OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

November 6, 2014 

PC Code: 129131 

MEMORANDUM DP Barcode: 421244 

SUBJECT: EFED Registration Review Problem Formulation for Fenpyroximate 

FROM: Christina Wendel, Biologist 

Greg Orrick, Environmental Scientist 

 Environmental Risk Branch 2 

Environmental Fate and Effects Division (7507P) 

REVIEWED N.E. Federoff, Wildlife Biologist

BY: James Lin, Environmental Engineer 

 Jean Holmes, DVM, MPH, Risk Assessment Process Leader 

Environmental Fate and Effects Division (7507P) 

THROUGH: Brian Anderson, Branch Chief 

Environmental Risk Branch 2 

 Environmental Fate and Effects Division (7507P) 

 

TO: Miguel Zavala, Chemical Review Manager

 Patricia Parrott, Branch Chief 

Risk Management and Implementation Branch 3 

Pesticide Re-evaluation Division (7508P) 
2 

Table	of	Contents	

1. Executive summary ................................................................................................................. 3

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

a. Mode of Action .................................................................................................................... 3

3. Use Characterization ............................................................................................................... 4

4. Conclusions from Previous Risk Assessments ....................................................................... 8

a. Ecological Risk Assessment ................................................................................................ 8

b. Drinking Water Exposure Assessments ............................................................................... 9

c. Clean Water Act Programs ................................................................................................ 10

5. Environmental Fate and Transport........................................................................................ 10

a. Transformation Products .................................................................................................... 12

6. Receptors............................................................................................................................... 17

a. Effects to Aquatic Organisms ............................................................................................ 18

b. Effects to Terrestrial Organisms ........................................................................................ 19

c. Ecological Incidents ........................................................................................................... 20

7. Exposure Pathways of Concern ............................................................................................ 21

8. Analysis Plan ........................................................................................................................ 21

a. Stressors of Concern .......................................................................................................... 21

b. Measures of Exposure ........................................................................................................ 22

c. Measures of Effect ............................................................................................................. 22

9. Endangered Species Assessments ......................................................................................... 22

10. Endocrine Disruptor Screening Program ........................................................................... 23

11. Preliminary Identification of Data Gaps ............................................................................ 23

a. Environmental Fate ............................................................................................................ 23

b. Effects ................................................................................................................................ 26

12. References .......................................................................................................................... 35

a. Submitted Product Chemistry and Environmental Fate Studies ........................................ 35

b. Submitted Ecological Toxicity Studies .............................................................................. 36

APPENDIX A. STIR & SIP Model Outputs ................................................................................ 41
3 

1. Executive summary 

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

formulation (attached) for the ecological risk, environmental fate, endangered species, and 

drinking water assessments to be conducted as part of the registration review of fenpyroximate. 

The problem formulation describes the methods planned to be used during the completion of 

drinking water and ecological risk assessments in support of registration review and provides an 

overview of the environmental fate, ecological effects, potential risks associated with the use, 

and uncertainties unique to the risk assessment of fenpyroximate. This document also identifies 

additional studies that would be beneficial to the conduct of an ecological risk assessment. 

Major findings include: 

Data Needs 

 Aerobic soil metabolism study (OCSPP Guideline 835.4100) of one to three soils 

 Anaerobic aquatic metabolism study (OCSPP Guideline 835.4400) of one system 

 Fish bioconcentration study (OCSPP Guideline 850.1730) 

 ILVs of ECMs in soil and water (OCSPP Guideline 850.6100) or new, state-of-the-art 

methods and associated ILV reports 

 Chronic mysid toxicity study (OSCPP Guideline 850.1350) 

 Freshwater fish full life-cycle toxicity study (OSCPP Guideline 850.1500) 

 Sediment toxicity study (OSCPP Guideline 850.1735) 

 Avian acute oral toxicity – passerine species (OSCPP Guideline 850.2100) 

 Acute and chronic larval oral honeybee toxicity studies (OECD Guideline 237 and NonGuideline, respectively) 

 Chronic adult oral honeybee toxicity study (Non-Guideline) 

 Semi-field testing for pollinators (OECD Guideline 75) 

2. Introduction 

Fenpyroximate is a pyrazole contact insecticide and miticide that was first registered in 2000, 

with new agricultural uses added since. Three end-use formulations containing fenpyroximate 

are currently registered for use in the United States. 

a. Mode of Action 

Fenpyroximate is a pyrazole contact insecticide and miticide that inhibits mitochondrial complex 

I electron transport. The mode of action blocks cell respiration by blocking formation of 

adenosine triphosphate (ATP), causing the target pest to lose motor control and collapse. 

Fenpyroximate specifically targets the proton-translocation in NADH:ubiquinone oxidoreductase 

enzyme blocking ubiquinone reduction. 

NADH:ubiquinone oxidoreductase, also known as respiratory complex I of mitochondria, 

transfers electrons from NADH to ubiquinone (coenzyme Q) and links this process with 
4 

translocation of protons across the inner membrane to the cytoplasmic side creating a proton 

gradient which drives the synthesis of ATP. NADH:ubiquinone oxidoreductase enzyme is 

comprised of a number of subunits. The number of subunits and total mass of this enzyme and 

density within mitochondria depends on the organism. It consists of at least 41 different subunits 

in mammals. The highest number of subunits is 46 for bovine heart mitochondria, whereas 

bacteria have a minimum of 14 subunits. The total mass of the enzymes ranges from 

approximately 500 to 1000 kiloDaltons (kDa), depending on the organism. Sensitivity of an 

organism to fenpyroximate is expected to be affected by the specific organism 

NADH:ubiquinone oxidoreductase enzyme affinity with fenpyroximate, the density of the 

NADH:ubiquinone oxidoreductase enzyme within mitochondria, and the presence of alternative 

energy pathways. 

 

In addition to the acute respiratory activity, at sublethal levels fenpyroximate causes inhibition of 

molting of all immature stages (as in insect growth regulators), inhibits oviposition, and 

decreases feeding action. 

3. Use Characterization 

Three end-use formulations containing 5% fenpyroximate are currently registered for use in the 

United States. Fujimite® 5EC (EPA Reg. No. 71711-19) and NAI-2399-2® 5EC (EPA Reg. No. 

71711-40) include many of the same outdoor agricultural, ornamental, and greenhouse uses. 

Specific use sites, some of which overlap, include exotic fruits, citrus fruits, cotton, cucumbers, 

corn, fruiting vegetables, grapes, hops, low-growing berries except cranberries, melons, mint, 

pome fruits, tuberous and corm vegetables (EPA Reg. No. 71711-40 only), stone fruits (EPA 

Reg. No. 71711-40 only), snap beans, tree nuts, nonbearing deciduous fruit, tree nuts and vines, 

ornamentals, greenhouse cucumbers, and greenhouse tomatoes. 

Akari® 5SC Miticide/Insecticide (EPA Reg. No. 71711-4) was originally for ornamental and 

greenhouse use sites. The label still has a section for control of mites “on greenhouse 

cucumbers, greenhouse tomatoes, and greenhouse peppers, all ornamental crops including 

flowering and foliage crops, nursery crops, nonbearing fruit trees and vines, and Christmas trees. 

These include those crops grown in greenhouses, shade and lathe houses, outdoor nurseries and 

fields, and in interiorscapes.” However, all of the agricultural crops on the other two labels have 

been added to this label as well. 

Table 1 lists the maximum use patterns for the labeled use sites. Multiple table rows for the 

same crop and label indicate that the use site appears in multiple sections of the label. There are 

no label directions that resulted in ambiguous maximum use patterns. 
5 

Table 1. Maximum Use Patterns for Current Uses of Fenpyroximate

Use EPA Reg. No. Max. Sin

gle 

App. Rate 

(lbs a.i./A) A

Max. Annual 

App. Rate 

(lbs a.i./A) A

App. 

Interval 

(d) 

Application 

Type Additional A

Avocado, black sapote, canistel, mamey sapote, 

mango, papaya, sapodilla, and star apple 71711-4 

71711-19 71711-40

0.11 0.21 B

14 

Aerial or 

ground 

Do not use producaction in consecutDo not apply throusystem. Do not apply withwaters. Citrus: Do not appFL and TX. Citrus: For aerial uapply within 150 fCitrus, nonbearing Do not apply to cigreenhouses. Corn: Use on corn KS, NM, OK, and No. 71711-4). Pome: Do not appMiddle (ARM) sp

Citrus fruits (crop group 10-10) east of the 

Mississippi River 0.21 0.21 B

Citrus fruits (crop group 10-10) west of the 

Mississippi River 0.21 0.42 B

Citrus fruits (crop group 10-10) 

71711-19 H71711-40 H 0.21 0.42 B Ground only71711-40 H 0.21 0.21 B

Aerial or 

ground 

Cotton 

71711-4 

71711-19 71711-40

0.11 0.11 B

Cucumbers 

0.11 0.21 C Corn (field, pop, silage, and seed) 

Fruiting vegetables (crop group 8-10) 

Grapes (raisin, table, wine) 71711-4 71711-19 0.11 0.11 B

Ground only

Grapes (crop subgroup 13-07F) 71711-40

Low-growing berries (crop subgroup 

13-07G) except cranberries 

71711-4 

71711-19 71711-40

0.11 0.21 C

Hops 0.16 0.16 B

Melons (crop subgroup 9A) 0.11 0.21 C

Mint (peppermint, spearmint) 0.11 0.21 B 7 

Nonbearing deciduous fruit, tree nuts, and vines

0.11 0.11 B Ornamentals 14 

Pome fruits (crop group 11-10) 

Potato tuberous and corm vegetables (crop 

subgroup 1C) 71711-4 71711-40 0.11 0.21 C 7 Aerial or ground Stone fruits (crop group 12-12) 0.11 0.21 B, C 14 Ground only

Snap beans 

71711-4 

71711-19 71711-40

0.11 0.21 C 14 Aerial or ground 
6 

Use EPA Reg. No. Max. Single App. Rate (lbs a.i./A) A Max. Annual App. Rate (lbs a.i./A) A App. Interval (d) Application Type Additional A

Almonds and pistachios 71711-40 H

0.21 

0.42 B

14 

Ground only

Do not use producaction in consecutDo not apply throusystem. Do not apply withwaters. Greenhouse uses: Volume equipmen

Almonds and pistachios west of the Mississippi 

River 71711-4 

71711-19 71711-40 Tree nuts (crop group 14) west of the Mississippi River, excluding almonds and pistachios 0.21 B Tree nuts (crop group 14, excluding almonds and 

pistachios 71711-40 H

Tree nuts (crop group 14) and pistachios east of 

the Mississippi River 

71711-4 

71711-40

0.11 

0.11 B Not Tree nuts (crop group 14) and pistachios (all applicable 

geographies) 

71711-19 

71711-40 H

Greenhouse cucumbers 

71711-4 0.21 D One crop cycle Aerial or ground E

71711-19 71711-40

0.42 F 14, one crop cycle 

Ground only

Greenhouse tomatoes and greenhouse peppers 71711-4 Aerial or ground E

Greenhouse tomatoes 71711-19 71711-40 Ground only Ornamental trees, vines, shrubs, foliage, and 

flowering plants 71711-4 0.34 0.69 14 G

A Maximum annual application rates are whole multiples of maximum single application rates, all of which were rounded to two signiB The labeled application rate limit is given per growing season, which is interpreted as per year. C The labeled application rate limit is given per crop cycle. These crops are not typically planted more than once per year in the same 

Therefore, the application rate limits per crop cycle were used as annual rate limits. 

D The label allows only one application per growing season or crop cycle, but allows two applications per year. E Ground application is recommended but not required. F Two applications are allowed per crop cycle. Four applications are allowed per year. G The labeled application rate limit is given per crop cycle or growing season, whichever is longer, which is interpreted as per year. 

H This use pattern is from a supplemental label. 
7 

Figure 1 depicts a national-level summary of the estimated agricultural usage of fenpyroximate 

in 2011 (USGS, 2014). National agricultural usage of fenpyroximate has been increasing since 

2004, mostly on orchards. 

Figure 1. Agricultural Usage of Fenpyroximate in 2011 (USGS, 2014)
8 

4. Conclusions from Previous Risk Assessments 

a. Ecological Risk Assessment 

The Agency has conducted multiple ecological risk assessments on fenpyroximate over the past 

14 years that serve as a basis for this scoping document. The most recent full ecological risk 

assessment for proposed new uses of fenpyroximate is dated Mar. 21, 2012 (DP 394291). Two 

partial assessments followed within one year (DP 394367, 2012; DP 406242, 2013). Primary 

risk issues were chronic risk to mammals and birds, acute and chronic risk to fish (surrogates for 

aquatic-phase amphibians), acute risk to aquatic invertebrates, and risk to non-vascular aquatic 

plants (see Table 2), although some high-rate uses resulted in further risks. In addition, although 

fenpyroximate is categorized as practically non-toxic to adult honeybees, and by extension, to 

other beneficial terrestrial invertebrates on an acute exposure basis, there is considerable 

uncertainty regarding the potential effects of the compound on terrestrial invertebrates’ larval 

development and survival. The mode of action of fenpyroximate causes inhibition of molting of 

all immature stages, inhibits oviposition, and decreases feeding action. Therefore, risk was 

presumed for terrestrial invertebrates due to potential effects to larvae are not known, and 

additional data is needed to fully characterize the risk associated with fenpyroximate use to all 

developmental stages, as sensitivity may vary according to life-stage. 

Specifically, in recent risk assessments, proposed uses of fenpyroximate had the potential for 

direct adverse effects on listed and non-listed freshwater fish and aquatic-phase amphibians 

(based on acute and chronic exposure), listed freshwater and estuarine/marine invertebrates 

(based on acute exposure), listed freshwater invertebrates (based on chronic exposure), listed 

aquatic non-vascular plants, listed estuarine/marine fish and non-listed freshwater invertebrates 

(based on acute exposure), and listed and non-listed birds (surrogates for terrestrial-phase 

amphibians, and reptiles) and mammals (based on chronic exposure). Again risk to terrestrial 

invertebrates was presumed due to potential effects to the larval life-stage is not known; due to 

mode of action of fenpyroximate, causing inhibition of molting of all immature stages, inhibiting 

oviposition, and decreasing feeding action the sensitivity may vary according to life-stage. A 

summary of exceedances of the level of concern (LOC) is listed in Table 2. Figure 2 and Table 

3 summarize the potential risks and the supporting evidence. 

Table 2. LOC Exceedances for Recently Assessed Proposed Uses 

Effect 

Taxonomic Group 

Birds Mammals Terrestrial 

Plants 

Terrestrial 

Inverts Fish Aquatic Inverts 

Aquatic 

Plants 

Direct Effect LOC 

Exceedance √ √ -- √a √ √ √

Indirect Effect 

Potential √ √ √ √ √ √ √

a

 Risk presumed, potential effects to larvae are not known, and are considered to be an uncertainty due to the nature 

of the chemical.
9 

Figure 2. Graphic Summary of Potential Risks of Recently Assessed Proposed Uses 

Table 3. Evidence of Risk to Taxonomic Groups from Proposed Fenpyroximate Uses 

Greater Certainty of Negligible Risk Conclusion Greater Certainty of Potential for 

Environmental Impact 

Terrestrial Plants: All RQs < LOC. 

Aquatic Organisms: RQs > LOC (up to 5.0). 

Mammals & Birds: RQs > LOC (up to 9.8 for mammals 

and 1.3 for birds). 

Lower Certainty of Negligible Risk Conclusion Lower Certainty of Potential for Environmental 

Impact 

 Terrestrial Invertebrates: No toxicity observed in acute 

studies for adult life stages. Unknown/Presumed toxicity 

for larval life stages due to mode of action of chemical. 

b. Drinking Water Exposure Assessments 

The most recent full drinking water exposure assessment for proposed new uses of 

fenpyroximate is dated Jan. 23, 2012 (DP 391431). Two partial assessments followed in the 

same year (DP 392472; DP 404840). The residues of concern were the parent compound, M-1, 

and M-3. Maximum screening exposure estimates for the residues of concern were 43 μg/L (1-

in-10-year peak) and 8.6 μg/L (1-in-10-year annual mean) for surface water (based on a 

proposed use on cranberries) and ≤0.27 μg/L for ground water. 
10 

c. Clean Water Act Programs 

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 

fenpyroximate (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 fenpyroximate (see url: 

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

data submitted or otherwise located as part of the registration review process may be used to 

update aquatic life benchmarks if applicable. 

Fenpyroximate 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 fenpyroximate, 

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. 

5. Environmental Fate and Transport 

Fenpyroximate is a trans stereoisomer and a tert-butyl ester (chemical structure and name are in 

Table 4). The compound is relatively non-volatile, lipophilic, and slightly to hardly mobile in 

soil. Fenpyroximate degrades mainly via biodegradation in soil and water bodies (half-lives of 

23-41 days in aerobic and anaerobic systems). The compound is also rapidly photoisomerized to 

reach equilibrium with its cis isomer M-1 and photolyzed in shallow, illuminated water 

(fenpyroximate half-life of 1.5 hours; M-1 half-life of 10.5 hours). However, the importance of 

this degradation pathway is expected to be limited because fenpyroximate and its isomer are 

expected to partition to sediment in water bodies, where aqueous photolysis is limited. 

Fenpyroximate does not hydrolyze readily and may bioconcentrate in fish. 

Fenpyroximate is not expected to move to ground water in appreciable amounts but may move to 

surface water bodies via spray drift and runoff of residues sorbed to suspended sediment. Table 

4 summarizes the submitted chemical and environmental fate data for fenpyroximate. 
11 

Table 4. Chemical Properties and Environmental Fate Parameters of Fenpyroximate 

Parameter Value Source

Selected Physical/Chemical Parameters 

Molecular mass (molecular formula) 421.50 g/mol (C24H27N3O4) (Calculated) 

Vapor pressure (25 °C) 5.6 x 10-8 torr MRID 44781003 

Aqueous solubility (25C) pH 5: 0.023 mg/L pH 7: 0.026 mg/L 

pH 9: 0.034 mg/L 

MRID 44781003 

Henry’s Law Constant (25°C, pH 7) 1.2 x10-6 atm-m3/mol (Calculated) 

Log octanol-to-water partition coefficient 

(log KOW) 

5.01 MRID 44781003 

Dissociation constant (pKb) Not determined MRID 44781003 

Persistence in Water

Hydrolysis half-life (25C) pH 5: 180 d pH 7: 226 d 

pH 9: 221 d 

MRID 44847909 

Aqueous photolysis half-life (25C) 1.8 hrs (0.15 solar days) MRID 44781016 

Anaerobic aquatic metabolism half-life 

(25C) 

33 d MRID 45649707 

Aerobic aquatic metabolism half-life (20C) 23, 34 d MRID 47521406 

Persistence in Soil 

Soil photolysis half-life (25C) 24 d MRID 45649705 

Aerobic soil metabolism half-life (25°C) 28, 41 d MRID 45187901/ 

45649706 

39 d MRID 46158501 

Mobility

Freundlich organic carbon-normalized 

coefficients (KFOC) A

7,550; 18,600; 41,400; 44,000; 58,300 

L/kgOC

MRID 45649709 

Field Dissipation 

Terrestrial field dissipation half-life 1 d (German sandy silt loam), 

11 d (German sandy loam), 

12 (German loamy sand), 

24 d (German sandy loam) 

MRID 45649710/ 

45649711 

3.6 d (Commerce silt loam, AR), 

4.1 d (Cajon sandy loam, CA), 

15 d (Norfolk sandy loam, NC) 

MRID 45649712/ 

45734203 

Fish Bioconcentration 

Fish bioconcentration factors (steady-state, 

total residues); depuration half-life 

770-1100 (edible), 2800-4100 (inedible), 

1800-2700 (whole fish); 5.3 d 

MRID 48381102 

A The coefficient of variation for KFOC (0.60) was less than that for KF (1.4), indicating that sorption to organic 

carbon is important. 
12 

a. Transformation Products 

Fenpyroximate’s cis isomer M-1, its carboxylic acid M-3, and cleavage products M-6, M-8, M11, M-16, and carbon dioxide are its major transformation products (chemical names and 

structures are in Table 4. Figure 3 illustrates the transformation pathway of fenpyroximate in 

the environment. 

Major organic degradates of fenpyroximate (and M-1) tend to have higher mobility in soil than 

the parent compound (and its isomer). Mean KFOC values for M-3, M-8, and M-11 are 660, 90, 

and 611 L/kgOC (n=4; MRID 45649708 and 47521401). As expected for a carboxylic acid, M-3 

is orders of magnitude more soluble in water (solubility of ≥25 mg/L at 25°C; MRID 45649708) 

than fenpyroximate. 

It is uncertain whether unextracted residues in the laboratory studies were well sorbed to soil and 

not readily available because extraction solvents with a wide range of dielectric constants 

(including polar and nonpolar solvents) were not explored and concentrations of unextracted 

residues were up to 60% of the applied and displayed variable formation patterns (peaking prior 

to study termination in some systems and at study termination in others). Use of reflux, Soxhlet, 

and/or harsh extraction methods (using strong acids or bases) does not substitute for the use of 

multiple polar and nonpolar solvents. 

Unextracted residues appear to include degradates of fenpyroximate rather than the parent 

compound because the sterile system in MRID 47521406 did not produce appreciable amounts 

of unextracted residues (i.e., up to 1.3% of the applied) 105 days after treatment. This means 

that the uncertainty in the availability of the unextracted residues leads to uncertainty in the 

amounts of degradates formed, not uncertainty in the degradation rates of the parent compound. 
13 

Table 5. Fenpyroximate and Its Environmental Transformation Products 

Code Name/ Synonym Chemical Name Chemical Structure Study Type MRID M

%

PARENT

Fenpyroximate (E-isomer) 

IUPAC: tert-butyl (E)-α-(1,3-dimethyl-5-phenoxypyrazol-4-ylmethyleneaminooxy)-p-toluate CAS: 1,1-dimethylethyl 4-[[[(E)-[(1,3-dimethyl-5-phenoxy-1H-pyrazol-4-yl)methylene]amino]oxy]methyl]benzoate CAS No.: 134098-61-6 Formula: C24H27N3O4MW: 421.50 g/mol 

N

N

N

O

O

O

O

TRANSFORMATION PRODUCTS

M-1 (Z-isomer) 

tert-butyl (Z)-4-[(1,3-dimethyl-5-phenoxypyrazol-4-yl)methyleneaminooxymethyl]-benzoate Formula: C24H27N3O4MW: 421.50 g/mol

O

O

N

N

N

O

O

Hydrolysis 44847909 

Aq photolysis 44781016 

Soil photolysis 45649705 

Aerobic soil 45187901 

Anaerobic aquatic 45649707 

M-3 (E)-4-[(1,3-dimethyl-5-phenoxypyrazol-4-

yl)methylene-aminooxy-methyl]-benzoic acid Formula: C20H19N3O4MW: 365.39 g/mol N

N

N

O

OH

O

O

Hydrolysis 44847909 

Aq photolysis 44781016 

Soil photolysis 45649705 

Aerobic soil 46158501 Aerobic soil 45187901 

Anaerobic aquatic 45649707 

Aerobic aquatic 45734202/ 47521406 

Terrestrial field 45649710/ 45649711 1Terrestrial field 45649712/ 45734203 
14 

Code Name/ Synonym Chemical Name Chemical Structure Study Type MRID M

%

M-6 1,3-dimethyl-5-phenoxypyrazole-4-

carbaldehyde Formula: C12H12N2O2MW: 216.24 g/mol 

N

N

O

O

Aq photolysis 44781016 

Soil photolysis 45649705 

Aerobic soil 46158501 Aerobic soil 45187901 

Anaerobic aquatic 45649707 

M-8 1,3-dimethyl-5-phenoxypyrazole-4-

carboxylic acid Formula: C12H12N2O3MW: 232.24 g/mol 

N

N

O

O

OH Soil photolysis 45649705 

Aerobic soil 46158501 Aerobic soil 45187901 

Anaerobic aquatic 45649707 

Aerobic aquatic 45734202/ 47521406 

M-11 1,3-dimethyl-5-phenoxypyrazole-4-

carbonitrile Formula: C12H11N3O MW: 213.24 g/mol 

N

N

O

N Aq photolysis 44781016 

Aerobic soil 46158501 Aerobic soil 45187901 

Anaerobic aquatic 45649707 

Aerobic aquatic 45734202/ 47521406 

M-16 4-hydroxymethylbenzoic acid 

Formula: C8H8O3

MW: 152.15 g/mol 

HO

OH

O Aerobic soil 46158501 

Aerobic soil 45187901 

Anaerobic aquatic 45649707 

UNK-1 Unidentified photodegradate UNK-1 Not identified Soil photolysis 45649705 PS-6 Unidentified biodegradate Not identified Aerobic aquatic 45734202/ 47521406 
15 

Code Name/ Synonym Chemical Name Chemical Structure Study Type MRID M

%

Unextracted residues 

Not applicable 

Not applicable 

Soil photolysis-light 45649705 

Soil photolysis-dark 

Aerobic soil-sandy 

loam 46158501

Aerobic soil-sand 

45187901

Aerobic soil-sand 

Anaerobic aquatic 45649707 

Aerobic aquatic-river 45734202/ 

47521406

Aerobic aquatic-pond 

Carbon dioxide Carbon dioxide 

Formula: CO2

MW: 44.1 g/mol O O

Soil photolysis 45649705 

Aerobic soil 46158501 Aerobic soil 45187901 

Anaerobic aquatic 45649707 

Aerobic aquatic 45734202/ 47521406 
16 

Figure 3. Environmental Transformation Route of Fenpyroximate (MRID 45187901, p 52)
17 

6. Receptors 

Fenpyroximate is very highly toxic to freshwater and estuarine/marine fish and invertebrates on an 

acute exposure basis. The M-3 degradate of fenpyroximate is moderately toxic to freshwater fish 

and invertebrates on an acute exposure basis. No toxicity data is currently available for the M-1 

degradate of fenpyroximate; however this is not considered to be a data gap. Reductions in length, 

dry weight and survival (immobile neonates and F0 mysids) were noted effects resulting from 

chronic exposure of fenpyroximate to freshwater fish, freshwater invertebrates, and 

estuarine/marine invertebrates (recently reviewed), respectively. However, the reported NOAEC 

from the mysid life-cycle study is uncertain because it does not necessarily account to effects to 

offspring; no information was measured or recorded for the second generation mysids. As a result 

the submitted study does not fulfill guideline requirements and there are key reproductive 

endpoints missing. In addition, preliminary results from the recently submitted and reviewed fish 

full life-cycle study with freshwater fish indicates a significant reduction in eggs per spawn, and 

delays in time to hatch observed for the F1 generation in the second lowest test concentration. 

Preliminary results from recently submitted and reviewed 10-day sediment toxicity study with the 

Midge (Chironomus tentans) indicated that the LC50 and EC50 values were empirically 

determined to be greater than the highest test level in both endpoints. Toxicity values were based 

on all three strata concentrations (i.e., sediment, pore water, and overlying water), including 

concentrations normalized for TOC (2.1%). Aquatic plant toxicity testing indicated that vascular 

plants, e.g., duckweed (Lemna gibba) are not sensitive to fenpyroximate at the concentrations 

tested, whereas, non-vascular plants, e.g., marine diatoms (Skeletonema costatum) and green algae 

(Scendesmus suspicatus) are sensitive to fenpyroximate at the concentrations tested, based on 

effects on cell density. 

Fenpyroximate is practically non-toxic to young adult honey bees and birds, and moderately toxic 

to mammals on an acute exposure basis. However, mortality and sublethal effects were both 

observed in the subacute dietary toxicity study for mallard ducks. Although mortality was 

observed it was less than 50% in all treatment levels (three total); however, clinical signs of 

toxicity were observed in all treatment groups (for a majority of the birds) up to 7 days after 

dosing. Reductions in female body weight gain in birds and decreased parental and pup weight in 

mammals were noted effects resulting from chronic exposure of fenpyroximate. Tier II terrestrial 

plant testing using both seedling emergence and vegetative vigor assays indicated that neither 

monocotyledonous nor dicotyledonous plants are sensitive to fenpyroximate at the application rate 

tested. 

Table 6 provides a summary of the most sensitive ecological toxicity endpoints of aquatic 

organisms for both the parent compound fenpyroximate and degradate M-3, and Table 7

summarizes the most sensitive endpoints of terrestrial organisms for both the parent compound 

fenpyroximate and degradate M-3. 
18 

a. Effects to Aquatic Organisms 

Table 6. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for 

Fenpyroximate and Degradate M-3 

Aquatic Animals 

Species 

Test 

Substance 

(% a.i.) 

Acute Toxicity Chronic Toxicity 

96-hr LC50/EC50

(95% CI) 

(μg a.i./L) 

(Toxicity 

Classification) 

48-hr EC50 

(95% CI) 

(μg a.i./L) 

(Toxicity 

Classification)

MRID 

(Study 

Classification)

NOAEC/ 

LOAEC 

(μg a.i./L) 

(Endpoints) 

MRID 

(Study 

Classification)

Rainbow trout 

(Oncorhynchus 

mykiss) 

TGAI 

98.8% 

0.73 (0.59-1.3) 

 (very highly toxic) -- 46799201 (Acceptable) ND ND 

EP 

5.2% 

0.44 (0.37-0.57) 

 (very highly toxic) -- 47098102 

(Acceptable) ND ND 

M-3 

metabolite 

6200 (3000-28000) 

 (moderately toxic) -- 46974402 (Supplemental) ND ND 

Fathead 

minnow 

(Pimephales 

promelas) 

TGAI 

98.6% 

ND -- ND

0.11/0.23 

(length) 

 45649808 

(Acceptable; 

850.1400) 

TGAI 

97.2% 

0.016/0.031 

(Spawn per 

female & F1 time 

to hatch) 

48735301 

(Preliminary 

Review; 

850.1500) 

Sheepshead 

Minnow 

(Cyprinodon 

variegates)

TGAI 

98.8% 

36 (17-71) 

(very highly toxic) -- 47098101 (Acceptable) ND1

 ND1

Waterflea 

(Daphnia 

magna)

TGAI 

99.35% --

3.6 (2.9-4.6) 

 (very highly 

toxic) 

44781015 

(Acceptable) 

<0.17/0.17 

 (dry weight) 

& 

0.56/1.0 

(immobile 

neonates) 

47098103 

(Acceptable) 

EP 

5.2% -- 

1.6 (1.3-2.0) 

 (very highly 

toxic) 

46800801 

(Acceptable) ND ND 

M-3 

metabolite -- 

13050 

(9500-20000) 

 (moderately 

toxic) 

46974401 

(Acceptable) ND ND 

Eastern oyster 

(Crassostrea 

virginica)

TGAI 

98.8% -- 

3.3 (1.6-6.7) 

 (very highly 

toxic) 

 47021401 

(Acceptable) -- -- 

Mysid 

(Americamysis 

bahia) 

TGAI 

98.8% 

3.7 (2.2-7.7) 

 (very highly toxic) -- 45649804 (Acceptable) 

1.46/4.58 

(F0 Day-15 & 

Day-32 survival) 

47521405 

(Supplemental)2
19 

Aquatic Animals 

Species 

Test 

Substance 

(% a.i.) 

Acute Toxicity Chronic Toxicity 

96-hr LC50/EC50

(95% CI) 

(μg a.i./L) 

(Toxicity 

Classification) 

48-hr EC50 

(95% CI) 

(μg a.i./L) 

(Toxicity 

Classification)

MRID 

(Study 

Classification)

NOAEC/ 

LOAEC 

(μg a.i./L) 

(Endpoints) 

MRID 

(Study 

Classification)

Midge 

(Chironomus 

tentans) 

TGAI 

99.8% ND ND ND 

10-day 

EC50:

0.624 μg 

TTR/L 

NOAEC: 0.400 

μg TTR/L 

LOAEC: 0.624 

μg TTR/L 

(Growth) 

48381101 

(Preliminary 

Review; 

850.1735; based 

upon meanmeasured 

overlying water 

concentrations)

Aquatic Plants 

Species Test 

Substance Endpoint (μg a.i./L) Effect (MRID; Study Classification) 

Duckweed 

(Lemna gibba) 

EP 

5.1% 

7-day EC50 >190 

NOAEC = 31 

Frond number 

 (45649811; acceptable) 

Marine Diatom 

(Skeletonema 

costatum) 

EP 

5.1% 

96 hr EC50 = 1.9 

NOAEC = 0.26 

Cell density 

(45649815; acceptable) 

Green alga 

(Scendesmus 

suspicatus) 

TGAI 

99.4% 

72 hr EC50 = 0.66 

NOAEC <1.8 

Cell density 

(45649816; supplemental)3

EP = End-Use Product; ND = No data; -- = not applicable 

1

 No chronic estuarine/marine fish toxicity data is available. 

2

 The NOAEC is uncertain because it does not necessarily account to effects to offspring. 

3

 A preferred test species was not used, and the study was conducted for 72-hrs and not the recommended 96-

hrs. 

b. Effects to Terrestrial Organisms 

Table 7. Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for 

Fenpyroximate 

Terrestrial Animals 

Species/ 

Test 

substance 

(% a.i.) 

Acute Toxicity Chronic Toxicity 

48-hr LD50 

(μg a.i./bee) 

14-day LD50

(95% CI) 

(mg/kg-bw) 

(Toxicity 

Classification)

13-day LC50

(mg a.i./kg-diet 

(ppm)) 

(Toxicity 

Classification)

 MRID 

(Study 

Classification)

NOAEC/LOAEC

(mg a.i./kg-diet 

(ppm)) 

(Endpoints) 

 MRID 

(Study 

Classification) 

Bobwhite Quail 

(Colinus 

virginianus)/ 

(TGAI; 99%) 

-- 

>2000 

 (practically 

non-toxic) 

>50001 

(practically 

non-toxic) 

 45649715 

(Acceptable) 

& 

44847908 

(Acceptable) 

≥ 255 

(no effects) 

47521404 

(Supplemental)2
20 

Terrestrial Animals 

Species/ 

Test 

substance 

(% a.i.) 

Acute Toxicity Chronic Toxicity 

48-hr LD50 

(μg a.i./bee) 

14-day LD50

(95% CI) 

(mg/kg-bw) 

(Toxicity 

Classification)

13-day LC50

(mg a.i./kg-diet 

(ppm)) 

(Toxicity 

Classification)

 MRID 

(Study 

Classification)

NOAEC/LOAEC

(mg a.i./kg-diet 

(ppm)) 

(Endpoints) 

 MRID 

(Study 

Classification) 

Mallard Duck 

(Anas 

platyrhynchos)/ 

(TGAI; 99%) 

-- 

>2000 

 (practically 

non-toxic) 

>50001 

(practically 

non-toxic) 

45649714 

(Acceptable) 

& 

45649716 

(Acceptable) 

35 / 182 

(reductions in 

female body 

weight gain) 

 45649718 

(Supplemental)3

≥ 255 

(no effects) 

47521403 

(Supplemental)2

Laboratory rat 

(Ratus 

norvegicus)/ 

(TGAI; 98 & 

97.3%) 

-- 

245 (167-323) 

(moderately 

toxic) 

-- 43560501 

(Acceptable) 

30/1004

(decreased 

parental and pup 

weight) 

43429506 

(Acceptable) 

Laboratory rat 

(TGAI; 88.7%) -- Inhalation LC50 = 0.24 mg/L (Males) (Toxicity category II) 

44847903 

(Acceptable) -- -- 

Honey Bee 

(Apis mellifera)/ 

(EP; 5.2%; acute 

contact) 

>479.8 

(practically 

non-toxic) 

-- -- 45649818 

(Acceptable) -- -- 

Terrestrial Plants 

Species/ 

Test 

substance 

(% a.i.)

Seedling Emergence Vegetative Vigor

MRID Study 

EC Classification 25

(lb a.i./acre) 

NOAEC 

(lb a.i./acre) 

EC25

(lb a.i./acre) 

NOAEC 

(lb a.i./acre) 

All plants 

tested / 

(EP; 5.2%) 

>0.30 0.30 

(no effects) >0.30 0.30 (no effects) 

45649809; 

45649810 

Acceptable; 

Acceptable 

EP = End-Use Product; ND = No data; -- = not applicable 

1

 5 days of exposure via the diet, followed by 8 days of observation of chemical free diet; however, clinical 

signs of toxicity, body weight reductions and decreased food consumption were observed in all treatment 

levels. Mortality was observed in two test concentrations, but was <50%. 

2 At this time a new study is not required as the residue values at this time are below the level that would 

result in chronic effects. However, if the label is adjusted in the future, the study may not be adequate to 

evaluate risk to birds. 

3

 Animals used were 51 weeks of age and laid eggs 3 weeks into the study. 

4

 30 ppm a.i. = 1.99 mg a.i./kg-body wt/day for males and 2.44 mg a.i./kg-body wt/day for females; 100 

ppm a.i. = 6.59 mg a.i./kg-body wt/day for males and 8.60 mg a.i./kg-body wt/day for females 

c. Ecological Incidents 

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

incidents that have been reported to the Agency. When available, EIIS includes 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 
21 

(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. The Aggregate Incident Reports database is an Agency database that 

may contain minor wildlife and plant incidents for chemicals. 

As of August 12, 2014 no ecological incidents involving fenpyroximate were identified in EIIS, 

AIMS or the aggregate incident database. Incident databases will be reviewed again at the time of 

the risk assessment. 

7. Exposure Pathways of Concern 

The conceptual model will consider the parent compound and its degradates (M-1 and M-3) for the 

drinking water exposure assessment; whereas for the ecological risk assessment the residues of 

concern are the parent compound and the M-1 degradate. 

The environmental fate properties and use patterns of fenpyroximate indicate that direct spray, 

spray drift, and runoff represent potential transport mechanisms to aquatic and terrestrial 

organisms. Drinking water and inhalation exposure pathways were screened using the SIP 

(Screening Imbibition Program, version 1.0) and STIR (Screening Tool for Inhalation Risk, 

version 1.0) screening methods and were found to be exposure pathways of low concern (no LOC 

exceedances are expected; outputs for each model are located in Appendix A). SIP and STIR are 

described in detail at: http://www.epa.gov/oppefed1/models/terrestrial/index.htm. 

8. Analysis Plan 

a. Stressors of Concern 

i. Ecological Risk Assessment 

Fenpyroximate, M-1, and M-3 are the residues of concern for mammals (and other terrestrial 

organisms, by extension). Due to structural similarity and lack of toxicity data, the residues of 

concern for mammals are assumed to have equivalent toxicity (USEPA, 2003). 

Acute ecotoxicity data indicate that M-3 is four orders of magnitude less toxic than the parent 

compound to fish and aquatic invertebrates (MRIDs 46974401 and 46974402). Due to the large 

difference in acute toxicity between fenpyroximate and M-3 to aquatic animals, M-3 is also 

considered to be less toxic to aquatic animals on a chronic exposure basis and less toxic to aquatic 

plants. Therefore, the residues of concern for aquatic organisms are fenpyroximate and its cis

isomer M-1, which are assumed in the lack of data to have equivalent toxicity. 

ii. Drinking Water 

The drinking water assessments conducted to support the registration review human health risk 

assessments of fenpyroximate will incorporate model estimates of fenpyroximate residues of 

concern, which are parent compound, M-1, and M-3 (USEPA, 2003), in surface and ground waters 

using the total residues of concern (TR) modeling approach. Unextracted residues may be 

included if additional information (e.g., solvent exploration) indicates that the unextracted residues 

in MRIDs 45187901 and 46158501 are not well sorbed to soil or if additional information are not 
22 

available. Current exposure models, currently including SWCC and PRZM-GW, will be used. 

The fenpyroximate residues of concern may be reevaluated pending receipt and review of 

additional environmental fate and toxicity data for fenpyroximate and its degradates. 

b. 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/oppefed1/models/water/index.htm and 

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

Screening level calculations have suggested that drinking water and inhalation exposure pathways 

are likely not of concern (Appendix A). These exposure pathways will not be considered at the 

time of the risk assessment. 

i. Available Monitoring Data 

The Agency is not aware of monitoring conducted by federal and state agencies for fenpyroximate, 

as of May 21, 2014. Monitoring will be considered in the assessment to the extent that data on 

fenpyroximate are available. 

c. Measures of Effect 

Toxicity data presented in Section 3 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, 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. 

Initial searches of the ECOTOX database has identified literature highlighting potential interaction 

of fenpyroximate and other pesticides within hives, resulting in increased toxicity of 

fenpyroximate toxicity to bees relative to toxicity of the compound alone. The risk assessment 

will consider all available information, including open literature, examining potential uncertainties 

surrounding and evaluating potential exposure and risk to various taxa of concern including 

pollinators. Additional information is needed, but uncertainty associated with risks to bees needs to 

be evaluated with more data to different life stages. Open literature data may address some 

uncertainties. 

9. 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. 
23 

10. 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), diclofop-methyl 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 of chemicals 

identified for EDSP screening was published on June 14, 2013 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. 

Fenpyroximate was not included in either the first or second list of chemicals issued an order to 

conduct Tier 1 EDSP testing. 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, 

visit the website, http://www.epa.gov/endo/. 

11. Preliminary Identification of Data Gaps 

a. Environmental Fate

Table 8 and Table 9 identify environmental fate studies by MRID that offer data for each 

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

in order to support risk assessment. 
24 

Table 8. Submitted Environmental Fate Data for Fenpyroximate 

OCSPP 

Guideline Data Requirement Submitted Studies (MRID)

Study 

Classifications

Sufficient 

for risk 

assessment?

Current Additional Data Need 

835.2120 Hydrolysis 44847909 Acceptable Yes — 

835.2240 Aqueous photolysis 44781016 Acceptable Yes — 

835.2410 Soil photolysis 45649705 Acceptable Yes — 

835.4100 Aerobic soil 

metabolism 

44781017 Unacceptable 

No 

Depending on whether the soils in 

MRID 45187901 are similar to 

domestic soils where fenpyroximate 

may be used, studies on 1-3 

additional soils are needed (see p. 25 

for discussion). 

44847910 Unacceptable 

45187901/ 

45649706 Upgradeable 

46158501 Supplemental 

835.4200 Anaerobic soil 

metabolism (None) (Not 

applicable) Yes — 

835.4300 Aerobic aquatic 

metabolism 47521406 Supplemental Yes — 

835.4400 Anaerobic aquatic 

metabolism 45649707 Acceptable No 

A guideline-compliant study of one 

sediment and its associated water is 

needed. 

835.1230 

835.1240 

Adsorption/ 

desorption and 

leaching 

44781018 Unacceptable 

Yes — 

44781019 Unacceptable 

44781020 Unacceptable 

44847911 Unacceptable 

45649709 Supplemental 

835.6100 Terrestrial field 

dissipation 

45649710/ 

45649711 Supplemental 

Yes 

The field studies are not acceptable, 

in part, because the storage stability 

data are inadequate. However, 

additional studies are not expected to 

change assessment conclusions. 

45649712/ 

45734203 Supplemental 

850.1730 Fish 

bioconcentration 

45649713 Supplemental No A guideline-compliant study with 

48381102 Supplemental two test concentrations is needed. 

850.6100 Analytical method 

in soil 45649915 Upgradeable 

No ILV reports are needed to upgrade 

MRIDs 45649914 and 45649915. 

Analytical method 

in water 45649914 Upgradeable 

Analytical method 

in freshwater 46847201 Unacceptable 

Table 9. Submitted Environmental Fate Data for Degradates of Fenpyroximate 

OCSPP 

Guideline 

Data 

Requirement Degradates Submitted Studies (MRID)

Study 

Classifications

Sufficient for 

risk assessment? 

Current Additional Data 

Need 

835.1230 Adsorption/ 

desorption 

M-3 45649708 Acceptable Yes — M-8, M-11 47521401 Supplemental 

Aerobic Soil Metabolism 

Soil taxonomy information for the studied soils in MRID 45187901 are needed. If this information 

indicates that the soils are not comparable to domestic soils where fenpyroximate is used, then the 

study will be unacceptable and a new aerobic soil metabolism study should include three soils. If 

soil taxonomy information indicates that the two soils are similar to domestic soils where 

fenpyroximate is used, then a new aerobic soil metabolism study of only one soil will be needed. 
25 

It is uncertain whether unextracted residues in the laboratory studies were well sorbed to soil and 

not readily available because extraction solvents with a wide range of dielectric constants 

(including polar and nonpolar solvents) were not explored and concentrations of unextracted 

residues were up to 60% of the applied and displayed variable formation patterns (peaking prior to 

study termination in some systems and at study termination in others). Use of reflux, Soxhlet, 

and/or harsh extraction methods (using strong acids or bases) does not substitute for the use of 

multiple polar and nonpolar solvents. 

Unextracted residues appear to include degradates of fenpyroximate rather than the parent 

compound because the sterile system in MRID 47521406 did not produce appreciable amounts of 

unextracted residues (i.e., up to 1.3% of the applied) 105 days after treatment. This means that the 

uncertainty in the availability of the unextracted residues leads to uncertainty in the amounts of 

degradates formed, not uncertainty in the degradation rates of the parent compound. Therefore, 

this issue is relevant to drinking water exposure assessment, not to ecological risk assessment. 

Information is needed to demonstrate that a range of nonpolar and polar extraction solvents do not 

substantially reduce the unextracted residue concentrations at a latter sampling interval at or near 

study termination when unextracted residues are at least >20% of the applied in one of the aerobic 

soil metabolism studies. Informal (non-GLP-compliant) documentation of solvent exploration 

may suffice rather than a new aerobic soil metabolism study. If the solvent exploration indicates 

directly or by inference that the unextracted residues in MRIDs 45187901 and 46158501 are well 

sorbed to soil, their kinetics half-lives will be less than otherwise. If the solvent exploration 

indicates that the unextracted residues in MRIDs 45187901 and 46158501 are not well sorbed to 

soil, then the unextracted residues may be considered available residues of concern and included in 

the kinetics half-life calculations for drinking water exposure assessment. 

Anaerobic Aquatic Metabolism 

Anaerobic aquatic metabolism information are available for only one sediment:water system. A 

study of a second sediment and its associated water is needed to reduce uncertainty in the 

environmental fate of fenpyroximate in suboxic waters. 

Fish Bioconcentration 

Additional fish bioconcentration data are needed due to the deficiencies noted in MRID 45649713 

and MRID 48381102. Among other deficiencies, both MRID 45659713 and 48381102 were 

conducted with only one test concentration. Two test concentrations need to be studied 

concurrently in a fish bioconcentration study to characterize the uptake and depuration kinetics. 

Given that fenpyroximate has already been shown to bioconcentrate to a degree that could be of 

concern, the additional information provided by testing two concurrent test concentrations will be 

important to risk assessment. This study should include two test concentrations, should not 

include a solvent, should identify and quantify any transformation products of the test compound, 

and should meet the other guideline criteria for conducting an acceptable study. 

Independent Laboratory Validations 

The submitted analytical methods in water and soil (MRIDs 45649914 and 46549915) are not 

acceptable without independent laboratory validation (ILV) reports indicating that they are 

reproducible, accurate, and precise at the stated limits of quantitation (LOQ). Rather than submit 
26 

ILV reports for the submitted methods, submission is encouraged of new, state-of-the-art methods 

(and associated ILV reports), typically using LC/MS/MS equipment, that can be performed with 

the least amount of cost and effort. It is also recommended to base the submitted methods on any 

existing multi-residue methods. The LOQs for the submitted methods are less than toxicological 

levels of concern for aquatic organisms and terrestrial plants. Therefore, if new methods are 

submitted, their LOQs need not be lower. 

E-fate Data Gap Summary 

In summary, an aerobic soil metabolism study (OCSPP Guideline 835.4100) of one to three soils 

with adequate extraction efforts is needed. The number of soils tested depends on whether MRID 

46158501 is upgraded with soil taxonomy data relating the soils to domestic soils. An anaerobic 

aquatic metabolism study (OCSPP Guideline 835.4400) of one sediment:water system is needed. 

A fish bioconcentration study (OCSPP Guideline 850.1730) is needed. And ILVs (OCSPP 

Guideline 850.6100) of the submitted analytical methods in soil and water are needed. However, 

new, state-of-the-art methods and associated ILV reports may be (and are encouraged to be) 

submitted rather than ILV reports for the submitted analytical methods. 

b. Effects 

Table 10 and Table 11 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. 

For the degradate M-3, toxicity data are available for acute freshwater fish and invertebrates (see 

Table 12). No toxicity data is currently available for the M-1 degradate of fenpyroximate, and no 

toxicity data will be requested. A cursory look at the modeling indicated that the conducting of 

these studies to demonstrate that M-1 degradate was less toxic would not provide substantive 

changes to the risk assessment because it is a major degradate only from degradation from 

photolysis, which is a minor degradation pathway in PRZM/EXAMS modeling. Therefore, 

exposure to the M-1 degradate is expected to be negligible. Therefore, the data for M-3 are 

sufficient for the registration review risk assessment for fenpyroximate. 

Table 10. Submitted Aquatic Ecological Effects Data for Fenpyroximate 

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study Classifications 

Are data 

needed to 

conduct 

risk 

assessment? 

Comments 

 850.1010 

Freshwater 

invertebrate 

acute toxicity 

44781015 Acceptable 

No None 

46800801* Acceptable 

850.1025 

850.1035 

850.1045 

850.1055 

Saltwater 

invertebrate 

acute toxicity 

45649804 Acceptable 

No None 45649806 Invalid 

47021401 Acceptable 

 850.1075 44781014 Supplemental No 
27 

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study Classifications 

Are data 

needed to 

conduct 

risk 

assessment? 

Comments 

Freshwater fish 

acute toxicity 45477201 Addendum #1 to 

44781014 

With a review of the addendums 

associated with 44781014 & 4569803 

(45477201 (DP, 46188801 (DP332653) 

& 47021402 (DP336524), respectively) 

the risk conclusions would not change 

as the endpoint values in these studies 

are less sensitive than the acceptable 

toxicity data for freshwater fish 

47098102 (EUP = 0.44 ppb) & 

46799201 (TGAI = 0.73 ppb). 

45649721 Acceptable 

45649801* Acceptable 

45649803 Supplemental 

46188801 Addendum #2 to 

44781014 

46799201 Acceptable 

47021402 Addendum to 

45649803 

47098102* Acceptable 

 850.1075 Saltwater fish 

acute toxicity 

45649805 Invalid 

46188802 Supplemental No None 

47098101 Acceptable 

 850.1300 

Freshwater 

invertebrate 

life cycle 

47098103 Acceptable 

No 

With a review of the addendum 

associated with MRID 45649807 

(46188804 under DP332653) the risk 

conclusion would not change as the 

endpoint value in this study is slightly 

less sensitive than the acceptable 

chronic toxicity data for daphnids 

MRID 47098103 (TGAI NOAEC = 

0.68 ppb vs. 0.56 ppb (from the 

acceptable study)). 

45649807 Invalid 

46188804 Addendum to 

45649807 

 850.1350 

Saltwater 

invertebrates 

life cycle 

47521405 Supplemental YES Data is needed; See explanation 

below

 850.1400 Freshwater fish 

early-life stage 

45649808 Supplemental 

No 

The DER reported that the stability of 

fenpyroximate the test systems was not 

sufficiently verified. Only at the highest 

concentration were both LSC and 

HPLC/RAM analyses performed, and 

HPLC/RAM analyses revealed that 

fenpyroximate accounted for only 53 to 

89% of the applied radioactivity. Since 

HPLC/RAM results were not consistent 

with LSC results, it is unclear if 

fenpyroximate degraded in the test 

systems, was limited by solubility, or if 

some other factor was involved. This 

deviation affects the acceptability of 

the study. The submitted information in 

the addendum does provide a logical 

and scientifically based argument 

support for the registrant’s argument. 

Although, the information provided 

does not upgrade the study; no 

additional data is needed.

46188803 Addendum to 

45649808 
28 

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study Classifications 

Are data 

needed to 

conduct 

risk 

assessment? 

Comments 

 850.1400 Saltwater fish 

early-life stage 

None; No 

data N/A – No data No 

No chronic data. However, freshwater 

fish are two orders of magnitude more 

sensitive on acute basis than 

estuarine/marine fish and on a chronic 

basis it is likely we already have the 

most sensitive fish species. Freshwater 

fish data can be used as a conservative 

estimate of fish toxicity. Therefore, no 

additional resources to conduct a study 

with estuarine/marine fish is needed. 

 850.1500 Fish full lifecycle 48735301 In Review In Review; 

No 

The study was submitted in response to 

a data requirement from a previous 

registration action. Preliminary review 

of the study suggests that it may be 

usable within the fenpyroximate risk 

assessment. However, a more refined 

analysis of the data is being completed 

to determine the scientific soundness 

and usability of the study within the 

risk assessment.

850.1735

Freshwater 

invertebrate – 

acute sediment 

toxicity

48381101 In Review In Review; 

No

The study was submitted in response to 

a data requirement from a previous 

registration action. While, a more 

refined analysis of the data will be 

completed to determine the scientific 

soundness of the study for use within 

the risk assessment, based on a 

preliminary review, suggests that it 

may be usable within the 

fenpyroximate risk assessment. 

Nonguideline 

Freshwater 

invertebrate – 

chronic 

sediment 

toxicity 

46847202 Invalid No 

Based on a preliminary review of the 

data, no effects were observed in the 

10-day Midge (Chironomus tentans) 

study using spiked sediment and 

therefore no additional sediment 

toxicity data is needed. 

850.4400 

Aquatic plant 

Toxicity Test 

using Lemna 

spp. 

45649811 Acceptable No None 

850.4500 Algal toxicity 

45649812 Acceptable 

No None 

45649814 Acceptable 

45649815 Acceptable 

45649816 Supplemental 

45649817 Supplemental 

850.4550 Cyanobacteria 45649813 Acceptable No None 

*Formulated product exposure. 
29 

Table 11. Submitted Terrestrial Ecological Effects Data for Fenpyroximate

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications 

Are data 

needed for 

risk 

assessment? 

Comments 

 850.2100 Avian oral toxicity 

45649714 Acceptable 

Yes 

Passerine species - acute oral 

toxicity study is not available. 

Chemical is practically non-toxic; 

however, clinical signs of toxicity, 

body weight reductions and 

decreased food consumption were 

observed in all treatment levels in 

the mallard duck subacute dietary 

study. Mortality was observed in two 

test concentrations, but was <50%, 

see discussion below.

45649715 Acceptable 

 850.2200 Avian dietary 

toxicity 

 44847908 Acceptable 

No None 

45649716 Acceptable 

 850.2300 Avian 

reproduction 

45649717 

Supplemental 

(range finder for 

45649718) 

No 

At this time a new study is not 

required as the residue values at this 

time are below the level that would 

result in chronic effects. However, 

if the label is adjusted in the future, 

the study may not be adequate to 

evaluate risk to birds. The mallard 

duck study used birds that were 51 

weeks of age and laid eggs 3 weeks 

into the study. 

45649718 Supplemental 

45649719 Supplemental 

45649720 N/A 

(see comments) 

 47521403 Supplemental 

 47521404 Supplemental 

Nonguideline Avian inhalation None N/A No None 

 850.3020 Honeybee acute 

contact toxicity 45649818* Acceptable No None 

OECD 213 Honeybee acute 

oral toxicity 45649819 Supplemental No None 

OECD 237 Honeybee larval 

acute toxicity No data N/A YES Data is needed; See explanation 

below 

Nonguideline Honeybee larval 

chronic toxicity No data N/A YES 

Data is needed; See explanation 

below, protocol submission 

required prior to study initiation 

Nonguideline Honeybee adult 

chronic toxicity No data N/A YES 

Data is needed; See explanation 

below, protocol submission 

required prior to study initiation

850.3030 Honeybee residue 

on foliage None N/A No Chemical is practically non-toxic. 
30 

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications 

Are data 

needed for 

risk 

assessment? 

Comments 

OECD 75 Semi-field testing 

for pollinators None N/A YES1 

1 Dependent on the results of the 

lower Tier 1 effects studies. 

Higher tier studies are recommended 

if the ratio of the EEC and larval or 

adult bee acute LD50>0.4 or the 

ratio of the EEC and the chronic 

NOAEC>1. Incident data and/or 

compelling open literature studies 

can also be used to support the need 

for higher tier studies. 

 850.3040 Field testing for 

pollinators None N/A YES1 

850.6200/ 

OECD 207 

Sub-chronic 

exposure to 

earthworms 

45649820 Supplemental 

Not 

applicable None 

Nonguideline 

Predatory mite 

acute contact 

toxicity 

45649821* Supplemental 

Green lacewing 

acute contact test 45649822* Supplemental 

Ladybug acute 

oral and contact 

test 

45649823* Supplemental 

Predacious thrips 

acute contact 

toxicity 

45649824* Supplemental 

Beneficial 

arthropods- acute 

contact toxicity 

45649825* Supplemental 

Predatory wasp 

(Aphidius 

rhopalosiphi), 

extended residue 

study 

48735302 In review No 

The study was submitted in response 

to a data requirement from a 

previous registration action. The 

study is currently in review, and the 

scientific soundness nor study 

classification are not known. 

However, additional data will not be 

needed to conduct the risk 

assessment. 

850.4100 

Seedling 

Emergence and 

Seedling Growth 

45649809 Acceptable No None 

850.4150 Vegetative Vigor 45649810 Acceptable No None 

*Formulated product exposure. 
31 

Table 12. Aquatic Ecological Effects Data for the Fenpyroximate Degradate, M-3 

OCSPP 

Guideline 

Data 

Requirement 

Submitted 

Studies 

(MRID) 

Study 

Classifications 

Are data needed 

for risk 

assessment? 

Comments 

 850.1010 

Freshwater 

invertebrate 

acute toxicity 

46974401 Acceptable No Toxicity data was submitted for 

the M-3 degradate only. 

 850.1075 Freshwater fish 

acute toxicity 46974402 Supplemental No Toxicity data was submitted for the M-3 degradate only. 

Freshwater Fish Full-Life Cycle Toxicity (Still in Review) 

A study was received by the Agency evaluating toxicity to freshwater fish looking at the fish full 

life-cycle, and it is currently under review. Until the review is finalized, potential risk to 

freshwater fish on a chronic exposure basis remains an uncertainty. A more thorough analysis of 

the data will be completed to determine the scientific soundness of the study for use within the risk 

assessment; however, initial review of the study suggests that it may be usable within the 

fenpyroximate risk assessment. 

Sediment-Dwelling Invertebrate Toxicity (Still in Review) 

 

A study was received by the Agency regarding toxicity to sediment-dwelling organisms and is 

currently under review. Preliminary review of the study suggests that it may be usable within the 

fenpyroximate risk assessment. 

Estuarine/Marine Fish Early Life-Stage Toxicity Study 

Although no chronic toxicity data to evaluate the risks to estuarine/marine fish is available, 

freshwater fish are two orders of magnitude more sensitive on acute basis than estuarine/marine 

fish and on a chronic basis it is likely we already have the most sensitive fish species. The 

freshwater fish data can be used as a conservative estimate of fish toxicity; and the 

estuarine/marine fish toxicity on a chronic basis will likely not be more sensitive than freshwater 

fish. Therefore, no additional resources to conduct a study with estuarine/marine fish is needed.

Mysid Chronic Toxicity 

The reported NOAEC from the mysid life-cycle toxicity study is uncertain because it does not 

account for effects to offspring. No information was measured or recorded for the second 

generation mysids, whereas the OCSPP (form. OPPTS) guidance recommends that the offspring 

be maintained. Additionally, the survival and growth parameters (length and weight) were not 

separated by sex, and so no sex-specific analyses could be conducted from the available 

information. The study cannot be used to fulfill guideline requirements. Effects to estuarine/marine 

invertebrate offspring may be underestimated using the reported NOAEC. As a result, the 

submitted study does not fulfill guideline requirements and there were key reproductive endpoints 

missing from the submitted study, and a new study is needed. 
32 

Avian Acute Oral Toxicity – Passerine Species 

The dietary and dose-based EECs for small birds consuming short grass (most conservative) are 

143 ppm and 163 mg/kg-bw, respectively. No mortality or sublethal effects were observed in 

either the acute oral or subacute dietary toxicity tests for bobwhite quail or the acute oral toxicity 

study for mallard ducks. However, mortality and sublethal effects were both observed in the 

subacute dietary toxicity study for mallard ducks. Although mortality was observed it was less 

than 50% in all treatment levels (three total); however, clinical signs of toxicity were observed in 

all treatment groups (for a majority of the birds) up to 7 days after dosing. Observations include a 

reduction in body weight and feed consumption, nutation, unkemptness, decreased growth, and the 

NOAEC < 2017 ppm). Although there is a low application rate, there is a potential for exposure to 

passerine birds that cannot be dismissed, especially in light of the observed sublethal effects in the 

mallard duck dietary study. Based on this review, toxicity testing using passerine species is 

needed. 

Honeybee Toxicity 

Although fenpyroximate is categorized as practically non-toxic to adult honeybees on contact and 

oral exposure basis, and by extension, to other beneficial terrestrial invertebrates on an acute 

exposure basis, there is considerable uncertainty regarding the potential effects of the compound 

on honeybee larval development and survival as well as potential for chronic effects due to the 

mode of action. Fenpyroximate causes inhibition of molting of all immature stages, inhibits 

oviposition, and decreases feeding action. Therefore, additional data on pollinators is needed to 

fully characterize the risk associated with fenpyroximate use to all developmental stages of 

honeybees, as sensitivity may vary according to life-stage and length of exposure (adult vs. larval 

and acute vs. chronic, respectively). Additional information is needed, but uncertainty associated 

with risks to bees need to be evaluated with more data to different life stages. Open literature data 

is needed to help better characterize some uncertainties regarding potential effects to bees and 

other non-target terrestrial invertebrates. In addition, higher tier effects toxicity tests (i.e., semifield and/or field studies – Tier II and Tier III, respectively) may be needed, based on the results of 

the larval and chronic adult toxicity studies. Higher tier studies are recommended if the ratio of the 

EEC and larval or adult bee acute LD50>0.4 or the ratio of the EEC and the chronic NOAEC>1. 

Incident data and/or compelling open literature studies can also be used to support the need for 

higher tier studies. Should the screening level risk assessment identify that there are risk concerns 

to bees, mitigation measures may need to be considered or the registrant may need to conduct Tier 

II or Tier III effects studies (e.g. OECD Guideline 75 and/or 850.3040 guideline studies) that 

reduce uncertainty by characterizing fenpyroximates’s effects at the whole-colony level1

. 

 

 

1 http://www2.epa.gov/pollinator-protection/pollinator-risk-assessment-guidance. 
33 

Guideline Number: Non-Guideline 

Study Title: Larval Honey Bee Acute and Chronic Oral Toxicity

Rationale for Requiring the Data 

These studies are needed for the assessment to evaluate risks to honey bees if the registered uses will 

result in bee exposure. Fenpyroximate uses include aerial and ground applications to agricultural crops 

including citrus, cotton, vegetables including cucumbers, melons, fruits including pome, stone, and tree 

nuts as well as ornamentals and greenhouse uses where spray drift may land on blooming non-target 

plants and result in residues in pollen and nectar (which could then be transported to the hive). 

Additionally, fenpyroximate is relatively non-volatile, lipophilic, and slightly to hardly mobile in soil. 

Fenpyroximate causes inhibition of molting of all immature stages, inhibits oviposition, and decreases 

feeding action. Therefore, additional data on pollinators is needed to fully characterize the risk associated 

with fenpyroximate use to all developmental stages of honeybees, as sensitivity may vary according to 

life-stage and length of exposure. Residues can in turn be brought back to bee colonies where in-hive bees 

including young adult and developing brood (i.e., eggs, larvae and pupae) may be exposed. Therefore, 

exposure at all bee life stages would be expected. 

The Agency finalized its framework to assess risk to pollinators (USEPA, 2014). EPA now requires these 

studies for all use sites where potential exposure to pollinators may occur. Registrants may request a 

waiver of the studies if use practices significantly restrict exposure of the pesticide to bees. 

Although EPA has not developed a guideline for this study, the 21-day larval toxicity study currently 

under development by OECD provides both acute and chronic oral toxicity data on developing bee brood 

and (when this guidance is finalized) may be used to satisfy the requirement for both acute and chronic 

oral toxicity to honey bee larvae. Registrants are at liberty though to submit a separate acute (single dose) 

larval toxicity study following OECD TG 237 as well as the 21-day repeat dose chronic toxicity study. 

For the chronic toxicity study though, since no guideline is available, a protocol is required to be 

submitted prior to study initiation. 

Practical Utility of the Data 

How will the data be used and how could the data impact the Agency’s future decision-making? 

The 21-day larval toxicity study under development by OECD provides both acute and chronic toxicity 

data on developing bee brood and will yield a median lethal dose (LD50) for assessing acute toxicity 

during the early part of the study as well as a 21-day no-observed adverse effect level (NOAEL) and 

lowest-observed adverse effect level (LOAEL) for assessing chronic effects. Effects on survival and 

development (adult bee emergence) from repeat exposures to the active ingredient will be used in 

estimating chronic risk to individual brood. Risk estimates based on these data will be considered along 

with other lines of evidence to determine whether higher-tier studies are needed at the whole colony level. 

These data are needed for the registration review risk assessment and for future endangered species 

assessments. The data would allow the Agency better characterize the potential for risk to insects 

(including beneficial pollinators) from the use of fenpyroximate. This data may help the Agency 

determine whether any mitigations are needed. If the registration review and any future endangered 

species risk assessments are performed without these data, the Agency would have to assume that 

fenpyroximate "may affect" insects, including bees and beneficial pollinators, directly (and endangered 

species from other taxa indirectly), and uses of fenpyroximate might need to be restricted in areas where 

pollinators could be exposed. 

 
34 

Guideline Number: Non-Guideline 

Study Title: Adult Honey Bee Chronic Oral Toxicity

Rationale for Requiring the Data 

These studies are needed for the assessment to evaluate risks to honey bees if the registered uses will 

result in bee exposure. Fenpyroximate uses include aerial and ground applications to agricultural crops 

including citrus, cotton, vegetables including cucumbers, melons, fruits including pome, stone, and tree 

nuts as well as ornamentals and greenhouse uses where spray drift may land on blooming non-target 

plants and result in residues in pollen and nectar (which could then be transported to the hive). 

Additionally, fenpyroximate is relatively non-volatile, lipophilic, and slightly to hardly mobile in soil. 

Fenpyroximate causes inhibition of molting of all immature stages, inhibits oviposition, and decreases 

feeding action. Therefore, additional data on pollinators is needed to fully characterize the risk associated 

with fenpyroximate use to all developmental stages of honeybees, as sensitivity may vary according to 

life-stage and length of exposure. Therefore, exposure at all bee life stages would be expected and may 

extend for chronic exposures. 

The Agency finalized its framework to assess risk to pollinators (USEPA, 2014). EPA now requires this 

study for all use sites where potential exposure to pollinators may occur. Registrants may request a 

waiver of the study if use practices significantly restrict exposure of the pesticide to bees. 

Although EPA has not developed a guideline for this study and OECD has yet to finalize test guidance for 

chronic studies, efforts are currently underway to develop standardized guidelines for assessing effects 

from chronic (10-day) exposures to adult bees in the laboratory. A protocol is required to be submitted 

prior to study initiation. 

Practical Utility of the Data 

How will the data be used and how could the data impact the Agency’s future decision-making? 

The 10-day toxicity study with young adult bees provides no-observed adverse effect level (NOAEL) and 

lowest-observed adverse effect level (LOAEL) for assessing chronic effects. Data obtained from this 

study will be used in estimating chronic risk to individual adult bees. Risk estimates based on these data 

will be considered along with other lines of evidence to determine whether higher-tier studies are needed 

at the whole colony level. 

These data are needed for the registration review risk assessment and for future endangered species 

assessments. The data would allow the Agency better characterize the potential for risk to insects 

(including beneficial pollinators) from the use of fenpyroximate. This data may help the Agency 

determine whether any mitigations are needed. If the registration review and any future endangered 

species risk assessments are performed without these data, the Agency would have to assume that 

fenpyroximate "may affect" insects, including bees and beneficial pollinators, directly (and endangered 

species from other taxa indirectly), and uses of fenpyroximate might need to be restricted in areas where 

pollinators could be exposed. 

 
35 

12. References 

United States Environmental Protection Agency (USEPA). 2003. Stokes, J., G. Reddy, and J. 

Breithaupt. Fenpyroximate: Conclusion and Briefing Memorandum for 07/09/03 Meeting 

of the Health Effects Division (HED) Metabolism Assessment Review Committee 

(MARC). DP barcode 292639. U.S. Environmental Protection Agency, Office of 

Prevention, Pesticides, and Toxic Substances, Health Effects Division. Internal 

memorandum. Aug. 12, 2003. 

USEPA. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide 

Programs. U.S. Environmental Protection Agency, Office of Pesticide Programs, 

Environmental Fate and Effects Division. Available at 

http://www.epa.gov/espp/consultation/ecorisk-overview.pdf

USEPA. Kaul, M. 2007. Maximum Number of Crop Cycles per Year in California for Methomyl 

Use Sites. U.S.Environmental Protection Agency, Office of Prevention, Pesticides, and 

Toxic Substances, Biological and Economic Analysis Division. Memorandum to M. 

Panger, Environmental Fate and Effects Division. Feb. 28, 2007. 

United States Geological Survey (USGS). 2014. National Water-Quality Assessment (NAWQA) 

Program, Pesticide National Synthesis Project, Pesticide Use Maps – Diclofop. 

http://water.usgs.gov/nawqa/pnsp/usage/maps/show_map.php?year=2011&map=FENPY

ROXIMATE&hilo=L&disp=Fenpyroximate (accessed May 23, 2014) 

USEPA, PMRA and CDPR, 2014. Guidance for Assessing Pesticide Risks to Bees. Office of 

 Pesticide Programs, USEPA, Washington D.C. Health Canada Pest Management 

 Regulatory Agency, Ottawa, ON, Canada. California Department of Pesticide Regulation, 

 Sacramento, CA. June 23, 2014. Available at 

http://www2.epa.gov/pollinator-protection/pollinator-risk-assessment-guidance. 

a. Submitted Product Chemistry and Environmental Fate Studies

MRID Citation Reference 

44781003 Todhunter, J.; Hill, J. (1999) Fenpyroximate--Technical Active Ingredient (TGAI) and Fenpyroximate 

5% SC (End Use Product): Product Chemistry, Series 63: Lab Project Number: NNI-FENPY-99-003. 

Unpublished study prepared by SRS International Corporation. 19 p. 

44781016 Swanson, M. (1993) Direct Photolysis of Pyrazole-14C-Fenpyroximate in a Buffered Aqueous 

Solution Under Artificial Sunlight: Final Report: Lab Project Number: SC910077: SC910089: E4015. Unpublished study prepared by Battelle Memorial Institute. 126 p. 

44847909 Saxena, A.; McCann, D. (1992) Hydrolysis of Pyrazole-14C-Fenpyroximate in Buffered Aqueous 

Solutions: Final Report: Lab Project Number: SC900192. Unpublished study prepared by Battelle 

Memorial Institute. 97 p. 

45187901 Funayama, S.; Atsuko, H.; Izawa, Y. (1990) Degradation of [Pyrazole-14C] and [Benzyl-14C] 

Fenpyroximate in Soils Under Laboratory Conditions: Lab Project Number: E-4005. Unpublished 

study prepared by Nihon Nohyaku Co., Ltd. 52 p. 

45649705 Concha, M. (2001) Photodegradation of 14C-Fenpyroximate in/on Soil by Artificial Light: Lab Project 

Number: E-4030: 870W-1: 870W. Unpublished study prepared by PTRL West, Inc. 188 p. 
36 

MRID Citation Reference 

45649706 Maks, M. (2002) Degradation of [Pyrazole-14C] and [Benzyl-14C] Fenpyroximate in Soils Under 

Laboratory Conditions: Lab Project Number: E-4005. Unpublished study prepared by Nichino 

America, Inc. 8 p. 

45649707 McKemie, T.; Shepler, K. (2001) Anaerobic Aquatic Metabolism of [14C] Fenpyroximate: Lab Project 

Number: 889W-1: 889W: E-4031. Unpublished study prepared by PTRL West, Inc. 232 p. 

45649708 Concha, M. (2002) Soil Adsorption/Desorption of [14C] M-3 by the Batch Equilibrium Method: Lab 

Project Number: 1045W. Unpublished study prepared by PTRL West, Inc. 132 p. 

45649709 Concha, M. (2002) Soil Adsorption/Desorption of [14C ] Fenpyroximate by the Batch Equilibrium 

Method: Lab Project Number: 987W: E-4033. Unpublished study prepared by PTRL West, Inc. 151 p. 

45649710 Burstell, H.; Sochor, H. (1994) Fenpyroximate Water Miscible Suspension 50g/l: Investigation of the 

Degradation Behaviour in Soil Under Field Conditions: Lab Project Number: E-4028: ER91DEU824: 

A53773. Unpublished study prepared by Hoechst Schering AgrEvo GmbH. 55 p. 

45649711 Specht, W. (1993) Determination of the Residues of Fenpyroximate (HOE 094552), M-1 (HOE 

112573) and M-3 (HOE 112721) in Soil: Lab Project Number: HOE-9107: 93615/91: A53773. 

Unpublished study prepared by Chemische Laboratorien GMBH. 146 p. 

45649712 Baker, F.; Mickelson, K.; Hiler, R. (2001) Field Soil Dissipation of Fenpyroximate in Bare Ground in 

North Carolina, Arkansas, and California: Lab Project Number: 803W-1: 803W: E-4032. Unpublished 

study prepared by Research for Hire. 253 p. 

45734203 Hiler, R. (2002) Quantification of Metabolites M-3, M-8, and M-11 in Soil from Field Soil 

Dissipation of Fenpyroximate in Bare Ground in North Carolina, Arkansas and California: Lab Project 

Number: E-4038: 1026W: 1026W-1. Unpublished study prepared by Research for Hire. 855 p. 

46158501 Shepler, K. (2003) Aerobic Soil Metabolism of [14C ] Fenpyroximate. Project Number: 1038W. 

Unpublished study prepared by PTRL West, Inc. 160 p. 

47521406 Volkl, D. (2001) [14C] Fenpyroximate (NNI-850) [Pyrazole-labelled] Degradation and Metabolism in 

Aquatic Systems. Project Number: E/4027/SUPP/1, 7L365. Unpublished study prepared by RCC Ltd. 

134 p. 

48381102 Thomas, S.; Kendall, T.; Krueger, H. (2010) Fenpyroximate: A Bioconcentration Test with the 

Bluegill (Lepomis macrochirus): Final Report. Project Number: 397A/140. Unpublished study 

prepared by Wildlife International, Ltd. 93 p. 

b. Submitted Ecological Toxicity Studies

MRID Citation Reference 

45649714 Tolle, D. (1991) Avian Single-Dose LD (50) Test of Fenpyroximate in Mallard Ducks: Final Report: 

Lab Project Number: SC910033. Unpublished study prepared by Battelle. 46 p. 

45649715 Tolle, D. (1991) Avian Single-Dose LD (50) Test of Fenpyroximate in Bobwhite Quail: Final Report: 

Lab Project Number: SC910018: W-4031. Unpublished study prepared by Battelle. 44 p. 

44847908 Tolle, D. (1991) 8-Day Avian Dietary LC50 Test of Fenpyroximate in Bobwhite Quail: Final Report: 

Lab Project Number: SC910016: W-4015. Unpublished study prepared by Battelle. 76 p. 

45649716 Tolle, D. (1991) 8-Day Avian Dietary LD (50) Test of Fenpyroximate in Mallard Ducks: Final 

Report: Lab Project Number: SC910017: W-4016. Unpublished study prepared by Battelle. 77 p. 

45649717 Stadens-Peek, W.; Frieling, W. (1997) 6-Weeks Dietary Study in Mallard Duck with Fenpyroximate 

(Pilot Dietary Study for Reproduction Study): Lab Project Number: 191778: 67455: W-4046. 

Unpublished study prepared by NOTOX B.V. 39 p. 
37 

MRID Citation Reference 

45649718 van Dreumel, I.; Frieling, W. (1997) Reproduction Study in Mallard Duck with Fenpyroximate (By 

Dietary Admixture): Lab Project Number: 191047: 67455: W-4047. Unpublished study prepared by 

NOTOX B.V. 154 p. 

45649719 Frieling, W. (2001) Reproduction Study in Bobwhite Quail with Fenpyroximate Technical (By 

Dietary Admixture): Lab Project Number: 265027: 64577: W-6062. Unpublished study prepared by 

NOTOX B.V. 210 p. {OPPTS 850.2300} 

45649720 Todhunter, J. (2002) Analysis and Evaluation of Data from a Fenpyroximate Reproduction Study in 

Bobwhite Quail Conducted at NOTOX B.V: Lab Project Number: W-4062: 265027. Unpublished 

study prepared by SRS International Corp. 21 p. 

47521403 Temple, D.; Martin, K.; Beavers, J.; et al. (2008) Fenpyroximate: A Reproduction Study with the 

Mallard: Final Report. Project Number: 397/106. Unpublished study prepared by Wildlife 

International, Ltd. 156 p. 

47521404 Temple, D.; Martin, K.; Beavers, J.; et al. (2008) Fenpyroximate: A Reproduction Study with the 

Northern Bobwhite: Final Report. Project Number: 397/105. Unpublished study prepared by Wildlife 

International Ltd. 159 p. 

44781014 Knacker, T.; Brodesser, H.; Schallnab, H. et al. (1992) A Study of the Acute Toxicity to Fish 

(Oncorhynchus mykiss) of Fenpyroximate Under Flow-Through Conditions: Final Report (Revised): 

Lab Project Number: BF-EA-101-91-01-FIA-1. Unpublished study prepared by Battelle Europe. 62 p. 

45477201 Maks, M. (2001) Addendum 1 to A Study of the Acute Toxicity to Fish (Oncorhynchus mykiss) of 

Fenpyroximate Under Flow-Through Conditions: Lab Project Number: BE-EA-107-91-01-FIA-1. 

Unpublished study prepared by Battelle Europe, and Nihon Nohyaku Company, Ltd. 15 p. 

45649721 Dionne, E. (2001) Fenpyroximate Technical--Acute Toxicity to Bluegill Sunfish (Lepomis 

macrochirus) Under Flow-Through Conditions: Lab Project Number: 13657.6134: W-4055. 

Unpublished study prepared by Springborn Laboratories, Inc. 55 p. {OPPTS 850.1075} 

45649801 Dionne, E. (2001) Fenpyroximate 5% EC--Acute Toxicity to Bluegill Sunfish (Lepomis macrochirus) 

Under Flow-Through Conditions: Lab Project Number: 13657.6141: W-4060: 

093098/FIFRA/OPPTS/1. Unpublished study prepared by Springborn Laboratories, Inc. 55 p. 

{OPPTS 850.1075} 

45649802 Knacker, T.; Brodesser, J.; Schallnass, H.; et al. (1992) A Study of the Acute Toxicity to Fish 

(Cyprinus carpio) of Fenpyroximate Under Flow-Through Conditions: Final Report: Lab Project 

Number: BE-EA-107-91-01-F5A-: W-4004. Unpublished study prepared by Battelle Europe. 66 p. 

45649803 Dionne, E. (2001) Fenpyroximate 5% EC--Acute Toxicity to Rainbow Trout (Oncorhynchus mykiss) 

Under Flow-Through Conditions: Lab Project Number: 13657.6140: W-4059. Unpublished study 

prepared by Springborn Laboratories, Inc. 55 p. {OPPTS 850.1075} 

46188801 Habig, C. (2004) Addendum 2 to A Study of the Acute Toxicity to Fish (Oncorhynchus mykiss) of 

Fenpyroximate Under Flow-Through Conditions (MRID # 44781014). Project Number: 

BE/EA/107/91/01/FIA/1. Unpublished study prepared by Battelle Europe and Nihon Nohyaku Co. 

Ltd. 6 p. 

47021402 Maks, M. (2007) Supplement 1 to Fenpyroximate 5 Percent EC-Acute Toxicity to Rainbow Trout 

(Oncorhynchus mykiss) Under Flow-Through Conditions. Project Number: 13657/6140, W/4059. 

Unpublished study prepared by Springborn Smithers Laboratories. 7 p. 

46799201 Palmer, S.; Kendall, T.; Krueger, H. (2006) Fenpyroximate TGAI: A 96-Hour Static-Renewal Acute 

Toxicity Test With the Rainbow Trout: Final Report. Project Number: 397A/105. Unpublished study 

prepared by Wildlife International, Ltd. 40 p. 

46974402 Pawlowski, S.; Wydra, V. (2005) Acute Toxicity of M-3, A Fenpyroximate Matabolie, to Rainbow 

Trout (Oncorhynchus mykiss) in a 96-Hour Static Test: Final Report. Project Number: 23771230. 

Unpublished study prepared by Institut fuer Biologische Analytik und Consulting IBACON. 58 p. 
38 

MRID Citation Reference 

47021402 Maks, M. (2007) Supplement 1 to Fenpyroximate 5 Percent EC-Acute Toxicity to Rainbow Trout 

(Oncorhynchus mykiss) Under Flow-Through Conditions. Project Number: 13657/6140, W/4059. 

Unpublished study prepared by Springborn Smithers Laboratories. 7 p. 

47098102 Palmer, S.; Kendall, T.; Krueger, H. (2007) Fenpyroximate 5% EC: A 96-Hour Flow - Through Acute 

Toxicity Test with the Rainbow Trout (Oncorhynchus mykiss): Final Report. Project Number: 

397A/109. Unpublished study prepared by Wildlife International, Ltd. 43 p. 

44781015 Knacker, T.; Zietz, E.; Schallnab, H. et al. (1992) A Study of the Acute Toxicity to the Freshwater 

Aquatic Invertebrate (Daphnia magna) of Fenpyroximate: Final Report (Revised): Lab Project 

Number: BE-EA-107-90-01-DAK-1. Unpublished study prepared by Battelle Europe. 55 p. 

46800801 Palmer, S.; Kendall, T.; Krueger, H. (2006) Fenpyroximate 5%EC: A 48-Hour Static-Renewal Acute 

Toxicity Test with the Cladoceran (Daphnia magna): Final Report. Project Number: 397A/103A. 

Unpublished study prepared by Wildlife International, Ltd. 43 p. 

46974401 Motoba, K. (2005) Acute Immobilization Test of M-3, A Fenpyroximate Metabolite on Daphnia 

Magna: Final Report. Project Number: GC/12, 05/0035. Unpublished study prepared by Nihon 

Nohyaku Co., Ltd. 41 p. 

45649805 

Dionne, E. (2001) Fenpyroximate Technical--Acute Toxicity to Sheepshead Minnow (Cyprinodon 

variegatus) Under Flow-Through Conditions: Lab Project Number: 13657.6135: W-4057: 

020499/FIFRA/OPPTS/F. Unpublished study prepared by Springborn Laboratories, Inc. 52 p. 

{OPPTS 850.1075} 

46188802 

Dionne, E. (2001) Fenpyroximate Technical - Acute Toxicity to Sheepshead Minnow (Cyprinodon 

variegatus) Under Flow-Through Conditions. Project Number: 13657/6135, W/4057, 

020499/FIFRA/OPPTS/FT/SHM. Unpublished study prepared by Springborn Laboratories Inc. 52 p. 

47098101 

Palmer, S.; Kendall, T.; Krueger, H. (2007) Fenpyroximate TGAI: A 96-Hour Flow - Through Acute 

Toxicity Test with the Sheepshead Minnow (Cyprinodon variegatus): (Fujimite 5EC 

Miticide/Insecticide): Final Report. Project Number: 397A/110. Unpublished study prepared by 

Wildlife International, Ltd. 41 p. 

45649804 

Dionne, E. (2001) Fenpyroximate Technical--Acute Toxicity to Mysids (Americamysis bahia) Under 

Flow-Through Conditions: Lab Project Number: 13657.6137: W-4058. Unpublished study prepared 

by Springborn Laboratories, Inc. 56 p. {OPPTS 850.1035} 

45649806 

Dionne, E. (2001) Fenpyroximate Technical--Acute Toxicity to Eastern Oyster (Crassostrea virginica) 

Under Flow-Through Conditions: Lab Project Number: 13657.6136: W-4056. Unpublished study 

prepared by Springborn Laboratories, Inc. 58 p. {OPPTS 850.1025} 

 47021401 Palmer, S.; Kendall, T.; Krueger, H. (2006) Fenpyroximate TGAI: A 96-Hour Shell Deposition Test 

with the Eastern Oyster (Crassostrea virginica): Final Report. Project Number: 397A/111. 

Unpublished study prepared by Wildlife International, Ltd. 40 p. 

45649808 Sousa, J. (2001) Fenpyroximate Technical--The Toxicity to Fathead Minnow (Pimephales promelas) 

During an Early Life-Stage Exposure: Lab Project Number: 13657.6142: W-4061. Unpublished study 

prepared by Springborn Laboratories, Inc. 71 p. 

46188803 Sousa, J. (2004) Supplement 1 to Fenpyroximate Technical-The Toxicity to Fathead Minnow 

(Pimephales promelas) During an Early Life-Stage Exposure (MRID No. 45649808). Project Number: 

13657/6142, W/4061, 346230. Unpublished study prepared by Springborn Laboratories Inc. and 

Nihon Nohyaku Co. Ltd. 25 p. 

45649807 Knacker, T.; Brodresser, J.; Reifenberg, P.; et al. (1992) A Study of the Chronic Toxicity to Daphnia 

of Fenpyroximate: Final Report: Lab Project Number: BE-EA-107-90-01-DCH-: W-4034. 

Unpublished study prepared by Battella Europe. 97 p. 

46188804 Habig, C. (2004) Supplement 1 to A Study of the Chronic Toxicity to Daphnia of Fenpyroximate 

(MRID No. 45649807). Project Number: BE/EA/107/90/01/DCH/1: W/4034. Unpublished study 

prepared by Battelle Europe. 9 p. 
39 

MRID Citation Reference 

47098103 Palmer, S.; Kendall, T.; Krueger, H. (2007) Fenpyroximate TGAI: A Flow - Through Life - Cycle 

Toxicity Test with the Cladoceran (Daphnia magna): Final Report. Project Number: 397A/106A. 

Unpublished study prepared by Wildlife International, Ltd. 61 p. 

47521405 Palmer, S.; Kendall, T.; Krueger, H. (2007) Fenpyroximate TGAI: A Flow-Through Life-Cycle 

Toxicity Test with the Saltwater Mysid (Americamysis bahia): Final Report. Project Number: 

397A/108. Unpublished study prepared by Wildlife International Ltd. 75 p 

48381101 Thomas, S.; Krueger, H.; Kendall, T.; et al. (2010) Fenpyroximate: A 10-Day Survival and Growth 

Toxicity Test with the Midge Chironomus tentans Using Spiked Sediment: Final Report. Project 

Number: 397A/141. Unpublished study prepared by Wildlife International, Ltd. 73 p. 

46847202 Heusel, R. (1997) Fenpyroximate (Carbon 14)-Labelled Chronic Toxicity to the Sediment Dwelling 

Chironomid Larvae (Chironomus riparius). Project Number: CE96/077, W/4044. Unpublished study 

prepared by Hoechst Schering Agrevo Gmbh. 60 p. 

45649809 Teixeira, D. (2001) Fenpyroximate 5% EC--Determination of Effects on Seedling Emergence of Ten 

Plant Species: Lab Project Number: 13657.6157. Unpublished study prepared by Springborn 

Laboratories, Inc. 188 p. {OPPTS 850.4100, 850.4225} 

45649810 

Teixeira, D. (2001) Fenpyroximate 5% EC--Determination of Effects on Vegetative Vigor of Ten 

Plant Species: Lab Project Number: 13657.6158: 022301/OPPTS/VV. Unpublished study prepared by 

Springborn Laboratories, Inc. 143 p. {OPPTS 850.4150, 850.4250} 

45649811 Hoberg, J. (2001) Fenpyroximate 5% EC--Toxicity to Duckweed, Lemna gibba: Lab Project Number: 

13657.6154: N-4060. Unpublished study prepared by Springborn Laboratories, Inc. 54 p. {OPPTS 

850.4400} 

45649812 Hoberg, J. (2001) Fenpyroximate 5.0% EC--Acute Toxicity to Freshwater Diatom (Navicula 

pellicullosa): Lab Project Number: 13657.6151: N-4056. Unpublished study prepared by Springborn 

Laboratories, Inc. 51 p. {OPPTS 850.5400} 

45649813 Hoberg, J. (2001) Fenpyroximate 5.0% EC--Acute Toxicity to Freshwater Blue-Green Alga, 

Anabaena flos-aquae: Lab Project Number: 13657.6153: N-4057. Unpublished study prepared by 

Springborn Laboratories, Inc. 50 p. {OPPTS 850.5400} 

45649814 Hoberg, J. (2001) Fenpyroximate 5.0% EC--Acute Toxicity to Freshwater Green Alga, 

Pseudokirchneriella subcapitata: Lab Project Number: 13657.6150: N-4058. Unpublished study 

prepared by Springborn Laboratories, Inc. 52 p. {OPPTS 850.5400} 

45649815 Hoberg, J. (2001) Fenpyroximate 5.0% EC--Acute Toxicity to Marine Diatom, Skeletonema 

costatum: Lab Project Number: 13657.6152: N-4059. Unpublished study prepared by Springborn 

Laboratories, Inc. 51 p. {OPPTS 850.5400} 

45649816 Heusel, R. (1992) Fenpyroximate-Substance, Technical: Effect to Scendesmus suspicatus (Green 

Alga) in Growth Inhibition Test: Lab Project Number: CE90/119: N-4016: A48254. Unpublished 

study prepared by Hoechst AG. 31 p. 

45649817 Fischer, R. (1990) HOE 094552-Water Miscible Suspension Concentrate; 5%: Effect to Scendesmus 

suspicatus (Green Alga) in Growth Inhibition Test: Lab Project Number: CE90/085: N-4017: A44948. 

Unpublished study prepared by Hoechst AG. 24 p. 

47021403 Maks, M. (2007) Supplement 1 to Fenpyroximate 5 Percent EC-Acute Toxicity to the Marine Diatom 

(Skeletonema costatum). Project Number: 13657/6152, N/4059. Unpublished study prepared by 

Springborn Smithers Laboratories. 9 p. 

47021404 Maks, M. (2007) Supplement 1 to Fenpyroximate 5 Percent EC-Acute Toxicity to the Freshwater 

Green Alga, Pseudokirchneriella Subcapitata. Project Number: 13657/6150, N/4058. Unpublished 

study prepared by Springborn Smithers Laboratories. 7 p. 
40 

MRID Citation Reference 

45649818 Krebs, B. (2000) Contact Toxicity (LD50) to Honey Bees (Apis mellifera L.) Fenpyroximate Water 

Miscible Suspension Concentrate: Lab Project Number: C008608: KS-023-06-2000: N-4040. 

Unpublished study prepared by Aventis CropScience GmbH. 16 p. 

45649819 Waltersdorfer, A. (2000) Oral Toxicity (LD50) to Honey Bees (Apis mellifera L.) Fenpyroximate 

Substance Technical: Lab Project Number: CW99/137: N-4039. Unpublished study prepared by 

Hoechst Schering AgrEvo GmbH. 16 p. 

47737801 Walsh, D. (2009) Pollinator Pesticide Safety Trials 2007: Flonicamid. Project Number: 

IB/2009/PH/002/01. Unpublished study prepared by Washington State University. 19 p. 

45649821 Kimura, M. (1991) Acute Toxicity Study of Fenpyroximate in Phytoseild Mites: Lab Project Number: 

N-4003. Unpublished study prepared by Nihon Nohyaku Company. 9 p. 

45649822 Kimura, M. (1991) Acute Toxicity Study of Fenpyroximate in Green Lacewing: Lab Project Number: 

N-4004. Unpublished study prepared by Nihon Nohyaku Company. 11 p. 

45649823 Kimura, M. (1991) Acute Toxicity Study of Fenpyroximate in Ladybug: Lab Project Number: N4005. Unpublished study prepared by Nihon Nohyaku Company. 11 p. 

45649824 Kimura, M. (1992) Acute Toxicity Study of Fenpyroximate in Predacious Thrips, Scolothrips, Sp: Lab 

Project Number: N-4022. Unpublished study prepared by Nihon Nohyaku Company. 8 p. 

45649825 Chisholm, K. (1992) Fenpyroximate and Fenpyroximate 5% SC: Acute Toxicity Studies to Beneficial 

Arthropods: Lab Project Number: FEN-EC-03: N-4008: CW00/019. Unpublished study prepared by 

Nihon Nohyaku Company. 230 p. 

48381102 Thomas, S.; Kendall, T.; Krueger, H. (2010) Fenpyroximate: A Bioconcentration Test with the 

Bluegill (Lepomis macrochirus): Final Report. Project Number: 397A/140. Unpublished study 

prepared by Wildlife International, Ltd. 93 p. 

45649820 

48735301 

48735302 

Fischer, R. (1991) HOE 094552--Substance, Technical: Effect to Eisenia fetida (Earthworm) in a 14 

Day Artificial Soil Test: Lab Project Number: CE90/118: N-4014: A 45245. Unpublished study 

prepared by Hoechst AG. 32 p. 

York, D. (2010) [14C] Fenpyroximate – Full Life-Cycle Toxicity Test with Fathead Minnow 

(Pimephales promelas) Following FIFRA Guideline 72-5 and OPPTS Draft Guideline 850.1500. 

Laboratory Project ID: Springborn Smithers Study No. 13657.6162. Unpublished study prepared by 

Springborn Smithers Laboratories. 151 p. 

Gray, J. (2011). Evaluation of the Effects of Fenpyroximate on the Parasitoid Wasp Aphidius 

rhopalosiphi in an Extended Laboratory Aged Residue Study on Broad Bean: Amended Final Report. 

Huntingdon Life Sciences Study Number: LMS0016. Unpublished study prepared by Huntingdon Life 

Sciences Ltd. 61 p. 
41 

APPENDIX A. STIR & SIP Model Outputs 

STIR Model Output 

Input 

Application and Chemical Information 

Enter Chemical Name Fenpyroximate 

Enter Chemical Use 

Ag, Greenhouse, 

etc. 

Is the Application a Spray? (enter y or n) y 

If Spray What Type (enter ground or air) ground 

Enter Chemical Molecular Weight (g/mole) 421.5 

Enter Chemical Vapor Pressure (mmHg) 5.60E-08 

Enter Application Rate (lb a.i./acre) 0.34 

 

Toxicity Properties 

Bird 

Enter Lowest Bird Oral LD50 (mg/kg bw) 2000 

Enter Mineau Scaling Factor 1.15 

Enter Tested Bird Weight (kg) 0.158 

Mammal 

Enter Lowest Rat Oral LD50 (mg/kg bw) 245 

Enter Lowest Rat Inhalation LC50 (mg/L) 0.24 

Duration of Rat Inhalation Study (hrs) 4 

Enter Rat Weight (kg) 0.298 

 

Output 

Results Avian (0.020 kg ) 

Maximum Vapor Concentration in Air at Saturation 

(mg/m3) 1.27E-03 

Maximum 1-hour Vapor Inhalation Dose (mg/kg) 1.60E-04 

Adjusted Inhalation LD50 1.31E+01 

Ratio of Vapor Dose to Adjusted Inhalation LD50 1.22E-05 Exposure not Likely Significant 

Maximum Post-treatment Spray Inhalation Dose 

(mg/kg) 3.59E-02 

Ratio of Droplet Inhalation Dose to Adjusted 

Inhalation LD50 2.75E-03 Exposure not Likely Significant 

 

Results Mammalian (0.015 kg ) 

Maximum Vapor Concentration in Air at Saturation 

(mg/m3) 1.27E-03 

Maximum 1-hour Vapor Inhalation Dose (mg/kg) 2.01E-04 

Adjusted Inhalation LD50 1.61E+01 

Ratio of Vapor Dose to Adjusted Inhalation LD50 1.25E-05 Exposure not Likely Significant 

Maximum Post-treatment Spray Inhalation Dose 

(mg/kg) 4.52E-02 

Ratio of Droplet Inhalation Dose to Adjusted 

Inhalation LD50 2.80E-03 Exposure not Likely Significant 

 
42 

SIP Model Output 

Table 1. Inputs 

Parameter Value 

Chemical name Fenpyroximate 

Solubility (in water at 25oC; mg/L) 0.034 

 

Mammalian LD50 (mg/kg-bw) 245 

Mammalian test species laboratory rat 

Body weight (g) of "other" mammalian species 

 

Mammalian NOAEL (mg/kg-bw) 1.99 

Mammalian test species laboratory rat 

Body weight (g) of "other" mammalian species 

 

Avian LD50 (mg/kg-bw) 2000 

Avian test species northern bobwhite quail 

Body weight (g) of "other" avian species 

Mineau scaling factor 

 

Mallard NOAEC (mg/kg-diet) 35 

Bobwhite quail NOAEC (mg/kg-diet) 255 

NOAEC (mg/kg-diet) for other bird species 

Body weight (g) of other avian species 

NOAEC (mg/kg-diet) for 2nd other bird species 

Body weight (g) of 2nd other avian species 

 

Table 2. Mammalian Results 

Parameter Acute Chronic 

Upper bound exposure (mg/kg-bw) 0.0058 0.0058 

Adjusted toxicity value (mg/kg-bw) 188.4443 1.5306 

Ratio of exposure to toxicity 0.0000 0.0038 

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) 0.0275 0.0275 

Adjusted toxicity value (mg/kg-bw) 17800.0000 1.7364 

Ratio of exposure to acute toxicity 0.0000 0.0159 

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.