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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

PC Code: 123001

DP Barcode: 427466

December 09, 2015

MEMORANDUM

Subject: Problem Formulation for the Registration Review Environmental Fate and 

Ecological Risk of Flumetralin

To: Katherine St. Clair, Chemical Review Manager 

Kevin Costello, Branch Chief

Risk Management and Implementation Branch 2

Pesticide Re-Evaluation Division (7508P)

From: Brian D. Kiernan, Biologist

Ibrahim Abdel-Saheb, Environmental Scientist

Environmental Risk Branch 6

Environmental Fate and Effects Division (7507P)

Through: Mark Corbin, Branch Chief

Monica Wait, RAPL

Environmental Risk Branch 6

Environmental Fate and Effects Division (7507P)

The Environmental Fate and Effects Division (EFED) has completed the problem formulation (PF)

for the upcoming environmental fate and ecological risk for the registration review of the plant 

growth regulator flumetralin (PC Code 123001).

Flumetralin is registered for use as a systemic plant growth regulator (PGR) intended to control axillary 

growth (suckers) in tobacco crops.

The use pattern for flumetralin has not changed since the Reregistration Eligibility Decision (RED) in 

2007 and there have been minimal new data submitted to EPA since that time; however, data gaps 

remain. This document contains a preliminary risk review based on the currently available data. This 

will serve as a basis for the preliminary risk assessment which will be conducted when the existing 

data gaps have been addressed.
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Taxa considered potentially at risk based on the provisional assessment are listed fish from acute 

exposure, birds and mammals from chronic exposure, and terrestrial plants. There are no data for 

aquatic nonvascular plants, and therefore risk would be presumed.

Data Gaps

The environmental fate dataset for flumetralin is sparse. An acceptable study has been submitted 

only for hydrolysis, and supplemental studies have been submitted for aerobic and anaerobic soil 

metabolism, soil mobility, and fish bioaccumulation.

The required studies under 40 CFR Part 158 include:

Environmental Fate

• Aquatic Photolysis (835.2240)

• Soil Photolysis (835.2410)

• Aerobic Aquatic Metabolism (835.4300)

• Anaerobic Aquatic Metabolism (835.4400)

• Terrestrial Field Dissipation study (835.6100)

• Enforcement Analytical method for Water and corresponding independent laboratory 

validation (ILV) (850.6100)

• Enforcement Analytical Method for Soil and corresponding ILV (850.6100)

Ecological Effects

• Flumetralin use may be of exposure concern for pollinators visiting off-site plants that are 

contaminated by spray drift. Acceptable toxicity data to honey bee adults and larvae have not 

been submitted for flumetralin and these data are needed to fulfill EPA’s recent policy on 

pollinator protection1. A Tier I study on the toxicity of residues on foliage (OCSPP 850.3030)

is not needed since results of the honey bee acute contact LD50 is >100 μg a.i./bee, well above 

the 11 μg a.i./bee trigger criterion. The following six Tier I, II and III honey bee studies, yet to 

be submitted for flumetralin, are required2

: 

o Honeybee adult and larval acute oral toxicity study (following OECD 237, Tier I)

o Honeybee adult 10-day chronic oral (special study; Tier I)

o Honeybee larval repeated dose study (special study renamed as honeybee larval 

chronic oral toxicity study, Tier I)

o Semi-field testing for pollinators (special study, Tier II). 

o Field testing for pollinators (OCSPP 850.3040, Tier III)

o Field trial of residues in pollen and nectar (special study, Tier III)

 1 (Guidance for Assessing Pesticide Risks to Bees, 06.23.2014; signed by Donald Brady, Director, EFED; 

http://www2.epa.gov/sites/production/files/2014-06/documents/pollinator_risk_assessment_guidance_06_19_14.pdf) 2 The need for higher Tier semi-field and full field pollinator studies for flumetralin will be determined after review of 

these Tier I studies.
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Note that it is possible to conduct the larval chronic oral study in such a way as to derive both 

an LD50 (acute endpoint of interest) and a NOAEC (chronic endpoint of interest) from a single 

study. If the chronic larval toxicity study is conducted in such a way that it derives both an 

LD50 and NOAEC, then a separate acute larval toxicity studies are not needed. For pollinator 

studies without finalized guidelines, protocols should be submitted for EPA review and 

comment prior to study initiation.

• Aquatic nonvascular plants (Guidelines 850.4500, 850.4550). While data on green algae are 

used provisionally in this review (FOOTPRINT database; 

http://sitem.herts.ac.uk/aeru/footprint/), the underlying study has not been reviewed by EPA. 

This study should be submitted for EPA review. Further, three (cyanobacteria, centric diatom, 

pinnate diatom) other taxa of aquatic nonvascular species are necessary to complete a risk 

assessment. 

• Avian acute oral toxicity (Guideline 850.2100). Data have not been submitted for a passerine 

species exposed to flumetralin, under the 40 CFR Part 158 data requirements. Although the 

available bobwhite quail study indicates flumetralin has low toxicity to upland game bird 

species, it is uncertain whether passerines may be more or less sensitive to this chemical as a 

result of their higher metabolic rate and differing metabolic pathways. Given the reproduction 

effects of number of survivors, hatchlings, viable embryos, and live embryos observed in birds, 

EFED cannot preclude the potential risk to passerines which are small-sized birds.
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Problem Formulation for the Environmental Fate and Ecological 

Risk in Support of the Registration Review of Flumetralin

N-(2-chloro-6-fluorobenzyl)-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine

CAS Registry Number: 62924-70-3

PC Code: 123001

Prepared by:

Brian D. Kiernan, Biologist

Ibrahim Abdel-Saheb, Environmental Scientist U. S. Environmental Protection Agency

 Office of Pesticide Programs

 Environmental Fate and Effects Division

 Environmental Risk Branch VI

 1200 Pennsylvania Ave., NW

 Mail Code 7507P

 Washington, DC 20460

Reviewed by:

Nathan Miller, Biologist 

William P. Eckel, Ph. D., Senior Science Advisor

Monica Wait, RAPL

Mark Corbin, ERB6 Chief

December, 2015

Office of Chemical Safety 

and Pollution Prevention
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Contents

1. Introduction............................................................................................................................. 6

2. Conclusions............................................................................................................................. 6

2.1. Ecological Risk Assessments.......................................................................................... 6

2.3. Clean Water Act Programs............................................................................................... 8

3. Environmental Fate and Transport............................................................................................. 8

3.1. Transformation Products................................................................................................ 11

4. Receptors and Effects ........................................................................................................... 11

4.1. Effects to Aquatic Organisms ........................................................................................ 12

4.2. Effects to Terrestrial Organisms .................................................................................... 13

4.3. Ecological Incidents....................................................................................................... 14

5. Exposure Pathways of Concern ............................................................................................ 15

6. Analysis Plan ........................................................................................................................... 15

6.1. Stressors of Concern....................................................................................................... 15

6.2. Measures of Exposure ................................................................................................... 15

6.4 Preliminary Risk Review ............................................................................................... 17

7. Federally Threatened and Endangered (Listed) Species Concerns....................................... 19

8. Endocrine Disruptor Screening Program (EDSP)............................................................... 20

9. Environmental Fate and Ecological Effects Data ................................................................. 20

9.1. Environmental Fate............................................................................................................ 20

9.2. Effects................................................................................................................................ 22
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1. Introduction

EFED evaluated the most recent ecological risk assessments for flumetralin in association with 

the updated toxicity, exposure, and usage information to determine if sufficient data are available 

and if further updates are needed to support registration review. With few new data submitted 

and no new actions since the EFED reregistration eligibility decision (RED) chapter issued in 

2007, EFED proceeded with a preliminary risk review using the latest EPA science policies and 

risk assessment methodologies based the data currently available for flumetralin. 

Flumetralin is used as a plant growth regulator on tobacco crops. Flumetralin is applied as a

post-emergent plant growth regulator on tobacco crops to control the growth of axillary buds 

(suckers) after removal of the apical meristem (‘topping’), thus forcing the plants to expend 

energy in growing the existing leaves larger, rather than in new growth. The specific mechanism 

of action is not well documented. It is applied once per growing season by ground or handheld 

spray, or in some cases, dropline or jug applications. Applications are made when “most tobacco 

plants are in the elongated button to early flower stage,” when topping typically occurs. Timing 

of topping varies by region, but generally occurs between June and August.

Flumetralin has been registered since 1983 for this use only, and is undergoing registration 

review in the United States. There are currently three Section 3 technical products and four 

active end-use products registered for flumetralin. The labels allow application at a maximum 

rate of 1.2 pounds of active ingredient per acre (lb a.i./A). A 2015 Screening Level Usage 

Analysis performed by BEAD showed that between 2004 and 2012 an average of 35 percent, and 

up to 55 percent, of tobacco crops were treated with flumetralin. Between 2009 and 2013, 

approximately 103,000 pounds of flumetralin were applied at an average application rate of 0.6 

lbs a.i./A over 170,000 acres annually. 

While overall usage has increased in recent years, the geographic distribution of application has 

remained fairly consistent. From 2003 to 2007 and 2008 to 2013 over half of flumetralin was 

applied in North Carolina, followed distantly by Kentucky and Virginia, with the remaining 15 

percent of usage split between six to ten other states. The average percent crop treated (PCT) for 

use of flumetralin on tobacco during 2007 was 35% for burley tobacco and 60% for dark 

tobacco. 

2. Preliminary Risk Conclusions

2.1. Ecological Risk Assessments

The Agency previously conducted an ecological risk assessment for flumetralin during 

reregistration, EFED’s RED chapter issued in 2007 (July 10, 2007; D326441). The major 

ecological conclusions presented in the previous risk assessment were as follows:
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Table 1. Summary of Risk Concerns Identified for Flumetralin in Previous Assessments

Uses Taxa with 

Acute LOC 

Exceedances

Taxa with 

Chronic 

LOC 

Exceedances

Taxa with 

No LOC 

Exceedances

Bioconcentration? Persistence Degradates 

of Concern

Tobacco Terrestrial 

and aquatic 

plants

Birds and 

their 

surrogates1

, 

mammals, 

listed fish

Terrestrial 

invertebrates2, 

aquatic 

invertebrates

No, based on 

KABAM

No None

1 Chronic risk presumed for birds due to lack of data.

2 Based on acute contact toxicity with adult bees; recent data requirements outstanding.

As a result of the preliminary risk review for Registration Review, EFED determined that 

flumetralin exposures to aquatic organisms continue to be minimal because the new aquatic 

EECs (Estimated Environmental Concentrations) are similar to previous calculated EECs. 

Hence, discussions of risks to aquatic organisms have not been updated in this document, but 

rather are summarized from the RED. Details of the aquatic risk conclusions can be found in the 

2007 EFED RED chapter. 

• Fish and Aquatic Invertebrates: There are no acute or chronic risks indicated for

nonlisted fish and invertebrates, although the listed species LOC is exceeded for acute 

risk to freshwater fish. There are no data examining effects of chronic exposure to 

estuarine/marine animals; however, the fish endpoint would need to be half that for 

freshwater fish for there to be an exceedance and the invertebrate endpoint would need to 

be lower still. 

• Aquatic Plants: There are no LOC exceedances for aquatic vascular plants based on 

Lemna gibba data. There are no Agency-reviewed data for the effect of flumetralin on 

aquatic nonvascular plants and adverse effects are assumed.

For terrestrial animals, the avian chronic risk conclusions will change from the RED due to 

submission of new data. Previously risk to birds from chronic exposure was assumed. While the 

new data results in an upper-bound RQ of 1.2 (exceeding the LOC of 1.0), the exceedance is 

only for birds foraging on short grass. The potential risk to mammals remains similar to that 

described in the previous assessment, with RQs up to 8.3. Terrestrial plants, as expected, remain 

a concern. 

• Birds: There are no acute LOC exceedances for birds; because the endpoints are nondefinitive (greater than the highest dose) RQs are not calculated and risk is presumed to 

be low. Only the upper-bound chronic RQ for foragers on short grass (1.2) exceeds the 

LOC. Chronic risks were presumed in the RED due to lack of avian reproduction data. 

Reproduction data are now available and have been reviewed by EPA (MRIDs 48800302 

and 48800301).
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• Terrestrial-phase Amphibians and Reptiles: Terrestrial-phase amphibians and reptiles 

were not assessed previously. EFED currently uses surrogate data (birds) for terrestrialphase amphibians and reptiles when taxa-specific data are not available. There were no 

LOC exceedances for birds via the oral and dietary routes; these findings also apply to 

terrestrial-phase amphibians and reptiles. 

• Mammals: There are no acute concerns for mammals; there were no effects seen in the 

available acute dose study. RQs are not calculated but risk is presumed to be low. 

However, as described in the previous assessment, there is potential risk to mammals 

from chronic exposure, with RQs up to 8.3.

• Terrestrial Invertebrates (Pollinators): Terrestrial invertebrates were previously not 

assessed quantitatively. Based on the available acute contact study, effects to terrestrial 

invertebrates are not expected. However, acute dietary risk to adult honeybees cannot be 

ruled out. Chronic dietary risk to adult honeybees and acute and chronic dietary risk to 

larval honeybees is uncertain due to a lack of data. While tobacco is very attractive to 

pollinators when in bloom, topping (which removes the inflorescence) limits the 

availability of flowers on the crops. 

• Terrestrial Plants: Flumetralin is expected to adversely affect sensitive terrestrial plants, 

with RQs up to 22 for non-listed plants and 28 for listed species. 

2.3. Clean Water Act Programs 

Flumetralin is not identified as a cause of impairment for any water bodies listed as impaired 

under section 303(d) of the Clean Water Act. No Total Maximum Daily Load (TMDL) criteria 

have been developed for flumetralin. No aquatic benchmarks have been established for 

flumetralin and are not available at 

http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm. Any data submitted or 

otherwise located as part of the registration review process may be used to update aquatic life 

benchmarks if applicable. 

3. Environmental Fate and Transport

Based on Koc values, flumetralin is hardly mobile to immobile (FAO Mobility Classes; Koc range 

of 24,000-183,000) and is very persistent in aerobic soil, with a half-life longer than 3 years in

one foreign soil. In an anaerobic foreign soil, flumetralin degraded with a half-life of 42 days. 

Soil metabolism data obtained using U.S. soils are classified as "not acceptable." Flumetralin is 

stable to hydrolysis. All data submitted for photodegradation (in water and on soil) were not 

acceptable, so it is unknown whether that might be a significant potential route of degradation in 

the environment. Although both of the submitted terrestrial field dissipation studies were 

classified as "unacceptable" for multiple reasons, the available parent concentration data indicate 

that persistence and accumulation of the parent compound may be expected in the field. 

The log Kow of 5.45 indicates a high potential to accumulate in such organisms; however, the 

available BCF data indicates differently (Table 2). Flumetralin has low volatility and low water 
Page 9 of 27

solubility. The only information available on flumetralin degradates was obtained from the 

anaerobic soil metabolism study conducted on a foreign (U.K.) soil. A major degradate, COA275536 (chemical name was not provided; structure presented in Appendix I) was detected at a 

maximum of 33% of the applied (60 days post-flooding). A minor degradate, CGA-276432, was 

detected at a maximum of 2% of the applied (60 days post-flooding). In that study, bound 

residues were a maximum of 18% at 60 days post-flooding and volatiles were negligible. In 

anaerobic soil, flumetralin appears to degrade via sequential reduction of the nitro (NO2) group 

to amines (NH2) to yield the major degradate CGA-275536 (an aniline) and the minor degradate 

CGA-276432, with formation of additional unidentified minor polar/nonpolar products and 

bound soil residues.

There is a potential for flumetralin to reach surface water through spray drift, as the compound 

may be applied by ground spray. Because flumetralin is persistent in surface soils, there is also 

the potential for it to reach surface water through surface runoff either in solution or adsorbed to 

the soil. Based on the high adsorption coefficients, it is unlikely that there wil1 be significant

contamination of surface water with flumetralin through subsurface flow. Because most soils

used to grow tobacco undergo conventional tillage, flumetralin remaining on surface soils should 

eventually be transferred to subsurface soils where it could be expected to degrade or remain

adsorbed to soil.

Based on the results of a terrestrial field dissipation study, in which leaching was observed (to 

15-30 cm), flumetralin appears to have some potential to leach to groundwater. However, these

results conflict with those from the laboratory mobility studies which indicate high levels of

adsorption to soil and, therefore, little or no mobility in soil. The potential to leach may be 

greater when there is excessive rainfall or irrigation, particularly if either of these occurs close to 

the time of application, or if the soil conditions allow for paths of preferential flow. Also, 

because adsorption is highly correlated to organic matter content, there may be a greater 

potential for leaching in lower organic matter soils, such as those used to grow tobacco.

A selection of flumetralin environmental fate and transport properties is summarized in Table 2

below.

Table 2. Physical Chemical and Environmental Fate Properties of Flumetralin.

Parameter Value Source

Selected Physical/Chemical Parameters

Chemical Structure

Empirical Formula http://pubchem.ncbi.nlm.nih.
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Table 2. Physical Chemical and Environmental Fate Properties of Flumetralin.

Parameter Value Source

C16H12ClF4N3O4 gov/compound/flumetralin#s

ection=Top

IUAPC Name

dinitrophenyl-U-14C]labeled N-(2-chloro-6-

fluorobenzyl)-N-ethyl-a,a,atrifluoro-2,6-dinitro-ptoluidine 

http://pubchem.ncbi.nlm.nih.

gov/compound/flumetralin#s

ection=Top

CAS Name

chloro-N-[2,6-dinitro-4-(trifluoromethyl)phenyl]-

N-ethyl- 6-fluorobenzenemethanamine

http://pubchem.ncbi.nlm.nih.

gov/compound/flumetralin#s

ection=Top

CAS No.

62924-70-3 http://pubchem.ncbi.nlm.nih.

gov/compound/flumetralin#s

ection=Top

PC Code No. 123001

SMILES string:

CCN(CC1=C(C=CC=C1Cl)F)C2=C(C=C(C=C2[

N+](=O)[O-])C(F)(F)F)[N+](=O)[O-]

http://pubchem.ncbi.nlm.nih.

gov/compound/flumetralin#s

ection=Top

Molecular Weight 

g/mol

421.7 http://pubchem.ncbi.nlm.nih.

gov/compound/flumetralin#s

ection=Top

Vapor pressure 2.4 x 10-7 Torr (0.032 mPa) Pesticide Manual, 10th Ed., 

Brit. Crop Protection Council, 

and The Royal Soc. of Chem. 

1994

Aqueous solubility 

(20°C)

0.07 mg/L Pesticide Manual, 10th Ed., 

Brit. Crop Protection Council, 

and The Royal Soc. of Chem. 

1994

Henry’s Law Constant 1.9E-6 atm-m3-mole-1 Calculated from vapor 

pressure, Solubility and 

molecular wt.

Log Kow at pH 7 5.45 Pesticide Manual, 10th Ed., 

Brit. Crop Protection 

Council, and The Royal Soc. 

of Chem. 1994

Persistence

Hydrolysis half-life 

(pH 5, 7, 9)

Stable MRID41761508

Aqueous photolysis 

half-life (d)

No Data

Aerobic soil 

metabolism half-life 

(d)

1220 MRID 42566201a

Anaerobic soil

metabolism half-life 

(d)

42 MRID 42566201b

Anaerobic aquatic 

metabolism half-life

No Data

Aerobic aquatic 

metabolism half-life 

(total system)

No Data

Terrestrial Field 

Dissipation half-life 

(days)

The rate of dissipation of flumetralin could not be 

determined. Both studies are classified as not 

acceptable.

MRID 43014002; MRID 

43014003.
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Table 2. Physical Chemical and Environmental Fate Properties of Flumetralin.

Parameter Value Source

Bioaccumulation in 

Fish

612 MRID 43014003; Acc # 

001117114; MRID 

48148701

Mobility

Adsorption/desorption Organic Carbon Normalized Soil Partition 

Coefficient (Koc): 28846, 51100, 182776, 23875

MRID 41761512

3.1. Transformation Products

The only information available on flumetralin degradates was obtained from the anaerobic soil 

metabolism study conducted on a foreign (U.K.) soil. A major degradate, COA-275536 (chemical 

name was not provided; structure presented below) was detected at a maximum of 33% of the 

applied (60 days post-flooding).

4. Receptors and Effects

In screening-level ecological risk assessments, the effects characterization describes the types of 

effects a pesticide can potentially produce in an animal or plant. This characterization is 

generally based on registrant-submitted studies that describe acute and chronic effects 

information for various aquatic and terrestrial animals and plants; however, these data may also 

be supplemented by data reported in ECOTOX that have met Agency criteria for acceptability. 

Toxicity data reported in this section does not include all species potentially affected by 

flumetralin use. Only a few species for fish, aquatic invertebrates and birds are used to represent 

all species in flumetralin use areas. For mammals, toxicity studies are limited for the laboratory 

rat. Also, neither reptiles nor amphibians are tested. The risk assessment assumes that estimates 

of risks to avian species are protective of reptilian and terrestrial-phase amphibians. The same 

assumption is used for fish and aquatic-phase amphibians. Terrestrial plant data are derived 

from the vegetative vigor and seedling emergence tests, typically on 10 agricultural crop species. 

Typically, one vascular aquatic plant (Lemna gibba) and four aquatic nonvascular plant species 

are used to represent potential toxicity to all aquatic plant taxa.

Most of the studies with non-target organisms were conducted with flumetralin technical. A

typical end-use product (TEP), Prime+®, was the test material in the terrestrial plant seedling 

emergence and vegetative vigor studies. These studies provide the effects basis for risk 
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estimation. Tables 3 and 4 provide summary of the aquatic and terrestrial toxicity data used to 

characterize the potential ecological effects of flumetralin. Avian reproduction studies have been 

submitted since the last risk assessment, and study summaries are provided below. 

4.1. Effects to Aquatic Organisms

Table 3. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies 

for Flumetralin

Taxonomic 

Group

Study 

Type

Surrogate 

Species

Toxicity Value

(μg a.i./L)

Acute Toxicity 

Classification 

or Adverse 

Effect 

Observed

Source

(Study 

classification)

Freshwater fish1

Acute

Bluegill sunfish 

(Lepomis 

macrochirus)

LC50 = 23 Highly toxic 43456601

(Acceptable)

Chronic 

Fathead minnow 

(Pimephales 

promelas)

NOAEC = 0.77 Length and 

weight

00116598

(Acceptable)

Freshwater 

invertebrates

Acute

Water flea 

(Daphnia magna)

EC50 > 160 No more than 

Highly toxic

43456602

(Acceptable)

Chronic NOAEC >8.8 None 00116600

(Acceptable)

Estuarine/marine 

fish

Acute

Sheepshead 

minnow

(Cyprinodon 

variegatus)

LC50 > 250 No more than 

Highly toxic

43456603

(Acceptable)

Chronic No data -- --

Estuarine/marine 

invertebrates

Acute Mysid shrimp

(Mysidopsis 

bahia)

LC50 = 93 Highly toxic 43456605

(Acceptable)

Chronic No data -- --

Aquatic plants 

and algae

Vascular Duckweed 

(Lemna gibba)

EC50 >160

NOAEC = 16 biomass 43456606(Acceptable)

Nonvascular No data No data -- --

1 Freshwater fish may be surrogates for aquatic-phase amphibians.
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4.2. Effects to Terrestrial Organisms

Table 4. Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for 

Flumetralin

Taxonomic 

Group

Study Type Surrogate 

Species

Toxicity Value Acute Toxicity 

Classification or 

Chronic Effects 

Observed

Source 

(Study classification)

Birds1

Acute oral Passerine No data N/A No data

Acute oral Bobwhite 

quail (Colinus 

virginianus)

LD50 >2150 mg a.i./kgbw

Practically nontoxic00094016

(Acceptable)

Subacute 

Dietary

LC50 >4800 mg a.i./kgdietPractically nontoxic00094018

(Acceptable)

Chronic2

Bobwhite 

quail (Colinus 

virginianus)

Mallard duck 

(Anas 

platyrhynchos)

NOAEC = 366 mg 

a.i./kg-diet 

LOAEC = 913 mg 

a.i./kg-diet

NOAEC = 243 mg 

a.i./kg-diet 

LOAEC = 493 mg 

a.i./kg-diet

Hatchlings per 

live embryo

Hatchling 

weights, 14d 

survivor weight, 

adult female 

weight gain 

48800302 (In review)

48800301 (In review)

Mammals

Acute Oral

Laboratory rat

LD50 >5000 mg a.i./kgbw Practically nontoxic 00093998

Chronic NOAEL = 300 mg 

a.i./kg-diet 

~10% decrease 

in parental 

weight

00149532

Terrestrial 

invertebrates

Acute Contact -

Adults

Honey bee 

LD50 > 100 μg a.i./bee Practically nontoxic

41761507

(Acceptable)

Acute Oral -

Adults No data N/A No data

Acute Oral -

Larval No data N/A No data

Chronic Oral –

Adults No data N/A No data

Chronic Oral -

Larval No data N/A No data

Terrestrial 

plants

Seedling 

Emergence

Non-grass 

(Tomato)

IC25 = 0.039 lb a.i./A

NOAEC = 0.019 lb 

a.i./A

biomass

4141847001 

(Acceptable) Grass 

(ryegrass)

IC25 = 0.006 lb a.i./A

NOAEC = 0.0048 lb 

a.i./A

height

Vegetative 

Vigor

Non-grass 

(Tomato)

IC25 = 0.014 lb a.i./A

NOAEC = 0.0048 lb 

a.i./A

height

41847002

(Acceptable) Grass 

(ryegrass)

IC25 = 0.027 lb a.i./A

NOAEC = 0.019 lb 

a.i./A

biomass

1 Birds represent surrogates for terrestrial-phase amphibians and reptiles. 2 Data received since the 2007 assessment.
Page 14 of 27

Avian reproduction

The only new ecological effects data received since the RED are from chronic exposure 

reproduction studies for bobwhite quail (Colinus virginianus) and mallard duck (Anas 

platyrhynchos). The submission of these studies addressed an important data gap identified in 

the RED.

A one-generation reproductive toxicity of flumetralin to 16 pairs per dose level of 22 weeks old 

northern bobwhite (Colinus virginianus; MRID 48800302 in review) was assessed over 21 

weeks. Flumetralin was administered to the birds in the diet at mean-measured concentrations of 

<LOQ (<20, control), 145, 366, and 913 mg ai/kg diet. No mortalities or signs of toxicity that 

were related to the treatment were observed in the control or any of the treatment groups during 

the 21-week study. No treatment-related effects were observed for feed consumption or changes 

in adult or offspring body weight. There was a statistically significant, dose-dependent reduction 

in the number of hatchlings per live embryo (Jonckheere-Terpstra, p = 0.0484, 7.71% reduction 

relative to the control) at the highest treatment level. Therefore, the NOAEC is 366 mg ai/kg 

diet.

A one-generation reproductive toxicity of flumetralin to 16 pairs per level of 20 weeks old 

mallard duck (Anas platyrhynchos; MRID 48800301 in review) was assessed over 22 weeks. 

Flumetralin was administered to the birds in the diet at mean-measured concentrations were 

<LOQ (<100, control), 243, 493, and 971 mg ai/kg diet. No mortalities that were related to the 

treatment were observed in the control or any of the treatment groups during the 22-week study. 

No treatment-related effects were observed for feed consumption or changes in adult male body 

weight. Adult female body weight gain was statistically reduced at the mean-measured 493 and 

971 mg ai/kg diet treatment groups relative to the negative control. Slight dose-dependent and 

statistically-significant reductions were observed in hatchling weight and 14-day survivor 

weights at the 493 and 971 mg ai/kg diet treatment groups, relative to the negative control. The 

resulting NOAEC is 243 mg ai/kg diet.

4.3. Ecological Incidents

The ecological incident information system (EIIS) is an OPP database that houses ecological 

incidents that have been reported to the Agency. When available, EIIS includes date and 

location of an incident, type and magnitude of effects observed in various species, use(s) of 

pesticides known or suspected of contributing to the incident, and results of any chemical residue 

analysis or other analyses conducted during incident investigation. EIIS incidents are 

categorized according to the certainty that the incident resulted from pesticide exposure. The 

Avian Monitoring System (AIMS) is a database administered by the American Bird Conservancy 

that contains publicly available data on reported avian incidents involving pesticides. Many of 

the incidents listed in this database are also in the EIIS. 

As of July 2015, there is one reported incident for flumetralin in the EIIS database. The incident 

is for plant damage to almonds from direct application. The certainty is given as ‘probable’ and 
Page 15 of 27

the result of accidental misuse. Almonds are not a registered use for flumetralin, nor is tobacco a 

widely grown crop in Tehama, CA, where the damage occurred. 

As of July 2015, there are no incidents for flumetralin reported in the AIMS database. In 

addition to the incident reports available in EIIS, there were no aggregate incidents reported to 

the Agency.

5. Exposure Pathways of Concern

The environmental fate and toxicity profile for flumetralin suggests that direct spray, spray drift,

and runoff represent the likely exposure pathways for terrestrial and aquatic non-target 

organisms. Animal drinking water and inhalation exposure pathways were also screened using 

the SIP (Screening Imbibition Program) and STIR (Screening Tool for Inhalation Risk) 

screening methods.

6. Analysis Plan

6.1. Stressors of Concern

Parent flumetralin is considered as the sole stressor of concern. The major transformation 

product, a reduced analog of the parent, found in the anaerobic soil metabolism study is not 

expected to affect the aquatic EECs or affect terrestrial organisms.

6.2. Measures of Exposure 

EFED used standard available models to evaluate potential exposures to not previously assessed 

aquatic and terrestrial organisms and/or exposure routes as described at 

http://www.epa.gov/pesticides/science/models_db.htm.

Aquatic Exposure Assessment

EFED updated the aquatic EECs using the current surface water model, Surface Water 

Concentration Calculator (SWCC), to calculate the aquatic EECs for tobacco. EECs for the 

registered use on tobacco are based on 1st application at 1.2 lb a.i./A, applied by ground

equipment using the available North Carolina tobacco scenario. Results are shown in Table 5

(see model input and output in Appendix II). For comparison purposes, PRZM/EXAMS EECs 

in Table 5 were copied from EFED’s July 10, 2007 risk assessment to compare the old and new 

EECs for tobacco.

Aquatic EECs calculated using SWCC and PRZM/EXAMS are very similar, with only minor 

differences observed.
Page 16 of 27

Table 5. Comparison of Aquatic Estimated Environmental Concentrations (μg/L) for 

Flumetralin.

Crop

(Model)

Peak

(μg/L)

21-day Avg

(μg/L)

60-day Avg

(μg/L)

Tobacco

(SWCC – NCtobacco scenario) 3.81 0.442 0.335

Tobacco

(PRZM/EXAMS, 2007; 

NCtobacco scenario)

2.27 0.46 0.33

Terrestrial Exposure Assessment

Terrestrial Vertebrates

Terrestrial wildlife exposure estimates are typically calculated for birds and mammals 

emphasizing dietary uptake of pesticide through residues on vegetative and insect forage items. 

Avian terrestrial EECs are considered representative of potential exposure for terrestrial-phase 

amphibians and reptiles as well. For exposure to terrestrial organisms, pesticide residues on food 

items are estimated, based on the assumption that organisms are exposed to a single pesticide 

residue in a given exposure scenario and obtain 100% of their diet from treated areas. Exposure 

was evaluated using EECs generated from a spreadsheet-based screening model (T-REX v.1.5.2) 

that calculates the food ingestion rates of birds and mammals and the dissipation of a chemical 

applied to foliar surfaces for single or multiple applications. The terrestrial food item residue 

estimates are based on the methods of Hoerger and Kenaga (1972) as modified by Fletcher et al.

(1994) and food ingestion rates are estimated using allometric equations (USEPA, 1993). When 

data on the field dissipation of a chemical are absent, as in this case, EFED assumes a 35-day 

foliar dissipation half-life. However, since only one application is allowed, the foliar dissipation 

half-life is not used in calculations for flumetralin. 

The Screening Tool for Inhalation Risk (STIR v1.0) was used to calculate an upper-bound estimate 

of wildlife inhalation exposure using flumetralin’s vapor pressure and molecular weight for vapor 

phase exposure as well as the maximum application rate and method of application for spray drift. 

STIR incorporates results from several toxicity studies including acute oral and inhalation rat 

toxicity endpoints (rat LD50 >5000 mg/kg-bw; rat inhalation LC50 >2.2 mg/L) as well as the most 

sensitive acute oral avian toxicity endpoint (bobwhite LD50 = 2150 mg/kg-bw). Based on the 

results of the STIR model, exposure through inhalation of spray drift or the vapor phase of 

flumetralin is not determined to be a potential pathway of concern for either avian or mammalian 

species on an acute exposure basis.

 

The Screening Imbibition Program (SIP v1.0) was used to calculate an upper-bound estimate of 

wildlife drinking water exposure using flumetralin’s solubility (i.e., 0.07 mg/L at 20oC), and 

compared to the most sensitive acute and chronic avian and mammalian toxicity endpoints. 

Results of the screen indicate drinking water exposure alone is not a concern for birds or mammals 

on either acute or chronic basis. 
Page 17 of 27

Terrestrial Plants

Exposure to upland and wetland plants is estimated using the TerrPlant (v1.2.2) screening model. 

TerrPlant estimates potential exposure from a single application using default assumptions for 

runoff and spray drift. No changes are made from the 2007 RED chapter.

6.4 Preliminary Risk Review

No changes to the risk conclusions found in the 2007 EFED RED chapter have resulted from this 

review except for the evaluation of risk from chronic exposure to avian species (and their 

surrogate taxa). In short, there are no acute or chronic risks identified for aquatic organisms, 

except for listed fish from acute exposure. Additionally, there remain no data for aquatic 

nonvascular plants with which to assess potential risk to these taxa, thus risk is presumed. 

For terrestrial animals, there are no risks identified for birds (and surrogates) and mammals from 

acute exposure, but data for passerines are outstanding. The risk to mammals from chronic 

exposure identified in the RED chapter remains, but RQs were recalculated with the current

version of T-REX. There is a marginal exceedance of the LOC for birds based on chronic 

exposure. For both birds and mammals, RQs are for foraging on the treated field. There is 

uncertainty regarding their likelihood of foraging directly on tobacco plants given the nicotine. 

While other on-field forage is likely to remain, the magnitude of the residues on such forage 

items may be less than the model indicates. 

The dataset is incomplete for flumetralin regarding effects to terrestrial invertebrates. There is 

no indication of risk based on the available acute contact honeybee study; however acute and 

chronic oral studies are required for both adult and larval honeybees 

(http://www2.epa.gov/sites/production/files/2014-

06/documents/pollinator_risk_assessment_guidance_06_19_14.pdf). 

As a plant growth regulator, flumetralin is expected to have impacts on terrestrial plants. The 

risk identified in the RED remains, with grass species seemingly more sensitive to flumetralin 

exposure than forbs. As reported in the RED (based on the most sensitive species), RQs for 

nonlisted species range from 0.62 to 22 and for listed species the RQs range from 1.3 to 27.

Flumetralin has a log Kow greater than five, which is often an indicator of potential for 

bioaccumulation or biomagnification. However, a run of the KABAM (v1.0) model in 2007, 

which explores the likelihood of food-chain effects based solely on chemical properties, suggests 

this route of exposure to not be of concern for flumetralin. Also, based on a new review of the 

existing BCF study (see Table 2), the whole-fish bioconcentration factor is 612X, which is 

below the factor typically associated with food-chain effects (generally >1000X).
Page 18 of 27

Mammals

Dose-based chronic RQs are as high as an 8-fold exceedance of the LOC (Table 6), and there are 

exceedances for both upper-bound and mean exposure estimates. There are no exceedances for 

dietary-based RQs. When assessing potential chronic risk to mammals, the dietary-based 

NOAEC is converted to a dose-based NOAEL which can be scaled to different mammalian size 

classes. The dose-based RQs are calculated using a body weight adjusted and consumptionweighted equivalent dose. The adjustments account for the fact that smaller-sized animals have 

to consume more food in terms of their body weight than larger animals and that there is 

differential sensitivity to chemicals based on body size. By expressing the Kenaga nomogramestimated residues in terms of daily equivalent dose, estimated environmental concentrations can 

then be compared to the dose-based NOAEC. Both sets of RQs are presented in Table 6.

Table 6. Upper-bound Mammalian Chronic Exposure RQs for Flumetralin.

Forage items

Dose-based Dietarybased

Size class

15g 35g 1000g

Short grass 8.3a 7.11 3.8 0.96

Tall grass 3.8 3.3 1.8 0.44

Broadleaf plants 4.69 4.0 2.15 0.54

Fruits/pods 0.52 0.44 0.24 0.06b

Arthropods 3.3 2.8 1.5 0.38

Seeds 0.12 0.10 0.05 xx

a

Bold indicates exceeds chronic risk LOC (RQ≥1.0). b

Dietary-based RQs include seeds here.

Birds (surrogate for reptiles and terrestrial-phase amphibians)

As noted previously, avian reproduction data unavailable at the time of the RED have 

subsequently been submitted. As a result, the previous assumption of risk to these taxa can be 

quantitatively investigated. Based on the upper-bound residues calculated in T-REX, there is a 

marginal exceedance of the LOC based on the most sensitive of the available data (mallard duck; 

Table 7). There are no exceedances based on the mean exposure values. 
Page 19 of 27

Table 7. Upper-bound Avian Chronic Exposure RQs for Flumetralin.

Forage items Dietary-based

Short grass 1.19

Tall grass 0.54

Broadleaf plants 0.67

Fruits/pods/seeds 0.07

Arthropods 0.46

a

Bold indicates exceeds chronic risk LOC (RQ≥1.0).

7. Federally Threatened and Endangered (Listed) Species Concerns

In November 2013, the EPA, along with the U.S. Fish & Wildlife Service (USFWS), the 

National Marine Fisheries Service (NMFS) (collectively, the Services), and the U.S. Department 

of Agriculture (USDA) released a summary of their joint Interim Approaches for assessing risks 

to listed species from pesticides. The Interim Approaches were developed jointly by the 

agencies in response to the National Academy of Sciences’ (NAS) recommendations and reflect 

a common approach to risk assessment shared by the agencies as a way of addressing scientific 

differences between the EPA and the Services. The NAS report outlines recommendations on 

specific scientific and technical issues related to the development of pesticide risk assessments 

that EPA and the Services must conduct in connection with their obligations under the

Endangered Species Act (ESA) and FIFRA. 

The joint Interim Approaches were released prior to a stakeholder workshop held on November 

15, 2013. In addition, the EPA presented the joint Interim Approaches at the December 2013 

Pesticide Program Dialogue Committee (PPDC) and State-FIFRA Issues Research and 

Evaluation Group (SFIREG) meetings, and held a stakeholder workshop in April 2014, allowing 

additional opportunities for stakeholders to comment on the Interim Approaches. As part of a 

phased, iterative process for developing the Interim Approaches, the agencies will also consider 

public comments on the Interim Approaches in connection with the development of upcoming 

Registration Review decisions. The details of the joint Interim Approaches are contained in the 

white paper “Interim Approaches for National-Level Pesticide Endangered Species Act 

Assessments Based on the Recommendations of the National Academy of Sciences April 2013 

Report,” dated November 1, 2013. 

Given that the agencies are continuing to develop and work toward implementation of the 

Interim Approaches to assess the potential risks of pesticides to listed species and their 

designated critical habitat, this preliminary risk assessment for flumetralin does not contain a 

complete ESA analysis that includes effects determinations for specific listed species or 

designated critical habitat. Although EPA has not yet completed effects determinations for 

specific species or habitats, for this preliminary assessment EPA conducted a brief screeninglevel assessment for all taxa of non-target wildlife and plants that assumes for the sake of the 

assessment that listed species and designated critical habitats may be present in the vicinity of 

the application of flumetralin. This screening level assessment will allow EPA to focus its future 
Page 20 of 27

evaluations on the types of species where the potential for effects exists once the scientific 

methods being developed by the agencies have been fully vetted. This screening-level risk 

assessment for flumetralin indicates potential risks of direct effects to listed birds, mammals, and 

terrestrial plants when used on tobacco. Listed species of birds, mammals, and terrestrial plants 

may also be affected through indirect effects because of the potential for direct effects on listed 

and non-listed species upon which such species may rely. Potential direct effects on listed birds, 

mammals, and terrestrial plants from the use of flumetralin may be associated with modification 

of Primary Constituent Elements (PCEs) of designated critical habitats, where such designations 

have been made. Once the agencies have fully developed and implemented the scientific 

methods necessary to complete risk assessments for endangered and threatened (listed) species 

and their designated critical habitats, these methods will be applied to subsequent analyses for 

flumetralin as part of completing this registration review. 

8. Endocrine Disruptor Screening Program (EDSP)

Flumetralin was not included in the first group of 67 chemicals issued an order to conduct Tier 1 

EDSP testing. For additional information on the EDSP, visit http://www.epa.gov/endo/.

9. Environmental Fate and Ecological Effects Data

9.1. Environmental Fate

Table 8 identifies environmental fate studies by MRID that offer data for each guideline 

requirement, as well as study classifications and whether or not further data are needed in order 

to support risk assessment.
Page 21 of 27

Table 8. Submitted Environmental Fate Data for Flumetralin

OCSPP 

Guideline

Data 

Requirement

Submitted 

Studies (MRID)

Study 

Classifications

Are data needed 

to conduct risk 

assessment?

Justification and 

Assumptions EPA will 

Make in Absence of Data

835.2120 Hydrolysis MRID 41761508 Acceptable No

835.2240 Aqueous 

photolysis

Acc # 246683a

MRID 41761509

MRID 41761510

Not acceptable

Not acceptable

Not acceptable

Yes In lieu of available data, 

conservative assumptions 

had to be made in order to 

conduct the modeling to

determine EECs. The 

submission of new data, if 

valid, would decrease the 

uncertainty in the aquatic 

exposure assessment by 

providing more accurate 

values for use in 

determining EECs.

835.2410 Soil photolysis MRID 42566201

Acc # 246683b

Not acceptable

Not acceptable

Yes Information from this 

study enables the 

Agency to determine 

the stability of the 

pesticide when exposed 

to sunlight and to 

predict the likelihood 

of the pesticide

persisting in the 

environment, the 

photoproducts that are 

likely to be produced, 

and their stability

when exposed to 

sunlight.

835.4100 Aerobic soil 

metabolism

MRID 42566201a Supplemental No

835.4200 Anaerobic soil 

metabolism

MRID 42566201b Supplemental No

835.4300 Aerobic aquatic 

metabolism

No Data 

submitted

Yes In lieu of available data, 

conservative assumptions 

had to be made in order to 

conduct the modeling to

determined EECs. The 

submission of new data, if 

valid, would decrease the 

uncertainty in the aquatic 

exposure assessment by 

providing more accurate 

values for use in 

determining EECs.
Page 22 of 27

Table 8. Submitted Environmental Fate Data for Flumetralin

OCSPP 

Guideline

Data 

Requirement

Submitted 

Studies (MRID)

Study 

Classifications

Are data needed 

to conduct risk 

assessment?

Justification and 

Assumptions EPA will 

Make in Absence of Data

835.4400 Anaerobic 

aquatic 

metabolism

No Data 

submitted

Yes In lieu of available data, 

conservative assumptions 

had to be made in order to 

conduct the modeling to

determine EECs. The 

submission of new data, if 

valid, would decrease the 

uncertainty in the aquatic 

exposure assessment by 

providing more accurate 

values for use in 

determining EECs.

835.1230

835.1240

Adsorption/ 

desorption and 

leaching

MRID 41761511

MRID 41761512

Supplemental

Supplemental

No

835.6100 Terrestrial field 

dissipation

MRID 43014002

MRID 43014003

Not acceptable Yes In lieu of available data, 

conservative assumptions 

had to be made in order to 

conduct the modeling to

determine EECs. 

Storage Stability 

Study (TFD)

No Data 

submitted

Yes

850.1730 Fish 

bioconcentration

MRID 43014004 Supplemental No A new study would not 

provide significantly 

different results for 

flumetralin BCF estimates

Environmental

Chemistry

Method: Water

850.6100

Analytical 

method in water

and independent 

laboratory 

validation

No Data 

submitted

Yes Enforcement analytical 

methods are being routinely 

requested in registration 

review for use by state lead 

agencies.

Environmental

Chemistry

Method: Soil

Analytical 

method in soil 

and independent 

laboratory 

validation

No Data 

submitted

Yes Enforcement analytical 

methods are being routinely 

requested in registration 

review for use by state lead 

agencies.

9.2. Effects

The available ecological effects studies are provided below, with MRIDs for each guideline 

requirement as well as study classifications. Rationale for additional data requested is presented 

below.

Flumetralin may cause exposure of pollinators visiting off-site plants that are contaminated by 

spray drift. Acceptable toxicity data to honey bee adults and larvae have not been submitted for 

flumetralin and these data are needed to fulfill EPA’s recent policy on pollinator protection. A 

tier I study on the toxicity of residues on foliage (OCSPP 850.3030) is not needed since results of 

the honey bee acute contact LD50 is >100 μg a.i./bee, well above the 11 μg a.i./bee trigger 
Page 23 of 27

criterion. Considering that flumetralin is used when most tobacco plants are in the elongated 

button to early flower stage, when topping typically occurs, preceding full bloom, exposure of 

pollinators visiting tobacco plants is likely minimal; however, other pollinator forage in treated 

areas is likely. Thus, the following six Tier I, II and III honey bee studies, yet to be submitted 

for flumetralin, are required: 

o Honeybee adult and larval acute oral toxicity study (following OECD 237, Tier I)

o Honeybee adult 10-day chronic oral (special study; Tier I)

o Honeybee larval repeated dose study (special study renamed as honeybee larval 

chronic oral toxicity study, Tier I) 

o Semi-field testing for pollinators (special study, Tier II). 

o Field testing for pollinators (OCSPP 850.3040, Tier III)

o Field trial of residues in pollen and nectar (special study, Tier III)

Note that it is possible to conduct the larval chronic oral study in such a way as to derive both 

an LD50 (acute endpoint of interest) and a NOAEC (chronic endpoint of interest) from a 

single study. If the chronic larval toxicity study is conducted in such a way that it derives 

both an LD50 and NOAEC, then a separate acute larval toxicity study is not needed. For 

pollinator studies without finalized OECD guidelines, protocols should be submitted for EPA 

review and comment prior to study initiation.

Although requested, the need for higher Tier semi-field and full field pollinator studies for 

flumetralin will be determined after review of these Tier I studies.

Acceptable acute avian acute oral toxicity data were not submitted for a passerine species 

exposed to flumetralin, which is now required under the 40 CFR Part 158 data requirements. 

Though the available studies indicate suggest flumetralin has low acute toxicity to bird species, it 

is uncertain whether passerines may be more or less sensitive to this chemical as a result of their 

higher metabolic rate and differing metabolic pathways. An avian oral toxicity study is needed 

for a passerine species. 

Additional data needs are for aquatic nonvascular plants. While data on green algae are used 

provisionally in this assessment, the underlying study has not been reviewed by EPA. Further, 

three other taxa of aquatic nonvascular species are necessary to complete a risk assessment

(850.4500; 850.4550). A review of the Footprint database also suggests there are other 

invertebrate data available; submission of those studies would help develop a more complete 

understanding of the effects of flumetralin.

Available Ecotoxicity Studies

MRID/Classification Citation Reference

00094016/Acceptable Fletcher, D.W. (1981) Report to Ciba Geigy Corporation, Agricul- tural Division: Acute 

Oral Toxicity Study with CGA-41065, Tech- nical in Bobwhite Quail: BLAL No. 81QD3. 

(Unpublished study received Jan 28, 1982 under 100-EX-72; prepared by Bio-Life 

Associates, Ltd., submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:246683-C) 
Page 24 of 27

00094017/Acceptable Fletcher, D.W. (1981) Report to Ciba Geigy Corporation, Agricul- tural Division: Acute 

Oral Toxicity Study with CGA-41065, Tech- nical in Mallard Ducks: BLAL No. 81DD1. 

(Unpublished study received Jan 28, 1982 under 100-EX-72; prepared by Bio-Life 

Associates, Ltd., submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:246683-D) 

71-2 Avian Dietary Toxicity

MRID Citation Reference

00094018/Acceptable Fletcher, D.W. (1981) Report to Ciba Geigy Corporation, Agricul- tural Division: 8-day 

Dietary LC50 Study with CGA-41065 Tech- nical in Bobwhite Quail: BLAL No. 81 QC 5. 

(Unpublished study received Jan 28, 1982 under 100-EX-72; prepared by Bio-Life 

Associates, Ltd. and Ralston Purina Co., submitted by Ciba-Geigy Corp., Greensboro, 

N.C.; CDL:246683-E) 

00094019/Acceptable Fletcher, D.W. (1981) Report to Ciba Geigy Corporation, Agricul- tural Division: 8-day 

Dietary LC50 Study with CGA-41065 Tech- nical in Mallard Ducklings: BLAL No. 

81DC5. (Unpublished study received Jan 28, 1982 under 100-EX-72; prepared by Bio-Life 

Associates, Ltd. and Ralston Purina Co., submitted by Ciba-Geigy Corp., Greensboro, 

N.C.; CDL:246683-F) 

72-1 Acute Toxicity to Freshwater Fish

MRID Citation Reference

116602/Supplemental Griffen, J.; McAllister, W.; Cranor, W.; et al. (1982) Acute Tox- icity of CGA-41065 to 

Bluegill Sunfish (Lepomis macrochirus): Static Acute Bioassay Report #28783. 

(Unpublished study re- ceived Oct 4, 1982 under 100-640; prepared by Analytical BioChemistry Laboratories, Inc., submitted by Ciba-Geigy Corp., Greensboro, NC; 

CDL:248447-B) 

00116603/Supplemental Griffen, J.; McAllister, W.; Cranor, W.; et al. (1982) Acute Tox- icity of CGA-41065 to 

Rainbow Trout (Salmo gairdneri): Static Acute Bioassay Report #28784. (Unpublished 

study received Oct 4, 1982 under 100-640; prepared by Analytical Bio-Chemistry 

Laboratories, Inc., submitted by Ciba-Geigy Corp., Greensboro, NC; CDL:248447-C) 

43456601/Acceptable Bettencourt, M. (1994) CGA-41065: Acute Toxicity to Bluegill Sunfish (Lepomis 

macrochirus) Under Flow-Through Conditions: Final Report: Lab Project Number: 

94/8/5428: 1781/0394/6438/ 105. Unpublished study prepared by Springborn Labs, Inc. 

75 p. 

72-2 Acute Toxicity to Freshwater Invertebrates

MRID Citation Reference

00116599/Supplemental Forbis, A.; Boudreau, P.; Franklin, L.; et al. (1982) Acute Tox- icity of CGA-41065 to 

Daphnia magna: Static Acute Bioassay Re- port #28785. (Unpublished study received 

Oct 4, 1982 under 100- 640; prepared by Analytical Bio-chemistry Laboratories, Inc., 

submitted by Ciba-Geigy Corp., Greensboro, NC; CDL:248446-A) 
Page 25 of 27

43456602/Acceptable Putt, A. (1994) CGA-41065: Acute Toxicity to Daphnids (Daphnia magna) Under FlowThrough Conditions: Lab Project Number: 94/9/5487. Unpublished study prepared by 

Springborn Labs, Inc. 78 p. 

72-3 Acute Toxicity to Estuarine/Marine Organisms

MRID Citation Reference

43456603/Acceptable Bettencourt, M. (1994) CGA-41065: Acute Toxicity to Sheepshead Minnow (Cyprinodon 

variegatus) Under Flow-Through Conditions: Final Report: Lab Project Number: 

94/9/5479: 1781/0394/6435/ 505. Unpublished study prepared by Springborn Labs, Inc. 74 

p. 

43456604/Acceptable Dionne, E. (1994) CGA-41065: Acute Toxicity to Eastern Oyster (Crassostrea virginica) 

under Flow-Through Conditions: Final Report: Lab Project Number: 94/7/5391: 

1781/0394/6436/504. Unpublished study prepared by Springborn Labs, Inc. 81 p. 

43456605/Acceptable Bettencourt, M. (1994) CGA-41065: Acute Toxicity to Mysids (Mysidopsis bahia) Under 

Flow-Through Conditions: Final Report: Lab Project Number: 94/10/5493: 

1781/0394/6434/515. Unpublished study prepared by Springborn Labs, Inc. 79 p. 

72-4 Fish Early Life Stage/Aquatic Invertebrate Life Cycle Study

MRID Citation Reference

00116598/Acceptable Forbis, A.; Franklin, L.; Boudreau, P.; et al. (1982) Early Life Stage Toxicity of CGA41065 to Fathead Minnows (Pimephales promelas, Rafinesque) in a Flow-through System: 

Report #29218. Final rept. (Unpublished study received Oct 4, 1982 under 100- 640; 

prepared by Analytical Bio-Chemistry Laboratories, Inc., submitted by Ciba-Geigy Corp., 

Greensboro, NC; CDL:248445-B) 

00116600/Acceptable Forbis, A.; Franklin, L.; Boudreau, P.; et al. (1982) Chronic Toxicity of CGA-41065 to 

Daphnia Magna in a Flow-through System: Report #28969. Final rept. Unpublished study 

received Oct 4, 1982 under 100- 640; prepared by Analytical Bio-Chemistry Laboratories, 

Inc., submitted by Ciba-Geigy Corp.

122-2 Aquatic plant growth

MRID Citation Reference

43456606/Acceptable Hoberg, J. (1994) CGA-41065: Toxicity to Duckweed (Lemna gibba): Final Report: Lab 

Project Number: 94/8/5425: 1781/0394/ 6437/410. Unpublished study prepared by 

Springborn Labs, Inc. 72 p. 

123-1 Seed germination/seedling emergence and vegetative vigor

MRID Citation Reference
Page 26 of 27

41847001/Acceptable Chetram, R. (1991) Tier 2 Seedling Emergence Nontarget Phytotoxi- city Study Using 

Prime + (CGA-41065): Lab Project Nos. LR90-431; TX-90-0158. Unpublished study 

prepared by Pan-Agricultural Laboratories, Inc. 126 p. 

41847002/Acceptable Chetram, R. (1991) Tier 2 Vegetative Vigor Nontarget Phytotoxi- city Study Using Prime 

+ (CGA-41065): Lab Project Nos. LR90-429; TX-90-0158. Unpublished study prepared 

by Pan-Agricultural Laboratories, Inc. 150 p. 

123-2 Aquatic plant growth

MRID Citation Reference

43456606/Acceptable Hoberg, J. (1994) CGA-41065: Toxicity to Duckweed (Lemna gibba): Final Report: Lab 

Project Number: 94/8/5425: 1781/0394/ 6437/410. Unpublished study prepared by 

Springborn Labs, Inc. 72 p. 

141-1 Honey bee acute contact

MRID Citation Reference

41761507/Acceptable Kirkland, R. (1991) CGA-41065 Technical: Acute Contact Toxicity of CGA-41065 to 

Honey Bees (Apis Mellifera L.): Lab Project Number: CAR 198-90. Unpublished study 

prepared by California Agricultu- ral Research, Inc. 32 p. 
Page 27 of 27

Appendix I. SWCC Model output

Table 1. Estimated Environmental Concentrations (ppb) for Flumetralin.

Peak (1-in-10 yr) 3.81

4-day Avg (1-in-10 yr) 0.965

21-day Avg (1-in-10 yr) 0.442

60-day Avg (1-in-10 yr) 0.335

365-day Avg (1-in-10 yr) 0.267

Entire Simulation Mean 0.228

Table 2. Summary of Model Inputs for Flumetralin.

Scenario NCtobaccoSTD

Cropped Area Fraction 1

Koc (ml/g) 71649

Water Half-Life (days) @ 25 °C 7320

Benthic Half-Life (days) @ 25 °C 252

Photolysis Half-Life (days) @ 40 

°Lat

0

Hydrolysis Half-Life (days) 0

Soil Half-Life (days) @ 22 °C 3660

Foliar Half-Life (days) 35

Molecular Wt 421.7

Vapor Pressure (torr) 2.4E-7

Solubility (mg/l) 0.7

Table 3. Application Schedule for Flumetralin.

Date (Mon/Day) Type Amount (kg/ha) Eff. Drift

6/27 Ground 1.34 0.99 0.062