2 

Key Uncertainties and Data Gaps 

Major findings include the following data needs and the uncertainties described below: 

 Anaerobic aquatic metabolism (835.4400): 

An anaerobic aquatic metabolism study is not available. A guideline compliant study is 

needed because the data is of core input to EFED’s exposure models in risk assessment. 

 Adsorption/Desorption (835.1230): 

Most of the previously submitted studies were unacceptable due the use of sterilized 

soils. Data is available for a study on fluazifop-p-acid but the study is deemed 

supplemental due to insufficient mass balance, use of only foreign soils, and absence of 

soils with less than 1% organic matter. A new study is needed for fluazifop-p-butyl and 

its degradates. 

 Avian Reproduction (850.2300): 

Avian Reproduction studies were submitted and reviewed in 1982. These studies used 

technical fluazifop-butyl, which is now cancelled. There were a number of problems 

with these studies which included deaths in the controls and maximum concentrations (50 

ppm in both studies) were less than expected maximum field residue exposure levels (in 

the current case 1.125 lbs a.i./A x 240 ppm = 270 ppm). The SOP recommends testing at 

concentrations equal to expected field residue levels. Testing should be done with 

fluazifop-p acid, since fluazifop-P-butyl is rapidly degraded in soil to fluazifop-p acid, 

which is much more stable in soil and water environments than the parent. 

 Honeybee toxicity (non-guideline): 

In keeping with the Agency’s proposed new paradigm for determining potential adverse 

effects to insect pollinators from conventional pesticides (USEPA 2012), additional 

studies are being requested in addition to the acute contact study already submitted. Even 

though contact to fluazifop-p-butyl is slightly toxic to honeybees, an adult acute oral 

toxicity study (following OECD 213) and a larval toxicity study (following OECD 237) 

are necessary to evaluate the potential for fluazifop-p-butyl and/or acid to adversely 

affect bees and other pollinators through other routes of exposure. In addition, adult and 

larval chronic studies are being requested. Several of the treated crop areas may be 

considered attractive to honey bees and this is a systemic chemical that is transported 

throughout the plant. Thus, residues may be available to pollinators via pollen and/or 

nectar. 

 Terrestrial Plant Toxicity (850.4100 and 850.4150): 

Fluazifop-p-butyl is a post-emergent systemic aryloxyphenoxypropionic herbicide to 

control perennial and annual grass weeds. In general, it has little effect on broad-leaved 

plants (dicots) (Ware and Whitacre 2004). Fluazifop-p-butyl is registered to control 

monocot plant species and there are reported incidents in EFED’s Ecological Incident 

Information System (EIIS) database where crop damage was reported on corn, which is a 

monocot species. There are no guideline toxicity data to assess risks to terrestrial plants. 

Tier I seedling emergence and vegetative vigor studies are needed. Testing should be 

done with fluazifop-p-butyl which degrades rapidly in soil into fluazifop-p acid, both 

toxic components of herbicidal activity. Two studies (vegetative vigor and seedling 

emergence) have been recently submitted and are in review. If these studies are found to 

be scientifically sound, then new studies will not be needed. 
3 

 Aquatic Plant Toxicity (850.4400, 850.4500 & 850.4550): 

Aquatic plant testing is required for any herbicide that has outdoor non-residential 

terrestrial uses that may move off-site by runoff, by drift, or that is applied directly to 

water. Two aquatic plant studies have been submitted and one was deemed invalid. The 

second study used metabolite X and is currently in review. Tier II testing should be done 

using fluazifop-p acid. 

 Estuarine/Marine Fish (850.1350 and 850.1400): 

No data have been submitted regarding chronic toxicity to estuarine/marine fish or 

invertebrates. Fluazifop is highly acutely toxic to freshwater fish and invertebrates. In 

addition, use on golf courses can occur near estuarine areas. Since fluazifop-p-butyl 

breaks down very quickly, testing should be done using the acid for chronic studies. 

All degradation and analytical method studies should state the enantiomeric purity of the 

chemical used in testing and the enantiomer ratios in the residue characterizations. 

 
4 

Table	of	Contents	

1. Introduction ............................................................................................................................. 5

2. Use Characterization ............................................................................................................... 5

3. Conclusions from Previous Risk Assessments ..................................................................... 10

3.1. Ecological Risk Assessments ......................................................................................... 10

3.2. Drinking Water Exposure Assessments ......................................................................... 10

3.3. Clean Water Act Programs ............................................................................................. 10

3.3.1. Aquatic Life Criteria and Aquatic Life Benchmarks .................................................. 10

3.3.2. Impaired Water Bodies ............................................................................................... 11

4. Environmental Fate and Transport........................................................................................ 11

4.1. Chemical Identity and Mode of Action .......................................................................... 11

4.2. Enantiomer Considerations for Fluazifop-p-butyl ......................................................... 12

4.3. Physico-chemical Properties of Fluazifop-p-butyl and Related Compounds ................ 13 

 4.4. Environmental Fate and Transport...............................................................16 

4.5. Transformation Products ................................................................................................. 19

5. Receptors ............................................................................................................................... 29

5.1. Effects to Aquatic Organisms ........................................................................................ 30

5.2. Effects to Terrestrial Organisms .................................................................................... 31

5.3. Ecological Incidents ....................................................................................................... 32

6. Exposure Pathways of Concern ............................................................................................ 33

7. Analysis Plan ........................................................................................................................ 34

7.1. Stressors of Concern....................................................................................................... 34

7.2. Measures of Exposure .................................................................................................... 34

7.3. Measures of Effect ......................................................................................................... 34

8. Endangered Species Assessments ......................................................................................... 35

9. Endocrine Disruptor Screening Program .............................................................................. 35

10.    Preliminary Identification of Data Gaps ............................................................................... 37

10.1.   Environmental Fate ........................................................................................................ 37

10.2.   Ecological Effects ........................................................................................................... 44

11. References .......................................................................................................................... 47

APPENDIX A: Eco and Fate Bibliography for Fluazifop ............................................................ 51

APPENDIX B: ECOLOGICAL TOXICITY DATA ................................................................... 65

APPENDIX C: Example of SIP INPUT and OUTPUT ............................................................... 75

APPENDIX D: STIR inputs and outputs ...................................................................................... 77
Page 5 of 78 

1. Introduction 

EFED evaluated the most recent ecological risk assessments for fluazifop-p-butyl 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. Recent risk 

assessments include new use assessments in 2008 (peanuts and dry beans) and 2010 (bananas, 

plantains, citrus, grapes and sugarbeets). In addition, EFED considered the latest Agency 

science policies and risk assessment methodologies. The structure of fluazifop-p-butyl, as well 

as the chemical names and other identifiers, can be found in the environmental fate section. 

Butyl (R)-2-{4-[5-(trifluoromethyl)-2-pyridyloxy]phenoxy}propionate (common name fluazifopp-butyl) is an aryloxphenoxypropionic (formerly oxyphenoxy acid esters) class herbicide (Wood 

2007; Ware and Whitacre 2007). The mode of action is via inhibition of CoA carboxylase, 

resulting in decreased lipid synthesis, especially at sites of active growth resulting in the 

disruption of cell walls (Tu et al. 2001). It is selective, post-emergent, and systemic and is used 

to control perennial and annual grass weeds (Wood 2007). In general, it has little effect on 

broad-leaved plants (dicots) (Ware and Whitacre 2004). It is rapidly absorbed through leaf 

surfaces and hydrolyzes in the plant to fluazifop-acid, and then it is transported in phloem and 

accumulates in the meristems (Tu et al. 2001). It may be applied as a ground spray, aerial spray, 

and in irrigation systems. Fluazifop-P-butyl is rapidly (less than one day) degraded in soil to 

fluazifop acid, which is much more stable in soil and water environments than the parent. Fluazifop 

and its acid degradate exist as stereoisomers. In this assessment, fluazifop-p-butyl and fluazifop-pacid refer to the enriched (R) isomer, which is the more herbicidally active form. Fluazifop butyl and 

fluazifop acid (without the “p” designation) refer to the racemic mixture (50% R,S). Current 

products contain the R-enriched isomer, fluazifop-p-butyl. 

2. Use Characterization 

Uses of fluazifop-p-butyl include terrestrial agricultural food uses, nonfood uses such as fallow 

land and noncrop areas, and residential/commercial uses such as turf, ornamentals, and in 

landscapes. 

 

 
Page 6 of 78 

 

 

Table 1. Maximum application rates for current uses of Fluazifop-p-butyl 

Site

Single       

App Rate  

(lb ai / A)

Max

#Apps/CC

Max

Dose/CC      

(lb ai /

A/CC)  

Max

#Apps/Year

Max

Dose/Year

(lb ai /

A/Yr)

MRI

(days) Reg Numbers

Soybeans 0.375 1 0.375 1 0.47 14 100‐1059

Cotton 0.375 2 0.750 2 0.750 14 100‐1059

Roadside Rights‐of‐

way

0.375 1 0.375 1 0.375 14 100‐1059

Apricots, Cherries,

Nectarines, Peaches,

Plums, Prunes

0.375 3 1.125 3 1.125 14 100‐1070

Asparagus 0.375 2 0.750 2 0.750 14 100‐1070

Asparagus 0.188 2 0.375 2 0.375 21 100‐1070

Bananas and Plantains 0.375 3 1.125 3 1.125 30 100‐1070

Carrots (including seed

carrots), dry Bulb

Onions, Garlic

0.375 2 0.750 2 0.750 14 100‐1070

Citrus Fruits 0.375 3 1.125 3 1.125 21 100‐1070

Coffee 0.375 2 0.750 2 0.750 14 100‐1070

Cotton 0.375 2 0.750 2 0.750 14    

Dry Beans (except

cowpeas) 0.375 2 0.750 2 0.750 14 100‐1070

Grapes 0.375 3 1.125 3 1.125 14 100‐1070

Macadamia Nuts 0.375 2 0.750 2 0.750 14 100‐1070

Peanuts 0.375 2 0.750 2 0.750 14 100‐1070

Pecans 0.375 3 1.125 3 1.125 14 100‐1070

Rhubarb 0.375 2 0.563 2 0.563 14 100‐1070

Soybeans 0.375 2 0.47 2 0.47 14 100‐1070

Sugar beets 0.375 2 0.750 2 0.750 14 100‐1070

Sweet potatoes, Yams 0.375 2 0.750 2 0.750 14 100‐1070

Tabasco Peppers 0.375 2 0.750 2 0.750 14 100‐1070

Non‐bearing groves,

Orchards, Vineyards,

Tree Farms*

0.375 3 1.125 3 1.125 14 100‐1070

Non‐food use ‐ 

Agricultural Fallow

Land and Non‐crop

areas

0.375 3 1.125 3 1.125 14 100‐1070

Landscaped areas,

roadsides, field grown

ornamentals,

greenhouses,

nurseries, flower beds,

and all other non‐turf

areas

0.375 2 0.75 2 0.75 14 100‐1084
Page 7 of 78 

Site

Single       

App Rate  

(lb ai / A)

Max

#Apps/CC

Max

Dose/CC     

(lb ai /

A/CC)  

Max

#Apps/Year

Max

Dose/Year

(lb ai /

A/Yr)

MRI

(days) Reg Numbers

Zoysia, Tall Fescue 0.094 not specified

not

addressed

on label

not

specified

not

specified 28 100‐1084

Alfalfa Grown for

Seed

0.125‐

0.188 2 0.313 2 0.313 14 OR‐040006

(100‐1070)

Alfalfa Grown for

Seed and Clover

Grown for Seed

0.19 2 0.313 2 0.313 14 NV‐040006

(100‐1070)

Alfalfa Grown for

Seed

0.125‐

0.188 2 0.313 2 0.313 14

MT‐030010

(100‐1070)

WA‐040007

(100‐1070)

WY‐03‐0006

(100‐1070)

Alfalfa Grown for

Seed and Clover

Grown for Seed

ID‐950006

(100‐1070)

Fine Fescue Grasses

(chewings, hard,

and creeping red

varieties) grown for

Seed

0.25 4 1 4 1

before

regrowth

exceeds

10 in.

ID‐040003

(100‐1070)

Fine Fescues grown

for Seed 0.25 4 1.00 4 1.00

before

regrowth

exceeds

10 in.

OR‐950013

(100‐1070)

Fine Fescue Grasses

(chewings, hard,

and creeping red

varieties) grown for

Seed

0.25 4 1.00 4 1.00

before

regrowth

exceeds

10 in.

WA‐040024

(100‐1070)

Guayule (non‐food

use) 0.375 3 1.125 3 1.125 28 AZ‐070006(100‐1070)

Cabbage, Chinese

cabbage, Kale,

Spinach, Swiss

Chard, Table Beet

Grown for Seed

0.25 2 0.50 2 0.50 None

Listed

WA‐040006

(100‐1070)

Wildlands 0.375 3 1.125 3 1.125 14 CA‐110010

(100‐1070)

Prairie and Riparian

Conservation and

Restoration Areas

0.375 3 1.125 3 1.125 14 OR‐120016

(100‐1070)

Daffodils 0.25 1 0.25 1 0.25 NA WA‐130007

(100‐1084)

 
Page 8 of 78 

Restriction Codes

1 ‐ Do not graze animals in treated areas 

2 ‐ All states except California and Arizona 

3 ‐ California only    

4 ‐ Includes Calamondin, Citrus citron, Citrus hybrids, Grapefruit, Kumquat, Lemon, Lime, Mandarin (Tangerine), Orange (all),

Pummelo, and Satsuma

5 ‐ Hawaii only 

6 ‐ Do not apply to cotton after boll set    

7 ‐ Do not graze or harvest for forage or hay 

8 ‐ Do not apply to cowpeas    

9 ‐ Do not graze animals in treated areas or feed cover crop of treated macadamia groves to livestock   

10 ‐ Do not feed green immature growing plants to livestock or harvest for livestock feed   

11 ‐ Maryland and New Jersey only    

12 ‐ Do not exceed 1.2 lbs. (76 fl oz.) per acre over a two year period 

13 ‐ Do not apply more than 24 fl. oz. per acre pre bloom (up to V5). Do not apply more than 6 fl oz. per acre from bloom

through post bloom (R1 or later).

14 ‐ Louisiana only    

15 ‐ Apply to actively growing grasses before they exceed the specified growth stages.   

Spray to obtain thorough coverage, but not to runoff. Repeat treatments may be necessary.   

Apply when first grass species in a mixed grasss weed population reaches the specified growth stage for treatment

Do not apply to grasses which are stressed due to moisture, temperature, low soil fertility, mechanical or chemical injury.

Do not apply to grasses which have tillered, formed seed heads, or exceeded listed growth stages.   

When treating nonbearing trees and vines, avoid contact of spray with foliage by using directed sprays.

Do not apply to trees, vines, or other listed crops that will be harvested for food/feed within one year after application

Do not apply to asparagus from which the spears will be harvested within 1 year of treatment.   

Do not graze or harvest Florigraze rhizoma peanuts for 1 year after treatment.   

Do not plant rotational grass crops such as corn, sorghum and cereals within 60 days after the last application.

Do not apply a total of more than 72 fluid ounces per acre per season. 

16 ‐ Spray to obtain thorough coverage of grass foliage, but not to runoff. Repeat treatments may be necessary.

Apply when first grass species in a mixed grasss weed population reaches the specified growth stage for treatment

Do not apply to grasses which are stressed due to moisture, temperature, low soil fertility, mechanical or chemical injury.

Do not apply to grasses which have tillered, formed seed heads, or exceeded listed growth stages.   

Do not apply a total of more than 72 fluid ounces per acre per season. 

17 ‐ Do not graze animals in treated areas or feed treated plants.    

18 ‐ No portion of this seed crop may be used for food or feed for 1 year after the last application.   

19 ‐ No portion of the treated field, including seed, seed screenings, hay, forage, or stubble, may be used for human or animal

feed.

20 ‐ No portion of the alfalfa seed plant, including but not limited to green chop, hay, pellets, meal, whole

seed, cracked seed, roots, bulbs, leaves and seed screenings may be used or distributed for food or feed

purposes.

21 ‐ Do not plant rotational grass crops such as corn, sorghum and cereals within 60 days after last application.

22 ‐ Treated fields may not be grazed or harvested for forage until after harvesting grass seed crop.   

23 ‐ Do not graze livestock in treated fields within 1 year (365 days) of application.   

24 ‐ Do not allow livestock to graze treated fields. Do not use treated crops for livestock feed. Crop residues are not to be fed

to livestock or baled for such use

25 ‐ No portion of the cabbage, chinese cabbage, kale, spinach, swiss chard, and table beet seed plant may be used or

distributed for food or feed purposes.

 
Page 9 of 78 

 Figure 1. Agricultural Usage of fluazifop-p-butyl in 2011 (USGS, 2014). (From the Pesticide National Synthesis Project available at: 

http://water.usgs.gov/nawqa/pnsp/usage/maps/show_map.php?year=2011&map=FLUAZIFOP&hilo=L&disp=Fluazifop) 
Page 10 of 78 

3. Conclusions from Previous Risk Assessments 

3.1. Ecological Risk Assessments 

The Agency has previously conducted ecological risk assessments on fluazifop that serve as a 

basis for this problem formulation. The primary risks described in previous assessments have 

been risks to terrestrial plants and aquatic monocots, which is expected given that fluazifop is an 

herbicide. Risks of concern have also been identified to mammals and saltwater invertebrates 

from chronic exposure. 

3.2 Drinking Water Exposure Assessments 

In 2010, a drinking water exposure assessment for fluazifop-p-butyl was conducted to support 

the human health risk assessment for the Section 3 new use registration on bananas, plantains, 

citrus, grapes, and sugar beets pre-bloom and post-bloom (Strader 2009). It was conducted on 

fluazifop-p-butyl residues of concern which is the parent compound and its acid. For aerial 

applications the highest surface water EECs reported for peak, 1-in-10 peak, 1-in-10 year annual 

mean, and the 30 year mean as estimated by PRZM/EXAMS for all crop use scenarios were 33.4 

ppb, 6.6 ppb, and 4.4 ppb, respectively. For ground applications the highest EECs for 1-in-10 

peak, 1-in-10 year annual mean, and the 30 year mean were 32.1 ppb, 5.8 ppb, and 3.1 ppb, 

respectively. SCI-GROW estimated the concentration of fluazifop-acid in shallow ground water 

sources to be 1.56 ppb1

. An updated drinking water assessment will be conducted for 

registration review, if needed. 

3.3 Clean Water Act Programs 

3.1.1. Aquatic Life Criteria and Aquatic Life Benchmarks 

The Clean Water Act requires the Agency to publish water quality criteria that accurately reflect 

the latest scientific knowledge on the kind and extent of all identifiable effects on health and 

welfare that might be expected from the presence of pollutants in any body of water, including 

ground water. While these recommended criteria do not, in themselves, impose any 

requirements, states and authorized tribes can use them to develop water quality standards. An 

Aquatic Life Ambient Water Quality Criteria document has not been published for fluazifop-pbutyl (see url: http://www.epa.gov/waterscience/criteria/). 

The Office of Pesticide Programs (OPP) publishes aquatic life benchmarks for freshwater species 

based on toxicity values for the most sensitive species from the most recent risk assessments. 

However, aquatic life benchmarks have not been published for fluazifop-p-butyl or its acid (see 

url: http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm#benchmarks). 

 

1

 Memorandum from Wm. J. Shaughnessy, EFED ERBII to Joanne Miller, Registration Division, subj: Drinking 

Water Assessment for the Section 3 Registration of Fluazifop-p-butyl for New Use on Bananas, Plantains, Citrus, 

Grapes and Sugar Beets. 
Page 11 of 78 

3.1.2. Impaired Water Bodies 

Fluazifop-p-butyl is not identified as a cause of impairment for any water bodies listed as 

impaired under section 303(d) of the Clean Water Act, based on information provided at 

http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=88

5. 

No Total Maximum Daily Load (TMDL) criteria have been developed for fluazifop-p-butyl, 

based on information provided at 

http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id

=885&p_pollutant_group_name=PESTICIDES. More information on impaired water bodies and 

TMDLs can be found at http://www.epa.gov/owow/tmdl/. The Agency invites submission of 

water quality data for this pesticide. To the extent possible, data should conform to the quality 

standards in Appendix A of the OPP Standard Operating Procedure: Inclusion of Impaired 

Water Body and Other Water Quality Data in OPP’s Registration Review Risk Assessment and 

Management Process (see: 

http://www.epa.gov/oppsrrd1/registration_review/water_quality_sop.htm), in order to ensure 

they can be used quantitatively or qualitatively in pesticide risk assessments. 

4. Environmental Fate and Transport 

 4.1. Chemical Identity and Mode of Action 

Fluazifop-p-butyl, [butyl (R)-2-{4-[5-(trifluoromethyl)-2-pyridyloxy]phenoxy}propionate, (CAS 

No. 79241-46-6; PC code 122809)] is a R-isomer chiral molecule from the racemic mixture 

(50:50 R & S form) of fluazifop-butyl. It is relatively non-persistent and non-mobile in the 

environment as it rapidly (T1/2 = 0 - <2 d) degrades in aerobic soil (both laboratory soil and field 

dissipation studies) to fluazifop-acids (may be present in the R or S form or as a mixture of the 

enantiomers). Fluazifop-p-butyl is not likely to volatize (1.7 x 10-6 torr) at environmental 

temperatures, degrades slowly via soil photolysis (T1/2 = 195 d), and is slightly soluble (1.0 mg/L) 

with higher affinity for organics than for water. The acids are much more persistent in soil and 

water environments than the parent. Thus, studies on the fluazifop-acids were used to fulfill some of 

the data requirements of the parent compound. Both enantiomers are currently reviewed together 

because there is no evidence so far that indicate that the environmental fate would be different for 

the different enantiomers. Other major degradates of fluazifop-p-butyl are 2-hydroxy-5-

trifluoromethylpyridine (degradate X), 4-(5-Trifluoromethylpyridin-2-yloxy) phenol (degradate 

IV), SYN546933, and R201189. There are currently no data for fluazifop-p-butyl regarding 

anaerobic aquatic metabolism and no acceptable batch equilibrium study. However, leaching and 

field dissipation studies showed that fluazifop-acids, which are present in the anionic form at 

most environmental pHs, are expected to be highly mobile and have the potential to leach into 

groundwater. 

 

Table 3. Chemical identification for the active ingredient fluazifop-p-butyl 

Common Name: Fluazifop-p-butyl 

Pesticide Class: aryloxphenoxypropionic herbicide 

EPA PC Code: 122809 

IUPAC Name: butyl (R)-2-{4-[5-(trifluoromethyl)-2-pyridyloxy]phenoxy}propionate 
Page 12 of 78 

CAS Name: butyl (2R)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoate 

CAS No: 79241-46-6 

Synonyms: fluazifop-P butyl ester; fluazifop-r-butyl; Fusilade 2000; Fusilade DX; Fusilade S; Fusilade 

super; PP 005; Propanoic acid, 2-(4-((5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)-, butyl 

ester, (R)- 

SMILES Code: n1cc(C(F)(F)F)ccc1Oc2ccc(OC(C)C(=O)OCCCC)cc2 

Structure: 

 4.2. Enantiomer Considerations for Fluazifop-p-butyl 

A few different compounds are associated with the common name, fluazifop-butyl. Fluazifopbutyl is the racemic mixture (e.g., consists of equal amounts of the R and S enantiomers) of 

butyl-2-{4-[5-(trifluoromethyl)-2-pyridyloxy]phenoxy}propionate. Fluazifop-p-butyl (PC Code 

122809) is the R enantiomer and is more herbicidally active than the S enantiomer (Tu et al.

2001). Both degrade via microbial mediated hydrolysis in moist soil and sediments to the 

fluazifop-acid which can also exist in the R or S form (MRID 162455; 87493, 92067033, 87492, 

92067032, 46190602, 46190605). 

U.S.EPA2 formerly indicated that the data requirements for the two active ingredients should be 

considered separately. This approach is supported by reports that different enantiomers of the 

same chemical can have different biological activities, e.g., toxicities (Xu et al. 2008).3 In the 

same memo (1991), the environmental fate review indicated that data for fluazifop-butyl would 

be acceptable to fulfill the environmental fate requirements of fluazifop-p-butyl, unless evidence 

indicated that the environmental fate would be different for the different enantiomers. 

 

Enantiomers have been studied for fluazifop-butyl and related compounds in three British soils 

and in a mixed microbial population where conversion of the S acid to the R acid was reported 

(Bewick 1986). The R:S enantiomer ratio of fluazifop-acid in two soils was approximately 

82:18 at two days after application of fluazifop-butyl, and ranged from 93:7 to 95:5 from 3 to 12 

weeks after application; however, in a third loamy sand soil, the R:S ratio was 64:36 at 3 weeks 

after application of fluazifop-butyl and was 92:8 at 12 weeks (MRID 87493, 92067032, 162455). 

When the S-enantiomer of fluazifop-butyl was applied to a sandy loam soil (British 

classification), it was hydrolyzed to fluazifop-acid which gradually changed to 98% present in 

the R form over 7 days (MRID 162455). Negre et al. (1993) reported that the S-enantiomer of 

 

2

 Transmittal of EFED list B Review of Fluazifop-butyl and fluazifop-p-butyl (Case # 2285; Chemical #, 122805, 

122809; Memo from A. Rispin dated March 4, 1991). 

3

 The differing toxicity of the enantiomers is also illustrated by the differences in the effectiveness of the different 

enantiomers as herbicides. 

N

C

F

F

F

O

O C

CH3

C

O

O C

H2

C

H2

C

H2

CH3

H
Page 13 of 78 

fluazifop-acid was degraded at a much faster rate than the R-enantiomer by a mixed microbial 

culture, and indicated that the change in the ratios was not a result of the conversion of the S 

form to the R form but a result of different rates of degradation. This was supported by showing 

that two different rates of degradation existed. Enantioselective degradation and enantiomer 

interconversions were also reported for chiral phenoxyalkanoic acid herbicides with selective 

conversion to or enrichment of the R enantiomer (Muller and Buser 1997). Stereoselective 

metabolism and enantiomer interconversions often depend on the microbial species present and 

more information is needed to predict the behavior of the enantiomers in the natural environment 

(Muller and Buser 1997; Polarco et al. 1999; Qin et al. 2006). For example, preferential 

degradation of the S isomer of dichlorprop and mecoprop was observed in soil and different 

stereoselectivity may occur in different media (Wang et al. 2005; Qin et al. 2006). Finally, some 

compounds have been shown to undergo enantiomerization in polar solvents, alcohols, and water 

and it is possible that fluazifop-p-butyl and fluazifop-p-acid may racemize, e.g., form equal 

amounts of the R and S enantiomers, in water (Qin and Gan 2007; Lee 1989). 

These studies suggest that information on the R enantiomer should be adequate as fluazifop-pacid is expected to be applied to soils and the S form is either degraded faster or converted to the 

R form in soil. Given that there is no clear trend for how enantiomer-selectivity occurs in the 

environment, the exposure may be viewed as the exposure to total residues of fluazifop-acid, 

with assumptions that fluazifop-acid may be present in the R or S form or as a mixture of the 

enantiomers and this assumption will be conservative for the purposes of risk assessment. 

Hence, the racemic mixture and R forms are reviewed together here as the environmental fate of 

both forms is relevant to the environmental fate assessment. 

 4.3. Physico-chemical Properties of Fluazifop-p-butyl and Related 

Compounds

Physical and chemical properties can be used to identify a priori the potential behavior of a 

chemical in the environment. Table 4 provides a summary of the physico-chemical properties of 

fluazifop-p-butyl and related compounds. 

Fluazifop-p-butyl, with vapor pressure in the range of 2.25 x 10-7 to 1.7 x 10-6 torr, is not likely 

to volatize substantially at environmental temperatures (MRID 47272601, Corbin et al. 2006). It 

is slightly soluble (MRID 47272601) with a higher affinity for organics than for water (MRID 

47272601; US EPA 2004) and has the potential to accumulate in organisms. 

Fluazifop-acid and fluazifop-p-acid are weak acids. At typical environmental pHs, fluazifopacid is mainly in anionic form (assuming a pKa of 3.12, 88% is ionized at pH 4, 98% ionized at 

pH 5, and greater than 99% ionized at pH 5.5 and higher). It is highly soluble in water and it is 

expected to have a higher affinity for organics and lower solubility in its neutral form, e.g., at 

lower pH. 
Page 14 of 78 

Finally, the estimated vapor pressure of fluazifop-acid indicates it is borderline between semivolatile and non-volatile.4

 While volatility is expected to be low for both fluazifop-acid and 

fluazifop-butyl, volatilization under some conditions cannot be ruled out because fluazifop-butyl 

has been detected in air in an agricultural area (White et al. 2006) and the vapor pressure of 

fluazifop-acid is estimated. Fluazifop-p-butyl was detected at low concentrations (0.02-0.07 

ng/m3

) in air at two potato farm sites in Prince Edward Island, Canada (White et al. 2006). The 

authors noted that these were among the first reported detections of fluazifop-p butyl in air. The 

Agency is not aware of any other studies that have found either fluazifop butyl or acid in the air. 

Table 4. Summary of Physico-Chemical Properties of Fluazifop-p-butyl and related Compounds1. 

Property Fluazifop-p-butyl Fluazifop-butyl Fluazifop-p-acid 

Empirical Formula C19H20F3NO4 C19H20F3NO4 C15H12F3NO4

Molecular weight 

(g/mole) 383.372

 383.37 327.26 

Boiling Point (oC) 

Thermal decomposition begins at 100o

C 

(PAI)5 

164.52

Slight decomposition starts at 370oC 

(TGAI)5 

165 at 0.02 mmHg4 

Density (g/mL) 

1.22 at 20o

C(PAI)5, 11

1.21 at 20C (TGAI) 5, 11 

1.20 g.cm-3 (TGAI)11, 12 

1.213 

1.20 g.cm-3 (TGAI)11, 12

Dissociation Constant, 

pKa 

No pKa between pH 1 and 12.05

3.1 (PAI)12 3.1 (PAI)12 3.1272.78

Vapor Pressure (torr) 

9.0 x 10-7 at 20o

C5

1.7 x 10-6 at 25o

C5

2.25 x 10-7 at 20o

C12

4.13 x 10-7 at 20o

C4 

4.5 x 10-7 at 20oC12

Henry’s Law Constant 

(atm-m3/mole) 4.86 x 10-7 at 20o

C (estimated)5 1.8 x 10-7 at 20o

C4

2.11 x 10-7 at 25oC3 0.037 (estimated)7

Water Solubility 

(mg/L) 

0.935

1.0 (PAI)12, 13

1.0 at pH 6.54

27 

1.0 (PAI)12, 13 

78010

Log octanol-to-water 

partition coefficient 

(log Kow) 

>5.3 at 25o

C5 

4.5 at 20C2,12 4.5 at 20C3,12 3.187

 

1 Data that were not submitted in an MRID product chemistry study are not primary sources and in general, these 

data are not used in modeling. However, physico-chemical properties are sometimes used when no primary 

data are available or better information is available from other sources. Primary data are shown in bold. 

2 Data from TRED Case No. 2285 completed on August 11, 2004. 

3 Data from EU Regulatory / Evaluation Data / EU Annex III PIC DGD: 

http://sitem.herts.ac.uk/aeru/ppdb/en/Reports/324.htm (accessed September 03, 2014). 

4 Pesticide Manual (Combined File), 9th & 10th Ed., British Crop Protection Council, 1991 and the Royal Society 

of Chemistry, 1994, as reported in the United States Agricultural Research Service (ARS) handbook at: 

http://www.ars.usda.gov/Services/docs.htm?docid=14199 (accessed August 28, 2014). 

5 Data from MRID 47272601 and are provisional values pending complete review of the study. 

6 Agrochemicals Handbook, 2nd Edition, RSC, Nottingham, UK. 1987 as reported in the U.S. Agricultural 

Research Service (ARS) handbook at: http://www.ars.usda.gov/Services/docs.htm?docid=14199 (accessed 

August 28, 2014). 

 

4

 Fluazifop-acid is considered non-volatile based on criteria described in Corbin et al. 2006; however, pesticides 

with vapor pressures of 0.83 and 0.024 mPa, near the estimated vapor pressure of fluazifop-acid, have been found in 

remote environments, indicating that they underwent atmospheric transport and are semi-volatile (Daly et al. 2007; 

Gouin et al. 2004). 
Page 15 of 78 

7 Data from National Library of Medicine, ChemIDplus at http://chem.sis.nlm.nih.gov/chemidplus/chemidlite.jsp

(accessed August 28, 2014). Value is reported for racemic fluazifop-acid. 

8 An environmental fate summary (From Will Garner 03/24/1982) reported that the pKa of fluazifop-acid was 

2.7. 

9 Reported by registrant in metabolism study, see MRID 46190602. 

10 Based on criteria in FAO 2000. (pH not reported) 

11 PAI = Pure Active Ingredient; TGAI = Technical Grade of the Active Ingredient. 

12 Data from MRID 92067999 (2004). The data has been reviewed by USEPA Health Effects Division. 

13 Solubility at both pH 5.0 (buffered water) and pH 6.5 (pure water). 
Page 16 of 78 

4.4. Environmental Fate and Transport 

Abiotic Degradation 

Abiotic degradation rates for fluazifop-butyl and fluazifop-p-butyl are similar. Hydrolysis rates 

for fluazifop-butyl and fluazifop-p-butyl decreased with pH, where half-life of fluazifop-p-butyl 

at pH 9 is 0.4 days, 78 days at pH 7 and showed no degradation at pH 5 (MRID 41598001). 

Conversely, fluazifop-acid and fluazifop-p-acid showed no signs of degradation by hydrolysis in 

water (Negre et al. 1988; MRID 46190601). Fluazifop-butyl and fluazifop-p-butyl were 

essentially stable to photolysis in soil (MRID 93788, 93789, 41598002). No acceptable study is 

available for the photolysis of both fluazifop-butyl and fluazifop-p-butyl in water, but a 

supplemental study showed fluazifop-p-acid with a half-life of 16.3 days (MRID 49188701). 

Overall, these results indicate that degradation from physical processes will play a minor role in 

fluazifop-butyl and fluazifop-acid degradation because microbial degradation rates were 

substantially faster than the chemical degradation rates. 

Biotic Degradation

Fluazifop-butyl and Fluazifop-p-butyl 

Aerobic and anaerobic degradation of fluazifop-butyl and fluazifop-p-butyl can be rapid, 

especially in moist soils and aerobic aquatic systems. Both compounds were shown to degrade 

rapidly in soil studies within 2 hours to less than 2 days (MRID 87493, 92067033, 162455, 

46190605; Smith 1987). Degradation of fluazifop-butyl may be slower from aerobic and 

anaerobic processes in some soils under drier conditions, probably because of decreased 

microbial activity (Negre et al. 1988; Smith 1987). The primary degradation pathway is via 

microbially mediated hydrolysis (Figure 2). Overall, these results indicate that in most use 

scenarios, soils, and aerobic conditions, fluazifop-butyl and fluazifop-p-butyl will rapidly (within 

2 hours) hydrolyze to the corresponding fluazifop-acid (MRID 87493, 46190605, 162455); 

However, when the soil is dry or has little microbial activity, it will degrade more slowly. 

Fluazifop-acid and Fluazifop-p-acid 

The primary mechanism of degradation for fluazifop-p-acid and fluazifop-acid is also aerobic 

degradation, primarily through microbially-mediated hydrolysis of the ester linkage between the 

fluazifop and the butyric acid. Further degradation break the ether linkages between the rings 

and the propanoic acid moiety. Anaerobic degradation occurs at a slower rate than aerobic 

metabolism. Half-lives of fluazifop-p-acid and fluazifop-acid in aerobic soils ranged from 2 - 12 

days (MRID 46190602, 87493, 92067032; Kah et al. 2007).5

 In an aerobic water-sediment 

metabolism study, half-lives of fluazifop-p-acid ranged from 13.7 – 108 days (MRID 46190605). 

On the other hand, the half-lives of the racemic mixture of fluazifop-acid in an anaerobic flooded 

soil study ranged from 49 – 186 days (MRID 87493, 92067033). All aerobic and anaerobic soil 

and aquatic metabolism studies are summarized in Table 6, 7, and 8. 

 

5

 These half-lives include half-lives calculated using the total residues of the fluazifop-butyl + fluazifop-acid 

because not enough data was available to estimate degradation of the parent and these were the supplemental values 

established for use in risk assessment (DER addendum 10/26/2003). 
Page 17 of 78 

Figure 2. Degradation Pathway of Fluazifop-p-Butyl 

The names of compounds are available on Table 5 and can be identified by the number in parentheses. Transient 

degradates include quinol (VI) and benzoquinone (VII) 

Field Studies

Terrestrial field dissipation studies indicate that degradation of fluazifop-butyl and fluazifop-pbutyl in soil are highly variable and may be pH dependent and substantially influenced by soil 

type. Fluazifop-p-butyl may rapidly degrade or remain in soil up to 13 days and fluazifop-acid 

has the potential to persist in soil for days to weeks. 

Dissipation of fluazifop-butyl was examined in four supplemental terrestrial field dissipation 

studies including five different locations or soils. With the exception of one study, fluazifop-pbutyl and fluazifop-butyl half-lives ranged from rapid degradation at time 0 to 1.5 days (MRIDs 

41598003, 41900605, 87495, 49193104). However, one field study conducted on a plot of sandy 

loam soil planted with cotton in California showed fluazifop-butyl with a half-life of 13 days 

(MRID 41598004), which is considerably longer than the laboratory studies or the other field 

dissipation studies would suggest. Although there is no evidence that climate, enantiomerselectivity, or soil pH played a role in this study, drier conditions and precipitation amount may 

have contributed to the longer half-life of fluazifop-butyl in the California study. The studies 

(I)

Further 

degradation 

to CO2 

(X) 

(VII)

(VI)

(IV)

(III)

(II)

N

C O OC

H

CH3

C

F

F

O

O C

H2

C

H2

C

H2

CH F

N

C O OC

H

CH3

C

F

F

O

OH F

NH

F3C O

N

F3C O OH

OH O

H

C

CH3

C

OH

O

O O

HO OH
Page 18 of 78 

MRIDs 41900605 and 49193104 documented a combined rainfall and irrigation of 33 inches and 

98.2 inches, respectively for the duration of the studies. Conversely, MRID 41598004 only 

showed a combined rainfall and irrigation of only 15.9 inches, which was substantially less than 

the amount the other two studies received. Thus, the result from this study may be regarded as a 

low-end field dissipation half-life for fluazifop-butyl. 

Further, two of the above studies are considered supplemental due to the fact that the soil was 

rototilled after application (MRIDs 41598003 and 41900605). These studies are considered as 

having a great deal of uncertainty because rototilling confounds the routes of dissipation and the 

results cannot be used to understand leaching; however, the estimates reported may be 

considered as a lower bound of potential field dissipation for fluazifop-butyl and fluazifop-acid 

and provide information on what is expected in fields that are rototilled after application. The 

results from these studies are summarized in Table 6 and 7. 

Degradates 

The most significant degradates of fluazifop-p-butyl and fluazifop-butyl are fluazifop-acid and 

fluazifop-p-acid. Fluazifop-acid, enantiomer unspecified, reached maximums of 70.2 to 90.3% 

of total radioactivity recovered in aerobic soil and anaerobic flooded soil metabolism studies 

with maximums occurring between 2 and 315 days. Fluazifop-p-acid reached maximums of 8.5 

to 97.8% of applied equivalents or total radioactivity recovered in metabolism studies with 

maximums occurring between 2 and 30 days. Other major degradates that were measured at 

greater than ten percent of applied equivalents or total radioactivity recovered includes 2-

hydroxy-5-trifluoromethylpyridine (degradate X), 4-(5-Trifluoromethylpyridin-2-yloxy) phenol 

(degradate IV), SYN546933, and R201189. The maximum concentrations of these compounds 

are summarized in Table 5. 

Half-lives of both fluazifop-acid and degradate X are greater than half-lives for fluazifop-butyl. 

The dissipation half-lives reported for fluazifop-acid in an acceptable field study ranged from 1.5 

to 2.08 days in a bare plot after 3 applications, 2.3 to 2.73 days after 2 applications in a soybean 

cropped plot and 2.35 to 23.3 days in the soybean leaf disks after 2 applications. Meanwhile, 

degradate X was reported to have the calculated half-life of 339 days at the bare plot and 224 

days at the soybean cropped plot (MRID 49193104). Half-lives of fluazifop-acid from other 

submitted field studies classified as supplemental ranged from 5 to 83 days. These studies may 

still be considered as a lower-end of potential field dissipation for fluazifop-acid. 
Page 19 of 78 

4.5 Transformation Products 

Six degradates were measured at greater than ten percent of applied equivalents or total radioactivity recovered incl

fluazifop-p-acid, 2-hydroxy-5-trifluoromethylpyridine (degradate X), 4-(5-Trifluoromethylpyridin-2-yloxy) phenol SYN546933, and R201189. Table 5 lists the degradates of fluazifop-p-butyl, including their maximum and final codioxide, residues that are well sorbed to soil, and an unidentified compound similar to diclofop-methyl. 

Table 5. Fluazifop-p-butyl and Its Environmental Transformation Products. A

Code Name/ Synonym Chemical Name Chemical Structure Study Guideline MRID System 

PARENT

Fluazifop-p-butyl IUPAC: butyl (R)-2-{4-[5-

(trifluoromethyl)-2-pyridyloxy]phenoxy} propionate

CAS No.: 79241-46-6

Formula: C19H20F3NO4

MW: 383.36 g/molSMILES: 

n1cc(C(F)(F)F)ccc1Oc2ccc(OC(C)C(=O)OCCCC)cc2

MAJOR (>10%) TRANSFORMATION PRODUCTS 

Fluazifop-p-acid IUPAC: (R)-2-(4-((5-

(trifluoromethyl)-2-pyridinyl)oxy)phenoxy) propanoic acid

Formula: C15H12F3NO4

MW: 327.26 g/molSMILES: O=C(O)[C@H](Oc2ccc(Oc1ncc(cc1)C(F)(F)F)cc2)C

835.2120 41598001 pH 7 

pH 9 

835.4100 87493 clay loam 835.2410 41598002 irradiated 835.4200 87493 clay loam 835.4300 46190605 water 

total system 

835.6100 49193104

Bare plot 

Cropped plot 

N

C

F

F

F

O

O C

CH3

C

O

O C

H2

CH2

CH2

C

H
Page 20 of 78 

Code Name/ Synonym Chemical Name Chemical Structure Study Guideline MRID System Degradate X / Compound X / R154719 / CGA 142110 

IUPAC: 5-(Trifluoromethyl)pyridin-2-ol CAS: 5-(trifluoromethyl)-2(1H)-pyridinone CAS No.: 33252-63-0 Formula: C6H4F3NO 

MW: 163 g/molSMILES: c1cc(ncc1C(F)(F)F)O

835.2410 41598002 irradiated 835.4100 87493 sandy loam 835.4300 46190605

water 

total system 

835.6100 49193104 bare plot 

cropped plot 

Degradate IV / CGA181847 / R150397 

IUPAC: 4-(5-Trifluoromethylpyridin-2-yloxy)phenolCAS No: 69045-85-8

Formula: C12H8F3NO2 

MW: 255.20 g/mol SMILES: nlcc(C(F)(F)F)ccc 

1Oc2ccc(O)cc2

835.2240 49188701 irradiated 835.4300 46190605

sediment 

total system 

Degradate III IUPAC: 2-(4-Hydroxyphenoxy) propionic acid

Formula: C9H12O4 CAS No.: 67648-61-7 MW: 182.17 g/mol

NA NA NA 

R201189 Formula: C14H10F3NO3 

SMILES: C1=C(C=NC(=C1)OC2=CC=C(C=C2)OC(C)=O)C(F)(F)F

835.2240 49188701 irradiated 

SYN546933 Formula: C6H4F3NO

SMILES: C1(=CC2C1C(N2[H])=O)C(F)(F)F 835.2240 49188701 irradiated 

Unidentified compounds 

NA 

NA 

835.2240 49188701 irradiated 835.4100 46190602 Sandy clay loam 835.4300 46190605 Total system 

OH O

HCCH3

C

OHO

N

F3C O OH

NH

F3C O
Page 21 of 78 

Code Name/ Synonym Chemical Name Chemical Structure Study Guideline MRID System Carbon dioxide IUPAC: Carbon dioxide 

Formula: CO2

MW: 44 g/molSMILES: C(=O)=O 

835.4100 49010602 Loam 835.4300 46190605 Total system 

Unextracted residues NA NA 

835.4100 49010602 Loam 835.4100 87493 clay loam 835.4200 87493 sandy loam 835.4300 46190605 Total system 

A AR means “applied radioactivity”. MW means “molecular weight”. LOD means “limit of detection”. NA means “not applicable”. 
Page 22 of 78 

Mobility 

Fluazifop-p-butyl 

No acceptable studies on sorption of fluazifop-p-butyl and fluazifop-butyl have been submitted. 

However, in a supplemental terrestrial field dissipation study, fluazifop-p-butyl was not detected 

(level of quantitation 1.0 ppb) under the depth of 3 inches at both sand bare plot and sand 

soybean cropped plot in Georgia during the 13 days sampling intervals with 3 applications 

(MRID 49193104). 

Fluazifop-p-Acid 

Measured KF values for fluazifop-p-acid ranged from 0.27 to 13.4 L/kg and KOC values of 25.93 

– 310.8 across various soils, indicating that fluazifop-p-acid is mobile to moderately mobile 

(classification based on FAO 2000; MRID 46190603; Kah and Brown 2007). 

Adsorption appeared to be related to pH, with increasing sorption at lower pH’s (pH of soils 

ranged from 5.3-6.8) most likely due to the association state of the acid and the pH-dependent 

cation exchange capacity of most soils. As fluazifop-p-acid and fluazifop-acid will be present in 

the anionic form at most environmental pH values, they are expected to be highly mobile. 

Anions (negatively-charged ions) tend to be weakly sorbed to most soils (in effect, repelled by 

soil matrix surfaces which are generally negatively charged). Generally speaking, other factors 

being the same, mobility is expected to decrease with pH for acidic/anionic compounds as more 

of the compound will be present in its neutral form. 

These results suggest that fluazifop-p-acid has the potential to leach into groundwater and this is 

consistent with observation of leaching in the field dissipation studies (MRIDs 49193104 and 

41598004). 

Degradate X 

All applied 14C labeled degradate X was measured in water in batch equilibrium studies with a 

sand, two sandy loam soils, and a clay soil (MRID 41900604). A terrestrial field dissipation 

study in Tift County Georgia sand bare plot detected the presence of degradate X (1.4 ppb) at 12-

18 inch soil depth on day 450, although samples below the depth of 18 inch was not analyzed 

(MRID 41598004). Additionally, a recent supplemental adsorption and desorption study, was 

performed on two U.S. soils and two British soils indicated that degradate X is highly mobile 

with the KOC range of 17-37 L/kg-OC (MRID 49193101). Thus, based on its measured half-lives 

of 108 to 339 days in terrestrial field dissipation studies, its mobility, and its propensity to stay in 

water, degradate X has the potential to move into groundwater (MRID 41900605, 49193104).

 
Page 23 of 78 

Bioconcentration/Bioaccumulation 

Bioconcentration was examined in bluegill sunfish and channel catfish. Bioconcentration factors 

in bluegill sunfish are summarized in Table 6 and ranged from approximately 200 to 400. 14Cconcentrations in tissue fell rapidly after exposure was stopped with greater than 97 percent 

eliminated during depuration. Bioconcentration/bioaccumulation is not expected to be a 

significant route of exposure because depuration occurs rapidly and bioconcentration factors are 

low. 

In a study examining bioconcentration in channel catfish, radiolabeled (14C-phenyl and 14Cpyridyl) fluazifop-butyl was applied at 0.5 kg a.i./ha to a loamy sand soil. After 14 days aerobic 

incubation, the soil was flooded and channel catfish (Ictalurus punctatus) were added to the 

system for an exposure period of up to 65 days. After 28 and 65 days exposure, fish were 

transferred to flowing, uncontaminated water for 14 and 21 days, respectively. Soil, water, and 

fish (muscle, viscera, and whole fish) were analyzed for 14C-residues at regular intervals. In the 

whole fish, the maximum bioconcentration factor (BCF=concentration in fish 

tissue/concentration in water) measured was 2.1, equal to 0.07 mg fluazifop-acid equivalents/kg 

wet weight the maximum muscle and viscera bioconcentration factors were 1.1 and 8.0, 

respectively. The concentration of 14C-residues in the fish fell rapidly during depuration with 

over 70% of the residues eliminated during depuration. 

Table 6, Table 7, and Table 8 summarizes the environmental fate properties and studies of 

fluazifop-p-butyl, fluazifop-butyl, fluazifop-p-acid, fluazifop acid, and degradate X. 
Page 24 of 78 

Table 6. Summary of Environmental Fate Studies for Fluazifop-p-butyl and Fluazifop-butyl1

MRID Number 

or Reference 

(Year)

Study Type Media

Half-Life

Fluazifop-p-butyl Fluazifop-butyl

41598001 (1989) Hydrolysis Buffered water pH 5: No evidence of degradation

pH 7: 78 days

pH 9: 0.4 days

--

41598002 (1989) Soil Photolysis Loam soil, 25°C 195 days --

87493 (1981) 4

92067032 (1990) 4

92067033 (1990) 4

Aerobic soil Sandy loam, 18 Acres, 20°C, pH 6.0

Calcareous clay loam, Gore Hill; 20°C pH 7.4

Loamy sand, Frensham, 20°C, pH 5.4

Fen peat, Rosedean, 20°C, pH 6.7

-- 1.94 days9

<2 days2

<2 days2

<2 days2

162455 (1984)4, 8 Aerobic soil Sandy loam, British soil 2 hours; S-form also 2 hours --

46190605 (1999) 4 Aerobic aquatic 

metabolism 

Water/sand sediment from England

Water pH 7.75

Sand sediment pH 5.5

Water/sandy loam system from England

Water pH 7.6

Sandy loam sediment pH 8.1

<2 hours

<4 hours

--

87493 (1981) 4

92067032 (1990) 4

92067033 (1990) 4

Anaerobic 

flooded soil

All British Soils, 20C, pH 6.0- 7.4

Sandy loam, 18 Acres

Calcareous clay loam, Gore Hill

--

< 2 – 2 days

41598003

41900605 (1989)5

Terrestrial Field 

Dissipation

Planted with cotton in Visalia, CA

Sandy loam (pH 7.3)

Loam soil (pH 7.2)

--

1.5 days

1.5 days

41598004 (1989) Terrestrial Field 

Dissipation

Sandy loam soil planted with cotton from 

Porterville, CA; (pH 7.4-8.1)

-- 13 days

87495 (1981)

92067034 (1990)

Terrestrial Field 

Dissipation

Sandy loam pH 5.6 of Goldsboro, NC

Silty clay loam pH 6.0 from Champaign, IL

Fine sandy loam pH 8.4 of Visalia, CA

Silty loam pH 5.7 from Vicksburg, MS

-- Undetected at time 0

Undetected at time 0

Undetected at time 0

Undetected at time 0
Page 25 of 78 

MRID Number 

or Reference 

(Year) 

Study Type Media 

Half-Life 

Fluazifop-p-butyl 

49193104 (2013) Terrestrial Field 

Dissipation 

Tift County, GA 

Sand, pH 6.3, Bare plot 

Sand, pH 7.2, Soybean cropped plot 

<2.0% at time 0 <2.0% at time 0 

93796 

92067035 (1990)7

Fish 

bioconcentration 

factors (steadystate, total 

residues); 

depuration rate 

Bluegill Sunfish 

Whole Fish 

Muscle 

Viscera 

Water 

-- 9

1 Abbreviations: DER = data evaluation record; DT50 = dissipation time of 50% of the chemical 2 An EFED Fate summary dated 2/17/1982 estimated a half-life less than 2 days because that was the earliest sampling point after applic

record (DER) completed on 10/26/1992 indicated the results supported a half-life of less than a day. 

3 The values shown are the half-life ± the standard error. 4 Soils were classified using the British classification system. 5 The plots in these studies were rototilled for weed control after the application of fluazifop-butyl and, in some cases, residues could no

in much reduced levels after rototilling. The values in these studies may be considered a lower bound for rates of dissipation. 

6 The study showed minimal bioconcentration of total radioactivity which provides a conservative estimate of bioconcentration of fluazi

p-acid. 

7 As only some of the residues in the viscera were fluazifop-acid, actual bioconcentration factors will be lower. 

8 In Review: Study results are provisional as reviews are currently in progress. 9 Calculated half-life of parent + acid in both pyridyl and phenyl labels. 
Page 26 of 78 

Table 7. Summary of Environmental Fate Studies for Fluazifop-p-acid and Fluazifop-acid 1 

MRID Number or 

Reference (Year) 

Study Type Media Half-Life 

 Fluazifop-p-acid F

46190601 (1995) Hydrolysis Sterile buffered solution, 25°C pH 5: No evidence of degradation 

pH 7: No evidence of degradation pH 9: No evidence of degradation 

49188701 (2013) Aqueous Photolysis Sterile water 25°C, pH 7 16.3 days 

87493 (1981)3

92067032 (1990)3

Aerobic soil Sandy loam, 18 Acres, 20°C, pH 6.0 

Calcareous clay loam, Gore Hill 20°C, 

pH 7.4 

Loamy sand, Frensham, 20°C, pH 5.4 

Fen peat, Rosedean, 20°C, pH 6.7 

-- 

2.47 d

3.78 d

 11.9 d

46190602 (1998) Aerobic soil Silt loam, pH 7.0, 20°C 

Sandy clay loam, pH 5.8, 20°C 

Sandy loam, pH 7.2, 20°C Sandy loam, pH 5.3, 20°C 

Sandy clay loam, pH 7.1, 20°C 

Clay loam, pH 7.7, 20°C 

Linear:10.5d; Nonlinear DT50: 8.3d 

Linear: 9.8d; Nonlinear DT50: 8.2d Linear: 7.5d; Nonlinear DT50: 2.7d 

Linear:13.9d; Nonlinear DT50: 9.1d 

Linear: 9.6d; Nonlinear DT50: 3.3d Linear: 9.1d; Nonlinear DT50: 2.3d 

46190605 (1999)3 Aerobic watersediment Water/sand sediment from England 

Water pH 7.75 

Sand sediment pH 5.5 

Water/sandy loam system from 

England 

Water pH 7.6 

Sandy loam sediment pH 8.1 

Phenyl label; Linear = 108 d (7-100 

day data); Observed DT50 = 100 d 

Pyridyl label; Linear = 13.7 d 

Observed DT50 = 30-59 d 

Phenyl label; Linear = 23.2 d 

Observed DT50 = 30-59 d 

Pyridyl label; Linear = 43.9 d 

Observed DT50 = 30-59 d 

87493 (1981)3

92067033 (1990)3

Anaerobic 

flooded soil 

Sandy loam, 18 Acres, 20C, pH 6.0 -- 

47 da
Page 27 of 78 

MRID Number or 

Reference (Year) 

Study Type Media Half-Life 

 Fluazifop-p-acid F

Calcareous clay loam, Gore Hill, 

20C, pH 7.4 

152 d

46190603 (1998)3 Leaching & 

Adsorption 

(ADS) 

Silt loam (Soil A) 

Sandy clay loam (Soil B) 

Sandy loam (Soil C) 

Sandy loam (Soil D) 

Sandy clay loam (Soil E) 

Clay loam/ loam (Soil F) 

Koc: 80.3 L/kg 

Koc: 63.3 L/kg 

Koc: 200.4 L/kg 

Koc: 111.8 L/kg Koc: 139.3 L/kg Koc: 310.8 L/kg 

41598003 41900605 

(1989) 

Terrestrial Field 

Dissipation 

Planted with cotton in Visalia, CA 

Sandy loam (pH 7.3) 

Loam soil (pH 7.2) 

-- 

41598004 (1989) Terrestrial Field 

Dissipation 

Sandy loam soil planted with cotton 

from CA (pH 7.4-8.1) 

-- 

No leaching 

87495 (1981) 

92067034 (1990) 

Terrestrial Field 

Dissipation 

Sandy loam pH 5.6, Goldsboro, NC 

Silty clay loam pH 6.0,Champaign, IL 

Fine sandy loam pH 8.4, Visalia, CA 

Silty loam pH 5.7, Vicksburg, MS 

-- 

49193104 (2013) Terrestrial Field 

Dissipation 

Tift County, GA 

Sand, pH 6.3, Bare plot 

Sand, pH 7.2, Soybean cropped plot 

Soybean leaf disk 

1.5 - 2.08 days 2.3 - 2.73 days 

2.35 – 23.3 days (tR IORE) 

93796 

92067035 

(1990) 

Fish 

bioconcentration 

factors (steadystate, total 

residues); 

depuration rate 

Bluegill Sunfish 

Viscera 

Water 

-- 

1 Abbreviations: DER = data evaluation record; DT50 = dissipation time of 50% of the chemical 2 The half-life was calculated using single first-order on the combination of both phenyl & pyridyl labels. 

3 All British Soils. Soils were classified using the British classification system. 
Page 28 of 78 

Table 8. Summary of Environmental Fate Studies for Degradate X1 Abbreviations: DER = data evaluation record; DT50 = dissipation time of 50% of the chemical 2 The plots in these studies were rototilled for weed control after the application of fluazifop-butyl and, in some cases, residues could no

in much reduced levels after rototilling. The values in these studies may be considered a lower bound for rates of dissipation. 

3 The dissipation of the degradate 5-trifluoromethyl-pyrid-2-one (degradate X) does not agree with the data reported in the aerobic meta

laboratory studies (A. Abramovitch; EFED Fate Summary 11/9/1992; DP Barcode D157692, D157723, D165770). However, the study lower bound for rates of dissipation. 

4 All British Soils. Soils were classified using the British classification system. 

MRID Number or 

Reference (Year) 

Study Type Media 

D

87493 (1981)4 Aerobic soil Sandy loam, 18 Acres, 20°C, pH 6.0 

Calcareous clay loam, Gore Hill 20°C, pH 7.4 

49193101 (1998) Adsorption & Desorption ERTC Sandy loam, pH 6.0; Whitakers, North Carolina 

Hyde Farm Sandy clay loam, pH 7.5; Berkshire, UK 

Kenny Hill Sandy loam, pH 8.5; Suffolk, UK 

NRTC Silty clay, pH 5.6; NRTC, Illinois 

K

K

Koc: 

K

41598003 (1989)2

41900605 (1990) 

Terrestrial Field 

Dissipation 

Sandy loam, (pH 7.3) 

Loam soil, (pH 7.2) 

41900606 (1990)3 Terrestrial Field 

Dissipation 

Sandy loam soil, (pH 7.1); planted with cotton 

49193104 (2013) Terrestrial Field 

Dissipation 

GA Sand, pH 6.3, Bare plot 

GA Sand , pH 7.2, Soybean cropped plot 

(1.4 ppb detected 
Page 29 of 78 

5. Receptors 

Consistent with EFED’s standard methodology, the risk assessment for fluazifop will rely on a 

surrogate species approach. Toxicological data generated from surrogate test species, which are 

intended to be representative of broad taxonomic groups, are used to extrapolate to potential 

effects on a variety of species (receptors) included under these taxonomic groupings. 

The Agency evaluates the potential for adverse effects as a result of fluazifop usage. The most 

sensitive endpoint for each taxon is used for RQ calculations. Assessment endpoints include 

direct toxic effects on the survival, reproduction, and growth of terrestrial and aquatic life, as 

well as indirect effects, such as reduction in prey base and/or modification of habitat. The 

evaluated taxa include freshwater fish, freshwater aquatic invertebrates, birds, small mammals, 

terrestrial invertebrates, algae, and terrestrial plants. 

Acute (short-term) and chronic (long-term) toxicity information is characterized based on 

registrant-submitted studies. Other sources of information, including use of the acute probit dose 

response relationship to establish the probability of an individual effect and reviews of the 

Ecological Incident Information System (EIIS), are conducted to further refine the 

characterization of potential ecological effects associated with exposure to fluazifop. 

Estuarine/marine invertebrates are the most sensitive aquatic species. Fluazifop-p-butyl is highly 

acutely toxic to the Pacific oyster (Crassostrea gigas), with a 48-hr EC50 value of 0.083 mg acid 

equivalents (ae)/L. Fluazifop-p-butyl is highly toxic to freshwater fish, with a reported 96-hr 

LC50 value of 0.45 mg ae/L to the Bluegill Sunfish (Lepomis macrochirus). Fluazifop-p-butyl is 

moderately toxic to freshwater invertebrates and estuarine/marine fish with a reported 48-hr EC50

value of 5.14 mg ae/L to the Water Flea (Daphnia magna), and a reported 96-hr LC50 of 6.87mg 

ae/L to the Sheepshead Minnow (Cyprinodon variegatus) respectively. In 2 studies submitted 

and currently under review, Degradate X was less toxic to Rainbow trout as well as Daphnia (96-

hr LC50 value of 240 mg/L and 48-hr EC50 value of 666 mg/L, respectively). 

Chronic exposure studies identified a freshwater invertebrate 21-d LOAEC value of 0.213 mg 

ae/L for D. magna and a freshwater fish 30-d LOAEC value of 0.203 mg ae/L for the Fathead 

Minnow (Pimephales promelas). No acceptable data were submitted for chronic toxicity to 

estuarine/marine fish or invertebrates. Therefore, an ACR6 value was obtained from the 

freshwater animal studies and applied to the acute toxicity data for estuarine/marine species to 

estimate chronic toxicity values for these species. This approach yielded a NOAEC value of 

3.10 mg ae/L for the estuarine/marine fish C. variegatus and a NOAEC value of 0.003 mg ae/L 

for the estuarine/marine invertebrate C gigas.

In birds, the acute oral LD50 for Anas platyrhynchos is 3012 mg/kg-bw and the avian dietary 

LC50 value is 4141 mg/kg-bw, practically nontoxic and slightly toxic, respectively. The avian 

reproductive toxicity data using Colinus virginianus and A. platyrhynchos resulted in NOAELs 

of 50 ppm and LOAELs of >50 ppm for fluazifop-butyl in both studies (no effects in either 

study). In laboratory rats, fluazifop-p-butyl has a dose based acute toxicity LD50 value of 2451 

 

6

 Acute toxicity endpoint value ÷ Chronic toxicity endpoint value 
Page 30 of 78 

mg/kg-bw (practically non-toxic) and a 2-generation reproduction study using fluazifop-butyl 

resulted in a NOAEL value of 80 ppm with reductions in pup weights as well as reductions in 

pup viability at 250 ppm. Fluazifop-p-butyl is slightly toxic to the honey bee with an acute 

contact LD50 of 63 μg/bee. 

No toxicity data have been submitted regarding the toxicity of fluazifop-p-butyl or acid to plants. 

Risks to monocot plants are presumed due to the fact that fluazifop-p-butyl is a selective 

herbicide intended to control monocot plants. Risks to dicot aquatic plants may be minimal due 

to the fact that it is used routinely on dicot plant crops and no incidents of damage to these 

species have been reported. However, guideline toxicity studies would allow EFED to make 

more definitive risk conclusions regarding dicot and monocot plants. Risks to algae and lichens 

are presumed to be a concern in the absence of data. Two studies (vegetative vigor and seedling 

emergence) have been recently submitted and are in review. Preliminary results suggest effects 

only to monocots. 

Table 9 and Table 10 provide a summary of the aquatic and terrestrial taxonomic groups, 

respectively, and most sensitive surrogate species tested to characterize the potential acute and 

chronic ecological effects of fluazifop. 

5.1. Effects to Aquatic Organisms 

Table 9. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for 

fluazifop-p-butyl or fluazifop-butyl 

Taxonomic 

Group 

Study Type Surrogate Species Toxicity 

Value 

(mg ai/L) 

Acute 

Toxicity 

Classification 

Source 

Freshwater fish 

Acute 

Fluazifopbutyl 

Bluegill sunfish 

(Lepomis 

macrochirus)

96 hr LC50 = 

0.45 ppm Highly toxic 00087485, 

1981 

Acute 

Deg X 

Rainbow Trout 

(Oncorhynchus 

mykiss)

96 hr LC50 = 

240 ppm 

Practically 

non-toxic 

49224402, 

1994 

(IN REVIEW) 

Chronic 

Fluazifopbutyl 

Fathead minnow 

(Pimephales 

promelas)

NOAEC= 

0.203 ppm N/A 00093808, 

1981 

Freshwater 

invertebrates 

Acute 

Fluazifopbutyl 

Water Flea 

(Daphnia magna) 

48 hr EC50 = 

5.14 ppm 

Moderately 

toxic 

00087489, 

1980 

Acute 

Deg X 

Water Flea 

(Daphnia magna) 

48 hr EC50 = 

666 ppm 

Practically 

non-toxic 

49224401, 

1982 

(IN REVIEW) 

Chronic 

Fluazifopbutyl 

Water Flea 

(Daphnia magna) 

LOAEC= 

0.213 ppm N/A 00093807, 

1981 
Page 31 of 78 

Taxonomic 

Group 

Study Type Surrogate Species Toxicity 

Value 

(mg ai/L) 

Acute 

Toxicity 

Classification 

Source 

Estuarine/marine 

fish 

Acute 

Fluazifopbutyl 46.8% 

Sheepshead Minnow 

(Cyprinodon 

variegatus) 

96 hr LC50 = 

6.8 ppm 

Moderately 

toxic 

00152173, 

1985 

Chronic 

Sheepshead Minnow 

(Cyprinodon 

variegatus) 

No data N/A NA 

Estuarine/marine 

invertebrates 

Acute 

Fluazifop-pbutyl 

Mysid Shrimp 

(Americamysis 

bahia) 

Eastern Oyster 

(Crassostrea 

virginica) 

96 hr LC50 = 

0.435 ppm 

96 hr EC50 = 

0.40 ppm 

Highly toxic 

Highly toxic 

42543201, 

1991 

41900601, 

1991 

Chronic Mysid Shrimp No data N/A N/A 

Aquatic plants 

and algae 

Vascular 

Deg X 

72 hr static Green 

Algae (Selenastrum 

capricornutum) 

EC50 = 340 

ppm 

(biomass) 

NOAEL= 

100 ppm 

LOAEL = 

200 ppm 

IN REVIEW 49224403, 

1994 

Vascular 

Green Algae 

(Pseudokirchneriella 

subcapitata) 

No inhibition 

>50% N/A 41900603, 1985 

5.2. Effects to Terrestrial Organisms 

Table 10. Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for 

fluazifop-p-butyl 

Taxonomic 

Group 

Study 

Type 

Surrogate 

Species 

Toxicity Value 

(all units in terms 

of measured active 

ingredient) 

Acute 

Toxicity 

Classification 

Source 

Birds 

Acute 

Mallard duck 

(Anas 

platyrhynchos) 

Acute Oral LD50 > 

3012 mg ai/kg-bw Practically 

non-toxic 

40829201, 

1985 

Sub-acute 

dietary 

Mallard duck 

(Anas 

platyrhynchos) 

Acute Dietary LC50 

4141.5 ppm Slightly toxic 00087481, 

1987 

Chronic 

Northern 

Bobwhite 

(Colinus 

virginianus)

NOAEL = 50 ppm 

LOAEL >50 ppm 

Fluazifop-butyl (no 

effects) 

N/A 00093802, 

1981 
Page 32 of 78 

Taxonomic 

Group 

Study 

Type 

Surrogate 

Species 

Toxicity Value 

(all units in terms 

of measured active 

ingredient) 

Acute 

Toxicity 

Classification 

Source 

Mallard duck 

(Anas 

platyrhynchos) 

NOAEL = 50 ppm 

LOAEL >50 ppm 

Fluazifop-butyl (no 

effects) 

N/A 00093801, 

1981 

Mammals 

Acute Oral 

Laboratory rat 

(Rattus 

norvegicus) 

LD50 = 2451 mg/kgbw 

Practically 

non-toxic 

00162440, 

1984 

Acute 

Inhalation 

Laboratory rat 

(Rattus 

norvegicus) 

LC50 >2.3 mg/L N/A 46082901, 

1979 

Chronic 

Laboratory rat 

(Rattus 

norvegicus) 

NOAEL = 80 ppm 

LOAEL 250 ppm 

with reductions in 

pup viablity and 

weights 

N/A 92067050, 

1981 

Insects Acute 

contact 

Honey bee 

(Apis mellifera 

L.) 

48 hr LD50 = 63 

ug/bee Slightly toxic 

00162453, 

1984 

Terrestrial 

plants nontarget 

Seedling 

Emergence 

No data N/A N/A N/A 

No data N/A N/A N/A 

Vegetative 

Vigor 

No data N/A N/A N/A 

No data N/A N/A N/A 

5.3. 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. 

Reported incidents from the EIIS database included damage to non-target terrestrial plants, sheep 

mortality and mortality to fish. 

 
Page 33 of 78 

Table 11. EIIS Pesticide Summary Report for Fluazifop (122805) 

 Incident# Date County, 

State 

Certainty Legal. Appl. 

Method 

Species Response Rt. 

Exposure 

Magnitude 

PLANTS 

 Peanuts I011838-

012 

6/4/2001 Mitchel, GA 2 UN NR Peanuts Plant 

damage 

Treated 

directly 

70 acres 

Cotton I000031-

001 

6/9/1992 LA 1 MA NR Cotton Plant 

damage 

Treated 

directly 

Unknown 

Certainty code: 0=Unrelated, 1=Unlikely, 2=Possible, 3 =Probably, 4=Highly Probable 

Legality Code: RU=Registered Use, M=Misuse, MA=Misuse (Accidental), MI=Misuse (Intentional), UN=Unknown, NR=Not 

Reported 

Table 12. EIIS Pesticide Summary Report for Fluazifop-P-butyl (122809) 

 Incident# Date County, 

State 

Certainty Legal. Appl. 

Method 

Species Response Rt. 

Exposure 

Magnitude 

AQUATIC 

 

Soybean 

I007601-

001 

7/23/1998 White, IL 2 RU Spray Catfish, 

crappie, 

bass, 

sunfish 

Mortality Rain/Pond 

Runoff 

200 

PLANTS 

Soybean I007755-

022 

6/15/1998 Clay, IN 2 UN NR Terrestrial 

Plant 

Plant 

damage 

Treated 

directly 

20 acres 

Corn I012499-

024 

5/24/2001 Cedar, IA 2 RU Broadcast Terrestrial 

Plant 

Plant 

damage 

Treated 

directly 

75 acres 

Corn I012499-

031 

5/22/2001 Carroll, IA 2 RU Broadcast Terrestrial 

Plant 

Plant 

damage 

Treated 

directly 

195 acres 

Corn I012499-

038 

5/30/2001 Ida, IA 2 RU NR Terrestrial 

Plant 

Plant 

damage 

Treated 

directly 

90 acres 

Ornamen

tal 

I023931-

065 

2012 Washten, MI 4 UN NR Terrestrial 

Plant 

Plant 

damage 

Treated 

directly 

>45% 

Ornamen

tal 

I024071-

265 

2012 Oakland, MI 2 UN Spray Terrestrial 

Plant 

Plant 

damage 

NR >45% of 

Flowers 

Residenti

al 

I024179-

100 

2012 Spokane,WA 2 UN Spray Terrestrial 

Plant 

Plant 

damage 

Treated 

directly 

>45% of 

plants 

Residenti

al 

I024179-

170 

2012 Yakima, WA 1 UN NR Terrestrial 

Plant 

Plant 

damage 

NR 1 Ajuga Plant 

Residenti

al 

I024272-

138 

2012 Licking, OH 2 UN NR Terrestrial 

Plant 

Plant 

damage 

NR >45% 

Evergreen 

Residenti

al 

I024272-

187 

2012 Roane, TN 2 UN NR Terrestrial 

Plant 

Plant 

damage 

NR >45% Roses 

Residenti

al 

I024272-

216 

2012 New Haven, 

CT 

2 UN NR Terrestrial 

Plant 

Plant 

damage 

NR >45% of 

Plants 

ANIMALS 

Field I026002-

001 

2013 IA 2 UN NR Terrestrial 

Animal 

Mortality Drift 3 Sheep 

Certainty code: 0=Unrelated, 1=Unlikely, 2=Possible, 3 =Probably, 4=Highly Probable 

Legality Code: RU=Registered Use, M=Misuse, MA=Misuse (Accidental), MI=Misuse (Intentional), UN=Unknown, NR=Not 

Reported 

6. Exposure Pathways of Concern 

The conceptual model will consider the parent compound and its acid for the drinking water 

exposure assessment and ecological risk assessment. 

The environmental fate properties and use patterns of fluazifop-p-butyl indicate that direct spray, 

spray drift, leaching for areas with shallow ground water tables, and runoff represent potential 

transport mechanisms of fluazifop-p-butyl residues to aquatic and terrestrial organisms. 
Page 34 of 78 

Drinking water and inhalation exposure pathways were screened using the SIP (Screening 

Imbibition Program) and STIR (Screening Tool for Inhalation Risk) screening methods and were 

found not to be exposure pathways of concern (no LOC exceedances are expected). Appendix C 

and D contain details on the SIP and STIR analyses. SIP and STIR are described in detail at: 

http://www.epa.gov/oppefed1/models/terrestrial/index.htm. 

7. Analysis Plan 

7.1. Stressors of Concern 

Ecological Risk Assessment 

A few different compounds are associated with the common name, fluazifop-butyl. Fluazifopbutyl (PC Code 122805) is the racemic mixture (e.g., consists of equal amounts of the R and S 

enantiomers) of butyl-2-{4-[5-(trifluoromethyl)-2-pyridyloxy]phenoxy}propionate, but has been 

cancelled. Fluazifop-p-butyl (PC Code 122809) is the R enantiomer and is more herbicidally 

active than the S enantiomer (Tu et al. 2001). Both primarily degrade, via microbial mediated 

hydrolysis, in moist soil and sediments to fluazifop-acid which can also exist in the R or S form 

(MRID 162455; 87493, 92067033, 87492, 92067032, 46190602, 46190605). 

Drinking Water Exposure Assessment 

The drinking water exposure assessment conducted to support human health risk assessment of 

fluazifop-p-butyl will incorporate model estimates of fluazifop-p-butyl residues of concern, 

which are the parent compound and its acid (USEPA, 2000), in surface and ground waters. 

Exposure estimates reported for potential acute, chronic, and cancer assessment are the 1-in-10-

year peak, 1-in-10-year annual mean, and 30-year mean in a vulnerable reservoir with a drinking 

water intake. The fluazifop-p-butyl residues of concern may be reevaluated pending receipt and 

review of additional environmental fate and toxicity data. 

7.2. Measures of Exposure 

EFED will use standard available models to evaluate potential exposures to aquatic and 

terrestrial organisms as described at http://www.epa.gov/pesticides/science/models_db.htm. For 

surface water, the measure of exposure for acute risks is the 1-in-10-year peak concentration at a 

site more vulnerable than 90% of sites where a pesticide use site occurs. For chronic risks, the 

measures of exposure are 1-in-10-year 21-day and 60-day means. For terrestrial risks the 

measure of exposure is the peak exposure on (and at the edge of) the field. 

7.3. Measures of Effect 

Toxicity data presented in Section 4 of this problem formulation will be used to calculate risk 

quotients. Any additional information submitted by the registrant or found in the open literature 

prior to conduct of the risk assessment will also be considered. The open literature studies are 

identified using EPA’s ECOTOXicology database (ECOTOX) (USEPA, 2007c), which employs 

a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, 
Page 35 of 78 

and wildlife. The evaluation of both sources of data can also provide insight into the direct and 

indirect effects of pesticides on biotic communities from loss of species that are sensitive to the 

chemicals and from changes in structure and functional characteristics of the affected 

communities. 

8. Endangered Species Assessments 

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), the 

Agency will evaluate risks to federally listed threatened and/or endangered (listed) species from 

registered uses of pesticides in registration review. The process for evaluating potential risks to 

listed species is further described at 

http://www.epa.gov/oppfead1/endanger/litstatus/riskasses.htm. 

9. Endocrine Disruptor Screening Program 

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse 

outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and 

chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, 

reproductive, and general or systemic toxicity. These studies include endpoints which may be 

susceptible to endocrine influence, including effects on endocrine target organ histopathology, 

organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, 

and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and 

chronic studies that assess growth, developmental and reproductive effects in different 

taxonomic groups. As part of its most recent registration decision, EPA reviewed these data and 

selected the most sensitive endpoints for relevant risk assessment scenarios from the existing 

hazard database. However, as required by FFDCA section 408(p), fluazifop-p-butyl is subject to 

the endocrine screening part of the Endocrine Disruptor Screening Program (EDSP). 

EPA has developed the EDSP to determine whether certain substances (including pesticide 

active and other ingredients) may have an effect in humans or wildlife similar to an effect 

produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator 

may designate.” The EDSP employs a two-tiered approach to making the statutorily required 

determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a 

chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal 

systems. Chemicals that go through Tier 1 screening and are found to have the potential to 

interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA 

will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 

testing is designed to identify any adverse endocrine-related effects caused by the substance, and 

establish a dose-response relationship between the dose and the E, A, or T effect. 

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between 

October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 

chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. A second list 
Page 36 of 78 

of chemicals identified for EDSP screening was published on June 14, 20137 and includes some 

pesticides scheduled for registration review and chemicals found in water. Neither of these lists 

should be construed as a list of known or likely endocrine disruptors. 

Fluazifop and Fluazifop-p-butyl are on List 1 for which EPA has received all the required Tier 1 

assay data. The Agency is currently reviewing all assay data received for the appropriate List 1 

chemicals and planning to make the conclusions of those reviews available in early 2015. For 

further information on the status of the EDSP, the policies and procedures, the lists of chemicals, 

future lists, the test guidelines and the Tier 1 screening battery, please visit our website.8

 

 

7

 See http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0477-0074 for the final second list of 

chemicals. 8

 http://www.epa.gov/endo/ 
Page 37 of 78 

10. Preliminary Identification of Data Gaps 

10.1. Environmental Fate 

Table 13 and 14 identify environmental fate studies by their Master Record Identification (MRID) number 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. 

Table 13. Summary of fate data requirements for fluazifop-p-butyl and fluazifop-p-acid.

Guideline 

Number

Study 

Description

40 CFR § 158

Requirements:

Terrestrial 

Outdoor Use

MRID

Number

(chemical)1

Classification

Are more data 

needed for this risk 

assessment?

Justification/Comments

Degradation Studies – Laboratory

835.2120 Hydrolysis Required 41598001 (ester)

46190601 (acid)

Acceptable

Acceptable

No 

835.2240 Photodegradation 

in water

Required 42543202 (ester)

49188701

(acid)

Unacceptable

Supplemental

No 

Not a major degradation pathway versus 

microbial degradation; ester is predicted not 

to readily photolize, similar to the acid.

835.2410 Photodegradation 

on soil

Required 41598002 (ester) Acceptable No The ester study should sufficiently represent

the acid form.

835.2370 Photodegradation

in air

Conditionally 

required

No data Not applicable No No due to low vapor pressure

Metabolism Studies – Laboratory

835.4100 Aerobic soil Required 162455 (ester)

49010602 

(degradate IV)

46190602 (acid)

Not classified 

In Review*

Supplemental 

No Although half-life data is not available for 

ester, studies has shown that ester rapidly 

degraded to acid form within 2 days. The 

data on acid would sufficiently describe the 

fate of ester. Half-life data on combined 

ester residue plus acid is available for the 

racemic mixture.
Page 38 of 78 

Table 13. Summary of fate data requirements for fluazifop-p-butyl and fluazifop-p-acid.

Guideline Number 

Study Description 

40 CFR § 158

Requirements: Terrestrial Outdoor Use 

MRID Number (chemical)1

Classification 

Are more data needed for this risk assessment? 

Jus

MRID 46190

incomplete mtransformatio

835.4200 Anaerobic soil Required No data Not applicable No Flooded soil 

racemic mixt92067033) 

835.4300 Aerobic aquatic Required 46190605 (ester 

+ acid) 

Acceptable No 

835.4400 Anaerobic aquatic Required No data Not applicable Yes An anaerobic 

required undguidance recperformed w

Mobility Studies 835.1230 835.1240 

Leaching and adsorption/desorption 

Required 46190603 (acid) Supplemental Yes for ester and acid For MRID 46

balance and nmatter. All sone soil valurisk assessmeA new adsorprequested wisoils with onmatter. 

46190604 (ester) Unacceptable 

due to heat 

sterilized soils 41900604 (acid) 

49010601 ( Degradate IV) 

Not classified 

49193101 (Degradate X) 

Supplemental 

835.1410 Volatility – 

laboratory 

Conditionally Required 

No data Not applicable No No due to low 

835.8100 Volatility – Field Conditionally 

required 

No data Not applicable No No due to low 

Dissipation Studies - Field 
Page 39 of 78 

Table 13. Summary of fate data requirements for fluazifop-p-butyl and fluazifop-p-acid.

Guideline Number 

Study Description 

40 CFR § 158

Requirements: Terrestrial Outdoor Use 

MRID Number (chemical)1

Classification 

Are more data needed for this risk assessment? 

Jus

835.6100 Terrestrial Required 49193104 (ester 

+ acid + degradate X) 

Supplemental No Although stu

study was coapproach. Arequested becsubstantially assessment. This study is uncertainties (MRID 4919

835.6200 Aquatic 

(sediment) 

Conditionally required 

No data Not applicable No

835.6300 Forestry Not required No data Not applicable No Forestry uses 835.6400 Combination and 

tank mixes 

Conditionally required 

No data Not applicable No 

Ground Water Monitoring835.7100 Ground water 

monitoring 

Conditionally required 

No data Not applicable No 

Other 

Analytical chemistry methods capable of identifying and quantifying each separate enantiomer in water 

 49193108 Unacceptable Yes Methods to d

fluazifop-aciwater are neemonitoring s

Analytical chemistry methods capable of identifying and quantifying each 

 49193107 Supplemental Yes Methods to d

fluazifop-acisoil are needstudies3
Page 40 of 78 

Table 13. Summary of fate data requirements for fluazifop-p-butyl and fluazifop-p-acid.

Guideline Number 

Study Description 

40 CFR § 158

Requirements: Terrestrial Outdoor Use 

MRID Number (chemical)1

Classification 

Are more data needed for this risk assessment? 

Jus

separate enantiomer in soil 

Validation of Analytical Method and Independent laboratory validation of parent and significant metabolites for soil and water 

Required for validation of field studies, e.g., water and soil 

49193105 Unacceptable Yes 

49193106 Supplemental Yes 

Storage stability of residues in frozen soil samples 

Required 49193102 

49193103 

Acceptable Acceptable 

No 

Bioconcentration in fish 

Conditionally Required 

No data Not applicable No Data is availa

Spray droplet size spectrum (201-1) 

Required. No data Not applicable No Data are avai

through memForce. Syngenta Crof the Spray 

*In Review: Study results are provisional as reviews are currently in progress. 1 Ester refers to the parent compound, fluazifop-p-butyl, and acid refers to the acid degradate, fluazifop-p-acid. 2 EFED Interim Policy for Stereoisomeric Pesticides (available at http://www.epa.gov/oppefed1/ecorisk_ders/stereoisomer_policy.htm) 

metabolism study (GLN 162-1/835.3300) is required as part of the minimal data set for enantiomeric enriched mixtures.”

3 EFED Interim Policy for Stereoisomeric Pesticides (available at http://www.epa.gov/oppefed1/ecorisk_ders/stereoisomer_policy.htm) 

chemistry methods capable of identifying and quantifying each separate enantiomer and chiral transformation products in soil, water, a

4 A high-performance liquid chromatography (HPLC) method was submitted to detect fluazifop-acid in water in connection with a grou

but it has not been independently evaluated and did not examine the enantiomers present (MRID 40439402). 

5 List of Spray Drift Task Force Members available at http://www.agdrift.com/Text%20pages/members.htm (accessed March 28, 2008)
Page 41 of 78 

Table 14. Summary of fate data requirements for fluazifop-butyl and fluazifop-acid.

Guideline Number 

Study Description 

40 CFR § 158

Requirements: Terrestrial Outdoor Use 

MRID Number (chemical)1

Classification 

Are more data needed for this risk assessment? 

J

Degradation Studies – Laboratory 835.2120 Hydrolysis Required 87529 Not classified No Data is av835.2240 Photodegradation 

in water 

Required 93788 Not classified No Data is av

835.2410 Photodegradation 

on soil 

Required 93789 Not classified No Data is av

835.2370 Photodegradation 

in air 

Conditionally required 

 Not applicable No No due to 

Metabolism Studies – Laboratory 835.4100 Aerobic soil Required 87493, 

92067032, 92067033 87492 

Supplemental Not classified 

No Soils used 

soils. 

835.4200 Anaerobic soil Required 87493, 

92067033 

Supplemental No Soils used 

soils. 

835.4300 Aerobic aquatic Required No data No data No Data is av835.4400 Anaerobic aquatic Required 87493, 

92067032 

Unacceptable No 

Mobility Studies 835.1230 835.1240 

Leaching and adsorption/desorption 

Required 93794 

41900604 

Not classified Unacceptable due to heat sterilized soils 

No 

Fluazifopfor use. 

835.1410 Volatility – 

laboratory 

Conditionally Required 

No data Not applicable No 

835.8100 Volatility – Field Conditionally 

required 

No data Not applicable No 

Dissipation Studies - Field 835.6100 Terrestrial Required 41598003 Supplemental No Does not 

requirem
Page 42 of 78 

Table 14. Summary of fate data requirements for fluazifop-butyl and fluazifop-acid.

Guideline Number 

Study Description 

40 CFR § 158

Requirements: Terrestrial Outdoor Use 

MRID Number (chemical)1

Classification 

Are more data needed for this risk assessment? 

J

41598004 87495 & 92067034 41900605 41900606 

Supplemental Supplemental Supplemental Unacceptable 

Supplemewere not storage stSupplemeintervals, and analyDoes not requiremData not metabolis

835.6200 Aquatic 

(sediment) 

Conditionally required 

No data Not applicable No 

835.6300 Forestry Not required No data Not applicable No 835.6400 Combination and 

tank mixes 

Conditionally required 

No data Not applicable No 

Ground Water Monitoring835.7100 Ground water 

monitoring 

Conditionally required 

40439401 Unacceptable No. Fluazifop-butyl is 

no longer registered for use. 

Unacceptmonitorin

Other 

Validation of Analytical Method and Independent laboratory validation of parent and significant metabolites 

Required for validation of field studies, e.g., water and soil 

40439402 This method has 

not been validated 

No Fluazifop

for use. 
Page 43 of 78 

Table 14. Summary of fate data requirements for fluazifop-butyl and fluazifop-acid.

Guideline Number 

Study Description 

40 CFR § 158

Requirements: Terrestrial Outdoor Use 

MRID Number (chemical)1

Classification 

Are more data needed for this risk assessment? 

J

Storage stability of residues in frozen soil samples 

Required 41598004 

40439401 

Not classified Not classified 

No 

A storage butyl for connectiodissipatioStorage swater mo

835.1730 Bioconcentration 

in fish 

Conditionally Required 

93796 & 92067035 93795 

Supplemental due to 45% of degradate in viscera not characterized. Not classified 

No The study 

bioconcenwhich proof bioconand fluaz

Spray droplet size spectrum (201-1) 

Required. Data are available. 

No data Not applicable No, Syngenta Crop 

Protection, Inc. is a member of the Spray Drift Task Force5

May be sthe Spray 

List of Spray Drift Task Force Members available at http://www.agdrift.com/Text%20pages/members.htm (accessed March 28, 2008) 
Page 44 of 78 

10.2. Ecological Effects 

Table 15 and Table 16 identify ecological effects 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. Rationale for the additional data requested is presented 

below the tables. 

Table 15. Submitted Aquatic Ecological Effects Data for fluazifop-p-butyl or fluazifopbutyl

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications 

Are data 

needed to 

conduct risk 

assessment? 

Current Additional Data Need

 850.1010 Freshwater 

invertebrate 

acute toxicity 

00087489 Acceptable No 

850.1025 

850.1035 

850.1045 

850.1055 

Saltwater 

invertebrate 

acute toxicity 

42543201 Acceptable No 

41900601 Supplemental 

 

 850.1075 Freshwater fish 

acute toxicity 

00087485 Acceptable No 

00131458 Supplemental 

 850.1075 Saltwater fish 

acute toxicity 

00152173 Acceptable No 

 850.1300 Freshwater 

invertebrate 

life cycle 

00093807 Acceptable No 

 850.1350 Saltwater 

invertebrates 

life cycle 

No data N/A Yes See explanation below 

850.1500 Freshwater fish 

life cycle 

N/A N/A No 

 850.1400 Freshwater fish 

early-life stage 

00093808 Supplemental No 

 850.1400 Saltwater fish 

early-life stage 

No data N/A Yes See explanation below 

850.4400 Aquatic plant 

growth: 

vascular plants 

N/A N/A No 

850.4500 Aquatic Plant 

Growth: 

algae 

41900603 

49224403 

Invalid 

In Review 

Yes 

850.4550 Cyanobacteria 

(Anabaena flosaquae)

N/A N/A No 
Page 45 of 78 

Table 16. Submitted Terrestrial Ecological Effects Data for fluazifop-p-butyl

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications 

Are data 

needed for 

risk 

assessment? 

Current Additional Data Need 

 850.2100 Avian oral 

toxicity 

40829201 Acceptable No 

 850.2200 Avian dietary 

toxicity 

00087481 Acceptable No 

40851401 Acceptable 

 850.2300 Avian 

reproduction 

00093801 

00093802 

Supplemental 

Supplemental 

Yes See explanation below 

 850.3020 Honey bee 

acute contact 

toxicity 

00162453 Acceptable No 

850.3030 Honey bee 

residue on 

foliage 

N/A N/A No 

 850.3040 Field testing 

for pollinators

N/A N/A No 

850.4100 Terrestrial 

plant toxicity: 

seedling 

emergence 

49453801 In Review Yes See explanation below 

850.4150 Terrestrial 

plant toxicity: 

vegetative 

vigor 

49453802 In Review Yes See explanation below 

Nonguideline Honeybee 

larval oral 

N/A N/A Yes See explanation below 

Nonguideline Honeybee 

acute adult 

oral 

N/A N/A Yes See explanation below 

Nonguideline Honeybee 

larval chronic 

N/A N/A Yes See explanation below 

Nonguideline Honeybee 

adult chronic 

N/A N/A Yes See explanation below 

At the present time, data are sufficient to support an ecological risk assessment except for 

chronic estuarine/marine fish and invertebrate studies, terrestrial and aquatic plant toxicity 

studies, avian reproduction studies and acute/chronic adult oral and larval oral/chronic studies 

with the honeybee. Without these data, assumptions will be made which may be overly 

conservative. 
Page 46 of 78 

Avian Reproduction (850.2300) 

Avian Reproduction studies were submitted and reviewed in 1982. These studies used technical 

fluazifop-butyl, which is now cancelled. There were a number of problems with these studies 

which included deaths in the controls and maximum concentrations (50 ppm in both studies) 

were less than expected maximum field residue exposure levels (in the current case 1.125 lbs 

ai/A x 240 ppm = 270 ppm). The SOP recommends testing at concentrations equal to expected 

field residue levels. Testing should be done with Fluazifop-p acid, since Fluazifop-P-butyl is 

rapidly (less than one day) degraded in soil to fluazifop-p acid, which is much more stable in soil and 

water environments than the parent. 

Honeybee Toxicity (non-guideline)

In keeping with the Agency’s proposed new paradigm for determining potential adverse effects 

to insect pollinators from conventional pesticides (USEPA 2012), additional studies are being 

requested in addition to the acute contact study already submitted. Even though contact to 

fluazifop-p-butyl is slightly toxic to honeybees, an adult acute oral toxicity study (following 

OECD 213) and a larval toxicity study (following OECD 237) are necessary to evaluate the 

potential for fluazifop-p-butyl and/or acid to adversely affect bees and other pollinators through 

other routes of exposure. In addition, adult and larval chronic studies are being requested. 

Several of the treated crop areas may be considered attractive to honey bees and this is a 

systemic chemical that is transported throughout the plant. Thus, residues may be available to 

pollinators via pollen and/or nectar. 

Terrestrial Plant Toxicity (850.4100 and 850.4150) 

Fluazifop-p-butyl is a post-emergent systemic aryloxyphenoxypropionic herbicide to control 

perennial and annual grass weeds. In general, it has little effect on broad-leaved plants (dicots) 

(Ware and Whitacre 2004). Fluazifop-p-butyl is registered to control monocot plant species and 

there are reported incidents in EFED’s Ecological Incident Information System (EIIS) database 

where crop damage was reported on corn, which is a monocot species. There are no data to 

assess risks to terrestrial plants. Tier I seedling emergence and vegetative vigor studies are 

needed. Testing should be done with Fluazifop-p-butyl which degrades rapidly in soil (under 2 

hrs) into fluazifop-p acid, both toxic components of herbicidal activity. Two studies (vegetative 

vigor and seedling emergence) have been recently submitted and are in review. Preliminary 

results suggest effects to monocots only. 

Estuarine/Marine Fish and Invertebrates (850.1350 and 850.1400) 

No data have been submitted regarding chronic toxicity to estuarine/marine fish or invertebrates. 

Fluazifop is highly acutely toxic to freshwater fish and invertebrates. In addition, use on golf 

courses can occur near estuarine areas. Testing should be done using fluazifop-p acid. 

Aquatic Plant Toxicity (850.4400, 850.4500 & 850.4550) 

Aquatic plant testing is required for any herbicide that has outdoor non-residential terrestrial uses 

that may move off-site by runoff, by drift, or that is applied directly to water. Two aquatic plant 

studies have been submitted and one was deemed invalid. The second study used metabolite X 

and is currently in review. Tier II testing should be done using fluazifop-p acid. 
Page 47 of 78 

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Page 51 of 78 

APPENDIX A: Eco and Fate Bibliography for Fluazifop

122809 Fluzifop p butyl Eco Effects Bibliography 

71-1 Avian Single Dose Oral Toxicity 

MRID Citation Reference 

40829201 Roberts, N. (1985) The Acute Oral Toxicity of Fluazifop-p-butyl to the 

Mallard Duck: Project ID: CTL/P/1375. Unpublished study prepared by 

Huntingdon Research Center. 35 p. 

92068004 Edwards, P. (1990) ICI Americas Inc. Phase 3 Summary of MRID 

40829201. The Acute Toxicity (LD50) of Fluazifop-p-butyl (PP005) to 

the Mallard Duck: Report No. CTL/C/1375; Study No. ICI36BT/841263. 

Prepared by Huntingdon Research Centre. 10 p. 

71-2 Avian Dietary Toxicity 

MRID Citation Reference 

40859401 Roberts, N. (1985) The Subacute Dietary Toxicity of Fluazifop-p-butyl 

to the Bobwhite Quail: Laboratory Project ID CTL/P/1410. Unpublished 

study prepared by Huntingdon Research Center. 35 p. 

41199201 Roberts, N.; Fairley, C.; Anderson, A.; et al. (1987) CTL/C/1379-- The 

Subacute Dietary Toxicity of Fluazifop-P-Buty (sic) to the Mallard 

Duck: HRC Report No. ISN 37BT/841262. Unpublished study 

prepared by Huntingdon Research Centre. 36 p. 

92068005 Edwards, P. (1990) ICI Americas Inc. Phase 3 Summary of MRID 

40859401. The Subacute Dietary Toxicity (LC50) of Fluazifop-p-butyl 

(PP005) to the Bobwhite Quail: Report No. CTL/C/1410; Study No. 

ISN/35BT/ 841280. Prepared by Huntingdon Research Centre. 11 p. 

87481 Ross, D.B.; Roberts, N.L.; Phillips, C.N.K.; et al. (1980) The Subacute Dietary Toxicity (LCI50^) of PP 009 to the Mallard Duck: ISK/ICI 

WL 284/79835. (Unpublished study received Dec 4, 1981 under 

10182-EX-27; prepared by Huntingdon Research Centre, England, 

submitted by ICI Americas, Inc., Wilmington, Del.; CDL: 246386-C)

PP009= fluzifop butyl 

71-4 Avian Reproduction 

93801 Roberts, N.L.; Phillips, C.N.K.; Woodhouse, R.N.; et al. (1981) The 

Effect of Dietary Inclusion of Fluazifop Butyl on Reproduction in the 

Mallard Duck: ISK/ICI 286/8144; CTL/C/1071. Final rept. (Unpublished 

study received Jan 18, 1982 under 10182-66; prepared by Huntingdon 
Page 52 of 78 

Research Centre, England, submitted by ICI Americas, Inc., 

Wilmington, Del.; CDL:070630-B) 

93802 Roberts, N.L.; Phillips, C.N.K.; Almond, R.H.; et al. (1981) Fluazifop 

Butyl: The Effect of Dietary Inclusion on Reproduction in the Bobwhite 

Quail: ISK/ICI 287/81209; CTL/C/1092. Final rept. (Unpublished study 

received Jan 18, 1982 under 10182-66; prepared by Huntingdon 

Research Centre, England, submitted by ICI Americas, Inc., 

Wilmington, Del.; CDL:070630-C) 

81-1 Acute oral toxicity in rats 

MRID Citation Reference 

143669 Southwood, J. (1984) Fluazifop-P- Butyl: 125g/1 EC Formulation: Acute Oral Toxicity 

and Acute Dermal Toxicity Studies: Report No.: CTL/P/1008. Unpublished study 

prepared by Imperial Chemical Industries Plc. 67 p. 

161774 Pritchard, V. (1986) Fluazifop-p-butyl: Acute Oral and Dermal Toxicity of an EC 

Formulation to the Rat: Report No. CTL/P/1428. Unpublished study prepared by 

Imperial Chemical Industries Ltd. 45 p. 

162440 Southwood, J. (1984) R Isomer of Fluazifop-butyl (PP005): Acute Oral and Acute 

Dermal Toxicity Studies: Report No. CTL/P/755: CTL Study Nos. AR3092, CB1504. 

Unpublished study prepared by Industrial Chemical Industries PLC, Central Toxicology 

Laboratory. 67 p. 

40439201 Barber, J. (1987) Fluazifop-P-Butyl/Fomesafen: Acute Oral Toxicity to the Rat of a 

0.75/1.0 lb/US gal Formulation: Rept. No. CTL/P/ 1971. Unpublished study prepared 

by Imperial Chemical Industries, Ltd. 27 p. 

41917902 Keenan, K. (1991) Acute Oral Toxicity Test of Fluazifop-P-butyl/Fenoxaprop-P-ethyl 2-

0.56 EC: Lab Project Number: T-14076. Un- published study prepared by ICI 

Americas, Inc. 33 p. 

42518002 Glaza, S. (1991) Acute Oral Toxicity Study of CC-16799 in Rats: Final Report: Lab 

Project Number: HWI 10907490: 91-53. Unpublished study prepared by Hazleton 

Wisconsin, Inc. 27 p. 

42700801 Keenan, K. (1993) Fluazifop-P-Butyl 4EC: Acute Oral Toxicity Test: Lab Project 

Number: RR 93-017B: T-15910. Unpublished study prepared by Zeneca Ag Products, 

Western Research Center. 38 p. 

42729402 Keenan, K. (1993) Fluazifop-P-Butyl 2EC: Acute Oral Toxicity Test: Lab Project 

Number: T-15914: RR 93-014B. Unpublished study prepared by Zeneca Ag Products. 

30 p. 

42841901 Duerden, L. (1993) Fluazifop-P-butyl: Acute Oral Toxicity to the Rat of A 240g/l ME 

Formulation: Lab Project Number: CTL/P/3942: AR5495. Unpublished study prepared 

by Zeneca Central Toxicology Lab. 37 p. 

43662803 Kuhn, J. (1995) Acute Oral Toxicity Study in Rats: Chemsico Grass & Weed Killer M: 

Final Report: Lab Project Number: 1859-95. Unpublished study prepared by 

Stillmeadow, Inc. 24 p. 

43708503 Wnorowski, G. (1995) Acute Oral Toxicity Limit Test (Rat): Chemsico Grass & Weed 

Killer Z: Lab Project Number: 3547: P320: E50214-1H. Unpublished study prepared by 

Product Safety Labs. 15 p. 
Page 53 of 78 

44036702 Robinson, P. (1996) Twister: Fomesafen/Fenoxaprop/Fluazifop-p-Butyl: Acute (Oral) 

Toxicity Study in Rats of a 130.78/19.22/68.42 g/L ME Formulation: Lab Project 

Number: AR6174: CTL/P/4931. Unpublished study prepared by Zeneca Central 

Toxicology Lab. 73 p. 

45892203 Moore, G. (2003) Acute Oral Toxicity Up and Down Procedure in Rats: Chemsico 

Herbicide Concentrate DFC (Alternate II): Lab Project Number: 13124: P320. 

Unpublished study prepared by Product Safety Labs. 15 p. {OPPTS 870.1100} 

45918903 Merkel, D. (2002) Acute Oral Toxicity Study in Rats--Limit Test: Chemsico Herbicide 

RTU DFC: Lab Project Number: 12138: P320. Unpublished study prepared by Product 

Safety Labs. 15 p. {OPPTS 870.1100} 

92068008 McCall, J. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00162440. R-Isomer 

of Fluazifop-butyl (PP005): Acute Oral Toxicity to the Rat: CTL Report No. CTL/P/755; 

CTL Study No. AR3092. Prepared by ICI Central Toxicology Laboratory. 7 p. 

72-1 Acute Toxicity to Freshwater Fish 

MRID Citation Reference 

40829202 In Review Hill, R. (1985) PP005: Determination of the Acute Toxicity of a 25% 

w/w Formulation to Rainbow Trout (Salmo gairdneri): Project ID: 

BL/B/2525. Unpublished study prepared by Imperial Chemical 

Industries PLC. 21 p. 

40829203 In Review Hill, R. (1985) PP005: Determination of Acute Toxicity of a 25% w/w 

Formulation to Bluegill Sunfish (Lepomis macrochirus): Project ID: 

BL/B/2526. Unpublished study prepared by Imperial Chemical 

Industries PLC. 21 p. 

40829204 In Review Hill, R. (1985) PP005: Determination of Acute Toxicity of a 125 g/l 

Formulation to Rainbow Trout (Salmo gairdneri): Project ID: BL/B2553. 

Unpublished study prepared by Imperial Chemical Industries PLC. 21 

p. 

40829205 

49224402 

In Review 

In Review 

Hill, R. (1985) PP005: Determination of Acute Toxicity of a 125 g/l 

Formulation to Bluegill Sunfish (Lepomis macrochirus): Project ID: 

BL/B-2554. Unpublished study prepare by Imperial Chemical 

Industries PLC. 20 p. 

Sankey, S.; Caunter, J.; Morris, D. (1994) R154719-Acute Toxicity to 

Rainbow Trout (Oncorhynchus mykiss): Final Report. Project 

Number: BL5216/B. Unpublished study prepared by Imperial 

Chemical Industries, Ltd./Zeneca. 20p. 

131458 Hill, R.; Maddock, B.; Comber, M. (1983) Fluazifop-butyl: 

Determination of the Acute Toxicity to Rainbow Trout (Salmo 

gairdneri): Brixham Study No. J371/B; Brixham Report No. BL/B/2244. 

(Unpublished study received Oct 6, 1983 under 10182-67; prepared by 

Imperial Chemical Industries PLC, Eng., submitted by ICI Americas, 

Inc., Wilmington, DE; CDL:251454-C) 

92068006 Treacy, C. (1990) ICI Americas Inc. Phase 3 Summary of MRID 

00131458. Fluazifop-P-butyl (P005): Determination of the Acute 
Page 54 of 78 

Toxicity of the Active Ingredient 93 .7% w/w to Rainbow Trout (Salmo 

gairdneri): Report No. BL/B/2244; Study No. J 371/B. Prepared by ICI 

Brixham Laboratory. 11 p. 

87483 Hill, R.W.; Maddock, B.G.; Harland, B.J. (1981) Determination of the 

Acute Toxicity of PP009 to Rainbow Trout (Salmo gairdneri): 

BL/B/2036. Includes undated method entitled: Determination of PP 

009 in water samples from fish bioassay studies. (Unpublished study 

received Dec 4, 1981 under 10182-EX-27; pre- pared by Imperial 

Chemical Industries, Ltd., England, submitted by ICI Americas, Inc., 

Wilmington, Del.; CDL:246386-E) PP009= fluizifop butyl 

72-2 Acute Toxicity to Freshwater Invertebrates 

MRID Citation Reference 

162451 Hamer, M.; Hill, I. (1983) PP005: Toxicity of the Technical Material and 

Formulations JF8906 and JF8908 to First Instar Daphnia magna: 

Report Series: RJ 0312B. Unpublished study prepared by ICI Plant 

Protection Div., Jealotts Hill Research Station. 15 p. 

Three different test materials 

162452 Hamer, M.; Hill, I. (1983) Fluazifop: Toxicity of Different R:S 

Enantiomer Ratios to First Instar Daphnia magna: Report Series: RJ 

0315B. Unpublished study prepared by ICI Plant Protection Div., 

Jealotts Hill Research Station. 17 p. 

40829206 

49224401 

In Review 

In Review 

Farrelly, E.; Homer, M.; Hill, I. (1984) PP005: Toxicity of Formulations 

GFU 239A and GFU 324A to First Instar Daphnia magna: Project ID: 

RJ0376B. Unpublished study prepared by ICI Plant Protection Div. 16 

p. 

Hill, I.;Arnold, J.; Hamer, M. (1982) Fluazifop-P-Butyl 5-Trifluormethyl2-pyridone-Toxicity to First Instar Daphnia manga:Final Report. Project 

number RJ0252B. Unpublished study prepared by Imperial Chemical 

Industries. 12p. 

92068007 Hamer, M. (1990) ICI Americas Inc. Phase 3 Summary of MRID 

00162451. Toxicity of the Technical Material and FormulationsIF8-906 

and JF8909 to First Instar Daphnia magna: Report No. RJ0312; Study 

No. PP005/CN/01. Prepared by ICI Agrochemicals. 16 p. 

92068042 Hamer, M. (1990) ICI Americas Inc. Phase 3 Summary of MRID 

00162452. Toxicity of Different R:S Enantiomer Ratios to First Instar 

Daphna [sic] magna: Report No. RJ0315B; Study No. PP004/CN/01. 

Prepared by ICI Agrochemicals. 17 p. 

72-3 Acute Toxicity to Estuarine/Marine Organisms 

MRID Citation Reference 

41900601 Dionne, E. (1991) (Fluazifop-p-Butyl)-Acute Toxicity to Eastern Oyster 

(Crassostrea virginica) Under Flow-Through Conditions: Lab Project 
Page 55 of 78 

Number: 91-4-3746: 1828.1190.6107.504. Unpublished study 

prepared by Springborn Laboratories, Inc. 57 p. 

42543201 Willams, T.; Tapp, J.; Sankey, S. et al. (1991) Fluazifop-P-Butyl: Acute 

Toxicity to Mysid Shrimp (Mysidopsis bahia): Lab Project Number: 

BL4295/B. Unpublished study prepared by ICI Group Environmental 

Lab. 18 p. 

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

MRID Citation Reference 

41900602 Tapp, J.; Maddock, B.; Caunter, J.; et al. (1991) (Fluazifop-p-But- yl)-

Chronic Toxicity to Fathead Minnow (Pimephales promelas) Embryos 

and Larvae: Lab Project Number: BL/4008/B: T820/A (FT95/ 90). 

Unpublished study prepared by ICI PLC Group Environmental 

Laboratory. 57 p. 

93807 Edwards, P.J.; Brown, S.M.; Hamer, M.J.; et al. (1981) Fluazifop- butyl: 

21 Day Daphnia magna Life-cycle Study: Report Series RJ 0209B. 

Final rept. (Unpublished study received Jan 18, 1982 under 10182-66; 

submitted by ICI Americas, Inc., Wilmington, Del.; CDL:070630-H) 

122-1 Seed Germination/Seedline Emergence and Vegetable Vigor 

MRID Citation Reference 

41555201 Rea, D.; Mannion, S.; Martin, E.; et al. (1989) PP005: Effects on the 

Plants in the Weed Science and Plant Growth Regulator Screens of 

the Biological Group: Lab Project Number: RJ 0501B. Unpublished 

study prepared by ICI Agrochemicals, Jealott's Hill. 23 p. 

93811 Poole, N.J.; Collins, D.J.; Dalziel, J.; et al. (1981) Fluazifop- butyl, 

Fluazifop and 5-Trifluoromethyl-pyrid-2-one: Effects on the Arthropods, 

Nematodes, Micro-organisms and Plants Used in the Pesticide 

Screens: Report Series RJ 0214 B. Final rept. (Unpublished study 

received Jan 18, 1982 under 10182-66; sub- mitted by ICI Americas, 

Inc., Wilmington, Del.; CDL:070631-D) 

122-2 Aquatic plant growth 

MRID Citation Reference 

41900603 Smyth, D.; Tapp, J.; Sankey, S.; et al. (1985) Fluazifopp-Butyl: Toxicity to the Green Alga Selenastrum 

capricornutum: Lab Project Number: BL4040/B: N280/B 

(FT11/85). Unpublished study prepared by ICI PLC 

Group Environmental Laboratory. 22 p.
Page 56 of 78 

49224403 

In review 

Kent, S.; Sankey, S.; Smyth, D. (1994) Toxicity to the 

Green Alga Selenastrum capricornutum: Final Report. 

Project Number: BL5205/B. Unpublished study prepared 

by Imperial Chemical Industries, Ltd./Zeneca. 24p. 

 

141-1 Honey bee acute contact 

MRID Citation Reference 

162453 Collins, I.; Gough, H.; Wilkinson, W. (1984) PP005: Acute Contact and 

Oral Toxicity to Honey Bees (Apis melifera): Report Series: RJ 0345B. 

Unpublished study prepared by ICI Plant Protection Div., Jealotts Hill 

Research Station. 19 p. 

92068017 Lewis, G. (1990) ICI Americas Inc. Phase 3 Summary of MRID 

00162453. PP005: Acute Contact and Oral Toxicity to Honey Bees 

(Apis Mellifera): Report No. RJ0345B; Study No. PP005/CM/01. 

Prepared by ICI Agrochemicals. 13 p. 

Non Guideline Selections 

147633 ICI Americas Inc. (1984) Toxicology to Fish and Wildlife [with PP005 

1E and 2E Herbicides]. Unpublished study. 6 p. 

Fate/Chemistry Bibliography 

161-1 Hydrolysis 

MRID Citation Reference 

41598001 McCarron, E.; Heath, J. (1989) Fluazifop-P-Butyl: Hydrolysis in Sterile 

Aqueous Solution: Lab Project Number: 89JH132. Unpublished study 

prepared by ICI Agrochemicals. 57 p. 

46190601 Goodyear, A. (1995) (Carbon 14)-Fluazifop-P: Hydrolysis in Sterile 

Aqueous Solution: Final Report. Project Number: 38/187/1015, 38/187. 

Unpublished study prepared by Hazleton Uk. 78 p. 

161-2 Photodegradation-water 

MRID Citation Reference 
Page 57 of 78 

42543202 

49188701 In Review 

Jessup, K.; Embury, G.; Leahey, J. (1991) Fluazifop-P-Butyl: 

Photodegradation in Aqueous Solution at pH 5: Lab Project Number: 

RJ0992B. Unpublished study prepared by ICI Agrochemicals. 74 p. 

Graham, R., T. Fletcher, and J. Gilbert. (2013) Fluazifop-P-Butyl. 

R156172 – Photodegradation of [14C]Fluazifop-P, R156172, in Sterile 

Aqueous Solution. Final Report. Unpublished study performed by 

Smithers Vincient (ESG) Ltd, Harrogate, UK, and Convance 

Laboratories Ltd, Harrogate and Alnwick, UK; sponsored and 

submitted by Syngenta Crop Protection, LLC. 

161-3 Photodegradation-soil 

MRID Citation Reference 

41598002 French, D.; Matharu, K. (1989) Fluazifop-P-Butyl: Photodegradation on 

a Soil Surface: Lab Project Number: 89JH269. Unpublished study 

prepared by ICI Agrochemicals. 99 p. 

162 -1 Aerobic Soil Metabolism 

87493 

ACC 246387 

 Harvey, B.R., J. Vincent, R. Mistry and D.J. Arnold (1981) 

Fluazifopbutyl: Degradation in Soil. Unpublished Study Performed by 

ICI Agrochemicals, Bracknell, UK and Submitted by ICI Americas Inc., 

Wilmington, DE. 

162455 

ACC 252853 

 Bewick, D. (1983) Fluazifop-butyl: Fate of the Separate R and S-- 

Enantiomers in Soil: Report Series: RJ 0306B. Unpublished study 

prepared by ICI Plant Protection Div., Jealotts Hill Research Station. 

21 p. 

87493 

summary 

92067032 

 Leahey, J. (1990) ICI Americas Inc. Phase 3 Summary of MRID 

00087493. Fluazifop-butyl: Degradation in Soil and a Comparison of 

the Microflora and Physicochemical Properties of Soils Used in UK 

Laboratory Studies with those of USA Soils: Report Nos. RJ0197B and 

RJ0429B; Study Nos. PP009AD02 and PP000CK10. Prepared by ICI 

Agrochemicals. 32 p. 

162454 

ACC 252853 

 Bewick, D. (1982) Fluazifop: Stereochemistry of Residues Derived 

from the Hydrolysis of Fluazifop-butyl in Soil: Report Series: RJ 0270B. 

Unpublished study prepared by ICI Plant Protection Div. 28 p. 

46190602 Goodyear, A. (1998) (Carbon 14)-Fluazifop-P: Soil Degradation at 20 

(Degrees) C: Final Report. Project Number: 38/200/D2142, 38/200. 

Unpublished study prepared by Covance Laboratories, Ltd. 64 p. 

162-2 Anaerobic Soil Metabolism 

87493 Harvey, B.R.; Vincent, J.; Mistry, R.; et al. (1981) Fluazifop- butyl: 

Degradation in Soil: Report Series RJ 0197B. (Unpublished study 

received Dec 4, 1981 under 10182-EX-27; prepared by Imperial 
Page 58 of 78 

Chemical Industries, Ltd., England, submitted by ICI Americas, Inc., 

Wilmington, Del.; CDL:246387-E) 

92067033 Leahey, J.P. (1990b) Phase 3 Summary of MRID 87493. 

Fluazifopbutyl: Degradation in Soil and a Comparison of the Microflora 

and Physicochemical Properties of Soils used in UK Laboratory 

Studies with those of USA Soils. Report No. RJ0197B and RJ0429B. 

Anaerobic Soil Metabolism. Study No. PP009/AD0Z and PP000CK10. 

Unpublished Summary Prepared by ICI Agrochemicals, Bracknell, UK 

and Submitted by ICI America, Inc., Wilmington, DE. 

162-4 Aerobic Aquatic Metabolism 

46190605 Purser, D. (1988) (Carbon 14)-Fluazifop-p-Butyl: Degradation and 

Retention in Water Sediment Systems: Fluazifop-P-Butyl: Final Report. 

Project Number: 38/232/D2142, 38/232. Unpublished study prepared 

by Covance Laboratories, Ltd. 130 p. 

163-1 Leach/adsorp/desorption 

MRID Citation Reference 

41900604 Lane, M.; Vaughn, P. (1991) Fluazifop-p-Butyl: Adsorption and Desorption of Two Soil Metabolites, Fluazifop and R154719: Lab Project 

Number: RJ0967B. Unpublished study prepared by ICI Agrochemicals. 50 p. 

46190603 Goodyear, A. (1998) (Carbon 14)-Fluazifop-P: Adsorption/ Desorption 

in Soil: Final Report. Project Number: 38/197/D2142, 38/197. 

Unpublished study prepared by Covance Laboratories, Ltd. 61 p. 

46190604 

49193101 In Review 

Ziegler, D. (1988) Adsorption of Fluazifop-Butyl to Loamy Sand, Loam, 

Silty Clay Loam, and Silt Loam: Fluazifop-p-Butyl: Final Report. Project 

Number: 1086. Unpublished study prepared by Analytical 

Development Corp., Inc. 66 p. 

Lane, M.C.G. and D. Rowe. (1998) Fluazifop-P-Butyl - Adsorption and 

Desorption Properties of a Soil Metabolite Compound X (R154719) in 

Four Soils. Final Report. Unpublished study performed by ZENECA 

Agrochemicals, Jealott’s Hill Research Station, Berkshire, UK 

164-1 Terrestrial field dissipation 

MRID Citation Reference 

41598003 Wiebe, L. (1989) Fusilade 2000: Field Dissipation Study for Terrestrial Uses: Visalia, California, 1989: Lab Project Number: FUSI -89-

SD-01: US02-89-211: 89-066B. Unpublished study prepared by ICI 

Americas Inc. 129 p. 
Page 59 of 78 

41598004 Wiebe, L. (1989) Fusilade 2000: Field Dissipation Study for Terrestrial Uses Porterville, California, 1989: Lab Project Number: FUSI-89-

SD-01: 94CA-89-212: RR 89-067B. Unpublished study pre- pared by 

ICI Americas Inc. 125 p. 

41900605 Wiebe, L. (1990) Fusilade 2000: Field Dissipation Study for Terrestrial Uses Visalia, California, 1989-1990: Lab Project Number: RR 90-

337B. Unpublished study prepared by ICI Americas Inc. 188 p. 

41900606 Wiebe, L. (1990) Fusilade 2000: Field Dissipation Study for Terrestrial Uses Porterville, California, 1989-1990: Lab Project Numb- er: RR 

90-338B. Unpublished study prepared by ICI Americas Inc. 177 p. 

87495 Ussary, J.P.; Koubek, K.G.; Theodorakis, S.K.; et al. (1981) Fluazifopbutyl Dissipation in Soils: Report Series TMU0657/B. (Unpublished 

study received Dec 4, 1981 under 10182-EX-27; sub- mitted by ICI 

Americas, Inc., Wilmington, Del.; CDL:246387-G) 

92076034 

49193104 In Review 

Iwata, Y. (1990) Phase 3 Summary of MRID 87495. Fusilade Field 

Dissipation Study for Terrestrial Uses. Unpublished Summary 

Submitted by ICI Amreicas Inc., Richmond, CA. 

Wiepke, T., Jacobson, B., Hagan, M., and Bertrand, N. (2013) 

Fluazifop-P-butyl – Dissipation of Fluazifop-P-Butyl EC (240) in Soil 

Under Soybean Production Conditions and Agricultural Fallow/NonCrop Land Use Conditions in the Southeastern United States. Final 

Report. Unpublished study performed by Syngenta Crop Protection, 

LLC. 

 165-4 Fish Bioaccumulation 

No MRID Bull, J.M., E.A. Curl and I.R. Hill (1981) Fluzifopbutyl: Accumulation in 

Bluegill Sunfish in a Flow-Through System. Unpublished Study 

Performed by ICI Agrochemicals, Bracknell, UK and Submitted by ICI 

Americas, Inc. Wilmington, DE. 

93976 ? OPPIN shows different Citation for this MRID 

92067035 Hamer, M.J. (1990) Summary of MRID 00093976. Fluazifopbutyl: 

Accumulation in Bluegill Sunfish in a Flow-Through System. 

Unpublished Summary Document Prepared by ICI Agrochemicals, 

Bracknell, UK and Submitted by ICI Americas Inc., Wilmington, DE. 

166-1 Ground water-small prospective 

MRID Citation Reference 

46190605 Purser, D. (1988) (Carbon 14)-Fluazifop-p-Butyl: Degradation and Retention in Water 

Sediment Systems: Fluazifop-P-Butyl: Final Report. Project Number: 38/232/D2142, 

38/232. Unpublished study prepared by Covance Laboratories, Ltd. 130 p. 

171-4B Residue Analytical Methods 
Page 60 of 78 

MRID Citation Reference 

40361102 French, D.; Leahey, J. (1987) Fluazifop-P-butyl: Determination of Radioactive 

Residues in Grapes from a Vine Treated with 2 Basal Applications of [Carbon 14]-

Fluazifop-P-butyl: Lab. Proj. ID RJ0569B. Unpublished study prepared by ICI Plant 

Protection Div., Jealott's Hill Research Station. 21 p. 

40361103 Harradine, K. (1984) The Detection of Residues of Total Fluazifop (Fluazifop-Butyl, 

Fluazifop and Conjugate Esters): In Crops - A Nuclear Magnetic Resonance 

Spectroscopic Method: Residue Analytical Method No. 83. Unpublished study 

prepared by ICI Plant Protection Div., Jealott's Hill Research Station. 15 p. 

40704805 Watford, S.; Francis, P. (1987) Supplement ... Fluazifop-p-butyl: Fluazifop Residues in 

Plum and Prune Samples (1986): Laboratory Project ID: TMU3311/B. Unpublished 

study prepared by ICI Americas Inc. 6 p. 

40831307 Hayward, G. (1987) The Determination of Residues of Total Fluazifop (Fluazifop-pButyl, Fluazifop and Conjugate Esters) in Oily Crops: Project ID: Analytical Method No. 

122. Unpublished study prepared by ICI Plant Protection Div. 22 p. 

41041501 Malhorta, R. (1989) Analysis of Fluazifop-p-butyl and Fluazifop Residues by Analytical 

Methods in FDA Pesticide Manual Vol.1: HAS A030.001. Unpublished study prepared 

by Huntington Analytical Services. 146 p. 

92068020 Bussey, R. (1990) ICI Americas Inc. Phase 3 Summary of MRID 40831303 and 

Related MRIDs 40831305, 40831304, 00152494, 00151494, 40361110, 40704805. 

FUSILADE Residue Analytical Method: Laboratory No. RR-90-098B. Prepared by ICI 

Agricultural Experiment Station. 14 p. 

92068021 Atreya, N. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00093843. The 

Determination of Residues of Fluazifop-P-butyl and Fluazifop Free and Lipophilic 

Conjugates in Milk and Bovine Tissues - A high Pressure liquid Chromatography and 

Gas Chromatography - Mass Spectrometry Method: Report No. Plant Protection 

Division Analytical Method (PPRAM) No. 61; Study No. PP009BA01. Prepared by ICI 

Agrochemicals. 16 p. 

92068040 Atreya, N. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00093845. The 

Determination of Residues of Fluazifop-butyl (PP009): Fluazifop and Conjugate Esters 

of Fluazifop in Eggs and Chicken Tissue: Plant Protection Division Residue Analytical 

Method (PPRAM) No. 58. Prepared by ICI Agrochemicals. 17 p. 

92068041 Atreya, N. (1990) ICI Americas Inc. Phase 3 Summary of MRID 40831310. The 

Determination of Residues of 5-Trifluoromethyl-2- pyridone (Reference X) in Crops - A 

Nuclear Magnetic Resonance Spectroscopic Method: Plant Protection Division 

Residue Analytical Method (PPRAM) No. 103. Prepared by ICI Agrochemicals. 12 p. 

92068043 

49193107 

49193106 

Bussey, R. (1990) ICI Americas Inc. Phase 3 Reformat of MRID 40831303 and 

Related MRIDs 40831304, 40831305, 40831307, 00152494, 00151494, 40361110, 

40704805. FUSILADE Residue Analytical Method: Laboratory Study ID No. RR 90-

103B. Prepared by ICI Americas, Inc. 120 p. 

Huang, S.-B. (2010) Fluazifop-P-Butyl: GRM044.03A - Analytical Method for the 

Determination of Fluazifop-P-Butyl (R154875; PP5), Fluazifop-P-Acid (R156172) and 

Compound X (R154719; CGA142110) in Soil Using Liquid Chromatography-Tandem 

Mass Spectrometry (LC-MS/MS): Analytical Method Amendment. Prepared by 

Syngenta Crop Protection, LLC. 

Perez, R., J. L. Schmitt. (2013) Fluazifop-P-Butyl: Fluazifop-P-Butyl - Independent 

Laboratory Validation of Analytical Method (GRM044.03A) for the Determination of 

Fluazifop-P-Butyl (R154875; PP5), Fluazifop-P-Acid (R156172), Compound X 
Page 61 of 78 

(R154719; CGA142110) in Soil Using Liquid Chromatography-Tandem Mass 

Spectrometry (LC-MS/MS): Final Report. Prepared by ADPEN Laboratories, Inc. 

171-4C Magnitude of the Residue [by commodity] 

MRID Citation Reference 

151494 ICI Americas, Inc. (1985) Fusilade 2000 1E Herbicide (Containing Fluazifop-P-Butyl): 

Amendment of Tolerance Petition for Onions: Residue Chemistry: [Includes Response 

to EPA's Commnents and Comparative Study of Residues in Onions with Fluazifop-PButyl/ Fluzaifop-Butyl]. Unpublished compilation. 65 p. 

162047 Morgan, J.; Crook, S. (1986) Fluazifop-p-butyl: Residues in Onions from Trials Carried 

out in the U.S.A. during 1984: Report Series M4266B. Unpublished study prepared by 

ICI Plant Protection Div. 29 p. 

162447 ICI Americas, Inc. (1984) Residue Chemistry: Registration Applica- tion for Cotton and 

Soybeans: PP005 2E Herbicide (Containing Fluazifop-P-butyl). Unpublished 

compilation. 70 p. 

40140401 Hayward, G. (1987) Fluazifop-P-Butyl: Storage Stability of Residues in Deep Frozen 

Onion Samples: [Interim Report]: Lab. Proj. ID M4429B. Unpublished study prepared 

by ICI Agricultural Experiment Station. 13 p. 

40294002 Hayward, G. (1987) Fluazifop-p-butyl (Reference X): Storage Stability of Residues in 

Deep Frozen Onion Samples: Laboratory Project ID: M4544B. Unpublished study 

prepared by ICI Plant Protection Division. 14 p. 

40361104 Trumbo, K.; Francis, P. (1986) Fluazifop-butyl: Storage Stability of Residues in Deep 

Frozen Tomato Samples: Lab. Proj. ID TMU 3079. Unpublished study prepared by ICI 

Americas Inc. 12 p. 

40361106 Watford, S.; Francis, P. (1986) Residue Levels of Fluazifop in Apples: Lab. Proj. ID 

TMU3119/B. Unpublished study prepared by ICI Americas Inc. 16 p. 

40361107 Watford, S.; Francis, P. (1987) Fluazifop-P-butyl: Fluazifop Residues in Apple 

Samples: Lab. Proj. ID TMU3291/B. Unpublished study prepared by ICI Americas Inc. 

35 p. 

40361108 Watford, S.; Francis, P. (1987) Fluazifop-P-butyl: Residue Levels of Fluazifop in 

Cherries (PP005) 1986: Lab. Proj. ID TMU3181/B. Unpublished study prepared by ICI 

Americas Inc. 43 p. 

40361109 Watford, S.; Francis, P. (1987) Fluazifop-P-butyl: Residue Levels of Fluazifop in 

Peaches (PP005) 1986: Lab. Proj. ID TMU3168/B. Unpublished study prepared by ICI 

Americas Inc. 38 p. 

40361110 Watford, S.; Francis, P. (1987) Fluazifop-P-butyl: Fluazifop Residues in Plum and 

Prune Samples (1986): Lab. Proj. ID TMU3311/B. Unpublished study prepared by ICI 

Americas Inc. 48 p. 

40361111 Watford, S.; Francis, P. (1987) Fluazifop-P-butyl: Fluazifop Residues in Pecans 

(1985): Lab. Proj. ID TMU3251/B. Unpublished study prepared by ICI Americas Inc. 16 

p. 

40361112 Watford, S.; Francis, P. (1987) Fluazifop-P-butyl: Fluazifop-P- butyl Residues in Grape 

Samples: Lab. Proj. ID TMU3330/B. Unpublished study prepared by ICI Americas Inc. 

26 p. 
Page 62 of 78 

40361113 Watford, S.; Francis, P. (1987) Fluazifop-P-butyl: Residue Levels of Fluazifop on 

Grapes (1986): Lab. Proj. ID TMU3144/B. Unpublished study prepared by ICI 

Americas Inc. 45 p. 

40693102 French, D.; Brown, P.; Leahey, J. (1987) Fluazifop-P-Butyl: Quantification and 

Characterization of Radioactive Residues in Celery: Proj. ID RJ0590B. Unpublished 

study prepared by Imperial Chemi- cal Industries, Jealott's Hill Research Station. 75 p. 

40693103 Trumbo, R.; Francis, P. (1986) Fluazifop-P-Butyl: Residues of Fluazifop on Celery: 

Proj. ID TMU3077/B. Unpublished study prepared by ICI Americas Inc. 15 p. 

40693104 Watford, S.; Francis, P. (1988) Fluazifop-P-Butyl: Fluazifop and Reference X Residues 

in Celery (1986): Proj. ID TMU3418/B. Un- published study prepared by ICI Americas 

Inc. 86 p. 

40693105 Plyler, S.; Francis, P. (1986) Fluazifop-Butyl: Residues of Fluazifop on Lettuce: Proj. 

ID TMU3005/B. Unpublished study prepared by ICI Americas Inc. 19 p. 

40693106 Watford, S.; Francis, P. (1988) Fluazifop-P-Butyl: Fluazifop and Reference X Residues 

in Lettuce (1986): Proj. ID TMU3418/B. Unpublished study prepared by ICI Americas 

Inc. 52 p. 

40831301 Kaminski, B. (1988) Residue Chemistry Data Overview and Summary: (Fusilade 2000 

4E Herbicide). Unpublished study prepared by ICI Americas Inc. 95 p. 

40831302 Koubek, K. (1984) Fluazifop Residues in Peanuts: Supplement to Previously 

Submitted Data, EPA Accession No. 072889, Ref. 11D: Project ID: TMU 1196/B 

Revised. Unpublished study prepared by ICI Americas Inc. 88 p. 

40831306 Francis, P.; Plyler, S. (1986) Fluazifop-p-Butyl: A Comparison of the Level of Residues 

Found in Peanuts from Trials Conducted in 1984: Project ID: TMU 1978. Unpublished 

study prepared by ICI Americas Inc. 19 p. 

40831308 Hayward, G. (1988) Fluazifop-p-Butyl and Reference X, Residues in Peanuts from 

Trials in the USA During 1986: Project ID: M 4600B. Unpublished study prepared by 

ICI Plant Protection Div. 18 p. 

40831309 Hayward, G. (1988) Fluazifop-p-Butyl (Reference X): Storage Stability of Residues in 

Deep Frozen Peanut Kernel Samples: Project ID: M4723B. Unpublished study 

prepared by ICI Plant Protection Div. 14 p. 

41007602 Roper, E.; Francis, P. (1988) Fluazifop-P-Butyl: Residues of Fluizafop (sic) in 

Sugarcane Following Spot Applications of Fusilade 2000: Proj. ID TMU 3310/B. 

Unpublished study prepared by ICI Americas Inc. 32 p. 

41108001 Baron, J. (1989) Fluazifop: Magnitude of Residue on Asparagus--MI Study: IR-4 PR 

No. 3944. Unpublished study prepared by IR-4 Northcentral Analytical Laboratory, 

Michigan State Univ. 34 p. 

41165101 Francis, P. (1989) Fluazifop Residues in Peanuts: Supplement to Previously 

Submitted Data, EPA MRID No. 40831302. Unpublished study prepared by ICI 

Americas Inc. 9 p. 

41373702 Hayward, G. (1988) Fluazifop-p-butyl and Reference X: Storage Stability of Residues 

in Deep Frozen Onion Samples: Lab Project ID M4843B. Unpublished study prepared 

by ICI Agrochemicals. 12 p. 

41373703 Hayward, G. (1988) Fluazifop-p-butyl (Reference X): Storage Stability of Residues in 

Deep Frozen Apples, Lettuce and Soybean Samples: Laboratory Project ID M4842B. 

Unpublished study pre- pared by ICI Agrochemicals. 17 p. 

41373704 Hayward, G. (1988) Fluazifop-p-butyl and Reference X: Storage Stability of Residues 

in Deep Frozen Peanut Kernel Samples: Lab Project ID: M4841B. Unpublished study 

prepared by ICI Agrochemicals. 14 p. 
Page 63 of 78 

41373705 Francis, P. (1989) Fusilade 2000 (Fluazifop-p-butyl)--Magnitude of the Residue Study 

on Citrus: Lab Project Number: 005-86-05: RR 89-051B. Unpublished study prepared 

by ICI Americas, Inc. 135 p. 

41373706 Francis, P. (1989) Fusilade 2000 (Fluazifop-p-butyl)--Magnitude of the Residue on 

Processed Orange Products: Lab Project ID: 005-86-07: RR 89-052B. Unpublished 

study prepared by ICI Americas, Inc. 55 p. 

92068022 Atreya, N. (1990) ICI Americas Inc. Phase 3 Summary of MRID 40294002 and Related 

MRIDs 40140401, 41373702, 41373703, 40831309. Fluazifop-P-butyl: Storage 

Stability of Residues in Deep Frozen Crop Samples: Report Nos. M4429B, M4843B, 

M4723B, M4841B and M4842B. Prepared by ICI Agricultural Experiment Station. 9 p. 

92068023 Baron, J. (1990) ICI Americas Inc. Phase 3 Summary of MRID 40355101. Fluazifop: 

Magnitude of the Residue in or on Asparagus: Project No. 2201; Pesticide Petition 

7E3565. Prepared by Interregional Research Project No. 4. 8 p. 

92068024 Atreya, N. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00152494. FluazifopP-butyl: Residues in Carrots and Sugarbeet from Trials Carried out in the USA During 

1983 and 1984: Report No. M44041B: Study No. PP005B026. Prepared by ICI 

Agrochemicals. 9 p. 

92068025 Baron, J. (1990) ICI Americas Inc. Phase 3 Summary of MRID 40725701. Fluazifop - 

Magnitude of the Residue on Coffee: Project No. 3432: Pesticide Petition 8E 3661. 

Prepared by University of HawaiI. 11 p. 

92068026 Riggle, B. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00162447 and Related 

MRIDs 00093841, 00116676, 00131452, 00162447. FUSILADE Magnitude of the 

Residue in or on Cotton Seed: ID No. RR-90-075B. Prepared by ICI Americas, Inc. 10 

p. 

92068027 Baron, J. (1990) ICI Americas Inc. Phase 3 Summary of MRID 40341601 and Related 

MRIDs 41148301. Fluazifop: Magnitude of the Residue on Endive: Project No. 3462. 

Prepared by USDA-ARS Southeast Watershed Res. Lab. 10 p. 

92068028 Riggle, B. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00151494 and Related 

MRIDs 00161922. FUSILADE Magnitude of the Residue in or on Bulb Onions: Project 

No. RR-90-052B. Prepared by ICI Americas Inc. 10 p. 

92068029 Atreya, N. (1990) ICI Americas Inc. Phase 3 Summary of MRID 40294003 and Related 

MRIDs 00162047. Residues in Onions from Trials Carried Out in the USA During 

1984: Report Nos. M4266B and M4545B; Study Nos PP005B072 and PP005B121. 

Prepared by ICI Agricultural Experiment Station. 9 p. 

92068030 Riggle, D. (1990) ICI Americas Inc. Phase 3 Summary of MRID 40361111. FUSILADE 

Magnitude of the Residue in or on Pecans: Laboratory ID No. RR/90/057B. Prepared 

by ICI Americas, Inc. 8 p. 

92068031 Baron, J. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00157191 and Related 

MRIDs 00157192, 00157193. Fluazifop - Magnitude of the Residue on Tabasco 

Pepper: IR-4; Project No. 2947 and Petition 6E 3384. Prepared by INTERREGIONAL 

RESEARCH PROJECT NO. 4. 8 p. 

92068032 Baron, J. (1990) ICI Americas Inc. Phase 3 Summary of MRID 40241901. Fluazifop: 

Magnitude of the Residue on Rhubarb: Project No. 2073. Prepared by N.Y. State AgrI. 

Experiment Station. 8 p. 

92068033 Riggle, B. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00162447 and Related 

MRIDs 00093840, 00116676, 00131452, 00162447. FUSILADE Magnitude of the 

Residue in or on Soybeans: Laboratory Study ID RR 90-051B. Prepared by ICI 

Americas, Inc. 11 p. 
Page 64 of 78 

92068034 Riggle, B. (1990) ICI Americas Inc. Phase 3 Summary of MRID 40704805 and Related 

MRIDs 40361110. FUSILADE Magnitude of the Residue in or on Plums and Prunes: 

Laboratory ID No. RR 90-058B. Prepared by ICI Americas, Inc. 9 p. 

92068035 Riggle, B. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00137763. FUSILADE 

Magnitude of the Residue on Carrots: Laboratory ID No. RR-90-030B. Prepared by ICI 

Americas, Inc. 11 p. 

92068036 Baron, J. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00144014 and Related 

MRIDs 00164500. Fluazifop: Magnitude of the Residue on Sweet Potato: Study ID No. 

2328 and Pesticide Petition 4E3100. Prepared by INTERREGIONAL RESEARCH 

PROJECT NO. 4. 9 p. 

92068037 Baron, J. (1990) ICI Americas Inc. Phase 3 Summary of MRID 41018001. Fluazifop: 

Magnitude of the Residue in or on Macadamia Nut: Study ID IR-4, Project No. 3431 

and Pesticide Petition No. 9E3737. Prepared by INTERREGIONAL RESEARCH 

PROJECT NO. 4. 11 p. 

92068038 Riggle, B. (1990) ICI Americas Inc. Phase 3 Summary of MRID 40361108 and Related 

MRIDs 40704803. FUSILADE Magnitude of the Residue in or on Cherries: Laboratory 

Study ID No. RR 90-060B. Prepared by ICI Americas, Inc. 8 p. 

92068039 

49193108 

49193105 

Riggle, B. (1990) ICI Americas Inc. Phase 3 Summary of MRID 40361109 and Related 

MRIDs 40704804. FUSILADE Magnitude of the Residue in or on Peaches: Laboratory 

ID No. RR-90-059B. Prepared by ICI Americas, Inc. 8 p. 

Huang, S.-B. 2012. Fluazifop-P-Butyl: Fluazifop-P-Butyl – Residue Method for the 

Determination of Fluazifop-P-Butyl (R154875; PP5), Fluazifop-P-Acid (R156172), 

Compound IV (R150397; CGA181847) and Compound X (R154719; CGA142110) in 

Water: Analytical Method. Prepared by Syngenta Crop Protection, LLC. 

Perez, R., J. L. Schmitt. 2013. Fluazifop-P-Butyl: Independent Laboratory Validation of 

Residue Method (GRM044.04A) for the Determination of Fluazifop-P-Butyl (R154875; 

PP5), Fluazifop-P-Acid (R156172), Compound IV (R150397; CGA181847) and 

Compound X (R154719; CGA142110) in Water: Final Report. Report prepared by 

ADPEN Laboratories, Inc. 

171-4A2 Nature of the Residue in Plants 

MRID Citation Reference 

92068018 Leahey, J. (1990) ICI Americas Inc. Phase 3 Summary of MRID 40693102. FluazifopP-butyl: Quantitation and Characterization of Radioactive Residues in Celery: Report 

No. RJ0590B; Study No. PP005AC03. Prepared by ICI Agrochemicals. 15 p. 

92068019 Leahey, J. (1990) ICI Americas Inc. Phase 3 Summary of MRID 40361102. FluazifopP-butyl: Determination of Radioactive Residues in Grapes From a Vine Treated with 2 

Basal Applications of Carbon-14- Fluazifop-P-butyl: Report No. RJ0569B; Study No. 

PP005AC02. Prepared by ICI Agrochemicals. 11 p. 
Page 65 of 78 

APPENDIX B: ECOLOGICAL TOXICITY DATA 

Summary of Toxicity Data for Fluazifop-p-butyl 

Plant Data 

Green Alga, Static, Metabolite X 72 hr EC50 340 ppm Biomass 

NOAEC 100 ppm/LOAEC 200 ppm 

49224403, 1994 

IN REVIEW 

Terrestrial Invertebrate Data 

Honeybee (Apis mellifera), Adult, O, / 

Fluazifop-butyl, Tech% ai 

24 hr LD50 153.70686 ug/Bee ae (180 

ug/Bee ai) slope = NA 

00093809, 1979 

/Acceptable 

Honey bee (Apis mellifera), Adult, O, / 

Fluazifop-butyl formulation, 25EC% ai 

24 hr LD50 166.515765 ug/Bee ae (195 

ug/Bee ai) slope = NA 

00093809, 1979 

/Acceptable 

Honey bee (Apis mellifera), Adult, C, / 

Fluazifop-butyl, Tech% ai 

24 hr LD50 204.94248 ug/Bee ae (240 

ug/Bee ai) slope = NA 

00093809, 1979 

/Acceptable 

Honey bee (Apis mellifera), Adult, C, / 

Fluazifop-butyl formulation, 25 EC% ai 

24 hr LD50 81.123065 ug/Bee ae (95 ug/Bee 

ai) slope = NA 

00093809, 1979 

/Acceptable 

Honey bee (Apis mellifera), Adult, C, / 

Fluazifop-P-butyl, 13.8% ai 

24 hr LD50 53.797401 ug/Bee ae (63 ug/Bee 

ai) slope = N.R. 

00162453, 1984 

/Acceptable 

Aquatic Invertebrate Data 

Water flea (Daphnia magna), Degredate X 

Water flea (Daphnia magna), <24 hr, static, / 

Fluazifop-butyl, 97.8% ai 

48 hr EC50 666 ppm 

48 hr EC50 240.1242724 ppm 

ae (281.2 ppm ai) slope = 5.21 

49224401, 1982 

IN REVIEW 

00087490, 1981 

/Acceptable 

Water flea (Daphnia magna), 12 hr, static, / 

Fluazifop-butyl (PP009), 94.8% ai 

48 hr EC50 8.53927 ppm ae (10 

ppm ai) slope = NA 

00087488, 1979 

/Acceptable 

Water flea (Daphnia magna), 12 hr, static, / 

Fluazifop-butyl (PP009), 25 EC% ai 

48 hr EC50 5.5505255 ppm ae 

(6.5 ppm ai) slope = NA 

00087488, 1979 

/Acceptable 

Water flea (Daphnia magna), 12 hr, static, / 

Fluazifop-butyl (PP009), 24% ai 

48 hr EC50 5.14064054 ppm ae 

(6.02 ppm ai) slope = NA 

00087489, 1980 

/Acceptable 

Water flea (Daphnia magna), <24 Hr, static, / 

Fluazifop-p-butyl RS 1:1 racemic, N.R.% ai 

48 Hr LC50 472.9901653 ppm 

ae (553.9 ppm ai) slope = N.R. 

00162452, 1983 

/Supplemental 

Water flea (Daphnia magna), <24 Hr, static, / 

Fluazifop-p-butyl RS 7:1 enhanced enantiomer, 

N.R.% ai 

48 Hr LC50 465.9025712 ppm 

ae (545.6 ppm ai) slope = N.R. 

00162452, 1983 

/Supplemental 

Water flea (Daphnia magna), <24 Hr, static, / 

Fluazifop-p-butyl RS 14:1 methanol prepartion, 

N.R.% ai 

48 Hr LC50 352.1594948 ppm 

ae (412.4 ppm ai) slope = N.R. 

00162452, 1983 

/Supplemental 

Water flea (Daphnia magna), <24 hr, static, / 

Fluazifop-butyl, RS11% ai 

48 hr EC50 472.9901653 ppm 

ae (553.9 ppm ai) slope = 10.96 

00162452, 1983 

/Supplemental 

Water flea (Daphnia magna), <24 hr, static, / 

Fluazifop-butyl, RS71% ai 

48 hr EC50 465.9025712 ppm 

ae (545.6 ppm ai) slope = N.R. 

00162452, 1983 

/Supplemental 

Water flea (Daphnia magna), <24 hr, static, / 

Fluazifop-butyl, RS14% ai 

48 hr EC50 352.1594948 ppm 

ae (412.4 ppm ai) slope = N.R. 

00162452, 1983 

/Supplemental 

Fiddler crab (Uca pugilator), 1.5 G, flow-through, / 

Fluazifop-butyl (PP009), 25.4% ai 

96 hr LC50 3.5011007 ppm ae 

(4.1 ppm ai) slope = NA 

00093806, 1980 

/Supplemental 

Mysid (Americamysis bahia), 6-8 D, flow-through, / 

Fluazifop-butyl (PP009), 98.6% ai 

96 hr LC50 184.448232 ppb ae 

(216 ppb ai) slope = 4.6 

00093805, 1980 

/Acceptable 
Page 66 of 78 

Mysid (Americamysis bahia), N.R., flow-through, / 

Fluazifop-P-butyl, 92.2% ai 

96 hr LC50 0.43550277 ppm ae 

(0.51 ppm ai) slope = N.R. 

42543201, 1991 

/Acceptable 

Pink shrimp (Penaeus duorarum), 0.21 g, flowthrough, / Fluazifop-butyl (PP009), 25.4% ai 96 hr LC50 5.123562 ppm ae (6 

ppm ai) slope = NA 

00093804, 1980 

/Acceptable 

Pacific oyster (Crassostrea gigas), EmbLrv, flowthrough, / Fluazifop-butyl (PP009), 98.6% ai 48 hr LC50 82.830919 ppb ae 

(97 ppb ai) slope = 5.5 

00131460, 1982 

/Acceptable 

Eastern oyster (Crassostrea virginica), SPAT, flowthrough, / Fluazifop-P-butyl, 90% ai 96 hr EC50 0.40134569 ppm ae 

(0.47 ppm ai) slope = 1.45 

41900601, 1991 

/Supplemental 

Mysid (Americamysis bahia), 48 hr, flow-through, / 

Fluazifop-butyl (PP009), 98.6% ai 

28 D LC50 66.3501279 ppb ae 

(77.7 ppb ai) slope = 2.1 

00093805, 1981 

/Supplemental 

Water flea (Daphnia magna), LifeCycle, flowthrough, / Fluazifop-butyl, 97.2% ai 21 D LOEC 213.48175 ppb ae 

(250 ppb ai) slope = NA 

00093807, 1981 

/Supplemental 

Fish Data 

Bluegill sunfish (Lepomis 

macrochirus), 4.13 g, flowthrough, / Fluazifop-butyl, 98.6% 

ai 

96 hr LC50 0.45258131 ppm ae (0.53 ppm ai) 

slope = NA 

00087485, 1981 

/Acceptable 

Bluegill sunfish (Lepomis 

macrochirus), 3.31 g, flowthrough, / Fluazifop-butyl, 25.8% 

ai 

Bluegill sunfish (Lepomis 

macrochirus), flow-through, 

25% Formulation 

96 hr LC50 2.27998509 ppm ae (2.67 ppm ai) 

slope = NA 

96 hr LC50 1.6 ppm 

00087486, 1981 

/Acceptable 

40829203, 1985 

IN REVIEW

Bluegill sunfish (Lepomis 

macrochirus), flow-through, 125 

g/l Formulation 

Fathead minnow (Pimephales 

promelas), <24 hr, static, / 

Fluazifop-butyl, 90.2% ai 

96 hr LC50 3.3 ppm

96 hr LC50 0.31595299 ppm ae (0.37 ppm ai) 

slope = 10.6 

40829205, 1985 

IN REVIEW

00093808, 1981 

/Supplemental 

Rainbow trout (Oncorhynchus 

mykiss), 2.2 g, flow-through, / 

Fluazifop-butyl, 25.8% ai 

Rainbow trout (Oncorhynchus 

mykiss), Static, Metabolite X

96 hr LC50 4.1842423 ppm ae (4.9 ppm ai) 

slope = 8.9 

96 hr LC50 240 ppm 

00087484, 1981 

/Acceptable 

49224402, 1994 

IN REVIEW 

Rainbow trout (Oncorhynchus 

mykiss) flow-through, 25% 

Formulation 

Rainbow trout (Oncorhynchus 

mykiss) flow-through, 125g/l 

Formulation 

Rainbow trout (Oncorhynchus 

mykiss), 6.2 g, static, / Fluazifopbutyl, 98% ai 

96 hr LC50 3.4 ppm 

96 hr LC50 5.4 ppm 

96 hr LC50 99.909459 ppm ae (117 ppm ai) 

slope = NA 

40829202, 1985 

IN REVIEW 

40829204, 1985 

IN REVIEW 

00087483, 1981 

/Acceptable 
Page 67 of 78 

Rainbow trout (Oncorhynchus 

mykiss), NR, flow-through, / 

Fluazifop-butyl, 93.7% ai 

96 hr LC50 1.20403707 ppm ae (1.41 ppm ai) 

slope = 15.2 

00131458, 1983 

/Supplemental 

Sheepshead minnow (Cyprinodon 

variegatus), 0.57 g, flow-through, / 

Fluazifop-butyl (Fusilade 4E), 

46.8EC% ai 

96 hr LC50 6.86557308 ppm ae (8.04 ppm ai) 

slope = 10.1 

00152173, 1985 

/Acceptable 

Sheepshead minnow (Cyprinodon 

variegatus), 0.37 g, flow-through, / 

Fluazifop-butyl (25EC 

formulation), 25.4% ai 

96 hr LC50 9.393197 ppm ae (11 ppm ai) slope 

= 13.2 

ACC070630, 1981 

/Acceptable 

Fathead minnow (Pimephales 

promelas), EarlyLife, flowthrough, / Fluazifop-butyl, 90.2% 

ai 

30 D LOEC 0.203234626 ppm ae (0.238 ppm ai) 

slope = NA 

00093808, 1981 

/Supplemental 

Avian Data 

Mallard duck (Anas platyrhynchos), NR, oral, / 

Fluazifop-butyl, 93.4% ai 

14 D LD50 4269.635 ppm 

ae (<5000 ppm ai) slope = 

NA 

00131457, 1982 /Acceptable 

Mallard duck (Anas platyrhynchos), 15 D, 

dietary, / Fluazifop-butyl, 99.6% ai 

8 D LC50 21348.175 ppm 

ae (<25000 ppm ai) slope = 

NA 

00087481, 1980 /Supplemental 

Mallard duck (Anas platyrhynchos), 16 WKS, 

oral, / Fluazifop-P-butyl, 95.8% ai 

14 D LD50 3012.654456 

mg/kg ae (<3528 mg/kg ai) 

slope = N.R. 

40829201, 1985 /Acceptable 

Ring-necked pheasant (Phasianus colchicus), 13 

D, dietary, / Fluazifop-butyl (Dieldrin), 99.6% 

ai 

8 D LD50 ppm ae 

(20767.77 ppm ai) slope = 

NA 

00087482, 1982 /Acceptable 

Bobwhite quail (Colinus virginianus), 11 D, 

dietary, / Fluazifop-P-butyl, 89.09% ai 

8 D LC50 4466.03821 ppm 

ae (<5230 ppm ai) slope = 

N.A. 

40851401, 1985 /Acceptable 

Bobwhite quail (Colinus virginianus), 11 D, 

dietary, / Fluazifop-p-butyl, 95.8% ai 

8 D LC50 4466.03821 ppm 

ae (<5230 ppm ai) slope = 

N.A. 

40859401, 1985 /Acceptable 

Mallard duck (Anas platyrhynchos), 9 D, 

dietary, / Fluazifop-P-butyl, 95% ai 

8 D LC50 4141.54595 ppm 

ae (<4850 ppm ai) slope = 

N.R. 

00087481, 1987 /Acceptable 

Bobwhite quail (Colinus virginianus), 

reproductive study, / Fluazifop-butyl, 99.6% ai 

31 Wk LOAEL 42.69635 

ppm ae (<50 ppm ai) slope 

= NA 

00093802, 1981 /Supplemental 

Mallard duck (Anas platyrhynchos), 

reproductive study, / Fluazifop-butyl, 99.6% ai 

23 Wk LOAEL 42.69635 

ppm ae (<50 ppm ai) slope 

= NA 

00093801, 1981 /Supplemental 

Mammalian Data

Acute Toxicity Data on FLUAZIFOP-BUTYL & FLUAZIFOP-P-BUTYL.

Acute Studies with Fluazifop-butyl (PC 122805)

Guideline No./ Study Type MRID No. Results Toxicity Category 
Page 68 of 78 

Acute Toxicity Data on FLUAZIFOP-BUTYL & FLUAZIFOP-P-BUTYL.

870.1100 

Acute oral toxicity/rats 

(PP009; 97.2%) 

 00162439 

(1983) 

LD50 = 1940 mg/kg (males) ± 1193-

2758 mg/kg 

LD50 = 2653 mg/kg (females) ± 1764-

3625 mg/kg 

III 

870.1200 Acute dermal 

toxicity/rabbits 

(PP009; 97.2%) 

00162439 

(1983) 

LD50 > 2mL/kg (males and females) 

or approximately 2000 mg/kg 

III 

870.1300 Acute inhalation 

toxicity/rats 

(PP009; 97%) 79/ISK034/387 

46082901, 

same as 

41563701 

(1979) 

LC50 > 2.3 mg/L for 43% with a 

particle size <5 μm 

LC50 >4.37 mg/L for 83% with a 

particle size <10 μm 

III 

870.2400 Acute eye 

irritation/rabbit 

(PP009; 93.3%) 79/ILK9/068 

 00088855 

(1979) 

Non-irritating IV 

870.2500 Acute dermal 

irritation/rabbit 

(PP009; 93.3%) 79ILK8/056 

 00088853 

(1979) 

Mild erythema at 72 hours IV 

870.2600 Skin 

sensitization/GP (PP009; 

99 6%) 80/ILK026/349

 00088854 

(1980) 

Not a dermal sensitizer 

Acute Studies with Fluazifop-P-butyl (PC 122809)

Guideline No./ Study Type MRID No. Results Toxicity Category 

870.1100 Acute oral 

toxicity/rats 

(PP005; 93.7% & 86.3% ) 

00162440 

(1984) 

LD50 = 3680 mg/kg for males rats 

LD50 = 2451 mg/kg for female rats 

III 

III 

870.1200 Acute dermal 

toxicity/rabbits 

(PP005; 93.7% & 86.3%) 

00162440 

(1984) 

LD50 > 2000 mg/kg or >1.73 mL/kg III 

870.1300 Acute inhalation a

toxicity/rats 

(PP005; 24.6%) CTL/P/3331 

41917904 

(1991) 

LC50 > 1.7 mg/L III 

870.2400 Acute eye 

irritation/rabbit 

(PP005; 86.3%) CTL/P/856 

00162441 

(1983) 

Mild irritation, cleared within 3 days IV 

870.2500 Acute dermal 

irritation/rabbit 

(PP005; 86.3%) CTL/P/856 

00162441 

(1983) 

Slight irritation, cleared within 72 

hours 

IV 

870.2600 Skin 

sensitization/GP (PP005; 

99.6%) 80/ILK026/349 

00162441 

(1983) 

Not a skin sensitizer 

a

 This study was conducted with a mixture of 24.6% fluazifop-P-butyl and 7.0% fenoxyprop-P-ethyl, however, the concentration 

fluazifop-P-butyl in the inhalation chamber was determined to be 1.7 mg/L. PPOO9 was used to indicate the technical grade of 

fluazifop-butyl. PPOO5 was used to indicate the technical grade of fluazifop-P-butyl. 
Page 69 of 78 

Subchronic, Chronic, Developmental, Reproductive and Other Toxicity Profile on 

Fluazifop-butyl [FB] and Fluazifop-P-butyl [FPB].

Guideline No./ 

Study Type 

MRID No. (year)/ 

Classification /Doses 

Results 

870.3100 

90-Day oral toxicity 

(rat) with FB 

00093820 (1980) 

Acceptable/guideline 

0, 10, 100, 2000 ppm 

M: 0, 0.7, 7.1, 144.5 

mg/kg/day 

F; 0, 0.8, 8.0, 161.9 

mg/kg/day 

NOAEL=0.7 mg/kg/day 

LOAEL=7.1 mg/kg/day based on liver and kidney 

histopathology. 

870.3100 

90-Day oral toxicity 

(rat) with FPB 

46158402 (1985) 

Acceptable/guideline 

0, 10, 100, 2000 ppm 

—F: 0, 0.5, 5, 100 

mg/kg/day 

NOAEL=0.5 mg/kg/day 

LOAEL=5 mg/kg/day based on decreased spleen weight and 

decreased hematological parameters in males. Dose related 

testicular weight decrement and cholesterol depression were 

also seen. 

870.3150 

90-Day oral toxicity 

(dog) with FB 

00093821 (1980) 

Acceptable/guideline 

0, 5, 25, 125/250 

mg/kg/day 

NOAEL = 25 mg/kg/day 

LOAEL = 125/250 mg/kg/day based on multiple pathologies 

in 3 dogs (2 males and 1 female) killed at 1 month dosed at 

250 mg/kg/day. Also seen were body weight loss gut 

lesions, severe eye lesions and hepatotoxicity. In remaining 

surviving dogs dosed at 125 mg/kg/day , mild to equivocal 

liver lesions were seen. 

870.3150 

90-Day oral toxicity 

(hamster) with FPB 

46082902 (2001) 

Acceptable/guideline 

Males: 0, 19.5, 78.3 or 

291.9 mg/kg/day 

Females: 0, 19.9, 79.0 or 

319.6 mg/kg/day 

NOAEL = M/F: 78.3/79.0 mg/kg/day 

LOAEL = M/F: 291.9/319.6 mg/kg/day based on decreased 

body weight/body weight gain and food efficiency in males 

and evidence of liver toxicity; centrilobular eosinophilia/loss 

of glycogen in males and females. 

870.3200 

21/28-Day dermal 

toxicity (rabbit) with 

FB 

00093819 (1980) 

Acceptable/guideline 

0, 100, 500, 2000 

mg/kg/day 

NOAEL = 100 mg/kg/day 

LOAEL = 500 mg/kg/day based on death in 1 male and at 

2000 mg/kg/day, death 4 males and 5 females, possibly due 

to kidney failure. 

870.3250 

90-Day dermal 

toxicity (species) 

Not required 

870.3465 

90-Day inhalation 

toxicity (species) 

Not required. 

870.3700a 

Prenatal 

developmental in 

(Sprague Dawley 

rats) with FB 

0008857, 92067047 

(1981) 

Acceptable/guideline 

0, 10, 50, 200 mg/kg/day 

Maternal NOAEL = 200 mg/kg/day 

LOAEL = None based on maternal weight decrement due to 

gravid uterine weight decrement. 

Developmental NOAEL=none 

LOAEL=10 mg/kg/day based on delayed ossification. 
Page 70 of 78 

Subchronic, Chronic, Developmental, Reproductive and Other Toxicity Profile on 

Fluazifop-butyl [FB] and Fluazifop-P-butyl [FPB].

Guideline No./ 

Study Type 

MRID No. (year)/ 

Classification /Doses 

Results 

Malformations NOAEL = 50 mg/kg/day 

LOAEL = 200 mg/kg/day based on diaphragmatic hernia. 

870.3700a 

Developmental 

toxicity (Sprague 

Dawley rat) with FB 

00088858, 92067048, 

92967020 (1981) 

Acceptable/guideline 

0, 1.0, 5.0, 10, 200 

mg/kg/day with FB 

Maternal NOAEL=200 mg/kg/day. 

LOAEL=None based on maternal weight decrement 

partially explained by gravid urine weight decrement. 

Developmental NOAEL=1 mg/kg/day. 

LOAEL=5 mg/kg/day based on fetal weight decrement and 

increased incidence of small fetuses and delayed 

ossification. 

Malformations NOAEL= 10 mg/kg/day 

LOAEL=200 mg/kg/day based on increased incidence of 

diaphragmatic hernia. 

870.3700a 

Developmental 

toxicity (Wistar rats) 

with FPB 

46158401 (1991) 

Acceptable/guideline 

0, 0.5, 1.0, 20, 300 

mg/kg/day 

Maternal NOAEL=20 mg/kg/day 

LOAEL=300 mg/kg/day based on body weight gain 

decrement. 

Developmental NOAEL=1.0 mg/kg/day 

LOAEL=20 mg/kg/day based on delayed ossification in 

skull bones, cervical arches and centrum in fetuses and 

litters and delayed ossification in the manus and pes. 

870.3700a 

Developmental 

Toxicity (Wistar rats) 

with FPB 

46082903 (1989) 

Acceptable/guideline 

0, 2, 5 or 100 mg/kg/day 

Maternal NOAEL=100 mg/kg/day 

LOAEL= None based no maternal toxicity. 

Developmental NOAEL=2.0 mg/kg/day 

LOAEL=5.0 mg/kg/day based on based on dose related 

delayed ossification in skull bones [occipital and parietal] in 

fetuses and litters.

870.3700a 

Developmental 

Toxicity (Wistar rats) 

with FPB

46082013 (1990) 

Acceptable/guideline 

0, 2.0, 5.0, 100 

mg/kg/day 

Maternal NOAEL=100 mg/kg/day 

LOAEL= None based on no toxic effects 

Developmental NOAEL=2.0 mg/kg/day 

LOAEL=5.0 mg/kg/day based on delayed ossification in 

skull bones, sternebrae bipartite, sternebrae and calcenum 

unossifided in fetuses and litters. 

The overall conclusions based on a weight of evidence on the five studies of developmental toxicity in the rat 

were a NOAEL/LOAEL = 2.0/5.0 mg/kg/day based on fetal weight decrement and delayed ossification. 

870.3700b 

Developmental 

toxicity (NZW 

rabbit) with FB 

00088856, 92067049, 

92067021 (1981) 

Acceptable/guideline 

0, 10, 30, 90 mg/kg/day 

Maternal NOAEL=30 mg/kg/day 

LOAEL=90 mg/kg/day based on abortions. 

Developmental NOAEL=30 mg/kg/day 

LOAEL=90 mg/kg/day based on nominal increases in 

delayed ossification, total litter loss, abortions, small fetuses, 

cloudy eyes all above mean or range of historical controls

870.3700b 

Developmental 

toxicity (NZW 

rabbits) with FPB 

46082904 (1993) 

Acceptable/guideline 

0, 2, 10, 50 mg/kg/day 

Maternal NOAEL=10 mg/kg/day 

LOAEL=50 mg/kg/day based death, abortions and body 

weight loss 

Developmental NOAEL=10 mg/kg/day 

LOAEL=50 mg/kg/day based on increased incidence of 13th

rib and delayed ossification in sternebrae 2. 
Page 71 of 78 

Subchronic, Chronic, Developmental, Reproductive and Other Toxicity Profile on 

Fluazifop-butyl [FB] and Fluazifop-P-butyl [FPB].

Guideline No./ 

Study Type 

MRID No. (year)/ 

Classification /Doses 

Results 

870.3800 

Reproduction and 

fertility effects 

(rats) with FB 

00088859, 92067050 

(1981) 

Acceptable/guideline 

0, 10, 80, 250 ppm 

M/F: 0/0, 0.74/0.88, 

5.8/7.1, 21.7/17.5 

mg/kg/day 

Parental/Systemic NOAEL = M/F 0.74/7.1 mg/kg/day 

LOAEL = M/F 5.8/ 21.7 mg/kg/day based on decreased 

spleen wt. in males & increased absolute & relative liver & 

kidney wts. & geriatric nephropathy in females. 

Offspring NOAEL = 7.1 mg/kg/day 

LOAEL = 21.7 mg/kg/day based on pup viability in f1 and 

f2 pups during lactational day 1, 4, 11, 18 & 25 and 

decreased f2 pup weight on lactational day 25. 

Reproductive NOAEL = M/F 0.74/0.88mg/kg/day 

LOAEL = M/F 5.8/7.1 mg/kg/day based on decreased abs. & 

rel testes & epididymal weight and in females decreased 

pituitary & uterine weights. Sperm counts not available.

Conclusions on the 2-generation study on reproduction in the Sprague Dawley rat: The cause of the dose related 

testes wt decrease in the P0 and F1 generations has not been demonstrated, but no sperm counts, morphology, 

motility have been conducted to date. Extensive short term studies on testes weight, testes histopathology, and 

endocrine effects (MRID# 46082911, 46082916, 46082917,46082920 & 46082920, see table 4.1d) failed to find 

the reason for the testes weight decrement in the rat and hamster. However, since the most sensitive tests for 

effects on sperm were not conducted (sperm count, motility and morphology as indicated in the 1996 guidelines), 

it is concluded that testes weight decrement from possible decrements in sperm seen in the rat reproduction and 

the chronic study in hamsters have not been adequately eliminated. The histology on the testes does not support 

an effect, but histology is insufficiently sensitive to detect an slight effect. 

870.4100a 

Chronic toxicity 

(rats) 

870.4300 satisfies the 

requirement 

870.4100b 

Chronic toxicity 

(dog) with FB 

00131462, 00131463, 

92067018 (1982) 

Acceptable/guideline 

0, 5, 25, 125 mg/kg/day 

NOAEL = 5 mg/kg/day 

LOAEL = 25 mg/kg/day based on marginally increased 

incidence adrenal fatty vacuolation & increased incidence of 

thymic involution and at 125 mg/kg/day death of 4/6 males 

and 2/6 females, eye, gastrointestinal tract lesions, adrenal 

and bone marrow pathology & thymic involution. 

870.4200 

Carcinogenicity 

(hamster) with FPB 

4534501, 46082905 

(2001) 

Acceptable/guideline 

0, 0, 200, 750, 3000 ppm 

M: 0, 0, 12.5, 47.4, 

193.6 mg/kg/day F: 0, 0, 

12.1, 45.5, 181.4 

mg/kg/day 

NOAEL =M/F 12.5/12.1 mg/kg/day 

LOAEL = 47.5/45.5 mg/kg/day based on based on increased 

incidence of males with reduced sperm, testicular 

degeneration, eye cataract changes, liver inflamation and 

gall stones and in females, increased incidence of ovarian 

stroma cell/sex chord hyperplasia. 

No evidence of carcinogenicity 

870.4300 

Chronic/Carcinogeni

city 

(rat) with FB 

41563703 (1985) 

Acceptable/guideline 

0, 2, 10, 80, 250 ppm 

M: 0, 0.10, 0.51, 4.15, 

12.3 mg/kg/day 

F: 0, 0.13, 0.65, 5.2, 

16.0 mg/kg/day 

NOAEL =M/F 0.51/5.2 mg/kg/day 

LOAEL =M/F 4.15/16.0 mg/kg/day based on increased 

mortality & nephropathy exacerbated by respiratory stress, 

and in females possible increased basal and/or 

follicular/luteal cysts. 

No evidence of carcinogenicity 

 
Page 72 of 78 

Subchronic, Chronic, Developmental, Reproductive and Other Toxicity Profile on 

Fluazifop-butyl [FB] and Fluazifop-P-butyl [FPB].

Guideline No./ 

Study Type 

MRID No. (year)/ 

Classification /Doses 

Results 

870.6100a Acute 

neurotoxicity in hens 

with FB 

00093818 (1981) 

Acceptable/guideline 

0, 3750, 7500 or 15000 

or 15000 mg/kg 

Fluazifop-butyl exposed hens showed no evidence of 

delayed neurotoxicity. 

870.6200a 

Acute neurotoxicity 

screening battery 

Not required 

870.6200b 

Subchronic 

neurotoxicity 

screening battery 

Not required 

870.6300 

Developmental 

neurotoxicity 

Not required 

870.7485 

Metabolism and 

pharmacokinetics 

(rats) with FB 

00093822 through 

00093828 (1981) 

Acceptable/guideline 

1 mg/kg and 1000 

mg/kg 

Fluazifop-butyl is rapidly hydrolyzed to fluazifop acid by 

blood enzymes and excreted as the acid and its conjugates in 

the urine of males and females. Due to biliary excretion 

parent compound, fluazifop acid and its conjugates are 

excreted in the feces of males at much higher proportions 

than in feces of the female. Excretion was complete in 7 

days, with the exception of small amounts in the fat in some 

rats. 

870.7600 

Dermal penetration 

(human) 

 MRID# 46082918 a human study/NG satisfies guideline 

870.7600. 

NG Comparative 

metabolism with FB 

and FPB in rats 

00162445, 0012446 

(1983) Acceptable/NG 

1 mg/kg 

FB is hydrolyzed and the [S] enantiomer is converted to the 

[R] enantiomer. Whether fluazifop-butyl [RS] (50:50) or 

fluazifop-P-butyl [S] (90:10) is administered, within a hour 

the blood contained a mixture composed of fluazifop acid in 

a ratio of [R] 95% and [S] 3%. The two products behaved 

similarly and reached the same equilibrium within 

experimental error. 

NG Plasma level 

time course with FB 

and FPB in rats 

46082910 (1998) 

Acceptable/NG 

200 mg/kg 

The time course of plasma levels and elimination of the acid 

metabolite were similar for both fluazifop-butyl and 

fluazifop-P-butyl. Plasma levels of the acid from both 

isomers were much higher in males than in females. The 

data support previous studies. 

NG Absorption and 

excretion study in 

hamsters with FPB 

46082923 (2002) 

Acceptable/NG 

0, 200, 750, 3000 ppm 

The study was conducted in two phases, Phase 1- single 

dose followed by 3 days of unlabeled test material and Phase 

2 - 24 hour feeding of labeled test material followed by 3 

day of unlabeled test material. Data were consistent with 

excretion data from other species. The system appeared 

saturated, since the ratio of the 3000/200 ppm dose levels 
Page 73 of 78 

Subchronic, Chronic, Developmental, Reproductive and Other Toxicity Profile on 

Fluazifop-butyl [FB] and Fluazifop-P-butyl [FPB].

Guideline No./ 

Study Type 

MRID No. (year)/ 

Classification /Doses 

Results 

was much lower than the ratio of respective plasma levels, 

especially for males. 

NG Absorption, 

excretion and tissue 

retention in mice 

with FB 

46082925 (1992) 

Acceptable/NG 

1 and 150 mg/kg 

Male mice excreted proportionally more in feces and less in 

urine than females. Although males excreted more than 

females in the feces and females excreted more than males 

in the urine, the difference between males and female mice 

was smaller than with male and female rats. The study 

showed individual variability in excretion, similar to that 

found in the rats, dog and human, although analytical 

deviation may have explained part of the variation. 

NG Absorption and 

excretion in dogs 

with FB 

0093829 (1981) 

Acceptable/NG 

1 mg/kg 

One dog showed delayed absorption. Excretion rate similar 

to females rats. No evidence of biliary excretion. 

NG Peroxasome 

proliferation in mice, 

rats, hamsters and 

humans with FPB 

46082919 (1988) 

Acceptable/NG 

0, 80, 250, 1000 or 2000 

ppm 

In vivo and in vitro peroxasome proliferation was studied in 

the mouse, rat and hamster and in vitro human hepatocytes. 

Proliferation in hepatocytes from the greatest to the smallest 

was: mice > rats > hamster >> human. No increase in cell 

replication was seen at any dose. 

NG 

Androgen/estrogen 

activity with FPB & 

acid; FB & acid 

metabolite 

46082916 (2001) 

Acceptable/NG 

No agonist or antagonist activity was detected for FPB or FB 

or their acid metabolites. Using recombinant yeast strains 

expressing human androgen receptor or estrogen receptor, 

the intrinsic androgenic, anti-androgenic, estrogenic, antiestrogenic activity of FPB, FB and their respective acid 

metabolites have been assessed by absorbance in a 

transcription assay. Positive antagonists were 

hydrotamoxifen and flutamide, which induced appropriate 

antagonic activity. Agonistic activity assessed by 

comparison to 17β-estradiol and dihydrotestosterone; 

antagonic activity was assessed by inhibition of 17βestradiol 

and dihydrotestosterone activity. No agonist or antagonic 

activity was found within 7 orders of magnitude (oom) 

greater than the conc. of estradiol transcription, 4 oom 

greater for inhibition of estradiol transcription and 6 oom for 

agonistic activity of dihydrotestosterone and up to 156 μM 

antagonist activity by a dose related decrease in 

dihydrotestosterone-mediated androgenic activity. 

NG Dermal 

absorption in humans 

with FB 

46082918, 46082927, 

4153704 (1991) 

Acceptable/NG 

2 mg & 200 mg/person 

Dermal absorption was 8.6% at 2 mg/person and 1.9% at 

200 mg/person 

NG Dermal 

multidose in humans 

with FB 

46082908 (1989) 

Acceptable/NG 

20 mg 

Six male humans were dermally dosed for 5 days at 20 

mg/person and the pharmacokinetics followed The study 

was consistent with other studies in humans, dogs and 

female rats. Estimated one-half-life was 12.6 to 17.3 hours, 

which was much more uniform than seen in other studies. 

There was no evidence of accumulation of the dose. 
Page 74 of 78 

Subchronic, Chronic, Developmental, Reproductive and Other Toxicity Profile on 

Fluazifop-butyl [FB] and Fluazifop-P-butyl [FPB].

Guideline No./ 

Study Type 

MRID No. (year)/ 

Classification /Doses 

Results 

NG Oral absorption, 

metabolism and 

excretion in men 

with FB 

00131464 (1983) 

Acceptable/NG 

0.07mg/kg 

Metabolism was similar to the female rat and dog. 

Absorption was delayed in one man and excretion in the 

urine was variable with no evidence of biliary excretion. 

 
Page 75 of 78 

APPENDIX C: Example of SIP INPUT and OUTPUT 

Drinking Water Exposure 

Drinking water for the purposes of terrestrial organism risk assessment is defined as that portion 

of an organism’s daily water intake that is not met by dietary or metabolic sources and must be 

consumed in liquid form. Typical drinking water sources for wildlife in pesticide use areas may 

include on-field puddles, irrigation equipment (e.g., drip irrigation in grape cultivation), dew 

deposited on treated plants, and off-field surface water exposures. 

The Screening Imbibition Program (SIP v.1.0, Released June 15, 2010) was used to calculate an 

upper bound estimate of exposure using fluazifop’s solubility in water (1 mg/L at 25oC). Using 

TGAI data for the most sensitive acute (fluazifop-P-butyl LD50 3528 mg a.i./kg-bw for the 

Mallard duck, MRID 40829201) and chronic (fluazifop-butyl NOAEC <50 mg a.i./kg-diet, 

Mallard duck, MRID 00093801) avian toxicity endpoints and the most sensitive acute fluazifopbutyl (LD50 = 1940 mg a.i./kg-bw, male rat, MRID 00162439) and chronic (fluazifop-butyl 

reproduction NOAEC = 80 mg a.i./kg-diet, MRID 00088859) mammalian toxicity endpoints. 

Drinking water exposure alone was determined not to be a potential pathway of concern for 

avian and mammalian species on an acute and chronic basis. Detailed information about the SIP 

v.1.0, as well as the tool, can be found on the EPA’s website at 

http://www.epa.gov/pesticides/science/models_pg.htm#terrestrial. 

 

 Table 1. Inputs 

 Parameter Value 

 Chemical name Fluazifop 

 Solubility (in water at 25oC; mg/L) 1 

 

 Mammalian LD50 (mg/kg-bw) 1940 

 Mammalian test species laboratory rat 

 

Body weight (g) of "other" mammalian 

species 

 

 Mammalian NOAEL (mg/kg-bw) 4 

 Mammalian test species laboratory rat 

 

Body weight (g) of "other" mammalian 

species 

 

 Avian LD50 (mg/kg-bw) 3528 

 Avian test species Duck 

 Mineau scaling factor 1.15 

 

 Mallard NOAEC (mg/kg-diet) <50 

 Bobwhite quail NOAEC (mg/kg-diet) <50 

 

 Table 2. Mammalian Results 

Parameter Acute Chronic 

Upper bound exposure (mg/kg-bw) 0.1720 0.1720 

Adjusted toxicity value (mg/kg-bw) 1492.1715 3.0766 
Page 76 of 78 

Ratio of exposure to toxicity 0.0001 0.0559 

Conclusion* Drinking water exposure alone is NOT a 

potential concern for mammals 

Drinking 

water 

exposure 

alone is 

NOT a 

potential 

concern 

for 

mammals

 

Table 3. Avian Results 

Parameter Acute Chronic 

Upper bound exposure (mg/kg-bw) 0.8100 0.81 

Adjusted toxicity value (mg/kg-bw) 1831.80 2.4806 

Ratio of exposure to acute toxicity 0.0004 0.3265 

Conclusion* Drinking water exposure alone is NOT a 

potential concern for birds 

Drinking 

water 

exposure 

alone is 

NOT a 

potential 

concern 

for birds 

*Conclusion is for drinking water exposure alone. This does not combine all routes of exposure. 

Therefore, when aggregated with other routes (i.e., diet, inhalation, dermal), pesticide exposure through 

drinking water may contribute to a total exposure that has potential for effects to non-target animals. 

 
Page 77 of 78 

APPENDIX D: STIR inputs and outputs 

Inhalation Exposure 

The Screening Tool for Inhalation Risk (STIR v.1.0, November 19, 2010) was used to calculate 

an upper bound estimate of exposure using fluazifop-butyl’s vapor pressure (0.055 mm Hg at 

20oC) and molecular weight (383.37 g/mol) for vapor phase exposure as well as the maximum 

application rate (1.125 lbs a.i./A, which is the maximum seasonal application rate (to pecans, 

grapes, citrus) and method of application (aerial spray) for spray drift. STIR incorporates results 

from several toxicity studies including acute oral and inhalation rat toxicity endpoints obtained 

from the “six-pack” of core studies, which are a series of six guideline studies that are submitted 

to the Registration Division of the Office of Pesticide Programs on laboratory rats for technical 

and formulated products of a pesticide (rat acute oral (TGAI): LD50 = 1940 mg a.i./kg-bw; rat 

inhalation (TGAI): LC50 >2.3 mg/L (MRID 46082901). In addition, the most sensitive acute oral 

avian toxicity endpoint (Mallard duck, LD50 = 4269 mg a.i./kg-bw (MRID 00131457) was used. 

Based on the results of the STIR model, inhalation exposure alone was not determined to be a 

potential pathway of concern for avian or mammalian species on an acute basis as a result of spray 

applications of fluazifop-butyl. 

Inhalation exposure via spray drift and/or vapor-phase of the pesticide alone does not appear to be 

of concern. The analysis of the inhalation route in STIR does not consider that aggregation with 

other exposure pathways such as dietary, dermal, or drinking water may contribute to a total 

exposure that has a potential for effects to non-target animals. However, the Agency does consider 

the relative importance of other routes of exposure in situations where data indicate that pesticide 

exposures through other routes may be potentially significant contributors to wildlife risk (USEPA, 

2004). Detailed information about STIR v.1.0, as well as the tool, can be found on the EPA’s 

website at: http://www.epa.gov/pesticides/science/models_pg.htm#terrestrial. 

 

Input 

Application and Chemical Information 

Enter Chemical Name Fluazifop butyl

Enter Chemical Use pecans, grapes

Is the Application a Spray? (enter y or n) y

If Spray What Type (enter ground or air) air

Enter Chemical Molecular Weight (g/mole) 383.37

Enter Chemical Vapor Pressure (mmHg) 5.50E-02

Enter Application Rate (lb a.i./acre) 1.125

 

Toxicity Properties 

Bird 

Enter Lowest Bird Oral LD50 (mg/kg bw) 4269

Enter Mineau Scaling Factor 1.15

Enter Tested Bird Weight (kg) 1.58

Mammal 

Enter Lowest Rat Oral LD50 (mg/kg bw) 1940
Page 78 of 78 

Enter Lowest Rat Inhalation LC50 (mg/L) 2.3

Duration of Rat Inhalation Study (hrs) 4

Enter Rat Weight (kg) 0.35

 

Output 

Results Avian (0.020 kg ) 

Maximum Vapor Concentration in Air at Saturation 

(mg/m3) 1.13E+03

Maximum 1-hour Vapor Inhalation Dose (mg/kg) 1.43E+02

Adjusted Inhalation LD50 2.03E+01

Ratio of Vapor Dose to Adjusted Inhalation LD50 7.01E+00

Maximum Post-treatment Spray Inhalation Dose (mg/kg) 1.08E-01

Ratio of Droplet Inhalation Dose to Adjusted Inhalation 

LD50 5.31E-03

 

Results Mammalian (0.015 kg ) 

Maximum Vapor Concentration in Air at Saturation 

(mg/m3) 1.13E+03

Maximum 1-hour Vapor Inhalation Dose (mg/kg) 1.79E+02

Adjusted Inhalation LD50 1.37E+02

Ratio of Vapor Dose to Adjusted Inhalation LD50 1.31E+00

Maximum Post-treatment Spray Inhalation Dose (mg/kg) 1.36E-01

Ratio of Droplet Inhalation Dose to Adjusted Inhalation 

LD50 9.92E-04