toxicity Under Flow-through Condition Species % ai LC50 Toxicity category MRID no. Studyclassification Sheepsheadminnow 97 >2.7 mg/L nla 451 188-22 core

Table 12. Acute Toxicityof Flufenpyr-ethyl to EstuarineIMarine Invertebrates

Estuarinemarine InvertebrateAcute Toxicity Under Flow-through Conditions Species % ai EC50 Toxicity category MRID no. StudyClassification Mysid shrimp - - --- - 97 2.08 ma moderately toxic 45 1188-25 core Eastern oyster (shell deposition) 97 s2mg/L n/a 45 1 188-24 core

Table 13. Toxicityof Flufenpyr-ethyl To Terrestrial Plants using Tier I1 Seedling Emergence.

NontargetTerrestrialPlant Seedling Emergence Toxicity (Tier11) Species % ai EC25 (Ibsai/A) NOAEC Endpoint Affected1 MRID No. StudyClassification
50.0 451 190-16 Monocot-Corn >0.029 0.029 none core Monocot-Oat Monocot-Onion Monocot-Ryegrass Dicot-Soybean Dicot-Lettuce Dicot- Radish Dicot-Cucumber Dicot-Cabbage none weight
none
none weight weight
none weight core
core
core
core
core
core
core
core Dicot- Tomato 20.029 0.029 none core only the most sensitiveendpoint istabulated, Table 14. Toxicityof Flufenpyr-ethyl To Terrestrial Plants using Tier I1 Vegetative Vigor.

NontargetTerrestrial Plant Vegetative Vigor Toxicity (Tier 11) Species % ai EC25 (Ibs ai/A) NOAEC EndpointAffected1 MRID No. Study Classification

Monocot- Corn 20.029 0.029 none core Monocot- Oat >0.029 0.029 none core Monocot- Onion 0.0056 0.0032 height core Monocot- Ryegrass >0.029 0.029 none core Dicot-Soybean >0.029 0.029 none core Dicot- Lettuce 0.00018 0.00004 weight core Dicot- Radish Dicot-Cucumber 0.0021 0.0011 weight 0.00061 0.00012 weight core
core Dicot- Cabbage 0.0023 0.001 1 weight core Dicot- Tomato 0.00009 0.00004 weight core only the most sensitive endpointistabulated 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), andlor by drift (aerial) or that is applied directlyto 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 capricomutum, Anabaenaflos-aquae, and a freshwater diatom. In this case, the registrant chose to conduct Tier I1testing even though it may not have been triggered. Results of Tier I1toxicity testing with the vascular aquatic plant, duckweed, and the most sensitive non-vascular aquatic plant, the EC5Os were 0.013 and 0.009 mg/L respectively 

### (Table 15). The guideline (123-2) is fulfilled with all five species tested 

### (MRID 451190-11, -12, -13, -14, -15). 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 0 13 1ndL' 0.00078 mdL' 451190-11 core Nonvascularspecies:

Anabaena flus-aquae 99.1 >0.5 mg!L1 0.031 rng/L1 451190-14 core Skeletonenla costaturn 97 0.011ma 0.00081 mg/L 451190-12 core Selenastrum capricornutum 99.1 0.009 mg/L1 <0.0063mgL1-? 451 190-15 core Naviculapelliculosa 97 0.18 ma 0.032 mg!L 451190-13 core 

### ' nominal concentration

the NOAEC isbelow the lowest tested concentrationAdditional duckweedtoxicity studies were also submittedby the registrant on flufenpyr-ethyl's degradates, S-3153-acid and S-3153-4-OH.Results of Tier 

### I1 toxicity testing indicate the EC5Os were 0.0063 and >0.03 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) Specles % a1 Degradahon IdenWica~on EC50 (mg a eJL) NOAEC MRIDno Study classificahon Duckweed 98 7 S-3153ac~d 0 0063 0 0003 452423-04 core Duckweed 97 5 S-3153-4-OH SO 03 0 03 452423-03 core

Section 

### A: Summary 

### ofRisks to Birds Page 20 of Science Chapter Toxicity: Flufenpyr-ethylis nontoxic to birds on both an acute (LD,, >2250 mglkg) and subacutedietary basis (LC,, >5620 mglkg of diet). Nor does it pose the risk of adverse effects on a chronic exposurebasis (NOAEC = 1040ppm). Page 11 Risk Characterization for 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 sensitiveto 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. Because the NOAEC is 1040ppm, problems are not anticipated even under a screening level assessment which identifies a peak modeled concentrationof flufenpyr-ethylon short grass of 12ppm. Page 21
Estimates of Risks to Birds and Mammals: 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 10.Table 10 - Toxicity, Exposure, and Risk QuotientValues of Flufenpyr-ethyl(2 applications of 0.027lb ai/A, 10days interval, 35 day half-life) pecies



### f Risk Quotients (ppm) 

### (RO) 

## ' Northern bobwhitel Mallard >2250 mglkg 11.8 <0.01 duck-Oral 

# IMarnmals-Oral and Reproduction 

## 1 >5000 mgkg/ 1463ppm 

## I 11.8 

## 1 ~0.01 / <0.01 

### ' Based on ELLFATEmodel (Detailed in appendixVIII)

Bobwhitaallard-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. >5620ppm 1040ppm

Chronic risks were evaluated using maximum estimated environmentalconcentrationsbased on a Mallard duck NOAEC of 1040pprn (Table 

### 6). Even assuming no degradationbetween 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 (maximumresidue)of Flufenpyr-ethyl (broadcast) based on a Mallard duck NOAEC of 1040 ppm. 11.8 11.8

SiteIApp. App. Rate Maximum Toxicity value Chronic RQ Food Items Method (lbs ai1A) EEC (ppm) (NOAEC) ~0.01 <0.01

Short grass 11.80 1040 <0.01 sugarcane 0.027 (aerial) Tall grass 5.41 1040 <0.01 BroadleafplantsI Insects 6.64 1040 <O.O1 Seeds 0.74 1040 cn nl The results indicate that for a broadcast application of flufenpyr-ethyl, there are no chronic LOC exceedances for birds.

Section 

### B: Summary of Risks to Aquatic Plants Page 18 Flufenpyr-ethyl was shown to be moderately toxic to freshwaterfish (LC,, = 2.5 - 3.75 ppm) and estuarinelmarineinvertebrates(EC,, = 2.08 ppm) on an acute basis. However, the toxicity of flufenpyr-ethylto freshwaterinvertebrates and estuarinelmarinefish was not seen at the solubility limit in aquatic environments (4.1 pprn in water). Based on the Tier 

### I1 duckweedtoxicity testing, the EC,, values of the parent flufenpyr-ethyl and its degradates S-3153 acid and S-3153-4-OH were 0.013,0.006, and >0.03 ppm, respectively. The Tier I1 non-vascular aquatic plants toxicitytesting with the parent compound showsfreshwater green alga (Selenastrumcapricomutum) as the most sensitive non-vascular plant, with an EC,, of 0.009 ppm. Although chronic values were not determinedfor estuarinelmarinefish; freshwater early life stage and invertebratelife cycle values (NOAECILOAEC)were shown to be 0.4410.92 ppm and 0.4611.2 ppm, respectively,with significantreductions 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 l-fold. None of the aquatic organisms and plants were adversely affectedby the solvent in these tests. Page 12 Results from this risk assessment indicate that aquatic plants (vascular and non-vascular) are not likely to be exposed to parent flufenpyr-ethylat levels of concern. No LOCs were exceeded for aquatic plants and potentialrisk is expected to be minimal for the parent compound, however, Ler~zna gihha results with the degradate S-3153-acid produce an LOC exceedance for endangered species. No aquatic non-vascular plant studies with the degradates have been submitted to the Agency, therefore, risks to non-vascular plants are unknown. Page 19 Estimates of Risks to Aquatic Organisms and Plants A means of integratingthe 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.

The toxicity test values (i.e., measurement endpoints) used in the acute and chronicrisk quotients are derived from the results of required studies. The EEC, toxicity, and risk quotient values are provided below in Table 8.



## IDaphnia magna-Acute 

## I >3 

## 1 0.00028 Table 8 - Toxicity, Exposure, and Risk Quotient Values of Flufenpyr-ethyl (based on two aeria 0.027 lb aiIA, 10days interval)

Daphnia magna-Chronic 

# I 1.2 0.00019 I Species
Rainbow trout-Acute


## IRainbow trout--EarlyLife Stage 

## I 0.92 

## I 0.OOOl Toxicity

(PP~)

2.5 Exposure1 (PP~) 0.00028

Estuarinelmarinefish- Acute Shrimp -Acute application of

-- - >2.7 2.08 

# I 0.00028 Eastern Oyster--Shell deposition Risk Quotient (RQ) 

# I

0.00028

>2 0.00028Aquatic Plants- Anabaena jlos-aquae 

# I >0.05 

# 1 0.00028 

# 1 ~0.01 surface water concentrations (EECs) are shown in ppm. Aquatic Plants-Duckweed (parent) Aquatic Plants-Duckweed (S3153acid) -Soybean (MS) Aquatic Plants-Duckweed (S3153acrd)

- Sugarcane (FL) Aquatic Plants-Duckweed (S3153acid)

- Sugarcane (LA) Aquatic Plants-Duckweed (S315340H) Aquatic Plants- Selenastrum capricornutum Aquatic Plants- Navicula pelliculosa Aquatic Plants- Skeletonema costatum

Risk Assessment Summary:

As shown in 

### table 8, no LOCs were exceeded for aquatic organisms exposed to parent flufenpyr-ethyl and aquatic plants exposed to parent flufenpyr-ethyl and S-3153-4-08degradate. Therefore, risks to fish, invertebrates,and aquatic plants from parent flufenpyr-ethyl are believed to be negligible. Also, since flufenpyr-ethyl is not persistent (half life

# - 7 days) in aquatic environments, exposure from this scenario based on GENEEC2modeling with peak (acute) value of 0.3 ppb for parent flufenpyr-ethyl should not present a concern for any aquatic organisms from the proposed use sites of sugarcane and soybean since the toxicity values are at or greater than 

### 440 ppb. Importantly,LOCs were exceeded for aquatic vascular plants exposed to its degradate, S-3153-acid. However, exposure from same scenario as above based on PRZM-EXAM modeling with peak values of 0.6, 1.06, and 1.58ppb for S-3153-acidapplied to sugarcanein Florida and Louisiana and soybeans in Missouri present a concern for aquatic plants. At the chronic level, reproductive effects and growth effects were identified

### in freshwater 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 exposureprofile for each proposed use of flufenpyr-ethyl differs from the constant exposure in the flow-through test because of rapid degradationof parent flufenpyr-ethyl. The significance of the unrealistic constant concentrationin the flow-through test is not completelyclear. 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,dLC,, concentrationwere necessary to cause the effects, or if a shorter exposure at that parent concentrationwould sufice. Regardless, risk quotients did not exceed levels of concern. 0.013 0.006
0.006
0.006
>0.03 0.009 0.16 0.012 0.00028 0.000653
0.00108
0.00158
0.0002 0.00028 0.00028 0.00028 0.02 0.1
0.18
0.26
<0.01 0.03 <0.01 0.02

### Page 76
Table B. Acute Risk Quotients for Aquatic Plants based upon Parent and Degradate Compounds. A Duckweed (Lemna gibba) EC,, of 0.013,0.006, and >0.03 ppm from Parent Flufenpyr-Ethyl and its Degradates, respectively, and a Nonvascular Plant (Skeletonema capricornutum) EC,, of 0.009 ppm from the Parent Compound. For Endangered Species, theL. gibba NOAEC of 0.00078, 0.0003, and 0.03 ppm from Parent Flufenpyr-Ethyl and its Degradates, Respectively. Site/Application Endangered Method/ EGO (PP~) EEC NOAEC SpeciesRQ Non-target plant Rate ofApplication Species Model (PP~) (ppm) (EEUNOAEC) RQ (EECIEC,,,) sugarcane/aerial 1 duckweed GENEEC2 0.013 0.0003 0.00078 0.39 0.02 0.027 (parent) soyhcan (MS) duckweed PRZM- 0.006 0.000653 0.0003 2.17 0.10 (S1353 acid) EXAM

sugarcane (LA) PRZM- 0.006 0.001 06 0.0003 -3.50 0.18 EXAM PRZM- 0.006 0.00158 0.0003 5.30 0.26 EXAM sugarcane I aerial duckweed GENEEC2 >0.03 0.00022 0.03 <0.01 <0.01 (S135340H) sugarcane I aerial algae or diatom GENEEC2 0.009 0.0003 n/a n/a 0.03 (parent) * exceeds the plant LOC for non-target or endangered plants (RQ 21) n/a- when information is not availableor when a greater than toxicity value which minimal risk is presumed for the species.
The 

### endangered and non-target aquaticplants LOCs 

### are not exceeded 

### for vascular 

### or nonvascular plants with the 

### parent compound (S-3153) or S-3153-4-OH.

### However, for testing with the S3153 acid, the endangered species LOC is exceeded but the non-target LOC is not exceeded for aquatic vascular plants 

### for the 

### proposed label 

### uses 

### on sugarcane, soybean, 

### and field corn.