1 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460

November 30, 2011 

PC Code: 090112 

MEMORANDUM DP Barcode: 373577

SUBJECT: Penthiopyrad (MTF-753): Section 3 New Chemical Environmental Fate and 

Ecological Risk Assessment 

FROM: Christina Wendel, Biologist 

 Greg Orrick, Environmental Scientist 

 Environmental Risk Branch II 

Environmental Fate and Effects Division (7507P) 

THROUGH: Brian Anderson, Branch Chief 

 Jean Holmes, Risk Assessment Process Leader 

 Kristina Garber, Senior Biologist 

 James Lin, Environmental Engineer 

 Environmental Risk Branch II 

Environmental Fate and Effects Division (7507P) 

TO: Tawanda Maignan, Risk Manager Reviewer 

Tony Kish, Risk Manager 

 Fungicide Branch, RM Team 22 

 Registration Division (7505P) 

The Environmental Fate and Effects Division (EFED) has completed its ecological risk 

assessment for the new fungicide penthiopyrad, which includes proposed new uses on alfalfa, 

brassica vegetables, bulb vegetables, canola, cereals (excluding rice and wild rice), cotton, 

cucurbits, fruiting vegetables, leafy vegetables, low growing berries (including cranberries), 

peanuts, pome fruits, root and tuber vegetables and leaves, stone fruits, succulent and dry 

legumes, sunflowers, tree nuts (including pistachios and excluding pecans), turf (including sod 

farms and any landscaped areas) and landscape ornamentals. Four end use formulations of 

penthiopyrad are proposed for registration in the United States. These include Fontelis (20% 

active ingredient (a.i.)), a suspension concentrate (SC) for a range of agricultural uses; Vertisan 

(20% a.i.), an emulsifiable concentrate (EC) for a range of agricultural uses; Treoris (8.9% a.i.), a 

suspension concentrate (SC) containing 22.3% chlorothalonil and for a range of agricultural 

uses; and Velista (50% a.i.), water dispersible granules (WG) for use on turf and landscape 

ornamentals. 

The results of this assessment indicate that the proposed uses of penthiopyrad other than canola 
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have the potential for direct adverse effects on listed freshwater fish (a surrogate for aquaticphase amphibians). Also, acute effects on listed estuarine/marine fish and invertebrates (via 

spray drift from Fontelis formulation) cannot be precluded. The proposed use on cranberries 

results in potential direct adverse acute effects on listed and non-listed freshwater fish (a 

surrogate for aquatic-phase amphibians); acute effects on listed freshwater invertebrates, 

estuarine/marine fish and invertebrates; chronic effects to freshwater fish and estuarine/marine 

invertebrates1

; and acute effects on listed estuarine/marine fish and invertebrates (via spray drift 

from the Fontelis formulated product). All proposed uses of penthiopyrad result in potential 

direct adverse chronic effects on listed and non-listed mammals. Due to effects seen at the single 

application rate for both terrestrial monocot and dicot plant species in the seedling emergence 

and vegetative vigor toxicity tests and the absence of establishing an NOAEC or EC05, risk to 

terrestrial plants and animals with obligate relationships with plants are assumed to exceed LOCs 

for listed species. Based on the submitted toxicity data for the formulations of penthiopyrad, 

exposure to penthiopyrad may adversely affect sensitive arthropod species including honeybees. 

Toxic effects were observed in honeybees and beneficial insects at and below proposed 

application rates of penthiopyrad. Although at this time risk to these taxa cannot be quantified, it 

is possible that adverse effects to terrestrial invertebrates, including pollinators and beneficial 

insects, may occur based on exposure to the Fontelis, Vertisan, and/or Treoris formulated 

products of penthiopyrad in and around the use areas of the proposed uses of penthiopyrad. 

Therefore, levels of concern were exceeded for all taxonomic groups for either direct or indirect 

effects. 

In order to result in no LOC exceedances for all listed aquatic organisms, the application rate for 

the proposed use of highest exposure using the PE model (succulent legumes) would have to be 

reduced to one treatment per year at 0.29 lbs a.i./A. The application rate for the proposed use 

with the smallest LOC exceedance (sugarbeets) would have to be reduced to 2 treatments per 

year at 0.27 lbs a.i./A or the proposed application rate of 0.39 lbs a.i./A could be limited to one 

treatment per year in order to result in no LOC exceedances. If the proposed use on succulent 

legumes is reduced to one treatment per year at 0.39 lbs a.i./A, then the chronic LOC is not 

exceeded for any size class of mammals that consume aquatic prey. The application rate for the 

proposed use on cranberries would have to be reduced to one treatment per year at 0.055 lbs 

a.i./A in order to result in no LOC exceedances for listed aquatic organisms. 

Based on the environmental fate and transport characteristics of penthiopyrad, the following 

surface water label advisory is recommended. 

For surface water: 

“This product may impact surface water quality due to runoff of rain 

water. This is especially true for poorly draining soils and soils with 

shallow ground water. This product is classified as having high potential

for reaching surface water via runoff for several weeks after application. 

A level, well-maintained vegetative buffer strip between areas to which 

 

1

 Based on the refined cranberry model calculated EEC values, and derived acute and chronic RQs. The Tier I rice 

model calculated EEC value results in potential direct adverse acute and chronic effects to all aquatic organisms, as 

well as aquatic non-vascular plants. 
-Page 3 of 166- 

this product is applied and surface water features such as ponds, streams, 

and springs will reduce the potential loading of this chemical from runoff 

water and sediment. Runoff of this product will be reduced by avoiding 

applications when rainfall is forecasted to occur within 48 hours.” 

All of the available ecological effect and environmental fate studies that were submitted to fulfill 

data requirements under 40 CFR Pt. 158 for aquatic and terrestrial food and non-food uses are 

tabulated in Appendices H and I. Also tabulated are the study classifications and whether 

additional data are needed for the risk assessment. The following paragraphs describe the notable 

gaps in the data set for penthiopyrad. 

Data gaps and needs for penthiopyrad include: 

 a passerine subacute dietary study using the penthiopyrad TGAI 

 an oyster BCF study using the penthiopyrad TGAI; 

 an estuarine/marine invertebrate (mysid) chronic toxicity study using the penthiopyrad 

TGAI; 

 estuarine/marine aquatic invertebrates (mysid and oyster) acute toxicity studies using the 

Fontelis (DPX-LEM17 20SC) formulation; 

 an estuarine/marine fish acute toxicity study using the Fontelis formulation; 

 a Tier II seedling emergence study using the Fontelis formulation; and 

 a Tier II vegetative vigor study using the Fontelis formulation. 

Additional data gaps for penthiopyrad that are considered low value to risk assessment include: 

 an avian reproduction toxicity study with the bobwhite quail using the penthiopyrad 

TGAI; and 

 an acute contact honeybee toxicity study using the penthiopyrad TGAI. 

Description of Importance of Data Gaps to Risk Assessment: 

As a result of the new 40 CFR Part 158 data requirements, avian acute oral data are now required 

for one passerine species in addition to either a waterfowl or upland game species for all new 

federal actions including Section 3 new chemical registrations. An avian oral toxicity study was 

submitted for a passerine species exposed to penthiopyrad; however, the submitted study was not 

able to establish a lethal dose due to significant (treatment related) regurgitation. However, 

because regurgitation was observed at every level and this effect is assumed to be a toxic 

response to the chemical exposure, an effect dose (ED50) was calculated using regurgitation as 

the effect, as a LD50 (lethal dose) could not be determined from the doses tested. In addition, the 

available acute oral toxicity data for the bobwhite quail, when compared to estimated 

environmental concentrations of penthiopyrad, indicate that LOCs are not exceeded for birds on 

an acute basis. Currently, EFED policy requires that the lack of acceptable passerine data be 

listed as a data gap. In the absence of data, risk will be assumed for passerine birds at the current 

application rates. However, due to the treatment-related regurgitation of the test compound for 

passerine species, a subacute dietary toxicity study using the passerine species is more 

appropriate to assess risk to non-target passerine bird species. Therefore, an acute dietary 

toxicity study with a passerine species using the penthiopyrad technical is recommended to 

characterize risk to passerine species. Submission of a protocol for the passerine subacute 
-Page 4 of 166- 

dietary study is also recommended. 

The log KOW of penthiopyrad (4.62) results in chronic risk LOC exceedances in KABAM for 

small mammals (shrews and moles) that consume benthic invertebrates. LOCs were not 

exceeded for mammals (minks and otters) that do not consume benthic invertebrates because 

these mammals consume fish and penthiopyrad is readily metabolized in fish. Study-derived 

metabolism rates in fish cannot be extrapolated to metabolism rates in benthic invertebrates since 

the latter may uptake and depurate compounds slower or faster than fish. Therefore, there is 

concern for bioaccumulation of penthiopyrad in benthic invertebrates. An oyster BCF study to 

address this concern would be valuable to the risk assessment and can be used to evaluate 

whether risk conclusions for small mammals can be revised. More specifically, uptake and 

depuration rates observed in an oyster BCF study are needed to represent metabolism/depuration 

in benthic invertebrates in exposure modeling with KABAM (metabolism is conservatively 

assumed not to occur in KABAM in the absence of measured values). If a submitted oyster BCF 

study indicates that metabolism in benthic invertebrates is substantial, then risk conclusions 

could change (i.e., chronic risk LOCs may not be exceeded for any mammals that consume 

benthic invertebrates). 

Estuarine/marine invertebrates are of particular concern as available acute toxicity data for the 

penthiopyrad technical indicate that estuarine/marine invertebrates are more sensitive than 

freshwater invertebrates on an acute exposure basis. However, no chronic toxicity data is 

available for estuarine/marine invertebrates. In the absence of data, an acute to chronic ratio 

(ACR) was derived using freshwater invertebrate toxicity data. Based on the estimated 

estuarine/marine invertebrate NOAEC using the ACR, the Agency’s chronic risk LOC is 

exceeded for the proposed penthiopyrad use on cranberries (using both the Tier I Rice model and 

additional provisional model refinements). There is an exposure potential for estuarine/marine 

invertebrates to be exposed to penthiopyrad from the proposed use on cranberries, as cranberries 

in Massachusetts are grown along Cape Cod, near coastal areas. As a result, there is concern for 

chronic risk to estuarine/marine invertebrates; therefore, an estuarine/marine invertebrate lifecycle toxicity study with the mysid would alleviate this concern. In the absence of additional 

data, chronic risk to estuarine/marine invertebrates will be estimated using the ACR derived from 

freshwater toxicity data. 

In addition, the Fontelis formulation was approximately 40 times more toxic to freshwater 

invertebrates than the penthiopyrad technical (TGAI), and no data on this formulation are 

available for saltwater invertebrates. Therefore, based on these results, the Fontelis formulation 

toxicity to estuarine/marine invertebrates is not known, and could potentially be more toxic than 

the freshwater invertebrates as was the case with the TGAI. There is the potential for 

estuarine/marine invertebrates to be exposed to the penthiopyrad Fontelis formulation (via spray 

drift); therefore to be able to fully characterize and describe the risk to estuarine/marine 

invertebrates associated with application of the Fontelis formulation acceptable estuarine/marine 

invertebrate toxicity studies would be valuable to this assessment. In the absence of 

estuarine/marine invertebrate acute toxicity data, risk to estuarine/marine invertebrates exposed 

to the Fontelis formulation via spray drift is presumed to exceed LOCs due to elevated toxicity of 

this formulation observed in other species and LOC exceedances based on TGAI toxicity data. 
-Page 5 of 166- 

Although estuarine/marine fish appear to be less sensitive to the Fontelis formulation compared 

with freshwater fish, the available estuarine/marine fish toxicity study was classified as 

supplemental and does not satisfy the data requirement for an acute estuarine/marine fish toxicity 

study with the penthiopyrad Fontelis formulation. Although the test material was mixed using a 

top-down mixer there is still concern that the samples may not represent only soluble 

penthiopyrad concentrations, and is not considered suitable for use within the risk assessment. 

There is the potential for estuarine/marine fish to be exposed to the penthiopyrad Fontelis 

formulation (via spray drift); therefore, to alleviate the uncertainty and to be able to fully 

characterize and describe the risk to estuarine/marine fish associated with application of the 

Fontelis formulation, an acceptable estuarine/marine fish toxicity study is needed. In the absence 

of estuarine/marine fish acute toxicity data, risk to estuarine/marine fish exposed to the Fontelis 

formulation via spray drift is presumed to exceed concern levels due to elevated toxicity of this 

formulation and due to LOC exceedances based on the TGAI toxicity data. 

Tier II seedling emergence and vegetative vigor studies would reduce the uncertainty regarding 

risk to listed species. Without a valid/definitive NOAEC value, risk to listed plant species would 

be assumed to an undefined area around the application site. However, there were less than 25% 

effects observed at a level above the highest proposed application rate, risks to non-listed plants 

and indirect effects to listed animals with no obligate relationships with plants can be discounted. 

However, risk to listed plants and animals with obligate relationships with plants cannot be 

discounted as direct risk to listed plants is assumed. Tier II seedling emergence and vegetative 

vigor toxicity studies with a defined, definitive NOAEC would alleviate uncertainty for listed 

species. Therefore, EFED recommends requesting a Tier II seedling emergence study using 

ryegrass, wheat, and tomato, and a Tier II vegetative vigor study using wheat and soybean. 

Available avian chronic toxicity data for the penthiopyrad technical indicate that the control 

mortality in this study (12.5%; 3 females and 1 male out of 16 pairs) exceeded the limit for an 

acceptable study (OCSPP, form. OPTTS 850.2300). The effects that were seen in the necropsies 

of the dead control birds also raise concerns relating to potential impacts on reproduction of the 

other control birds, resulting in an overall decreased eggs laid mean for the control birds. As a 

result, risk may potentially be underestimated. Submittal of an acceptable avian reproduction 

toxicity study using bobwhite quail for penthiopyrad technical, completed in accordance with 

OPPTS 850.2300 would eliminate the data gap, however, the available information for the 

mallard duck is sufficient to complete estimation of risk to non-target birds (surrogate for 

terrestrial-phase amphibians and reptiles) on a chronic exposure basis, and therefore, a new study 

is not needed at this time. EFED recommends not requesting a new study, as an acceptable 

mallard avian reproduction study is available. However, the avian reproduction guideline is not 

fulfilled and EFED recommends that the Agency reserve the right to request a new study if it is 

deemed necessary in the future. 

The acute contact honeybee study with the penthiopyrad technical (TGAI) does not satisfy the 

data requirement, as a negative control was not tested concurrently with the solvent control 

during this study. Submittal of an acceptable honeybee acute contact toxicity study for 

penthiopyrad technical, completed in accordance with OPPTS 850.3020 would eliminate the data 

gap. However, as no effects were seen in the treatment group or the solvent control, EFED 

believes that a new study would not likely be of high value to this assessment. Therefore, the 
-Page 6 of 166- 

acute contact honeybee study using the penthiopyrad technical (TGAI) guideline is not fulfilled 

and EFED recommends that the Agency reserve the right to request a new study if it is deemed 

necessary in the future. 

 
-Page 7 of 166- 

Environmental Fate and Ecological Risk Assessment for the 

Registration of the New Chemical Penthiopyrad (MTF-753) 

Penthiopyrad

CAS 183675-82-3 PC Code 090112 

Prepared by:

Greg Orrick, Environmental Scientist 

Christina Wendel, Biologist 

U.S. Environmental Protection Agency 

Office of Pesticide Programs 

Environmental Fate and Effects Division 

Environmental Risk Branch II 

1200 Pennsylvania Ave., NW 

Mail Code 7507P 

Washington, DC 20460

Reviewed by: 

Kristina Garber, Senior Biologist 

James Lin, Environmental Engineer 

Jean Holmes, Risk Assessment Process Leader 

Brian Anderson, Branch Chief 
-Page 8 of 166- 

Table of Contents 

1. Executive Summary ........................................................................................................................................... 10

1.1. Nature of Chemical Stressor ..................................................................................................................... 10

1.2. Exposure Characterization ........................................................................................................................ 10

1.3. Effects Characterization ........................................................................................................................... 11

1.4. Potential Risks to Non-target Organisms.................................................................................................. 12

1.5. Data Gaps and Uncertainties .................................................................................................................... 14

2. Problem Formulation ........................................................................................................................................ 17

2.1. Nature of Regulatory Action .................................................................................................................... 17

2.2. Stressor Source and Distribution .............................................................................................................. 18

2.2.1. Nature of the Chemical Stressor ........................................................................................................ 18

2.2.2. Overview of Pesticide Usage ............................................................................................................. 18

2.3. Receptors ................................................................................................................................................. 19

2.3.1. Aquatic and Terrestrial Effects .......................................................................................................... 19

2.3.2. Ecosystems Potentially at Risk .......................................................................................................... 19

2.4. Assessment Endpoints .............................................................................................................................. 20

2.5. Conceptual Model ..................................................................................................................................... 20

2.5.1. Risk Hypotheses ................................................................................................................................ 20

2.5.2. Conceptual Diagram .......................................................................................................................... 20

2.6. Analysis Plan .............................................................................................................................................. 21

2.6.1. Residues of Concern .......................................................................................................................... 21

2.6.2. Measures of Exposure ....................................................................................................................... 22

2.6.3. Measures of Effect ............................................................................................................................. 26

2.6.4. Integration of Exposure and Effects .................................................................................................. 27

3. Analysis ............................................................................................................................................................ 28

3.1. Use Characterization................................................................................................................................. 28

3.2. Exposure Characterization ........................................................................................................................ 31

3.2.1. Environmental Fate and Transport Characterization ......................................................................... 31

3.2.1.1. Transport and Mobility ............................................................................................................ 32

3.2.1.2. Degradation .............................................................................................................................. 33

3.2.1.3. Bioaccumulation ...................................................................................................................... 34

3.2.1.4. Field Studies ............................................................................................................................ 35

3.2.1.5. Environmental Degradates ....................................................................................................... 36

3.2.2. Measures of Aquatic Exposure .......................................................................................................... 38

3.2.2.1. Surface Water Exposure .......................................................................................................... 38

3.2.2.2. Ground Water Exposure .......................................................................................................... 46

3.2.2.3. Aquatic Bioaccumulation ......................................................................................................... 47

3.2.3. Measures of Terrestrial Exposure ...................................................................................................... 49

3.2.3.1. Terrestrial Wildlife .................................................................................................................. 49

3.3. Ecological Effects Characterization ......................................................................................................... 51

3.3.1. Aquatic Toxicity Characterization ..................................................................................................... 52

3.3.2.1. Toxicity to Freshwater Fish ..................................................................................................... 54

3.3.2.2. Toxicity to Freshwater Invertebrates ....................................................................................... 56

3.3.2.3. Toxicity to Estuarine/Marine Fish ........................................................................................... 61

3.3.2.4. Toxicity to Estuarine/Marine Invertebrates ............................................................................. 62

3.3.2.5. Toxicity to Aquatic Plants ....................................................................................................... 63

3.3.2 Terrestrial Effects Characterization ................................................................................................... 66

3.3.2.1. Toxicity to Birds ...................................................................................................................... 68

3.3.2.2. Toxicity to Mammals ............................................................................................................... 70

3.3.2.3. Toxicity to Terrestrial Invertebrates and Beneficial Insects .................................................... 72

3.3.2.4. Toxicity to Terrestrial Plants ................................................................................................... 77

4. Risk Characterization ......................................................................................................................................... 78

4.1 Risk Estimation ........................................................................................................................................ 78
-Page 9 of 166- 

4.1.1. Aquatic Organisms ................................................................................................................................... 78

4.1.1.1. Aquatic Animals ...................................................................................................................... 79

4.1.1.2. Aquatic Plants .......................................................................................................................... 82

4.1.2. Terrestrial Organisms ............................................................................................................................... 83

4.1.2.1. Birds ......................................................................................................................................... 83

4.1.2.2. Mammals ................................................................................................................................. 84

4.1.2.3. Terrestrial Invertebrates ........................................................................................................... 85

4.1.2.4. Non-target Terrestrial and Semi-Aquatic Plants ...................................................................... 85

4.2. Risk Description ....................................................................................................................................... 86

4.2.1. Risks to Aquatic Animals .................................................................................................................. 87

4.2.1. Risks to Aquatic Plants ...................................................................................................................... 89

4.2.2. Risks to Terrestrial Organisms .......................................................................................................... 90

4.2.2.1. Birds, Terrestrial-Phase Amphibians and Reptiles ........................................................................... 90

4.2.2.2. Mammals .......................................................................................................................................... 92

4.2.2.3. Terrestrial Invertebrates.................................................................................................................... 96

4.2.2.4. Terrestrial Plants ............................................................................................................................... 98

5. Federally Threatened and Endangered (Listed) Species Concerns .................................................................... 99

5.1. Action Area .............................................................................................................................................. 99

5.2. Taxonomic Groups Potentially at Risk ................................................................................................... 100

5.2.1. Probit Dose-Response Analysis ...................................................................................................... 102

5.2.2. Listed Species Occurrence Associated with Penthiopyrad Use ....................................................... 104

6. References ........................................................................................................................................................ 105

6.1. Submitted Product Chemistry and Environmental Fate Studies ............................................................. 108

6.2. Submitted Ecotoxicity Studies ................................................................................................................ 111

6.3. Chlorothalonil Ecotoxicity Studies Discussed (Previously Submitted) .................................................. 122

Appendix A. STIR v.1.0 (Screening Tool for Inhalation Risk) Input/Output .......................................................... 124

Appendix B. Chemical Names, Structures, and Maximum Reported Amounts of Penthiopyrad and Its Degradates.

 ................................................................................................................................................................................... 126

Appendix C. Aquatic Model Input/Output Data. ...................................................................................................... 130

Appendix D. Example T-REX Output for Penthiopyrad. ......................................................................................... 135

Appendix E. Penthiopyrad Degradate Toxicity Summary. ....................................................................................... 136

Appendix F. Comparison of Treoris Formulation and the Chlorothalonil Active Ingredient (TGAI) Toxicity. ...... 140

Appendix G. Provisional Tier I Cranberry Model Equations. .................................................................................. 141

Appendix H. Submitted Ecological Effects Studies for Penthiopyrad and Analysis of Data Gaps. ......................... 144

Appendix I. Submitted Environmental Fate Studies for Penthiopyrad. .................................................................... 164
10 

1. Executive Summary 

 1.1. Nature of Chemical Stressor 

Penthiopyrad (i.e., MTF-753, DPX-LEM17, or (RS)-N-[2-(1,3-dimethylbutyl)-3-thienyl]-1-

methyl-3-(trifluoromethyl)-pyrazole-4-carboxamide; CAS# 183675-82-3), is a pyrazole 

carboxamide in the succinate dehydrogenase inhibitor (SDHI) class of fungicides. The 

compound is nonvolatile, lipophilic, moderately mobile in soil, and is not expected to 

bioaccumulate in fish. Penthiopyrad is proposed for use on a wide range of agricultural crops as 

well as turf and landscape ornamentals. 

Four end-use formulations of penthiopyrad are proposed for registration in the United States. 

These include Fontelis (20% active ingredient (a.i.)), a suspension concentrate (SC) for a range 

of agricultural uses; Vertisan (20% a.i.), an emulsifiable concentrate (EC) for a range of 

agricultural uses; Treoris (8.9% a.i.), a suspension concentrate (SC) co-formulated with 

chlorothalonil (22.3% a.i.) for a range of agricultural uses; and Velista (50% a.i.), a water 

dispersible granule (WG) for use on turf and landscape ornamentals. 

The proposed maximum single and annual application rates for penthiopyrad are 0.95 and 2.9 

pounds of active ingredient per acre (lbs a.i./A), respectively, on turf (Velista). Fontelis, 

Vertisan and Treoris each have proposed maximum single and annual application rates of 0.39 

and 0.94 lbs a.i./A, respectively for selected agricultural uses. 

 1.2. Exposure Characterization 

Penthiopyrad is a racemic mixture of enantiomers that undergo slight enantiomeric selectivity 

(mostly to the S-isomer) in studied soils. The compound is non-volatile, lipophilic, and 

moderately mobile in soil. Penthiopyrad is not expected to bioaccumulate in fish; however, the 

compound may bioaccumulate in benthic invertebrates. Indirect photolysis in soil is the fastest 

route of penthiopyrad degradation (half-life of 6.4 days); however, the compound persists in 

many compartments of the environment, dissipating in shaded and aquatic areas by slow aerobic 

biodegradation (half-life of 60-406 days) and slow leaching (Freundlich organic carbonnormalized partition coefficient (KFOC) range of 560-900 L/kgOC). Penthiopyrad does not 

undergo hydrolysis or photolysis in water bodies. The compound persists in anaerobic 

conditions. Depending on the soil type, the compound may slowly move to ground water via 

leaching and may move to surface water bodies via spray drift, runoff of dissolved or sorbed 

residues, and transport of dissolved residues in base flow from shallow ground water. Terrestrial 

field dissipation study results are relatively consistent with those of the laboratory studies, 

showing that the chemical dissipates by degradation and slow leaching, with dissipation halflives ranging from 2.2 to 44 days (laboratory study half-lives ranged from 6.2 to >365 days). 

Major identified environmental degradates of penthiopyrad are PAM, PCA, DM-PCA, and 

carbon dioxide (chemical names and structures are provided in Appendix B). Additional minor 

degradates were increasing in concentration at study termination and may have become major 

degradates if the studies were continued. PAM, PCA, and DM-PCA are cleavage products that 

retain the pyrazole ring of the parent compound. These three major degradates were persistent 
11

and highly mobile in studies of penthiopyrad. Compounds with trifluoromethyl groups, such as 

penthiopyrad, may slowly form hydrofluorocarbons in the environment. 

Aquatic exposure estimates reflect environments where indirect photolysis does not occur. 

Where indirect photolysis occurs, exposure estimates and associated RQs may be 38-43% lower 

than reported in this assessment. 

 1.3. Effects Characterization 

Penthiopyrad is classified as moderately to highly toxic to freshwater fish and freshwater 

invertebrates and moderately toxic to estuarine/marine fish and estuarine/marine invertebrates on 

an acute exposure basis. Mortality and sublethal effects were observed in most of the acute 

aquatic animal studies for penthiopyrad. Observed sublethal effects included loss of equilibrium, 

lying on the bottom of the test chamber, lethargy, surfacing, hyperventilation, haemorrhage, and 

reduced activity. The available acute toxicity data for the Treoris (DPX-QFA61 SC) 

formulation, which contains 8.91% penthiopyrad and 22.3% chlorothalonil, show that it is 

approximately 28 to 137 times more toxic than the penthiopyrad active ingredient alone to 

freshwater fish, freshwater invertebrates, and aquatic non-vascular plants (Appendix F). 

Although the Treoris formulation is more toxic than technical grade penthiopyrad, further 

examination of the available data indicate that chlorothalonil, not penthiopyrad, likely accounts 

for the toxicity of this formulation. In addition, the available toxicity data for the Fontelis (DPXLEM17 20SC) formulation which contains 20% penthiopyrad show that it is approximately 42 

times more toxic than the penthiopyrad technical grade active ingredient to freshwater 

invertebrates. Chronic effects to freshwater fish were based on treatment-related effects on the 

larval survival and growth (total length and weight). Chronic effects to freshwater invertebrates 

(Daphnia) were based on treatment-related reductions in first-generation survival (immobility), 

reproduction (mean number of live offspring per surviving adult), and terminal length. Benthic 

sediment toxicity testing with spiked sediment indicates that the compound does partition to 

sediment. Exposure of benthic invertebrates resulted in a 34% reduction in emergence rate. All 

available aquatic toxicity data show that metabolites of penthiopyrad are less toxic to aquatic 

animals and plants than the parent penthiopyrad. 

Penthiopyrad is classified as practically non-toxic to avian species on an acute oral and subacute 

dietary-exposure basis; however, treatment-related regurgitation was observed in zebra finch 

dosed with technical penthiopyrad. The lowest no observed adverse effect [dietary] concentration 

(NOAEC) in an avian reproduction study (1520 mg a.i./kg diet) was based on a reduction in the 

number of eggs laid and eggs set by mallard ducks. Penthiopyrad is classified as practically nontoxic to mammals on an acute oral exposure basis. A two-generation reproduction study of rats 

resulted in a no observed adverse effect level (NOAEL) of 38 mg a.i./kg-bw/day based on 

reduced body weight gain in first generation (F1) adult males, increased liver weight in parental 

(P) and F1 adult females and increased relative adrenal weight with increased incidence of 

cortical hypertrophy in F1 females. Some sublethal effects were observed in the acute terrestrial 

animal studies for penthiopyrad, including body weight gain in the subacute dietary study with 

the bobwhite quail. 

Based on the available data, direct adverse effects to terrestrial invertebrates are considered low 

for penthiopyrad technical, but not for the formulations. It is possible that adverse effects to 
12

terrestrial invertebrates, including pollinators and beneficial insects, may occur based on 

exposure to the Fontelis, Vertisan, and/or Treoris formulated products in and around the use 

areas of the proposed uses of penthiopyrad. However, at this time, risk to these taxa cannot be 

quantified. 

Results of the Tier I seedling emergence and vegetative vigor studies with the Fontelis 

formulation indicate that there were significant effects that were less than 25% in magnitude 

relative to controls observed at a level above the highest proposed application rate, risks to nonlisted plants and indirect effects to listed animals with no obligate relationships with plants are 

below concern levels. Risk to listed plants and animals with obligate relationships with plants 

are above concern levels. Ryegrass, wheat (monocots), tomato, and soybean (dicots) exhibited 

treatment related, statistically significant, reductions at the limit concentration relative to the 

negative control. Although Tier II studies are not triggered becuase no effects were greater than 

25%, Tier II studies would reduce the uncertainty regarding Endangered Species assessments. 

Without a valid/definitive NOAEC value, risk to listed plant species would be assumed to an 

undefined area around the application site. The results of these tests indicate that some terrestrial 

plants may be sensitive to penthiopyrad exposure. 

1.4. Potential Risks to Non-target Organisms 

The results of this assessment indicate that the proposed uses of penthiopyrad (except use on 

canola) result in LOC exceedances for listed freshwater fish (a surrogate for aquatic-phase 

amphibians). The potential for acute effects on listed estuarine/marine fish and invertebrates (via 

spray drift from the Fontelis formulation) cannot be precluded. The proposed use on cranberries 

results in additional LOC exceedances, including exceedances for acute effects on listed and 

non-listed freshwater fish (a surrogate for aquatic-phase amphibians); acute effects on listed 

freshwater invertebrates, estuarine/marine fish and invertebrates; chronic effects to freshwater 

fish and estuarine/marine invertebrates2

; and acute effects on listed estuarine/marine fish and 

invertebrates (via spray drift from the Fontelis formulation). All proposed uses of penthiopyrad 

result in LOC exceedances for chronic effects on listed and non-listed mammals. In addition, 

due to effects seen at the single application rate for both terrestrial monocot and dicot plant 

species in the seedling emergence and vegetative vigor toxicity tests, risk to terrestrial plants and 

animals with obligate relationships with plants are presumably above concern levels. 

Although concern levels were not exceeded for risk to aquatic plants, birds, terrestrial-phase 

amphibians, and reptiles, indirect effects to these taxa are possible, given the potential for 

adverse acute effects to freshwater fish, aquatic-phase amphibians, estuarine/marine fish and 

invertebrates (via spray drift of the Fontelis formulation, which cannot be precluded), chronic 

effects to terrestrial mammals and adverse effects to terrestrial plants. Potential effects include, 

but are not limited to, reduction in food resources, decrease in cover, change in water quality 

parameters, and loss of breeding/nesting habitat. Identified potential direct and indirect risks to 

listed species that may result from the proposed uses of penthiopyrad (except use on cranberries) 

are summarized in Table 1.1. The potential direct and indirect risk to listed species that may 

 

2

 Based on the refined cranberry model calculated EEC values, and derived acute and chronic RQs. The Tier I rice 

model calculated EEC value results in potential direct adverse acute and chronic effects to all aquatic organisms, as 

well as aquatic non-vascular plants. 
13

result from the proposed cranberry use is summarized in Table 1.1a. In addition, it is possible 

that adverse effects to terrestrial invertebrates, including pollinators and beneficial insects, may 

occur based on exposure to the Fontelis, Vertisan, and/or Treoris formulated products in and 

around the use areas of the proposed uses of penthiopyrad. However, at this time, risk to these 

taxa cannot be quantified. Therefore, no taxonomic groups could be excluded from being at risk 

from either direct or indirect effects at this time. 

Table 1.1. Potential Effects to Federally Listed Taxa Associated with Direct or Indirect 

Effects from the Proposed Uses of Penthiopyrad (all uses except cranberries).

Listed Taxon Direct 

Effects Uses of Concern Indirect Effects Uses of Concern 

Terrestrial and semiaquatic plants - 

monocots 

Yes All uses Yes2 All uses 

Terrestrial and semiaquatic plants - dicots Yes All uses Yes2 All uses 

Birds No None Yes1,2,3 All uses 

Terrestrial-phase 

amphibians No None Yes1,2,3 All uses 

Reptiles No None Yes1,2,3 All uses 

Mammals Yes All uses Yes1,3 All uses 

Terrestrial invertebrates Yesa All uses Yes1 All uses 

Aquatic vascular and 

non-vascular plants No None Yes3

 All uses 

Freshwater fish Yes All uses except canola Yes1,3 All uses 

Aquatic-phase 

amphibians Yes All uses except canola Yes1,3 All uses 

Freshwater 

invertebrates No None Yes1,3 All uses 

Mollusks No None Yes1,3 All uses 

Marine/estuarine fish Yesb All uses Yes1,3 All uses 

Marine/estuarine 

invertebrates Yesb

 All uses Yes1,3 All uses 

Sediment-dwelling 

organisms No None Yes3

 All uses 

a

 RQs were not calculated due to lack of a standard quantification methodology for non-listed species. Therefore, the 

‘LOC exceedance’ was based on lines of evidence including application rate, toxicity data (both pollinators and 

beneficial insects), and the mode of action of penthiopyrad. 

b Risk cannot be precluded via spray drift of the Fontelis formulation to water bodies with lack of data for the 

Fontelis formulation for estuarine/marine fish and invertebrates.

Potential indirect effects on a taxon attributable to: 1

 direct effects on plants (terrestrial and semi-aquatic) 2

 direct chronic effects on mammals 

3

 direct acute effects on freshwater fish and aquatic-phase amphibians 
14

Table 1.1a. Potential Effects to Federally Listed Taxa Associated with Direct or Indirect 

Effects from the Proposed Uses of Penthiopyrad on Cranberries*. 

Listed Taxon Direct 

Effects Uses of Concern Indirect 

Effects Uses of Concern 

Terrestrial and semiaquatic plants - 

monocots 

Yes All uses Yes2 All uses 

Terrestrial and semiaquatic plants - dicots Yes All uses Yes2 All uses 

Birds No None Yes1,2,3 All uses 

Terrestrial-phase 

amphibians No None Yes1,2,3 All uses 

Reptiles No None Yes1,2,3 All uses 

Mammals Yes All uses Yes1,3 All uses 

Terrestrial invertebrates Yesa All uses Yes1 All uses 

Aquatic vascular and 

non-vascular plants No None Yes3

 All uses 

Freshwater fish Yes Cranberry Yes1,3 All uses 

Aquatic-phase 

amphibians Yes Cranberry Yes1,3 All uses 

Freshwater 

invertebrates Yes Cranberry Yes1,3 All uses 

Mollusks Yes Cranberry Yes1,3 All uses 

Marine/estuarine fish Yesb Cranberry Yes1,3 All uses 

Marine/estuarine 

invertebrates Yesb

 Cranberry Yes1,3 All uses 

Sediment-dwelling 

organisms No None Yes3

 All uses 

* Based on the refined cranberry model calculated EEC values, and derived acute and chronic RQs. The Tier I rice 

model calculated EEC value results in potential direct adverse acute and chronic effects to all aquatic organisms, as 

well as aquatic non-vascular plants. 

a

 RQs were not calculated due to lack of a standard quantification methodology for non-listed species. Therefore, the 

‘LOC exceedance’ was based on lines of evidence including application rate, toxicity data (both pollinators and 

beneficial insects), and the mode of action of penthiopyrad. 

b Risk cannot be precluded via spray drift of the Fontelis formulation to water bodies with lack of data for the 

Fontelis formulation for estuarine/marine fish and invertebrates.

Potential indirect effects on a taxon attributable to: 1

 direct effects on plants (terrestrial and semi-aquatic) 2

 direct chronic effects on mammals 

3

 direct acute effects on freshwater fish and invertebrates, aquatic-phase amphibians, estuarine/marine fish and 

invertebrates; and direct chronic effects on freshwater fish and estuarine/marine invertebrates (based on the refined 

cranberry model calculated EEC values, and derived acute and chronic RQs). 

 1.5. Data Gaps and Uncertainties 

As a result of the new 40 CFR Part 1583

 data requirements, avian acute oral data are now 

required for one passerine species in addition to either a waterfowl or upland game species for all 

new federal actions including Section 3 new chemical registrations. An avian oral toxicity study 

was submitted for a passerine species exposed to penthiopyrad; however, the submitted study 

was not able to establish a lethal dose due to treatment-related regurgitation. In addition, the 

 

3

 CFR 2011. http://ecfr.gpoaccess.gov/cgi/t/text/textidx?c=ecfr&sid=55aa15659b5f49d286f1a93853dc7a2d&tpl=/ecfrbrowse/Title40/40cfr158_main_02.tpl 
15

available acute oral toxicity data for the bobwhite quail, when compared to estimated 

environmental concentrations of penthiopyrad, indicate that LOCs are not exceeded for birds on 

an acute exposure basis. Because an apparent treatment-related regurgitation occurred in the 

submitted passerine study, a subacute dietary toxicity study using the passerine species and the 

penthiopyrad TGAI is more appropriate to assess risk to non-target passerine bird species. 

In addition, other data needs and/or data gaps needed to obtain a complete risk picture for 

penthiopyrad include: 

 a passerine subacute dietary study using the penthiopyrad TGAI 

 an oyster BCF study using the penthiopyrad TGAI; 

 an estuarine/marine invertebrate (mysid) chronic toxicity study using the penthiopyrad 

TGAI; 

 estuarine/marine invertebrates (mysid and oyster) acute toxicity studies using the 

Fontelis formulation; 

 an estuarine/marine fish acute toxicity study using the Fontelis (DPX-LEM17 20SC) 

formulation; 

 a Tier II seedling emergence study using the Fontelis formulation; and 

 a Tier II vegetative vigor study using the Fontelis formulation. 

The log KOW of penthiopyrad (4.62) results in chronic risk LOC exceedances in KABAM for 

small mammals (shrews and moles) that consume benthic invertebrates. LOCs were not 

exceeded for mammals (minks and otters) that do not consume benthic invertebrates because 

these mammals consume fish and penthiopyrad is readily metabolized in fish. Study-derived 

metabolism rates in fish cannot be extrapolated to metabolism rates in benthic invertebrates since 

the latter may uptake and depurate compounds slower or faster than fish. Therefore, there is 

concern for bioaccumulation of penthiopyrad in benthic invertebrates. An oyster BCF study to 

address this concern would be valuable to the risk assessment and can be used to evaluate 

whether risk conclusions for small mammals can be updated. More specifically, uptake and 

depuration rates observed in an oyster BCF study are needed to represent metabolism/depuration 

in benthic invertebrates in exposure modeling with KABAM (metabolism is conservatively 

assumed not to occur in KABAM in the absence of measured values). If a submitted oyster BCF 

study indicates that metabolism in benthic invertebrates is substantial, then risk conclusions 

could change (i.e., chronic risk LOCs may not be exceeded for any mammals that consume 

benthic invertebrates). 

Estuarine/marine invertebrates are of particular concern as available acute toxicity data for the 

penthiopyrad technical indicate that estuarine/marine invertebrates are more sensitive than 

freshwater invertebrates on an acute exposure basis. However, no chronic toxicity data is 

available for estuarine/marine invertebrates. In the absence of data, an acute to chronic ratio 

(ACR) was derived using freshwater invertebrate toxicity data. Based on the estimated 

estuarine/marine invertebrate NOAEC using the ACR, the Agency’s chronic risk LOC is 

exceeded for the proposed penthiopyrad use on cranberries (using both the Tier I Rice model and 

additional provisional model refinements). There is an exposure potential for estuarine/marine 

invertebrates to be exposed to penthiopyrad from the proposed use on cranberries, as cranberries 

in Massachusetts are grown along Cape Cod, near coastal areas. As a result, there is concern for 

chronic risk to estuarine/marine invertebrates; therefore, an estuarine/marine invertebrate life-
16

cycle toxicity study with the mysid would alleviate this concern. In the absence of additional 

data, chronic risk to estuarine/marine invertebrates will be estimated using the ACR derived from 

freshwater toxicity data. 

In addition, the Fontelis formulation was approximately 40 times more toxic to freshwater 

invertebrates than the penthiopyrad technical (TGAI), and no data on this formulation are 

available for saltwater invertebrates. Therefore, based on these results, the Fontelis formulation 

toxicity to estuarine/marine invertebrates is not known, and could potentially be more toxic than 

the freshwater invertebrates as was the case with the TGAI. There is the potential for 

estuarine/marine invertebrates to be exposed to the penthiopyrad Fontelis formulation (via spray 

drift); therefore to be able to fully characterize and describe the risk to estuarine/marine 

invertebrates associated with application of the Fontelis formulation acceptable estuarine/marine 

invertebrate toxicity studies would be valuable to this assessment. In the absence of 

estuarine/marine invertebrate acute toxicity data, risk to estuarine/marine invertebrates exposed 

to the Fontelis formulation via spray drift is presumed to exceed LOCs due to elevated toxicity 

of this formulation observed in other species and LOC exceedances based on TGAI toxicity data. 

Although estuarine/marine fish appear to be less sensitive to the Fontelis formulation compared 

with freshwater fish, the available estuarine/marine fish toxicity study was classified as 

supplemental and does not satisfy the data requirement for an acute estuarine/marine fish toxicity 

study with the penthiopyrad Fontelis formulation. Although the test material was mixed using a 

top-down mixer there is still concern if the samples represent only soluble penthiopyrad 

concentrations, and is not considered suitable for use within the risk assessment. There is the 

potential for estuarine/marine fish to be exposed to the penthiopyrad Fontelis formulation (via 

spray drift). To alleviate the uncertainty and to be able to fully characterize and describe the risk 

to estuarine/marine fish associated with application of the Fontelis formulation, an acceptable 

estuarine/marine fish toxicity study is needed. In the absence of estuarine/marine fish acute 

toxicity data, risk to estuarine/marine fish exposed to the Fontelis formulation via spray drift is 

presumed to exceed concern levels due to elevated toxicity of this formulation and due to to 

LOC exceedances based on the TGAI toxicity data. 

Tier II seedling emergence and vegetative vigor studies would reduce the uncertainty regarding 

risk to listed species. Without a valid/definitive NOAEC value, risk to listed plant species would 

be assumed to an undefined area around the application site. However, there were less than 25% 

effects observed at a level above the highest proposed application rate, risks to non-listed plants 

and indirect effects to listed animals with no obligate relationships with plants do not exceed 

LOCs. However, risk to listed plants and animals with obligate relationships with plants do 

exceed listed species LOCs. Tier II seedling emergence and vegetative vigor toxicity studies 

with ryegrass, wheat, tomato, and soybean with a defined, definitive NOAEC would alleviate 

uncertainty for listed species. 

In addition, other data gaps for penthiopyrad that are of low value to risk assessment include: 

 an avian reproduction toxicity study with the bobwhite quail using the penthiopyrad 

TGAI; and 

 an acute contact honeybee toxicity study using the penthiopyrad TGAI. 
17

Available avian chronic toxicity data for the penthiopyrad technical indicate that the control 

mortality in this study (12.5%; 3 females and 1 male out of 16 pairs) exceeded the limit for an 

acceptable study (OCSPP, form. OPTTS 850.2300). The effects that were seen in the necropsies 

of the dead control birds also raise concerns relating to potential impacts on reproduction of the 

other control birds, resulting in an overall decreased eggs laid mean for the control birds. As a 

result, risk may potentially be underestimated. Submittal of an acceptable avian reproduction 

toxicity study using bobwhite quail for penthiopyrad technical, completed in accordance with 

OPPTS 850.2300 would eliminate the data gap, however, the available information for the 

mallard duck is sufficient to complete estimation of risk to non-target birds (surrogate for 

terrestrial-phase amphibians and reptiles) on a chronic exposure basis, and therefore, a new study 

is not needed at this time. 

The acute contact honeybee study with the penthiopyrad technical (TGAI) does not satisfy the 

data requirement, as a negative control was not tested concurrently with the solvent control 

during this study. Submittal of an acceptable honeybee acute contact toxicity study for 

penthiopyrad technical, completed in accordance with OPPTS 850.3020 would eliminate the data 

gap, however, the observed toxicity appears to be low for the technical grade material, and a new 

study would not likely be of high value to this assessment. 

2. Problem Formulation 

The purpose of this problem formulation is to provide the foundation for the environmental fate 

and ecological risk assessment for the registration of the new chemical penthiopyrad. This 

problem formulation sets the objectives for the risk assessment, establishes a risk hypothesis and 

conceptual model depicting risk, and provides a plan for analyzing the data and characterizing 

the risk associated with the proposed uses of penthiopyrad (USEPA, 1998a). 

 2.1. Nature of Regulatory Action 

This assessment was prepared to support the new chemical registration of penthiopyrad. As a 

new fungicide being proposed for use in the United States, the U.S. Environmental Protection 

Agency (EPA or the Agency) is required under the Federal Insecticide, Fungicide, and 

Rodenticide Act (FIFRA) to ensure that penthiopyrad does not have the potential to cause 

unreasonable adverse effects to the environment. In addition to non-target animals and plants, 

potential effects to listed species (i.e., species on the federal list of endangered and threatened 

wildlife and plants) are also considered under the Endangered Species Act (ESA) in order to 

ensure that the registration of penthiopyrad is not likely to jeopardize the continued existence of 

such listed species or adversely modify their critical habitat. In order to meet the requirements of 

FIFRA and the ESA, this assessment follows EPA guidance on conducting ecological risk 

assessments (USEPA, 1998a) and Office of Pesticide Program’s Overview Document, which 

contains guidance for assessing pesticide risks to non-target and listed organisms (USEPA, 

2004). 

The end result of the EPA pesticide registration process (i.e., the FIFRA regulatory action) is an 

approved product label. The label is a legal document that stipulates how and where a given 

pesticide may be used. Product labels (also known as end-use labels) describe the formulation 
18

type (e.g., liquid or granular), acceptable methods of application, approved use sites, and any 

restrictions on how applications may be conducted. Therefore, the use, or potential use, 

described by the pesticide’s labels is considered “the action” being assessed. 

 2.2. Stressor Source and Distribution 

 2.2.1. Nature of the Chemical Stressor 

Penthiopyrad is a broad-spectrum fungicide with preventative, curative, and some systemic 

activity intended to control foliar and soil-borne plant diseases caused by many Ascomycete and 

Basidiomycete fungi (MRID 47735219, 48081904). The compound is a pyrazole carboxamide 

in the succinate dehydrogenase inhibitor (SDHI) class of fungicides and stops spore germination, 

inhibits mycelium growth, and has antisporulant activity (MRID 48081904). SDHI compounds 

bind to the protein succinate:ubiquinone reductase in complex II of the electron transport chain, 

which inhibits two critical respiratory pathways, the citric acid cycle and mitochondrial electron 

transport (MRID 48081904). To clarify penthiopyrad’s partial systemic activity, the compound 

is systemic in xylem, flowing throughout plants following root uptake (MRID 47735219); 

however, penthiopyrad only undergoes translaminar distribution from treated to untreated leaf 

surfaces following foliar application, with no systemic movement in phloem (MRID 47735219). 

Mitsui Chemicals, Inc. and E. I. du Pont de Nemours and Company are applying to register 

penthiopyrad in the United States as a technical grade active ingredient (TGAI) and in 

formulated end-use products, respectively. Four end-use products currently proposed for 

registration in the United States include the following: 

1. Fontelis: 20% penthiopyrad; agricultural uses proposed 

2. Vertisan: 20% penthiopyrad; agricultural uses proposed 

3. Treoris: 8.9% penthiopyrad and 22.3% chlorothalonil; agricultural uses proposed 

4. Velista: 50% penthiopyrad; use on turf and landscape ornamentals proposed 

These end-use products include proposed uses on alfalfa, brassica vegetables, bulb vegetables, 

canola, cereals (excluding rice and wild rice), cotton, cucurbits, fruiting vegetables, leafy 

vegetables, low growing berries (including cranberries), peanuts, pome fruits, root and tuber 

vegetables and leaves, stone fruits, succulent and dry legumes, sunflowers, tree nuts (including 

pistachios and excluding pecans), turf (including sod farms and any landscaped areas) and 

landscape ornamentals. All of the penthiopyrad end-use products may be foliarly applied. They 

may be applied via ground or aerial application methods, with the exceptions of rhubarb, 

landscape ornamentals, and turf, which may be applied only by ground methods. Also, selected 

agricultural uses may be applied via chemigation or seedling methods. 

 2.2.2. Overview of Pesticide Usage 

Usage data are not available for penthiopyrad because it is a new active ingredient proposed for 

use in the United States, the United Kingdom, Canada, and Australia. 
19

 2.3. Receptors 

 2.3.1. Aquatic and Terrestrial Effects 

Table 2.1 provides examples of taxonomic groups and the surrogate species tested to evaluate 

the potential ecological effects of pesticides to these non-target taxonomic groups. Within each 

of these very broad taxonomic groups, a measure of effect from either acute or chronic exposure 

is selected from the available test data. Toxicological data generated from surrogate test species, 

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

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

 

Table 2.1. Example Taxonomic Groups and Surrogate Test Species Evaluated for 

Assessing Potential Ecological Effects of Penthiopyrad. 

Taxonomic Group Example(s) of Surrogate Species 

Birds, terrestrial-phase amphibians, and reptiles1 Mallard duck (Anas platyrhynchos) 

Bobwhite quail (Colinus virginianus) 

Zebra finch (Poephila guttata) 

Mammals Wistar rat (Ratus norvegicus) 

Insects Honey bee (Apis mellifera L.) 

Freshwater fish, and aquatic-phase amphibitans2 Bluegill sunfish (Lepomis macrochirus) 

Rainbow trout (Oncorhynchus mykiss) 

Fathead minnow (Pimephales promelas) 

Freshwater invertebrates Water flea (Daphnia magna) 

Midge (Chironomus riparius) 

Estuarine/marine fish Sheepshead minnow (Cyprinodon variegatus) 

Estuarine/marine invertebrates Mysid (Americamysis bahia) 

Eastern oyster (Crassostrea virginica) 

Terrestrial plants Monocots – corn (Zea mays)

3

Dicots – soybean (Glycine max) 

Aquatic plants and algae Duckweed (Lemna gibba) 

Freshwater algae (Pseudokirchneriella subcapita) 1

 Birds represent surrogates for terrestrial-phase amphibians and reptiles. 

2

 Freshwater fish may be surrogates for aquatic-phase amphibians. 

3

 Four species of two families of monocots; six species of at least four dicot families. 

 2.3.2. Ecosystems Potentially at Risk 

The ecosystems at risk are often extensive in scope; therefore, it may not be possible to identify 

specific ecosystems at the screening level. In general terms, terrestrial ecosystems potentially at 

risk could include the treated site and areas immediately adjacent to the treated site that may 

receive drift or runoff. These areas could include the site itself, other cultivated fields, fencerows 

and hedgerows, meadows, fallow fields or grasslands, woodlands, riparian habitats, and other 

uncultivated areas. 

Aquatic ecosystems potentially at risk include water bodies adjacent to, or down stream from, the 

treated area and might include impounded water bodies (lentic environments) such as ponds, 

lakes and reservoirs, or flowing waterways (lotic environments) such as streams or rivers. For 

uses in coastal areas, aquatic habitat also includes marine ecosystems, including estuaries. 
20

 2.4. Assessment Endpoints 

Assessment endpoints represent the actual environmental value that is to be protected, defined by 

an ecological entity (species, community, or other entity) and its attribute or characteristics 

(USEPA, 1998a). The ecological entities include the following: birds, amphibians, reptiles, 

mammals, freshwater fish and invertebrates, estuarine/marine fish and invertebrates, terrestrial 

plants, insects, and aquatic vascular and non-vascular plants. The attributes for each of these 

entities may include growth, survival, and reproduction. (See Table 2.2 in Section 2.6.2, the 

Analysis Plan, for further discussion). 

 2.5. Conceptual Model 

For a pesticide to pose an ecological risk, it must reach ecological receptors in biologically 

significant concentrations. An exposure pathway is the means by which a pesticide moves in the 

environment from a source to an ecological receptor. For an ecological pathway to be complete, 

it must have a source, a release mechanism, an environmental transport medium, and a feasible 

route of exposure. 

The conceptual model is intended to provide a written description and visual representation of 

the predicted relationships between penthiopyrad, potential routes of exposure, and the predicted 

effects for the assessment endpoints. The conceptual model consists of two major components: 

risk hypotheses and a conceptual diagram (USEPA, 1998a). 

 2.5.1. Risk Hypotheses 

For penthiopyrad, the following ecological risk hypothesis is being employed for this baselinelevel risk assessment: 

Based on the application methods, mode of action, and the sensitivity of non-target 

aquatic and terrestrial species, the proposed agricultural and non-agricultural uses of 

penthiopyrad have the potential to reduce survival, reproduction, and/or growth in 

terrestrial and aquatic animals and plants via both direct and indirect adverse effects.

 2.5.2. Conceptual Diagram 

Application methods for penthiopyrad include foliar broadcast (via ground, aerial, and 

chemigation equipment), seedling and transplant seedling treatment, and in-furrow methods. 

Ecological receptors that may potentially be exposed to penthiopyrad include terrestrial and 

semi-aquatic wildlife (i.e., mammals, birds, terrestrial-phase amphibians, terrestrial invertebrates, 

and reptiles) and plants. In addition, aquatic receptors, (i.e., freshwater and estuarine/marine fish 

and invertebrates, aquatic-phase amphibians, and plants) may also be exposed as a result of 

potential movement of penthiopyrad to aquatic environments via spray drift, runoff, and/or base 

flow from ground water leachate originating at the site of application (no direct applications to 

water bodies are proposed). The potential exposure pathways and effects of the proposed new 

registration of penthiopyrad are depicted in Figure 2.1. 
21

Stressor

Penthiopyrad applied as a broadcast spray to agricultural and nonagricultural areas

Source/

Transport

Pathways

Direct

Deposition

Spray

Drift

Runoff/

Erosion

Leaching

(Infiltration/

Percolation

Source/

Exposure

Media

Terrestrial Food 

Residues (foliage, 

fruit, insects

Upland

Foliage/Soil

Riparian/

Wetland 

Foliage/Soil

Receiving 

Water Body/ 

Sediment

Groundwater

Exposure

Route

Ingestion Direct contact/

Root Uptake

Direct contact/

Root Uptake

Gill/

Integument 

Uptake

Receptors

Attribute

Changes

Terrestrial Vertebrates

Birds, Mammals,

Reptiles, Terrestrial 

Phase Amphibians

Terrestrial

Upland

Plants

Individual Animals

Reduced survival

Reduced growth

Reduced

reproduction

Aquatic 

Invertebrates

Aquatic 

Vertebrates

Wetland/ 

Riparian

Plants

Individual Plants

Seedling emergence

Vegetative vigor

Individual 

vertebrates and 

invertebrates

Reduced

survival

Reduced

growth

Reduced

reproduction

Plant 

population

Reduced

population

growth

Aquatic 

Plants

Uptake/ 

Adsorption

Figure 2.1. Conceptual Model Depicting Sources of Exposure, Receptors, and Potential 

Adverse Effects from the Proposed Uses of Penthiopyrad.1

1

 Inhalation is a potential route of exposure to terrestrial organisms (i.e., birds, and mammals); however 

inhalation is not considered to be an exposure route of concern as indicated by Screening Tool for 

Inhalation Risk (STIR v.1.0, November 19, 2010) (see Appendix A). 

 2.6. Analysis Plan 

 2.6.1. Residues of Concern 

The major degradates of penthiopyrad (i.e., those degradates constituting greater than 10% of 

applied residues from environmental fate studies) include PAM, PCA, DM-PCA, and carbon 

dioxide (chemical names and structures are provided in Appendix B). Available toxicity data 

for the major organic degradates indicate that they are orders of magnitude less toxic than 

penthiopyrad to freshwater fish, freshwater invertebrates, and aquatic non-vascular plants. 

However, PAM is a residue of concern for mammals (including humans) due to a lack of toxicity 

data and its prevalence in animal residue studies (USEPA, 2011). 

The minor degradates 753-T-DO, 753-A-OH, and 753-F-DO, which have the same structural 

backbone as the parent, were >7% of the applied and increasing in concentration at study 

termination in some studies and may have toxicity similar to the parent compound to freshwater 
22

invertebrates and aquatic plants (toxicity endpoints for 753-A-OH and 753-T-DO were within an 

order of magnitude, although most were non-definitive). However, 753-A-OH and 753-T-DO 

were substantially less toxic than penthiopyrad to freshwater fish. 

In conclusion, the residues of concern are penthiopyrad, 753-T-DO, 753-A-OH, and 753-F-DO 

for aquatic invertebrates and aquatic plants, penthiopyrad alone for fish, and penthiopyrad and 

PAM for terrestrial organisms. 

Because 1) inclusion of 753-A-OH, 753-T-DO, and 753-F-DO in exposure modeling would not 

appreciably increase exposure estimates, and 2) major degradates of penthiopyrad are much less 

toxic to aquatic organisms than the parent compound, penthiopyrad alone was modeled to 

estimate exposure for aquatic organisms in this assessment. 

 2.6.2. Measures of Exposure 

Measures of exposure are based on terrestrial and aquatic models that estimate environmental 

concentrations of the chemical being assessed using labeled application rates and methods. The 

measure of exposure for aquatic species in water bodies receiving runoff and/or spray drift is the 

estimated environmental concentration (EEC) expected once every ten years based on 30 years 

of simulations. The 1-in-10 year peak concentration is used for estimating acute effects to 

aquatic vertebrate and invertebrate species; the 1-in-10 year 21-day mean concentration is used 

for assessing aquatic invertebrate chronic exposure; and the 1-in-10 year 60-day mean 

concentration is used for assessing chronic exposure for fish (and aquatic-phase amphibians). 

Aquatic EECs were calculated with the Tier II aquatic exposure model PRZM/EXAMS (PE) and 

with the Tier I Rice Model for use on cranberries. Tier I and II provisional flooded agriculture 

models (Tier I Cranberry Model and PFAM) were used to further characterize potential exposure 

resulting from use on cranberries. EECs from exposure to the Fontelis and Vertisan end-use 

products via spray drift were calculated using the spray drift model AgDRIFT. Exposure in 

ground water due to leaching was assessed with the Tier I screening ground water model SCIGROW. The bioaccumulation model KABAM was used to estimate potential bioaccumulation 

of penthiopyrad residues in a freshwater aquatic food web and subsequent risks these residues 

may pose to terrestrial organisms via consumption of contaminated aquatic prey (i.e., aquatic 

invertebrates and fish). The terrestrial measure of exposure for animals is upper bound exposure 

concentrations on various dietary items that are estimated with T-REX. Exposure of naturallyoccurring terrestrial and semi-aquatic (wetland) plant species is typically estimated using OPP’s 

TerrPlant (v1.2.2) model to provide estimates of exposure to terrestrial plants from single 

pesticide applications and is assumed to encompass areas outside the immediate use site. 

However, only Tier I terrestrial plant toxicity data are available, and treatment related effects 

were observed at the limit concentration in both the seedling emergence and vegetative vigor 

studies. Although effects were not greater than 25% for any endpoint that was tested, Terrplant 

is not appropriate for use in the risk assessment. The registrant has provided a suite of Office of 

Chemical Safety and Pollution Prevention (OCSPP) guideline-compliant environmental fate and 

product chemistry studies that provide data for these measures of exposure (OCSPP guidelines 

are also known as OPPTS guidelines). 
23

PE (PRZM/EXAMS) 

The Tier II model Pesticide Root Zone Model (PRZM v3.12.2; May 12, 2005; Carousel et al., 

undated) linked with EXposure Analysis Modeling System (EXAMS v2.98.4.6; Apr. 25, 2005; 

Burns, 2004) via the model shell PRZM/EXAMS (PE v5.0, Nov. 15, 2006) was run to estimate 

baseline-level exposure of aquatic environments to penthiopyrad. The PRZM model simulates 

pesticide movement and transformation on and across the agricultural field resulting from crop 

applications. The EXAMS model simulates pesticide loading via runoff, erosion, and spray drift 

assuming a “standard” 1-ha pond, 2-m deep (20,000 m3

) with no outlet that borders a 10-ha 

treated field. Simulations are run for multiple (usually 30) years, and the Agency estimates peak 

and running mean values that are expected once every ten years based on the daily values 

generated during the simulation. The PE, PRZM, and EXAMS models and users manuals are 

available from the U.S. Environmental Protection Agency Water Models web-page (USEPA, 

2011a). 

Exposure estimates generated using the “standard” pond are intended to represent those that 

might occur in a wide variety of vulnerable water bodies that occur at the top of watersheds 

including prairie pot holes, playa lakes, wetlands, vernal pools, man-made and natural ponds, and 

intermittent and first-order streams. As a group, there are factors that make these water bodies 

more or less vulnerable than the standard surrogate pond. Static water bodies that have larger 

ratios of pesticide-treated drainage area to water body volume would be expected to have higher 

peak EECs than the standard pond. These water bodies will be either smaller in size or have 

large drainage areas. Smaller water bodies have limited storage capacity and thus may overflow 

and carry pesticide in the discharge, whereas the standard pond has no discharge. As watershed 

size increases, it becomes increasingly unlikely that the entire watershed is planted with a nonmajor single crop that is all treated simultaneously with the pesticide. Headwater streams can 

also have peak concentrations higher than the standard pond, but they likely persist for only short 

periods of time and are then carried and dissipated downstream. 

Tier I Rice Model 

The Tier I Rice Model (v1.0, May 8, 2007) was used to estimate screening-level exposure to 

penthiopyrad that may occur in water bodies receiving released bog water following use on 

cranberries. This model was used to assess the proposed use on cranberries because exposure 

models specific to cranberries uses are not vetted and approved for use in risk assessment. The 

model produces a single exposure value that represents a dissolved concentration within a rice 

paddy. This single value is used to approximate both acute and chronic exposure. 

The Tier I Rice Model relies on an equilibrium partitioning concept to provide conservative 

exposure estimates resulting from application of pesticides to rice paddies. When a pesticide is 

applied to a rice paddy, the model assumes that it will instantaneously partition between a water 

phase and a sediment phase. The model does not account for pesticide degradation, mass 

transfer between the aqueous phase and the sediment, volatilization, dilution, or other dissipation 

processes. The Tier I Rice Model was calibrated to generate estimates that are consistent with or 

conservative for dissolved concentrations measured within rice paddies and in discharged paddy 

water. The model was not evaluated or calibrated for concentrations measured in sediment and 
24

does not account for residues bound to suspended sediment. Furthermore, the model was not 

calibrated to evaluate exposure in cranberry bogs. A description of and guidance for using the 

Tier I Rice Model may be found on the U.S. Environmental Protection Agency (EPA) Water 

Models web-page (USEPA, 2011a). 

Tier I Flooded Agriculture Model (Tier I Cranberry Model) 

In order to characterize exposure from the proposed use on cranberries, a provisional Tier I 

Cranberry Model was used to estimate screening-level peak and mean concentrations of 

penthiopyrad that may occur in water bodies receiving released bog water following use on 

cranberries. This model is produced by making two provisional refinements to the Tier I Rice 

Model, including the addition of simple degradation processes in dry and flooded conditions and 

a water depth of twelve inches, rather than the water depth of four inches used in the rice model. 

The cranberry bog water depth of twelve inches is a maximum depth recommended by the Cape 

Cod Cranberry Growers Association (2001). Previous assessments of mesotrione uses that 

employed the provisional Tier I Cranberry Model assumed a water depth of eighteen inches (DP 

barcode 339984, USEPA, 2004; DP barcode 325840, USEPA, 2006a), which is within the range 

of water depths traditionally used. However, modern water conservation pressures are causing 

cranberry growers to reduce the flood depth to fewer inches above the vertical cranberry 

branches, which grow up to eight inches high (Cape Cod Cranberry Growers Association, 2001; 

The Cranberry Institute, 2008). Therefore, a twelve-inch deep flood is a reasonable refinement 

to model assumptions. The equations used in the provisional Tier I Cranberry Model are briefly 

described in Appendix F. 

Degradation of penthiopyrad may be dominated by indirect photolysis on soil prior to flooding at 

harvest. However, the effect on potential aquatic exposure from indirect photolysis on soil was 

not explored due to the high exposure estimates resulting from the initial model scenario of no 

photolysis on the bog prior to flooding. A Tier II modeling approach was used next to refine 

aquatic exposure estimates. 

Tier II Flooded Agriculture Model (PFAM)

For characterization, the provisional, Tier II Pesticides in Flooded Applications Model (PFAM 

v0.7; pre-release) was run to refine aquatic exposure estimates for the proposed use of 

penthiopyrad on cranberries. PFAM simulates pesticide transformation on and dissipation from 

flooded agricultural sites, such as cranberry bogs, following pesticide use. Up to 11 applications 

and up to 11 manually controlled changes in bog water level can be modeled per year of 

simulation. Simulations were run using 30 years of location-specific rainfall data. 

A Variable Volume Water Model (VVWM) post-processor was used in conjunction with PFAM 

to produce aquatic exposure concentrations in a flowing water body that receives released 

cranberry bog water. Peak and maximum mean exposure estimates that are expected once every 

ten years in the modeled water body were generated based on daily values produced during the 

simulation. PFAM and associated documentation are available on-line at: 

http://sites.google.com/site/pfamodel/. 
25

SCI-GROW 

The Tier I model Screening Concentration in Ground Water (SCI-GROW v2.3, Jul. 29, 2003; 

USEPA, 2002b) was used to estimate screening-level exposure in aquatic environments from 

base flow of ground water containing penthiopyrad. SCI-GROW is a regression model that was 

developed by fitting a linear model to ground water concentrations with the Relative Index of 

Leaching Potential (RILP) as the independent variable. Ground water concentrations were taken 

from 90-day mean high concentrations from Prospective Ground Water studies. The RILP is a 

function of aerobic soil metabolism and the soil-water partition coefficient. The output of SCIGROW represents the concentration of pesticide residue that might be expected in shallow 

unconfined aquifers under sandy soils, which is representative of the ground water most 

vulnerable to pesticide contamination and likely to result in contaminated base flow in nearby 

surficial water bodies. This single 90-day mean value is used to approximate both acute and 

chronic exposure. The SCI-GROW model and user’s manual are available from the EPA Water 

Models web-page (USEPA, 2011a). 

AgDRIFT 

AgDRIFT (v2.01; May 24, 2001) was used to estimate aquatic exposure resulting from direct 

spray drift of Fontelis and Vertisan formulations into the “standard” 1-hectare pond. Details 

concerning the specifics and uncertainties associated with the AgDRIFT model are available 

online at www.agdrift.com. 

KABAM 

KOW (based) Aquatic BioAccumulation Model (KABAM v.1.0) was used to estimate potential 

bioaccumulation of penthiopyrad residues in a freshwater aquatic food web and subsequent risks 

these residues pose to terrestrial organisms via consumption of contaminated aquatic prey (i.e., 

aquatic invertebrates and fish). The bioaccumulation portion of KABAM is based on an aquatic 

food web bioaccumulation model published by Arnot and Gobas (2004) that relies on a 

pesticide's octanol-water partition coefficient (KOW) to estimate uptake and elimination constants 

through respiration and diet of aquatic organisms in different trophic levels. Pesticide tissue 

concentrations in aquatic organisms are calculated for different trophic levels of a food web 

through diet and respiration. 

In the risk component of KABAM, pesticide concentrations in aquatic organisms are used to 

estimate dose- and dietary-based exposures and associated risk quotients for mammals and birds 

consuming aquatic organisms. The methods used in the risk component of KABAM are 

consistent with EFED's current modeling approach for assessing risks to terrestrial mammals and 

birds described in USEPA 2004a, as implemented in the T-REX model (version 1.4.1; USEPA 

2008a). The KABAM model and user’s manual are available from the EPA Water Models webpage (USEPA, 2011a). 
26

T-REX 

T-REX is a spreadsheet-based model that calculates the residues on avian and mammalian food 

items along with the dissipation rate of a chemical applied to foliar surfaces (for single or 

multiple applications) in order to estimate acute and reproductive risk quotients. The median 

lethal dose to 50% of the animals tested (LD50) per square foot (ft-2) values are also calculated 

for both broadcast and banded (granular and liquid) applications using an adjusted LD50 method. 

The results are presented by weight class for various sized birds and mammals for each type of 

application. Avian and mammalian risk quotients are also calculated for seed treatment 

applications to various crop seeds. The T-REX model and user’s manual are available from the 

EPA Terrestrial Models web-page (USEPA, 2011b). 

 2.6.3. Measures of Effect 

Measures of effect are obtained from a suite of registrant-submitted OCSPP guideline-compliant 

studies that were conducted with a limited number of surrogate test species (Table 2.1). No 

additional ecotoxicity data on penthiopyrad were located, based on a July 2011 query of the open 

literature in the ECOTOX database (USEPA, 2011b). 

The acute measures of effect used in this baseline-level assessment are the LD50, LC50 (median 

Lethal Concentration) or EC50 (median Effects Concentration). These are measures of acute 

toxicity which result in 50% of the respective effect in tested organisms. The endpoints for 

chronic measures of exposure are the NOAEC and the NOAEL. Toxicity studies were submitted 

for freshwater fish and invertebrates, estuarine/marine fish and invertebrates, aquatic plants, 

birds, mammals, bees, and other terrestrial invertebrates. The endpoints used for risk 

characterization were derived from studies which underwent review and were classified as 

“acceptable” (conducted under guideline conditions and considered to be scientifically valid) or 

“supplemental” (conditions deviated from guidelines but the results are considered to be 

scientifically valid). 

Table 2.2 lists the measures of environmental exposure and ecological effects used to assess the 

potential risks of penthiopyrad to non-target organisms. The methods used to assess the risk are 

consistent with those outlined in the document “Overview of the Ecological Risk Assessment 

Process in the Office of Pesticide Programs” (USEPA, 2004). 
27

Table 2.2. Measures of Exposure and Effect Used in Assessing Potential Risks Associated 

with the Proposed Uses of Penthiopyrad.

Assessment Endpoint Measures of Ecological Effect1 Measures of Exposure 

Birds2

Survival Lowest acute LD50 (single oral dose test) 

and LC50 (subacute dietary test) Upper-bound residues on Reproduction food items 

and Growth 

Lowest NOAEC 

 (21-week reproduction test) 

Mammals 

Survival Lowest acute LD50 (single oral dose test)

Reproduction 

and Growth 

Lowest NOAEC 

(2-generation reproduction test) 

Aquatic Animals 

(Freshwater fish and 

invertebrates and estuarine/ 

marine invertebrates)3 

Survival Lowest tested LC50 or EC50

(acute toxicity test) 

Peak EECs4 

Survival Lowest tested LC50 or EC50

(acute toxicity test using formulations) Spray drift EECs5 

Reproduction 

and Growth 

Lowest NOAEC 

(early life-stage or full life-cycle tests) 

21-day EECs for invertebrates 

and 60-day EECs for fish4 

Aquatic plants 

(vascular and non-vascular) 

Survival and 

growth 

Lowest EC25 (for non-listed plants) and 

corresponding NOAEC or EC05 

(for listed plants)

Peak EECs4

1 The most sensitive species tested within taxonomic groups is used for baseline-level risk assessments. 2 Birds represent surrogates for terrestrial-phase amphibians and reptiles. 

3 Freshwater fish represent surrogates for aquatic-phase amphibians. 4 Aquatic EECs are based on the modeling described in Section 3.2.2.1. 5

 Spray drift EECs are based on the modeling described in Section 3.2.2.1

 2.6.4. Integration of Exposure and Effects 

The exposure and toxicity effects data are integrated in order to evaluate the risks of adverse 

ecological effects on non-target species. For the risk assessment of penthiopyrad, the risk 

quotient (RQ) method is used to compare estimated exposure and measured toxicity values. The 

RQ method involves dividing EECs by acute and chronic toxicity values. The resulting RQs are 

then compared to the Agency’s Levels of Concern (LOC) (USEPA, 2004) (Table 2.3). These 

criteria are used to indicate when applications of penthiopyrad, as directed on the label, have the 

potential to cause adverse effects to listed and non-listed non-target organisms. 

Table 2.3. Agency Risk Quotient (RQ) Metrics and Levels of Concern (LOC) Per Risk 

Class.

RISK CLASS RISK DESCRIPTION RQ LOC 

Aquatic Animals (fish and invertebrates)

Acute Potential for effects to non-listed animals from acute 

exposures 

Peak EEC/LC501

 0.5 

Acute 

Restricted Use 

Potential for effects to animals from acute exposures 

Risks may be mitigated through restricted use classification Peak EEC/LC501

 0.1 

Acute Listed 

Species 

Listed species may be potentially affected by acute 

exposures 

Peak EEC/LC501

 0.05 

Chronic Potential for effects to non-listed and listed animals from 

chronic exposures 

60-day EEC/NOAEC 

(fish) 1 
28

RISK CLASS RISK DESCRIPTION RQ LOC 

21-day EEC/NOAEC 

(invertebrates) 

Aquatic Plants 

Non-Listed Potential for effects to non-listed plants from exposures Peak EEC/LC501 1 

Listed Potential for effects to listed plants from exposures Peak EEC/NOAEC 1 

Terrestrial Animals (mammals and birds) 

Acute Potential for effects to non-listed animals from acute 

exposures 

EEC2

/LC50 (Dietary) 0.5 

EEC/LD50 (Dose) 

Acute 

Restricted Use 

Potential for effects to animals from acute exposures 

Risks may be mitigated through restricted use classification

EEC2

/LC50 (Dietary) 0.2 

EEC/LD50 (Dose) 

Acute Listed 

Species 

Listed species may be potentially affected by acute 

exposures 

EEC2

/LC50 (Dietary) 0.1 

EEC/LD50 (Dose) 

Chronic Potential for effects to non-listed and listed animals from 

chronic exposures EEC2

/NOAEC 1 

1 LC50 or EC50. 2

 Based on upper bound Kenega values for foliar exposure. 

3. Analysis 

 3.1. Use Characterization 

Penthiopyrad is proposed for foliar use on alfalfa, brassica vegetables, bulb vegetables, canola, 

cereals (excluding rice and wild rice), cotton, cucurbits, fruiting vegetables, leafy vegetables, low 

growing berries (including cranberries), peanuts, pome fruits, root and tuber vegetables and 

leaves, stone fruits, succulent and dry legumes, sunflowers, tree nuts (including pistachios and 

excluding pecans), turf (including sod farms and any landscaped areas) and landscape 

ornamentals. Four end use formulations of penthiopyrad are proposed for registration in the 

United States. These include Fontelis (20% active ingredient (a.i.)), a suspension concentrate 

(SC) for a range of agricultural uses; Vertisan (20% a.i.), an emulsifiable concentrate (EC) for a 

range of agricultural uses; Treoris (8.9% a.i.), a suspension concentrate (SC) containing the 

fungicide chlorothalonil (22.3% ) and for a range of agricultural uses; and Velista (50% a.i.), a 

water dispersible granule (WG) product for use on turf and landscape ornamentals. Each 

formulation is flowable. Table 3.1 lists the proposed maximum use patterns on the proposed 

labels for these four end use formulations. 

The proposed maximum single and annual application rates for penthiopyrad are 0.95 and 2.9 

pounds of active ingredient per acre (lbs a.i./A), respectively, on turf (Velista), which 

characterizes the maximum use pattern of penthiopyrad for this national-level, ecological risk 

assessment. Fontelis, Vertisan, and Treoris each have proposed maximum single and annual 

application rates of 0.39 and 0.94 lbs a.i./A, respectively for selected agricultural uses. All uses 

are limited to two sequential applications with additional applications allowed following use of a 

fungicide with a different mode of action, with the exceptions that use on peanuts is limited to 

three sequential applications before rotating to an alternative fungicide and uses on landscape 

plantings and trees do not require rotation with alternative fungicides. 
29

Table 3.1. Proposed Use Patterns for Penthiopyrad End-use Products.

Product 

Label 

Active 

Ingredient 

(%) 

Use 

Max. Single 

App. Rate 

(lbs a.i./A) 

Max. Annual 

App. Rate 

(lbs a.i./A) 

App. 

Interval 

(d) 

Application Type Additional A

Fontelis Penthiopyrad (20%) 

Alfalfa 0.31 0.63 

7 

Aerial, ground or 

chemigation 

Make no more thapplications befofungicide with a 

Bulb vegetables; low 

growing berries A; 

fruiting vegetables 

0.31 0.94 

Leafy vegetables 

Aerial, ground, 

chemigation, seedling, 

transplant seedling or 

in-furrow 

Brassica vegetables 

0.39 0.94 

Aerial, ground, 

chemigation or seedling

Legumes (succulent)

Aerial, ground, 

chemigation, transplant 

seedling or in-furrow 

Cucurbit vegetables 0.21 0.87 5 Aerial, ground or chemigation 

Peanuts 0.31 0.94 14 

Aerial, ground, 

chemigation, transplant 

seedling or in-furrow 

Make no more thapplications befofungicide with a 

Pome fruits; stone 

fruits; tree nuts B 0.26 0.79 7 Aerial, ground or chemigation Make no more th

applications befofungicide with a 

Root vegetables and leaves 0.39 0.79 

Vertisan Penthiopyrad (20%) 

Canola 0.26 0.53 

7 

Aerial, ground or 

chemigation 

Make no more thapplications befofungicide with a 

Cereal grains C 0.31 0.63 

Cotton; root 

vegetables and leaves 0.31 0.94 

Aerial, ground, 

chemigation, transplant 

seedling or in-furrow 

Legume vegetables D 0.26 0.53 

Soybeans 

Sugarbeets 0.39 0.79 

Sunflowers 
30

Product 

Label 

Active 

Ingredient 

(%) 

Use 

Max. Single 

App. Rate 

(lbs a.i./A) 

Max. Annual 

App. Rate 

(lbs a.i./A) 

App. 

Interval 

(d) 

Application Type Additional A

Treoris 

Penthiopyrad 

(8.9%) and 

chlorothalonil 

(22.3%) 

Beans (dry) E 0.26 0.52 

7 

Aerial, ground or 

chemigation 

Make no more thapplications befofungicide with a 

Snap beans; brassica 

vegetables 0.39 

0.93 

Blueberries (lowbush)

0.31 

Aerial or ground 

Bulb vegetables; 

celery; fruiting 

vegetables; potatoes; 

yams 

Aerial, ground or 

chemigation 

Carrots; parsnips; 

soybeans 0.39 0.78 

Cucurbits 0.21 0.88 5 

Peanuts 

0.31 0.93 

14 

Make no more thapplications befofungicide with a 

Rhubarb 

7 

Ground Make no more th

applications befofungicide with a 

Cherries, peaches, 

plums; almonds, 

filberts, pistachios 

0.26 0.78 Aerial or ground 

Velista Penthiopyrad (50%) 

Turf 0.95 2.9 14 F (not stated) 

Make no more thapplications befofungicide with a 

Landscape 

ornamentals 0.25 3.0 7 Ground 

Not for use on bin commercial nuor on ornamentause or commerci

A Low growing berry uses on the Fontelis label include cranberries. B Labeled tree nut uses include pistachios and exclude pecans. C Labeled cereal grain uses include varieties of barley, buckwheat, corn, millet, oats, rye, sorghum, teosinte, triticale and wheat and exD Labeled legume vegetable uses include dry shelled peas and beans other than soybeans. E Labeled bean uses include varieties of dry beans, excluding soybeans. F The application interval of 14 days separates two fall applications. A third application may be made in the spring. 
31

 3.2. Exposure Characterization 

3.2.1. Environmental Fate and Transport Characterization 

Penthiopyrad [(RS)-N-[2-(1,3-dimethylbutyl)-3-thienyl]-1-methyl-3-(trifluoromethyl)-pyrazole4-carboxamide; CAS# 183675-82-3] is a racemic mixture of enantiomers that undergo slight 

enantiomeric selectivity (ranging from 2.6% to the R-isomer to 23% to the S-isomer) in studied 

soils (see Appendix B for chemical structure). The compound is nonvolatile, lipophilic, and 

moderately mobile in soil (Table 3.2). Indirect photolysis in soil is the fastest route of 

penthiopyrad degradation (half-life of 6.4 days); however, the compound persists in many 

compartments of the environment, dissipating in shaded and aquatic areas by slow aerobic 

biodegradation (half-life of 60-406 days) and slow leaching (KFOC range of 560-900 L/kgOC). 

Penthiopyrad does not undergo hydrolysis or photolysis in water bodies. The compound persists 

in anaerobic conditions. 

Depending on soil type, the compound may slowly move to ground water via leaching and may 

move to surface water bodies via spray drift, runoff of dissolved or sorbed residues, and transport 

of dissolved residues in base flow from shallow ground water. Terrestrial field dissipation study 

results are relatively consistent with those of the laboratory studies, showing that the chemical 

dissipates by degradation and slow leaching, with dissipation half-lives ranging from 2.2 to 44 

days (laboratory study half-lives ranged from 6.2 to >365 days). 

Penthiopyrad has an octanol-water partition coefficient (KOW) at pH 7 of 42,000; however, the 

bioconcentration data suggest that the compound is not expected to bioaccumulate in fish, mainly 

due to metabolism. Penthiopyrad may bioconcentrate in benthic invertebrates. Table 3.2

summarizes the submitted chemical and environmental fate data for penthiopyrad. 

Table 3.2. Chemical Properties and Environmental Fate Parameters of Penthiopyrad. 

Parameter Value Source

Selected Physical/Chemical Parameters 

Molecular mass (molecular formula) 359.42 g/mol (C16H20F3N3OS) (Calculated) 

Vapor pressure 2.2 x 10-8 torr (20 °C) 

4.8 x 10-8 torr (25 °C) 

MRID 47614820 

MRID 47614817 

Aqueous solubility (20C) pH 4: 2.5 mg/L pH 5: 7.5 mg/L 

pH 7: 1.4 mg/L pH 10: 1.7 mg/L 

MRID 47614828, 

47614829 

Henry’s Law Constant (20°C, pH 7) 7.6 x10-9 atm-m3/mol (Calculated) 

Log octanol-to-water partition coefficient 

(log KOW) (20°C) 

pH 4: 4.36 

pH 7: 4.62 

pH 10: 4.54 

MRID 47614832 

Dissociation constant (pKa) 10.0 MRID 47614840, 

47614841 
32

Parameter Value Source

Persistence

Hydrolysis half-life (50C) No substantial degradation 

(pH 4, 7, and 9) 

MRID 47614837 

Aqueous photolysis half-life (25C) No substantial degradation MRID 47614839 

Soil photolysis half-life; dark-control 

adjusted half-life (23C) 

6.2 d; 6.4 d MRID 47614965 

Aerobic soil metabolism half-life (20°C) 60, 81, 165, 406 d MRID 47614959 

152 d MRID 47614961 

128 d (25°C) MRID 47614963 

Anaerobic soil metabolism half-life (20C) No substantial degradation MRID 47614964 

Anaerobic aquatic metabolism half-life 

(20C) 

No substantial degradation MRID 47614976 

Aerobic aquatic metabolism half-life (20C) 220, 311 d MRID 47614975 

Aerobic activated sludge biodegradation % No substantial degradation MRID 47614974 

Mobility

Freundlich soil-water partition coefficients 

(KF); Freundlich organic carbon-normalized 

partition coefficients (KFOC) 

7.3, 9.2, 14, 14, 15 L/kg; 

560, 570, 730, 850, 900 L/kgOC

MRID 47614967 

Field Dissipation 

Terrestrial field dissipation half-life; 

maximum leaching depth of parent 

35 d (CA bare soil); 5-15 cm MRID 47615162 

4.4 d (GA bare soil); 5-15 cm MRID 47615163 

2.2 d (MO bare soil/soybeans); 0-5 cm MRID 47615164 

11 d (WA bare soil/wheat); 0-5 cm MRID 47615165 

7.9 d (Ontario bare soil); 0-5 cm MRID 47615166 

21 d (Saskatchewan bare soil); 5-15 cm MRID 47615167 

44 d (NY turf); 15-30 cm MRID 47615172 

15 d (GA turf); 15-30 cm MRID 47615173 

Fish Bioconcentration 

Fish bioconcentration factors (steady-state) 78-100 L/kg (edible); 226-277 L/kg 

(inedible); 155-184 L/kg (whole fish); 

substantial metabolism and rapid 

depuration (half-life of <1 d) were 

observed. 

MRID 47614995 

3.2.1.1. Transport and Mobility 

Penthiopyrad is not expected to significantly volatilize from soil or water bodies due to a low 

vapor pressure (2.2 x 10-8 torr at 20°C; MRID 47614820) and Henry’s Law Constant (7.6 x10-9
33

atm-m3

/mol; calculated from MRID 47614820 and 47614828). Penthiopyrad is moderately 

soluble in water (limit of 1.4-7.5 mg/L at 20°C) at environmentally relevant pH values (MRID 

47614828, -29). The compound is lipophilic, with a KOW of 23,000-42,000 (log KOW of 4.36-

4.62; MRID 47614832). With a dissociation constant (pKa) of 10 (MRID 47614840), 

penthiopyrad does not exhibit acid/base behavior in the environment. The source of the 

variability in measured aqueous solubility limits and KOW values is not understood. 

Penthiopyrad is moderately mobile in soil, with KFOC values ranging from 560-900 L/kgOC (mean 

KFOC of 720 L/kgOC; MRID 47614967). Sorption to soil correlates with the organic carbon 

fraction in soil (i.e., the coefficient of variation across five soils for KFOC (22%) is less than that 

for KF (29%). Depending on soil type, the compound may slowly move to ground water via 

leaching (e.g., in field studies, leaching ranged from <5 to >15 cm; MRID 47615162, -63, -64, -

65, -66, -67, -72, -73). Penthiopyrad may be sorbed to residues in or dissolved in runoff feeding 

surface water bodies. The compound may also reach surface water bodies via transport of 

dissolved residues in base flow from shallow ground water. 

3.2.1.2. Degradation 

Indirect photolysis in soil is the fastest route of penthiopyrad degradation (half-life of 6.2 days; 

MRID 47614965); however, the compound persists in many compartments of the environment, 

degrading in shaded and aquatic areas by slow aerobic biodegradation (half-life of 60-406 days; 

MRID 47614959, -61, -63, -75). Penthiopyrad does not undergo hydrolysis (MRID 47614837) 

or photolysis (MRID 47614839) in water bodies. The compound persists in anaerobic conditions 

(MRID 47614976) and is not readily biodegraded in aerobic activated sludge (MRID 47614974). 

Penthiopyrad is assumed to undergo indirect photolysis in soil because it degraded in irradiated 

soil and was stable to direct photolysis in water. This means that the compound is not directly 

photolyzed by light. Instead, it is susceptible to degradation in the presence of light-absorbing 

organic molecules in soil, such as humic and fulvic acids (i.e., indirect photolysis). The total 

degradation half-life in soil was 6.2 days. Adjusted for biodegradation in the dark controls, the 

photolysis-only half-life was 6.4 days. Major degradates included PAM (up to 48% of the 

applied radioactivity (%AR) at study termination), PCA (up to 41%AR 13 days after treatment), 

and carbon dioxide (up to 26-52%AR at study termination; chemical names and structures are 

listed in Appendix B). In the study, unradiolabled test compound was mixed with pyrazole- and 

thienyl-radiolabeled test compound prior to treating the test samples, resulting in uncertainty in 

amounts of transformation products formed. The applicant indicated that the radiolabeled test 

compounds were applied at equivalent doses (MRID 48239607). Therefore, measured amounts 

of single-ring degradates reported in the study were multiplied by two by the reviewers in order 

to indicate the amounts that would have been measured in a study of penthiopyrad with a single 

radiolabel (e.g., PAM at 24%AR was interpreted as at 48%AR). Also, measured amounts of 

carbon dioxide and unextracted residues were reported as ranges from 1x to 2x the measured 

value because the actual value in a single radiolabeled study would lie somewhere in that range 

(e.g., carbon dioxide reported at 26%AR was interpreted as 26-52%AR). 
34

Penthiopyrad slowly degraded in six aerobic soils with half-lives ranging from 60 to 406 days 

(MRID 47614959, -61, -63). The major degradates in these studies included DM-PCA (up to 

28%AR at study termination) and carbon dioxide (up to 26%AR at study termination). 

Extraction procedures were not considered exhaustive; unextracted residues were up to 40%AR. 

Studies of two soils were terminated before the first DT50 of the compound had passed, which 

results in uncertainty in the degradation kinetics of penthiopyrad and in the formation and 

degradation kinetics of penthiopyrad’s transformation products. For example, the compound 

753-T-DO was 8.1%AR and increasing at study termination (161 days after treatment). It is 

unclear whether 753-T-DO would have been a major degradate if the study was continued. 

In aerobic aquatic systems, penthiopyrad persisted with degradation half-lives of 220 and 311 

days (MRID 47614975). These half-lives were extrapolated because the studies were terminated 

at 185 days after treatment, which was before the first DT50 of the test compound had passed. 

The only major transformation product was PCA (up to 12%AR at 111 days after treatment; 

9.3%AR at 185 days after treatment). Carbon dioxide was only formed at up to 8.8%AR. 

In anaerobic soil and aquatic systems, penthiopyrad did not degrade (MRID 47614964, -76). 

Penthiopyrad photolysis in soil and aerobic biodegradation in soil and water appears to follow 

two main pathways (see Figure B.1 of Appendix B): 1) oxidation at the carbon atom adjacent to 

the sulfur atom of the thienyl ring, leading to 753-T-DO followed by further oxidation to 753-FDO, and 2) hydroxylation at the alkyl side chain, leading to OH-substituted products such as 

753-A-OH (chemical names and structures are provided in Table B.1 of Appendix B). The 

degradates 753-F-DO and 753-A-OH do not accumulate but undergo further oxidation, leading 

to PAM and to transient sister cleavage products. PAM is then transformed to PCA by amide 

hydrolysis. PCA undergoes N-demethylation of the pyrazole ring to form DM-PCA. Ultimately, 

the pyrazole ring degradates are mineralized, as carbon dioxide is the major degradation product 

of DM-PCA (MRID 47614966). The environmental fate of the trifluorinated methyl group is 

unknown. 

3.2.1.3. Bioaccumulation 

While penthiopyrad is lipophilic, with a KOW of 23,000-42,000 (log KOW of 4.36-4.62; MRID 

47614832), it is not expected to bioaccumulate in fish. Bioconcentration factor (BCF) values in 

fish were ≤277 L/kg and the compound was readily metabolized in fish to an assortment of 

minor metabolites (MRID 47614995). Penthiopyrad accounted for only 35-42% of total 

radioactivity in fish after 10-14 days of accumulation. The compound depurated with a half-life 

of 0.65-0.86 days; however, depuration rates decreased over time since measured BCF values for 

whole fish remained 10-25 L/kg in both systems after 3-14 days of depuration. Respective 

depuration rate constants (kT of 0.81-1.07) were well above the sum of elimination constants 

estimated by KABAM (k2+kE+kG of 0.23), which supports the study finding that the compound 

was readily metabolized in fish (KABAM neglects metabolism by default). 

Steady-state fish BCF value ranges reported in this assessment include study-reported values as 

well as calculated values that are 18% higher in order to correct for the potential loss of 
35

bioavailable residues due to sorption to total organic carbon (TOC) in the test systems. TOC was 

up to 52 mg C/L due to the cosolvent, dimethylformamide (DMF), and, to a minor extent, 

organic carbon present in the untreated water (up to 6 mg C/L). An equation from Arnot and 

Gobas (2004) describing the fraction of test compound dissolved in water (in Table A.2 of the 

KABAM User’s Guide) indicated that up to 15% of the test compound may have bound to TOC, 

resulting in fish BCF values that may have been underestimated by 15%. 

Bioconcentration of penthiopyrad in benthic invertebrates is uncertain and of concern. Studyderived metabolism rates in fish cannot be extrapolated to metabolism rates in benthic 

invertebrates since the latter often metabolize compounds slower than fish. KABAM modeling 

(that assumes that benthic invertebrates do not metabolize penthiopyrad) indicates that 

bioconcentration of penthiopyrad in benthic invertebrates results in chronic risk LOC 

exceedances for mammals that consume benthic invertebrates (see Section 4.2.2.2). LOCs were 

not exceeded for mammals that do not consume benthic invertebrates. Oyster BCF study data 

could be used to reduce uncertainty in the bioaccumulation of penthiopyrad in benthic 

invertebrates. 

3.2.1.4. Field Studies 

Six terrestrial field dissipation studies were initiated on bare soil under field conditions in the 

United States and Canada (CN) in 2006 using penthiopyrad formulated as a suspension 

concentrate (200 g/L SC) containing 200 g a.i./L (MRID 47615162, -63, -64, -65, -66, -67). Two 

additional cropped plots were prepared at sites in Washington and Missouri. The study authors 

expected a low degradation rate and that the presence of a crop would accelerate chemical 

dissipation in the field; however, initial soil sample analysis showed a fast dissipation of 

penthiopyrad in cropped and bare soil. Therefore, analysis of soil samples from cropped plots 

was terminated early, with crop samples not analyzed. For the California, Georgia, Ontario 

(CN), and Saskatchewan (CN) sites, two broadcast applications of the test substance were 

applied to the test plots at the target rate of 400 g a.i./ha (0.357 lbs a.i./A) at an interval of 15 

days. A single broadcast application of the test substance was applied to the test plots at the 

target rate of 200 g a.i./ha (0.178 lbs a.i./A) for Washington and 100 g a.i./ha (0.089 lbs a.i./A) 

for the Missouri site. Soil samples were taken up to a depth of 90 cm and composited by depth 

at intervals over approximately 18 months at the test sites. 

Penthiopyrad degraded at all sites to form several degradates. The major degradates were DMPCA, PAM, and PCA. Degradates 753-A-OH, 753-F-DO and 753-T-DO were also detected at 

lower levels. The recovery of applied penthiopyrad using Petri dishes on the soil surface was 

between 75 and 107%, being between 75 and 87% for most sites. Therefore, the detected 

amounts of degradates may have been slightly underestimated. 

Penthiopyrad dissipated in bare soil fields with half-lives ranging from 2.2 to 35 days (half-lives 

were partially correlated with soil pH; r2

 = 0.74). By the study end, <5% unchanged parent 

remained at all bare soil sites and <10 % was present at the cropped sites, indicating that there is 

little potential for further primary degradate formation after the end of the study. The majority of 

residues were measured in the top 30 cm of soil, with no residues detected below 70 cm depth 
36

and no penthiopyrad detected below 15 cm. The main degradation products formed during the 

early sampling period (Day 14, 15, and 21) were PCA, PAM, and 753-F-DO, which were the 

main photolytic products in the soil photolysis study (MRID 47614965), suggesting that 

photochemical oxidation contributed to the early dissipation of penthiopyrad. Both 

penthiopyrad and its degradates tended to remain on the soil surface for up to 100 days, with 

little being incorporated into the lower depths, so that residues may be exposed to sunlight. 

Dissipation rates were relatively consistent with the laboratory data, if the range of dissipation 

rates reflected the range of insolation received on the fields. 

Terrestrial field dissipation studies were conducted on turf-covered fields located in Georgia and 

New York in 2007 using penthiopyrad formulated as a suspension concentrate (SC) containing 

200 g a.i./L. At the Georgia site, the test substance was applied as two broadcast applications at 

the target rate of 750 g a.i./ha each, with a 14-day interval, for a total of 1500 g a.i./ha. At the 

New York site, the test substance was applied as three broadcast applications at the target rate of 

500 g a.i./ha (0.446 lbs a.i./A) each, with a 14-day interval, for a total of 1500 g a.i./ha (1.34 lbs 

a.i./A). 

Turf, thatch, and soil samples were taken at intervals over approximately 195 days in Georgia 

and 208 days in New York following test substance application. At both sites, penthiopyrad 

partitioned from the turf into the thatch and soil layers. Residues of penthiopyrad in the soil 

were mostly confined to the uppermost thatch layer, and <1% of the applied material was found 

in the 15-30 cm layer. There were no significant detections in the lower soil depths, below 30 

cm. There were no detectable residues of any of the degradation products below 15 cm at any 

point, except for DM-PCA that was detected at 30-50 cm depth in Georgia and 50-70 cm depth 

in New York. Penthiopyrad degraded at both sites to form several degradates. The main 

degradate was DM-PCA. Also detected were the degradates PAM, PCA, 753-A-OH, 753-F-DO, 

and 753-T-DO. 

Penthiopyrad dissipated in the turf fields with half-lives of 15 days in Georgia and 44 days in 

New York. By comparison to the half-life in the Georgia turf field study, in 2006, penthiopyrad 

dissipated in the bare soil field dissipation study conducted in Georgia with a half-life of 4.4 days 

(MRID 47615163). This 10-fold difference in dissipation may be explained by suppression of 

indirect photolysis of penthiopyrad on the field due to the presence of turf. 

3.2.1.5. Environmental Degradates 

Major identified environmental degradates of penthiopyrad are PAM, PCA, DM-PCA, and 

carbon dioxide. Available chemical names and structures are listed in Table B.1 of Appendix B

as well as maximum and final amounts formed in the submitted studies. Figure B.1 of 

Appendix B illustrates the transformation pathway of penthiopyrad in the environment. 

Penthiopyrad’s major organic degradates are cleavage products that retain the pyrazole ring of 

the parent compound. PAM is the only degradate that retains the amide group of penthiopyrad. 

The degradates PAM, PCA, and DM-PCA were persistent in studies of penthiopyrad. PAM and 

DM-PCA increased in concentration throughout the studies in which they were major degradates 
37

(soil photolysis and aerobic soil metabolism studies, respectively); whereas PCA concentrations 

reached a plateau and began to slowly decline in the soil photolysis and aerobic aquatic 

metabolism studies in which it was a major degradate. A submitted study indicates that DM-PCA 

degrades in aerobic soil with a mean half-life of 109 days (n=4; range 36-168 days; MRID 

47614966). 

The major organic degradates of penthiopyrad are highly mobile in soil. Mean KFOC values for 

PAM, PCA, and DM-PCA are 9.1, 8.1, and 7.0 L/kgOC (n=4; MRID 47614971, -69, and -66). 

Table 3.3 lists the available environmental fate parameters of penthiopyrad’s degradates. 

Table 3.3. Environmental Fate Parameters of Penthiopyrad Transformation Products.

Parameter Test Compound Value Source

Persistence

Aerobic soil metabolism half-life 

(20°C) 

DM-PCA 36, 110, 121, 168 d MRID 47614966

Mobility

Freundlich soil-water partition 

coefficients (KF); Freundlich 

organic carbon-normalized 

coefficients (KFOC) 

DM-PCA 0.033, 0.061, 0.094, 0.099 L/kg; 

3, 4, 5, 16 L/kgOC

MRID 47614966

PAM 0.1, 0.4, 0.4, 0.4 L/kg; 

6.5, 8.7, 9.0, 12 L/kgOC

MRID 47614971

753-A-OH 2.0, 2.1, 2.2, 3.0 L/kg; 

45, 54, 63, 210 L/kgOC

MRID 47614972

753-T-DO 5.0, 16, 23, 26 L/kg; 

460, 460, 500, 510 L/kgOC

MRID 47614973

The submitted environmental fate studies of penthiopyrad did not directly show formation of 

hydrofluorocarbons or opening of the pyrazole ring to which the trifluorinated methyl group is 

attached. However, the pyrazole ring was indirectly shown to have cleaved due to the formation 

of carbon dioxide with the pyrazole-radiolabel. Formation of hydrofluorocarbons could not be 

observed because the test compound was not radiolabeled on or near the trifluorinated methyl 

group. Also, most of the study lengths were not sufficient to evaluate the fate of the residues 

containing the pyrazole ring because the parent compound was slow to degrade. This leads to 

uncertainty in the formation of hydrofluorocarbons. 

Trifluoroacetic acid (CAS 76-05-1) may be a major transformation product of penthiopyrad. It is 

a degradation product shared by many pesticides with a trifluorinated methyl group (e.g., 

saflufenacil, benfluralin, trifloxystrobin, fluometuron, and thiafluamide/flufenacet), 

hydrochlorofluorocarbons (HCFC), and hydrofluorocarbons (HFC). According to the Hazardous 

Substances Data Bank, with a vapor pressure of 110 torr at 25°C, trifluoroacetic acid will 

volatilize and not persist if released to the air or dry soil (USNIH, 2009). However, if formed in 

water bodies or wet soil, trifluoroacetic acid is a persistent anion (pKa of 0.52) that will not 

degrade by abiotic or microbial means. The compound has been detected in surface water, 

seawater, and precipitation (USNIH, 2009). 
38

The available aquatic toxicity data for trifluoroacetic acid show low toxicity for fish and aquatic 

invertebrates (LC/EC50 >1200 mg/l) and a range of algal species (NOEC values are above 100 

mg/L, with one exception (Scenedesmus capricornutum) at 0.12 mg/L; Europian Union, 2001). 

Also, continuous exposure (>5 months) to trifluoroacetic acid at 31-32 mg/L may cause 

adaptation in the physiology of stream bacterial communities (Europian Union, 2001). Based on 

these data, there is low aquatic toxicity concern for trifluoroacetic acid and, therefore, risk 

concern is presumed low. Thus, the ecological risk from trifluoroacetic acid is not quantitatively 

estimated in this assessment. 

Trifluoroacetic acid may slowly decarboxylate to the greenhouse gas fluoroform (HFC-23, 

CHF3, CAS 75-46-7) with a half-life of approximately 80 years (Boutonnet et al., 1999; Wine, 

1994). Fluoroform (with a global warming potential of 12,000; USEPA, 2011c) persists in air 

with a lifetime of 222 years and will gradually diffuse into the stratosphere, in which its lifetime 

is 2,300 years (UNEP, 2010). However, data are not sufficient to indicate whether penthiopyrad 

residues will ultimately form fluoroform. If they do, formation of fluoroform would not be 

observed in guideline-compliant laboratory studies, with a formation half-life of approximately 

80 years, and it may be too early to observe a signal in available monitoring data from pesticides 

with trifluoromethyl groups that were registered in the last few decades. If penthiopyrad 

degrades to fluoroform, the amount produced is likely to be negligible with respect to industrial 

sources of the compound (UNEP, 2010). On a broader level, it is unclear how much total usage 

of pesticides with trifluoromethyl groups would be of concern with respect to other sources of 

fluoroform, if these pesticides ultimately degrade to fluoroform. 

3.2.2. Measures of Aquatic Exposure 

Exposure in surface water from the proposed penthiopyrad uses due to runoff, erosion, and spray 

drift were assessed with the Tier II screening model, PE, and, to assess the proposed use on 

cranberries, the Tier I Rice Model. Provisional Tier I and Tier II (PFAM) flooded agriculture 

models were also used to characterize exposure from the proposed use on cranberries. Exposure 

in ground water due to leaching was assessed with the Tier I screening ground water model SCIGROW.

3.2.2.1. Surface Water Exposure 

PE (PRZM/EXAMS) 

The general chemical and environmental fate data for penthiopyrad listed in Table 3.2 were used 

for generating model input parameters for PE (listed in Table 3.4). These inputs represent 

penthiopyrad alone, since addition of degradates of concern would not appreciably change 

exposure estimates (see Section 2.6.1), and were determined in accordance with current 

divisional guidance (USEPA, 2009). The 90% confidence bounds on the mean half-life for 

aerobic soil metabolism (240 d) and for aerobic aquatic metabolism (287 d) were selected. Halflives from the submitted aerobic aquatic metabolism study conducted at 20°C were adjusted 

using a Q10 of 2 to those that would occur at 25°C, which PE requires. 
39

Table 3.4. PE Chemical Input Parameters for Penthiopyrad. 

Input Parameter Value Comment Source (MRID)

Molecular Mass (g/mol) 359.4 Product chemistry data (Calculated) 

Henry’s Law Constant 

(atm-m3/mol) 

7.6 x 10-9 Product chemistry data (Calculated) 

Solubility in Water (mg/L) 1.4 Represents the value at pH 7. 47614828 

Organic Carbon Partition 

Coefficient (KOC) (L/kgOC) 

720 Represents the mean KfOC of five values. 47614967 

Aerobic Soil Metabolism 

Half-life (days) 

240 Represents the upper 90% confidence bound on 

the mean of six half-lives. 

47614959, -61, 

-63 

Aerobic Aquatic Metabolism 

Half-life (days) 

287 Represents the upper 90% confidence bound on 

the mean of two half-lives adjusted to 25°C. 

47614975 

Anaerobic Aquatic 

Metabolism Half-life (days) 

0 Represents no biodegradation under anaerobic 

conditions. 

47614976 

Hydrolysis Half-life (days) 0 Represents no hydrolysis. 47614837 

Aqueous Photolysis 

Half-life (days) 

0 Represents no photolysis. 47614839 

Laboratory and field studies indicate that penthiopyrad may photolyze extensively on the field 

(with a half-life of 6.2 days over 29 days of natural sunlight; MRID 47614965). Because soil 

photolysis is an important route of degradation in some environments, PE was also used to 

bracket potential aquatic exposure (for characterization) using a soil photolysis input in place of 

the aerobic soil metabolism input. A soil photolysis input of 19 days was used for the aerobic 

soil metabolism input because it is 3x the single study value of 6.2 days (MRID 47614965). Use 

of the aerobic soil metabolism input of 240 days represents the case of no photolysis on the field; 

use of the soil photolysis input of 19 days represents the case of photolysis on the field, at the 

rate observed in a laboratory study, prior to transportation into water bodies. The case that is 

most relevant for a given location depends on the extent to which penthiopyrad is indirectly 

photolyzed at the location based on 1) the amount of shade available on the field, 2) the 

availability and composition of photo-oxidizers in the soil, and 3) the duration between 

applications and following runoff events. 

The model input parameters used in PRZM to simulate penthiopyrad application and crop 

management practices are provided in Table 3.5. Modeled use patterns represent the highest 

labeled single application rates, the maximum numbers of applications per year in order to apply 

the maximum annual application rate, the shortest re-application intervals, and the labeled 

application method of greatest spray drift for each use group listed in Table 3.1. 

Model scenarios and initial application dates were selected in order to represent the high-end of 

vulnerability. Specifically, each model scenario that is representative for a given use was 

modeled using a range of initial application dates limited to the 1st and 15th day of each month 

within the cropping period, based on labeled crop timing for applications, crop timing set by the 

model scenario, and crop-profile information provided by the United States Department of 

Agriculture (USDA, 2011). For example, use on sorghum was preliminarily modeled with the 

Kansas and Texas sorghum scenarios with initial application dates ranging from June 1st to 

August 15th. The combination of scenario and intial application date that resulted in the highest 
40

estimated environmental concentrations (EEC) was selected for this assessment and listed in 

Table 3.5 below. The North Dakota corn scenario was used as a surrogate scenario for 

sunflowers because a scenario specific to sunflowers is not available, the majority of sunflowers 

are grown in North Dakota (USDA), 2011), and corn is most similar to sunflower with respect to 

the crops represented by available North Dakota scenarios. 

Most proposed uses of penthiopyrad have a minimum reapplication interval of 7 days between 

two applications and most have the stipulation that no more than two sequential applications may 

be made before switching to a fungicide with a different mode of action. Therefore, a 14-day 

interval was assumed between the second and third applications for most proposed uses with 

three applications allowed at the maximum rate per year. Proposed uses with alternative label 

directions, including turf, peanuts, and cucurbits, were modeled accordingly. 

Table 3.5. PRZM Scenario and Input Parameters Describing the Maximum Proposed 

Penthiopyrad Use Patterns. 

Use Scenario

Date of 

Initial 

App. 

App. Rate 

(lbs a.i./A)

App. 

per 

Year

App. 

Interval 

(days) 

CAM 

Input

IPSCND 

Input 

Application 

Efficiency/ 

Spray Drift

Turf A CA turf Mar. 1st 0.95 3 245, 14 B 2 3 0.99/0.01 

Landscape ornamentals CA residential Apr. 1st 0.25 12 7 2 3 0.99/0.01 

Brassica STX vegetable Feb. 21st 0.39, 0.15 C 3 7, 14 C 2 1 0.95/0.05 

Succulent legumes MS soybean Sep. 15th 0.39, 0.15 C 3 7, 14 C 2 1 0.95/0.05 

Peanuts NC peanuts Aug. 29th 0.31 3 14 2 1 0.95/0.05 

Cucurbits STX melons Apr. 1st 0.21 4 5, 10 D 2 1 0.95/0.05 

Alfalfa NC alfalfa Jul. 15th 0.31 3 7, 14 C 2 1 0.95/0.05 

Berries FL strawberries Jan. 15th 0.31 3 7, 14 C 2 1 0.95/0.05 

Bulb vegetables STX vegetable Feb. 21st 0.31 3 7, 14 C 2 1 0.95/0.05 

Fruiting vegetables FL peppers Nov. 1st 0.31 3 7, 14 C 2 1 0.95/0.05 

Leafy vegetables CA lettuce Apr. 15th 0.31 3 7, 14 C 2 1 0.95/0.05 

Pome fruits PA apple Jun. 1st 0.26 3 7, 14 C 2 3 0.95/0.05 

Root vegetables FL carrots Nov. 1st 0.39 2 7 2 1 0.95/0.05 

Stone fruit MI cherries Jun. 15th 0.26 3 7, 14 C 2 3 0.95/0.05 

Tree nuts OR filberts Oct. 1st 0.26 3 7, 14 C 2 3 0.95/0.05 

Dry beans IL beans Jul. 15th 0.26 2 7 2 1 0.95/0.05 

Potatoes and yams FL potato Mar. 1st 0.31 3 7, 14 C 2 1 0.95/0.05 

Cotton MS cotton Aug. 1st 0.31 3 7, 14 C 2 1 0.95/0.05 

Sugarbeets MN sugarbeets Aug. 1st 0.39 2 7 2 1 0.95/0.05 

Sunflowers ND corn Jun. 15th 0.39 2 7 2 1 0.95/0.05 

Canola ND canola Jun. 1st 0.26 2 7 2 1 0.95/0.05 

Sorghum (cereals) KS sorghum Aug. 15th 0.31 2 7 2 1 0.95/0.05 

Wheat (cereals) TX wheat Apr. 1st 0.31 2 7 2 1 0.95/0.05 
41

Use Scenario

Date of 

Initial 

App. 

App. Rate 

(lbs a.i./A)

App. 

per 

Year

App. 

Interval 

(days) 

CAM 

Input

IPSCND 

Input 

Application 

Efficiency/ 

Spray Drift

Corn (cereals) TX corn Jul. 15th 0.31 2 7 2 1 0.95/0.05 

A The use on turf includes sod farms and any landscape areas. 

B The second application occurs on Nov. 1st, 245 days after the initial application. The third application follows on 

Nov. 15th, 14 days later (PE cannot split a set of multiple applications across years). 

C Two applications at 0.39 lbs a.i./A, 7 days apart, are followed 14 days later by an application at 0.15 lbs a.i./A. 

D Two applications 5 days apart followed after 10 days by two additional applications 5 days apart. 

Aquatic EECs from PE for the proposed penthiopyrad uses are presented in Table 3.6. The 

model input/output files supporting these values are listed and provided in Appendix C. These 

exposure estimates are intended to be protective for this screening-level assessment. They 

represent the most vulnerable model scenario and timing for uses and use groups listed in Table 

3.1. Therefore, exposure estimates in United States locations not modeled or from application 

timing not modeled may be less than those listed in Table 3.6. Also, where use patterns were 

modeled to represent use groups, uses in the group that were not individually modeled may result 

in lower exposure than the use selected to represent the group. Modeled EECs represent aquatic 

exposure that may occur from a use or use within a group at a particular time and location in the 

United States. 

The 1-in-10-year peak values ranged from 13 μg/L (canola) to 45 μg/L (succulent legumes). 

Rolling mean values were similar to peak values due to the persistence of penthiopyrad. The 1-

in-10-year 21-day pore water EEC for succulent legumes that is used to assess exposure to 

benthic invertebrates is 38 μg/L. Although proposed uses on turf and landscape ornamentals 

have higher application rates than other proposed uses, exposure estimates for uses on turf and 

ornamentals were less than those for many proposed agricultural uses because aerial application 

to turf and ornamentals is not allowed, whereas aerial application is allowed for most proposed 

agricultural uses. 

The persistence of penthiopyrad also resulted in carry-over of residues from year to year, leading 

to an increase of maximum values over the first 15-20 years of the simulation until equilibrium 

in the standard pond was attained (see Figure 3.1). Therefore, exposure estimates are not true 1-

in-10-year values. Because exposure estimates for the proposed uses of penthiopyrad did not 

widely vary, the EECs for the uses of highest (legumes) and lowest (canola) exposure were used 

for risk estimation in this screening-level assessment. 
42

Figure 3.1. EECs for Succulent Legumes from 1961 to 1990. 

Table 3.6. PE 1-in-10-year Aquatic EECs for Proposed Penthiopyrad Uses.

Use Scenario Max. App. Rate 

(lbs a.i./A/yr) Peak (μg/L) 21-day (μg/L) 60-day (μg/L)

Succulent legumes MS soybean 0.94 45 44 41 

Fruiting vegetables FL peppers 0.94 45 43 40 

Cucurbits STX melons 0.87 43 41 39 

Cotton MS cotton 0.94 42 40 39 

Potatoes and yams FL potato 0.93 42 40 39 

Alfalfa NC alfalfa 0.63 40 38 37 

Corn (cereals) TX corn 0.63 40 37 36 

Brassica STX vegetable 0.94 38 36 34 

Bulb vegetables STX vegetable 0.94 38 36 33 

Root vegetables FL carrots 0.79 37 35 32 

Leafy vegetables CA lettuce 0.94 35 34 33 

Berries FL strawberries 0.94 34 33 33 

Peanuts NC peanuts 0.94 34 32 30 

Pome fruits PA apple 0.79 31 30 28 

Wheat (cereals) TX wheat 0.63 29 28 26 

Dry beans IL beans 0.52 27 26 26 

Sorghum (cereals) KS sorghum 0.63 26 25 24 

Turf CA turf 2.9 25 25 25 

Sunflowers ND corn 0.79 24 23 23 

Stone fruit MI cherries 0.79 23 23 23 

Tree nuts OR filberts 0.79 23 22 22 

Landscape ornamentals CA residential 3.0 21 20 20 

Sugarbeets MN sugarbeets 0.79 21 20 20 

Canola ND canola 0.53 13 13 12 

0

10

20

30

40

50

60

1955 1960 1965 1970 1975 1980 1985 1990 1995

EEC (μg/L)

Year

Succulent legume EECs

Peak

96 hr

21 Day

60 Day

90 Day

Yearly
43

Exposure estimates for use on legumes on the initial year of application, prior to annual 

accumulation in the standard pond, were 17 μg/L (peak), 16 μg/L (21-day mean), and 13 μg/L 

(60-day mean). For canola, exposure estimates from the initial year of application were 1.4 μg/L 

(peak), 1.2 μg/L (21-day mean), and 0.99 μg/L (60-day mean), which is substantially less than 

accumulates in the model pond over multiple years.

If unabetted photolysis is assumed to occur on the field (using a soil photolysis input of 19 days 

rather than the aerobic soil metabolism input of 240 days), 1-in-10-year exposure estimates for 

use on legumes are reduced by 40-43% to 27 μg/L (peak), 25 μg/L (21-day mean), and 24 μg/L 

(60-day mean). For canola, 1-in-10-year exposure estimates are reduced by 38-40% to 8.1 μg/L 

(peak), 7.8 μg/L (21-day mean), and 7.4 μg/L (60-day mean).

Tier I Rice Model 

The Tier I Rice Model has two inputs: the application rate and the organic carbon partition 

coefficient (KOC). The maximum proposed single application rate of penthiopyrad on cranberries 

(0.31 lbs a.i./A or 0.35 kg a.i./ha) was modeled as well as the annual application rate limit (0.94 

lbs a.i./A or 1.05 kg a.i./ha). The mean KFOC value for five soils (720 L/kgOC) was input as well. 

The exposure estimates from the Tier I Rice Model for quantitative exposure assessment of the 

proposed use on cranberries were 176 μg/L (single use) and 529 μg/L (annual use). The single 

exposure estimates from the Tier I Rice Model are used for both acute and chronic exposure 

assessment. Additional provisional models were used to characterize exposure from the 

proposed use on cranberries because the screening exposure estimate from the Tier I Rice Model 

(529 μg/L) was an order of magnitude higher than screening exposure estimates from PE. 

Tier I Cranberry Model (Provisional) 

The proposed use of penthiopyrad on cranberries at the maximum proposed application rate 

(0.31 lbs a.i./A) may occur no more than three times per year, based on the annual application 

rate limit (0.94 lbs a.i./A). The minimum reapplication interval is 7 days between two 

applications, with the stipulation that no more than two sequential applications may be made 

before switching to a fungicide with a different mode of action. Therefore, a 14-day interval was 

assumed between the second and third applications. There is no proposed pre-harvest interval. 

Cranberry bogs are not typically flooded until the night before harvesting. Therefore, the 

proposed single application rate (0.31 lbs a.i./A) was aged on dry soil with the Provisional 

Cranberry Model for three durations: 21, 14, and 0 days. The resulting residues (in lbs a.i./A) 

were summed together for each residue and input into the flooded component of the model to 

estimate exposure in bog tailwater following harvest. Peak and annual mean exposure estimates 

were calculated beginning three days after flooding to account for the holding time during 

harvest. Chemical property input values were the same as those calculated for PE modeling. 

Model input parameters are listed in Table 3.7. 
44

Table 3.7. Provisional Cranberry Model Input Parameters for Penthiopyrad.A

Input Parameter Value Comments Source

Application Rate 

(lbs a.i./A) 0.31 Maximum proposed single application rate. Proposed label 

Applications per Year 3 

Maximum proposed number of 

applications per year at the maximum 

proposed single application rate. 

Proposed label 

Application intervals (d) 0, 14, 21 

Discussion of intervals between 

applications and prior to harvest is 

provided in text above. 

Proposed label 

Organic Carbon Partition 

Coefficient (KOC) (L/kgOC) 720 Represents the mean KFOC value for five soils. MRID 47614967 

Aerobic Soil Metabolism 

Half-life (days) 240 Represents the upper 90% confidence 

bound on the mean of six half-lives. 

MRID 47614959, 

47614961, 

47614963 

Aerobic aquatic 

metabolism 

half-life (days) 

287 

Represents the upper 90% confidence 

bound on the mean of two half-lives 

adjusted to 25°C. 

MRID 47614975 

A Source data are in Tables 3.1 and 3.4. 

Exposure estimates from the provisional Tier I Cranberry Model for use on cranberries were 250 

μg/L (peak), 245 μg/L (21-day mean), and 233 μg/L (60-day mean). These values were 

sufficiently high to trigger the need for additional refinement. 

PFAM (Provisional)

Model input parameters for PFAM and its associated VVWM post-processor are listed in Table 

3.8. Chemical-specific inputs represent the residues of concern, which include penthiopyrad 

alone (see Section 2.2.1), and were determined in accordance with current divisional guidance 

for PRZM and EXAMS (USEPA, 2009). The 90% confidence bounds on the mean half-life for 

aerobic soil metabolism (240 d) and for aerobic aquatic metabolism (406 d) were selected 

(PFAM automatically corrects the aerobic aquatic metabolism half-life for temperature; 

therefore, the input value differs from the temperature-corrected value used in other aquatic 

models). The heat of Henry (i.e., enthalpy of solvation; 55,000 J/mol) was calculated by 

multiplying the gas constant (8.314 J/mol·K) by the enthalpy of vaporization for penthiopyrad 

(6,600 K) estimated by HenryWin (v3.20). 

Table 3.8. PFAM Input Parameters for Penthiopyrad.

Input Parameter Value Comments Source

Water column half-life (d) at 

20 °C 406 Represents the upper 90% confidence 

bound on the mean of two half-lives. MRID 47614975 

Benthic Compartment half-life at 

20 °C (d) 0 Represents no biodegradation under 

anaerobic conditions. MRID 47614976 

Unflooded half-life at 20 °C (d) 240 Represents the upper 90% confidence 

bound on the mean of six half-lives. 

MRID 47614959, 

-61, -63 
45

Input Parameter Value Comments Source

Aqueous photolysis half-life at 

40° Latitude (d) 0 Represents no photolysis in water. MRID 47614839 

Hydrolysis half-life (d) 0 Represents no hydrolysis. MRID 47614837 

Organic Carbon Partition 

Coefficient (KOC) (L/kgOC) 720 Represents the mean KFOC value for five soils. MRID 47614967 

Molecular weight (g/mol) 359.4 Product chemistry data (Calculated) 

Vapor pressure at 20 °C (torr) 2.2 x 10-8 Product chemistry data MRID 47614820 

Water solubility at 20 °C (mg/L) 1.4 Product chemistry data MRID 47614828 

Heat of Henry at 20 °C (J/mol) 55,000 

Equals 8.314 × enthalpy of salvation 

(6,600 K) estimated by HenryWin 

v3.20. 

(Calculated) 

Application Date & Rate 

(kg a.i./ha) 

9/9: 0.348 

9/16: 0.348 

9/30: 0.348 

Maximum proposed single application 

rate. Minimum intervals between 

applications and flooding. 

Proposed label 

Meteorology data location 

(metfile code) 

La Crosse, WI 

(w14920) 

Meteorological file for a location near 

cranberry agriculture. CEAM, 2011 

Fill level (m); Wier level (m) 10/1: 0.305; 0.458 

10/2: 0; 0 

Minimum flood depth and release 

depth; estimated wier heights (Estimated) 

Crop zero height reference May 1 Estimated value (Estimated) 

Days from zero to full height 120 Estimated value (Estimated) 

Days from zero height to removal 153 Estimated value (Estimated) 

Max. aerial coverage 0.2 Value from OR berries PE scenario (Estimated) 

Area of application (m2) 526,090 Represents 10x the area of the Index 

Reservoir (Calculated) 

Area of watershed (m2) 1,728,000 Area of the Index Reservoir watershed USEPA, 2010a

Watershed curve number 84 Value for fallow conditions in OR 

berries and other PE scenarios (Estimated) 

The application dates were chosen to represent the minimum intervals allowed between 

applications and between the final application and harvest (flooding). The modeled 

meteorological data were collected from 1961 to 1990 in La Crosse, Wisconsin, which is the 

location closest to the majority of cranberry agriculture for which meteorological data were 

collected by the EPA Center for Exposure Assessment Modeling (CEAM, 2011). A 12-inch 

flood was modeled on October 1, followed by draining the following day and throughout the 

year. The modeled flood date was selected as a plausible date of harvest. Alternative flood dates 

were explored and not used because they produced similar results. Crop stages were estimated. 

The maximum aerial coverage for berry crops used in the OR berries scenario for PE was used in 

PFAM as well. 

The VVWM was used to collect water and pesticide residues released from the modeled 

cranberry bog. The Index Reservoir parameters of the model were used rather than those for 

EFED’s standard farm pond because the Index Reservoir has flow, whereas the standard pond 

does not, and cranberry bogs release into flowing water bodies. In order to maintain the 10:1 

ratio of the treatment area to water body that is used for ecological aquatic exposure modeling, 

the treatment area (526,090 m2

) was set to 10x that of the Index Reservoir (52,090 m2). The area 

of the watershed that contains the Index Reservoir was kept at the standard value of 1,728,000 
46

m

2

. The curve number used for the watershed (84) was set to that for fallow conditions often 

used in PE scenarios, such as the OR berries scenario. 

Exposure estimates from PFAM with its associated VVWM post-processor were 298 μg/L 

(peak), 293 μg/L (21-day mean), and 289 μg/L (60-day mean). These values are 19-24% higher 

than EECs from the provisional Tier I Cranberry Model and roughly 2x less than the EEC from 

the Tier I Rice Model. Although these values are high, no other models are available with 

which to estimate exposure from use on cranberries. Aquatic exposure estimates from the 

provisional Tier I and Tier II flooded agriculture models are uncertain because the models have 

not been thoroughly vetted and evaluated with monitoring data. Due to the uncertainty in the 

provisional models, the results from both (i.e., the Tier I Cranberry Model and PFAM) were used 

to characterize aquatic exposure from use on cranberries. 

Spray Drift of End-Use Products

The Tier I Aerial mode of AgDrift was used to estimate aquatic exposure resulting from direct 

spray drift of Fontelis and Vertisan formulations into the “standard” 1-hectare pond (i.e., the 

“EPA-Defined Pond” in the “Aquatic Assessment” tool in the AgDRIFT Toolbox. The pond 

was assumed to be at the edge of the treatment area. The default drop size distribution of ASAE 

fine to medium was input as well as the two highest single application rates proposed for Fontelis 

and Vertisan (0.39 and 0.31 lbs a.i./A). The resulting EECs were 2.77 μg/L (from 0.39 lbs 

a.i./A) and 2.20 μg/L (from 0.31 lbs a.i./A). 

3.2.2.2. Ground Water Exposure 

Input parameters for the SCI-GROW model appear in Table 3.9. These inputs were determined 

in accordance with current divisional guidance (USEPA, 2009). The median organic carbon 

partition coefficient (KOC = 730 L/kgOC) and the median half-life (140 d) from six aerobic soils 

were selected (aerobic soil metabolism half-lives range 6.8-fold). 

Table 3.9. SCI-GROW Input Parameters for Penthiopyrad. Source data are in Tables 3.1-

3.2.

Input Parameter Value Comments Source

Application Rate 

(lbs a.i./A) 0.95 Maximum proposed single application rate. Proposed label. 

Applications per Year 3 

Maximum proposed number of applications per 

year at the maximum proposed single 

application rate. 

Proposed label. 

Organic Carbon Partition 

Coefficient (KOC) (L/kgOC) 730 Represents the median of five KfOC values. MRID 47614967 

Aerobic Soil Metabolism 

Half-life (days) 140 Represents the median half-life in six soils. 

MRID 47614959, 

47614961, 

47614963 

The modeled ground water EEC resulting from penthiopyrad use on turf was 0.49 μg/L. 

Because this value is substantially less than surface water EECs and the lowest endpoint for 
47

aquatic organisms, it was not used for risk estimation. The model input/output file supporting 

this exposure estimate is provided in Appendix C. 

3.2.2.3. Aquatic Bioaccumulation 

KABAM was used to estimate potential bioaccumulation of penthiopyrad residues in a 

freshwater aquatic food web and subsequent risks these residues pose to terrestrial organisms via 

consumption of contaminated aquatic prey (i.e., aquatic invertebrates and fish). 

Estimated BCF Values 

In order to estimate BCF values for aquatic organisms accumulating penthiopyrad, KABAM was 

run using a log KOW of 4.62 (MRID 47614832) to represent the partitioning of penthiopyrad to 

aquatic organisms. It was assumed that the small fish lipid content was 7.27% and the water 

temperature was 12.9 o

C (reflecting a mean for two systems), which reflect values measured in 

the submitted fish BCF study (MRID 47614995). The body characteristics of organisms in the 

model trophic levels are depicted in Table 3.10. The resulting BCF values for these trophic 

levels are depicted in Table 3.11. Output files from KABAM are provided in Appendix C. 

Table 3.10. Characteristics of model aquatic organisms used to derive BCF values. 

Trophic Level 

Wet Weight 

(kg) 

% 

lipids 

% Non-lipid 

organic matter % Water 

phytoplankton N/A 2.0% 8.0% 90.0% 

zooplankton 1.0E-07 3.0% 12.0% 85.0% 

benthic invertebrates 1.0E-04 3.0% 21.0% 76.0% 

filter feeders 1.0E-03 2.0% 13.0% 85.0% 

small fish 1.0E-02 7.3% 23.0% 69.7% 

medium fish 1.0E-01 4.0% 23.0% 73.0% 

large fish 1.0E+00 4.0% 23.0% 73.0% 

Table 3.11. Estimated BCF values for penthiopyrad in aquatic organisms. 

Trophic Level Total BCF 

(μg/kg-ww)/(μg/L) 

Phytoplankton 2002 

Zooplankton 1427 

Benthic Invertebrates 1546 

Filter Feeders 1016 

Small Fish 3368 

Medium Fish 2004 

Large Fish 2004 

Empirical BCF data 

The highest fish BCF value for fish viscera in the submitted fish BCF study performed with 

rainbow trout (Oncorhynchus mykiss) was 277 (MRID 47614995). Substantial metabolism 

(confirmed by the presense of metabolites) and rapid depuration were observed. Due to high 
48

total organic carbon (TOC) concentrations in the test systems, study-reported fish BCF values 

may be 15% lower than actual values (see Section 3.2.1.1 for discussion); therefore, fish BCF 

values used in this assessment (e.g., 277) include calculated values that are 18% higher than 

reported values in order to correct for the potential sorption of residues to TOC in the test 

systems and the resulting potential reduction of bioavailable residues dissolved in water. 

Bioaccumulation modeling 

KABAM was run in default mode (see user’s guide for full description), with a log KOW of 4.62, 

a KOC of 720 L/kgOC (MRID 47614967) and surface water and pore water EECs of 45.0 and 38.1 

μg/L, respectively. These PE-generated surface and pore water EECs are based on the 1-in-10-

year 4-day mean concentrations of penthiopyrad from use on succulent legumes. These EECs 

were selected because they represent the highest 4-day mean EECs predicted for any use of 

penthiopyrad (penthiopyrad appeared to reach steady state in the submitted fish BCF study in 

less than 4 days) and result in the highest predicted accumulation of penthiopyrad in tissues of 

aquatic organisms. The average water temperature (12.9 o

C) of the test systems and the fish lipid 

content of 7.27% in the submitted fish BCF study were used to simulate the water temperature of 

the abiotic compartment of KABAM and fish lipid content of small fish in KABAM, 

respectively. Metabolism rate constants (kM) of 0.58 or 0.84 were input for small, medium, and 

large fish in order to account for the rapid metabolism observed in the submitted fish BCF study. 

The metabolism rate constant inputs were calculated with Equation H.4 of the KABAM User’s 

Manual [kM = kT - k2 - kE - kG, i.e., the metabolism rate constant (kM) = the total elimination rate 

constant (kT) – the respiratory elimination rate constant (k2) – the excretion elimination rate 

constant (kE) – the organism growth rate constant (kG)] using each of the two total elimination 

rate constants (kT) from the submitted study and KABAM-calculated values for the elimination 

and growth rate constants (k2, kE, and kG). The resulting exposure estimates of penthiopyrad in 

mammals and birds ingesting fish contaminated by the compound (based on the kM of 0.58) are 

provided in Table 3.12. Output files from KABAM are provided in Appendix C. These values 

were used to derive RQs based on dose-based or dietary-based exposures of birds, terrestrial 

phase amphibians, reptiles, and mammals to penthiopyrad through consumption of contaminated 

aquatic prey (see Section 4.2.2). 

Table 3.12. Concentrations of penthiopyrad residues in mammals and birds ingesting 

contaminated fish (estimated using KABAM). 

Wildlife species Dose Based (mg/kg-bw/d) Dietary Based (ppm) 

Mammalian 

fog/water shrew 42 71 

rice rat/star-nosed mole 25 55 

small mink 6.7 23 

large mink 5.2 23 

small river otter 4.4 23 

large river otter 1.8 11 

Avian 

sandpipers 54 55 

cranes 6.3 47 

rails 32 59 
49

Wildlife species Dose Based (mg/kg-bw/d) Dietary Based (ppm) 

herons 7.4 47 

small osprey 4.6 23 

white pelican 1.2 11 

3.2.3. Measures of Terrestrial Exposure 

The application methods for the proposed penthiopyrad uses include aerial, ground, chemigation, 

transplant seedling, or in furrow applications, and are considered in the terrestrial exposure 

assessment. 

3.2.3.1. Terrestrial Wildlife 

Terrestrial wildlife exposure estimates are typically calculated for birds and mammals, 

emphasizing a dietary exposure route for uptake of pesticide active ingredients. Exposures for 

birds are considered as surrogates for terrestrial-phase amphibians as well as reptiles. For 

exposure to terrestrial organisms, such as birds and mammals, pesticide residues on food items 

are estimated, based on the assumption that organisms are exposed to pesticide residues in a 

given exposure use pattern. 

The T-REX model (v1.4.1; 10/9/08) is used to calculate dietary and dose-based EECs of 

penthiopyrad residues on food items via spray applications for mammals and birds. Input values 

for deriving EECs in T-REX are located in Table 3.13. Upper-bound Kenaga nomogram values 

are used to derive EECs for penthiopyrad exposures to terrestrial mammals and birds. Table 

3.14 summarizes the dietary- and dose-based EECs, based on the maximum single application 

rate of penthiopyrad is for the proposed turf use which results in the highest EECs for all use 

scenarios. Remaining proposed uses on agricultural crops result in lower maximum single 

application rates; therefore, the EECs for both the maximum and minimum single application 

rate for the agricultural proposed uses of penthiopyrad were also calculated and are summarized 

in Table 3.14. A 1-year time period is simulated. Consideration is given to different types of 

feeding strategies for mammals, including herbivores, insectivores and granivores. For dosebased exposures, three weight classes of birds (20, 100, and 1000 g) and three weight classes of 

mammals (15, 35, and 1000 g) are considered. Uncertainties in the terrestrial EECs are primarily 

associated with a lack of data on interception and subsequent dissipation from foliar surfaces. 

Given that no data on interception and subsequent dissipation from foliar surfaces are available 

for penthiopyrad, a default foliar dissipation half-life of 35 days is used based on the work of 

Willis and McDowell (1987). Uncertainties can also be attributed to using TREX to model 

potential systemic residues. Penthiopyrad is subject to xylem systemicity, and the movement 

within the plant is not necessarily known, residues could be greater or less depending on the 

location and movement of the compound within the plant. An example output from the T-REX 

model is provided in Appendix D. 
50

Table 3.13. T-REX Input Parameters for Deriving Terrestrial EECs for Penthiopyrad 

Proposed Uses - Maximum single application rate1

Proposed Use 

(Formulation; Application Method) 

Application Rate 

(lbs a.i./A) 

Number of Applications 

(Interval between applications)* 

Non-agricultural (Turf) 

(Velista; flowable application) 0.95 2 (14 days) 

Agricultural (maximum) 

(Fontelis, Vertisan, and Treoris; aerial, 

ground or chemigation) 

0.39 2 (14 days) 

Agricultural (minimum) 

(Fontelis, and Treoris; aerial, ground or 

chemigation) 

0.21 2 (14 days) 

1 Half-life used was the default 35 days, the body weight of chronic mammals was adjusted to 135g (body weight of 

test organisms during the study, MRID 47614906 and 47614907). 

* No more than 2 sequential applications are allowed, before switching fungicides; annual maximum allows 

additional applications after switching fungicides. For the proposed turf use, the application interval separates two 

fall applications. A third application may be made in the spring. The only use that does not specify the number of 

sequential applications is the landscape ornamental use under the Velista label. 

Table 3.14. T-REX Calculated EECs of Penthiopyrad Proposed Uses 

Proposed Uses 

(Application 

Rate; lbs a.i./A) 

Food Type

Dietary 

Based 

(ppm) 

(mammals 

and birds)

Dose Based 

(mg/kg-bw) 

(birds)

Dose Based 

(mg/kg-bw) 

(mammals)

All Size 

Classes 

Small 

(20 g) 

Medium

(100 g) 

Large 

(1000 g)

Small 

(15 g) 

Medium

(35 g) 

Large 

(1000 g)

Non-Agricultural 

use 

(Turf ; 0.95 lbs 

a.i./A) 

Short grass 401 456 260 117 382 264 61.2 

Tall grass 184 209 119 53.4 175 121 28.1 

Broadleaf 

plants/sm 

insects 

225 257 146 65.6 215 149 34.4 

Fruits/pods/lg 

insects 25.0 28.5 16.3 7.28 23.9 16.5 3.83 

Seeds 

(granivore) N/A 6.34 3.62 1.62 5.31 3.67 0.85 

Maximum 

Agriculture use 

(i.e., Brassica 

vegetables, 

legumes, 

soybeans, 

sugarbeets, 

sunflowers, 

carrots, parsnip, 

snap beans; 0.39 

lbs a.i./A) 

Short grass 175 199 114 50.9 167 115 26.8 

Tall grass 80.3 91.4 52.1 23.3 76.5 52.9 12.3 

Broadleaf 

plants/sm 

insects 

98.5 112 64.0 28.6 93.9 64.9 15.1 

Fruits/pods/lg 

insects 10.9 12.5 7.11 3.18 10.4 7.21 1.67 

Seeds 

(granivore) N/A 2.77 1.58 0.71 2.32 1.60 0.37 
51

Proposed Uses 

(Application 

Rate; lbs a.i./A) 

Food Type

Dietary 

Based 

(ppm) 

(mammals 

and birds)

Dose Based 

(mg/kg-bw) 

(birds)

Dose Based 

(mg/kg-bw) 

(mammals)

All Size 

Classes 

Small 

(20 g) 

Medium

(100 g) 

Large 

(1000 g)

Small 

(15 g) 

Medium

(35 g) 

Large 

(1000 g)

Minimum 

Agriculture use 

(cucurbits; 0.21 

lbs a.i./A) 

Short grass 96.1 109 62.4 27.9 91.6 63.3 14.7 

Tall grass 44.0 50.1 28.6 12.8 42.0 29.0 6.73 

Broadleaf 

plants/sm 

insects 

54.0 61.5 35.1 15.7 51.5 35.6 8.25 

Fruits/pods/lg 

insects 6.00 6.84 3.90 1.75 5.72 3.96 0.92 

Seeds 

(granivore) N/A 1.52 0.87 0.39 1.27 0.88 0.20 

3.3. Ecological Effects Characterization 

The ecological effects characterization is based on registrant-submitted toxicity data for 

penthiopyrad (also referred to as MTF-753, technical grade active ingredient (TGAI), or 

technical parent product); three of its formulated products, including Fontelis (DPX-LEM17 

20SC; 20.4% penthiopyrad), Vertisan (DPX-LEM17 20EC; 20.6% penthiopyrad), and Treoris 

(DPX-QFA61 SC; 8.9% penthiopyrad and 22.3% chlorothalonil); and the metabolites of 

penthiopyrad (DM-PCA, PCA, PAM, 753-A-OH, and 753-T-DO). Appendix H lists these 

studies, their review classifications, and associated deficiencies. 

In addition, the publicly-available version of the ECOTOX database was searched on July 29, 

2011 in order to provide more ecological effects data (USEPA, 2011b). The results of this query 

show that no additional ecotoxicity data are available for penthiopyrad or its degradates; 

therefore, all toxicity endpoints are taken from registrant-submitted studies. 

A description of available aquatic and terrestrial toxicity data for penthiopyrad, its formulated 

products, and degradates is provided in Section 3.3.1 and 3.3.2, respectively. 

Given that penthiopyrad is a new active ingredient with no previous registration in the U.S. or 

any other country, a query of the Agency’s Office of Pesticide Programs Ecological Incident 

Information System (EIIS) was not completed, and it is assumed that no ecological incidents 

exist for penthiopyrad. The Treoris formulated product is co-formulated with chlorothalonil (PC 

code 081901) a currently registered active ingredient. A query of the EIIS database found 33 

incidents with potential links to chlorothalonil use as of June 17, 2007 (no new incidents were 

identified as of September 13, 2011). Incidents recorded in the EIIS database are ranked 

according to level of certainty with which the incident can be linked with chemical exposure. 
52

For more detailed information on the incidents related to chlorothalonil, see the 2007 CRLF risk 

assessment4

. 

3.3.1. Aquatic Toxicity Characterization 

A summary of the most sensitive aquatic toxicity data for penthiopyrad, including its formulated 

products, Fontelis, Vertisan, and Treoris, based on a current Agency review of all submitted data, 

is provided in Table 3.15 and discussed further in Sections 3.3.2.1 through 3.3.2.5. No 

ecotoxicity data was submitted for either the Velista (WDG) or WG formulations of 

penthiopyrad, which is an uncertainty as the Fontelis and Vertisan formulations will not be 

typical end-use products (TEP) for the Velista or WG formulations. For the formulations with 

associated ecotoxicity data, the Fontelis and Vertisan formulations were relatively similar in 

toxicity as the TGAI, with one exceptions; the Fontelis formulation was more toxic than the 

TGAI to daphnids. The Treoris formulated product, which is co-formulated with chlorothalonil, 

is more toxic than the penthiopyrad TGAI. The available acute aquatic toxicity data for the 

Treoris formulated product is 28 to 137 times more toxic than the technical grade penthiopyrad 

to freshwater fish, invertebrates, and aquatic non-vascular plants. However, it was determined 

that this difference in toxicity was due to the presence of the co-formulated chlorothalonil active 

ingredient, and is not a synergistic effect of the combination of penthiopyrad plus chlorothalonil 

co-formulation. When the available toxicity data for the chlorothalonil active ingredient are 

compared to the toxicity results from the co-formulation, the aquatic toxicity endpoints for fish, 

invertebrates, and plants are similar to those for chlorothalonil alone (Appendix F). Therefore, 

risk was assessed for the active ingredient and formulation products that contain penthiopyrad 

alone as the active ingredient, and not the co-formulation. Risk due to exposure to chlorothalonil 

was evaluated in a separate assessment (USEPA, 2010)5

. The available aquatic toxicity data 

show that the DM-PCA, PCA, PAM, 753-A-OH, and 753-T-DO metabolites are less toxic to 

aquatic animals and plants than the parent penthiopyrad (Appendix E). Therefore, acute toxicity 

endpoints for the parent penthiopyrad, including the Fontelis, and Vertisan formulations in terms 

of the penthiopyrad active ingredient are used in the risk assessment for freshwater aquatic 

animals and plants, where available. 

It should be noted that several toxicity endpoints for aquatic test species exceed the limit of 

penthiopyrad’s solubility in water (1.4 mg/L at pH of 7). This can be attributed to the use of a 

solvent (dimethylformamide (DMF)) in the test solutions of several studies. Data were not used 

in the risk assessment if a precipitate was present in the study and test concentrations were not 

centrifuged or mixed. Therefore, although several toxicity endpoints are above penthiopyrad’s 

solubility, EFED has confidence in the toxicity values that are being used to estimate risk 

quotients because precipitates were not observed in those studies and test concentrations were 

measured. 

 

4 http://www.epa.gov/espp/litstatus/effects/redleg-frog/#chlorothalonil.

5

 US EPA. 2010. Ecological Assessment for the IR-4 Registration of Chlorothalonil (Bravo Weather Stik®/Bravo®

720, 54%; EPA Reg. 50534-188) and the Degradation Product, 4-Hydroxy-2,5,6-trichloro-1,3-dicyanobenzene 

(SDS-3701) for the New Uses On: Blub Vegetables, Bushberris, and Low Growing Berries. (PC Code: 081901; DP 

Barcode: 370488) (Decision: 419169). Dated August 2, 2010. 
53

Table 3.15. Summary of the Most Sensitive Acute and Chronic Toxicity Data for Aquatic 

Organisms Exposed to Penthiopyrad 

Aquatic Animals 

Species Test 

Substance 

Acute Toxicity Chronic Toxicity 

96-hr LC50/EC50

(μg a.i./L) 

(Toxicity 

Classification) 

48-hr EC50

(mg a.i./L) 

(Toxicity 

Classification)

 MRID 

NOAEC/ 

LOAEC 

(μg a.i./L) 

(Endpoints) 

 MRID 

Fathead 

minnow 

(Pimephales 

promelas) 

TGAI 

98.6% 

290 μg a.i./L 

(Highly toxic) -- 47614988 

100/188 

μg a.i./L 

 (Growth: total 

length & dry 

weight) 

 47614994

Sheepshead 

Minnow 

(Cyprinodon 

variegates)

TGAI 

98.6% 

1381 μg a.i./L 

(Moderately 

toxic) 

-- 47615034 476.2/897 

μg a.i./L* 

Calculated 

using an 

ACR of 

2.91

Waterflea 

(Daphnia 

magna)

TGAI 

98.6% -- 

2531 μg a.i./L 

(Moderately 

toxic) 

47614996 

471/818 

μg a.i./L 

(Reproduction) 

47615003 

Waterflea 

(Daphnia 

magna)

Fontelis 

20% a.i. -- 

59.6 μg a.i./L 

(Very highly 

toxic) 

47615226 

10.61/20.75 

μg a.i./L 

(Survival, 

Reproduction, 

length) 

47615236 

Eastern oyster 

(Crassostrea 

virginica)

TGAI 

98.6% 

1200 μg a.i./L 

(Moderately 

toxic) 

-- 47615033 223/388 

μg a.i./L* 

Calculated 

using 

ACR of 

5.372

Aquatic Plants 

Species Test 

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

Marine Diatom 

Skeletonema 

costatum 

TGAI 

98.6% 

96 hr EC50 =1200 μg a.i./L 

NOAEC =417 μg a.i./L 

Cell density 

 (47615006) 

Duckweed 

Lemna gibba 

TGAI 

98.6% 

7-day EC50 >1205 μg a.i./L 

NOAEC =1205 μg a.i./L 

No treatment related effects 

(47615015) 

*Chronic toxicity data for estuarine/marine fish and invertebrates are not available, therefore, a NOAEC was derived 

using an acute to chronic ratio (ACR) based on freshwater fish and invertebrate data, respectively. 

1

 The calculated ACR was 2.9 (Freshwater fish LC 50/Freshwater fish NOAEC = 290 μg a.i./L/100 μg a.i./L), and the 

resulting estimated chronic estuarine/marine fish NOAEC value was 476.2 μg a.i./L (1381 μg a.i./L/2.9). 2

 The calculated ACR was 5.37 (Freshwater invertebrate EC50/Freshwater invertebrate NOAEC = 2531 μg a.i./L/471 

μg a.i./L), and the resulting estimated chronic estuarine/marine invertebrates NOAEC value was 223 μg a.i./L (1200 

μg a.i./L/5.37). 
54

3.3.2.1. Toxicity to Freshwater Fish 

TGAI Penthiopyrad 

As shown in Table 3.16, four freshwater fish acute toxicity studies using the TGAI (98.6%) were 

submitted to evaluate the toxicity of penthiopyrad to fish in support of the new chemical 

registration. Three submitted acute toxicity studies with freshwater fish were classified as 

acceptable, and showed both lethal and sublethal effects to the test species. Observed sublethal 

effects included loss of equilibrium, lying on the bottom of the test chamber, lethargy, surfacing, 

haemorrhage, and reduced activity. These were observed in both organisms that recoverd, and 

organisms that died. The reported 96-hr LC50 values fall in the range of 290 to 572 μg a.i./L; 

therefore, penthiopyrad technical (MTF-753) is classified as highly toxic to freshwater fish on an 

acute exposure basis. 

Table 3.16. Freshwater Fish Acute Toxicity to Penthiopyrad Technical (TGAI).

Test Species/ 

Test Substance 

(Flow-through/Static)

% 

a.i. 

96-hour LC50 

(95% C.I.) 

(μg a.i./L, mean-measured) 

Slope 

Toxicity 

Category MRID Study Classification

Fathead Minnow 

(Pimephales promelas) 

Penthiopyrad technical 

(TGAI); (Static) 

98.6 

290 μg a.i./L 

(95% CI 203-414 μg a.i./L) 

Slope = NA 

Highly 

toxic 47614988 Acceptable 

Rainbow trout 

(Oncorhynchus mykiss) 

Penthiopyrad technical 

(TGAI); (Static) 

98.6 

386 μg a.i./L 

(95% CI 276-540 μg a.i./L) 

Slope = NA 

Highly 

toxic 47614984 Acceptable 

Common Carp 

(Cyprinus carpio) 

Penthiopyrad technical 

(TGAI); (Flowthrough) 

98.6 

572 μg a.i./L 

(95% CI 434-685 μg a.i./L) 

Slope = NA 

Highly 

toxic 47614986 Supplemental 

Slope = NA - Probit slope calculations were not available; binomial method was used as there were less than two 

concentrations with partial mortality 

A freshwater fish chronic early life stage toxicity test was submitted for fathead minnow 

(Pimephales promelas) with penthiopyrad technical (TGAI; 98.6%) (Table 3.17). The test was 

conducted for 33 days under flow-through conditions. There was a significant difference in 

percent post-hatched (larval) survival (69% reduction), total length (9.2% reduction) and dry 

weight (10.8% reduction) in the highest test concentration (188 μg a.i./L) in comparison to 

control fish. Which correspond to NOAEC and LOAEC values of 100 μg a.i./L and 188 μg 

a.i./L, respectively. Observed sublethal effects included being smaller in size, weak, curled, 

discoloured, and/or curved (crooked) spines; morphologically-deformed (i.e., swollen abdomen), 

surfacing, lying on the bottom, injured side, and/or a loss in equilibrium; however the effects did 

not increase in a dose-response manner, and were comparable to the control groups. 
55

Table 3.17. Freshwater Fish Chronic Toxicity to Penthiopyrad Technical (TGAI).

Test Species 

(Flow-through/Static; 

Duration)

% 

a.i. 

NOAEC/LOAEC 

(μg a.i./L, mean-measured) Effect MRID Study 

Classification

Fathead minnow 

(Pimephales promelas) 

(Flow-through; 33 days) 

98.6 NOAEC = 100 μg a.i./L 

LOAEC = 188 μg a.i./L 

Growth 

(total length & 

dry weight) 

47614994 Acceptable 

Formulated Products 

There were three additional freshwater fish acute static toxicity studies using the three 

formulated products Fontelis, Vertisan, and Treoris. The two additional freshwater fish toxicity 

studies using the formulated products Fontelis, and Treoris tested the rainbow trout 

(Oncorhynchus mykiss), and the study submitted using the formulation Vertisan tested the 

fathead minnow (Pimephales promelas), (Table 3.18). Based on the results of these studies, a 

96-hr LC50 value of 356 μg a.i./L was reported for Fontelis, a 96-hr LC50 value of 309 μg a.i./L 

was reported for Vertisan and a 96-hr LC50 value of 14 μg penthiopyrad a.i./L was reported for 

Treoris. In addition to lethal effects, sublethal effects (i.e., loss of equilibrium, lethargy, lying on 

the bottom, hyperventilation, and surfacing) were also observed. Penthiopyrad corrected toxicity 

endpoints for Fontelis and Vertisan formulations are similar in toxicity endpoints for the 

technical grade penthiopyrad and are classified as highly toxic to freshwater fish on an acute 

exposure basis. The Treoris formulation is considerably more toxic than technical grade 

penthiopyrad; the 96-hr LC50 for Treoris formulation was 14.0 μg penthiopyrad a.i./L (MRID 

47737323), which is 21 times more toxic than compared to the 96-hr LC50 for the technical grade 

penthiopyrad (290 μg a.i./L; MRID 47614988). The toxicity of the Treoris formulation in terms 

of the chlorothalonil acitive ingredient is less toxic (25.4 μg chlorothalonil a.i./L (MRID 

47737323) as compared to 10.5 μg a.i./L for technical grade chlorothalonil (Davies and White 

1985)). However, these results indicate that the increase in toxicity of Treoris as compared to the 

technical penthiopyrad and other penthiopyrad formulations is due to the high toxicity of the 

chlorothalonil, and is not considered to be a synergistic effect of the combination of 

penthiopyrad plus chlorothalonil. Therefore, based on these results, the Treoris formulation is 

classified, in terms of the active ingredient penthiopyrad, as very highly toxic to freshwater fish 

on an acute exposure basis. 

Table 3.18. Freshwater Fish Acute Toxicity to the Fontelis, Vertisan, and Treoris 

Formulations.

Test Species/ 

Test Substance 

(Flow-through/Static)

% 

a.i. 

96-hour LC50 

(95% C.I.) 

(μg a.i./L, mean-measured) 

Slope 

Toxicity 

Category MRID Study Classification

Rainbow trout 

(Oncorhynchus mykiss) 

Fontelis

(Static) 

20.72 

356 μg a.i./L 

(95% CI 190-800 μg a.i./L) 

Slope = NA 

Highly 

toxic 47615225 Acceptable 

Fathead Minnow 

(Pimephales promelas) 20.8 309 μg a.i./L (95% CI 224-546 μg a.i./L) 

Highly 

toxic 47615335 Acceptable 
56

Test Species/ 

Test Substance 

(Flow-through/Static)

% 

a.i. 

96-hour LC50 

(95% C.I.) 

(μg a.i./L, mean-measured) 

Slope 

Toxicity 

Category MRID Study Classification

Vertisan 

(Static) 

Slope = NA 

Rainbow trout 

(Oncorhynchus mykiss) 

Treoris 

(Static) 

8.91a 

22.8b

14.0 μg a.i./L 

(95% CI 7.34-22.2 μg a.i./L) 

penthiopyrad 

Slope = NA 

25.4 μg a.i./L 

(95% CI 11.6-51.1 μg a.i./L)

chlorothalonil 

Slope = NA 

Very 

highly 

toxic 

47737323 Supplemental 

Slope = NA - Probit slope calculations were not available; binomial method was used as there were less than two 

concentrations with partial mortality 

a

 Penthiopyrad active ingredient 

b

 Chlorothalonil active ingredient

Degradates 

Five penthiopyrad metabolite acute freshwater fish toxicity studies using the metabolites DMPCA, PCA, PAM, 753-A-OH, and 753-T-DO were submitted and are summarized in Appendix 

E. Based on the results of these tests, all tested penthiopyrad metabolites were found to be less 

toxic than the parent TGAI. Therefore, only the parent toxicity data will be considered to 

characterize the acute risk to fish. 

3.3.2.2. Toxicity to Freshwater Invertebrates 

TGAI Penthiopyrad 

Freshwater invertebrate acute toxicity data for the waterflea (Daphnia magna) are available for 

penthiopyrad TGAI and are presented in Table 3.19. The 48-hr EC50 value for Daphnia 

exposure to the penthiopyrad TGAI is 2531 μg a.i./L, classifying penthiopyrad technical as 

moderately toxic to freshwater invertebrates on an acute exposure basis. Sublethal effects 

included lethargy, immobilization and reduced activity. 
57

Table 3.19. Freshwater Invertebrate Acute Toxicity to Penthiopyrad Technical (TGAI).

Test Species/ 

Test Substance 

(Flow-through/Static)

% a.i. 

48-hour EC50

(95% C.I.) 

(μg a.i./L, mean-measured) 

Slope 

Toxicity 

Category MRID Study Classification

Waterflea 

(Daphnia magna) 

Penthiopyrad technical 

(TGAI) 

(Static) 

98.8 

2531 g a.i./L 

(95% CI 2251-2829 g a.i./L) 

Slope = 10.3 (95% CI 6.06-14.5)

Moderately 

toxic 47614996 Acceptable 

Slope = NA - Probit slope calculations were not available; binomial method was used as there were less than two 

concentrations with partial mortality/immobility 

A chronic 21-day full life cycle toxicity test was submitted for aquatic freshwater invertebrates 

using the penthiopyrad TGAI (MRID 47615003). The result of the study is summarized in 

Table 3.20. The chronic full life cycle toxicity test using the TGAI, indicated statisticallysignificant (p<0.05) reduction in the mean number of live young per reproductive day in the two 

highest test concentrations (818 and 1515 μg a.i./L); the corresponding NOAEC and LOAEC are 

471 μg a.i./L and 818 μg a.i./L, respectively (MRID 47615003). 

Table 3.20. Freshwater Invertebrate Chronic Toxicity to Penthiopyrad Technical.

Test Species 

(Flow-through/Staticrenewal; Duration)

% 

a.i. 

NOAEC/LOAEC 

(μg a.i./L, mean-measured) Effect MRID Study Classification

Waterflea 

(Daphnia magna) 

Penthiopyrad technical 

(TGAI) 

(Flow-through; 21 days) 

98.6 

NOAEC = 471 μg a.i./L 

LOAEC = 818 μg a.i./L 

Reproduction 

(time to first brood 

release, & the 

number of live 

offspring per 

reproductive day) 

47615003 Acceptable 

One additional spiked sediment toxicity study, which is summarized in Table 3.21, was 

submitted by the registrant to assess the potential effects of penthiopyrad on the sedimentdwelling freshwater invertebrate midge (Chironomus riparius). The study, which followed the 

Organization of Economic Cooperation and Development (OECD) Guideline 2186

 methods for 

sediment-water chironomid toxicity testing using spiked sediment, was classified as 

“Supplemental” because it is a non-guideline study. The results of the study indicate that 

penthiopyrad remained predominantly associated with the sediment during the 28-day study. 

Only two test concentrations (the lowest and highest) were analytically-determined in sediment, 

overlying water, and pore water from surrogate vessels, they were the concentrations prepared at 

the nominal 3.1 (low) and 100 (high) mg a.i./kg levels, and were measured on days 0, 7, and 28. 

The 100 mg a.i./kg nominal sediment test concentration was analytically analyzed with resulting 

time-weighted average (TWA) concentrations of 72.5 mg a.i./kg in the sediment, and 3.3 mg 

a.i./L in the overlying water and 5.4 mg a.i./L in the pore water. 

 

6

 OECD. 2011. Test No. 218: Sediment-Water Chironomid Toxicity Using Spiked Sediment. 

http://titania.sourceoecd.org/vl=65713224/cl=23/nw=1/rpsv/ij/oecdjournals/1607310x/v1n2/s19/p1 
58

There was a treatment-related effect observed on reduced survival (83% mortality; 68% 

reduction) and emergence rate (34% reduction) of adults at the highest nominal test 

concentration of 100 mg a.i./kg (measured as 5.4 mg a.i./L in the pore water) as compared to the 

negative control. However, since only the highest and lowest test concentrations were measured, 

the pore water NOAEC value is not known. To estimate the NOAEC in terms of pore water 

concentrations a ratio analysis using the LOAEC for the nominal sediment test concentration and 

the LOAEC for the measured pore water concentration was completed. The resulting ratio was 

calculated to be 18.35 (the nominal sediment concentration LOAEC/ the measured pore water 

concentration LOAEC = 100/5.4), this ratio was then compared to the NOAEC for the nominal 

sediment concentration to estimate the NOAEC for the pore water concentration. Based on the 

ratio analysis, the estimated NOAEC for the pore water concentration was calculated to be 2.72 

mg a.i./L (NOAEC for the nominal sediment concentration/ratio = 50/18.35). Therefore, based 

on these calculations the 28-day NOAEC and LOAEC were 2.72 and 5.4 mg a.i./L, respectively, 

based on pore water (estimated and measured, respectively) concentrations. 

Given the propensity for penthiopyrad to remain in the sediment, the endpoint associated with 

the concentrations in the pore water is used to assess the potential toxicity of penthiopyrad TGAI 

to sediment-dwelling freshwater invertebrates. 

Table 3.21. Toxicity of Sediment-Dwelling Freshwater Invertebrates to Penthiopyrad 

TGAI

Test Species 

Test Substance 

(Flow-through/Static; 

Duration)

% 

a.i. 

Endpoint 

 (Measured/Nominal) Effect MRID Study Classification 

Chironomus riparius 

Penthiopyrad technical 

(TGAI) 

(Spiked sediment; 

Static; 28 days) 

98.6 

Sediment:

NOAEC = 50 mg a.i./kg 

LOAEC = 100 mg a.i./kg 

(Nominal) 

LOAEC = 72.5 mg a.i./kg 

(Time-weighted average 

measured, TWA) 

Pore Water: 

NOAEC = 2.72 mg a.i./L* 

LOAEC = 5.4 mg a.i./L 

(TWA) 

Overlying Water: 

NOAEC = value could not be 

determined 

LOAEC = 3.32 mg a.i./L 

(TWA) 

Mortality 

& 

Emergence 

rate 

47615014 

Supplemental 

(non-guideline 

study) 

* Only the highest and lowest test concentrations were measured, therefore, to estimate the NOAEC based on pore 

water concentrations a ratio using the nominal sediment concentration LOAEC and measured pore water LOAEC 

was used. 
59

Formulated Products 

There were three additional freshwater invertebrate acute static toxicity studies using the three 

formulation products Fontelis, Vertisan, and Treoris, the data are presented in Table 3.22. The 

available acute data for the Fontelis formulation show that it is more toxic to freshwater 

invertebrates than technical grade penthiopyrad with a reported 48-hr EC50 value of 59.6 μg a.i./L 

(MRID 47615226). In addition, the corresponding NOAEC for sublethal effects (lethargy) was 

15.15 μg a.i./L. The available acute data for the Vertisan formulation show that it is slightly 

more toxic to freshwater invertebrates than technical grade penthiopyrad (48-hr EC50 =2531 μg 

a.i./L) with a reported 48-hr EC50 value of 1215 μg a.i./L (MRID 47615336). The corresponding 

NOAEC for sublethal effects (i.e., lethargy) was reported as <488 μg a.i./L. The Treoris 

formulation is more toxic than technical grade penthiopyrad; the 48-hr EC50 for Treoris was 18.5 

μg penthiopyrad a.i./L (MRID 47737324), which is roughly 137 times more toxic than the 48-

hr EC50 for the technical grade penthiopyrad (2531 μg a.i./L; MRID 47614996). The toxicity of 

the Treoris formulation in terms of the chlorothalonil acitive ingredient is equally toxic (45 μg 

chlorothalonil a.i./L (MRID 47737324) as compared to 54 μg a.i./L for technical grade 

chlorothalonil (MRID 45710221). These results indicate that the increased toxicity of this 

formulation compared to the technical penthiopyrad and other penthiopyrad formulations is 

likely due to chlorothalonil alone, and is not considered to be a result of a synergistic effect of 

the combination of penthiopyrad plus chlorothalonil. Therefore, based on these results, the 

Treoris formulation is classified, in terms of the active ingredient penthiopyrad, as very highly

toxic to freshwater invertebrates on an acute exposure basis. 

Table 3.22. Freshwater Invertebrate Acute Toxicity to the Fontelis, the Vertisan and the 

Treoris Formulations.

Test Species/ 

Test Substance 

(Flow-through/Static)

% a.i. 

48-hour EC50

(95% C.I.) 

(μg a.i./L, mean-measured) 

Slope 

Toxicity 

Category MRID Study 

Classification

Waterflea 

(Daphnia magna) 

Fontelis 

(Static) 

20.72 

59.6 μg a.i./L 

(95% CI 28.7-187.7 μg a.i./L) 

Slope = 2.19 (95% CI 0.646-3.74)

Very highly 

toxic 47615226 Acceptable 

Waterflea 

(Daphnia magna) 

Vertisan 

(Static)

20.8 

1215 μg a.i./L 

(95% CI 948-1920 μg a.i./L) 

Slope = NA 

Moderately 

toxic 47615336 Acceptable 

Waterflea 

(Daphnia magna) 

Treoris 

(Static)

8.91a 

22.8b

18.5 μg a.i./L 

(95% CI 12-25.8μg a.i./L) 

penthiopyrad 

Slope = NA 

45 μg a.i./L 

(95% CI 29.2-62.7 μg a.i./L) 

chlorothalonil 

Slope = NA 

Very highly 

toxic 47737324 Acceptable 
60

Slope = NA - Probit slope calculations were not available; binomial method was used as there were less than two 

concentrations with partial mortality/immobility 

a

 Penthiopyrad active ingredient 

b

 Chlorothalonil active ingredient.

A chronic 21-day full life cycle toxicity tests was submitted for aquatic freshwater invertebrates, 

using the Fontelis formulation (MRID 47615236). The result of the study is summarized in 

Table 3.23. The chronic full life cycle toxicity test using the Fontelis formulation indicated 

statistically-significant (p<0.05) reductions in the mean adult survival, the mean number of live 

your produced per surviving female, and the mean adult length in the highest test concentraition 

(20.75 μg a.i./L); corresponding to a NOAEC and LOAEC of 10.61 μg a.i./L, and 20.75 μg 

a.i./L, respectively (MRID 47615236). The chronic daphnid toxicity data for the Fontelis 

formulation show that it is 44 times more toxic than the TGAI to freshwater invertebrates on a 

chronic exposure basis. 

Table 3.23. Freshwater Invertebrate Chronic Toxicity to the Fontelis Formulation.

Test Species 

(Flow-through/Staticrenewal; Duration)

% 

a.i. 

NOAEC/LOAEC 

(μg a.i./L, mean-measured) Effect MRID Study Classification

Waterflea 

(Daphnia magna) 

Fontelis

(Static-renewal; 21 

days) 

21.0 

NOAEC = 10.61 μg a.i./L 

LOAEC = 20.75 μg a.i./L 

Adult mortality, 

clinical signs of 

toxicity, time to 

first brood, 

number of live 

offspring per 

surviving adult, 

and length 

47615236 Acceptable 

Degradates 

Acute freshwater invertebrate toxicity studies using the metabolites DM-PCA, PCA, PAM, 753-

A-OH, and 753-T-DO were submitted and are summarized in Appendix E. Based on the results 

of these tests, the penthiopyrad metabolites DM-PCA, PCA, and PAM were found to be less 

toxic than the parent penthiopyrad active ingredient. However, the toxicity of two minor 

degradates, 753-A-OH and 753-T-DO, were found to be within an order of magnitude of the 

parent TGAI; although non-definitive, there is still a potential for effects resulting from exposure 

to these two metabolites. However, the inclusion of the two minor degradates 753-A-OH, and 

753-T-DO in exposure modeling would not appreciably increase exposure estimates. Since the 

major degradates of penthiopyrad were much less toxic to aquatic invertebrates than the parent 

compound, penthiopyrad alone was modeled to estimate exposure for aquatic organisms in this 

assessment. The parent toxicity data alone are used to characterize the acute risk to 

invertebrates. 
61

3.3.2.3. Toxicity to Estuarine/Marine Fish 

TGAI Penthiopyrad 

One estuarine/marine fish acute toxicity study with the TGAI was required to evaluate the 

toxicity of penthiopyrad to fish in support of the new registration. Results from the submitted 

estuarine/marine fish acute toxicity tests are listed in Table 3.24 below. For the TGAI study, 

mortality was observed in the highest test concentration (1447 μg a.i./L) and sublethal effects 

(including: surfacing, lethargy, lying on the bottom of the test chamber, and loss of equilibrium) 

were observed at the two highest test concentrations (996 and 1447 μg a.i./L); the 96-hr LC50

value for sheepshead minnow (Cyprinodon variegates) is 1381 μg a.i./L. Therefore, 

penthiopyrad technical is classified as moderately toxic to estuarine/marine fish on an acute 

exposure basis. 

Table 3.24. Estuarine/Marine Fish Acute Toxicity to Penthiopyrad Technical (TGAI).

Test Species 

(Static/Static-renewal)

% 

a.i. 

96-hour LC50 

(95% C.I.) 

(μg a.i./L, mean-measured) 

Slope 

Toxicity 

Category MRID Study Classification

Sheepshead Minnow 

(Cyprinodon 

variegatus) 

Penthiopyrad technical 

(TGAI) 

(Static-renewal) 

98.6 

1381 μg a.i./L 

(95% CI 996-infinity μg a.i./L) 

Slope = NA 

Moderately 

toxic 47615034 Acceptable 

Slope = NA - Probit slope calculations were not available; binomial method was used as there were less than two 

concentrations with partial mortality 

Chronic toxicity data for estuarine/marine fish are not available. It is possible to derive an acuteto-chronic ratio (ACR) for estuarine/marine fish based on freshwater fish data. An ACR of 2.9 

was derived from the acute and chronic toxicity endpoints (i.e., 96-hr LC50 = 290 μg a.i./L and 

NOAEC = 100 μg a.i./L) available for the fathead minnow. When this ACR is applied to the 96-

hr LC50 for the sheepshead minnow (1381 μg a.i./L), the resulting estimated chronic 

estuarine/marine fish NOAEC is 476.2 μg a.i./L. The calculation of the ACR was completed 

between two different species of fish, which increases the uncertainty as to what degree 

penthiopyrad may have chronic effects on estuarine/marine fish. But the calculation of an ACR 

still provides valuable information in helping to discuss the possible chronic toxicity of 

penthiopyrad to estuarine/marine fish. 
62

Formulated Products 

In addition, one estuarine/marine fish acute toxicity study with the Fontelis formulation was 

submitted (Table 3.25). For the Fontelis formulation, mortality was observed in the highest test 

concentration (3790 μg a.i./L) and sublethal effects (including: surfacing, lethargy, lying on the 

bottom of the test chamber, and loss of loss of equilibrium) were observed at the two highest test 

concentrations (1830 and 3790 μg a.i./L); the formulation’s 96-hr LC50 value for sheepshead 

minnow (Cyprinodon variegates) is 2634 μg a.i./L. A precipitate was observed in all but the 

lowest test concentrations, and the test material was not centrifuged prior to being measured. 

Failure to centrifuge is an important flaw in the study design, and it raises the concern of 

potentially underestimating the toxicity of the Fontelis formulation. Although the samples were 

mixed with a top-down mixer, this still raises a concern that the samples may not represent only 

soluble penthiopyrad concentrations. Therefore, the Fontelis formulation is also classified, in 

terms of the active ingredient penthiopyrad, as moderately toxic to estuarine/marine fish on an 

acute exposure basis. 

Table 3.25. Estuarine/Marine Fish Acute Toxicity to the Fontelis Formulation.

Test Species 

(Static/Static-renewal)

% 

a.i. 

96-hour LC50 

(95% C.I.) 

(μg a.i./L, mean-measured) 

Slope 

Toxicity 

Category MRID Study Classification

Sheepshead Minnow 

(Cyprinodon 

variegatus) 

Fontelis 

(Static) 

21.0 

2634 μg a.i./L 

(95% C.I.: 1830-3790 μg a.i./L)

Slope = NA 

Moderately 

toxic 47615232 Supplemental 

Slope = NA - Probit slope calculations were not available; binomial method was used as there were less than two 

concentrations with partial mortality 

3.3.2.4. Toxicity to Estuarine/Marine Invertebrates 

Penthiopyrad TGAI 

Estuarine/marine invertebrate acute toxicity data for penthiopyrad technical is summarized in 

Table 3.26. The 96-hr LC50 value for mysid shrimp (Americamysis bahia) exposure to the TGAI 

is > 1700 μg a.i./L, classifying penthiopyrad technical as moderately toxic to estuarine/marine 

invertebrates on an acute exposure basis (MRID 47615032). In a 96-hr flow-through shell 

deposition study with estuarine/marine mollusks, the EC50 value for the Eastern oyster 

(Crassostrea virginica) based on mean shell deposition was 1200 μg a.i./L, the highest exposure 

concentration tested. A precipitate was observed in the diluter mixing cups for the two highest 

treatment concentrations for the duration of the test. The test samples were appropriately 

centrifuged prior to measurement to account for the total soluble concentrations of penthiopyrad. 

Based on the available data, it appears that penthiopyrad technical is moderately toxic to oysters 

on an acute exposure basis. 
63

Table 3.26. Estuarine/Marine Invertebrates Acute Toxicity to Penthiopyrad Technical.

Test Species 

Test Substance 

(Flow-through/Static)

% 

a.i. 

96-hour LC/EC50 

(95% C.I.) 

(μg a.i./L, mean-measured) 

Slope 

Toxicity 

Category MRID Study Classification

Mysid 

(Americamysis bahia) 

Penthiopyrad technical 

(TGAI) 

(Flow-through) 

98.6 LC50 > 1700 μg a.i./L 

Slope = NA 

Moderately 

toxic 47615032 Acceptable 

Eastern oyster 

(Crassostrea virginica) 

Penthiopyrad technical 

(TGAI) 

(Flow-through) 

98.6 

Shell deposition EC50 = 

1200 μg a.i./L 

(95% CI 940-1400 μg a.i./L) 

Slope = 3.59 ± 1.33 

Moderately 

toxic 47615033 Acceptable 

Chronic toxicity data for estuarine/marine invertebrates are not available. It is possible to derive 

an acute-to-chronic ratio (ACR) for estuarine/marine invertebrates based on freshwater 

invertebrate data. An ACR of 5.37 was derived from the acute and chronic toxicity endpoints 

(i.e., 48-hr EC50 = 2531 μg a.i./L and NOAEC = 471 μg a.i./L) available for Daphnia magna. 

When this ACR is applied to the 96-hr EC50 for the eastern oyster (1200 μg a.i./L), the resulting 

estimated chronic estuarine/marine invertebrates NOAEC is 223 μg a.i./L. When this ACR is 

applied to the 96-hr EC50 for the mysid shrimp (>1700 μg a.i./L), the resulting estimated chronic 

estuarine/marine invertebrates NOAEC is >316 μg a.i./L. The calculation of the ACR was 

completed between two different species of invertebrates, which increases the uncertainty as to 

what degree penthiopyrad may have chronic effects on estuarine/marine invertebrates. But the 

calculation of an ACR still provides valuable information in helping to discuss the possible 

chronic toxicity of penthiopyrad to estuarine/marine invertebrates. 

3.3.2.5. Toxicity to Aquatic Plants 

Acute aquatic plant toxicity studies were submitted for non-vascular and vascular plants using 

the penthiopyrad TGAI, the Fontelis, and Treoris formulations. The results of these studies are 

summarized in Table 3.27. 

Penthiopyrad TGAI 

Non-Vascular Aquatic Plants

Non-vascular aquatic plant data were submitted for freshwater green algae (Pseudokirchneriella 

subcapitata), freshwater blue-green (cyanobacteria) algae (Anabaena flos-aquae), freshwater 

diatom (Navicula pellicosa), and marine diatom (Skeletonema costatum) for the penthiopyrad 

technical. The results of the acute non-vascular plant data, which are discussed in further detail 

below, indicate the following sensitivity to penthiopyrad technical of the species tested: marine 

diatom > freshwater green algae > freshwater blue-green algae > freshwater diatom. For the 

freshwater green algae (P. subcapitata), the 96-hr EC50 and NOAEC values were 1600 μg a.i./L 

and 938 μg a.i./L, respectively, based on cell density (MRID 47615005). However, the most 
64

sensitive endpoint for aquatic non-vascular plants is the marine diatom (S.costatum) with a the 

96-hr EC50 and NOAEC values of 1200 μg a.i./L and 417 μg a.i./L, respectively, based on 

decreased cell density (MRID 47615006). For the freshwater blue-green algae (Anabaena flosaquae) and the freshwater diatom (Navicula pellicosa) the 96-hr EC50 and NOAEC values were 

>1660 μg a.i./L and 1660 μg a.i./L, and > 1470 μg a.i./L and 1470 μg a.i./L, respectively, no 

effects were observed in the highest test concentration (MRIDs 47615007 and 47615008). The 

results of these studies are summarized in Table 3.27. 

Vascular Aquatic Plants

Acute vascular aquatic plant data for penthiopyrad technical was submitted for duckweed 

(Lemna gibba). The 7-day EC50 and NOAEC values for technical penthiopyrad were >1205 μg 

a.i./L and 1205 μg a.i./L, respectively, based on no detectable effects on frond number, growth 

rate and biomass. Results are summarized in Table 3.27. 

Formulated Products 

Non-Vascular Aquatic Plants

There were two additional non-vascular plant (green algae P. subcapitata) toxicity studies using 

two formulated products Fontelis, and Treoris. The available acute data for the Fontelis 

formulation show that it is as equally toxic to freshwater green algae as the penthiopyrad 

technical with a reported 96-hr EC50 value of 1400 μg a.i./L based on cell density and a NOAEC 

value of 250 μg a.i./L, based on decreased cell density, biomass and growth rate (MRID 

47615230). The available acute data for the Treoris formulation show that it is more toxic to 

freshwater green algae than penthiopyrad technical with a reported 72-hr EC50 and NOAEC 

values of 51 μg penthiopyrad a.i./L and 35.6 μg penthiopyrad a.i./L, respectively, based on 

decreased cell density (MRID 47737325), which is two orders of magnitude (31 times) more 

toxic than compared to the 96-hr EC50 for the TGAI (EC50 =1600 μg a.i./L MRID 47615005). 

The toxicity of the Treoris formulation in terms of the chlorothalonil active ingredient is equally 

toxic (170 μg chlorothalonil a.i./L (MRID 47737325) as compared to 190 μg a.i./L for technical 

grade chlorothalonil (MRID 42432801). These results indicate that the increase in toxicity of 

this formulation compared to the technical penthiopyrad and other penthiopyrad formulations is 

likely due to the toxicity of the chlorothalonil active ingredient alone, and is not considered to be 

a synergistic effect of the combination of penthiopyrad plus chlorothalonil. Therefore, 

penthiopyrad TGAI alone was modeled to estimate exposure for aquatic plants in this 

assessment. Results are summarized in Table 3.27. 

Vascular Aquatic Plants

No vascular plant toxicity studies were submitted for any of the formulations of penthiopyrad. 

Degradates 

In addition, there were five acute non-vascular plant studies using the five metabolites of 

penthiopyrad (DM-PCA, PCA, PAM, 753-A-OH and 753-T-DO) submitted and are summarized 

in Appendix E. Based on the results of these tests, the penthiopyrad metabolites DM-PCA, 

PCA, and PAM were found to be less toxic than the parent penthiopyrad active ingredient. 
65

However, the two minor degradates753-A-OH and 753-T-DO were found to be within an order 

of magnitude of the toxicity of the parent TGAI to freshwater green algae, although nondefinitive, there is still a potential for effects resulting from exposure to these two metabolites. 

However, the inclusion of 753-A-OH, and 753-T-DO in exposure modeling would not 

appreciably increase exposure estimates, and the major degradates of penthiopyrad were much 

less toxic to aquatic non-vascular plants than the parent compound. Therefore, penthiopyrad 

TGAI alone was modeled to estimate exposure for aquatic plants in this assessment. 

Table 3.27. Acute Toxicity of Aquatic Plants to Penthiopyrad Technical, Fontelis and the 

Treoris Formulations. 

Test Species 

(Test Substance; 

Flow-through/Static; 

Duration)

% 

a.i. 

Endpoint 

(95% C.I.) 

(μg a.i./L, Measured) 

Slope 

Effect MRID Study 

Classification 

Non-vascular Plants: Freshwater Green Algae 

Freshwater green 

algae 

Pseudokirchneriella 

subcapitata

(TGAI; Static; 72 hr) 

98.8 

72-hr EC50 = 2200 μg a.i./L 

(95% CI 2000-2400 μg a.i./L) 

NOAEC = 450 μg a.i./L 

EC05 = 610 μg a.i./L 

(Mean-measured) 

Slope = 2.96 ± 0.225 

Cell 

density 47615004 Supplemental 

Freshwater Algae 

Pseudokirchneriella 

subcapita

(TGAI; Static; 96 hr) 

98.6 

96-hr EC50 = 1600 μg a.i./L 

(95% CI 1400-1900 μg a.i./L) 

NOAEC = 938 μg a.i./L 

EC05 = 760 μg a.i./L 

(Initial-measured) 

Slope = 4.98 ± 2.08

Cell 

density 47615005 Acceptable 

Freshwater green 

algae 

Pseudokirchneriella 

subcapitata

(Fontelis; Static; 72hr) 

21.0 

72-hr EC50 = 1400 μg a.i./L 

(95% CI 1000-1500 μg a.i./L) 

NOAEC = 250 μg a.i./L 

EC05 = 390 μg a.i./L 

(Mean-measured) 

Slope 2.98 ± 0.342 

Cell 

density 47615230 Supplemental 

Freshwater green 

algae 

Pseudokirchneriella 

subcapitata

(Treoris; Static; 72 hr) 

8.91a 

22.8b

72-hr EC50 = 51 μg a.i./L 

(95% CI 34-76 μg a.i./L) 

NOAEC = 35.6 μg a.i./L 

EC05 = 18 μg a.i./L 

(Mean-measured) 

Slope 3.68 ± 1.18 

Penthiopyrad 

72-hr EC50 = 170 μg a.i./L 

(95% CI 130-220 μg a.i./L) 

NOAEC = 105 μg a.i./L 

EC05 = 65 μg a.i./L 

(Initial-measured) 

Slope 4.01 ± 0.771 

Chlorothalonil 

Cell 

density 47737325 Supplemental 
66

Test Species 

(Test Substance; 

Flow-through/Static; 

Duration)

% 

a.i. 

Endpoint 

(95% C.I.) 

(μg a.i./L, Measured) 

Slope 

Effect MRID Study 

Classification 

Non-vascular Plants: Freshwater Blue-Green Algae, Freshwater Diatom, and Marine Diatom

Freshwater blue-green 

algae 

Anabaena flos-aquae 

(TGAI; Static, 96 hr)

98.6 

EC50 > 1660 μg a.i./L 

NOAEC = 1660 μg a.i./L 

 (Initial-measured) 

Slope = NA 

None 47615007 Acceptable 

Freshwater diatom 

Navicula pelliculosa 

(TGAI; Static, 96 hr) 

98.6 

96-hr EC50 >1470 μg a.i./L 

NOAEC = 1470 μg a.i./L 

 (Initial-measured) 

Slope = NA 

None 47615008 Acceptable 

Marine diatom 

Skeletonema costatum 

(TGAI; Static, 96 hr) 98.6 

96-hr EC50 = 1200 μg a.i./L 

(95% CI 1000-1500 μg a.i./L) 

NOAEC = 417 μg a.i./L 

EC05 = 390 μg a.i./L 

(Initial-measured) 

Slope = 3.30 ± 0.641 

Cell 

density 47615006 Acceptable 

Vascular Plants: Duckweed

Duckweed 

Lemna gibba 

(TGAI; Static; 7 days) 98.6 

7-D EC50 > 1205 μg a.i./L 

NOAEC = 1205 μg a.i./L 

 (Mean-measured) 

Slope = NA 

None 47615015 Acceptable 

* Bolded values will be used in risk characterization 

Slope = NA - Probit slope calculations were not available; no endpoints were affected. a

 Penthiopyrad active ingredient 

b

 Chlorothalonil active ingredient.

3.3.2 Terrestrial Effects Characterization 

A summary of the most sensitive terrestrial animal toxicity data for penthiopyrad technical and 

its formulated products is provided in Table 3.28 and discussed further in Sections 3.3.2.1

through 3.3.2.3. The available Tier II terrestrial plant toxicity data for penthiopyrad technical are 

provided in Section 3.3.2.4.

Table 3.28. Summary of the Most Sensitive Acute and Chronic Toxicity Data for 

Terrestrial Animals Exposed to Penthiopyrad.

Species/ 

Chemical 

Acute Toxicity Chronic Toxicity 

48-hr LD50 

(μg a.i./bee) 

14-day LD50

(mg/kg bw) 

(Toxicity 

Classification)

8-day LC50

(mg a.i./kg diet 

(ppm)) 

(Toxicity 

Classification)

 MRID 

NOAEC/LOAEC 

(mg a.i./kg diet 

(ppm)) 

(Endpoints) 

 MRID 

Bobwhite Quail 

(Colinus 

virginianus)/ 

(TGAI) 

NA 

>2,250 

(Practically 

non-toxic) 

>5,790 

(Practically 

non-toxic) 

 47614977 

& 

47614979 

5090 / >5090 

(No endpoints were 

affected) 

 47614982
67

Species/ 

Chemical 

Acute Toxicity Chronic Toxicity 

48-hr LD50 

(μg a.i./bee) 

14-day LD50

(mg/kg bw) 

(Toxicity 

Classification)

8-day LC50

(mg a.i./kg diet 

(ppm)) 

(Toxicity 

Classification)

 MRID 

NOAEC/LOAEC 

(mg a.i./kg diet 

(ppm)) 

(Endpoints) 

 MRID 

Mallard Duck 

(Anas 

platyrhynchos)/ 

(TGAI) 

NA ND 

>5,790 

(Practically 

non-toxic) 

47614981

1520 / 5090 

(Reductions in 

number of eggs laid 

and eggs set) 

 47614983

Wistar rat 

(Ratus 

norvegicus) / 

(TGAI) 

NA 

>2,000 

(Practically 

non-toxic) NA 47614875

Parental NOAEL 

=680 ppm 

(38 mg/kg bw/day) 

Parental LOAEL 

=1000 ppm 

(54 mg/kg bw/day) 

(Reduced body 

weight gain in F1

adult ♂, increased 

liver weight in P & F1

adult ♀ & increased 

relative adrenal 

weight with increased 

incidence of cortical 

hypertrophy in F1 ♀.)

Offspring NOAEL 

=1000 ppm 

(54 mg/kg/day) 

Offspring LOAEL 

=5000 ppm 

(278 mg/kg/day) 

(Reduced body 

weight & body 

weight gain, delay in 

preputial separation, 

& decrease in 

absolute thymus 

weights) 

47614906 

& 

47614907

Honey Bee 

(Apis mellifera)/ 

(TGAI) 

>500 

(Practically 

non-toxic) 

NA NA 47615017 NA NA

Honey Bee 

(Apis mellifera)/ 

Vertisan 

30.9

(Practically 

non-toxic) 

NA NA 47615337 NA NA

Honey Bee 

(Apis mellifera)/ 

Treoris 

>8.91 

(Moderately 

toxic) 

NA NA 47737326 NA NA

NA - Not Applicable; ND - No Data 
68

3.3.2.1. Toxicity to Birds 

Penthiopyrad TGAI 

Avian acute oral toxicity studies using the TGAI were submitted for bobwhite quail (Colinus 

virginianus) and zebra finch (Poephila guttata) to establish the toxicity of penthiopyrad techincal 

to birds. Results of these tests are presented in Table 3.29 below. The acute oral LD50 value for 

the bobwhite quail is >2,218 mg/kg body weight (bw); therefore, penthiopyrad is classified as 

practically non-toxic to upland avian species on an acute oral exposure basis. No 

sublethal/behavioral effects or treatment-related clinical signs of toxicity on body weight or feed 

consumption were observed. An acute oral LD50 value for the zebra finch could not be 

calculated due to significant regurgitation of the test material; 30% or more birds regurgitated the 

test material at the ≥156 mg/kg bw levels. Although, no mortalities were observed in any test 

concentration for the duration of the study; EFED determined that the observed regurgitation was 

an adverse effect of penthiopyrad (MRID 48489709). As a result, an effect dose (ED50) of 335 

mg/kg-bw was calculated using regurgitation as the effect. The NOAEL value was 93 mg/kgbw, the lowest concentration tested in which only one bird regurgitated. 

 

Table 3.29. Avian Acute Oral Toxicity to Penthiopyrad Technical, and the Fontelis 

Formulation.

Test Species % 

a.i. 

LD50 

(mg/kg bw) 

Slope 

Toxicity 

Category MRID Study Classification 

Northern bobwhite quail 

(Colinus virginianus) 

(TGAI) 

98.6 

>2,218 

Slope = NA Practically 

non-toxic 47614977 Acceptable 

Zebra Finch 

(Poephila guttata) 

(TGAI) 

98.6 

ED50 =335 

mg/kg bw1

 

Slope = NA 

Moderately 

toxic 47614978 Supplemental 

Northern bobwhite quail 

(Colinus virginianus) 

Fontelis 

21.0 >2,066 

Slope = NA Practically 

non-toxic 47615249 Acceptable 

1

 An effect dose (ED50) was calculated using regurgitation as the effect, due to significant regurgitation an accurate 

LD50 (lethal dose) could not be determined. 

NA - Probit slope calculations were not available; no mortality was observed. 

 

Avian sub-acute dietary toxicity tests were required for upland game and waterfowl bird species. 

Results of the two submitted tests are listed in Table 3.30 below. The LC50 values for the 

bobwhite quail and mallard duck are greater than the highest mean-measured treatment level of 

5,790 mg a.i./kg-diet; therefore, penthiopyrad technical is classified as practically non-toxic to 

avian species on a subacute dietary exposure basis. No treatment-related sublethal effects related 

to body weight changes, clinical signs of toxicity, or food consumption were observed in the 

mallard duck sub-acute dietary toxicity study. However, the NOAEC and LOAEC were 

determined using ANOVA, followed by William’s test for the bobwhite quail study. Based on 

the results, the reviewer concluded that body weight change was significantly (p<0.05) reduced 

at the 5790 mg a.i./kg bw level. Therefore, based on this effect a NOAEC value of 3320 mg 

a.i./kg-diet was reported for the bobwhite quail sub-acute dietary study. 
69

Table 3.30. Avian Subacute Dietary Toxicity to Penthiopyrad Technical (TGAI).

Test Species % 

a.i. 

8-Day LC50

(mg a.i./kg-diet) 

(Measured/Nominal) 

Slope 

Toxicity 

Category MRID Study Classification 

Northern bobwhite 

quail 

(Colinus virginianus) 

98.6 

>5,790 

(Mean-measured) 

Slope = NA 

Practically 

non-toxic 47614979 Acceptable 

Mallard duck 

(Anas platyrhynchos) 98.6 

>5,790 

(Mean-measured) 

Slope = NA 

Practically 

non-toxic 47614981 Acceptable 

NA - Probit slope calculations were not available; no effects were observed. 

Two avian reproduction tests using the TGAI were submitted to establish the chronic toxicity of 

penthiopyrad to birds. Results from these studies are summarized in Table 3.31 below. For the 

bobwhite quail study the control mortality in this study (12.5%; 3 females and 1 male out of 16 

pairs) exceeded the limit for an acceptable study. In addition, the effects that were seen in the 

necropsies of the dead control birds raise concerns relating to potential impacts on reproduction 

of the other control birds, resulting in an overall decrease in the mean number of eggs laid for the 

control birds. As a result, risk may potentially be underestimated, and the results are not reliable 

for use within the risk assessment. Therefore, the most sensitive chronic avian endpoint is based 

on a 12% and 13% reductions in the number of eggs laid and eggs set by mallard ducks the 

highest test concentration (5090 mg a.i./kg-diet), with a corresponding NOAEC of 1520 mg 

a.i./kg-diet. 

Table 3.31. Avian Chronic Toxicity (over 20 weeks) to Penthiopyrad Technical (TGAI).

Test Species % 

a.i. 

NOAEC/LOAEC 

(mg a.i./kg-diet) Effect MRID Study 

Classification 

Northern bobwhite 

quail 

(Colinus virginianus) 

98.6 

NOAEC =5090 

LOAEC >5090 None observed 47614982 Supplemental 

Mallard duck 

(Anas platyrhynchos) 

98.6 

NOAEC =1520 

LOAEC =5090 

Reduction in 

number of eggs 

laid & eggs set 

47614983 Acceptable 

Formulated Products 

In addition, an avian acute oral toxicity study was also submitted using the Fontelis formulation. 

Results of these tests are presented in Table 3.32. The LD50 value for the bobwhite quail 

exposed to the Fontelis formulation was >2066 mg a.i./kg bw and no lethal or sublethal 

treatment-related effects were observed. Therefore Fontelis is classified as practically non-toxic 

to upland avian species on an acute oral exposure basis. 
70

Table 3.32. Avian Acute Oral Toxicity to the Fontelis Formulation.

Test Species % 

a.i. 

LD50 

(mg/kg bw) 

Slope 

Toxicity 

Category MRID Study Classification 

Northern bobwhite quail 

(Colinus virginianus) 

Fontelis 

21.0 >2,066 

Slope = NA Practically 

non-toxic 47615249 Acceptable 

NA - Probit slope calculations were not available; no mortality was observed. 

3.3.2.2. Toxicity to Mammals 

Five mammalian acute oral toxicity studies using the TGAI and four metabolites (DM-PCA, 

PCA, PAM, and 753-A-OH) were submitted to establish the toxicity of penthiopyrad to 

mammals. Results of these tests are presented in Table 3.33 below. The acute mammalian oral 

LD50 values exceed 2,000 mg/kg bw; therefore, penthiopyrad and DM-PCA, PCA, and 753-AOH metabolites are classified as practically non-toxic to mammals on an acute oral exposure 

basis. However, the PAM metabolite acute oral LD50 value was > 300 mg/kg/bw (less than 2000 

mg/kg/bw), and therefore PAM is classified as moderately to slightly toxict to mammals on an 

acute oral exposure basis. No mortality, clinical signs, or macroscopic pathologic abnormalities 

were observed in rats exposed to penthiopyrad TGAI. Exposure to the DM-PCA, PCA, and 753-

A-OH metabolites of penthiopyrad resulted in no mortalities, clinical signs, or macroscopic 

pathologic abnormalities in any animal. Exposure to the PAM resulted in no mortalities in the 

groups treated with 300 mg/kg bw, but all animals treated with 2000 mg/kg bw died within 4-6 

hours of dosing. In addition, although there were no macroscopic findings at necropsy in any 

animal, and no clinical signs of an adverse reaction to treatment with 300 mg/kg bw. But at the 

2000 mg/kg bw death was preceded by decreased activity, tremor and clonic convulsion. 

Therefore the LD50 cut-off value (in accordance with the OECD test guideline 423, Annex 2) for 

PAM metabolite is 500 mg/kg bw for both female and male rats. The LD50 cut-off is based on 

guidance within the OECD 423 test guideline for acute oral toxicity testing, the guideline allows 

the classification of the test substance into a series of toxicity classes that are defined by a fixed 

cut-off LD50 value. The procedure follows a clear flow-chart and stepwise process to determine 

the LD50 values for the test substance. 

Table 3.33. Mammalian Acute Oral Toxicity to Penthiopyrad Technical (TGAI) and 

Metabolites (DM-PCA, PCA, PAM and 753-A-OH).

Test Species 

(Test Substance) % a.i. 

LD50 

(mg/kg- bw) 

Slope 

Toxicity 

Category MRID Study Classification 

Wistar rat 

(TGAI) 99.8 

>2,000 

Slope = NA Practically 

non-toxic 47614875 Acceptable 

Sprague-Dawley rat 

(DM-PCA) 99.71 

>2,000 

Slope = NA Practically 

non-toxic 47614918 Acceptable

Sprague-Dawley rat 

(PCA) 99.92 

>2,000 

Slope = NA Practically 

non-toxic 47614924 Acceptable
71

Test Species 

(Test Substance) % a.i. 

LD50 

(mg/kg- bw) 

Slope 

Toxicity 

Category MRID Study Classification 

Sprague-Dawley rat 

(PAM) 

99.97a 

100.0b

>300 <2,000 

(cut-off LD50=500)1

Slope = NA 

Moderately to 

slightly toxic 

47614930a

& 

47614931b 

Acceptable

Sprague-Dawley rat 

(753-A-OH) 98.91 

>2,000 

Slope = NA Practically 

non-toxic 47614936 Acceptable

1 Based on guidance within the OECD 423 test guideline for acute oral toxicity testing, the guideline allows the 

classification of the test substance into a series of toxicity classes that are defined by a fixed cut-off LD50 value. a

 MRID 47614930 - acute oral toxicity study using female Sprague-Dawley rats 

b

 MRID 47614931 - acute oral toxicity study using male Sprague-Dawley rats 

A 2-generation Wistar rat (Ratus norvegicus) reproduction study using the TGAI was submitted 

to establish the toxicity of penthiopyrad to mammals over prolonged periods. Results from this 

test are listed in Table 3.34 below. Based on reduced body weight gain in first generation (F1; 

offspring) adult males, increased liver weight in parental (P) and F1 adult females and increased 

relative adrenal weight with increased incidence of cortical hypertrophy in F1 females, the 

LOAEL and NOAEL for parental toxicity were reported as 54 and 38 mg/kg bw/day, 

respectively. The offspring toxicity LOAEL and NOAEL were reported as 278 and 54 mg/kg 

bw/day, respectively based on reduced body weight and body weight gain, delay in preputial 

separation, and a statistically significant (p<0.01) decrease in absolute thymus weights. 

 

Table 3.34. Mammalian Chronic Toxicity of Penthiopyrad Technical (TGAI)*

Test 

Species 

% 

a.i. 

NOAEL/ 

LOAEL 

(mg a.i./kg-diet; ppm) 

Effect MRID Study 

Classification 

Wistar rat 

(Ratus 

norvegicus) 

98.8 

Parental NOAEL =680 ppm 

(38 mg/kg bw/day) 

Parental LOAEL =1000 ppm 

(54 mg/kg bw/day) 

Offspring NOAEL =1000 ppm 

(54 mg/kg bw/day) 

Offspring LOAEL =5000 ppm 

(278 mg/kg bw/day) 

Reduced body weight 

gain in F1 adult ♂, 

increased liver weight 

in P and F1 adult ♀

and increased relative 

adrenal weight with 

increased incidence 

of cortical 

hypertrophy in F1 ♀. 

Reduced body weight 

and body weight gain, 

delay in preputial 

separation, and a 

statistically 

significant (p<0.01) 

decrease in absolute 

thymus weights. 

47614906 

& 

47614907 

Acceptable 

* Bolded values will be used in risk characterization 
72

3.3.2.3. Toxicity to Terrestrial Invertebrates and Beneficial Insects 

Honeybees

An acute contact toxicity study of bees is required, and 48-hr acute contact toxicity studies using 

penthiopyrad technical (TGAI), and the Fontelis, Vertisan, and Treoris formulations were 

submitted to establish the toxicity of penthiopyrad to young adult honeybees (Apis mellifera). In 

addition, non-guideline acute oral toxicity studies were submitted for the penthiopyrad technical 

(TGAI) and the Fontelis, Vertisan, and Treoris formulations. The results of the acute contact and 

acute oral studies are summarized in Table 3.35. 

There was no mortality of bees at the limit dose of 500 μg a.i./bee for penthiopyrad technical 

(TGAI), therefore, the reported LD50 value is >500 μg a.i./bee. However, this study was 

classified as supplemental, due to the failure of conducting a negative control concurrently with 

the solvent control and treatment groups. The Fontelis formulation, also found no treatmentrelated effects, sublethal effects (although classified as not being dose-dependent) observed 

included cramps (contracting abdomen or entire body), moribound (bees cannot walk and show 

only very feeble movements of legs and antennae, only weak response to stimulation (e.g., light, 

air movement), bees may recover but usually die, affected (bees still upright and attempting to 

walk but show signs of reduced co-ordination), and apathy (bees showing only slow or delayed 

reactions to stimulation (e.g., light, air movement); bees are either sitting motionless in the cage 

or staggering). However, based on the available information, and the non-dose response, the 

LD50 value was >100 μg a.i./bee, the highest concentration tested. 

For the Vertisan formulation, there was a dose-response increase in mortality of bees during the 

acute contact toxicity study and the calculated 48- and 96-hr LD50 values were 30.94 μg a.i./bee 

and 23.49 μg a.i./bee, respectively. Additionally, sublethal effects were also observed and 

included lying on their back, apathy (bees showing only slow or delayed reactions to stimulation 

(e.g., light, air movement); bees are either sitting motionless in the cage or staggering), and 

lethargy (bees walking slowly dragging their legs). For the Treoris formulation (co-formulated 

with chlorothalonil), after 48 hours observed a control mortality of 4% (two dead bees), which 

was corrected for, and based on this correction, no treatment related effects were observed. 

There was one bee that was observed at 48 hours to be lethargic (bees walking slowly dragging 

their legs), however, no other sublethal effects were obsereved; therefore, the LD50 value for the 

Treoris formulation was determined to be >8.91 μg penthiopyrad a.i./bee (equivalent to >22.8 μg 

chlorothalonil a.i./bee), the highest concentration tested. 

The results of the supplemental non-guideline acute oral toxicity studies of young adult 

honeybees with the penthiopyrad technical, the Fontelis, Vertisan, and Treoris formulations show 

similar results to the acute contact toxicity studies. For penthiopyrad technical, there was 3% 

mortality occurring at the single treatment concentration of 500 μg a.i./bee; the reported LC50

value is >500 μg a.i./bee. For the Fontelis formulation, no mortality was observed in any 

treatment concentration; therefore the LC50 value was >107.2 μg a.i./bee. For the Vertisan 

formulation, there was also a dose-response increase in mortality of bees during the acute oral 

toxicity study; therefore the calculated 48- and 96-hr LC50 values were 56.7 μg a.i./bee and 50.7 

μg a.i./bee, respectively. For the Treoris formulation, although there was mortality observed in 
73

each concentration, there was not a dose-dependent increase in mortality of bees during the acute 

oral toxicity study; therefore the 96-hr LC50 value is >10.9 μg penthiopyrad a.i./bee (equivalent 

to >28.1 μg chlorothalonil a.i./bee), the highest concentration tested. Although the endpoint 

values between the acute contact and acute oral studies appear to be slightly different, this 

difference can be attributed to the measured variations between dosing techniques. The same 

nominal concentrations were used in both the acute contact and acute oral toxicity tests for all 

test materials tested (the TGAI, and the Fontelis, Vertisan, and Treoris formulations). 

The penthiopyrad technical, the Fontelis, and the Vertisan formulations are all categorized as 

practically non-toxic to honey bees on an acute contact exposure basis. In terms of the active 

ingredient penthiopyrad, the Treoris formulation is categorized as moderately toxic to honeybees 

on an acute contact exposure basis. The toxicity of the Treoris formulation in terms of the 

chlorothalonil active ingredient is more toxic (>22.8 μg chlorothalonil a.i./L (MRID 47737326) 

when compared to the technical grade chlorothalonil (LD50>181 μg a.i./bee for (MRID 

00077759)) (Appendix F). In addition, it is important to highlight that chlorothalonil has been 

associated with numerous bee incidents, and chlorothalonil has been documented inside the hive, 

within bees, and it has also been found sequestered in bee pollen (Mullin et al., 2010). These 

incidents and data demonstrate that chlorothalonil is making its way back to the colony. 

Although, the available toxicity data indicates that the penthiopyrad technical does not result in 

effects to adult bees, the effects to bees in relation to the association of penthiopyrad and 

chlorothalonil in the co-formulated product, the Treoris formulation may increase the toxicity of 

penthiopyrad and chlorothalonil to bees. In addition, it should be noted that there are 

uncertainties associated with the honeybee toxicity data because they examine effects only on 

young adult forage (female) bees and not on potential effects to the queen, drones (males), 

juvenile (nurse) and larval bees. 

Table 3.35. Honeybee Acute Toxicity to Penthiopyrad Technical (TGAI) and the Fontelis, 

the Vertisan, and the Treoris formulations.

Test Species/ 

Test Substance 

Exposure 

Route % a.i. Endpoint 

Toxicity 

Category MRID Study Classification 

Honeybee 

(Apis mellifera) 

(TGAI)

Acute 

contact 98.8 48-hr LD50 >500 μg a.i./bee Slope = NA 

Practically 

non-toxic 47615017 Supplemental 

Acute oral 98.8 48-hr LC50 >500 μg a.i./bee 

Slope = NA N/A 47615016 

Supplemental 

(non-guideline 

study) 

Honeybee 

(Apis mellifera) 

Fontelis 

Acute 

contact 20.7 48-hr LD50 >100 μg a.i./bee 

Slope = NA

Practically 

non-toxic 47615237 Acceptable 

Acute oral 20.7 48-hr LC50 >107.2 μg a.i./bee

Slope = NA N/A 47615237 

Supplemental 

(non-guideline 

study) 
74

Test Species/ 

Test Substance 

Exposure 

Route % a.i. Endpoint 

Toxicity 

Category MRID Study Classification 

Honeybee 

(Apis mellifera) 

Vertisan 

Acute 

contact 20.8 

48-hr LD50 =30.9 μg a.i./bee 

(95% CI 21.6-49.9 μg a.i./bee)

Slope = 1.22 

(95% CI 0.95-1.48) 

96-hr LD50 = 23.5 μg a.i./bee 

(95% CI 17.0-35.4 μg a.i./bee)

Slope = 1.25 

(95% CI 1.00-1.51) 

Practically 

non-toxic 47615337 Acceptable 

Acute oral 20.8 

48-hr LC50 = 56.7 μg a.i./bee 

(95% CI 45.4-72.9 μg a.i./bee)

Slope = 1.50 

(95% CI 1.14-1.86) 

96-hr LC50 = 50.7 μg a.i./bee 

(95% CI 39.0-67.9 μg a.i./bee)

Slope = 1.24 

(95% CI 0.90-1.57) 

N/A 47615337 

Supplemental 

(non-guideline 

study) 

Honeybee 

(Apis mellifera) 

Treoris 

Acute 

contact 

8.91a 

22.8b

48-hr LD50 >8.91 μg 

penthiopyrad a.i./bee 

48-hr LD50 >22.8 μg 

chlorothalonil a.i./bee 

Slope = NA

Moderately

toxic 47737326 Acceptable 

Acute 

oral 

8.91a 

22.8b

48-hr LC50 >10.9 μg 

penthiopyrad a.i./bee 

48-hr LC50 >28.1 μg 

chlorothalonil a.i./bee 

Slope = NA 

N/A 47737326 

Supplemental 

(non-guideline 

study) 

Slope = NA - Probit slope calculations were not available; no endpoints were affected. 

N/A = Not applicable for acute oral toxicity; is not a guideline study 

a

 Penthiopyrad active ingredient 

b

 Chlorothalonil active ingredient.

Other Terrestrial Invertebrates and Beneficial Insects 

As shown in Table 3.36, additional terrestrial invertebrate toxicity studies were submitted for 

earthworms (Eisenia fetida), the parasitic wasp (Aphidius rhopalosiphi), the predatory mite 

(Typhlodromus pyri), the predatory bug (Orius laevigatus), and the green lacewing (Chrysoperla 

carnea). 

Earthworms 

The results of the earthworm acute toxicity tests with penthiopyrad technical, and the Fontelis 

formulation, show no treatment-related lethal or sublethal effects following 14-days of exposure 

at 1,000 mg a.i./kg dry weight (d.w.) of soil (acute); therefore, the reported LC50 values were 

>1000 mg/kg dw soil, the highest concentration tested. The results of the earthworm 

reproduction and growth toxicity studies with penthiopyrad technical show no treatment-related 

lethal or sublethal (growth or reproductive) effects following exposure; therefore, the reported 
75

NOAEC values were ≥ 48 mg/kg d.w. soil, the highest concentration tested. However, the 

reported results of the earthworm reproduction and growth toxicity study with the Fontelis 

formulation show a treatment-related decrease in body weight and reproduction in the 500 and 

1000 mg/kg d.w. soil test concentrations. Therefore, the NOAEC and LOAEC values for the 

Fontelis formulation were determined to be 250 and 500 mg/kg d.w. soil, respectively. 

Earthworm acute and reproduction toxicity studies using the metabolites DM-PCA, PCA, and 

PAM were submitted and are summarized in Appendix E. Based on the results of these tests, all 

tested penthiopyrad metabolites resulted in no treatment-related effects, similar to the parent 

penthiopyrad active ingredient. Therefore, only the parent toxicity data will be considered to 

characterize the risk (acute and reproductive) to earthworms on both an acute and chronic 

exposure basis. 

Beneficial Insects 

Effects on two sensitive species, the parasitic wasp, and the predatory mite, were studied in doseresponse tests on artificial substrate (glass plates) with the suspension concentrate Fontelis (20% 

penthiopyrad) and the emulsifiable concentrate Vertisan (20% penthiopyrad). The Fontelis 

formulation LR50 values (lethal rate to 50% of the test population) were equivalent to an 

application rate of 0.29 lbs a.i./A for the parasitic wasp (MRID 47615019), and and 0.11 lbs 

a.i./A for the predatory mite (MRID 47615239). The Vertisan formulation LR50 values were 

equivalent to an application rate of >0.211 lbs a.i./A for the parasitic wasp (MRID 47615338) 

and 0.266 lbs a.i./A for the predatory mite (MRID 47615339). 

In addition, extended laboratory studies were completed on the predatory mite, the predatory 

bug, and the green lacewing to examine the effects of penthiopyrad on mortality and 

reproduction (fecundity and fertility) with the suspension concentrate Fontelis (20.64% 

penthiopyrad) and the emulsifiable concentrate Vertisan (20.8% penthiopyrad). The Fontelis 

formulation 7-day LR50 (lethal rate to 50% of the test population) and 14-day ER50 (effect rate on 

reproduction to 50% of the test population) values for the predatory mite were equivalent to an 

application rate >2.49 lbs a.i./A and 1.91 lbs a.i./A, respectively (MRID 47615240). The 

Fontelis formulation 9-day LR50 and 18-day ER50 values for the green lacewing were both 

equivalent to an application rate of >2.49 lbs a.i./A (MRID 47615241). The Fontelis formulation 

9-day LR50 and 18-day ER50 values for the predatory bug were both equivalent to an application 

rate of >2.49 lbs a.i./A (MRID 47615242). The Vertisan formulation 7-day LR50 and 14-day 

ER50 values for the predatory mite were equivalent to an application rate of 0.0911 lbs a.i./A and 

>0.0911 lbs a.i./A, respectively (MRID 47615340). The Vertisan formulation 11-day LR50 and 

14-day ER50 values for the predatory bug were both equivalent to an application rate of >2.49 lbs 

a.i./A (MRID 47615341). The Vertisan formulation 23-day LR50 and ER50 values for the green 

lacewing were equivalent to application rates of 2.08 lbs a.i./A and >0.829 lbs a.i./A, 

respectively (MRID 47615342). 

It should be noted that the Fontelis formulation LR50 values for the parasitic wasp and predatory 

mite are approximately 1.3 to 4.3 times less than the maximum single application rate and 3 to 

10.3 times less than the maximum annual application rate for the Fontelis formulation of 

penthiopyrad (0.39 and 0.94 lbs a.i./A, respectively). The Vertisan formulation LR50 values for 
76

the predatory mite are approximately 1.5 times less than the maximum single application rate 

and 3.5 times less than the maximum annual application rate for the Vertisan formulation of 

penthiopyrad (0.39 and 0.94 lbs a.i./A, respectively). 

Table 3.36. Toxicity to Other Terrestrial Invertebrates and Beneficial Insects using 

Penthiopyrad Technical (TGAI), the Fontelis and the Vertisan formulations.

Test Species / 

Test Substance % a.i. Endpoint Effect MRID Study Classification 

Earthworm 

Eisenia fetida 

(TGAI) 

98.6 

14-day LC50 >1000 mg a.i./kg d.w. 

soil 

Slope = NA 

No effect 47615020 

Supplemental 

(non-guideline 

study) 

Earthworm 

Eisenia fetida 

Fontelis 

20.72 

14-day LC50 >1000 mg 

preparation/kg d.w. soil 

Slope = NA 

No effect 47615244 

Supplemental 

(non-guideline 

study) 

Earthworm 

Eisenia fetida 

(TGAI) 

98.6 NOAEC ≥ 48 mg/kg d.w. soil 

LOAEC > 48 mg/kg d.w. soil No effect 47615024 

Supplemental 

(non-guideline 

study) 

Earthworm 

Eisenia fetida 

Fontelis 

20.72 NOAEC = 250 mg a.i./kg d.w. soil

LOAEC = 500 mg a.i./kg d.w. soil

Decrease in 

body weight 

& 

reproduction

47615245 

Supplemental 

(non-guideline 

study) 

Parasitoid wasp 

Aphidius rholaposiph

Fontelis 

20.64 48-hr LR50 = 0.29 lbs a.i./A 

(3504.5 g/ha) Mortality 47615018 

Supplemental 

(non-guideline 

study) 

Parasitoid wasp 

Aphidius rholaposiph

Vertisan

20.8 48-hr LR50 >0.211 lbs a.i./A 

(>1.5 L/ha) Mortality 47615338 

Supplemental 

(non-guideline 

study) 

Predaceous mite 

Typhlodromus pyri 

Fontelis 

20.72 7-day LR50 =0.11 lbs a.i./A 

(0.62 L/ha) Mortality 47615238 

Supplemental 

(non-guideline 

study) 

Predaceous mite 

Typhlodromus pyri 

Vertisan 

20.8 7-day LR50 =0.266 lbs a.i./A 

(1.19 L/ha) Mortality 47615339 

Supplemental 

(non-guideline 

study) 

Predaceous mite 

Typhlodromus pyri 

Fontelis 

21.0 

7-day LR50 >2.49 lbs a.i./A 

(>14 L/ha; >2800 g a.i./ha) 

14-day ER50 =1.91 lbs a.i./A 

(10.78 L/ha; 2156 g a.i./ha) 

Reproduction 47615240 

Supplemental 

(non-guideline 

study) 

Green lacewing 

Chrysoperla carnea 

Fontelis 

21.0 

9-day LR50 >2.49 lbs a.i./A 

(>14 L/ha; >2800 g a.i./ha) 

18-day ER50 >2.49 lbs a.i./A 

(>14 L/ha; >2800 g a.i./ha) 

No effects 47615241 

Supplemental 

(non-guideline 

study) 

Predaceous bug 

Orius laevigatus 

Fontelis 

21.0 

9-day LR50 >2.49 lbs a.i./A 

(>14 L/ha; >2800 g a.i./ha) 

18-day ER50 >2.49 lbs a.i./A 

(>14 L/ha; >2800 g a.i./ha) 

No effects 47615242 

Supplemental 

(non-guideline 

study) 
77

Test Species / 

Test Substance % a.i. Endpoint Effect MRID Study Classification 

Predaceous mite 

Typhlodromus pyri 

Vertisan 

20.8 

7-day LR50 = 0.0911 lbs a.i./A 

(0.513 L/ha; 102.6 g a.i./ha) 

14-day ER50 >0.0911 lbs a.i./A 

(>0.513 L/ha; >102.6 g a.i./ha) 

Mortality 47615340 

Supplemental 

(non-guideline 

study) 

Predaceous bug 

Orius laevigatus 

Vertisan 

20.8 

11-day LR50 >2.49 lbs a.i./A 

(>14 L/ha; >2800 g a.i./ha) 

14-day ER50 >2.49 lbs a.i./A 

(>14 L/ha; >2800 g a.i./ha) 

No effects 47615341 

Supplemental 

(non-guideline 

study) 

Green lacewing 

Chrysoperla carnea 

Vertisan 

20.8 

23-day LR50 =2.08 lbs a.i./A 

(11.7 L/ha) 

23-day ER50 >0.829 lbs a.i./A 

(>4.67 L/ha) 

Mortality 47615342 

Supplemental 

(non-guideline 

study) 

3.3.2.4. Toxicity to Terrestrial Plants 

Two Tier I terrestrial non-target plant studies were submitted for the suspension concentrate 

Fontelis to assess the toxicity of penthiopyrad to terrestrial plants. The results of the non-target 

terrestrial plant studies for the suspension concentrate Fontelis are summarized in Table 3.37. 

Based on the results of the submitted Tier I seedling emergence toxicity test, application of 

Fontelis at the nominal maximum label rate of 1.42 lbs a.i./A (1600 g a.i./ha), (measured rate of 

1.39 lbs a.i./A, 1563 g a.i./ha for all species except sugarbeet; 1.44 lbs a.i., 1627 g a.i./ha for 

sugarbeet), resulted in the following adverse effects: 14% inhibition of seedling emergence and 

survival of ryegrass (Lolium perenne, based on number planted), 12% inhibition on growth (dry 

weight) of wheat (Triticum aestivum), and 20% inhibition on growth (dry weight) in tomato 

(Lycopersicon esculentum). No other endpoints were significantly affected, and overall, there 

were no species that had an inhibition of 25% or greater for any endpoint that was tested. 

Phytotoxic effects observed included leaf curl, necrosis, wilting, and stem curl. 

Based on the results of the submitted Tier I vegetative vigor toxicity test, application of Fontelis 

at the nominal maximum label rate of 1.42 lbs a.i./A (1600 g a.i./ha), (measured rate of 1.39 lbs 

a.i./A, 1563 g a.i./ha for wheat, corn, cabbage, soybean and lettuce; 1.44 lbs a.i./A, 1616 g a.i./ha 

for onion, ryegrass, sugarbeet, tomato and ryegrass), resulted in adverse effects on dry weight 

(20% inhibition) and height (5% inhibition) in wheat (Triticum aestivum), and dry weight (8% 

inhibition) in soybean (Glycine max). There were no adverse effects on seedling condition, 

survival, dry weight and height of the remaining terrestrial plant species tested, and overall, there 

were no species that had an inhibition of 25% or greater for any endpoint that was tested. 

Therefore, based on these results the EC25>1.39 lbs a.i./A for both seedling emergence and 

vegetative vigor studies. However, it was noted that definitive NOAEC’s were not obtained for 

ryegrass, wheat, and tomato (seedling emergence study), and wheat and soybean (vegetative 

vigor study), as these species exhibited treatment related reductions at the limit concentration 

relative to the negative control. Although Tier II studies are not required as no effects were 

greater than 25%, Tier II studies would reduce the uncertainty regarding Endangered Species 
78

assessments. Without a valid/definitive NOAEC value, risk to listed plant species would be 

assumed to an undefined area around the application site. 

Table 3.37. Summary of Tier I Toxicity of Fonetlis to Non-target Terrestrial Plants.

Plant type Test 

Species 

Seedling Emergence 

(MRID 47615037) 

Vegetative vigor 

(MRID 47615038) 

Test level 

(lb a.i./A) 

Endpoint(s) 

Affected 

Test level 

(lb a.i./A) 

Endpoint(s) 

Affected 

Monocots 

Corn 1.39 None 1.39 None 

Onion 1.39 None 1.44 None 

Ryegrass* 1.39 

Survival & seedling 

emergence 

(14% reduction) 

1.44 None 

Wheat* 1.39 Dry weight 

(12% reduction) 1.39 

Dry weight 

(20% recuction) 

& height 

(5% reduction) 

Dicots 

Sugarbeet 1.44 None 1.44 None 

Cabbage 1.39 None 1.39 None 

Soybean* 1.39 None 1.39 Dry weight 

(8% reduction) 

Lettuce 1.39 None 1.39 None 

Tomato* 1.39 Dry weight 

(20% reduction) 1.44 None 

Radish 1.39 None 1.44 None 

* These species exhibited statistically significant reductions at the limit concentration relative to the negative 

control; therefore, Tier II toxicity studies will be required for these species and the respective studies. 

4. Risk Characterization 

 4.1 Risk Estimation

Toxicity data and exposure estimates are used to evaluate the potential for adverse ecological 

effects on non-target species. As discussed previously, this baseline-level assessment of 

penthiopyrad relies on the deterministic RQ method to provide a metric of potential risks. The 

RQ provides a comparison of exposure estimates to toxicity endpoints (i.e., the estimated 

exposure concentrations are divided by acute and chronic toxicity values). The resulting RQs are 

compared to the Agency’s LOCs, as shown in Table 2.3. LOCs are used by the Agency to 

indicate when the use of a pesticide, as directed by the label, has the potential to cause adverse 

effects to non-target organisms. 

 

 4.1.1. Aquatic Organisms 

The highest baseline-level aquatic EECs were used to derive RQs. These exposure estimates 

were based on the proposed uses of penthiopyrad on cranberries (using the Tier I Rice Model) 

and on succulent lugumes (using the PE model) both at a maximum annual application rate of 
79

0.94 lbs a.i./A, and represent concentrations in surface water (exposure estimates for ground 

water were lower). Additionally, the lowest baseline-level aquatic EECs were also used to 

derive RQs, because listed species LOCs were exceeded based on the maximum use patterns and 

RQs for other use patterns resulting in lower EECs also exceeded LOCs. Peak EECs are used to 

represent acute exposure to fish, aquatic invertebrates, and aquatic plants, and the highest 21-day 

and 60-day average EECs represent chronic exposure to aquatic invertebrates and fish, 

respectively. In addition, to evaluate the acute risk to non-target aquatic organisms resulting 

from exposure to the Fontelis and Vertisan formulations via spray drift, EECs were calculated 

using AgDRIFT. 

4.1.1.1. Aquatic Animals 

Table 4.1 lists RQs calculated for aquatic animals exposed to penthiopyrad, based on the highest 

PE-calculated EECs listed in Table 3.6, which were for the proposed succulent legume use. The 

acute RQs based on the highest EECs for the proposed use patterns of penthiopyrad ranged from 

0.02 to 0.16. The freshwater fish were the only taxa that had an RQ above the Agency’s acute 

risk to listed species LOC of 0.05 (RQ = 0.16). Therefore, the lowest calculated EECs listed in 

Table 3.6, which were for the proposed canola use, were also used to calculate RQ values. The 

acute RQ for freshwater fish based on the lowest calculated EEC was 0.04; based on the secondto-lowest exposure estimate for the proposed use on sugarbeets, the acute RQ was 0.07. 

Therefore, RQs for freshwater fish (only) are above the Agency’s acute risk to listed species 

LOC of 0.05 for all proposed uses of penthiopyrad except canola (RQ values range from 0.04 to 

0.16). There were no acute risk LOC exceedances for estuarine/marine fish or freshwater and/or 

estuarine/marine invertebrates. 

As shown in Table 4.1, chronic RQ values for freshwater fish and invertebrates (including 

sediment-dwelling organsims) are less than the Agency’s LOC of 1.0 for chronic risk to fish and 

aquatic invertebrates, based on the highest EECs listed in Table 3.6 from the PRZM modeling 

scenario for the proposed succulent legume use. 

Table 4.1a lists acute and chronic RQs calculated for aquatic animals exposed to penthiopyrad 

from use on cranberries, based on the EEC from the Tier I Rice Model (529 μg/L). Acute RQs 

based on this EEC exceeded the LOC for non-listed freshwater fish (RQ = 1.8) and the LOC for 

listed estuarine/marine fish and freshwater and estuarine/marine invertebrates (RQ range 0.21-

0.44). The chronic RQs based on this EEC ranged from 1.1 to 5.3 for freshwater and 

estuarine/marine fish and invertebrates, indicating LOC exceedances for aquatic organisms. The 

chronic RQ value for sediment-dwelling organisms was 0.19, which is less than the Agency’s 

LOC of 1.0. Because the Tier I Rice Model is a poor estimator of exposure resulting from use on 

cranberries, additional provisional modeling is discussed in the risk description to characterize 

the potential risks from the proposed use on cranberries see Section 4.2.1. 

No chronic toxicity data are available for estuarine/marine fish or invertebrates using 

penthiopyrad technical (TGAI); therefore, the acute-to-chronic ratios were used to estimate a 

chronic NOAEC value for estuarine/marine fish and invertebrates. Based on the estimated 

chronic toxicity values for estuarine/marine fish, the chronic RQ value for estuarine/marine fish 
80

would also not exceed the Agency’s LOC of 1.0 for chronic risk to fish. Estuarine/marine fish 

(LC50 = 1381 μg a.i./L) are 4.8 times less sensitive to penthiopyrad on an acute exposure basis 

than freshwater fish (LC50 = 290 μg a.i./L). Therefore, using an ACR for freshwater fish and 

comparing the fathead and sheepshead minnow data, results in an ACR estimated NOAEC for 

sheepshead minnows of 476.2 μg a.i./L. To trigger the Agency’s chronic risk LOC, however, the 

estuarine/marine fish NOAEC would need to be at least 41 μg a.i./L (using the 60-day EEC and 

an LOC of 1) for every use except cranberries. Based on this calculation, estuarine/marine fish 

would need to be 2 times more sensitive to penthiopyrad (which is within the realm of 

interspecies variation) than freshwater fish on a chronic exposure basis to exceed the Agency’s 

chronic risk LOC for listed and non-listed species for every use except cranberry. However, for 

the cranberry use, using the EEC estimated from the Tier I Rice model (529 μg a.i./L) and an 

LOC of 1, the Agency’s chronic risk LOC is exceeded based on the estimated ACR for 

estuarine/marine fish. Therefore, chronic risk cannot be precluded for estuarine/marine fish due 

to this uncertainity. 

Estuarine/marine invertebrates (EC50 = 1200 μg a.i./L) are roughly twice as sensitive to 

penthiopyrad on an acute exposure basis than freshwater invertebrates (EC50 = 2531 μg a.i./L). 

Using a derived ACR of 5.37 for freshwater invertebrates and comparing the daphnid and 

Eastern oyster data results in an ACR estimated NOAEC for estuarine/marine invertebrates of 

223 μg a.i./L. To trigger the Agency’s chronic risk LOC, however, the estuarine/marine 

invertebrate NOAEC would need to be at least 44 μg a.i./L (using the 21-day EEC and an LOC 

of 1) for every use except cranberries. Based on this calculation, estuarine/marine invertebrates 

would need to be 9 times more sensitive to penthiopyrad (which is within the relm of interspecies 

variation) than freshwater invertebrates on a chronic exposure basis to exceed the Agency’s 

chronic LOC for listed and non-listed species for every use except cranberry. However, for the 

cranberry use, using the EEC estimated from the Tier I Rice model (529 μg a.i./L) and an LOC 

of 1, the Agency’s chronic risk LOC is exceeded based on the estimated ACR for 

estuarine/marine invertebrates. Therefore, chronic risk cannot be precluded for estuarine/marine 

invertebrates due to this uncertainity. 

Table 4.2 lists the RQs that were calculated to characterize the risk potential relating to nontarget aquatic organisms exposed to the Fontelis or Vertisan formulations via spray drift. RQs 

were based on the spray drift EECs that were calculated using AgDRIFT (see Section 3.2.2.1). 

The Fontelis formulation is classified as “highly toxic” to freshwater fish, and “very highly 

toxic” to freshwater invertebrates. The Vertisan formulation is classified as as “highly toxic” to 

freshwater fish and “moderately toxic” to freshwater invertebrates. The acute RQs based on the 

highest spray drift EEC for penthiopyrad using the Fontelis and/or Vertisan formulation (2.77 

μg/L, using the highest proposed agriculture use application rate of 0.39 lbs a.i./A) ranged from 

0.01 to 0.046. There were no acute risk LOC exceedances for freshwater animals for either the 

Fontelis or the Vertisan formulations. Toxicity to estuarine/marine invertebrates is not known, 

as there is no acceptable estuarine/marine fish or invertebrate toxicity data available for the 

Fontelis or Vertisan formulation. Without estuarine/marine fish or invertebrate toxicity data risk 

potential relating to non-target estuarine/marine organisms exposed to the Fontelis formulations 

via spray drift cannot be precluded. 
81

Further characterization of the available fish and aquatic invertebrate acute and chronic toxicity 

data for the penthiopyrad formulated products is also provided as part of the risk description in 

Section 4.2.1.1. 

Table 4.1. Aquatic Animal RQ Values for Exposure to Penthiopyrad TGAI Resulting from 

Proposed Uses Other Than Cranberries.

Taxa Exposure Endpoint Used 

(μg a.i./L) 

RQ values*

Based on Highest 

Surface Water EEC1

Based on Lowest 

Surface Water EEC2

Freshwater Fish Acutea LC50 = 290 0.16 0.04 

Estuarine/Marine Fish Acutea LC50 = 1381 0.03 <0.01 

Freshwater Invertebrates Acutea EC50 = 2531 0.02 <0.01 

Estuarine/Marine 

Invertebrates Acutea

 EC50 = 1200 0.04 0.01 

Freshwater Fish Chronicb NOAEC = 100 0.41 0.12 

Estuarine/Marine Fish Chronicb NOAEC = 476.23 0.09 0.03 

Freshwater Invertebrates Chronicc NOAEC = 471 0.09 0.03 

Estuarine/Marine 

Invertebrates Chronicc

 NOAEC = 2233 0.20 0.06 

Sediment-Dwelling 

Organisms Chronicd

 NOAEC = 27204 0.01 -- 

* Bolded values indicate RQs that exceed the Agency’s acute risk LOC (0.05 - listed species; or 0.5 - non-listed 

 species) or chronic risk LOC (1.0) 

1

 Based on the highest calculated surface water EEC value (45 μg/L) using PRZM/EXAMS - the proposed succulent 

legume use 

2

 Based on the lowest calculated surface water EEC value (13 μg/L) using PRZM/EXAMS - the proposed canola use 3

 ACR estimated NOAEC; chronic toxicity data for estuarine/marine fish and invertebrates are not available; 

therefore, a NOAEC was derived using an acute to chronic ratio (ACR) based on freshwater fish and invertebrate 

data, respectively, which was used to estimate the estuarine/marine fish and invertebrate RQ values. 4

 Only the highest and lowest test concentrations were measured, therefore, to estimate the NOAEC based on pore 

water concentrations a ratio (18.35) using the nominal sediment concentration LOAEC (100 mg a.i./kg) and 

measured pore water LOAEC (5.4 mg a.i./L) was used; See Section 3.3.2.2. a

 The peak EEC values for succulent legumes (45 μg/L) and canola (13 μg/L) were used to calculate acute RQ 

values for fish, aquatic invertebrates. 

b

 The 60-day EEC values for succulent legumes (41 μg/L) and canola (12 μg/L) were used to calculate chronic RQ 

values for fish. 

c

 The 21-day EEC values for succulent legumes (44 μg/L) and canola (13 μg/L) were used to calculate chronic RQ 

values for aquatic invertebrates. 

d

 The 21-day pore water EEC for succulent legumes (38 μg/L) was used to calculate chronic RQ values for sediment 

dwelling organisms. 
82

Table 4.1a. Aquatic Animal RQ Values for Exposure to Penthiopyrad TGAI Resulting 

from the Proposed Use on Cranberries (Tier I EEC).

Taxa Exposure Endpoint Used 

(μg a.i./L) RQ values*

Freshwater Fish Acutea LC50 = 290 1.8 

Estuarine/Marine Fish Acutea LC50 = 1381 0.38 

Freshwater Invertebrates Acutea EC50 = 2531 0.21 

Estuarine/Marine Invertebrates Acutea EC50 = 1200 0.44 

Freshwater Fish Chronica NOAEC = 100 5.3 

Estuarine/Marine Fish Chronica NOAEC = 4761 1.1 

Freshwater Invertebrates Chronica NOAEC = 471 1.1 

Estuarine/Marine Invertebrates Chronica NOAEC = 2231 2.4 

Sediment-Dwelling Organisms Chronica NOAEC = 27202 0.19 * Bolded values indicate RQs that exceed the Agency’s acute risk LOC (0.05 - listed species; or 0.5 - non-listed 

 species) or chronic risk LOC (1.0) 

1

 ACR estimated NOAEC; chronic toxicity data for estuarine/marine fish and invertebrates are not available; 

therefore, a NOAEC was derived using an acute to chronic ratio (ACR) based on freshwater fish and invertebrate 

data, respectively, which was used to estimate the estuarine/marine fish and invertebrate RQ values. 2

 Only the highest and lowest test concentrations were measured, therefore, to estimate the NOAEC based on pore 

water concentrations a ratio (18.35) using the nominal sediment concentration LOAEC (100 mg a.i./kg) and 

measured pore water LOAEC (5.4 mg a.i./L) was used; See Section 3.3.2.2. a

 The single EEC for cranberries from the Tier I Rice Model (529 μg/L) was used to calculate RQ values for each 

assessed taxon. 

Table 4.2. Aquatic Animal RQ Values for Exposure (via Spray Drift) to Fontelis and 

Vertisan Penthiopyrad Formulations.

Taxa Exposure Endpoint Used (μg a.i./L) 

(Test Substance) 

RQ values*

Based on Highest 

Spray Drift EEC1

Freshwater Fish Acute LC50 = 356 (Fontelis) 0.01 

Freshwater Fish Acute LC50 = 309 (Vertisan) 0.01 

Freshwater Invertebrates Acute EC50 = 59.6 (Fontelis) 0.046 

Freshwater Invertebrates Acute EC50 = 1215 (Vertisan) <0.01 * Bolded values indicate RQs that exceed the acute risk LOC (0.05 - listed species; or 0.5 - non-listed species). 1

 Based on the highest calculated spray drift EEC value (2.77 μg/L) using AgDRIFT - Using the maximum proposed 

single agriculture application rate of 0.39 lbs a.i./A (Fontelis - Brassica vegetables; succulent legumes; and root 

vegetables and leaves) 

4.1.1.2. Aquatic Plants 

As shown in Table 4.3, RQ values for listed non-vascular plants based on the Tier I Rice Model 

EEC for use on cranberries exceed the Agency’s LOC of 1.0. These LOC exceedances are 

characterized in the risk description using provisional models to refine the exposure estimated 

from the proposed use on cranberries. 
83

RQ values for all listed and non-listed vascular and non-vascular aquatic plants are less than the 

Agency’s risk to listed and non-listed aquatic plant LOCs of 1.0, based on the highest aquatic 

PE-calculated EEC, i.e., 45 μg/L, for the proposed use on succulent legumes. Therefore, the 

likelihood of adverse effects on aquatic plants associated with exposure to penthiopyrad TGAI 

and its Fontelis formulation is expected to be low with the exception of the proposed use on 

cranberries. 

Table 4.3. Aquatic Plant RQ Values for Exposure to Penthiopyrad.

Taxa

RQ 

Based on the Highest PE EEC 

of 45 μg/L for the Proposed 

Succulent Legume Use

RQ 

Based on the Tier I Rice 

Model EEC of 529 μg/L for 

the Proposed Cranberry Use

Aquatic vascular plants 

Non-Listed1

 <0.04 <0.44 

Listed2 0.04 0.44 

Aquatic non-vascular 

plants 

Non-Listed3

 0.04 0.44 

Listed4 0.11 1.3 * Bolded values indicate RQs that exceed the aquatic plant LOC (1.0) for listed and/or non-listed aquatic plants. 1

 based on L. gibba EC50>1205 μg/L 2

 based on L.gibba NOAEC=1205 μg/L 3

 based on S. costatum EC50=1200 μg/L 4

 based on S. costatum NOAEC=417 μg/L 

 4.1.2. Terrestrial Organisms 

4.1.2.1. Birds 

Acute RQs are not calculated for birds because definitive acute and sub-acute toxicity endpoints 

are not available. The bobwhite quail acute oral toxicity study and the mallard duck sub-acute 

study no treatment-related sublethal effects were observed at the highest test 

concentrations/doses tested. The estimated dose- and dietary-based EECs are all below the 

highest test concentration tested for the northern bobwhite acute oral and sub-acute dietary 

toxicity test, and the mallard sub-acute dietary toxicity test. 

Although there was a slight reduction in body weight gain during the exposure period for the 

sub-acute bobwhite quail study, based on the available toxicity data, it was determined that no 

treatment-related acute mortality or clinical signs of toxicity were observed in any of the acute 

avian studies at the highest concentrations/doses tested. However, in the zebra finch acute oral 

toxicity study, regurgitation was interpreted as a toxic effect. Further discussion of the predicted 

exposure values relative to the levels at which no mortality and reduction in body weight gain 

occurred is provided as part of the risk description in Section 4.2.2.1. 

As shown in Table 4.4, chronic avian RQ values based on the highest application rate for 

penthiopyrad of 0.95 lbs a.i./A range from 0.02 to 0.26 and are less than the Agency’s chronic 

risk LOC of 1.0. Given that chronic RQs based on the highest application rate are less than 

Agency’s LOC, RQs associated with agricultural use patterns at lower application rates would 

also be less than the chronic risk LOC. Therefore, risks to birds and the terrestrial-phase 
84

amphibians and reptiles for which they serve as surrogates associated with chronic exposure to 

penthiopyrad are expected to be minimal. 

Table 4.4. Avian RQs for Chronic Exposure to Penthiopyrad (Based on the maximum 

single application rate of 0.95 lbs a.i./A - for the proposed turf use)

DIETARY CATEGORY Chronic RQ 

Short Grass 0.26 

Tall Grass 0.12 

Broadleaf Plants/Small Insects 0.15 

Fruits/Pods/Seeds/Large Insects 0.02 

4.1.2.2. Mammals 

Similar to birds, acute RQs are also not calculated for mammals because definitive acute oral 

toxicity data are not available. Based on the available acute toxicity data, no mortality was 

observed in any of the mammalian studies at the highest concentrations/doses tested. Further 

discussion of the predicted exposure values relative to the levels at which no mortality was 

observed is provided as part of the risk description in Section 4.2.2.2.

 

Based on the highest application rate of 0.95 lbs a.i./A for proposed turf uses of penthiopyrad, 

RQs calculated for chronic mammalian exposure range from 0.04 to 0.59 for dietary exposure 

and 0.04 to 5.81 for dose-based RQs using upper-bound Kenaga values (see Table 4.5). The 

dietary-based RQs do not exceed the Agency’s chronic risk LOC (1.0). Dose-based chronic RQs 

exceed the Agency’s chronic risk LOC for nine body-size/dietary categories, based on the 

highest application rate of 0.95 lbs a.i./A for the proposed penthiopyrad turf use: 15g, 35g, and 

1000g mammals that eat short grass (RQs = 2.7 to 5.8), tall grass (RQs = 1.2 to 2.7), and 

broadleaf plants/small insects (RQs = 1.5 to 3.3). In addition, dose-based RQs using the lowest 

application rate 0.21 lbs a.i./A (for all cucurbits proposed uses) exceed chronic risk LOCs for 

two body-size/dietary categories: 15g and 35g mammals that eat short grass (RQs = 1.2 to 1.4). 

These results indicate that all proposed use patterns of penthiopyrad exceed chronic risk LOCs 

for mammals for a number of body-size/dietary categories. Further discussion of the chronic 

mammalian exposure and risk associated is provided as part of the risk description in Section 

4.2.2.2. 
85

Table 4.5. Mammalian RQs for Chronic Exposure to Penthiopyrad using the upper Upper 

Bound Kenaga values1

Dietary 

Category 

Body 

Size 

Proposed Turf Use 

(0.95 lbs a.i./A) 

(maximum non-agricultural use rate)

Proposed Cucurbits Use 

(0.21 lbs a.i./A) 

(minimum agricultural use rate)

Dietary-based 

Chronic RQ 

Dose-based 

Chronic RQ 

Dose-based 

Chronic RQ 

Short Grass 

15 g 

0.59 

5.8 1.4 

35 g 5.0 1.2 

1,000 g 2.7 0.64 

Tall Grass 

15 g 

0.27 

2.7 0.64 

35 g 2.3 0.54 

1,000 g 1.2 0.29 

Broadleaf 

Plants/Small 

Insects 

15 g 

0.33 

3.3 0.78 

35 g 2.8 0.67 

1,000 g 1.5 0.36 

Fruits/Pods/Large 

Insects 

15 g 

0.04 

0.36 0.09 

35 g 0.31 0.07 

1,000 g 0.17 0.04 

Granivore 

(Seeds) 

15 g 

N/A 

0.08 0.02 

35 g 0.07 0.02 

1,000 g 0.04 0.01 

Bolded numbers indicate RQs that exceed the Agency’s chronic risk LOC for mammals (1.0). 1

 The body weight of chronic mammals was adjusted to 135g (body weight of test organisms during the study). 

4.1.2.3. Terrestrial Invertebrates 

Penthiopyrad is classified as ‘practically non-toxic’ to honey bees on an acute contact and oral 

exposure basis, based on available data for the TGAI and the Fontelis, the Vertisan formulated 

products. However, the Treoris formulated product is moderately toxic to honey bees on an 

acute contact basis. Additional characterization of the potential effects of penthiopyrad on 

terrestrial invertebrates, and beneficial insects, including consideration of non-guideline 

laboratory studies with non-target arthropods, is provided as part of the risk description in 

Section 4.2.2.2. 

4.1.2.4. Non-target Terrestrial and Semi-Aquatic Plants 

Potential effects to riparian and upland vegetation are assessed from terrestrial plant seedling 

emergence and vegetative vigor data as a screen. Based on the results of the submitted Tier I 

terrestrial non-target plant studies for the suspension concentrate Fontelis 20% penthiopyrad a.i.; 

see Table 3.30), adverse effects, (14% inhibition of seedling emergence and survival of 

ryegrass,12% inhibition on growth (dry weight) of wheat, and 20% inhibition on growth (dry 

weight) in tomato, and 20% inhibition on growth (dry weight) of wheat and 8% inhibition on 

growth (dry weight) of soybean), were seen for both monocot and dicot species in both the 

seedling emergence and vegetative vigor toxicity tests. There were no adverse effects on seedling 

condition, survival, dry weight and height of the remaining terrestrial plant species tested, and 

overall, there were no species that had an inhibition of 25% or greater for any endpoint that was 
86

tested. Therefore, based on these results the EC25>1.39 lbs a.i./A for both seedling emergence 

and vegetative vigor studies. However, it was noted that definitive NOAEC’s were not obtained 

for ryegrass, wheat, and tomato (seedling emergence study), and wheat and soybean (vegetative 

vigor study), as these species exhibited treatment related, statistically significant (p<0.05), 

reductions at the limit concentration relative to the negative control. Although Tier II studies are 

not required as no effects were greater than 25%, Tier II studies would reduce the uncertainty 

regarding Endangered Species assessments. Without a valid/definitive NOAEC value, risk to 

listed plant species would be assumed to an undefined area around the application site. However, 

the available data indicate that the other six tested plants, did not exhibit adverse effects in the 

seedling emergence or vegetative vigor tests. 

With respect to the monocots ryegrass and wheat, and the dicots tomato and soybean, due to the 

presence of effects at the single application rate of 1.39 lbs a.i./A, without additional data an 

assumption of risk to listed plants will be made. However, there were less than 25% effects 

observed at a level above the highest proposed application rate, risks to non-listed plants and 

indirect effects to listed animals with no obligate relationships with plants can be discounted. 

Risk to listed plants and animals with obligate relationships with plants cannot be discounted. 

Further discussion the uncertainty due to the presence of effects is included in the risk 

description for terrestrial plants and in Section 4.2.2.3. 

 4.2. Risk Description 

Penthiopyrad is characterized as a non-volatile, lipophilic compound that is moderately mobile in 

soil. Depending on soil type, the compound may move to ground water slowly via leaching and 

may move to surface water bodies via spray drift and runoff of dissolved or sorbed residues. 

Penthiopyrad is expected to degrade mainly via indirect photolysis in soil; however, the 

compound may persist in many compartments of the environment, dissipating in shaded and 

aquatic areas by slow aerobic biodegradation and attenuated leaching; under anaerobic 

conditions, the compound is likely to persist. Given the potential mobility and persistence of the 

compound under certain environmental conditions, non-target organisms have the potential to be 

exposed. 

Based on the effects assessment, penthiopyrad is classified as moderately to highly toxic to 

freshwater fish and invertebrates and to aquatic-phase amphibian (for which fish serve as 

surrogates) and is moderately toxi to estuarine/marine fish and invertebrates on an acute 

exposure basis. For terrestrial species, the compound is practically non-toxic to mammals, birds 

(and to reptiles and terrestrial-phase amphibians for which birds serve as surrogates), and to 

terrestrial invertebrates on an acute exposure basis. Chronic exposure to penthiopyrad resulted in 

reductions in survival and growth in fish; reduced survival, growth and reproduction in aquatic 

invertebrates, reduction in eggs set and laid in birds, and reduced growth in mammals. 

 

The results of this baseline-level risk assessment indicate that the proposed uses of penthiopyrad 

(except use on canola) have the potential for direct adverse acute effects on listed freshwater fish 

(a surrogate for aquatic-phase amphibians). Acute effects on listed estuarine/marine fish and 

invertebrates (via spray drift from the Fontelis formulation) cannot be precluded. The proposed 

use on cranberries results in additional potential effects, including potential direct adverse acute 
87

effects on listed and non-listed freshwater fish (a surrogate for aquatic-phase amphibians); acute 

effects on listed freshwater invertebrates, estuarine/marine fish and invertebrates; chronic effects 

to freshwater fish and estuarine/marine invertebrates7

; and acute effects on listed 

estuarine/marine fish and invertebrates (via spray drift from Fontelis formulated product). All 

proposed uses of penthiopyrad result in potential direct adverse chronic effects on listed and nonlisted mammals. In addition, due to effects seen at the single application rate for both terrestrial 

monocot and dicot plant species in the seedling emergence and vegetative vigor toxicity tests, 

risk to terrestrial plants and animals with obligate relationships with plants are assumed. Based 

on the results of the baseline-level assessment, the risk hypothesis [...the proposed penthiopyrad 

uses have the potential to reduce survival, reproduction, and/or growth in terrestrial and aquatic 

organisms] is supported. These results are based on all application rates for the proposed 

penthiopyrad uses. Although direct adverse effects to birds, terrestrial-phase amphibians, and 

reptiles, from penthiopyrad use are not expected, indirect effects to these taxa are possible, given 

the effects on aquatic animals and terrestrial mammals could indirectly impact the terrestrial 

organisms that feed on these species. 

4.2.1. Risks to Aquatic Animals 

Acute RQs for freshwater fish exceed the Agency’s listed species LOC (0.05), for all proposed 

use patterns of penthiopyrad except use on canola. However, for proposed uses other than 

cranberry, acute and chronic RQs for estuarine/marine fish, freshwater invertebrates, 

estuarine/marine invertebrates, and sediment-dwelling organisms do not exceed the Agency’s 

LOCs, based on the highest PE-calculated surface water EECs (associated with the proposed use 

on succulent legumes). The toxicological level of concern for listed freshwater fish is 14.5 μg 

a.i./L. In order to result in no LOC exceedances for listed freshwater fish (i.e., result in an EEC 

<14.5 μg/L), the application rate for the proposed use on succulent legumes would have to be 

reduced to one treatment per year at 0.29 lbs a.i./A. The application rate for the proposed use on 

sugarbeets (the use with the smallest LOC exceedance) would have to be reduced to 2 treatments 

per year at 0.27 lbs a.i./A or the proposed application rate of 0.39 lbs a.i./A could be limited to 

one treatment per year in order to result in no LOC exceedances. 

For use on cranberries, an acute RQ exceeded the LOC for non-listed freshwater fish, acute risk 

LOCs were exceeded for listed aquatic animals, and chronic risk LOCs were exceeded for 

aquatic animals (other than sediment-dwelling organisms). Additional exposure modeling was 

conducted with provisional flooded agriculture models (Tier I Cranberry Model and PFAM) in 

order to characterize these potential risks because the Tier I Rice Model is a poor estimator of 

exposure resulting from use on cranberries (Table 4.6). The provisional cranberry models 

support the risk conclusions based on the Tier I Rice Model with the exception that the chronic 

risk LOC is not exceeded for estuarine/marine fish and freshwater invertebrates. Therefore, 

chronic risk to estuarine/marine fish and freshwater invertebrates is not expected to be of 

concern. The acute risk LOC remains exceeded for non-listed freshwater fish, acute risk LOCs 

remain exceeded for listed aquatic animals, and chronic risk LOCs remain exceeded for 

 

7

 Based on the refined cranberry model calculated EEC values, and derived acute and chronic RQs. The Tier I rice 

model calculated EEC value results in potential direct adverse acute and chronic effects to all aquatic organisms, as 

well as aquatic non-vascular plants. 
88

freshwater fish and estuarine/marine invertebrates. Estuarine/marine invertebrates (EC50 = 1200 

μg a.i./L) are roughly twice as sensitive to penthiopyrad on an acute exposure basis than 

freshwater invertebrates (EC50 = 2531 μg a.i./L). For the cranberry use, using the 21-day EECs 

estimated from the provisional flooded agriculture models (Tier I Cranberry Model and PFAM; 

245 and 293 μg a.i./L, respectively) and an LOC of 1, the Agency’s chronic risk LOC is 

exceeded based on the estimated ACR for estuarine/marine invertebrates. Therefore, chronic 

risk based on the cranberry use still cannot be precluded for estuarine/marine invertebrates based 

on this uncertainity. In order to result in no LOC exceedances for listed aquatic organisms (i.e., 

result in an EEC <14.5 μg/L) using the provisional Tier I Cranberry Model, the application rate 

for the proposed use on cranberries would have to be reduced to one treatment per year at 0.055 

lbs a.i./A. 

Table 4.6. Provisional Aquatic Animal RQ Values for Exposure to Penthiopyrad TGAI 

Resulting from the Proposed Use on Cranberries.*

Taxa Exposure Endpoint Used 

(μg a.i./L) 

TICM1

RQ values2

PFAM 

RQ values3

Freshwater Fish Acutea LC50 = 290 0.86 1.0 

Estuarine/Marine Fish Acutea LC50 = 1381 0.18 0.22 

Freshwater Invertebrates Acutea EC50 = 2531 0.10 0.12 

Estuarine/Marine Invertebrates Acutea EC50 = 1200 0.21 0.25 

Freshwater Fish Chronica NOAEC = 100 2.3 2.9 

Estuarine/Marine Fish Chronica NOAEC = 476 0.49 0.61 

Freshwater Invertebrates Chronica NOAEC = 471 0.52 0.62 

Estuarine/Marine Invertebrates Chronica NOAEC = 223 1.1 1.3 * Bolded values exceed an LOC. 1

 TICM means “Tier I Cranberry Model”. 

2

 The EECs for cranberries from the Tier I Cranberry Model (peak=250 μg/L, 21-d mean=245 μg/L, 60-d mean=233 

μg/L) were used to calculate RQ values for characterization. 3

 The EECs for cranberries from PFAM (peak=298 μg/L, 21-d mean=293 μg/L, 60-d mean=289 μg/L) were used to 

calculate RQ values for characterization. 

There were no acute risk LOC exceedances for freshwater fish or invertebrates for the Fontelis or 

the Vertisan formulations. Acute RQs were below the Agency’s risk to listed species LOC 

(0.05), based on spray drift EECs associated with the highest proposed agriculture use 

application rate of 0.39 lbs a.i./A, only (uses under the Fontelis label at 0.39 lbs a.i./A are 

Brassica vegetables; succulent legumes; and root vegetables and leaves and uses under the 

Vertisan label at 0.39 lbs a.i./A are soybeans, sugarbeets, and sunflowers) (Table 4.2). 

However, acceptable estuarine/marine fish and invertebrate toxicity data are not available for 

either the Fontelis or Vertisan formulations. Estuarine/marine fish appear to be less sensitive to 

the Fontelis formulation compared with freshwater fish; however, due to the presence of 

precipitate and the lack of centrifugation of the test samples (they instead were mixed with a topdown mixer), there is a concern that samples do not represent only soluble penthiopyrad 

concentrations. There is the potential for exposure to the penthiopyrad Fontelis formulation due 

to the use on cranberries, therefore, to alleviate uncertainty a new toxicity study is recommended. 

Estuarine/marine invertebrates are of particular concern as they were more toxic than freshwater 
89

invertebrates to the penthiopyrad TGAI. In addition, the Fontelis formulation was approximately 

42 times more toxic to freshwater invertebrates than the penthiopyrad technical (TGAI). 

Therefore, based on these results, the Fontelis formulation toxicity to estuarine/marine 

invertebrates is not known, and could potentially be more toxic than the freshwater invertebrates 

as was the case with the TGAI. 

Therefore, based on the available information, there is a potential for adverse effects on listed 

freshwater fish and aquatic-phase amphibians due to acute exposure of penthiopyrad for all 

proposed uses except canola (including use on cranberries). Specifically for the proposed use on 

cranberries (utilizing provisionally refined cranberry models), there is a potential for adverse 

effects on non-listed freshwater fish and listed freshwater fish and invertebrates, and 

estuarine/marine fish and invertebrates based on acute exposure to penthiopyrad, and a potential 

for adverse effects on freshwater fish and estuarine/marine invertebrates based on chronic 

exposure to penthiopyrad. In addition, there is the potential for exposure to the penthiopyrad 

Fontelis formulation due to the use on cranberries. Therefore, without estuarine/marine fish or 

invertebrate toxicity data; risk to estuarine/marine organisms exposed to the Fontelis formulation 

via spray drift is presumed. 

 4.2.1. Risks to Aquatic Plants 

 

Penthiopyrad is not expected to directly impact the growth of non-listed and listed vascular and 

non-vascular aquatic plants. This conclusion is based on a lack of LOC exceedances by RQs for 

the highest peak aquatic PE-calculated EEC for penthiopyrad proposed use patterns other than 

cranberries. 

For use on cranberries, the listed species LOC was exceeded for non-vascular plants (RQ=1.3). 

However, additional exposure modeling was conducted with provisional flooded agriculture 

models (Tier I Cranberry Model and PFAM) that are expected to be superior estimators of 

exposure resulting from use on cranberries. These models indicate that the listed species LOC is 

not exceeded for non-vascular plants (RQ range 0.60-0.71). Therefore, penthiopyrad is not 

expected to directly impact any aquatic plants. 

Table 4.7. Provisional Aquatic Plant RQ Values for Exposure to Penthiopyrad TGAI 

Resulting from the Proposed Use on Cranberries.*

Taxa Endpoint Used TICM1

RQ values2

PFAM 

RQ values3

Aquatic non-vascular 

plants (Marine Diatom) 

Non-Listed S. costatum EC50=1200 μg/L 0.21 0.25 

Listed S. costatum NOAEC=417 μg/L 0.60 0.71 * Bolded values indicate RQs that exceed the aquatic plant LOC (1.0) for listed and/or non-listed aquatic plants. 1

 TICM means “Tier I Cranberry Model”. 

2

 The EECs for cranberries from the Tier I Cranberry Model (peak=250 μg/L) was used to calculate RQ values for 

characterization. 

3

 The EECs for cranberries from PFAM (peak=298 μg/L) was used to calculate RQ values for characterization. 
90

 4.2.2. Risks to Terrestrial Organisms 

4.2.2.1. Birds, Terrestrial-Phase Amphibians and Reptiles 

The avian chronic risk LOC is not exceeded for any of the proposed penthiopyrad use patterns, 

indicating that the likelihood of adverse effects on birds, terrestrial-phase amphibians, and 

reptiles due to chronic exposure is low. 

Because there was no mortality at the highest treatment levels tested in the submitted acute oral 

and sub-acute dietary avian studies, standard RQs values for acute and sub-acute exposure were 

not calculated in the Risk Estimation section of this assessment. However, there was a reduction 

in body weight gain during the exposure period for the bobwhite quail sub-acute dietary study at 

the highest test concentration of 5,790 mg/kg-diet with no effect reported at 3,320 mg a.i./kgdiet. In order to gain a better understanding of how the EECs for the maximum proposed 

penthiopyrad application rate relate to the toxicity data currently available for birds, T-REX was 

used to calculate EECs and the EECs compared to the highest level tested without any observed 

effect (i.e., 2,218 mg a.i./kg-bw in the acute oral study; 3,320 mg a.i./kg-diet in the subacute 

avian dietary study; and 1520 mg a.i./kg-diet in the chronic avian study). The resulting dietarybased acute EECs for all size and dietary classes, based on the upper-bound Kenaga values and 

the maximum proposed non-argicultural use (turf) ranged from 25 to 401 ppm (Table 3.14), and 

the dose-based acute EECs for all size and dietary classes, based on the upper-bound Kenaga 

values and the maximum proposed non-argicultural use (turf) ranged from 1.6 to 456 mg/kg-bw 

(Table 3.14), which are all well below the highest levels tested without effects. Therefore, the 

likelihood of adverse effects on growth (weight gain) land direct effects on birds (and to 

terrestrial-phase amphibian and reptiles for which birds serve as surrogates) from acute, subacute, or chronic exposure to penthiopyrad is expected to be low. However, given the potential 

for effects on freshwater fish, aquatic-phase amphibians, plants, and terrestrial mammals 

associated with the proposed uses of penthiopyrad, indirect effects to birds are possible. 

As previously discussed in Section 3.3.2.1, avian acute oral data are now required for passerine 

species, as well as either waterfowl or upland game species. Although, no mortalities were 

observed in any test concentration for the duration of the zebra finch acute oral toxicity study, 

regurgitation was observed at every level and this effect is assumed to be a toxic response to the 

chemical exposure. An effect dose (ED50) was calculated using regurgitation as the effect, as a 

LD50 (lethal dose) could not be determined from the doses tested. The estimated dose-based 

EECs for the maximum application for the proposed turf use are greater than the estimated ED50

value for passerine species (456.46 for birds consuming short grass vs. ED50 value of 335 mg 

a.i./kg-bw). Therefore, at the current maximum proposed application rate there is the potential 

for direct risk to passerine species. If the ED50 dose was used to calculate a ratio of EEC/ED50

values based on the toxic effect of regurgitation, the dietary-based acute ratio of EEC/ED50 value 

exceeds the Agency’s acute risk LOC (0.05) for one body size/dietary category: 20g birds that 

eat short grass (ratio of EEC/ED50 = 0.07), based on the highest application rate of 0.95 lbs a.i./A 

for the proposed penthiopyrad turf use. In addition, the dose-based acute ratio of EEC/ED50

values also exceed the Agency’s acute risk LOC (0.05) for four body-size/dietary categories for 

small birds (20g), based on the highest application rate of 0.95 lbs a.i./A for the proposed 
91

penthiopyrad turf use: 20g birds that eat short grass (ratio of EEC/ED50 = 1.3), tall grass (ratio of 

EEC/ED50 = 0.59), broadleaf plants/small insects (ratio of EEC/ED50 = 0.72), and 

fruits/pods/seeds/large insects (ratio of EEC/ED50 = 0.08). 

However at the lower proposed application rates ranging from 0.21 to 0.31 lbs a.i./A the 

resulting estimated dose-based EECs range from 1001 to 149 mg a.i /kg bw for birds consuming 

short grass, respectively. The estimated EEC values for these proposed application rates are less 

than the ED50, and the LOAEL (156 mg a.i./kg bw), but still greater than the NOAEL of 93 mg 

a.i./kg bw. The one exception is for the maximum proposed application rate for agricultural uses 

(0.39 lbs a.i./A), the resulting short grass dose-based EEC value is 187 mg a.i./kg bw, which is 

greater than the LOAEL value, indicating the potential for direct risk to passerine species exists. 

The dose-based acute ratio of EEC/ED50 values calculated using the effect dose (toxic effect of 

regurgitation) also exceed the Agency’s acute risk LOC (0.05) for three body-size/dietary 

categories for small birds (20g), based on the highest agricultural application rate of 0.39 lbs 

a.i./A: 20g birds that eat short grass (ratio of EEC/ED50 = 0.56), tall grass (ratio of EEC/ED50 = 

0.26), andbroadleaf plants/small insects (ratio of EEC/ED50 = 0.31). Therefore, at the current 

proposed application rates of 0.95 (maximum non-agricultural) and 0.39 lbs a.i./A (maximum 

agricultural) there is the potential for direct sublethal effects to passerine species. 

There is uncertainty using an effect dose based on a toxic effect (i.e., regurgitation) when a 

definitive LD50 cannot be calculated. Therefore, to further characterize the acute avian risk 

associated with penthiopyrad applicaition, the potential for passerine effects was characterized 

further using dose-based exposure values and available data for the other tested avian species 

(bobwhite quail and mallard duck), was also completed. As shown in Table 3.10, dose-based 

exposures for small (20-g) birds exposed to the maximum application rate for penthiopyrad of 

0.95 lbs a.i./A range from 6.34 to 456 mg a.i./kg-bw. Assuming that passerines are of equal 

sensitivity to acute dose-based exposures of penthiopyrad as the bobwhite quail, risks would not 

be expected because no avian mortalities were observed at the maximum dose level of 2,218 mg 

a.i./kg-bw. Given that no mortality was observed at the highest treatment level in either 

submitted acute oral study for the bobwhite quail, it is unclear how much more sensitive 

passerine species would have to be as compared with upland game species to exceed acute risk 

LOCs. However, the LD50 for passerine species would have to be at least the highest treatment 

level tested for upland game species to exceed the acute avian acute risk to listed species LOC. 

Submittal of an acceptable acute oral passerine toxicity study in accordance with OPPTS 

850.21008

 would reduce the uncertainty associated with risks to passerines. However, because 

of an apparent treatment-related regurgitation occurred in the submitted passerine study, a 

subacute dietary toxicity study using the passerine species and the penthiopyrad TGAI is more 

appropriate to assess risk to non-target passerine bird species. Without additional data, direct 

risk to passerine species is presumed in the absence of a definitive LD50, due to the presence of 

adverse effects (regurgitation) in all treatment concentrations. 

 

8

 USEPA 1996. 

http://www.epa.gov/ocspp/pubs/frs/publications/OPPTS_Harmonized/850_Ecological_Effects_Test_Guidelines/Dra

fts/850-2100.pdf 
92

In addition, the potential for indirect effects to birds from penthiopyrad use cannot be discounted, 

due to the risk to freshwater fish, aquatic-phase amphibians, freshwater invertebrates, plants, and 

terrestrial mammals. 

KABAM-estimated RQs based on dose-based or dietary-based exposures of birds to 

penthiopyrad through consumption of contaminated aquatic prey are listed in Table 4.8. Acute 

and chronic RQs are less than the Agency’s levels of concern. Therefore, risks to birds and the 

terrestrial-phase amphibians and reptiles for which they serve as surrogates associated with acute 

and chronic exposure to penthiopyrad are expected to be minimal. 

Table 4.8. KABAM RQs for birds ingesting contaminated aquatic prey. 

Wildlife species Acute Chronic 

Dose-based Dietary-based Dietary-based 

sandpipers 0.034 0.009 0.036 

cranes 0.002 0.008 0.031 

rails 0.017 0.010 0.039 

herons 0.002 0.008 0.031 

small osprey 0.002 0.004 0.015 

white pelican 0.000 0.002 0.007 

4.2.2.2. Mammals 

Acute RQs were not derived for mammals in the Risk Estimation section of this assessment 

because no mortality was observed at the highest treatment level in the acute oral mammalian 

studies for penthiopyrad. In order to gain a better understanding of how the EECs for the 

maximum proposed penthiopyrad application rate relate to the toxicity data currently available 

for mammals, T-REX was used to calculate EECs and the EECs compared to the highest level 

tested without any observed effect (i.e., 2,000 mg a.i/kg in the acute oral study). The resulting 

dose-based acute EECs for all size and dietary classes, based on the upper-bound Kenaga values 

and the maximum proposed non-argicultural use (turf) ranged from 25 to 401 ppm (Table 3.14), 

and the dose-based acute EECs for all size and dietary classes, based on the upper-bound Kenaga 

values and the maximum proposed non-argicultural use (turf) ranged from 0.85 to 382 mg/kg-bw 

(Table 3.14), which are all well below the highest levels tested without effects. Therefore, 

likelihood of direct adverse effects to mammals from acute exposure to penthiopyrad is 

considered to be low. However, given the potential for effects on freshwater fish, aquatic-phase 

amphibians, plants, and terrestrial mammals associated with the proposed uses of penthiopyrad, 

indirect effects to mammals are possible. 

Based on the highest application rate of 0.95 lbs a.i./A for proposed turf uses of penthiopyrad, 

the Agency’s chronic risk LOC is exceeded for the following nine body size/dietary categories: 

15-g, 35-g, and 1000-g mammals eating short grass, tall grass, and broadleaf plants/small insects 

(RQs that exceed the LOC range from 1.5 to 5.8). Chronic risk LOC exceedances were based on 

a reproductive NOAEL of 38 mg a.i./kg bw/day (680 mg/kg-diet). For parents reduced body 

weight gain in F1 adult males, an increased liver weight in P and F1 adult females and increased 

relative adrenal weight with increased incidence of cortical hypertrophy in F1 females, were 

observed at a treatment level of 54 mg/kg/day (1000 mg/kg-diet). For offspring reduced body 
93

weight and body weight gain, delay in preputial separation, and a decrease in absolute thymus 

weights were observed at a treatment level of 278 mg/kg/day (5000 mg/kg-diet). No dietarybased RQs exceed the Agency’s chronic risk LOC. 

Based on the lowest proposed application rate of 0.21 lbs a.i./A (cucurbits proposed use) for 

penthiopyrad, the Agency’s chronic risk LOC is exceeded for the following two body 

size/dietary categories: 15-g and 35-g mammals that eat short grass (RQs that exceed the LOC 

range from 1.2 to 1.4. The results for the highest and lowest application rates indicate that all 

proposed (non-agricultural and agricultural) use patterns of penthiopyrad exceed the chronic risk 

LOC for mammals in a number of body-size/dietary categories. 

To further characterize chronic risk to mammals the chronic dose-based RQs were calculated 

based on the mean Kenaga residue values and the highest application rate of 0.95 lbs a.i./A for 

the proposed use on turf. The resulting chronic dose-based RQ values ranged from 0.02 to 2.1 

(see Table 4.9 below). The Agency’s chronic risk LOC is exceeded for the following three body 

size/dietary categories: 15g and 35g mammals that consume short grass (RQs = 1.8 and 2.1), and 

15g mammals that consume broadleaf plants/small insects (RQ = 1.1). The only other proposed 

use that also results in the Agency’s chronic risk LOC exceedance based on chronic dose-based 

RQs (based on the mean Kenga residue values) is the proposed landscape ornamental use. The 

proposed landscape ornamental use is the only use that does not have a restriction to two 

consecutive applications on the label, therefore, based on the annual maximum application rate 

of 3.0 lbs a.i./A and a maximum single application rate of 0.25 lbs a.i./A, penthiopyrad can be 

applied up to 12 times annually for the proposed landscape ornamental use. The Agency’s 

chronic risk LOC is exceeded for the following three body size/dietary categories: 15g and 35g 

mammals that consume short grass (RQs = 1.6 and 1.9), and 15g mammals that consume 

broadleaf plants/small insects (RQ = 1.0). One note for consideration is that the reliance on 

mean acute numbers implies that the EECs would be higher 50% of the time. 

Table 4.9. Mammalian RQs for Chronic Exposure to Penthiopyrad using the mean 

Kenaga residue values1

Dietary 

Category 

Body 

Size 

Proposed Turf Use 

(0.95 lbs a.i./A) 

(maximum non-agricultural use) 

Proposed Landscape Ornamental Use2

(0.25 lbs a.i./A) 

(maximum single application rate) 

3.0 lbs a.i./A 

(maximum annual application rate) 

Dose-based Chronic RQ* Dose-based Chronic RQ* 

Short Grass 15g 2.1 1.9 

35g 1.8 1.6 

1,000g 0.94 0.88 

Tall Grass 15g 0.87 0.82 

35g 0.74 0.70 

1,000g 0.40 0.37 

Broadleaf 

Plants/Small 

Insects 

15g 1.1 1.0 

35g 0.93 0.87 

1,000g 0.50 0.47 
94

Dietary 

Category 

Body 

Size 

Proposed Turf Use 

(0.95 lbs a.i./A) 

(maximum non-agricultural use) 

Proposed Landscape Ornamental Use2

(0.25 lbs a.i./A) 

(maximum single application rate) 

3.0 lbs a.i./A 

(maximum annual application rate) 

Dose-based Chronic RQ* Dose-based Chronic RQ* 

Fruits/Pods/ 

Large Insects 

15g 0.17 0.16 

35g 0.14 0.14 

1,000g 0.08 0.07 

Granivore 

(Seeds) 

15g 0.04 0.04 

35g 0.03 0.03 

1,000g 0.02 0.02 

* Bolded numbers indicate RQs that exceed the Agency’s chronic risk LOC for mammals (1.0) 1

 The body weight of chronic mammals was adjusted to 135g (body weight of test organisms during the study). 

2

 The proposed landscape ornamental use is the only use that does not have a restriction to two consecutive 

applications on the label, therefore, based on the annual maximum application rate of 3.0 lbs a.i./A and a maximum 

single application rate of 0.25 lbs a.i./A, penthiopyrad can be applied up to 12 times annually for the proposed 

landscape ornamental use. 

An additional characterization used the lowest-observed adverse effect concentration (LOAEC) 

(1000 mg/kg-diet; 54 mg/kg/day) to bound the chronic risk potential to mammals and determined 

if the lowest concentration in the study that resulted in effects also would result in chronic risk to 

mammals. Based on the analysis, the Agency’s chronic risk LOC for mammals is still exceeded 

on a dose-basis for some body size/dietary categories for all uses except the cucurbit use (lowest 

application rate of 0.21 lbs a.i./A), using the upper-bound Kenaga values. The dose-based EEC 

values for the proposed turf use range from 0.85 for granivores (seeds) dietary category to 382 

for the short grass dietary category, and the dose-based EEC values for the proposed cucurbit use 

range from 0.20 for granivores (seeds) dietary category to 92 for the short grass dietary category. 

The resulting ratio of EEC/LOAEC values range from 0.03 to 4.1 for the proposed turf use, and 

0.1 to 0.98 for the proposed cucurbit use. The lowest application rate where there are still 

chronic mammalian risk LOC exceedances is the proposed landscape ornamental use (0.25 lbs 

a.i./A). The proposed landscape ornamental use is the only use that does not have a restriction to 

two consecutive applications on the label, therefore, based on the annual maximum application 

rate of 3.0 lbs a.i./A and a maximum single application rate of 0.25 lbs a.i./A, penthiopyrad can 

be applied up to 12 times annually for the proposed landscape ornamental use. The resulting 

ratio of EEC/LOAEC values range from 0.02 to 3.8 for the proposed landscape ornamental use. 

These additional characterizations further demonstrate the potential chronic risk to mammals 

based on all proposed use patterns of penthiopyrad. Therefore, all proposed uses (nonagricultural and agricultural) of penthiopyrad pose potential chronic risks to listed and non-listed 

mammals from penthiopyrad at application rates ≥0.21 lbs a.i./A. 

In addition, the potential for indirect effects to terrestrial mammals from penthiopyrad use cannot 

be discounted, due to the risk to freshwater fish, aquatic-phase amphibians, freshwater 

invertebrates, plants, and terrestrial mammals. 
95

KABAM-estimated RQs based on dose-based or dietary-based exposures of mammals to 

penthiopyrad through consumption of contaminated aquatic prey are listed in Table 4.10. Dosebased chronic RQs for two of six size classes of mammal (shrews and moles) exceeded the 

Agency’s chronic risk level of concern (1.0). Acute RQs and dietary-based chronic RQs for all 

size classes of mammal were less than the Agency’s levels of concern. These results indicate 

that the maximum use patterns of penthiopyrad may exceed chronic risk LOCs for some 

mammals (such as shrews and moles) that ingest benthic invertebrates. LOCs were not exceeded 

for mammals (minks and otters) that do not consume benthic invertebrates because these 

mammals consume fish instead and penthiopyrad is readily metabolized in fish (according to the 

submitted fish BCF study, MRID 47614995). Study-derived metabolism rates in fish cannot be 

extrapolated to metabolism rates in benthic invertebrates since the latter often metabolize 

compounds slower than fish. Therefore, there is concern for bioaccumulation of penthiopyrad in 

benthic invertebrates. Concern for bioaccumulation in mammals centers on this uncertainty in 

bioaccumulation in benthic invertebrates. An oyster BCF study could reduce this uncertainty. 

Table 4.10. KABAM RQs for mammals ingesting contaminated aquatic prey. 

Wildlife species Acute Chronic1

Dose-based Dose-based Dietary-based 

fog/water shrew 0.010 2.0 0.36 

rice rat/star-nosed mole 0.009 1.8 0.27 

small mink 0.004 0.71 0.11 

large mink 0.004 0.79 0.11 

small river otter 0.004 0.85 0.11 

large river otter 0.002 0.45 0.056 1 Bolded values exceed the chronic risk LOC (1.0). 

The proposed penthiopyrad uses on landscape ornamentals, sugarbeets, and canola do not result 

in LOC exceedances for any mammalian size class. More specifically, if the water column (20.5 

μg/L) and pore water (20.0 μg/L) 1-in-10-year 4-day mean EECs for use on landscape 

ornamentals are input into KABAM, then there are no LOC exceedances. However, for the use 

with the next highest EECs, tree nuts, the chronic LOC is exceeded for the smallest mammal size 

class (shrew). This indicates that proposed uses of penthiopyrad other than landscape 

ornamentals, sugarbeets, and canola may result in chronic LOC exceedances for mammals that 

consume benthic invertebrates. If the proposed use on succulent legumes is reduced to one 

treatment per year at 0.39 lbs a.i./A, then the chronic LOC is not exceeded for any size class of 

mammals. 

The applicant has informally claimed uncertainty in the submitted log KOW value (4.62) used in 

this assessment [undated letter to the United Kingdom’s Chemicals Regulation Directorate 

(CRD)]. The shorter than expected time to steady state in the submitted fish BCF study is 

additional evidence that the log KOW of penthiopyrad may be lower than 4.62. On the other 

hand, KOWWIN v1.67 estimates a log KOW of 4.95 for penthiopyrad. The applicant has not 

submitted information that refutes the log KOW value of 4.62. If both the currently submitted 

KOW study is refuted and an acceptable KOW study is submitted with a lower value, then 

KABAM risk estimates may be reduced. Using the 1-in-10-year 4-day mean EECs from use on 
96

succulent legumes that were used to produce RQs in Table 4.10, the log KOW of penthiopyrad 

would have to be 4.31 or less in order to result in no risk exceedances. 

4.2.2.3. Terrestrial Invertebrates 

Honeybees 

Although penthiopyrad TGAI and the Fontelis formulation were found not to adversely affect 

honeybees, toxic effects (although classified as not being dose-dependent) were observed in the 

Fontelis formulation study (MRID 47615237). The toxic effects observed included cramps 

(contracting abdomen or entire body), moribound (bees cannot walk and show only very feeble 

movements of legs and antennae, only weak response to stimulation (e.g., light, air movement), 

bees may recover but usually die, affected (bees still upright and attempting to walk but show 

signs of reduced co-ordination), and apathy (bees showing only slow or delayed reactions to 

stimulation (e.g., light, air movement); bees are either sitting motionless in the cage or 

staggering). The presence of sublethal effects using the Fontelis formulation, indicate that there 

could still be toxic sublethal effects to bees that could negatively impact the hive and/or colony. 

The Vertisan formulated product resulted in definitive toxicity values for honey bees, and it was 

the only formulation that did for honeybees. In addition to lethal effects, other toxic effects that 

were observed in the Vertisan formulation study (MRID 47615337) included the sublethal 

effects of lying on their back, apathy (bees showing only slow or delayed reactions to stimulation 

(e.g., light, air movement); bees are either sitting motionless in the cage or staggering), and 

lethargy (bees walking slowly dragging their legs). The presence of both lethal and sublethal 

effects using the Vertisan formulation, indicate that toxic effects to honey bees could negatively 

impact the hive and/or colony. 

The co-formulated product Treoris also exhibited lethal and sublethal toxic effects in the acute 

contact study (MRID 47737326), the sublethal effect observed was lethargy (bees walking 

slowly dragging their legs). It is important to highlight that chlorothalonil has been associated 

with numerous bee incidents, and that chlorothalonil has been documented inside the hive, 

within bees, and it has also been found sequestered in bee pollen (Mullin et al., 2010). These 

incidents and available data demonstrate that chlorothalonil is making its way back to the colony. 

Although, the available toxicity data indicates that the penthiopyrad technical does not result in 

effects to adult bees, the effects to bees in relation to the association of penthiopyrad and 

chlorothalonil in the co-formulated product, the Treoris formulation may increase the toxicity of 

penthiopyrad and chlorothalonil to bees. 

Based on the submitted toxicity data for the formulations of penthiopyrad (both the active 

ingredient (Fontelis and Vertisan), and co-formulated with chlorothalonil (Treoris) formulations) 

toxic effects were observed in honeybees. Therefore, these results indicate that adverse effects to 

terrestrial invertebrates such as pollinators in and around the use areas for the proposed uses of 

penthiopyrad are possible. 
97

Earthworms 

No adverse lethal or sublethal (growth reproductive) effects were observed in earthworms 

exposed to penthiopyrad at 1000 mg a.i./kg dw soil (acute effects) or 48 mg a.i./kg dw soil 

(growth and reproductive effects). Assuming a soil depth of 15cm, the expected concentration of 

penthiopyrad in soil at the maximum application rate of 0.95 lbs a.i./A is 0.53 mg/kg soil. The 

predicted maximum concentration of penthiopyrad in soil is approximately 472x lower than the 

concentration at which no effects to earthworms were observed; therefore, direct exposure to 

penthiopyrad in the soil is not likely to result in adverse effects for earthworms. 

Beneficial insects 

As previously discussed in Section 3.3.2.3, non-guideline toxicity data with the Fontelis and 

Vertisan formulations are also available for two sensitive standard arthropod species, including 

the parasitic wasp (Aphidius rhopalosiphi) and predatory mite (Typhlodromus pyri). The 

reported Fontelis formulation LR50 values were 0.29 lbs a.i./A for the parasitic wasp and 0.11 lbs 

a.i./A for the predatory mite, are approximately 2 times less than the maximum application rate, 

equivalent, or 6 to 7 times higher than the maximum application rate of 0.39 lbs a.i./A for this 

formulated product (Fontelis). Given that 50% mortality of the parasitic wasp and predatory 

mite was observed at exposure concentrations ranging from 1 to 2 times less than the maximum 

application rate of 0.39 lbs a.i./A for two of the studies, it is possible that the use of Fontelis on 

brassica vegetables, legumes (succulent), root vegetables and leaves may adversely affect 

sensitive arthropod species. 

Vertisan is proposed for use at a maximum rate of 0.39 lbs a.i./A. The reported Vertisan 

formulation LR50 values were >0.211 lbs a.i./A for the parasitic wasp and 0.266 lbs a.i./A for the 

predatory mite, are approximately 1.5 times less than the maximum application rate of 0.39 lbs 

a.i./A for this formulated product (Vertisan). Extended laboratory studies completed for the 

predatory mite provide additional information relating to the effects of penthiopyrad on mortality 

and reproduction (fecundity and fertility) of the Vertisan formulated product. The 7-day LR50

and 14-day ER50 values for the predatory mite were 0.0911 lbs a.i./A and >0.0911 lbs a.i./A, 

respectively. From the extended laboratory tests, the predatory mite LR50 was approximately 

four times lower than the maximum application rate of 0.39 lbs a.i./A and two times lower than 

the minimum application rate of 0.21 lbs. a.i./A for this formulated product Vertisan. Given that 

50% mortality of the parasitic wasp and predatory mite and the predatory mite extended 7-day 

LR50 were observed at exposure concentrations 1.5 to 2 times less than the maximum application 

rate of 0.39 lbs a.i./A, it is possible that the use of penthiopyrad on soybeans, sugarbeets, and 

sunflowers may adversely affect sensitive arthropod species. 

Based on the available data, direct adverse effects to terrestrial invertebrates are considered low 

for penthiopyrad technical, but not for the formulations. It is possible that adverse effects to 

terrestrial invertebrates, including pollinators and beneficial insects, may occur based on 

exposure to the Fontelis Vertisan, and Treoris formulated products in and around the use areas of 

the proposed uses of penthiopyrad. However, at this time, risk to these taxa cannot be quantified. 

Submittal of an acceptable honeybee acute contact toxicity study for penthiopyrad technical, 

completed in accordance with OPPTS 850.3020 would eliminate the data gap, however, the 
98

observed toxicity appears to be low for the technical grade material, and a new study is not 

needed at this time. 

4.2.2.4. Terrestrial Plants 

Tier I plant studies demonstrate the need for additional information to determine the potential 

risk of penthiopyrad to affect terrestrial plants. Effects were seen at the single application rate 

that was tested (1.39 lbs ai./A) for both monocot and dicot terrestrial plant species in the seedling 

emergence (ryegrass, wheat and tomato) and vegetative vigor (wheat and soybean) toxicity tests; 

therefore, additional information is needed for these species. Ryegrass exhibited 14% inhibition 

of seedling emergence and survival, wheat exhibited12% inhibition on growth (dry weight), and 

tomato 20% inhibition on growth (dry weight) in the seedling emergence test. Wheat exhibited 

20% inhibition on growth (dry weight), and soybean exhibited 8% inhibition on growth (dry 

weight) in the vegetative vigor test. There were no adverse effects on seedling condition, 

survival, dry weight and height of the remaining terrestrial plant species tested, and overall, there 

were no species that had an inhibition of 25% or greater for any endpoint that was tested. 

Therefore, based on these results the EC25>1.39 lbs a.i./A for both seedling emergence and 

vegetative vigor studies. However, it was noted that definitive NOAEC’s were not obtained for 

ryegrass, wheat, and tomato (seedling emergence study), and wheat and soybean (vegetative 

vigor study), as these species exhibited treatment related reductions at the limit concentration 

relative to the negative control. 

With respect to the monocots ryegrass and wheat, and the dicots tomato and soybean, due to the 

presence of effects at the single application rate of 1.39 lbs a.i./A, without additional data to 

define a NOAEC an assumption of risk to listed plants will be made. However, there were less 

than 25% effects observed at a level above the highest proposed application rate, risks to nonlisted plants and indirect effects to listed animals with no obligate relationships with plants can 

be discounted. Risk to listed plants and animals with obligate relationships with plants cannot be 

discounted. Ryegrass, wheat, tomato, and soybean exhibited statistically significant reductions 

at the limit concentration relative to the negative control, although Tier II studies are not required 

as no effects were greater than 25%, Tier II studies would reduce the uncertainty regarding listed 

species. As a result accurate RQ values could not be calculated, and risk to listed monocot plants 

inhabiting dry and semi-aquatic areas exposed to penthiopyrad via runoff and drift for aerial and 

ground applications is assumed. Additionally, the dicots, tomato exhibited effects in the seedling 

emergence test and soybean exhibited effects in the vegetative vigor test at the tested single 

application rate (1.39 lbs a.i./A). As a result, accurate RQ values could not be calculated, and 

risk to listed dicot plants inhabiting dry and semi-aquatic areas exposed to penthiopyrad via 

runoff and drift for aerial and ground applications is assumed. The single application rate that 

was tested is above the single maximum application rate for the proposed uses; however, with 

effects seen at this application rate, there is the potential of effects seen at the current proposed 

uses. Therefore, to eliminate uncertainty, risk can likely be reduced with the submission of tier 

II toxicity studies for these four species. Due to effects seen at the single application rate for 

both terrestrial monocot and dicot plant species in the seedling emergence and vegetative vigor 

toxicity tests, risk to terrestrial plants and animals with obligate relationships with plants are 

assumed. 
99

5. Federally Threatened and Endangered (Listed) Species 

Concerns

Section 7 of the Endangered Species Act, 16 U.S.C. Section 1536(a)(2), requires all federal 

agencies to consult with the National Marine Fisheries Service (NMFS) for marine and 

anadromous listed species, and/or the United States Fish and Wildlife Service (USFWS) for 

listed wildlife and freshwater organisms, if they are proposing an "action" that may affect listed 

species or their designated critical habitat. Each federal agency is required under the Act to 

ensure that any action they authorize, fund, or carry out is not likely to jeopardize the continued 

existence of a listed species or result in the destruction or adverse modification of designated 

critical habitat. To jeopardize the continued existence of a listed species means "to engage in an 

action that reasonably would be expected, directly or indirectly, to reduce appreciably the 

likelihood of both the survival and recovery of a listed species in the wild by reducing the 

reproduction, numbers, or distribution of the species" (50 C.F.R. § 402.02). 

To facilitate compliance with the requirements of the Endangered Species Act (subsection 

(a)(2)), the Office of Pesticide Programs has established procedures to evaluate whether a 

proposed registration action may directly or indirectly appreciably reduce the likelihood of both 

the survival and recovery of a listed species in the wild by reducing the reproduction, numbers, 

or distribution of any listed species (USEPA, 2004). After the Agency’s screening level risk 

assessment is conducted, if any of the Agency’s listed species LOCs are exceeded for either 

direct or indirect effects, an analysis is conducted to determine if any listed or candidate species 

may co-occur in the area of the proposed pesticide use or areas downstream or downwind that 

could be contaminated from drift or runoff/erosion. If listed or candidate species may be present 

in the proposed action area, further biological assessment is undertaken. The extent to which 

listed species may be at risk is considered, which then determines the need for the development 

of a more comprehensive consultation package, as required by the Endangered Species Act. 

The federal action addressed herein is the proposed new registration of penthiopyrad on 

agricultural and non-agricultural use sites. Given that penthiopyrad can be used on both turf and 

landscape ornamental areas, it is expected that its use could occur nationwide. 

 5.1. Action Area 

For listed species assessment purposes, the action area is considered to be the area affected 

directly or indirectly by penthiopyrad use and not merely the immediate area where penthiopyrad 

is applied. At the initial screening-level, the risk assessment considers broadly described 

taxonomic groups and conservatively assumes that listed species within those broad groups are 

co-located with the pesticide treatment area. This means that listed terrestrial plants and wildlife 

are assumed to be located on or adjacent to the treated site and listed aquatic organisms are 

assumed to be located in a surface water body adjacent to the treated site. The assessment also 

assumes that the listed species are located within an assumed area, which has the relatively 

highest potential exposure to the pesticide, and that exposures are likely to decrease with 

distance from the treatment area. Section 3.1 of this risk assessment presents the proposed 

pesticide use sites that are used to establish initial co-location of species with treatment areas. 
100

 5.2. Taxonomic Groups Potentially at Risk 

 

If the assumptions associated with the screening-level action area result in RQs that are below 

the listed species LOCs, a "no effect" determination conclusion is made with respect to listed 

species in that taxa, and no further refinement of the action area is necessary. Furthermore, RQs 

below the listed species LOCs for a given taxonomic group indicate no concern for indirect 

effects on listed species that depend upon the taxonomic group for which the RQ was calculated. 

However, in situations where the screening assumptions lead to RQs in excess of the listed 

species LOCs for a given taxonomic group, a potential for a "may affect" conclusion exists and 

may be associated with direct effects on listed species belonging to that taxonomic group or may 

extend to indirect effects upon listed species that depend upon that taxonomic group as a 

resource. In such cases, additional information on the biology of listed species, the locations of 

these species, and the locations of use sites are considered to determine the extent to which 

screening assumptions regarding an action area apply to a particular listed organism. These 

subsequent refinement steps will consider how this information would impact the action area for 

a particular listed organism and potentially include areas of exposure that are downwind and 

downstream of the pesticide use site. 

Assessment endpoints, exposure pathways, and the conceptual models addressing proposed new 

penthiopyrad uses, and the associated exposure and effects analyses conducted for the 

penthiopyrad screening-level risk assessment are in Sections 2 to 3. The assessment endpoints 

used in the screening-level risk assessment include those defined operationally as reduced 

survival and reproductive impairment for both aquatic and terrestrial animal species and survival, 

reproduction, and growth of aquatic and terrestrial plant species from both direct acute and 

chronic exposures. These assessment endpoints are intended to address the standard set forth in 

the Endangered Species Act requiring federal agencies to ensure that any action they authorize 

does not appreciably reduce the likelihood of both the survival and recovery of a listed species in 

the wild by reducing the reproduction, numbers, or distribution of the species. Risk estimates 

(RQs) which, integrating exposure and effects, are calculated for broad based taxonomic groups 

in the screening-level risk assessment presented in Section 4.

Both acute listed species and chronic risk LOCs are considered in the screening-level risk 

assessment to identify direct and indirect effects to taxa of listed species. This section identifies 

direct effect concerns, by taxa, that are triggered by exceeding endangered LOCs in the 

screening-level risk assessment, with an evaluation of the potential probability of individual 

effects for exposures that may occur at the established endangered species LOC. Data on 

exposure and effects collected under field and laboratory conditions are evaluated to make 

determinations on the predictive utility of the direct effect screening assessment findings to listed 

species. Additionally, the results of the screen for indirect effects to listed species, using direct 

effect acute and chronic LOCs for each taxonomic group, is presented and evaluated. Identified 

potential direct and indirect risks to listed species that may result from the proposed uses of 

penthiopyrad (except use on cranberries) are summarized in Table 5.1. The potential direct and 

indirect risks to listed species that may result from the proposed cranberry use is summarized in 

Table 5.1a.
101

Table 5.1. Potential Effects to Federally Listed Taxa Associated with Direct or Indirect 

Effects from the Proposed Uses of Penthiopyrad (all uses except cranberries).

Listed Taxon Direct 

Effects Uses of Concern Indirect 

Effects Uses of Concern 

Terrestrial and semiaquatic plants - 

monocots 

Yes All uses Yes2 All uses 

Terrestrial and semiaquatic plants - dicots Yes All uses Yes2 All uses 

Birds No None Yes1,2,3 All uses 

Terrestrial-phase 

amphibians No None Yes1,2,3 All uses 

Reptiles No None Yes1,2,3 All uses 

Mammals Yes All uses Yes1,3 All uses 

Terrestrial invertebrates Yesa All uses Yes1 All uses 

Aquatic vascular and 

non-vascular plants No None Yes3

 All uses 

Freshwater fish Yes All uses except canola Yes1,3 All uses 

Aquatic-phase 

amphibians Yes All uses except canola Yes1,3 All uses 

Freshwater 

invertebrates No None Yes1,3 All uses 

Mollusks No None Yes1,3 All uses 

Marine/estuarine fish Yesb All uses Yes1,3 All uses 

Marine/estuarine 

invertebrates Yesb

 All uses Yes1,3 All uses 

Sediment-dwelling 

organisms No None Yes3

 All uses 

a

 RQs were not calculated due to lack of a standard quantification methodology for non-listed species. Therefore, the 

‘LOC exceedance’ was based on lines of evidence including application rate, toxicity data (both pollinators and 

beneficial insects), and the mode of action of penthiopyrad. 

b Risk cannot be precluded via spray drift of the Fontelis formulation to water bodies with lack of data for the 

Fontelis formulation for estuarine/marine fish and invertebrates.

Potential indirect effects on a taxon attributable to: 1

 direct effects on plants (terrestrial and semi-aquatic) 2

 direct chronic effects on mammals 

3

 direct acute effects on freshwater fish and aquatic-phase amphibians 

Table 5.1a. Potential Effects to Federally Listed Taxa Associated with Direct or Indirect 

Effects from the Proposed Uses of Penthiopyrad on Cranberries*. 

Listed Taxon Direct 

Effects Uses of Concern Indirect 

Effects Uses of Concern 

Terrestrial and semiaquatic plants - 

monocots 

Yes All uses Yes2 All uses 

Terrestrial and semiaquatic plants - dicots Yes All uses Yes2 All uses 

Birds No None Yes1,2,3 All uses 

Terrestrial-phase 

amphibians No None Yes1,2,3 All uses 

Reptiles No None Yes1,2,3 All uses 

Mammals Yes All uses Yes1,3 All uses 

Terrestrial invertebrates Yesa All uses Yes1 All uses 
102

Listed Taxon Direct 

Effects Uses of Concern Indirect 

Effects Uses of Concern 

Aquatic vascular and 

non-vascular plants No None Yes3

 All uses 

Freshwater fish Yes Cranberry Yes1,3 All uses 

Aquatic-phase 

amphibians Yes Cranberry Yes1,3 All uses 

Freshwater 

invertebrates Yes Cranberry Yes1,3 All uses 

Mollusks Yes Cranberry Yes1,3 All uses 

Marine/estuarine fish Yesb Cranberry Yes1,3 All uses 

Marine/estuarine 

invertebrates Yesb

 Cranberry Yes1,3 All uses 

Sediment-dwelling 

organisms No None Yes3

 All uses 

* Based on the refined cranberry model calculated EEC values, and derived acute and chronic RQs. The Tier I rice 

model calculated EEC value results in potential direct adverse acute and chronic effects to all aquatic organisms, as 

well as aquatic non-vascular plants. 

a

 RQs were not calculated due to lack of a standard quantification methodology for non-listed species. Therefore, the 

‘LOC exceedance’ was based on lines of evidence including application rate, toxicity data (both pollinators and 

beneficial insects), and the mode of action of penthiopyrad. 

b Risk cannot be precluded via spray drift of the Fontelis formulation to water bodies with lack of data for the 

Fontelis formulation for estuarine/marine fish and invertebrates.

Potential indirect effects on a taxon attributable to: 1

 direct effects on plants (terrestrial and semi-aquatic) 2

 direct chronic effects on mammals 

3

 direct acute effects on freshwater fish and invertebrates, aquatic-phase amphibians, estuarine/marine fish and 

invertebrates; and direct chronic effects on freshwater fish and estuarine/marine invertebrates (based on the refined 

cranberry model calculated EEC values, and derived acute and chronic RQs). 

 5.2.1. Probit Dose-Response Analysis 

The Agency uses the probit dose-response relationship as a tool for providing additional 

information on the potential for acute direct effects to individual listed species and aquatic 

animals that may indirectly affect the listed species of concern (USEPA, 2004). As part of this 

evaluation, the acute RQ for listed species is presented in terms of the chance of an individual 

event (i.e., mortality or immobilization) should exposure at the EEC actually occur for a species 

with sensitivity to penthiopyrad on par with the acute toxicity endpoint selected for RQ 

calculation. To accomplish this interpretation, the Agency uses the slope of the dose-response 

relationship available from the toxicity study used to establish the acute toxicity measures of 

effect for each taxonomic group that is relevant to this assessment. The individual effects 

probability associated with the acute RQ is based on the mean estimate of the slope and an 

assumption of a probit dose-response relationship. In addition to a single effects probability 

estimate based on the mean, upper and lower estimates of the effects probability are also 

provided to account for variance in the slope, if available. Based on the available acute toxicity 

for penthiopyrad, a summary of the probit dose-response analysis is provided in Table 5.2. If no 

dose response information is available to estimate a slope for this analysis, a default slope 

assumption of 4.5 (with lower and upper bounds of 2 to 9) (Urban and Cook, 1986) is used. 
103

Individual effect probabilities are calculated based on an Excel spreadsheet tool IECV1.1 

(Individual Effect Chance Model Version 1.1) developed by the U.S. EPA, OPP, Environmental 

Fate and Effects Division (June 22, 2004). The model allows for such calculations by entering 

the mean slope estimate (and the 95% confidence bounds of that estimate) as the slope parameter 

for the spreadsheet. The desired threshold for the probability of an individual effect is entered as 

the listed species LOC. In addition, the probability of an individual effect is also derived based 

on the calculated acute RQ, if available. 

Table 5.2. Summary of Penthiopyrad Probit Dose Response Analysis for Listed Species 

(Based on the Proposed Cranberry Use)

Taxa (study type) Acute Effect 

Slope (95% C.I.) 

Chance of Individual 

Effect at Listed Species 

LOC (95% C.I.)1

Chance of Individual Effect 

at Derived Acute RQ2,3,4,5 

(95% C.I.) 

Bird (oral dose) No mortality observed 

Slope NA = 4.5 (2 – 9) 

1 in 2.94E+05 

(1 in 440 to 1 in 

8.86E+18)1 

Not calculated; no mortality 

observed 

Bird (dietary) No mortality observed 

Slope NA = 4.5 (2 – 9)

1 in 2.94E+05 

(1 in 440 to 1 in 

8.86E+18)1

Not calculated; no mortality 

observed

Mammal (oral dose) No mortality observed 

Slope NA = 4.5 (2 – 9)

1 in 2.94E+05 

(1 in 440 to 1 in 

8.86E+18)1

Not calculated; no mortality 

observed

Freshwater fish (acute) 

Mortality and sublethal 

effects 

Slope NA = 4.5 (2 – 9)

1 in 4.18E+08 

(1 in 216 to 1 in 

1.75E+31)

1 in 1 

(1 in 1 to 1 in 1)2

Freshwater 

invertebrates (acute) 

Immobilization and sublethal 

effects 

Slope 10.3 (6.06 – 14.5) 

1 in 3.34E+40 

(1 in 6.32E+14 to 1 in 

9.03E+78)

1 in 6.83E+11 

(1 in 50,000 to 1 in 2.34E+22)3

Estuarine/marine fish 

(acute) 

Mortality and sublethal 

effects 

Slope NA = 4.5 (2 – 9) 

1 in 4.18E+08 

(1 in 216 to 1 in 

1.75E+31) 

1 in 34 

(1 in 5 to 1 in 12, 900)4 

Estuarine/marine 

invertebrates (acute) 

Shell deposition 

Slope = 3.59 (2.26 – 4.92) 

1 in 6.66E+05 

(1 in 610 to 1 in 

1.30E+10) 

1 in 10 

(1 in 5 to 1 in 252)5

1

 Although no mortality was observed, the chance of individual effect at the listed species LOC (0.1) for terrestrial 

animals was calculated using the default slope of 4.5 (2 – 9), and the threshold of 0.1 (the listed species LOC). 

2 Acute RQ for freshwater fish = 1.8. 

3

 Acute RQ for freshwater invertebrates = 0.21. 

4

 Acute RQ for estuarine/marine fish = 0.38. 5

 Acute RQ estuarine/marine invertebrates = 0.44. 

As shown in Table 5.2, the probability for acute direct effects (i.e., mortality) to individual listed 

freshwater fish at the highest derived RQ value is 1 in 1 (100%). The probability for acute direct 

effects (i.e., mortality) to individual listed estuarine/marine fish is 1 in 34 (2.9%). The 

probability for acute direct effects (i.e., mortality) to individual listed estuarine/marine 

invertebrates is 1 in 10 (10%). The probability for acute direct effects (i.e., mortality) to 

individual listed freshwater invertebrates at the highest derived RQ value is 1 in 6.83E+11 

(<0.01%). The chance of an individual effect was not derived for taxa other than those listed 

above. In summary, the chance of individual effects to listed freshwater fish species based on 

effects of penthiopyrad is high (100%) for the highest derived RQs based on the maximum 
104

application rate EECs of all the proposed uses of penthiopyrad. In addition, the chance of 

individual effects to listed estuarine/marine fish and invertebrate species based on effects of 

penthiopyrad is low (2.9 and 10%, respectively) for the highest derived RQs based on the 

maximum application rate EECs of all the proposed uses of penthiopyrad. 

5.2.2. Listed Species Occurrence Associated with Penthiopyrad Use 

The goal of the co-location analysis is determine whether sites of pesticide use are 

geographically associated with known locations of listed species [following the convention of the 

Services, the word ‘species’ in this assessment may apply to a ‘species’, ‘subspecies’, or an 

Evolutionary Significant Unit (ESU)]. At the screening level, this analysis is accomplished 

using the LOCATES database (version 2.2.1). The database uses location information for listed 

species at the county level and compares it to agricultural census data (from 2007) for crop 

production at the same county level of resolution. The product is a listing of Federally-listed 

species that are located in counties known to produce the crops upon which the pesticide will be 

used. 

The results of this baseline-level risk assessment indicate that the proposed uses of penthiopyrad 

have the potential for direct adverse acute effects on listed and non-listed freshwater fish (a 

surrogate for aquatic-phase amphibians); acute effects on listed freshwater invertebrates, 

estuarine/marine fish and invertebrates; chronic effects to freshwater fish and estuarine/marine 

invertebrates; acute effects on listed estuarine/marine fish and invertebrates (via spray drift from 

Fontelis formulated product); and chronic effects on listed and non-listed mammals based on all 

proposed use patterns. Due to effects seen at the single application rate for both terrestrial 

monocot and dicot plant species in the seedling emergence and vegetative vigor toxicity tests, 

risk to terrestrial plants and animals with obligate relationships with plants are assumed. 

Although direct adverse effects to birds, terrestrial-phase amphibians, and reptiles, from 

penthiopyrad use are not expected, indirect effects to these taxa are possible, given the chronic 

effects on mammals could indirectly impact terrestrial organisms that feed on these species. 

Therefore, all listed species occurring nationwide may potentially be affected by the proposed 

new registration of penthiopyrad. Because there is a potential for indirect effects to all listed 

taxa and all proposed uses of penthiopyrad may occur anywhere in the United States or its 

territories, state and county-level summaries from LOCATES are not provided. However, based 

on the U.S. Fish and Wildlife Services Endangered Species Program there are a total of 1,383 

listed species in the United States that may be directly or indirectly affected by the proposed new 

uses of penthiopyrad (http://www.fws.gov/endangered/species/us-species.html). 

This preliminary analysis indicates that there is a potential for penthioyprad use to overlap with 

listed species and that a more refined assessment is warranted. The more refined assessment 

should involve clear delineation of the action area associated with proposed uses of penthioyprad 

and the best available information on the temporal and spatial co-location of listed species with 

respect to the action area. This analysis has not been conducted for this assessment. 
105

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TFA in the Environment, February 8–9, 1994, Washington, DC. Published by AFEAS. 

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108

 6.1. Submitted Product Chemistry and Environmental Fate Studies 

MRID 47614817. Tognucci, A. (1999) Determination of the Vapour Pressure of MTF-753. 

Project Number: 728368, 753/2/03. Unpublished study prepared by RCC Umweltchemie 

Ag. 20 p. 

MRID 47614820. Labano, S. (2009) Penthiopyrad: Calculation of Henry's Law Constant. Project 

Number: 08/LKC/03, 753/2/56. Unpublished study prepared by LKC Switzerland, Ltd. 6 

p. 

MRID 47614828. Franke, J. (2008) Determination of the Water Solubility of MTF-753 Including 

Effect of pH and Temperature. Project Number: A79435, 753/2/54. Unpublished study 

prepared by Harlan Laboratories, Ltd. 69 p. 

MRID 47614829. Tognucci, A. (1999) Determination of the Solubility of MTF-753 in Water and 

in Organic Solvents. Project No.: 728370, 753/2/04. Unpublished study prepared by RCC 

Umweltchemie Ag. 29 p. 

MRID 47614832. Franke, J. (2008) Determination of the Partition Coefficient (NOctanol/Water) of MTF-753 Including Effect of pH and Temperature. Project Number: 

A79424, 753/2/55. Unpublished study prepared by Harlan Laboratories, Ltd. 44 p. 

MRID 47614837. Tognucci, A. (1999) Hydrolysis Determination of MTF-753 at Different pH 

Values. Project Number: 728381, 753/2/06. Unpublished study prepared by RCC 

Umweltchemie Ag. 23 p. 

MRID 47614839. Burgener, A. (1999) Aqueous Photolysis of MTF-753 under Laboratory 

Conditions. Project Number: 728414, 753/2/07. Unpublished study prepared by RCC 

Umweltchemie Ag. 33 p. 

MRID 47614840. Tognucci, A. (1999) Determination of the Dissociation Constant of MTF-753 

in Water. Project Number: 728403, 753/2/08. Unpublished study prepared by RCC 

Umweltchemie Ag. 20 p. 

MRID 47614841. Schreitmuller, J. (2006) Dissociation Constant of MTF-753: Final Report. 

Project Number: 728403. Unpublished study prepared by RCC Umweltchemie Ag. 4 p. 

MRID 47614959. Mamouni, A. (2008) (Carbon 14)-MTF-753: Degradation and Metabolism in 

Four Soils Incubated Under Aerobic Conditions. Unpublished study prepared by RCC, 

Ltd. 224 p. 

MRID 47614961. Mamouni, A. (2008) (Carbon 14)-MTF-753: Degradation and Metabolism in 

on North American Soil Incubated Under Aerobic Conditions. Project Number: A56226, 

A56226/OCR, 753/7/12. Unpublished study prepared by RCC, Ltd. 115 p. 
109

MRID 47614963. Satsuma, K. (2005) Metabolic Fate of MTF-753 in Aerobic Soil: Final Report. 

Project Number: IET/03/8002, IET/03/8002/OCR, 753/7/04. Unpublished study prepared 

by Institute of Environmental Toxicology. 105 p. 

MRID 47614964. Mamouni, A. (2007) (Carbon 14)-MTF-753: Degradation and Metabolism in 

One Soil Incubated Under Anaerobic Conditions. Project Number: A59580, 

A59580/OCR. Unpublished study prepared by RCC, Ltd. 118 p. 

MRID 47614965. Mamouni, A. (2008) (Carbon 14)-MTF-753: Phototransformation on Soil 

Surfaces Under Laboratory Conditions. Project Number: A56204, A56204/OCR, 

753/7/11. Unpublished study prepared by RCC, Ltd. 127 p. 

MRID 47614966. Volkel, W. (2009) (Carbon 14)-DM-PCA: Rate and Route of Degradation and 

Time-Dependent Sorption in Four Soils: Final Report. Project Number: A59567, 

A59567/OCR, 753/7/18. Unpublished study prepared by Harlan Laboratories, Ltd. 112 p. 

MRID 47614967. Volkel, W. (2007) (Carbon 14)-MTF-753: Adsorption/Desorption on Soils. 

Project Number: A59556, A59556/OCR, 753/7/05. Unpublished study prepared by RCC, 

Ltd. 106 p. 

MRID 47614971. Morriss, A. (2009) Determination of the Adsorption Coefficient (Koc) for 

PAM Using a Batch Equilibrium Method: Final Report. Project Number: 

CEMS/3837/OCR, CEMS/3837, CEMR/3837. Unpublished study prepared by CEM 

Analytical Services, Ltd. 48 p. 

MRID 47614972. Edwards, J. (2009) Determination of the Adsorption Coefficient (Koc) for 

753-A-OH Using a Batch Equilibrium Method: Final Report. Project Number: 

CEMS/4207, CEMS/4207/OCR, CEMR/4207. Unpublished study prepared by CEM 

Analytical Services, Ltd. 47 p. 

MRID 47614973. Edwards, J. (2009) Determination of the Adsorption Coefficient (Koc) for 

753-T-DO Using a Batch Equilibrium Method: Final Report. Project Number: 

CEMS/4206, CEMS/4206/OCR, CEMR/4206. Unpublished study prepared by CEM 

Analytical Services, Ltd. 45 p. 

MRID 47614974. Seyfried, B. (2007) MTF-753: Ready Biodegradability in a Manometric 

Respirometry Test. Project Number: A59613, A59613/OCR, 753/7/06. Unpublished 

study prepared by RCC, Ltd. 40 p. 

MRID 47614975. Adam, D. (2008) (Carbon 14)-MTF-753: Route and Rate of Degradation in 

Aerobic Aquatic Sediment Systems. Project Number: A59591, A59591/OCR, 753/7/09. 

Unpublished study prepared by RCC, Ltd. 160 p. 
110

MRID 47614976. Adam, D. (2007) (Carbon 14)-MTF-753: Route and Rate of Degradation in an 

Anaerobic Aquatic Sediment System. Project Number: A59602, A59602/OCR, 753/7/08. 

Unpublished study prepared by RCC, Ltd. 106 p. 

MRID 47615162. Huang, F. (2008) Terrestrial Field Dissipation of Penthiopyrad (MTF-753) on 

Bare Soil in California, USA. Project Number: DUPONT/19660, DUPONT/19660/OCR, 

50214. Unpublished study prepared by ABC Laboratories, Inc., and E.I. du Pont de 

Nemours and Company. 310 p. 

MRID 47615163. Huang, F. (2008) Terrestrial Field Dissipation of Penthiopyrad (MTF-753) on 

Bare Soil in Georgia, USA. Project Number: DUPONT/19661, DUPONT/19661/OCR, 

50217. Unpublished study prepared by ABC Laboratories, Inc., and E.I. du Pont de 

Nemours and Company. 313 p. 

MRID 47615164. Huang, F. (2008) Terrestrial Field Dissipation of Penthiopyrad (MTF-753) in 

Missouri, USA. Project Number: DUPONT/19662, DUPONT/19662/OCR, 50216. 

Unpublished study prepared b ABC Laboratories, Inc., and E.I. du Pont de Nemours and 

Company. 307 p. 

MRID 47615165. Huang, F. (2008) Terrestrial Field Dissipation of Penthiopyrad (MTF-753) in 

Washington, USA. Project Number: DUPONT/19663, DUPONT/19663/OCR, 50215. 

Unpublished study prepared by ABC Laboratories, Inc., and E.I. du Pont de Nemours and 

Company. 383 p. 

MRID 47615166. Huang, F.; Rice, A. (2008) Terrestrial Field Dissipation of Penthiopyrad 

(MTF-753) on Bare Soil in Ontario, Canada. Project Number: DUPONT/19664, 

DUPONT/19664/OCR, 50218. Unpublished study prepared by ABC Laboratories, Inc., 

and E.I. du Pont de Nemours and Company. 286 p. 

MRID 47615167. Huang, F.; Rice, F.; Gant, A. (2008) Terrestrial Field Dissipation of 

Penthiopyrad (MTF-753) on Bare Soil in Saskatchewan, Canada. Project Number: 

DUPONT/19665, DUPONT/19665/OCR, 50219. Unpublished study prepared by ABC 

Laboratories, Inc., and E.I. du Pont de Nemours and Company. 278 p. 

MRID 47615172. Huang, F.; Rice, F.; Gant, A. (2009) Terrestrial Field Dissipation of 

Penthiopyrad (MTF-753) on Turf in New York, 2007, USA. Project Number: 

DUPONT/21865, DUPONT/21865/OCR, 62316. Unpublished study prepared by ABC 

Laboratories, Inc. 300 p. 

MRID 47615173. Huang, F.; Rice, F.; Gant, A. (2009) Terrestrial Field Dissipation of 

Penthiopyrad (MTF-753) on Turf in Georgia, 2007, USA. Project Number: 

DUPONT/21866, DUPONT/21866/OCR, 62323. Unpublished study prepared by ABC 

Laboratories, Inc. 256 p. 
111

 6.2. Submitted Ecotoxicity Studies 

MRID Citation

47614977 Gallagher, S.; Beavers, J. (2005) MTF-753: An Acute Oral Toxicity Study with the 

Northern Bobwhite. Project Number: 236/118/OCR, 236/118, 8147. Unpublished 

study prepared by Wildlife International, Ltd. 51 p. 

47614978 Hubbard, P.; Beavers, J. (2009) MTF-753: An Acute Oral Toxicity Study with the 

Zebra Finch (Poephila guttatta). Project Number: 236/130, 236/130/OCR, 753/8/61. 

Unpublished study prepared by Wildlife International, Ltd. 56 p. 

47614979 Gallagher, S.; Martin, K.; Beavers, J. (2008) MTF-753: A Dietary LC50 Study with 

the Northern Bobwhite. Project Number: 236/121, 236/121/OCR, 753/8/10. 

Unpublished study prepared by Wildlife International, Ltd. 66 p. 

47614980 Martin, K.; Nixon, W. (2007) Analytical Method Validation for the Determination of 

MTF-753 in Avian Diet. Project Number: 236C/144, 236C/144/OCR, 753/8/11. 

Unpublished study prepared by Wildlife International, Ltd. 30 p. 

47614981 Gallagher, S.; Martin, K.; Beavers, J. (2008) MTF-753: A Dietary LC50 Study with 

the Mallard. Project Number: 236/122, 236/122/OCR, 753/8/09. Unpublished study 

prepared by Wildlife International, Ltd. 67 p. 

47614982 Temple, D.; Martin, K.; Beavers, J.; et al. (2008) MTF-753: A Reproduction Study 

with the Northern Bobwhite: Final Report. Project Number: 236/125/OCR, 236/125, 

753/8/20. Unpublished study prepared by Wildlife International, Ltd. 161 p. 

47614983 Temple, D.; Martin, K.; Beavers, J.; et al. (2008) MTF-753: A Reproduction Study 

with the Mallard: Final Report. Project Number: 753/8/21, 236/126, 236/126/OCR. 

Unpublished study prepared by Wildlife International, Ltd. 158 p. 

47614984 Palmer, S.; Kendall, T.; Krueger, H. (2007) MTF-753: A 96-Hour Static Acute 

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

Number: 236A/112A, 236A/112A/OCR, 753/8/17. Unpublished study prepared by 

Wildlife International, Ltd. 59 p. 

47614985 Kendall, T.; Nixon, W. (2007) Analytical Method Validation for the Determination 

of MTF-753 in Freshwater and Saltwater. Project Number: 236C/145, 

236C/145/OCR. Unpublished study prepared by Wildlife International Ltd. 54 p. 

47614986 Anai, M. (2005) A 96-Hour Acute Toxicity Test of MTF-753 with Common Carp: 

Final Report. Project Number: 93440, 93440/OCR, E04/3440. Unpublished study 

prepared by Kurume Laboratory. 51 p. 

47614987 Palmer, S.; Kendall, T.; Krueger, H. (2007) MTF-753: A 96-Hour Static Acute 

Toxicity Test with the Bluegill (Lepomis macrochirus): Final Report. Project 

Number: 236A/111, 236A/111/OCR, 753/8/12. Unpublished study prepared by 

Wildlife International, Ltd. 59 p. 
112

MRID Citation

47614988 Minderhout, T.; Kendall, T.; Krueger, H. (2009) Penthiopyrad: A 96-Hour StaticRenewal Acute Toxicity Test with the Fathead Minnow (Pimephales Promelas): 

Final Report. Project Number: 236A/120, 236A/120/OCR. Unpublished study 

prepared by Wildlife International, Ltd. 59 p. 

47614989 Bormann, K. (2008) Assessment of Toxic Effects of DM-PCA in Rainbow Trout 

(Oncorhynchus mykiss) Using the 96 Hour Static, Acute Limit Test: Final Report. 

Project Number: 20071562/01/AAOM, 20071562/01/AAOM/OCR, 753/8/35. 

Unpublished study prepared by Eurofins - GAB GmbH. 38 p. 

47614990 Peither, A. (2008) PCA: Acute Toxicity to Zebra Fish (Brachydanio rerio) in a 96-

Hour Static Test: Final Report. Project Number: B57374, B/57374/OCR, 753/8/27. 

Unpublished study prepared by RCC, Ltd. 38 p. 

47614991 Oishi, N. (2008) Acute Toxicity Study of PAM in Rainbow Trout: Final Report. 

Project Number: B130/077/075, B130/077/075/OCR. Unpublished study prepared by 

Biosafety Research Center. 58 p. 

47614992 Minderhout, T.; Kendall, T.; Krueger, H. (2009) 753-A-OH: A 96-Hour Static Acute 

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

Number: 236A/129, 236A/129/OCR. Unpublished study prepared by Wildlife 

International, Ltd. 57 p. 

47614993 Minderhout, T.; Kendall, T.; Krueger, H. (2009) 753-T-DO: A 96-Hour Static Acute 

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

Number: 236A/126, 236A/126/OCR. Unpublished study prepared by Wildlife 

International, Ltd. 58 p. 

47614994 Minderhout, T.; Kendall, T.; Krueger, H. (2008) MTF-753: An Early Life-Stage 

Toxicity Test with the Fathead Minnow (Pimephales promelas): Final Report. Project 

Number: 236A/119, 236A/119/OCR, 753/8/31. Unpublished study prepared by 

Wildlife International, Ltd. 97 p. 

47614995 Burri, R. (2008) Bioconcentration: Flow-Through Fish Test with [Carbon 14]MTF753 in Rainbow Trout (Oncorhynchus mykiss). Project Number: A59545, 

A59545/OCR. Unpublished study prepared by Harlan Laboratories, Ltd. 96 p. 

47614996 Maeda, M. (2005) A 48-Hour Acute Immobilization Test of MTF-753 with Daphnia 

magna: Final Report. Project Number: 93439, 93439/OCR, 753/8/04. Unpublished 

study prepared by Kurume Laboratories. 41 p. 

47614997 Borrmann, K. (2008) Assessment of Toxic Effects of DM-PCA on Daphnia magna 

Using the 48 Hour Static, Acute Limit Test: Final Report. Project Number: 

20071562/01/AADM, 20071562/01/AADM/OCR, 753/8/34. Unpublished study 

prepared by Eurofins - GAB GmbH. 37 p. 
113

MRID Citation

47614998 Schmidt, T. (2008) PCA: Acute Toxicity to Daphnia magna in a 48-Hour 

Immobilization Test: Final Report. Project Number: B57396, B57396/OCR. 

Unpublished study prepared by RCC, Ltd. 38 p. 

47614999 Oishi, N. (2008) Acute Immobilization Study of PAM in Daphnia Magna: Final 

Report. Project Number: B131/077/076, B131/077/076/OCR. Unpublished study 

prepared by Biosafety Research Center. 63 p. 

47615000 Mitsui Chemicals Agro, Inc. (2010) Submission of Product Chemistry, Toxicity, 

Residue, Environmental Fate and Fate Data in Support of the Application for 

Registration of Penthiopyrad Technical. Transmittal of 41 of 292 Studies. 

47615001 Minderhout, T.; Kendall, T.; Krueger, H. (2009) 753-A-OH: A 48-Hour Static Acute 

Toxicity Test with the Cladoceran (Daphnia magna): Final Report. Project Number: 

236A/128, 236A/128/OCR. Unpublished study prepared by Wildlife International, 

Ltd. 56 p. 

47615002 Minderhout, T.; Kendall, T.; Krueger, H. (2009) 753-T-DO: A 48-Hour Static Acute 

Toxicity Test with the Cladoceran (Daphnia magna): Final Report. Project Number: 

236A/125, 236A/125/OCR. Unpublished study prepared by Wildlife International, 

Ltd. 58 p. 

47615003 Palmer, S.; Kendall, T.; Krueger, H. (2007) MTF-753: A Flow-Through Life-Cycle 

Toxicity Test with the Cladoceran (Dophnia magna): Final Report. Project Number: 

236A/113, 236A/113/OCR. Unpublished study prepared by Wildlife International, 

Ltd. 79 p. 

47615004 Sueta, S. (2005) Algal Growth Inhibition Test of MTF-753 with Pseudokirchneriella 

subcapitata: Final Report. Project Number: 93438, 93438/OCR. Unpublished study 

prepared by Kurume Laboratories. 45 p. 

47615005 Palmer, S.; Cartee, T.; Kendall, T.; et al. (2009) Penthiopyrad: A 96-Hour Toxicity 

Test with the Freshwater Alga (Pseudokirchneriella subcapitata): Final Report. 

Project Number: 236A/121, 236A/121/OCR. Unpublished study prepared by Wildlife 

International, Ltd. 66 p. 

47615006 Palmer, S.; Cartee, T.; Kendall, T.; et al. (2009) Penthiopyrad: A 96-Hour Toxicity 

Test with the Marine Diatom (Skeletonema costatum): Final Report. Project Number: 

236A/122, 236A/122/OCR. Unpublished study prepared by Wildlife International, 

Ltd. 66 p. 

47615007 Palmer, S.; Cartee, T.; Kendall, T.; et al. (2009) Penthiopyrad: A 96-Hour Toxicity 

Test with the Freshwater Alga (Anabaena flos-aquae): Final Report. Project Number: 

236A/123, 236A/123/OCR. Unpublished study prepared by Wildlife International, 

Ltd. 66 p. 
114

MRID Citation

47615008 Palmer, S.; Cartee, T.; Kendall, T.; et al. (2009) Penthiopyrad: A 96-Hour Toxicity 

Test with the Freshwater Diatom (Navicula pelliculosa): Final Report. Project 

Number: 236A/124, 236A/124/OCR. Unpublished study prepared by Wildlife 

International, Ltd. 66 p. 

47615009 Dengler, D. (2008) Assessment of Effects of DM-PCA on the Growth of the Single 

Cell Green Alga Desmodesmus subspicatus Using the 96 Hour Static, Limit Test: 

Final Report. Project Number: 20071562/01/AADS/OCR, 20071562/01/AADS, 

753/8/32. Unpublished study prepared by Eurofins - GAB GmbH. 41 p. 

47615010 Peither, A. (2008) PCA: Toxicity to Pseudokirchneriella subcapitata (Formerly 

Selenastrum capricornutum) in a 96-Hour Algal Growth Inhibition Test: Final 

Report. Project Number: B57418, B57418/OCR. Unpublished study prepared by 

RCC, Ltd. 49 p. 

47615011 Oishi, N. (2008) Growth Inhibition Study of PAM in a Green Alga: Final Report. 

Project Number: B132/077/077/, B132/077/077/OCR. Unpublished study prepared 

by Biosafety Research Center, Food, Drugs and Pesticides. 59 p. 

47615012 Palmer, S.; Cartee, T.; Kendall, T.; et al. (2009) 753-A-OH: A 96-Hour Toxicity Test 

with the Freshwater Alga: (Pseudokirchneriella subcapitata): Final Report. Project 

Number: 236A/130, 236A/130/OCR. Unpublished study prepared by Wildlife 

International, Ltd. 70 p. 

47615013 Palmer, S.; Cartee, T.; Kendall, T.; et al. (2009) 753-T-DO: A 96-Hour Toxicity Test 

with the Freshwater Alga (Pseudokirchneriella subcapitata): Final Report. Project 

Number: 236A/127, 236A/127/OCR. Unpublished study prepared by Wildlife 

International, Ltd. 70 p. 

47615014 Krueger, H.; Thomas, S.; Kendall, T. (2008) MTF-753: A Prolonged Sediment 

Toxicity Test wtih Chironomus riparius Using Spiked Sediment: Final Report. 

Project Number: 236A/114, 236A/114/OCR. Unpublished study prepared by Wildlife 

International, Ltd. 101 p. 

47615015 Sindermann, A.; Kendall, T.; Krueger, H. (2008) MTF-753: A 7-Day Toxicity Test 

with Duckweed (Lemma gibba G3): Final Report. Project Number: 236A/118, 

236A/118/OCR, 753/8/24. Unpublished study prepared by Wildlife International, 

Ltd. 70 p. 

47615016 Feije, R. (2005) MTF-753: A Single-Dose Oral Laboratory Test to Evaluate the 

Effect on Survival of the Honeybee Apis mellifera L. Project Number: LK003AMO, 

LK003AMO/OCR. Unpublished study prepared by MITOX Consultants. 29 p. 

47615017 Feije, R. (2005) MTF-753: A Single-Dose Laboratory Test to Evaluate the Effect of 

Topical Application on Survival of the Honeybee Apis mellifera L. Project Number: 

LK005AMT, LK005AMT/OCR, 753/8/06. Unpublished study prepared by MITOX 

Consultants. 28 p. 
115

MRID Citation

47615018 Forster, A.; Davies, N. (2007) A Tier 1 Laboratory Study to Determine the Median 

Lethal Rate of MTF-753 20 SC to the Parasitic Wasp Aphidius rhopalosiphi 

(Hymenoptera: Braconidae). Project Number: ER/07/AF519, AF/519/OCR, AF/519. 

Unpublished study prepared by Ecotox Limited. 51 p. 

47615019 Forster, A.; Davies, N. (2007) A Tier 1 Laboratory Study to Estimate the Median 

Lethal Rate of MTF-753 20SC to the Predatory Mite Typhlodromus pyri (Acari: 

Phytoseiidae). Project Number: AF/518, AF/518/OCR, ER/07/AF518. Unpublished 

study prepared by Ecotox Limited. 50 p. 

47615020 Kolzer, U. (2006) Acute Toxicity of MTF-753 Technical on Earthworms, Eisenia 

fetida Using an Artificial Soil Test: Final Report. Project Number: 

20051281/01/NLEF, 20051281/01/NLEF/OCR, 753/8/07. Unpublished study 

prepared by GAB Biotechnologie Gmbh. 32 p. 

47615021 Stabler, D. (2008) Acute Toxicity of DM-PCA on Earthworms, Eisenia fetida Using 

an Artificial Soil Test- Limit Test: Final Report. Project Number: 

20071562/01/NLEF, 20071562/01/NLEF/OCR, 753/8/36. Unpublished study 

prepared by Eurofins - GAB GmbH. 28 p. 

47615022 Stabler, D. (2008) Acute Toxicity of PCA on Earthworms, Eisenia fetida Using an 

Artificial Soil Test: Final Report. Project Number: S08/01596, S08/01596/OCR, 

753/8/38. Unpublished study prepared by Eurofins - GAB GmbH. 31 p. 

47615023 Stabler, D. (2008) Acute Toxicity of PAM on Earthworms, Eisenia fetida Using an 

Artificial Soil Test: Final Report. Project Number: S08/01594, S08/01594/OCR, 

753/8/39. Unpublished study prepared by Eurofins - GAB GmbH. 31 p. 

47615024 Luhrs, U. (2007) Effects of MTF-753 on Reproduction and Growth of Earthworms 

Eisenia fetida in Artificial Soil with 5% Peat: Final Report. Project Number: 

36521022, 36521022/OCR, 753/8/18. Unpublished study prepared by Institut fuer 

Biologische Analytik und Consulting IBACON. 34 p. 

47615025 Stabler, D. (2008) Sublethal Toxicity of DM-PCA to the Earthworm Eisenia fetida in 

Artificial Soil: Final Report. Project Number: S08/00760, S08/00760/OCR, 753/8/37. 

Unpublished study prepared by Eurofins - GAB GmbH. 33 p. 

47615026 Stabler, D. (2009) Sublethal Toxicity of PCA to the Earthworm Eisenia Fetida in 

Artificial Soil: Final Report. Project Number: S08/03213, S08/03213/OCR. 

Unpublished study prepared by Eurofins - GAB GmbH. 33 p. 

47615027 Stabler, D. (2009) Sublethal Toxicity of PAM to the Earthworm Eisenia fetida in 

Artificial Soil: Final Report. Project Number: S08/03212, S08/03212/OCR. 

Unpublished study prepared by Eurofins - GAB GmbH. 32 p. 
116

MRID Citation

47615028 Kolzer, U. (2006) Assessment of the Side Effects of MTF-753 Technical on the 

Activity of the Soil Microflora: Final Report. Project Number: 20051281/01/ABMF, 

2005128/01/ABMF/OCR. Unpublished study prepared by GAB Biotechnologie 

Gmbh & GAB Analytik GmbH. 53 p. 

47615029 Stabler, D. (2008) Assessment of the Side Effects of DM-PCA on the Activity of the 

Soil Microflora: Final Report. Project Number: 20071562/01/ABMF, 

20071562/01/ABMF/OCR. Unpublished study prepared by Eurofins - GAB GmbH. 

52 p. 

47615030 Stabler, D. (2008) Assessment of the Side Effects of PCA on the Activity of the Soil 

Microflora: Final Report. Project Number: S08/01595, S08/01595/OCR. 

Unpublished study prepared by Eurofins - GAB GmbH. 55 p. 

47615031 Stabler, D. (2008) Assessment of the Side Effects of PAM on the Activity of the Soil 

Microflora: Final Report. Project Number: S08/01593, S08/01593/OCR. 

Unpublished study prepared by Eurofins - GAB GmbH. 54 p. 

47615032 Palmer, S.; Kendall, T.; Krueger, H. (2007) MTF-753: A 96-Hour Static-Renewal 

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

Project Number: 236A/115, 236A/115/OCR. Unpublished study prepared by Wildlife 

International, Ltd. 58 p. 

47615033 Palmer, S.; Kendall, T.; Krueger, H. (2008) MTF-753: A 96-Hour Shell Deposition 

Test with the Eastern Oyster (Crassostrea virginica): Final Report. Project Number: 

753/8/26, 236A/117, 236A/117/OCR. Unpublished study prepared by Wildlife 

International, Ltd. 66 p. 

47615034 Palmer, S.; Kendall, T.; Krueger, H. (2007) MTF-753: A 96-Hour Static-Renewal 

Acute Toxicity Test with the Sheepshead Minnow (Cyprinodon variegatus): Final 

Report. Project Number: 236A/116, 236A/116/OCR, 753/8/15. Unpublished study 

prepared by Wildlife International, Ltd. 58 p. 

47615035 Rosenkranz, B.; Luhrs, U. (2009) Effects of MTF-753 20 SC and DM-PCA on the 

Breakdown of Organic Matter in Litter Bags in the Field: Final Report. Project 

Number: 36121081, 36121081/OCR. Unpublished study prepared by Institut fuer 

Biologische Analytik und Consulting IBACON. 120 p. 

47615036 Luhrs, U.; Schabio, S. (2009) Effects of DM-PCA on the Breakdown of Organic 

Matter in Litter Bags in the Field: Final Report. Project Number: 43391081, 

43391081/OCR. Unpublished study prepared by Institut fuer Biologische Analytik 

und Consulting IBACON. 122 p. 

47615037 Porch, J.; Martin, K.; Krueger, H. (2008) MTF-753 20SC: A Toxicity Test to 

Determine the Effects of the Test Substance on Seedling Emergence of Ten Species 

of Plants: Final Report. Project Number: 236/128, 236/128/OCR, 753/8/22. 

Unpublished study prepared by Wildlife International, Ltd. 70 p. 
117

MRID Citation

47615038 Porch, J.; Krueger, H.; Martin, K. (2008) MTF-753 20SC: A Toxicity Test to 

Determine the Effects of the Test Substance on Vegetative Vigor of Ten Species of 

Plants: Final Report. Project Number: 236/129, 236/129/OCR, 753/8/23. 

Unpublished study prepared by Wildlife International, Ltd. 80 p. 

47615039 Dengler, D. (2008) Toxicity Testing of MTF-753 (Penthiopyrad) on MicroOrganisms with the Sludge Respiration Inhibition Test: Final Report. Project 

Number: 20071563/01/AAHT/OCR, 20071563/01/AAHT, 753/8/33. Unpublished 

study prepared by Eurofins - GAB GmbH. 36 p. 

47615040 Kendall, T.; Nixon, W. (2009) Evaluation of the Stability of 753-T-DO in 

Freshwater. Project Number: 236C/155, 236C/155/OCR. Unpublished study prepared 

by Wildlife International, Ltd. 35 p. 

47615041 Luhrs, U. (2009) Effects of MTF-753 20 SC and DM-PCA on the Brekdown of 

Organic Matter in Litter Bags in the Field: Amended Final Report. Project Number: 

36121081, 36121081/OCR. Unpublished study prepared by Institut fuer Biologische 

Analytik und Consulting IBACON. 7 p. 

47615225 Gallagher, S.; Kendall, T.; Krueger, H. (2008) Penthiopyrad (DPX-LEM17) 200 g/L 

SC: A 96-Hour Static Acute Toxicity Test with the Rainbow Trout (Oncorhynchus 

mykiss). Project Number: DUPONT/19760, 112A/222, DUPONT/19760/OCR. 

Unpublished study prepared by Wildlife International, Ltd. 46 p. 

47615226 Gallagher, S.; Kendall, T.; Krueger, H. (2007) Penthiopyrad (DPX-LEM17) 200 g/L 

SC: A 48-Hour Static Acute Toxicity Test with the Cladoceran (Daphnia magna). 

Project Number: DUPONT/22839, 112A/221, DUPONT/22839/OCR. Unpublished 

study prepared by Wildlife International, Ltd. 46 p. 

47615227 Gallagher, S.; Kendall, T.; Kruegar, H. (2009) Penthiopyrad (DPX-LEM17) 200 g/L 

SC: A 48-Hour Static Acute Toxicity Test with the Cladoceran (Daphnia magna). 

Project Number: DUPONT/25552, 112A/251, DUPONT/25552/OCR. Unpublished 

study prepared by Wildlife International, Ltd. 47 p. 

47615228 Gallagher, S.; Kendall, T.; Krueger, H. (2009) Penthiopyrad (DPX-LEM17) 200 g/L 

SC: A 48-Hour Static Acute Toxicity Test with the Fed Cladoceran (Daphnia 

magna). Project Number: DUPONT/28095, 112A/292, DUPONT/28095/OCR. 

Unpublished study prepared by Wildlife International, Ltd. 46 p. 

47615229 Gallagher, S.; Kendall, T.; Krueger, H. (2009) Penthiopyrad (DPX-LEM17) 200 g/L 

SC: A 48-Hour Static Acute Toxicity Test with the Cladoceran (Daphnia magna) 

with Mixed Ages. Project Number: DUPONT/28096, 112A/293, 

DUPONT/28096/OCR. Unpublished study prepared by Wildlife International, Ltd. 

52 p. 
118

MRID Citation

47615230 Porch, J.; Kendall, T.; Krueger, H. (2008) Penthiopyrad (DPX-LEM17) 200 g/L SC: 

A 72-Hour Toxicity Test with the Freshwater Alga (Pseudokirchneriella subcapitata). 

Project Number: DUPONT/19759, 112A/223, DUPONT/19759/OCR. Unpublished 

study prepared by Wildlife International, Ltd. 62 p. 

47615231 Gallahger, S.; Kendall, T.; Krueger, H. (2009) Penthiopyrad (DPX-LEM17) 200 g/L 

SC: A 96-Hour Static Acute Toxicity Test with the Saltwater Mysid (Americamysis 

bahia). Project Number: DUPONT/27154, 112A/278, DUPONT/27154/OCR. 

Unpublished study prepared by Wildlife International, Ltd. 42 p. 

47615232 Gallagher, S.; Kendall, T.; Krueger, H. (2009) Penthiopyrad (DPX-LEM17) 200 g/L 

SC: A 96-Hour Static Acute Toxicity Test with the Sheepshead Minnow (Cyprinodon 

variegatus). Project Number: DUPONT/27153, 112A/279A, DUPONT/27153/OCR. 

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

47615233 Gallagher, S.; Kendall, T.; Krueger, H. (2009) Penthiopyrad (DPX-LEM17) 200 g/L 

SC: A 96-Hour Shell Deposition Test with the Eastern Oyster (Crassostrea virginica). 

Project Number: DUPONT/27155, 112A/280, DUPONT/27155/OCR. Unpublished 

study prepared by Wildlife International, Ltd. 49 p. 

47615234 Minderhout, T.; Kendall, T.; Krueger, H. (2009) Penthiopyrad (DPX-LEM17) 200 

g/L SC: A 48-Hour Static Acute Toxicity Test with the Mayfly (Centroptilum 

triangulifer). Project Number: DUPONT/26632, 112A/290, DUPONT/26632/OCR. 

Unpublished study prepared by Wildlife International, Ltd. 48 p. 

47615235 Minderhout, T.; Kendall, T.; Krueger, H. (2009) Penthiopyrad (DPX-LEM17) 200 

g/L SC: A 48-Hour Static Acute Toxicity Test with Caddisflies (Chimarra atternima). 

Project Number: DUPONT/26633, 112A/289, DUPONT/26633/OCR. Unpublished 

study prepared by Wildlife International, Ltd. 50 p. 

47615236 Gallagher, S.; Claude, M.; Kendall, T.; et al. (2009) Penthiopyrad (DPX-LEM17) 

200 g/L SC: A Semi-Static Life-Cycle Toxicity Test with the Cladoceran (Daphnia 

magna). Project Number: DUPONT/26161, 112A/261, DUPONT/26161/OCR. 

Unpublished study prepared by Wildlife International, Ltd. 73 p. 

47615237 Warmers, C. (2007) Penthiopyrad (DPX-LEM17) 200 g/L SC: Acute Oral and 

Contact Toxicity to the Honey Bee, Apis mellifera L.: Final Report. Project Number: 

DUPONT/21548, 20071176/01/BLEU, DUPONT/21548/OCR. Unpublished study 

prepared by Eurofins - GAB GmbH. 36 p. 

47615238 Hernadi, D. (2008) Penthiopyrad (DPX-LEM17) 200 g/L SC: A Laboratory Test to 

Evaluate the Effects on the Predatory Mite Typhlodromus pyri (Acari, Phytoseiidae): 

Final Report. Project Number: DUPONT/19757, 07/448/335RA, 

DUPONT/19757/OCR. Unpublished study prepared by LAB Research, Ltd. 38 p. 
119

MRID Citation

47615239 Hernaldi, D. (2008) Penthiopyrad 200 g/L SC (DPX-LEM17-063): A Laboratory 

Test to Study the Effects on the Parasitoid Aphidius rhopalosiphi (Hymenoptera, 

Braconidae): Final Report. Project Number: DUPONT/19758, 07/448/335FD, 

DUPONT/19758/OCR. Unpublished study prepared by LAB Research, Ltd. 45 p. 

47615240 Adelberger, I. (2008) Penthiopyrad (DPX-LEM17) 200 g/L SC: An Extended 

Laboratory Rate Response Test to Study the Effects on the Predatory Mite, 

Typhlodromus pyri (Acari, Phytoseiidae): Final Report. Project Number: 

DUPONT/25383, S08/01791, DUPONT/25383/OCR. Unpublished study prepared by 

Eurofins - GAB GmbH. 38 p. 

47615241 Klug, T. (2008) Penthiopyrad (DPX-LEM17) 220 g/L SC: An Extended Laboratory 

Rate Response Test to Study the Effects on the Predatory Bug Orius laevigatus 

Fieber (Heteroptera, Anthocoridae): Final Report. Project Number: DUPONT/25384, 

S08/01793, DUPONT/25384/OCR. Unpublished study prepared by Eurofins - GAB 

GmbH. 48 p. 

47615242 Klug, T. (2008) Penthiopyrad (DPX-LEM17) 200 g/L SC: An Extended Laboratory 

Rate Response Test to Study the Effects on the Green Lacewing, Chrysoperla carnea 

steph. (Chrysopidae, Neuroptera): Final Report. Project Number: 

DUPONT/25385/REVISION/1, S08/01792, DUPONT/25385/OCR. Unpublished 

study prepared by Eurofins - GAB GmbH. 43 p. 

47615243 Lehmhus, J. (2009) DPX-LEM17 20SC: A Field Study to Evaluate Effects on 

Predatory Mites (Acari-Phytoseiidae) in Apple Orchards in Germany and in Grape 

Vineyards in Italy, 2008: Final Report. Project Number: DUPONT/25551, 

S08/01756, DUPONT/25551/OCR. Unpublished study prepared by Eurofins - GAB 

GmbH. 68 p. 

47615244 Vertesi, A. (2007) Penthiopyrad (DPX-LEM17) 200 g/L SC: Acute Toxicity to the 

Earthworm, Eisenia fetida in Artificial Soil: Amended Final Report. Project Number: 

DUPONT/19762/REVISION/1, 07/448/125G, 17233. Unpublished study prepared by 

LAB Research, Ltd. 34 p. 

47615245 Vertesi, A. (2008) Penthiopyrad (DPX-LEM17) 200 g/L SC: Effects on 

Reproduction and Growth of the Earthworm, Eisenia fetida, in Artificial Soil: Final 

Report. Project Number: DUPONT/19763, 07/448/211G, DUPONT/19763/OCR. 

Unpublished study prepared by LAB Research, Ltd. 48 p. 

47615246 Stabler, D. (2007) Penthiopyrad (DPX-LEM17) 200 g/L SC: Assessment of the 

Effects on Soil Microflora: Final Report. Project Number: DUPONT/21549, 

20071176/01/ABMF, DUPONT/21549/OCR. Unpublished study prepared by 

Eurofins - GAB GmbH. 41 p. 
120

MRID Citation

47615248 Zaucha, T. (2009) Product Identity and Composition of End-Use Product 

Penthiopyrad (DPX-LEM17) 200 g/L SC. Project Number: DUPONT/22438, 

DUPONT/22438/OCR. Unpublished study prepared by E.I. du Pont de Nemours and 

Company. 76 p. 

47615249 Hubbard, P.; Beavers, J. (2009) Penthiopyrad (LEM17) 200 g/L SC: An Acute Oral 

Toxicity Study with the Northern Bobwhite (Colinus virginianus). Project Number: 

DUPONT/27842, 112/639, DUPONT/27842/OCR. Unpublished study prepared by 

Wildlife International, Ltd. 55 p. 

47615335 Gallagher, S.; Kendall, T.; Krueger, H. (2009) Penthiopyrad (DPX-LEM17) 200 g/L 

EC: A 96-Hour Static Acute Toxicity Test with the Fathead Minnow (Pimephales 

promelas) . Project Number: 112A/309, DUPONT/29168. Unpublished study 

prepared by Wildlife International, Ltd. 46 p. 

47615336 Gallagher, S.; Kendall, T.; Krueger, H. (2009) Penthiopyrad (DPX-LEM17) 200 g/L 

EC: A 48-Hour Static Acute Toxicity Test with the Cladoceran (Daphnia magna). 

Project Number 112A/257A, DUPONT/25537. Unpublished study prepared by 

Wildlife International, Ltd. 46 p. 

47615337 Jeyalakshmi, T. (2009) Penthiopyrad (DPX-LEM17) 200 g/L EC: Acute Oral and 

Contact Toxicity to the Honey Bee, Apis mellifera L. Project Number: 08205, 

DUPONT/25529. Unpublished study prepared by International Institute of 

Biotechnology and Toxicology. 47 p. 

47615338 Moll, M. (2008) Penthiopyrad (DPX-LEM17) 200 g/L EC: A Laboratory Test to 

Study the Effects on the Parasitoid Aphidius rhopalosiphi (Hymenoptera, 

Braconidae). Project Number: 43481001, DUPONT/25522. Unpublished study 

prepared by Institut fuer Biologische Analytik und Consulting IBACON. 40 p. 

47615339 Moll, M. (2008) Penthiopyrad (DPX-LEM17) 200 g/L EC: A Laboratory Test to 

Evaluate the Effects on the Predatory Mite, Typhlodromus pyri (Acari, Phytoseiidae). 

Project Number 43482063, DUPONT/25523. Unpublished study prepared by Institut 

fuer Biologische Analytik und Consulting IBACON. 34 p. 

47615340 Moll, M. (2009) Penthiopyrad (DPX-LEM17) 200 g/L EC: An Extended Laboratory 

Rate Response Test to Study the Effects on the Predatory Mite, Typhlodromus pyri 

(Acari, Phytoseiidae). Project Number: DUPONT/25381, 43483062. Unpublished 

study prepared by Institut fuer Biologische Analytik und Consulting IBACON. 46 p. 

47615341 Moll, M. (2009) Penthiopyrad (DPX-LEM17) 200 g/L EC: An Extended Laboratory 

Rate Response Test to Study the Effects on the Predatory Bug Orius Laevigatus 

Fieber (Heteroptera, Anthocoridae). Project Number: DUPONT/25386, 43485052. 

Unpublished study prepared by Institut fuer Biologische Analytik und Consulting 

IBACON. 43 p. 
121

MRID Citation

47615342 Moll, M. (2009) Penthiopyrad (DPX-LEM17) 200 g/L EC: An Extended Laboratory 

Rate Response Test to Study the Effects on the Green Lacewing, Chrysoperla carnea 

Steph (Chrysophidae, Neuroptera). Project Number: DUPONT/25387, 43484047. 

Unpublished study prepared by Institut fuer Biologische Analytik und Consulting 

IBACON. 44 p. 

47615343 Stabler, D. (2009) Penthiopyrad (DPX-LEM17) 200 g/L EC: Assessment of the 

Effects on Soil Microflora. Project Number: S08/01794, DUPONT/25532. 

Unpublished study prepared by Eurofins - GAB GmbH. 41 p. 

47737323 Gallagher, S.; Kendall, T.; Krueger, H. (2009) Chlorothalonil/Penthiopyrad (DPXQFA61) SC (250 g/L:100 g/L): A 96-Hour Static Acute Toxicity Test with the 

Rainbow Trout (Oncorhynchus mykiss). Project Number: DUPONT/25536, 

DUPONT/25536/OCR, 112A/253. Unpublished study prepared by Wildlife 

International, Ltd. 51 p. 

47737324 Gallagher, S.; Kendall, T.; Krueger, H. (2009) Chlorothalonil/Penthiopyrad (DPXQFA61) SC (250 g/L:100 g/L): A 48-Hour Static Acute Toxicity Test with the 

Cladoceran (Daphnia magna). Project Number: DUPONT/25538, 

DUPONT/25538/OCR, 112A/252. Unpublished study prepared by Wildlife 

International, Ltd. 52 p. 

47737325 Porch, J.; Kendall, T.; Krueger, H. (2009) Chlorothalonil/Penthiopyrad (DPXQFA61) SC (250 g/L:100 g/L): A 72-Hour Toxicity Test with the Freshwater Alga 

(Pseudokirchneriella subcapitata). Project Number: DUPONT/25534, 

DUPONT/25534/OCR, 112A/249. Unpublished study prepared by Wildlife 

International, Ltd. 62 p. 

47737326 Jeyalakshmi, T. (2009) Chlorothalonil/Penthiopyrad (DPX-QFA61) SC (250 g/L:100 

g/L): Acute Oral and Contact Toxicity to the Honey Bee, Apis mellifera L.. Project 

Number: DUPONT/24930, DUPONT/24930/OCR, 08279. Unpublished study 

prepared by International Institute of Biotechnology and Toxicology . 37 p. 

47737327 Moll, M. (2008) Chlorothalonil/Penthiopyrad (DPX-QFA61) SC (250 g/L:100 g/L): 

A Laboratory Test to Study the Effects on the Parasitoid Aphidius rhopalosiphi 

(Hymenoptera, Braconidae). Project Number: DUPONT/24931, 

DUPONT/34931/OCR, 43471001. Unpublished study prepared by Institut fuer 

Biologische Analytik und Consulting IBACON. 40 p. 

47737328 Moll, M. (2008) Chlorothalonil/Penthiopyrad (DPX-QFA61) SC (250 g/L:100 g/L): 

A Laboratory Test to Evaluate the Effects on the Predatory Mite, Typhlodromus pyri 

(Aacari, Phytoseiidae): Final Report. Project Number: DUPONT/25524, 

DUPONT/25524/OCR, 43472063. Unpublished study prepared by Institut fuer 

Biologische Analytik und Consulting IBACON. 33 p. 
122

MRID Citation

47737329 Moll, M. (2009) Chlorothalonil/Penthiopyrad (DPX-QFA61) SC (250 g/L:100 g/L): 

An Extended Laboratory Test to Evaluate the Effects on the Predatory Mite, 

Typhlodromus pyri (Acari, Phytoseiidae): Final Report. Project Number: 

DUPONT/25382, DUPONT/25382/OCR, 43473062. Unpublished study prepared by 

Institut fuer Biologische Analytik und Consulting IBACON. 50 p. 

47737330 Moll, M. (2009) Chlorothalonil/Penthiopyrad (DPX-QFA61) SC (250 g/L:100 g/L): 

An Extended Laboratory Test to Evaluate the Effects on the Lacewing, Chrysoperla 

carnea (Neuroptera: Chrysopidae): Final Report. Project Number: DUPONT/25389, 

DUPONT/25389/OCR, 43474047. Unpublished study prepared by Institut fuer 

Biologische Analytik und Consulting IBACON. 44 p. 

47737331 Moll, M. (2009) Chlorothalonil/Penthiopyrad (DPX-QFA61) SC (250 g/L:100 g/L): 

An Extended Laboratory Test to Evaluate the Effects on the Predatory Bug, Orius 

laevigatus (Heteroptera, Anthocoridae): Final Report. Project Number: 

DUPONT/25388, DUPONT/25388/OCR, 43475052. Unpublished study prepared by 

Institut fuer Biologische Analytik und Consulting IBACON. 40 p. 

47737332 Luhrs, U. (2008) Chlorothalonil/Penthiopyrad (DPX-QFA61) SC (250 g/L: 100 g/L): 

Acute Toxicity to the Earthworm, Eisenia fetida in Artificial Soil with 5% Peat. 

Project Number: DUPONT/25540, DUPONT/25540/OCR, 43476021. Unpublished 

study prepared by Institut fuer Biologische Analytik und Consulting IBACON. 31 p. 

47737333 Luhrs, U. (2008) Chlorothalonil/Penthiopyrad (DPX-QFA61) SC (250 g/L : 100 

g/L): Effects on Reproduction and Growth of the Earthworm, Eisenia fetida, in 

Artificial Soil with 5% Peat: Final Report. Project Number: DUPONT/25541, 

DUPONT/25541/OCR, 43477022. Unpublished study prepared by Institut fuer 

Biologische Analytik und Consulting IBACON. 41 p. 

47737334 Feil, N. (2009) Chlorothalonil/Penthiopyrad (DPX-QFA61) SC (250 g/L:100 g/L): 

Assessment of the Effects on Soil Microflora. Project Number: 

DUPONT/25533/REVISION/2, DUPONT/25533/REVISION/2/OCR, 43478080. 

Unpublished study prepared by Institut fuer Biologische Analytik und Consulting 

IBACON. 46 p. 

 6.3. Chlorothalonil Ecotoxicity Studies Discussed (Previously Submitted) 

Davies PE, and White RWG. 1985. The Toxicology and Metabolism of Chlorothalonil in Fish. I. 

Lethal Levels for Salmo gairdneri, Galaxias maculates, G. truttaceus and G. auratus and 

the Fate of 14C-TCIN in S. gairdneri. Aquat Toxicol 7(1/2):93-105. 

Mezcua, M., Hernando, M.D., Piedra, L., Aguera, A., Fernandez-Alba, A.R. 2002. 

Chromatography-Mass Spectometry and Toxicity Evaluation of Selected Contaminants in 

Seawater. Chromatographia 56(3/4):199-205. 
123

MRID 45710221 Douglas, M. (1992) The Acute Toxicity of Chlorothalonil to Daphnia magna: 

 Lab Project Number: VCM 8(A)/920231. Unpublished study prepared by Huntingdon 

 Research Centre Ltd. 24 p. 

MRID 42432801 Hughes, J.; Williams, T. (1992) The Toxicity of Technical Chlorothalonil 

 Fungicide to Selenaestrum capricornutum: Lab Project Number: B038-001-1. 

 Unpublished study prepared by Malcolm Pirnie, Inc. 37 p. 

MRID 00077759 Atkins, E.L., Jr. and L.D. Anderson (1969) Effect of Pesticides on 

 Apiculture: Project No. 1499; Research Report CF-4863. Annual Report Oct 1968. 

 (Unpublished Study Received Mar 16, 1970 under 0F0961; Prepared by Univ. of 

 California-Riverside, Dept. of Entomology, Submitted by Nor-Am Agricultural Products, 

 Inc. Naperville, Ill.; CDL: 093272-B).
124

Appendix A. STIR v.1.0 (Screening Tool for Inhalation Risk) Input/Output 

The Screening Tool for Inhalation Risk (STIR v.1.0, November 19, 2010) was used to calculate 

an upper bound estimate of exposure using penthiopyrad’s vapor pressure and molecular weight 

for vapor phase exposure as well as the maximum application rate and method of application for 

spray drift. STIR incorporates results from several toxicity studies including acute oral and 

inhalation rat toxicity endpoints obtained from the “six-pack” of core studies, which are a series 

of six guideline studies that are submitted to the Registration Division of the Office of Pesticide 

Programs for technical and formulated products of a pesticide (LD50 >2000 mg/kg bw and LC50

>5.59 mg/L air, respectively) as well as the most sensitive acute oral avian toxicity endpoint 

(Northern bobwhite quail LD50 >2250 mg/kg bw). Based on the results of the STIR model, 

inhalation exposure alone was not determined to be a potential pathway of concern for avian 

and/or mammalian species on an acute basis. 

Inhalation exposure via spray drift and vapor-phase of the pesticide alone do not appear to be of 

concern. The analysis of the inhalation route of in STIR does not consider that aggregation with 

other exposure pathways such as dietary, dermal, or drinking water may contribute to a total 

exposure that has a potential for effects to non-target animals. However, the Agency does 

consider the relative importance of other routes of exposure in situations where data indicate that 

pesticide exposures through other routes may be potentially significant contributors to wildlife 

risk (USEPA, 2004). 

Screening Tool for Inhalation Risk 

This tool is designed to provide the risk assessor with a rapid method for determining the 

potential significance of the inhalation exposure route to birds and mammals in a risk 

assessment. 

 

Input 

Application and Chemical Information 

Enter Chemical Name Penthiopyrad 

Enter Chemical Use turf 

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

If Spray What Type (enter ground or air) air 

Enter Chemical Molecular Weight (g/mole) 359.42 

Enter Chemical Vapor Pressure (mmHg) 2.20E-08 

Enter Application Rate (lb a.i./acre) 0.95 

Toxicity Properties 

Bird 

Enter Lowest Bird Oral LD50 (mg/kg bw) 2250 

Enter Mineau Scaling Factor 1.15 

Enter Tested Bird Weight (kg) 0.178 

Mammal 

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

Enter Lowest Rat Inhalation LC50 (mg/L) 5.59 

Duration of Rat Inhalation Study (hrs) 4 

Enter Rat Weight (kg) 0.224 

 
125

Output 

Results Avian (0.020 kg ) 

Maximum Vapor Concentration in Air at Saturation (mg/m3) 4.26E-04 

Maximum 1-hour Vapor Inhalation Dose (mg/kg) 5.35E-05 

Adjusted Inhalation LD50 5.48E+01 

Ratio of Vapor Dose to Adjusted Inhalation LD50 9.76E-07 Exposure not Likely Significant 

Maximum Post-treatment Spray Inhalation Dose (mg/kg) 9.13E-02 

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD50 1.67E-03 Exposure not Likely Significant 

 

Results Mammalian (0.015 kg ) 

Maximum Vapor Concentration in Air at Saturation (mg/m3) 4.26E-04 

Maximum 1-hour Vapor Inhalation Dose (mg/kg) 6.72E-05 

Adjusted Inhalation LD50 4.65E+02 

Ratio of Vapor Dose to Adjusted Inhalation LD50 1.45E-07 Exposure not Likely Significant 

Maximum Post-treatment Spray Inhalation Dose (mg/kg) 1.15E-01 

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD50 2.47E-04 Exposure not Likely Significant 
126

Appendix B. Chemical Names, Structures, and Maximum Reported Amounts of PenthiopyDegradates. Table B.1. Penthiopyrad and Its Environmental Degradates. 

Code Name (Mitsui, DuPont) Chemical Name Chemical Structure Study Type MRID Maxim

%AR (

PARENT

Penthiopyrad MTF-753 DPX-LEM17 

IUPAC: (RS)-N-[2-(1,3-dimethylbutyl)-3-thienyl]-1-methyl-3-(trifluoromethyl)-pyrazole-4-carboxamide CAS: N-[2-(1,3-dimethylbutyl)-3-thienyl]-1-methyl-3-(trifluoromethyl)-1H-pyrazole-4-carboxamide (9CI) CAS-no: 183675-82-3 Formula: C16H20F3N3OS 

MW: 359.42 g/mol 

Aerobic soil metabolism (MRID 47614959-61, -63) Anaerobic soil metabolism (MRID 4761496Soil photolysis (MRID 47614965) Aqueous photolysis (MRID 47614839) Hydrolysis (MRID 47614837, 47614838) Anaerobic aquatic metabolism (MRID 476Aerobic aquatic metabolism (MRID 476149Terrestrial field dissipation (MRID 476151-63, -64, -65, -66, -67, -72, -73) 

DEGRADATES 

753-T-DO IN-PGH58 

(RS)-N-[5-hydroxy-5-(1,3-dimethylbutyl)-2-oxo-2,5-dihydrothiophen-4-yl]-1-methyl3-trifluoromethyl-1H-pyrazole-4-carboxamide Formula: C16H20F3N3O3S 

MW: 391.41 g/mol 

Aerobic soil 47614959 8.1 (1Anaerobic soil 47614964 4.5 (Anaerobic aquatic 47614976 0.9 (Aerobic aquatic 47614975 2.3 (1Field studies 47615172 1.5 (5
127

Code Name (Mitsui, DuPont) Chemical Name Chemical Structure Study Type MRID Maxim

%AR (

753-F-DO IN-PGH59 

(RS)-N-[5-hydroxy-5-(1,3-dimethylbutyl)-2-oxo-2,5-dihydrofuran-4-yl]-1-methyl-3-trifluoromethyl-1H-pyrazole-4-carboxamide Formula: C16H20F3N3O4

MW: 486.83 g/mol 

Aerobic soil 47614961 4.4 (9Anaerobic soil 47614964 5.8 (Soil photolysis 47614965 7.4 (1Aerobic aquatic 47614975 1.9 (1Field studies 47615162 <3 (0-3

753-A-OH IN-PGH53 

(RS)-N-[2-(3-hydroxy-1,3-dimethyl-butyl)thiophen-3-yl]-1-methyl-3-trifluoromethyl-1Hpyrazole-4-carboxamide Formula: C16H20F3N3O2S 

MW: 375.42 g/mol 

Aerobic soil 47614959 7.2 (6Anaerobic soil 47614964 0.8 (Aerobic aquatic 47614975 7.5 (1Field studies 47615173 2.0 (4

753-A-OH isomer M12 

(RS)-N-[2-(1-hydroxymethyl-1,3-dimethylbutyl)thiophen-3-yl]-1-methyl-3-trifluoromethyl-1Hpyrazole-4-carboxamide Formula: C16H20F3N3O2S 

MW: 375.42 g/mol 

Aerobic soil 47614959 4.3 (1

753-A-COOH isomer M11 

(RS)-3-methyl-1-{3-[(1-methyl3-trifluoromethyl-1H-pyrazole-4-carbonyl)amino]thiophen-2-yl}pentanoic acid Formula: C16H18F3N3O3S 

MW: 389.40 g/mol 

Aerobic soil 47614959 5.4 (1

DM-753 IN-PGH60 

(RS)-N-[2-(1,3-dimethylbutyl)thiophen-3-yl]-3-trifluoromethyl-1H-pyrazole-4-carboxamide Formula: C15H18F3N3OS 

MW: 345.39 g/mol 

Anaerobic aquatic 47614976 1.1 (
128

Code Name (Mitsui, DuPont) Chemical Name Chemical Structure Study Type MRID Maxim

%AR (

PAM IN-PGH45 

1-methyl-3-trifluoromethyl-1Hpyrazole-4-carboxamide Formula: C6H6F3N3O MW: 193.13 g/mol 

Aerobic soil 47614961 3.9 (9Anaerobic soil 47614964 3.9 (14Soil photolysis 47614965 48 B (Anaerobic aquatic 47614976 2.7 (Aerobic aquatic 47614975 2.7 (1Field studies 47615164 24 (2

PCA IN-MR507 

1-methyl-3-trifluoromethyl-1Hpyrazole-4-carboxylic acid CAS-no: 113100-53-1Formula: C6H5F3N2O2

MW: 194.11 g/mol 

Aerobic soil 47614959 3.0 (1Anaerobic soil 47614964 2.8 (1Soil photolysis 47614965 41 B Anaerobic aquatic 47614976 1.3 (1Aerobic aquatic 47614975 11.9 (1Field studies 47615166 11 (3

DM-PCA IN-DRJ75 

3-trifluoromethyl-1H-pyrazole-4- carboxylic acid CAS-no: 543739-84-0 Formula: C5H3F3N2O2

MW: 180.08 g/mol 

Aerobic soil 47614959 28 (1Anaerobic soil 47614964 7.1 (1Anaerobic aquatic 47614976 2.5 (1Aerobic aquatic 47614975 5.4 (1Field studies 47615162 25 (12

Unextracted Residues 

(N/A) 

(N/A) 

Aerobic soil 47614959 40 (1Anaerobic soil 47614964 33 (5Soil photolysis 47614965 13-26 B Anaerobic aquatic 47614976 3.3 (1Aerobic aquatic 47614975 14.1 (1

Carbon dioxide Carbon dioxide 

Formula: CO2

MW: 44.1 g/molSMILES: O=C=O 

O O

Aerobic soil 47614961 26 (3

Anaerobic soil 47614964 5.4 (1Soil photolysis 47614965 26-52 B Anaerobic aquatic 47614976 0.6 (1Aerobic aquatic 47614975 8.8 (1

A nd means “not detected.” LOD means “limit of detection.” B Reported values of %AR for the soil photolysis study are 2x raw values for PAM and PCA due to mixing of radiolabels in the applied test compoun

unextracted residues, %AR values for this study are ranges of 1-2x the raw values, the latter of which represent the mean of values that would result fr

compound. 
129

Figure B.1. Environmental Transformation Route of Penthiopyrad (MRID 48081904, p 

84). 
130

Appendix C. Aquatic Model Input/Output Data. 

Table C-1. Summary of Model Input Files. 

File name Date 

Input/Output File for SCI-GROW 

Penthiopyrad_eco.sci Aug. 8, 2011 

Input Files for PRZM/EXAMS 

Alfa-NC-Jul15.pzr 

Sep. 14, 2011 

Bean-IL-Jul15.pzr 

Berr-FL-Jan15.pzr 

Bulb-STX-Feb21.pzr 

Cabb-STX-Feb21.pzr 

Cano-ND-Jun1.pzr Sep. 27, 2011 

Corn-TX-Jul15.pzr 

Sep. 14, 2011 

Cott-MS-Aug1.pzr 

Cucu-STX-Apr1.pzr 

Frui-FLpep-Nov1.pzr 

Leaf-CAlet-Apr15.pzr 

Legu-MS-Sep15.pzr 

Nuts-OR-Oct1.pzr 

Orna-CAres-Apr1.pzr 

Pean-NC-Aug29.pzr 

Pome-PA-Jun1.pzr 

Pota-FL-Mar1.pzr 

Root-FL-Nov1.pzr 

Sorg-KS-Aug15.pzr 

Ston-MI-Jun15.pzr 

Suga-MN-Aug1.pzr 

Sunf-ND-Jun15.pzr 

Turf-CA-Nov1.pzr 

Whea-TX-Apr1.pzr 

Input Files for PFAM 

WIcran6.PFA Sep. 22, 2011 

Input/Output Files for KABAM 

KABAM_penthiopyrad_9-19-11.xls Sep. 19, 2011 

KABAM_penthiopyrad_lowEECs_9-19-11.xls Sep. 19, 2011 

Input files attached: 

Penthiopyrad_eco.sci

Penthiopyrad PE 

files.zip

WIcran6.PFA KABAM_penthiopyra

d_9-19-11.xls

KABAM_penthiopyra

d_lowEECs_9-19-11.x
131

Example Input/Output Data for Individual Simulations 

SCI-GROW Input/Output File 

 SciGrow version 2.3 

 chemical:Penthiopyrad 

 time is 8/ 8/2011 19:46:24 

 ------------------------------------------------------------------------ 

 Application Number of Total Use Koc Soil Aerobic 

 rate (lb/acre) applications (lb/acre/yr) (ml/g) metabolism (days) 

 ------------------------------------------------------------------------ 

 0.950 3.0 2.850 7.30E+02 140.0 

 ------------------------------------------------------------------------ 

 groundwater screening cond (ppb) = 4.87E-01 

 ************************************************************************ 

PRZM/EXAMS Example Input/Output File 

stored as Legu-MS-Sep15.out 

Chemical: Penthiopyrad 

PRZM environment: MSsoybeanSTD.txt modified Tueday, 26 August 2008 at 06:16:40 

EXAMS environment: pond298.exv modified Tueday, 26 August 2008 at 06:14:08 

Metfile: w03940.dvf modified Tueday, 26 August 2008 at 06:14:14 

Water segment concentrations (ppb) 

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly 

1961 17.22 16.92 16.21 13.43 9.578 2.44 

1962 15.31 15.11 14.52 13.52 12.99 11.12 

1963 18.35 18.12 17.78 14.74 13.48 11.77 

1964 37.94 37.41 34.92 31.77 31.54 18.84 

1965 30.97 30.8 30.2 29.35 28.88 25.46 

1966 27.29 27.18 26.85 26.41 26.05 23.62 

1967 26.13 25.98 25.25 23.66 23.4 21.73 

1968 25.38 25.29 25.09 24.53 24.18 21.72 

1969 25.35 24.58 23.7 21.71 21.49 19.78 

1970 38.18 37.65 35.95 34.14 32.59 24.03 

1971 36.72 36.38 35.26 31.01 30.01 27.8 

1972 33.86 33.74 33.36 32.43 31.87 28.67 

1973 29.63 29.57 29.32 28.84 28.47 25.86 

1974 29.47 29.32 28.59 27.68 27.22 25.31 

1975 51.38 50.48 47.43 44.14 40.2 28.58 

1976 39.18 39.07 38.56 37.66 37.08 33.48 

1977 37.92 37.65 36.75 34.18 33.06 30.48 

1978 36.55 36.32 35.49 33.96 33.53 30.83 

1979 45.5 45.1 43.85 40.54 38.4 33.25 

1980 41.6 41.43 41.12 40.34 39.75 35.3 

1981 36.66 36.32 35.15 33.78 33.34 30.79 

1982 44.15 43.79 42.77 40.11 39.82 31.59 

1983 42.6 42.24 41.77 39.16 38.57 35.17 

1984 46.37 45.93 44.17 43.04 40.39 35.89 

1985 40.46 40.37 40.03 39.55 39.09 35.31 
132

1986 35.39 35.25 34.68 34.22 33.54 31.23 

1987 33.39 33.31 33.03 32.51 32.14 29.05 

1988 33.32 33.1 32.75 32.05 31.79 28.12 

1989 38.45 38.08 37.34 35.92 34.06 29.19 

1990 35.79 35.68 35.34 34.63 34.06 30.12 

Sorted results 

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly 

0.032258064516129 51.38 50.48 47.43 44.14 40.39 35.89 

0.0645161290322581 46.37 45.93 44.17 43.04 40.2 35.31 

0.0967741935483871 45.5 45.1 43.85 40.54 39.82 35.3 

0.129032258064516 44.15 43.79 42.77 40.34 39.75 35.17 

0.161290322580645 42.6 42.24 41.77 40.11 39.09 33.48 

0.193548387096774 41.6 41.43 41.12 39.55 38.57 33.25 

0.225806451612903 40.46 40.37 40.03 39.16 38.4 31.59 

0.258064516129032 39.18 39.07 38.56 37.66 37.08 31.23 

0.290322580645161 38.45 38.08 37.34 35.92 34.06 30.83 

0.32258064516129 38.18 37.65 36.75 34.63 34.06 30.79 

0.354838709677419 37.94 37.65 35.95 34.22 33.54 30.48 

0.387096774193548 37.92 37.41 35.49 34.18 33.53 30.12 

0.419354838709677 36.72 36.38 35.34 34.14 33.34 29.19 

0.451612903225806 36.66 36.32 35.26 33.96 33.06 29.05 

0.483870967741936 36.55 36.32 35.15 33.78 32.59 28.67 

0.516129032258065 35.79 35.68 34.92 32.51 32.14 28.58 

0.548387096774194 35.39 35.25 34.68 32.43 31.87 28.12 

0.580645161290323 33.86 33.74 33.36 32.05 31.79 27.8 

0.612903225806452 33.39 33.31 33.03 31.77 31.54 25.86 

0.645161290322581 33.32 33.1 32.75 31.01 30.01 25.46 

0.67741935483871 30.97 30.8 30.2 29.35 28.88 25.31 

0.709677419354839 29.63 29.57 29.32 28.84 28.47 24.03 

0.741935483870968 29.47 29.32 28.59 27.68 27.22 23.62 

0.774193548387097 27.29 27.18 26.85 26.41 26.05 21.73 

0.806451612903226 26.13 25.98 25.25 24.53 24.18 21.72 

0.838709677419355 25.38 25.29 25.09 23.66 23.4 19.78 

0.870967741935484 25.35 24.58 23.7 21.71 21.49 18.84 

0.903225806451613 18.35 18.12 17.78 14.74 13.48 11.77 

0.935483870967742 17.22 16.92 16.21 13.52 12.99 11.12 

0.967741935483871 15.31 15.11 14.52 13.43 9.578 2.44 

0.1 45.365 44.969 43.742 40.52 39.813 35.287 

 Average of yearly averages: 26.551 

Inputs generated by pe5.pl - Novemeber 2006 

Data used for this run: 

Output File: Legu-MS-Sep15 

Metfile: w03940.dvf 

PRZM scenario: MSsoybeanSTD.txt 

EXAMS environment file: pond298.exv 

Chemical Name: Penthiopyrad 

Description Variable Name Value Units Comments 

Molecular weight mwt 359.4 g/mol 

Henry's Law Const. henry 7.6e-9 atm-m^3/mol 

Vapor Pressure vapr torr 

Solubility sol 1.4 mg/L 
133

Kd Kd mg/L 

Koc Koc 720 mg/L 

Photolysis half-life kdp 0 days Half-life 

Aerobic Aquatic Metabolism kbacw 287 days Halfife 

Anaerobic Aquatic Metabolism kbacs 0 days Halfife 

Aerobic Soil Metabolism asm 240 days Halfife 

Hydrolysis: pH 7 0 days Half-life 

Method: CAM 2 integer See PRZM manual 

Incorporation Depth: DEPI cm 

Application Rate: TAPP 0.44 kg/ha 

Application Efficiency: APPEFF 0.95 fraction 

Spray Drift DRFT 0.05 fraction of application rate applied to pond 

Application Date Date 15-09 dd/mm or dd/mmm or dd-mm or dd-mmm 

Interval 1 interval 7 days Set to 0 or delete line for single app. 

app. rate 1 apprate kg/ha 

Interval 2 interval 14 days Set to 0 or delete line for single app. 

app. rate 2 apprate 0.17 kg/ha 

Record 17: FILTRA 

 IPSCND 1 

 UPTKF 

Record 18: PLVKRT 

 PLDKRT 

 FEXTRC 0.5 

Flag for Index Res. Run IR EPA Pond 

Flag for runoff calc. RUNOFF none none, monthly or total(average of entire run) 

PFAM-VVWM Example Output File 

Variable Volume Water Model, Version 0.0 

 

 ******************************************* 

Performed on: 9/22/2011 at 17:29 

 Standard Reservoir 

 Chemical # 1 

 

Peak 1-in-10 = 2.98E+02 ppb 

Chronic 1-in-10 = 2.40E+02 ppb 

 

4-day avg 1-in-10 = 2.96E+02 ppb 

21-day avg 1-in-10 = 2.93E+02 ppb 

60-day avg 1-in-10 = 2.89E+02 ppb 

90-day avg 1-in-10 = 2.89E+02 ppb 

 

 YEAR Peak 4-day 21-day 60-day 90-day Yearly Avg 

 1 9.80E+01 9.69E+01 9.54E+01 9.47E+01 9.43E+01 6.98E+01 

 2 1.62E+02 1.61E+02 1.59E+02 1.57E+02 1.55E+02 1.26E+02 

 3 1.95E+02 1.94E+02 1.91E+02 1.87E+02 1.84E+02 1.56E+02 

 4 2.25E+02 2.24E+02 2.22E+02 2.18E+02 2.16E+02 1.76E+02 

 5 1.96E+02 1.94E+02 1.89E+02 1.86E+02 1.84E+02 1.67E+02 

 6 2.10E+02 2.09E+02 2.06E+02 2.04E+02 2.02E+02 1.64E+02 

 7 1.93E+02 1.90E+02 1.85E+02 1.79E+02 1.76E+02 1.54E+02 

 8 2.36E+02 2.35E+02 2.33E+02 2.30E+02 2.28E+02 1.92E+02 

 9 2.49E+02 2.47E+02 2.42E+02 2.41E+02 2.39E+02 2.16E+02 

 10 2.97E+02 2.95E+02 2.93E+02 2.90E+02 2.87E+02 2.49E+02 
134

 11 3.09E+02 3.08E+02 3.06E+02 3.04E+02 3.01E+02 2.76E+02 

 12 2.63E+02 2.61E+02 2.57E+02 2.60E+02 2.71E+02 2.00E+02 

 13 2.21E+02 2.20E+02 2.18E+02 2.17E+02 2.14E+02 1.78E+02 

 14 2.73E+02 2.70E+02 2.66E+02 2.64E+02 2.61E+02 2.08E+02 

 15 2.46E+02 2.44E+02 2.41E+02 2.40E+02 2.36E+02 2.10E+02 

 16 2.98E+02 2.96E+02 2.91E+02 2.80E+02 2.71E+02 2.30E+02 

 17 3.04E+02 3.02E+02 3.00E+02 2.97E+02 2.96E+02 2.41E+02 

 18 2.35E+02 2.34E+02 2.32E+02 2.28E+02 2.27E+02 1.88E+02 

 19 2.23E+02 2.22E+02 2.18E+02 2.14E+02 2.12E+02 1.84E+02 

 20 1.79E+02 1.78E+02 1.75E+02 1.71E+02 1.67E+02 1.40E+02 

 21 2.01E+02 1.99E+02 1.98E+02 1.95E+02 1.93E+02 1.66E+02 

 22 2.62E+02 2.61E+02 2.57E+02 2.55E+02 2.53E+02 2.30E+02 

 23 2.46E+02 2.44E+02 2.41E+02 2.40E+02 2.38E+02 1.97E+02 

 24 2.25E+02 2.24E+02 2.21E+02 2.20E+02 2.17E+02 1.85E+02 

 25 2.02E+02 2.00E+02 1.95E+02 1.92E+02 1.91E+02 1.81E+02 

 26 2.09E+02 2.07E+02 2.06E+02 2.04E+02 2.02E+02 1.75E+02 

 27 2.04E+02 2.04E+02 2.02E+02 1.99E+02 1.98E+02 1.72E+02 

 28 2.04E+02 2.03E+02 2.02E+02 1.98E+02 1.97E+02 1.75E+02 

 29 2.35E+02 2.33E+02 2.29E+02 2.24E+02 2.24E+02 1.86E+02 

 30 1.53E+02 1.51E+02 1.46E+02 1.37E+02 1.44E+02 1.70E+02 

 

 *********************************************************************** 

 Effective compartment halflives averaged over simulation duration: 

 

 washout halflife (days) = 228.8117 

 water col metab halflife (days) = 711.1456 

 hydrolysis halflife (days) = 1.0016146E+08 

 photolysis halflife (days) = 2.0871076E+10 

 volatile halflife (days) = 65048.11 

 total water col halflife (days) = 172.6528 

 

 zero burial 

 benthic metab halflife (days) = 1.7515901E+08 

 benthic hydrolysis halflife (days) = 7.8759188E+09 

 total benthic halflife (days) = 1.7134827E+08 

 *********************************************************************** 

 

 **************** Inputs ******************* 

 Chemical # 1 

 406.000000000000 

 Water Column System Halflife(except photo & hydrolysis = 

 100000000.000000 Benthic Compartment Halflife (except hydrolysis) = 

 100000000.000000 Photolysis Halflife = 

 100000000.000000 Hydrolysis Halflife = 

 359.400000000000 Molecular Wieght = 

 2.200000000000000E-008 Vapor Pressure = 

 1.40000000000000 Solubility = 

 720.000000000000 Koc = 

 20.0000000000000 Aerobic Reference Temper = 

 20.0000000000000 Anaerobic Reference Temper = 

 40.0000000000000 Reference Latitude = 

 55000.0000000000 Enthalpy of Henry = 

 20.0000000000000 Henry Reference Temperature 

 ****************** End of Run ************************ 
135

Appendix D. Example T-REX Output for Penthiopyrad. 

Table D.1. Dose- and Dietary-based Upper Bound Kenaga EECs and Chronic RQs Based 

on the Proposed Use of Penthiopyrad for Turf (0.95 lbs a.i./A) (Acute RQs were not 

calculated [NC] because non-definitive toxicity endpoints exist for birds and mammals) 

Table D.1.a. Upper Bound Kenaga, Chronic Avian Dietary Based Risk Quotients 

NOAEC (ppm) 

EECs and RQs 

Short Grass Tall Grass 

Broadleaf 

Plants/ 

Small Insects 

Fruits/Pods/ 

Seeds/ 

Large Insects 

EEC RQ EEC RQ EEC RQ EEC RQ 

1520 400.79 0.26 183.70 0.12 225.45 0.15 25.05 0.02 

Size class not used for dietary risk quotients 

Table D.1.b. Upper Bound Kenaga, Chronic Mammalian Dietary Based Risk 

Quotients 

NOAEC 

(ppm) 

EECs and RQs 

Short Grass Tall Grass 

Broadleaf 

Plants/ 

Small Insects 

Fruits/Pods/ 

Seeds/ 

Large Insects 

EEC RQ EEC RQ EEC RQ EEC RQ 

200 400.79 2.00 183.70 0.92 225.45 1.13 25.05 0.13 

Size class not used for dietary risk quotients 

Table D.1.c. Upper Bound Kenaga, Chronic Mammalian Dose-Based Risk Quotients 

Size 

Class 

(grams) 

Adjusted 

NOAEL 

EECs and RQs 

Short Grass Tall Grass 

Broadleaf 

Plants/ 

Small Insects 

Fruits/Pods/ 

Seeds/ 

Large Insects 

Granivore 

EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ 

15 19.05 382.12 20.06 175.14 9.19 214.94 11.28 23.88 1.25 5.31 0.28 

35 15.42 264.10 17.13 121.05 7.85 148.56 9.64 16.51 1.07 3.67 0.24 

1000 6.67 61.23 9.18 28.06 4.21 34.44 5.17 3.83 0.57 0.85 0.13 
136

Appendix E. Penthiopyrad Degradate Toxicity Summary. 

Table E.1. Freshwater Fish Acute Toxicity to Penthiopyrad Metabolites 

Test Species/ 

Test Substance 

(Flow-through/Static/ 

Static-renewal)

Purity 

(%) 

96-hour LC50 

(95% C.I.) 

(μg/L or mg/L, mean-measured)

Slope 

Toxicity 

Category MRID Study Classification

Rainbow Trout 

(Oncorhynchus mykiss) 

(DM-PCA); (Static) 

99.87 

LC50 > 99.19 mg/L 

Slope = NA Practically 

non-toxic 47614989 Acceptable 

Zebra Fish 

(Brachydanio rerio) 

(PCA); (Static) 

99.1 

LC50 > 96.7mg/L 

Slope = NA Practically 

non-toxic 47614990 Acceptable 

Rainbow Trout 

(Oncorhynchus mykiss) 

(PAM); (Static-renewal) 

100 

LC50 > 100.3 mg/L 

Slope = NA Practically 

non-toxic 47614991 Acceptable 

Rainbow Trout 

(Oncorhynchus mykiss) 

(753-A-OH); (Static) 

98.91 

LC50 > 9300 μg/L 

Slope = NA Moderately 

toxic 47614992 Acceptable 

Rainbow Trout 

(Oncorhynchus mykiss) 

(753-T-DO); (Static) 

99.84 

LC50 = 5004 μg/L 

(95% CI 4108-6472 μg/L) 

(soluble mean-measured) 

Slope = NA 

Moderately 

toxic 47614993 Supplemental

Table E.2. Freshwater Invertebrate Acute Toxicity to Penthiopyrad Metabolites 

Test Species/ 

Test Substance 

(Flow-through/Static)

Purity 

(%) 

48-hour EC50

(95% C.I.) 

(μg/L or mg/L, mean-measured)

Slope 

Toxicity 

Category MRID Study 

Classification

Waterflea 

(Daphnia magna) 

(DM-PCA); (Static)

99.9 EC50 > 99.42 mg/L 

Slope = NA Practically 

non-toxic 

47614997 Acceptable

Waterflea 

(Daphnia magna) 

(PCA); (Static)

99.1 EC50 > 91.75 mg/L 

Slope = NA Practically 

non-toxic 

47614998 Acceptable

Waterflea 

(Daphnia magna) 

(PAM); (Static)

100 EC50 > 100.5 mg/L 

Slope = NA Practically 

non-toxic 

47614999 Acceptable

Waterflea 

(Daphnia magna) 

(753-A-OH); (Static) 

98.91 EC50 > 8700 g/L 

Slope = NA 

Moderately 

toxic 47615001 Acceptable 

Waterflea 

(Daphnia magna) 

(753-T-DO); (Static) 

99.84 EC50 > 4478 g/L 

Slope = NA 

Moderately 

toxic 47615002 Supplemental
137

Table E.3. Acute Toxicity of Aquatic Non-Vascular Plants to Penthiopyrad Metabolites 

Test Species 

(Test Substance; Flowthrough/Static; Duration)

Purity 

(%) 

Endpoint 

(95% C.I.) 

(μg/L or mg/L, Measured)

Slope 

Effect MRID Study 

Classification

Green Alga 

(Desmodesmus subspicatus) 

(DM-PCA); (Static) 

99.9 

EC50 > 85.5 mg/L 

(mean-measured) 

Slope = NA 

No effect 47615009 Acceptable 

Green Algae 

(Pseudokirchneriella 

subcapitata) 

(PCA); (Static) 

99.1 

EC50 = 83 mg/L 

 (95% CI 78-88 mg/L) 

(mean-measured) 

Slope = 5.96  0.908 

(Cell density) 

& 5.97  0.909 (yield) 

Cell 

density & 

yield 

47615010 Acceptable 

Green Algae 

(Pseudokirchneriella 

subcapitata) 

(PAM); (Static) 

100 

EC50 > 100.4 mg/L 

(mean-measured) 

Slope = NA 

No effect 47615011 Supplemental

Green Algae 

(Pseudokirchneriella 

subcapitata) 

(753-A-OH); (Static) 

98.91 

EC50 > 8430 g/L 

(mean-measured) 

Slope = NA 

No effect 47615012 Acceptable 

Green Algae 

(Pseudokirchneriella 

subcapitata) 

(753-T-DO); (Static) 

99.8 

EC50 = 1800 g/L 

 (95% CI 1600-2000 g/L) 

NOAEC ≤ 459 g/L 

(initial measured) 

Slope = 4.64  0.421 

(Cell density) 

& 5.00  0.456 (yield) 

Cell 

density & 

yield 

47615013 Supplemental

Aquatic Organisms Toxicity Comparisons of Penthiopyrad TGAI and its Metabolites 

Acute aquatic toxicity data (fish, aquatic invertebrates, and algal studies) are available for the 

following five degradates of Penthiopyrad: DM-PCA, PCA, PAM, 753-A-OH, and 753-T-DO. 

A comparison using the molecular weights of the parent and respective degradates was used to 

determine if the degradate was of greater or less toxicity in relation to the parent penthiopyrad. 

To compare the parent and degradate acute toxicity the same species of fish (Rainbow trout) was 

used for all but one degradate (PCA) toxicity test. PCA however, used zebra fish instead, and 

therefore there is greater uncertainty associated with this comparison. The available acute fish 

toxicity data for DM-PCA, PCA, PAM, and 753-A-OH indicated that no effects were observed 

in the highest test concentration that was tested. Both the parent and all degradates utilized the 

same species, Daphnia magna, in examining effects to freshwater invertebrates. The available 

acute Daphnia data indicated that the degradates, DM-PCA and PCA, exhibited no effects (lethal 

or sublethal) at the highest test concentration tested. The other degradates; PAM, 753-A-OH, 

and 753-T-DO, exhibited sublethal effects at lower concentrations, and no immobility was 

observed in any test concentration. The available non-vascular aquatic plant toxicity data for the 

degradate utilized the same species (Pseudokirchneriella subcapitata) for all degradates except 

for DM-PCA, which utilized another green algal species, Desmodesmus subspicatus. The 

available algal toxicity data for PAM and 753-A-OH, indicated that no effects were observed in 
138

the highest concentration tested. The other degradates: DM-PCA; PCA, and 753-T-DO all 

exhibited toxicological effects that included inhibition of biomass (DM-PCA), and inhibition of 

cell density and yield (PCA and 753-T-DO). 

When the toxicity endpoints of the degradates were compared to the parent compound, it was 

determined that the degradates were considerably less toxic (1 to 3 orders of magnitude) to fish 

than the parent (Table 1). When the Daphnid degradate toxicity data was compared to the parent 

compound, the degradates, DM-PCA, PCA, and PAM, were all 3 orders of magnitude less toxic 

to aquatic invertebrates than the parent compound (Table 1). The other two degradates, 753-AOH and 753-T-DO, were of within the same magnitude of toxicity to aquatic invertebrates as the 

parent compound (Table 1); however, no treatment related effects were observed for the two 

transformation product degradates. When the algal degradate toxicity data was compared to the 

parent compound, the degradates, DM-PCA, PCA, and PAM, were all 3 orders of magnitude less 

toxic to algae than the parent compound (Table 1). The 753-A-OH degradate toxicity was within 

the same order of magnitude as the parent compound, however, no effects were observed. 

Whereas, the 753-T-DO degradate was found to be of similar toxicity to algae as the parent 

compound is (Table 1). However, the 753-T-DO degradate is a minor degradate, and 

transformation product to a less toxic major degradate, and therefore, is not expected to 

negatively impact non-target organisms. 

Table E.4. Comparison of Degradate Toxicity Compared to the Parent Compound* 

Test Material Test Species 

LC/EC50 

Toxicity 

Value 

(mg/L) 

Molecular 

weight 

(g/mol) 

Degradate toxicity 

(mg/L) 

expressed in terms of 

the parent compound1

Parent Penthiopyrad 

TGAI Rainbow Trout 0.290 359.42 -- 

DM-PCA Rainbow Trout >99.19 180.08 >197.97 

PCA Zebra Fish >96.7 194.11 >179.05 

PAM Rainbow Trout >100.3 193.13 >186.66 

753-A-OH Rainbow Trout >9.3 375.42 >8.90 

753-T-DO Rainbow Trout 4.6-5.0 391.41 4.59 

Parent Penthiopyrad 

TGAI Daphnia magna 2.53 359.42 -- 

DM-PCA D. magna >99.42 180.08 >198.43 

PCA D. magna >91.75 194.11 >169.89 

PAM D. magna >100.5 193.13 >187.03 

753-A-OH D. magna >8.7 375.42 >8.33 

753-T-DO D. magna >4.48 391.41 >4.11 

Parent Penthiopyrad 

TGAI 

Pseudokirchneriella subcapitata 

(green alga) 2.2 359.42 -- 

Parent Penthiopyrad 

TGAI P. subcapitata (green alga) 1.6 359.42 -- 

DM-PCA Desmodesmus subspicatus 

(green alga) >85.5 180.08 >170.65 

PCA P. subcapitata (green alga) 83.0 194.11 153.68 

PAM P. subcapitata (green alga) >100.4 193.13 >186.85 

753-A-OH P. subcapitata (green alga) >8.43 375.42 >8.07 
139

Test Material Test Species 

LC/EC50 

Toxicity 

Value 

(mg/L) 

Molecular 

weight 

(g/mol) 

Degradate toxicity 

(mg/L) 

expressed in terms of 

the parent compound1

753-T-DO P. subcapitata (green alga) 1.8 391.41 1.65 

1

 [(MW parent/MW degradate) * (toxicity endpoint degradate (mg/L))] 

* Bold values indicates potentially equal degradate toxicity when compared to the parent, penthiopyrad 

technical. 

Table E.5. Mammalian Acute Oral Toxicity to Penthiopyrad Metabolites 

Test Species 

(Test Substance) 

Purity 

(%) 

LD50 

(mg/kg-bw) 

Slope 

Toxicity 

Category MRID Study Classification

Sprague-Dawley rat 

(DM-PCA) 99.71 

>2,000 

Slope = NA Practically 

non-toxic 47614918 Acceptable

Sprague-Dawley rat 

(PCA) 99.92 

>2,000 

Slope = NA Practically 

non-toxic 47614924 Acceptable

Sprague-Dawley rat 

(PAM) 

99.97a 

100.0b

>300 < 2,000 

(cut-off LD50 = 500) 

Slope = NA 

Moderately to 

slightly toxic 

47614930a

& 

47614931b 

Acceptable

Sprague-Dawley rat 

(753-A-OH) 98.91 

>2,000 

Slope = NA Practically 

non-toxic 47614936 Acceptable

a

 MRID 47614930 - acute oral toxicity study using female Sprague-Dawley rats 

b

 MRID 47614931 - acute oral toxicity study using male Sprague-Dawley rats 

Table E.6. Toxicity to Earthworms 

Test Species / 

Test Substance

Purity 

(%) Endpoint Effect MRID Study Classification 

Earthworm 

Eisenia fetida 

DM-PCA

99.87 14-day LC50 >1000 mg/kg d.w. soil 

Slope = NA No effect 47615021 

Supplemental 

(non-guideline 

study) 

Earthworm 

Eisenia fetida 

PCA 

99.1 14-day LC50 >1000 mg/kg d.w. soil 

Slope = NA No effect 47615022 

Supplemental 

(non-guideline 

study) 

Earthworm 

Eisenia fetida 

PAM 

99.7 14-day LC50 >1000 mg/kg d.w. soil 

Slope = NA No effect 47615023 

Supplemental 

(non-guideline 

study) 

Earthworm 

Eisenia fetida 

DM-PCA 

99.87 NOAEC = 48 mg/kg d.w. soil 

LOAEC > 48 mg/kg d.w. soil No effect 47615025 

Supplemental 

(non-guideline 

study) 

Earthworm 

Eisenia fetida 

PCA 

99.1 NOAEC = 50 mg/kg d.w. soil 

LOAEC > 50 mg/kg d.w. soil No effects 47615026 

Supplemental 

(non-guideline 

study) 

Earthworm 

Eisenia fetida 

PAM 

99.7 NOAEC ≥ 50 mg a.i./kg d.w. soil 

LOAEC > 50 mg a.i./kg d.w. soil No effects 47615027 

Supplemental 

(non-guideline 

study) 
140

Appendix F. Comparison of Treoris Formulation and the Chlorothalonil 

Active Ingredient (TGAI) Toxicity. 

Table F.1. Comparison of Chlorothalonil Toxicity (Treoris formulated product and TGAI) 

Taxa 

(Study) Test Species Test Substance (Flow-through/Static) 

Endpoint 

(95% C.I.) 

(μg a.i./L, mean-measured)1

MRID

Freshwater 

Fish 

(Acute) 

Rainbow Trout Treoris* 96-hr LC50 = 25.4 μg a.i./L 

(95% CI 11.6-51.1 μg a.i./L) 47737323 

Rainbow Trout Chlorothalonil TGAI LC50 = 10.5 μg a.i./L 

Davies & 

White 

(1985)2

Freshwater 

Invertebrates 

(Acute) 

Daphnia magna Treoris* 48-hr EC50 = 45 μg a.i./L 

(95% CI 29.2-62.7 μg a.i./L) 47737324 

Daphnia magna Chlorothalonil TGAI 48-hr EC50 = 54 μg a.i./L 45710221 

NonVascular 

Aquatic 

plants 

(Acute) 

Freshwater green 

algae 

Pseudokirchneriella 

subcapitata

Treoris*

72-hr EC50 = 170 μg a.i./L 

(95% CI 130-220 μg a.i./L) 

NOAEC = 105 μg a.i./L 

EC05 = 65 μg a.i./L 

(Initial-measured) 

47737325 

Green Alga 

(Selenastrum 

capricornutum) 

Chlorothalonil TGAI 

EC50 = 6.8 μg a.i./L 

5-day EC50 = 190 μg a.i./L 

5-day NOAEC = 50 μg a.i./L 

Mezcua et 

al., 20023

42432801 

Honeybee 

(Acute 

Contact) 

Apis mellifera Treoris* 48-hr LD50 >22.8 μg 

chlorothalonil a.i./bee 47737326 

Apis mellifera Chlorothalonil TGAI 48-hr LD50 > 181 μg/bee 00077759 * Treoris is a co-formulaiton of penthiopyrad (8.91% a.i.) and chlorothalonil (22.3% a.i.); in the reported toxicity 

studies (rainbow trout, daphnia, green algae, and honeybee, the chemical analysis indicated that chlorothalonil was 

22.8% a.i. within the Treoris formulation. 

1 In terms of the chlorothalonil active ingredient for the Treoris formulation that is co-formulated with penthiopyrad; 

Treoris formulated product contains 22.3% chlorothalonil. 2

 Davies PE; White RWG. 1985. The Toxicology and Metabolism of Chlorothalonil in Fish. I. Lethal Levels for 

Salmo gairdneri, Galaxias maculates, G. truttaceus and G. auratus and the Fate of 14C-TCIN in S. gairdneri. Aquat 

Toxicol 7(1/2):93-105. 3

 Mezcua, M., Hernando, M.D., Piedra, L., Aguera, A., Fernandez-Alba, A.R. 2002. Chromatogrophy-Mass 

Spectometry and Toxicity Evaluation of Selected Contaminants in Seawater. Chromatographia 56(3/4):199-205. 
141

Appendix G. Provisional Tier I Cranberry Model Equations. 

The Provisional Cranberry Model is a refinement of the Tier I Rice Model v1.0 

(Equations 1 and 2), which is a simple equilibrium partitioning equation that calculates a single, 

screening-level concentration in rice paddy water and released tailwater based on a compound’s 

application rate and soil mobility. 

Equations 1-2: Tier I Rice Model v1.0 (USEPA, 2007b).

  w sed sed b d

ai

w d d K

m C

 3

2

0 10

10 '

    (1) 

and, if appropriate: 

Kd KOC  0.01 (2) 

where, 

 Cw0 = initial water concentration [μg/L] 

mai' = mass applied per unit area [kg/ha] 

Kd = water-sediment partitioning coefficient [L/kg] 

KOC = organic carbon partitioning coefficient [L/kg] 

dw = water column depth = 0.10 m 

dsed = sediment depth = 0.01 m 

θsed = porosity of sediment = 0.509 

ρb = bulk density of sediment = 1300 kg/m3

 First, the Tier I Rice Model was provisionally modified (Equation 3) to include as inputs 

degradation rate constants in order to estimate single, screening-level concentrations in paddy 

water at a given time after application. 

Equation 3: Provisional Modified Rice Model (Jones, 2006).

d

kt

ai

w K

m e C

0.00105 0.00013

'

 



 (3) 

where, 

 Cw = water concentration [μg/L] 

 t = interval since last application [d] 

 k = upper 90th percentile of aerobic aquatic metabolism study rate constants [1/d] 

 Then, the provisional Modified Rice Model water column depth was lengthened to a 

depth that is used to flood cranberry bogs (i.e., 12 inches; Cape Cod Cranberry Growers 

Association, 2001). 
142

i.e., 

 dw = water column depth = 0.305 m 

 In order to model degradation prior to the flood at harvest, the application rates for n 

number of pre-harvest applications were independently degraded over the interim until flooding 

and then summed (Equation 4). 

Equation 4: Degradation in a Dry Bog. 

   

n k t

ai ai n n m m e

1

2 ' ' (4) 

 where, 

 mai' = mass per unit area at flood [kg/ha] 

 mai'n = mass applied per unit area on the nth application [kg/ha] 

 k2 = upper 90th percentile of aerobic soil metabolism study rate constants [1/d] 

 tn = interval from the nth application to harvest [d] 

 n = number of pre-harvest applications 

 These four equations and parameter sets constitute the provisional Tier I Cranberry 

Model (Equations 1-4). 
143

Equations 2, 4, and 5: Provisional Tier I Cranberry Model.

   

n k t

ai ai n n m m e

1

2 ' ' (4) 

 where, 

 mai' = mass per unit area at flood [kg/ha] 

 mai'n = mass applied per unit area on the nth application [kg/ha] 

 k2 = upper 90th percentile of aerobic soil metabolism study rate constants [1/d] 

 tn = interval from the nth application to harvest [d] 

 n = number of pre-harvest applications 

followed by: 

  w sed sed b d

kt

ai

w d d K

m e C

 3

2

10

10 '





   (5) 

and, if appropriate: 

Kd KOC  0.01 (2) 

 where, 

 Cw = water concentration [μg/L] 

 t = interval since flood [d] 

 k = upper 90th percentile of aerobic aquatic metabolism study rate constants [1/d] 

 Kd = water-sediment partitioning coefficient [L/kg] 

 KOC = organic carbon partitioning coefficient [L/kg] 

 dw = water column depth = 0.305 m 

 dsed = sediment depth = 0.01 m 

 θsed = porosity of sediment = 0.509 

 ρb = bulk density of sediment = 1300 kg/m3
144

Appendix H. Submitted Ecological Effects Studies for Penthiopyrad and Analysis of Data Table H.1. Submitted Ecological Effects Studies for Penthiopyrad and whether Additional Data are Neces

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification

Sufficient Risk Assessme

850.1010 Daphnid Acute Toxicity 

47614996 Although no precipitate was observed in the study, the 

three highest test concentrations were above the water solubility limit of the test item (1375g a.i./L).

Acceptable 

Ye

47615226 Penthiopyrad Suspension Concentrate (SC) Formulation 

(DPX-LEM17 20SC) was the test substance; there were no 

issues with the study. 

Acceptable 

47615227 Penthiopyrad Suspension Concentrate (SC) Formulation 

(DPX-LEM17 20SC) was the test substance. The lower bound confidence interval for the EC50 was below the lowest concentration tested; in addition 100% of treated daphnids displayed lethargy (the sublethal effect observed) in all test concentrations except the highest level where there was complete mortality. It was concluded that the selection of the test concentrations were not appropriate and could not accurately quantify the risk of the penthiopyrad SC formulation to Daphnia. The study cannot 

be upgraded. 

Supplemental

47615228 Penthiopyrad Suspension Concentrate (SC) Formulation 

(DPX-LEM17 20SC) was the test substance. Test organisms were fed during the study, and that is considered a guideline deviation. In addition, the sublethal effect observed was lethargy, which was 100% in the three highest treatment levels, and 65% in the lowest treatment level Therefore, it was concluded that the selection of the test concentrations were not appropriate and could not accurately quantify the risk of the penthiopyrad SC formulation to Daphnia. The study cannot be upgraded. 

Supplemental
145

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification

Sufficient Risk Assessme

47615229 Penthiopyrad Suspension Concentrate (SC) Formulation 

(DPX-LEM17 20SC) was the test substance. Test organisms were fed during the study, and were also older than recommended in the guideline; both are considered to 

be guideline deviations. Neonates are considered a more sensitive life stage for Daphnia magna than 14/28 day adults, and therefore, the relevance of the study is limited. The study cannot be upgraded. 

Supplemental

47615336 Penthiopyrad Emulsifiable Concentrate (EC) Formulation 

(DPX-LEM17 20EC) was the test substance; there were no 

issues with the study. 

Acceptable 

47737324 Multi-Active Ingredient (Chlorothalonil/ Penthiopyrad; 

250g/L:100g/L) Suspension Concentrate (SC) Formulation (DPX-QFA61 SC) was the test substance; there were no issues with the study. 

Acceptable 

47615234 Penthiopyrad Suspension Concentrate (SC) Formulation 

(DPX-LEM17 20SC) was the test substance. Control mortality was 20% in this study, exceeding the 10% maximum acceptable control mortality. There also appeared to be issues with solubility at the highest test level, as the test solution appeared cloudy white with a surface film, without report of centrifugation prior to 

analysis. 

Invalid 

47615235 Penthiopyrad Suspension Concentrate (SC) Formulation 

(DPX-LEM17 20SC) was the test substance. A precipitate was observed in the two highest test concentrations, and the test material was not centrifuged prior to being measured. Failure to centrifuge is an important flaw in the study design, and it raises the concern of potentially underestimating the toxicity of the penthiopyrad SC formulation. 

Invalid 
146

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification

Sufficient Risk Assessme

850.1025 Oyster Acute Toxicity Test 

47615033 None Acceptable 

No 

47615233 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance. Whenever there is a precipitate observed or if any treatment 

concentration is at or near the solubility limit, centrifugation is needed to ensure that measured concentrations are of the soluble concentration of the active ingredient and not total (solid + soluble). However in this study samples were not centrifuged, which raises a concern that samples do not represent only soluble penthiopyrad concentrations. Due to the high Kow (log =4.6) of 

penthiopyrad there is concern about the sorption of the chemical to any organic matter present in the test water. The failure to centrifuge the concentrations prior to measurement is an important flaw in the study design, and it impacts the reliability of this study. 

Invalid 

850.1035 Mysid Acute Toxicity 

47615032 None Acceptable 

No 

47615231 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance. At test initiation the solutions of the highest two test levels (2500 and 5000 μg a.i./L) were cloudy white, with a precipitate on the surface, and all other test solutions appeared clear and colourless. At test termination however, all solutions appeared the same as before with the addition of a white 

precipitate on the surface of the 1300, 2500, and 5000 μg a.i./L test solutions. Test samples were not centrifuged, which raises a concern that samples do not represent only soluble penthiopyrad concentrations. Due to the high Kow

(log =4.6) of penthiopyrad there is concern about the sorption of the chemical to any organic matter present in the test water. The failure to centrifuge the concentrations prior to measurement is an important flaw in the study design, and it impacts the reliability of this study. 

Invalid 
147

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification

Sufficient Risk Assessme

850.1075 Fish Acute Toxicity 

47614984 

Penthiopyrad was not stable under static conditions in the 38 to 300 μg a.i./L nominal treatment levels. The measured concentrations at 96 hrs in these treatments were 77.0% to 79.9%, of measured concentrations at test initiation. The effect of the observed instability at the lower concentrations is not considered to have impact on the study outcome. 

Acceptable 

Yes; howe

for 

estuarine/

fish

47614986 

No measurements or details of the renewal of the test substance in the diluter stock solution were reported. Without information regarding the dilutor stock, it is not possible to verify the stability of penthiopyrad concentrations over time. The study is upgradeable with 

documentation showing additional penthiopyrad measurements during the study that verify stable penthiopyrad concentrations or measurements of the test substance in the diluter stock solution that verifies stable penthiopyrad concentrations or details of renewal of the test substance in the diluter stock solutions. This study is upgradeable. 

Supplemental

47614987 

The study cannot be upgraded, as the test material was not centrifuged prior to being measured. This raises a concern that samples do not represent only the soluble penthiopyrad concentrations. 

Invalid 

47614988 

Although there was some uncertainty associated with the lack of measurement of test concentrations at test material renewal, there were three measurements of the test concentrations and so there is some confidence in the mean-measured concentrations. In addition, all the measured concentrations were well within 20% of meanmeasured concentrations for all but the second lowest test 

concentration. 

Acceptable 
148

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification

Sufficient Risk Assessme

47615034 

Although there was some uncertainty associated with the lack of measurement of test concentrations at test material renewal, there were three measurements of the test concentrations and so there is some confidence in the mean-measured concentrations. In addition, all the measured concentrations were within 20% of nominal concentrations for all but the highest test concentration. 

Acceptable 

47615225 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance; there were no 

issues with the study. 

Acceptable 

47615232 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance. Test samples were not centrifuged; they instead were mixed with a topdown mixer, which raises a concern that samples do not represent only soluble penthiopyrad concentrations. This study does not satisfy data requirement and it cannot be upgraded. 

Supplemental

47615335 

Penthiopyrad Emulsifiable Concentrate (EC) Formulation (DPX-LEM17 20EC) was the test substance; there were no 

issues with the study. 

Acceptable 

47737323 

Multi-Active Ingredient (Chlorothalonil/ Penthiopyrad; 250g/L:100g/L) Suspension Concentrate (SC) Formulation (DPX-QFA61 SC) was the test substance. Fish were not exposed to stable formulation concentrations throughout the exposure duration of the test as both penthiopyrad and chlorothalonil were not stable under the static test conditions. Chlorothalonil concentrations at 96 hours ranged from 23 to 76% of initial test levels and penthiopyrad concentrations ranged from 23 to 94% of initial test levels. This study may be used to satisfy data requirement. 

Supplemental
149

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification

Sufficient Risk Assessme

850.1300 Life-Cycle 

Toxicity Daphnid 

47615003 None Acceptable 

Ye

47615236 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance; there were no 

issues with the study. 

Acceptable 

850.1400 Fish Early LifeStage Toxicity 47614994 None Acceptable Ye850.2100 Avian Acute Oral Toxicity 

47614977 None Acceptable 

No 

47614978 

Significant regurgitation of the test material (≥30% of birds at ≥156 mg a.i./kg bw levels), as a result an LD50 could not 

be calculated. However, the observed regurgitation was determined to be a toxic effect related to chemical exposure, therefore, an effect dose (ED50) was calculated 

using regurgitation as the observed effect for characterization purposes only. This study does not satisfy the data requirement; and the study cannot be upgraded. 

Supplemental

47615249 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance; there were no 

issues with the study. 

Acceptable 

850.2200 

Avian Sub-acute Dietary Toxicity 

47614979 None Acceptable 

Yes

47614981 None Acceptable 

850.2300 Avian Reproduction 47614982 

The control mortality in this study (12.5%; 3 females and 1 male out of 16 pairs) exceeded the limit for an acceptable study. The effects that were seen in the necropsies of the dead control birds raise concerns relating to potential impacts on reproduction of the other control birds, resulting in an overall decreased eggs laid mean for the control birds. As a result, risk may potentially be underestimated. This study does not satisfy data requirement; it will not be used quantitatively in the risk assessment, and the study cannot be upgraded. 

Supplemental No 

47614983 None Acceptable 
150

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification

Sufficient Risk Assessme

850.3020 Honeybee Acute Contact Toxicity 

47615017 

A negative control was not tested concurrently with the solvent control during this study. This study does not satisfy data requirement and it cannot be upgraded. 

Supplemental

No 

47615237 None Acceptable 47615337 None Acceptable 47737326 None Acceptable 

850.4100 

Terrestrial Plant Toxicity (Seedling Emergence) 47615037 

It was noted that definitive NOAECs were not obtained for ryegrass, sugarbeet, wheat, and tomato, as these species exhibited statistically significant reductions at the limit concentration relative to the negative control (and/or pooled or formulation controls), therefore, Tier II toxicity studies will be required for these species. 

Acceptable No 

850.4150 

Terrestrial Plant Toxicity (Vegetative Vigor) 47615038 

It was noted that definitive NOAEC’s were not obtained for wheat, and soybean, as these species exhibited statistically significant reductions at the limit concentration relative to the negative control (and/or pooled or formulation controls), therefore, Tier II toxicity studies will be required 

for these species. 

Acceptable No 

850.4400 

Aquatic Plant Toxicity Test using Lemna

47615015 None Acceptable Ye

850.5400 Algal Toxicity Test 

47615004 The test was only conducted for 72 hours, and OCSPP 

(form. OPPTS) guidelines suggest a testing period of 96 hours for algae toxicity studies. This study does not satisfy data requirement and it cannot be upgraded. 

Supplemental

47615005 None Acceptable Ye47615006 None Acceptable 47615007 None Acceptable 47615008 None Acceptable 
151

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification

Sufficient Risk Assessme

47615230 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance. The test was only conducted for 72 hours, and OCSPP (form. OPPTS) guidelines suggest a testing period of 96 hours for algae toxicity studies. This study does not satisfy data requirement and it cannot be upgraded. 

Supplemental

47737325 

Multi-Active Ingredient (Chlorothalonil/ Penthiopyrad; 250g/L:100g/L) Suspension Concentrate (SC) Formulation (DPX-QFA61 SC) was the test substance. The test was only conducted for 72 hours, and OCSPP (form. OPPTS) guidelines suggest a testing period of 96 hours for algae toxicity studies. In addition, algae were not exposed to stable formulation concentrations throughout the exposure duration of the test, although penthiopyrad was considered to be relatively stable, chlorothalonil and the total formulation were not stable under the static test conditions. This study does not satisfy data requirement and the study cannot be upgraded. 

Supplemental

NA OECD 213 

None; Honeybee Acute Oral Toxicity 

47615016 Non-guideline study; a negative control was not tested concurrently with the solvent control during this study. Supplemental

Can on

consid

supplem

informat

use by 

Agen

47615237 

Non-guideline: The results for the acute oral study can only be considered supplemental information for use by the Agency. 

Supplemental

47615337 

Non-guideline: The results for the acute oral study can only be considered supplemental information for use by the Agency. 

Supplemental

47737326 

Non-guideline: The results for the acute oral study can only be considered supplemental information for use by the Agency. 

Supplemental
152

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification

Sufficient Risk Assessme

NA OECD 218 

Prolonged Sediment Toxicity with Chironomus riparius

47615014 

Non-guideline study; According to OECD 218, sediment should be sampled from every test concentration analyzed for concentrations of the test chemical prior to adding test organisms. This was not provided in the submitted study report. The analytical measurements were made only from the lowest and the highest test concentrations, and not all six test concentrations. This study may be used to fulfil the data requirement. 

Supplemental Ye

NA 

None; Beneficial Insects - Effects on the Parasitic Wasp 

47615018 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance. Nonguideline study; Testing for effects on arthropods species other than bees was carried out using the formulated product Penthiopyrad 20 SC rather than the active substance. In addition, there are no OCSPP guidelines for the parasitic wasp, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental

Yes; con

supplem

informat

use by 

Agen

47615239 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance. Nonguideline study; there are no OCSPP guidelines for a rateresponse laboratory test for the parasitic wasp, and therefore the results for the study can only be considered 

supplemental information for use by the Agency. 

Supplemental

47615338 

Penthiopyrad Emulsifiable Concentrate (EC) Formulation (DPX-LEM17 20EC) was the test substance. Nonguideline study; there are no OCSPP guidelines for a rateresponse laboratory test for the parasitic wasp, and therefore the results for the study can only be considered 

supplemental information for use by the Agency. 

Supplemental
153

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification

Sufficient Risk Assessme

NA 

None; Beneficial Insects - Effects on the Predatory Mite 

47615019 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance. Nonguideline study; Testing for effects on arthropods species other than bees was carried out using the formulated product Penthiopyrad 20 SC rather than the active substance. In addition, there are no OCSPP guidelines for the predatory mite, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental

Yes; con

supplem

informat

use by 

Agen

47615238 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance. Nonguideline study; there are no OCSPP guidelines for a rate response laboratory test for the predatory mite, and therefore the results for the study can only be considered 

supplemental information for use by the Agency. 

Supplemental

47615339 

Penthiopyrad Emulsifiable Concentrate (EC) Formulation (DPX-LEM17 20EC) was the test substance. Nonguideline study; there are no OCSPP guidelines for a rateresponse laboratory test for the predatory mite, and therefore the results for the study can only be considered 

supplemental information for use by the Agency. 

Supplemental

47615240 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance. Nonguideline study; there are no OCSPP guidelines for an extended rate-response laboratory test for the predatory mite, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental
154

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification

Sufficient Risk Assessme

47615340 

Penthiopyrad Emulsifiable Concentrate (EC) Formulation (DPX-LEM17 20EC) was the test substance. Nonguideline study; there are no OCSPP guidelines for an extended rate-response laboratory test for the predatory mite, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental

Yes; con

supplem

informat

use by 

Agen

NA 

None; Beneficial Insects - Effects on the Predatory Bug 

47615241 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance. Nonguideline study; there are no OCSPP guidelines for an extended rate-response laboratory test for the predatory bug, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental

Yes; con

supplem

informat

use by 

Agen

47615341 

Penthiopyrad Emulsifiable Concentrate (EC) Formulation (DPX-LEM17 20EC) was the test substance. Nonguideline study; there are no OCSPP guidelines for an extended rate-response laboratory test for the predatory bug, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental

NA 

None; Beneficial Insects - Effects on the Green Lacewing 

47615242 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance. Nonguideline study; there are no OCSPP guidelines for an extended rate-response laboratory test for the green lacewing, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental

Yes; con

supplem

informat

use by 

Agen
155

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification

Sufficient Risk Assessme

47615342 

Penthiopyrad Emulsifiable Concentrate (EC) Formulation (DPX-LEM17 20EC) was the test substance. Nonguideline study; there are no OCSPP guidelines for an extended rate-response laboratory test for the green lacewing, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental

Yes; con

supplem

informat

use by 

Agen

NA OECD 207 

None; Acute Toxicity to Earthworms 

47615020 

Non-guideline study; OECD guideline 207 (1984) states that the artificial soil test should be carried out under continuous light but in this study a photoperiod of 16 h light: 8 h dark is adopted. This deviation could potentially impact the exposure of earthworms to the test substance. In addition, there are no OCSPP guidelines for an acute earthworm toxicity test, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental

Yes; con

supplem

informat

use by 

Agen

47615244 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance. Nonguideline study; there are no OCSPP guidelines for an acute earthworm toxicity test, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental

NA 

None; Subchronic Earthworm Toxicity 

47615024 

Non-guideline study; the OCSPP guideline (850.6200) for a subchronic earthworm toxicity test was not used, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental

Yes; con

supplem

informat

use by 

Agen

47615245 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance. Nonguideline study; the OCSPP guideline (850.6200) for a subchronic earthworm toxicity test was not used, and therefore the results for the study can only be considered 

supplemental information for use by the Agency. 

Supplemental
156

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification

Sufficient Risk Assessme

NA 

None; Effects on the Activity of Soil Microflora (Nitrogen Transformation) 

47515028 

Non-guideline study; there are no OCSPP guidelines for assessing the impacts on soil microbial activity, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental

Yes; con

supplem

informat

use by 

Agen

47615246 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance. Nonguideline study; there are no OCSPP guidelines for assessing the impacts on soil microbial activity, and therefore the results for the study can only be considered 

supplemental information for use by the Agency. 

Supplemental

47615343 

Penthiopyrad Emulsifiable Concentrate (EC) Formulation (DPX-LEM17 20EC) was the test substance. Nonguideline study; there are no OCSPP guidelines for assessing the impacts on soil microbial activity, and therefore the results for the study can only be considered 

supplemental information for use by the Agency. 

Supplemental

NA 

None; Effects on the Breakdown of Organic Matter in Litter Bags 

47615035 & 47615041 

Non-guideline study; there are no OCSPP guidelines for assessing the effects on the breakdown of organic matter in litter bags in the field, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental

Yes; con

supplem

informat

use by 

Agen

NA 

None; Effects on Microorganisms with Sludge Respiration Inhibition Test (Biological Methods for Sewage Treatment) 

47615039 

Non-guideline study; there are no OCSPP guidelines for assessing the effects on biological methods for sewage treatment, and therefore the results for the study can only 

be considered supplemental information for use by the Agency. 

Supplemental

Yes; con

supplem

informat

use by 

Agen
157

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification

Sufficient Risk Assessme

NA 

None; Field Study to Evaluate Effects on Predatory Mites 

47615243 

Penthiopyrad Suspension Concentrate (SC) Formulation (DPX-LEM17 20SC) was the test substance. Nonguideline study; there are no OCSPP guidelines for field studies on predatory mites, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental

Yes; con

supplem

informat

use by 

Agen

Table H.2. Submitted Ecological Effects Studies for Degradates of Penthiopyrad and whether Additional 

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification 

SufficRisk Assess

850.1010 Daphnid Acute Toxicity

47614997 

DM-PCA was the test substance. Although, the particulate matter, dissolved and total organic carbon (DOC/TOC) content of dilution water were not reported, the DM-PCA metabolite of penthiopyrad is highly soluble (8240 mg/L). 

Therefore, the absence of this information (particulate matter and DOC/TOC) does not impact the toxicity results seen for the metabolite, and it was determined that the validity of the study was not impacted by these deficiencies.

Acceptable 

Y

47614998 

PCA was the test substance. Although, the particulate matter, dissolved and total organic carbon (DOC/TOC) content of dilution water were not reported, the PCA metabolite of penthiopyrad is highly soluble (1.2 g/L). Therefore, the absence of this information (particulate matter and DOC/TOC) does not impact the toxicity results seen for the metabolite, and it was determined that the validity of the study was not impacted by these deficiencies.

Acceptable 
158

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification 

SufficRisk Assess

47614999 

PAM was the test substance. Although, the particulate matter, dissolved and total organic carbon (DOC/TOC) content of dilution water were not reported, the PAM metabolite of penthiopyrad is highly soluble (>100 mg/L). Therefore, the absence of this information (particulate matter and DOC/TOC) does not impact the toxicity results seen for the metabolite, and it was determined that the validity of the study was not impacted by these deficiencies.

Acceptable 

47615001 753-A-OH was the test substance. There were no issues. Acceptable 47615002 

753-T-DO was the test substance. There is uncertainty in the representation of the soluble exposure concentration at the highest treatment level since there was a rank order reversal in the mean-measured soluble concentrations of 753-T-DO between the highest and second highest treatment levels, as compared to the nominal and noncentrifuged mean-measured concentrations. This study does not satisfy data requirement and the study cannot be upgraded 

Supplemental Y

850.1075 Fish Acute Toxicity 47614989 

DM-PCA was the test substance. The particulate matter and dissolved or total organic carbon (DOC/TOC) content of the dilution water were not reported and these constituents when above guideline standards can result in the underestimation of toxicity as compared to standard test conditions. However, the DM-PCA metabolite is highly 

soluble (8240 mg/L), and the absence of the information regarding the concentration of particulate matter and DOC/TOC would not impact the toxicity results seen for the metabolite. 

Acceptable Y
159

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification 

SufficRisk Assess

47614990 

PCA was the test substance. The particulate matter and dissolved or total organic carbon (DOC/TOC) content of the dilution water were not reported and these constituents when above guideline standards can result in the underestimation of toxicity as compared to standard test conditions. However, the PCA metabolite is highly soluble (1.2 g/L), and the absence of the information regarding the concentration of particulate matter and DOC/TOC would not impact the toxicity results seen for the metabolite. 

Acceptable 

47614991 PAM was the test substance. There were no issues. Acceptable 47614992 753-A-OH was the test substance. There were no issues. Acceptable 47614993 

753-T-DO was the test substance. There is uncertainty in the representation of the exposure concentration at the highest treatment level, as a precipitate was present at test initiation and for the duration of the test, and the 753-T-DO soluble concentration was not stable over the exposure period in the highest treatment. Although this study is supplemental, it can be used to satisfy the data requirement. 

Supplemental Y

850.5400 Algal Toxicity Test 47615009 

DM-PCA was the test substance. The source and type of water used to prepare the test medium was not reported. This is considered a deviation from the OECD guideline 201 and OCSPP (form. OPPTS) guideline 850.5400. In addition, the pH ranged from 7.05 to 9.86, which is well in excess of the 1.5 units allowed under OECD Guideline 201. Australia’s (APVMA) experience finds that this often found as it is caused by the CO2 consumption of the algae due to 

their rapid growth or their high densities. However, these deviations are not expected to impact the validity of this study or the reliability of the results. 

Acceptable Y
160

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification 

SufficRisk Assess

47615010 

PCA was the test substance. It is a deviation from the OECD guideline to use purified water instead of deionized or distilled water. In addition, the pH ranged from 6.1 to 8.4 at test initiation; 6.5 to 9.6 at test termination, which is well in excess of the 1.5 units allowed under OECD Guideline 201. Australia’s (APVMA) experience finds that this often found as it is caused by the CO2 consumption of 

the algae due to their rapid growth or their high densities. However, these deviations are not expected to impact the validity of this study or the reliability of the results. 

Acceptable 

47615011 

PAM was the test substance. The test was only conducted for 72 hours, and OCSPP (form. OPPTS) guidelines suggest a testing period of 96 hours for algae toxicity studies. This study does not satisfy data requirement and it cannot be upgraded. 

Supplemental 

47615012 

753-A-OH was the test substance. It is a deviation from the OECD guideline to use purified water instead of deionized or distilled water. In addition, the OECD 201 guideline states that test item results should be compared to solvent controls. However, these deviations are not expected to impact the validity of this study or the reliability of the results, as the results for the control organisms were within the expected range. 

Acceptable Y
161

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification 

SufficRisk Assess

47615013 

753-T-DO was the test substance. Significant differences between the solvent control and negative control suggest a possible inhibitory effect of the solvent. However, since test item results have been compare to negative controls the endpoints were considered conservative. Given the low recovery of the test item by the end of the study (below the LOQ, 300 μg/L), OECD 201 indicates that results based on initial measured concentrations may not be appropriate. In addition, there is evidence of decreasing growth inhibition over time as concentrations decline and therefore the use of initial measured values in CRD, PMRA, or APVMA risk assessments would not be considered appropriate. However, based on EPA guidance the initial measured concentrations should be used in cases of significant loss of the chemical, in addition, EPA guidance compares the treatment group(s) to the negative control. Due to the uncertainty in the representation of the soluble exposure concentration that the test organisms were exposed to for the duration of the test, the reliability of the results was impacted. This study does not satisfy data requirement and it cannot be upgraded. 

Supplemental Y

NA OECD 207 

None; Acute Toxicity to Earthworms 

47615021 

DM-PCA was the test substance. Non-guideline study; OECD guideline 207 (1984) states that the artificial soil test should be carried out under continuous light but in this study a photoperiod of 16 h light: 8 h dark is adopted. This deviation could potentially impact the exposure of earthworms to the test substance. In addition, there are no OCSPP guidelines for an acute earthworm toxicity test, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental Y

cons

supple

infor

for us

Ag

47615022 

PCA was the test substance. Non-guideline study; there are no OCSPP guidelines for an acute earthworm toxicity test, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental 
162

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification 

SufficRisk Assess

47615023 

PAM was the test substance. Non-guideline study; there are no OCSPP guidelines for an acute earthworm toxicity test, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental 

NA 

Subchronic Earthworm Toxicity 

47615025 

DM-PCA was the test substance. Non-guideline study; the OCSPP guideline (850.6200) for a subchronic earthworm 

toxicity test was not used, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental 

Y

cons

supple

infor

for us

Ag

47615026 

PCA was the test substance. Non-guideline study; the OCSPP guideline (850.6200) for a subchronic earthworm toxicity test was not used, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental 

47615027 

PAM was the test substance. Non-guideline study; the OCSPP guideline (850.6200) for a subchronic earthworm toxicity test was not used, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental 

NA 

Effects on the Activity of Soil Microflora (Nitrogen Transformation) 

47515029 

DM-PCA was the test substance. Non-guideline study; there are no OCSPP guidelines for assessing the impacts on soil microbial activity, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental Y

cons

supple

infor

for us

Ag

47615030 

PCA was the test substance. Non-guideline study; there are no OCSPP guidelines for assessing the impacts on soil microbial activity, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental
163

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification 

SufficRisk Assess

47615031 

PAM was the test substance. Non-guideline study; there are no OCSPP guidelines for assessing the impacts on soil microbial activity, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental

NA 

None; Effects on the Breakdown of Organic Matter in Litter Bags 

47615036 

DM-PCA was the test substance. Non-guideline study; there are no OCSPP guidelines for assessing the effects on the breakdown of organic matter in litter bags in the field, and therefore the results for the study can only be considered supplemental information for use by the Agency. 

Supplemental 

Y

cons

supple

infor

for us

Ag
164

Appendix I. Submitted Environmental Fate Studies for Penthiopyrad. Table I.1. Submitted Environmental Fate Studies for Penthiopyrad and Whether Additional Data are Nec

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification 

Sufficient foRisk Assessment? 

835.2120 Hydrolysis 47614837 Test concentrations may have exceeded the aqueous 

solubility of the test compound. 

Acceptable Yes 

835.2240 Aqueous 

photolysis 

47614839 None. Acceptable Yes 

835.2410 Soil photolysis 47614965 Mixed radiolabels were used in the test systems. Also, 

the extraction procedure was not considered exhaustive (and up to 12.3-24.6%AR was unextracted). 

Supplemental Yes 

835.4100 Aerobic soil 

metabolism 

47614959 Studies of Soils I and IV were terminated before the 

first DT50 of the test compound had passed. Also, the extraction procedure was not considered exhaustive (and up to 39.9%AR was unextracted). 

Supplemental Yes 

47614961 Only one soil was studied. The extraction procedure 

was not considered exhaustive (and up to 36.5%AR was unextracted). 

Supplemental 

47614963 Only one soil was studied. The extraction procedure 

was not considered exhaustive (and up to 26.8%AR was unextracted). Also, the taxonomy of the test soil, which may have been a volcanic soil, was not reported. 

Supplemental 

835.4200 Anaerobic soil 

metabolism 

47614964 The extraction procedure was not considered exhaustive 

(and up to 33.2%AR was unextracted).

Supplemental Yes 

835.4300 Aerobic aquatic 

metabolism 

47614975 The studies were terminated before the first DT50 of the 

test compound had passed. 

Supplemental Yes 

835.4400 Anaerobic aquatic 

metabolism 

47614976 One test system was studied rather than two. Supplemental Yes 
165

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification 

Sufficient foRisk Assessment? 

835.1230 Batch equilibrium 47614967 It is not clear which reported values are raw versus 

calculated values. And study calculations, such as the mass of test item sorbed to soil at equilibrium, were not described and demonstrated. Therefore, calculated sorption parameters could not be confirmed using the raw data. Also, at least one soil should have had an organic matter content less than 1%. 

Supplemental Yes 

835.6100 Terrestrial field 

dissipation 

47615162 None. Acceptable Yes 

47615163 None. Acceptable 47615164 None. Acceptable 47615165 Some intervals were not analyzed to a depth of no 

residue detection. 

Acceptable 

47615166 Some intervals were not analyzed to a depth of no 

residue detection. Also, full soil taxonomic 

classifications were not provided. 

Acceptable 

47615167 Some intervals were not analyzed to a depth of no 

residue detection. Also, full soil taxonomic 

classifications were not provided. 

Acceptable 

47615172 Some intervals were not analyzed to a depth of no 

residue detection. 

Acceptable 

47615173 Some intervals were not analyzed to a depth of no 

residue detection. 

Acceptable 

Storage stability 47615161 None. Acceptable Yes Analytical method in soil 

47615105/ 47614867 

None. Acceptable Yes 

Analytical method in water 

47614868/ 47614869 

The ECM is acceptable for surface water and ground water with an LOQ below toxicological LOCs for the residues of concern (with the exception that 753-F-DO is not an analyte). The ECM is unacceptable for drinking water due to lack of independent validation. 

Acceptable Yes 

Analytical method in air 

47614870 Air ECM lacks an independent validation report. Unacceptable 

& upgradeable 

Yes 
166

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification 

Sufficient foRisk Assessment? 

165-4 (850.1730) 

Fish bioaccumulation 

47614995 TOC concentrations were high in the test systems and 

untreated water. 

Supplemental Yes 

835.3110 Ready 

biodegradability 

47614974 None. Acceptable Yes 

Table I.2. Submitted Environmental Fate Studies for Degradates of Penthiopyrad and Whether Additiona

OCSPP Guideline 

Data Requirement 

Submitted Studies (MRID) 

Study Issues Review 

Classification 

SufficRisk Assess

835.4100 Aerobic soil 

metabolism 

47614966 DM-PCA was the test substance. Acceptable Yes 

835.1230 835.1240 

Batch equilibrium 47614966 DM-PCA was the test substance. Acceptable 

47614968 PCA was the test substance. An HPLC method was used. And 

the log Koc for PCA fell outside of the range of the reference items used in this study, as did the retention time of PCA. 

Unacceptable 

47614969 PCA was the test substance. It is questionable whether 

equilibrium was reached after 4 hours and whether it is a valid approach to use data from a soil that is has been discounted due to anomalous results, to establish the equilibrium time. 

Unacceptable 

47614971 PAM was the test substance. At least one soil should have had 

an organic matter content less than 1%. 

Acceptable 

47614972 753-A-OH was the test substance. At least one soil should 

have had an organic matter content less than 1%. 

Acceptable 

47614973 753-T-DO was the test substance. At least one soil should have 

had an organic matter content less than 1%. 

Acceptable