3+<E0 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON D.C., 20460 

OFFICE OF 

PREVENTION, PESTICIDES AND 

TOXIC SUBSTANCES 

PC Code: 000692 

DP Barcodes: 332763,332767 

Date: April 12,2007 

MEMORANDUM 

SUBJECT: Environmental Fate and Ecological Risk Assessment in Support of the Section 3 

Registration of the New Chemical Pyrasulfotole (Bayer 309). 

TO: Tracy White, Chemical Review Manager 

Joanne Miller, Risk Manager 

Registration Division (7505P) 

y- ,2-67 

FROM: Melissa A. Panger, Ph.D., Biologist ( L' ' * 

Marietta Echeverria, Environmental &- 4 //2/0 . 7. 

Environmental Risk Branch IV . \ 

Megan Thynge, Environmental Protection Specialist 1 C t \ 

Environmental Information and Support Branch I 

' I 

Environmental Fate and Effects Division (7507P) 

REVIE WED !?-- , d cT tT -, BY: Thomas 

R. David 

M. 

Jones, 

Steeger, 

Ph.D., 

Ph.D., 

Senior 

Senior Biologist 

Agronomist /: dH, Ifi /,L/2 bl4 &, 

Environmental Risk Branch IV 

Environmental Fate and Effects Division (7507C) 

-7 

APPROVED 1, 

BY: Elizabeth Behl, Branch Chief 1 \p uk - 17 -c17 . / 

Environmental Risk Branch IV 

Environmental Fate and Effects Division (7507P) 

The Environmental Fate and Effects Division (EFED) has completed the draft environmental fate 

and ecological risk assessment in support of the Section 3 registration decision on the new 

herbicide pyrasulfotole (Bayer 309). The results of this screening-level risk assessment indicate 

that the proposed uses of pyrasulfotole at a maximum application rate of 0.045 lb a.i./acre have 

the potential for direct adverse effects for terrestrial and semi-aquatic dicotyledonous plants, 

some small mammals less than 35 g (chronic exposure), and listed freshwater vascular plants. 

Regarding listed species, EFED's screening level analysis shows the possibility of direct effects 

to listed aquatic vascular plants, terrestrial and semi-aquatic dicotyledonous plants, and mammals 

Text Searchable File
(chronic exposure). RQs are reduced to below Agency LOCs for listed aquatic vascular plants 

and mammals (listed and non-listed) with application rates of 10.030 lb a.i./acre and L 0.023 lb 

a.i./acre, respectively, indicating direct risks to these taxa would not be expected at these 

application rates. At this time, no Federally-listed taxa can be excluded from the potential for 

direct andlor indirect effects from the proposed uses of pyrasulfotole, since there is a potential for 

indirect effects to taxa that might rely on plants (even at a maximum application rate of 0.023 lb 

a.i./acre) andlor mammals for some stage of their life-cycle. Based on LOCATES, there is the 

potential for a total of 390 listed species to be directly affected by the proposed uses of 

pyrasulfotole, while 427 species may be indirectly affected by the use of the chemical. Details 

regarding the environmental fate, ecological effects and ecological risks associated with the 

current uses of pyrasulfotole can be found in the executive summary of the attached document. 

Data Gaps 

Table A.1. identifies the status of environmental fate and transport study requirements and Table 

A.2. identifies the status of ecological effects study requirements. The available environmental 

fate and transport data for pyrasulfotole are considered complete and are adequate for risk 

assessment purposes. 

Most of the ecological effects data gaps result from uncertainties surrounding potential ecological 

risks associated with the chronic effects of pyrasulfotole in estuarinelmarine invertebrates. 

Estuarinetmarine invertebrates (i.e., mysids) are at least 100 times more sensitive to pyrasulfotole 

on an acute exposure basis than all of the other aquatic animals tested and pyrasulfotole is 

persistent, however, no chronic data are available for this taxon. Risks to estuarinelmarine 

invertebrates are not expected with the current proposed use on cereal grains, in part because the 

use sites associated with cereal grains are largely outside of estuarinetmarine environments. 

However, if the uses for pyrasulfotole are expanded beyond cereal grains, the potential risk to 

estuarinelmarine invertebrates will need to be re-assessed. Therefore, we recommend that the 

toxicity studies for estuarinetmarine animals be held 'In Reserve' at this time. 

Additionally, because pyrasulfotole is persistent and has the potential to progressively bind to 

certain soils through time as it degrades and forms unextractable residues, there is the potential 

for pyrasulfotole (or residues of concern) to accumulate in the benthos at levels that could result 

in toxic exposure to benthic and epibenthic aquatic organisms, especially those that consume soil. 

The potential risk to benthic and epibenthic organisms could not be assessed here, however, 

because a lack of available toxicity data for these taxa. Due to the lack of data and the potential 

for adverse effects, we recommend that acute and chronic toxicity data on benthic animals be 

requested by the registrant. 

Labeling Recommendations 

According to the Label Review Manual, the following label statements are recommended: 

Environmental Hazards 

"Do not apply directly to water, or to areas where surface water is present or to intertidal 

areas below the mean high water mark. Do not contaminate water when disposing of 

equipment washwater or rinsate." 
Ground Water Advisory 

"Pyrasulfotole is known to leach through soil into ground water under certain conditions 

as a result of label use. Use of this chemical in areas where soils are permeable, 

particularly where the water table is shallow, may result in ground-water contamination." 

Surface Water Label Advisories 

"This product may contaminate water through drift of spray in wind. This product has a 

high potential for runoff for several months or more after application after application. 

Poorly draining soils and soils with shallow water tables are more prone to produce 

runoff that contains this product. A level, well maintained vegetative buffer strip between 

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

and springs will reduce the potential for contamination of water from rainfall-runoff. 

Runoff of this product will be reduced by avoiding applications when rainfall is 

forecasted to occur within 48 hours." 
ARE DATA 

ADEQUATE 

FOR RISK 

ASSESSMENT? 

Yes 

Table A. 1. Ecological Fate Studies for Pyrasulfotole. 

GUIDE- COMMENTS 

LINE 

Acceptable 

MRID 

46801 705 [Pyrazole-3- 14C] None 

AE03 17309: hydrolytic 

I degradation I 

161-2 1 46801706 1 ['4~-~~-~henyl] and I Acceptable 

STUDY TITLE 

Yes 

EPA 

CLASSIFICATION 

None 

[14~-3-pyrazole] 

AE03 17309: 

phototransformation in 

I water 

161-3 1 46801707 1 [~yrazole-3-I4C] I Acceptable Yes None 

AE03 17309: 

phototransformation on 

soil 

[~henyl-~-'~c]- and 

[pyrazole-3-14~]-~ 

03 17309: aerobic soil 

metabolism in a loamy 

sand soil of US origin 

under laboratory 

Acceptable Yes None 

162-1 Yes None 

03 17309: aerobic soil 

metabolism in a silt 

loam soil of US origin 

under laboratory 

4680 17 10 

I conditions at 25°C 

162-1 1 4680171 1 1 [~hen~l-UL-'~~] and I Supplemental The study was 

conducted on a 

foreign soil; 

upgradeable 

conditions at 25OC 

[~henyl-U-'~C]- and 

Yes 

Acceptable 

0317309: aerobic soil 

metabolism in a I European soil 

162-2 1 46801712 ] [Phenyl-U~-'~~l and I Accevtable Yes 

Yes 

None 

I 1 0317309: anaerobic soil I 

162-3 None 

I I 03 17309: anaerobic 1 

4680 17 14 

162-3 Yes None 

metabolism 

[P~~~~~-UL-'~C]AE 

1 1 03 17309: anaerobic I 

Acceptable 

4680 17 15 

I aquatic metabolism 

162-4 1 468017 13 1 [Pyraz01-3-'~~]~~ ( Acceptable Yes 

aquatic metabolism 

[~yrazole-3-'~C]AE 

None 

Acceptable 

03 17309 and [phenylUL-I~CIAE 03 17309: 

aerobic aquatic 

I metabolism 

163-1 1 4680 1703 1 Adsorption/desorption I Acceptable Yes None 

of AE 03 17309 on five 

soils and one sediment 
I GUIDE- I MRID I STUDY TITLE 

I in five soils 

164- 1 1 46801 716 1 Terrestrial field 

1 2004 

164- 1 1 46801717 1 Terrestrial field 

I I 

dissipation of AE 

03 17309 in North 

Dakota soil, 2004 

Terrestrial field 

dissipation of AE 

03 17309 in Washington 

soil. 2004 

dissipation of AE 

03 17309 in Kansas soil, 

Acceptable Yes 

EPA 

CLASSIFICATION 

Acceptable 

Y Acceptable 

ARE DATA 

ADEQUATE 

FOR RISK 

ASSESSMENT? 

Yes 

Table A.2. Ecological Effects Studies for Pyrasulfotole. 

GUIDE- I MRID I STUDY TITLE 1 EPA 

CLASSIFICATION 

( Bobwhite 

I 71-2 1 468017-3 1 1 Technical AE03 17309: 1 Acceptable 

1 

71-1 

71-2 

I I A Subacute Dietary I 

46801 7-29 

4680 17-30 

I 1 03 17309 on Northern I 

71-4 

Technical AE03 17309: 

An Acute Oral LDsO 

with Northern 

Bobwhite. 

Technical AE03 17309: 

A Subacute Dietary 

with Northern 

Acceptable 

Acceptable 

468017-32 

71-4 

4680 17-24 Acceptable 

468017-25 Acceptable 

LCSo with ~allards 

Effect of Technical AE 

468017-33 

03 17309 on Mallard 

Reproduction. 

The 96 Hour Acute 

Toxicity to the 

Rainbow Trout, 

Oncorhynchus mykiss, 

in a Static System; AE 

03 17309 Technical 

97.4% wlw (Amended 

Report). 

The 96 Hour Acute 

Toxicity to the Bluegill 

Sunfish, Lepomis 

macrochirus, in a Static 

System, AE 0317309 

ARE DATA 1 ADEQUATE 

1 FORRISK 

ASSESSMENT? 

Acceptable 

Yes 

Bobwhite Reproduction 

Effect of Technical AE 

Yes 

Acceptable 

I Yes 

Yes 

Yes 

Yes 

Yes 

7 COMMENTS 

None 
COMMENTS 

None 

None 

None 

None 

None 

None 

No negative control 

was tested 

None 

None 

None 

ARE DATA 

ADEQUATE 

FOR RISK 

ASSESSMENT? 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

EPA 

CLASSIFICATION 

Acceptable 

Acceptable 

Acceptable 

Acceptable 

Acceptable 

Acceptable 

Supplemental 

Acceptable 

Acceptable 

Acceptable 

STUDY TITLE 

Technical, 98.2% w/w 

(Amended Report) 

The 48-Hour Acute 

Toxicity to the Water 

Flea, Daphnia magna, 

in a Static System AE 

03 17309 Technical 

97.4% w/w 

AE 03 17309-Acute 

Toxicity to Eastern 

Oysters (Crassostrea 

virginica) Under FlowThrough Conditions 

AE 03 17309- Acute 

Toxicity to Mysids 

(Americamysis bahia) 

Under Static Conditions 

Acute Toxicity of AE 

03 17309 Technical to 

the Sheepshead 

Minnow (Cyprinodon 

variegates) Under 

Static Conditions. 

Chronic Toxicity of AE 

03 17309 Technical to 

the Daphnia magna 

Under Static Renewal 

Conditions. 

Early Life Stage 

Toxicity of AE 

03 17309 Technical to 

the Fathead Minnow 

(Primephales promelas) 

Under Flow-Through 

Conditions 

Contact toxicity (LD50) 

to honey bees (Apis 

mellifera L.), Substance 

technical 

Toxicity of AE 

03 17309 Technical to 

Duckweed (Lemna 

gibba G3) Under Static 

Conditions. 

Toxicity of AE 

03 17309 Technical to 

the Freshwater Diatom 

Navicula pelliculosa 

Toxicity of AE 

03 17309 Technical to 

the Green Alga 

GUIDELINE 

72-2 

72-3 

72-3 

72-3 

72-4 

72-4 

141-1 

850.4400 

850.5400 

850.5400 

MRID 

4680 17-2 1 

4680 17-22 

468017-23 

46801 7-26 

468017-27 

468017-28 

468017-35 

468017-36 

468017-38 

468017-37 
COMMENTS 

A NOAEC for 

biomass could not be 

determined due to 

significant inhibition 

at all treatment levels 

None 

None 

None 

ECZ5 values could not 

be determined for 

onion and sugar beet 

survival, and the 

reviewer was unable 

to statistically 

analyze plant height 

because the study 

authors only reported 

the range of values 

within each replicate 

and the treatment 

mean; no replicate 

mean values were 

reported. 

A NOAEC could not 

be determined for the 

most sensitive 

endpoint, cucumber 

dry weight. Inhibition 

in biomass at the 

lowest treatment 

level was 18%. 

GUIDELINE 

850.5400 

850.5400 

123-la 

123-la 

123- 1 b 

123- 1 b 

EPA 

CLASSIFICATION 

Supplemental 

Acceptable 

Acceptable 

Acceptable 

Supplemental 

Supplemental 

ARE DATA 

ADEQUATE 

FOR RISK 

ASSESSMENT? 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

MRID 

468017-39 

468017-40 

46801 9-26 

468019-36 

46801 9-27 

468019-37 

STUDY TITLE 

Pseudokirchneriella 

subcapitata (a.k.a. 

Selenastrum 

capricornutum). 

Toxicity of AE 

0317309 Technical to 

the Blue-Green Algae 

Anabaena jlos-aquaea 

Toxicity of AE 

03 17309 Technical to 

the Saltwater Diatom 

Skeletonema costatum. 

Non-target terrestrial 

plants: Seedling 

emergence and growth 

test (Tier 2) Suspoemulsion: 50+ 12.5 g/L 

(Code: AE 0317309 02 

SE06 A102) 

Non-target terrestrial 

plants: Seedling 

emergence and seedling 

growth test (Tier 2); AE 

0.3 17309+Mefenpyr diethyl+Bromoxynil 

(Code: AE 03 17309 03 

EC23 A8) 

Non-target terrestrial 

plants: Vegetative vigor 

test (Tier 2) AE 

03 17309 + Mefenpyr 

di-ethyl (AE F107892); 

Suspo-emulsion: 

50+ 12.5 g/L (Code: AE 

03 17309 02 SE06 

A102) 

Non-target terrestrial 

plants: Vegetative 

Vigor test (Tier 2), AE 

03 17309+Mefenpyr diethyl+Bromoxynil 

(Code: AE 03 17309 03 

EC23 A8) 
GUIDELINE 

850.6200 

850.6200 

NonGuideline 

NonGuideline 

EPA 

CLASSIFICATION 

Supplemental 

Supplemental 

Supplemental 

Supplemental 

MRID 

46801 7-41 

468017-42 

46801 7-43 

468017-34 

STUDY TITLE 

AE 03 17309, 

substance, technical 

(Code: AE 03 17309 00 

1C96 000 1): Acute 

Toxicity to Earthworms 

(Eisenia fetida) tested 

in Artificial Soil 

RF'A 203328, Acute 

Toxicity (14-Day) to 

Earthworms (Eisenia 

foetida) 

Isoxaflutole-RPA 

203328 (AE B197555): 

Reproduction toxicity 

to the earthworm 

Eisenia fetida in 

artificial soil 

Oral toxicity (LD50) to 

honey bees (Apis 

mellifera L.), Substance 

technical 

ARE DATA 

ADEQUATE 

FOR RISK 

ASSESSMENT? 

Yes 

Yes 

Yes 

Yes 

COMMENTS 

Non-guideline (EPA 

requires a 28-day 

test, this is a 14-day 

test) 

Non-guideline (EPA 

requires a 28-day 

test, this is a 14-day 

test) 

Non-guideline - This 

study was based on 

procedures of the IS0 

Guideline 11268-2 

"Soil quality-Effects 

of pollutants on 

earthworms (Eisenia 

fetida) Part 2: 

Determination of 

effects on 

reproduction" (July 

1998). 

Non-guideline 
Environmental Fate and Ecological Risk Assessment for the 

Registration of the New Chemical Pyrasulfotole (AE 0317309) 

Pyrasulfotole 

(5-hydroxy- 1,3 -dimethyl- 1 H-pyrazol-4-yl)[2-(methylsulfony1)-4- 

(trifluoromethyl)phenyl]methanone 

CAS NO. 365400- 1 1-9 

Prepared by: 

Melissa Panger, Ph. D.' U. S. Environmental Protection Agency 

Marietta Echeverrial Office of Pesticide Programs 

Megan Thynge -/ 2 - ~3 7 Environmental Fate and Effects Division 

Reviewed by: c 'Environmental Risk Branch IV 

Thomas M. Steeger, P~.D.' 2 Environmental Information Services Branch -, 

R. David Jones, P~.D.' 1200 Pennsylvania Ave., NW 

Mail Code 7507P 

Washington, DC 20460 
Environmental Fate and Ecological Risk Assessment for the 

Registration of the New Chemical Pyrasulfotole (AE 0317309) 

Pyrasulfotole 

(5-hydroxy- 1,3-dimethyl- 1 H-pyrazol-4-yl)[2-(methylsulfony1)-4- 

(trifluoromethyl)phenyl]methanone 

CAS NO. 365400- 1 1-9 

Prepared by: 

Melissa Panger, Ph. D.' 

Marietta ~cheverria' 

Megan ~h~n~e' 

Reviewed by: 

Thomas M. Steeger, P~.D.' 

R. David Jones, P~.D.' 

U. S. Environmental Protection Agency 

Office of Pesticide Programs 

Environmental Fate and Effects Division 

1 Environmental Risk Branch IV 

'~nvironmental Information Services Branch 

1200 Pennsylvania Ave., NW 

Mail Code 7507P 

Washington, DC 20460 
TABLE OF CONTENTS 

I . EXECUTIVE SUMMARY .......................................................................................... 5 

A . Nature of Chemical Stressor .................................................................... 5 

B . Conclusions - Exposure Characterization ............................................... 5 

C . Conclusions - Effects Characterization ................................................... 5 

D . Potential Risks to Non-target Organisms ................................................ 6 

E . Uncertainties and Data Gaps .................................................................... 8 

I1 PROBLEM FORMULATION .................................................................................. 10 

A . Stressor Source and Distribution ........................................................... 10 

1 . Source and Intensity ................................................................... 10 

2 . PhysicaVChemicaVFate and Transport Properties .................. 10 

3 . Pesticide Type, Class, and Mode of Action ............................... 11 

4 . Overview of Pesticide Usage ....................................................... 11 

B . Receptors ................................................................................................. 11 

1 . Aquatic and Terrestrial Effects ................................................. 11 

2 . Ecosystems at Risk ...................................................................... 12 

C . Assessment Endpoints ............................................................................. 12 

D . Conceptual Model ................................................................................... 14 

1 . Risk Hypotheses .......................................................................... 14 

2 . Diagram ........................................................................................ 14 

E . Analysis Plan ............................................................................................ 16 

1 . Preliminary Identification of Data Gaps and Methods ........... 17 

2 . Measures to Evaluate Risk Hypotheses and Conceptual Model 

....................................................................................................... 17 

a . Measures of Exposure ..................................................... 17 

b . Measures of Effect ........................................................... 18 

111 . ANALYSIS ........................................................................................................... 19 

A . Use Characterization ............................................................................... 19 

B . Exposure Characterization ..................................................................... 19 

1 . Environmental Fate and Transport Characterization ............ 23 

a . Degradation ..................................................... 24 

b . Mobility and Transport ....................................... 25 

c . Field Studies ..................................................... 25 

d . Degradates ...................................................... 25 

2 . Measures of Aquatic Exposure .................................................. 27 

a . Aquatic Exposure Modeling ........................................... 27 

b . Aquatic Exposure Monitoring and Field Data ............. 31 

3 . Measures of Terrestrial Exposure ............................................. 31 

a . Terrestrial Exposure Modeling ................................ 31 

C . Ecological Effects Characterization ......................................................... 32 

1 . Aquatic Effects Characterization .................................................. 35 

a . Aquatic Animals .................................................................. 35 

b . Aquatic Plants .................................................................... 36 

2 . Terrestrial Effects Characterization ............................................. 36 

a . Terrestrial Animals ............................................................. 36 
b . Terrestrial Plants ................................................................ 38 

3 . Toxicity of the Degradate Pyrasulfotole-Benzoic Acid 36 ............... 

IV . Risk Characterization .......................................................................................... 40 

A . Risk Estimation . Integration of Exposure and Effects Data ................. 40 

1 . Non-target Aquatic Animals and Plants ....................................... 42 

2 . Non-target Terrestrial Animals ..................................................... 43 

3 . Non-target Terrestrial and Semi-aquatic Plants .......................... 44 

B . Risk Description .......................................................................................... 45 

1 . Risks to Aquatic Organisms ........................................................ 46 

a . Animals ............................................................................. 46 

b . Plants ................................................................................ 47 

2 . Risks to Terrestrial Organisms ................................................... 48 

a . Animals ............................................................................. 48 

b . Plants ................................................................................ 49 

3 . Review of Incident Data .................................................................. 51 

4 . Federally Threatened and Endangered (Listed) Species Concerns 

....................................................................................................... 51 

a . Action Area ................................................................. 5 1 

b . Taxonomic Groups Potentially at Risk .......................... 52 

(1) . Discussion of Risk Quotients ............................. 52 

(2) . Probit Dose Response Relationship .................. 52 

(3) . Indirect Effects Analysis ..................................... 54 

(4) . Critical Habitat .................................................... 55 

(5) . Co-occurrence Analysis ...................................... 56 

C . Description of Assumptions, Limitations. Uncertainties. Strengths 

and Data Gaps ......................................................................................... 59 

V . References ................................................................................... 60 

LIST OF FIGURES: 

FIGURE 1: Conceptual Plan Diagram Depicting Sources of Exposure. Potential 

Receptors and Adverse Effects from the Proposed Uses of Pyrasulfotole ......... 16 

FIGURE 2 . Acres of Barley Grown By County in the United Stated in 2005 (based 

on information from USDA.NASS) ........................................................ 20 

FIGURE 3 . Acres of Wheat Grown By County in the United Stated in 2005 (based 

on information from USDA-NASS) ........................................................ 21 

FIGURE 4 . Acres of Oats Grown By County in the United Stated in 2005 (based on 

information from USDA.NASS) ............................................................ 22 

LIST OF TABLES: 

TABLE 1 . Listed Species Risks Associated with Potential Direct or Indirect Effects 

Due to the Proposed Applications of Pyrasulfotole on Cereal Grains ............... 8 

TABLE 2 . Taxonomic Groups and Test Species Evaluated for Ecological Effects in . 

Screening-Level Risk Assessments ......................................................... 12 

TABLE 3 . Acute and Chronic Measures of Effect .......................................... 19 

TABLE 4 . Application Information from the Proposed Pyrasulfotole Labels ........ 23 
TABLE 5 . Summary of Environmental Chemistry. Fate and Transport Properties 

of Pyrasulfotole ................................................................................. 24 

TABLE 6 . Summary of Crop Scenarios Used in Aquatic Exposure Modeling ....... 28 

TABLE 7 . PRZMIEXAMS Input Parameters for Aerial Application of Pyrasulfotole 

to Cereal Grains .............................................................................. -30 

Table 8 . Tier I1 Surface Water 1-in-10-Year Estimated Environmental 

Concentrations (EECs) of Pyrasulfotole from Cereal Grain Use (ppb) ............ 31 

TABLE 9 . EECs on Potential Food Items Following Label-Specified Applications of 

Pyrasulfotole Using the T-REX Model (ppm) ........................................... 32 

TABLE 10 . EECs on Plants Following Label-Specified Applications of 

Pyrasulfotole Using the TerrPlant Model (Ibs a.i./A). .................................. 32 

TABLE 11 . Summary of Specific Assessment Endpoints for Animals and Plants 

Considered in this Assessment .............................................................. 33 

TABLE 12 . Terrestrial Monocot and Dicot Endpoints (Ibs a.i./acre) from the 

Pyrasulfotole Seedling Emergence and Vegetative Vigor Studies ................... 39 

TABLE 13 . RPA 203328 Acute Toxicity Data for aVariety of Animals and 

Plants ............................................................................................. 40 

TABLE 14 . Agency Levels of Concern (LOC) .............................................. 42 

TABLE 15 . Aquatic Animal RQ Values for Exposure to Pyrasulfotole ................ 43 

TABLE 16 . Aquatic Plant RQ Values for Exposure to Pyrasulfotole .................. 43 

TABLE 17 . Avian RQ Values for Chronic Exposure to Pyrasulfotole ................. 43 

TABLE 18 . Mammalian RQ Values for Chronic Exposure to Pyrasulfotole ......... 44 

TABLE 19 . RQ Values for Terrestrial and Semi-Aquatic Plants Exposed to 

Pyrasulfotole .................................................................................... 45 

TABLE 20 . Comparison of RQ Values for Terrestrial and Semi-Aquatic Dicots 

Exposed to the AE 0317309 SE06 and AE 0317309 + Bromo formulations ....... 50 

TABLE 21 . Chance of an Individual Effect Corresponding to the Listed Species 

Acute LOCs Using a Probit Slope Response Relationship ............................ 54 

TABLE 22 . Listed Species Risks Associated with Potential Direct or Indirect 

Effects Due to the Proposed Applications of Pyrasulfotole on Cereal Grains .... 55 

TABLE 23 . Tabulation by State and Taxonomic Group of Listed Species that 

Occur in Counties with Potential Pyrasulfotole Use Sites ............................ 58 

LIST OF APPENDICES: 

APPENDIX A: ECOTOX Results ............................................................. 68 

APPENDIX B: Environmental Fate and Transport Study Details ...................... 69 

APPENDIX C: PRZMIEXAMS Output Data from the ND Wheat, OR Wheat, 

and TX Wheat Scenarios ..................................................................... 80 

APPENDIX D: Input Parameters and Results from T-REX ............................. 86 

APPENDIX E: TerrPlant Model ............................................................... 89 

APPENDIX F: Results from Submitted Eco Toxicity Studies for Pyrasulfotole ..... 91 

APPENDIX G: Input Parameters for AgDRIFT ............................................ 95 

APPENDIX H: Federally Listed Species that Co-Occur with Potential Pyrasulfotol 

Use Sites at the County-Level (Based on LOCATES) ................................ 102 
I. EXECUTIVE SUMMARY 

A. Nature of Chemical Stressor 

Pyrasulfotole is a new herbicide that is proposed for registration by the registrant Bayer 

Cropscience for use on wheat, barley, oats and triticale. Pyrasulfotole is a systemic 

herbicide that inhibits the enzyme 4-hydroxyphenylpyruvate dioxygenase (4-HPPD) and 

causes bleaching symptoms, necrosis, and ultimately death in susceptible plants. The two 

pyrasulfotole (AE 03 17309) end-use products being proposed for registration are AE 

03 17309 + Bromo Herbicide (an emulsifiable concentrate with 3.3% pyrasulfotole, 13.4% 

bromoxynil octanoate, and 12.9% bromoxynil heptanoate) and AE 03 17309 SE06 

Herbicide [a suspo-emulsion (consisting of suspension concentrates and oil-in-water 

emulsions) containing 4.4% pyrasulfotole]. Pyrasulfotole would be applied as a postemergent foliar spray once a year via ground, aerial, or sprinkler irrigation at a maximum 

rate of 0.045 lb a.i./acre according to the proposed label. 

B. Conclusions - Exposure Characterization 

Pyrasulfotole is highly soluble in water, has a low vapor pressure and low octonal-water 

partitioning coefficient. Therefore, volatilization from water and soil surfaces is not 

expected to be an important route of environmental dissipation and bioaccumulation is 

unlikely. Pyrasulfotole is stable to hydrolysis and photolysis and moderately susceptible 

to microbial degradation under aerobic conditions in soils. Pyrasulfotole is expected to 

be persistent under certain conditions and moderately mobile to mobile (FA0 

classification) in the environment. Major routes of dissipation include microbial 

degradation in soils, formation of unextractable residues in soils and sediments, and 

dilution. Depending on soil, site and meteorological conditions pyrasulfotole may be 

transported off-site via runoff, leaching and spray drift. There was one major degradate, 

pyrasulfotole-benzoic acid (RPA 203328, AE B197555), detected in the aerobic soil 

metabolism and terrestrial field dissipation studies. Based on available ecological effects 

data, exposure to pyrasulfotole-benzoic acid is not of risk concern, and, therefore, it is not 

assessed here. 

C. Conclusions - Effects Characterization 

Pyrasulfotole is classified as practically nontoxic to fish and freshwater invertebrates, 

slightly toxic to freshwater nonvascular plants, moderately toxic to marine nonvascular 

plants, highly toxic to estuarinelmarine invertebrates, and very highly toxic to aquatic 

vascular plants on an acute exposure basis. A freshwater fish early life-cycle 

reproductive study on fathead minnows resulted in a NOAEC of 0.58 mg a.i./L based on 

a reduction in total length. A chronic test for Daphnia resulted in a NOAEC of 12.8 mg 

a.i./L, based on the most sensitive endpoint, survival. 

Pyrasulfotole is classified as practically nontoxic to avian species on an acute oral basis 

and is practically nontoxic to slightly toxic to avian species on a subacute dietaryexposure basis. The lowest NOAEC in an avian reproduction study was for the mallard 
duck (1 67 mg a.i./kg diet), based on reduced male weight gain. Pyrasulfotole is classified 

as practically nontoxic to mammals on an acute oral basis. A two generation 

reproduction study on rats resulted in a NOAEL of 2.5 mag-bwlday based on delayed 

maturation and corneal opacity. Pyrasulfotole is classified as 'practically nontoxic' to 

non-target terrestrial insects. 

Results of the Tier I1 seedling emergence studies with the AE 03 17309 02 SE06 and AE 

03 17309 + Bromo formulations showed no measurable effects to monocots at any of the 

tested treatment levels. For dicots, the AE 03 17309 + Bromo formulation is more toxic 

than the AE 03 17309 02 SE06 formulation, however, because it is a mixture of different 

active ingredients, the results from the studies using this formulation cannot be used to 

specifically assess the risks of pyrasulfotole to plants. Therefore, the results from the AE 

03 17309 02 SE06 study (i.e., a NOAEC of 0.00039 lb a.i./A and an EC25 of 0.001 1 lb 

a.i./A based on tomato dry weight) are used to assess the effects of exposure to 

pyrasulfotole on seedling emergence in non-listed and listed dicots. 

Results of the Tier I1 vegetative vigor studies identify onion as the most sensitive 

monocot with decreased dry weight as the most sensitive endpoint affected (with the AE 

03 17309 02 SE06 formulation). The NOAEC and EC25 values for onion dry weight were 

0.0125 lbs a.i./A and 0.017 lbs a.i./A, respectively. No effects were seen in monocots in 

the vegetative vigor study with the AE 03 17309 + Bromo formulation. For dicots, 

although the AE 03 17309 + Bromo formulation (with a mixture of a.i.'s) is more toxic 

than the AE 03 17309 02 SE06 formulation, the results from the SE06 formulation (i.e., a 

NOAEC of 0.0.000797 lb a.i./A and an EC25 of 0.00081 lb a.i./A, based on tomato dry 

weight) are used to assess the effects of exposure to pyrasulfotole on vegetative vigor in 

non-listed and listed terrestrial dicots. 

D. Potential Risks to Non-target Organisms 

The results of this screening-level risk assessment indicate that the proposed uses of 

pyrasulfotole have the potential for direct adverse effects for terrestrial and semi-aquatic 

dicotyledonous plants, some small mammals less than 35 g (chronic exposure), and listed 

freshwater vascular plants. Risks to listed aquatic plants and mammals (listed and nonlisted), however, are not expected at application rates 10.040 lb a.i./acre and 50,023 lb 

a.i./acre, respectively. Therefore, if the proposed maximum application rate for 

pyrasulfotole was reduced to 0.023 lb a.i./acre, direct adverse effects from pyrasulfotole 

use would only be expected for terrestrial and semi-aquatic dicotyledonous plants. 

'Listed' species are those which are currently on the Federal list of endangered and 

threatened wildlife and plants. 

For dicots, the RQs ranged from 0.01 to 22.5 and from 0.56 to 62 for non-listed and listed 

species, respectively. Predictions based on the AgDRIFT model indicate that dicots more 

than 390 fi (using the AE 03 17309 02 SE06 formulation) and 2,126 ft (using the AE 

03 17309 + Bromo formulation) from the treated use area may be exposed by spray drift 

to pyrasulfotole at levels above the EC25. The mammalian RQs calculated for chronic 

exposure range from 0.01 to 1.87 for dose-based RQs using upper 9oth percentile Kenaga 
values. The RQs for three mammalian body-sizeldietary categories exceed the Agency's 

LOC for chronic exposure: 15 g and 35 g mammals that eat short grass (RQs = 1.87 and 

1.6, respectively) and 15 g mammals that eat broadleaf plants/small insects (RQ = 1.05). 

All mammalian chronic RQs drop to <1 at application rates of 10.023 Ib ailacre. 

The non-listed species LOC for aquatic vascular plants was not exceeded in any of the 

use scenarios modeled, however, the listed species LOC was exceeded (RQ = 1.05; based 

on exposure estimates using the TX Wheat scenario), indicating the potential for risk to 

listed aquatic vascular plants exposed to pyrasulfotole. The RQ for listed aquatic 

vascular plants drops to <1 at application rates of 10.040 lb a.i./acre. 

None of the aquatic animal RQs for chronic exposure exceeded the Agency's LOC, 

however, chronic toxicity data are not available for the most acutely sensitive aquatic 

animal taxon (i.e., estuarinelmarine invertebrate). Although the chronic toxicity of 

pyrasulfotole to estuarinelrnarine invertebrates is uncertain, given that: (1) the potential 

use sites for the proposed uses largely fall outside of estuarinelrnarine environments, with 

the possible exceptions of California and the mid-Atlantic states; (2) the aquatic EECs 

used in this assessment are based on a static water-body with no outlet, and, thus, are 

likely higher than concentrations expected in estuarinelrnarine environments; and (3) 

estuarinelrnarine invertebrates would need to be 1,293 times more sensitive to 

pyrasulfotole than freshwater invertebrates on a chronic-exposure basis to exceed the 

Agency's chronic risk LOC, risks to estuarinelmarine invertebrates from chronic 

exposure to pyrasulfotole are not expected. 

Regarding listed species, EFED's screening level analysis shows the possibility of direct 

effects to listed aquatic vascular plants, terrestrial and semi-aquatic dicotyledonous 

plants, and mammals (chronic exposure). For indirect effects, all other taxa will be 

considered since there is a potential for indirect effects to taxa that might rely on plants 

and/or mammals for some stage of their life-cycle. Therefore, at this time, no Federallylisted taxa can be excluded from the potential for direct andlor indirect effects from the 

proposed uses of pyrasulfotole (see Table 1). LOCATES identified a total of 817 listed 

species that overlapped at the county-level with areas where wheat, barley, oats, andlor 

triticale are grown. Among these species, 3 18 are dicots, 13 are aquatic monocots, and 

59 are mammals. Therefore, at the county-level, there is the potential for a total of 390 

listed species to be directly affected by pyrasulfotole use, while 427 species may be 

indirectly affected by the use of the chemical. 
TABLE 1. Listed Species Risks Associated with Potential Direct or Indirect Effects 

Due to the Proposed Applications of Pyrasulfotole on Cereal Grains. 

I I 

LISTED TAXON I DIRECT EFFECTS I INDIRECT EFFECTS 

Terrestrial and semi-aquatic 

plants - monocots I 

Terrestrial and semi-aquatic 

plants - dicots 1 Yes 

Insects I No I yes1 

Birds 1 No 1 yes' 

Terrestrial phase amphibians 

Aquatic plants I Yes I yes' 

No 

Reptiles 

Mammals 

Freshwater crustaceans 

No 

Yes (chronic) 

Freshwater fish 

Aquatic phase amphibians 

Mollusks No 

----- 

yes' 

yes' 

Marinelestuarine crustaceans I No I yes1 

No 

No 

I I 

 he nonlisted LOC was exceeded for terrestrial and semi-aquatic plants (dicots), the listed LOC was 

exceeded for aquatic vascular plants, and the chronic risk LOC was exceeded for some small mammals 

(535 g) . Therefore, the potential for adverse effects to those species that rely either on a specific plant or 

animal species (specifically aquatic vascular plants, terrestriallsemi-aquatic dicots, or mammals) or 

multiple plant or animal species (specifically terrestriallsemi-aquatic dicots and mammals) cannot be 

precluded. Indirect effects may include general habitat modification, host plant loss, and food supply 

disruption. 

yes' 

yes' 

E. Uncertainties and Data Gaps 

There is no evidence of pyrasulfotole degradation in aquatic environments. As such, 

pyrasulfotole was assumed stable in the ecological pond used to estimate aquatic 

exposure concentrations. Since the ecological pond (used in our modeling) has no outlet, 
there was a modeled accumulation of pyrasulfotle in the pond throughout the 30 year 

simulations. In the case of persistent compounds, a 1-in-10 year EEC does not reflect 

varying meteorological conditions that are expected once every ten years, since the yearly 

peaks are not independent but are actually correlated to the previous year's peak 

concentration. This results in acute and chronic exposure concentrations that are very 

similar (i.e, < 2% difference between peak and 90-day average EECs). Pyrasulfotle 

concentrations in flowing water bodies are not expected to accumulate from year to year 

because of downstream dilution. Risk to aquatic plants resulting from accumulation of 

pyrasulfotle fiom multiple years of application is not likely in flowing systems. 

Even though pyrasulfotole is very soluble and moderately mobile to mobile based on the 

results of batch equilibrium studies, in aerobic soil metabolism studies unextractable 

residues were identified at maximums of 35-62% of applied radioactivity in three soils. 

The unextractable residues are uncharacterized and it is uncertain whether they consist of 

degradates of risk concern. Under sterile conditions these unextractable residues were 

not formed suggesting that the formation of them is microbially mediated. Aerobic soil 

metabolism half-lives were estimated based on parent concentrations alone (excluding 

unextractable residues). To the extent that these unextractable residues are of risk 

concern, the estimated half-lives will be underestimated compared to a total toxic residue 

approach for estimating half-lives. However, given the persistence of pyrasulfotle parent 

only, a total toxic residue approach for calculating aerobic soil metabolism half-life 

would not impact PRZMIEXAMS modeled EECs appreciably. 

Because pyrasulfotole is persistent and has the potential to progressively bind to certain 

soils through time as it degrades and forms unextractable residues, there is the potential 

for pyrasulfotole (or residues of concern) to accumulate in the benthos at levels that could 

result in toxic exposure to benthic and epibenthic aquatic organisms, especially those that 

consume soil. The potential risk to benthic and epibenthic organisms could not be 

assessed here, however, because a lack of available toxicity data for these taxa. 

Additionally, estuarinelrnarine invertebrates (i.e., mysids) are considerably more sensitive 

to pyrasulfotole on an acute exposure basis than the other aquatic animals tested, 

however, no toxicity data for chronic exposure are available for estuarinelmarine 

invertebrates. Because there is the potential for pyrasulfotole to accumulate in the 

benthos, as discussed above, the chemical could pose a chronic risk to benthic and 

epibenthic organisms (including some estuarinelrnarine invertebrates). However, given 

that: (1) the potential use sites for pyrasulfotole largely fall outside of estuarinelmarine 

environments; (2) the aquatic EECs used in this assessment are likely higher than the 

concentrations expected in most estuarinelmarine environments because they are based 

on a static water-body with no outlet; and (3) estuarinelmarine invertebrates would need 

to be 1,293 times more sensitive to pyrasulfotole than freshwater invertebrates to exceed 

the Agency's chronic risk LOC, risks to estuarinelmarine invertebrates from chronic 

exposure to pyrasulfotole are not expected. However, the lack of data on the chronic 

toxicity of pyrasulfotole to estuarinelrnarine invertebrates adds uncertainty to this risk 

assessment. 
I1 PROBLEM FORMULATION 

The purpose of this assessment is to evaluate the environmental fate and ecological risks 

for the registration of the new chemical pyrasulfotole (also known as AE 03 17309; (5- 

hydroxy- l,3-dimethyl- 1 H-pyrazol-4-yl)(2-mesyl-4-trifluoromethylphenyl)methanone) 

(PC Code: 000692). As a new herbicide being proposed for use in the United States, 

EPA is required under the Federal Insecticide Fungicide and Rodenticide Act (FIFRA) to 

ensure that pyrasulfotole does not have the potential to cause unreasonable adverse 

effects to the environment. 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 in order to ensure that the registration of pyrasulfotole is not 

likely to jeopardize the continued existence of such listed species or adversely modify 

their habitat. To these ends, this assessment follows EPA guidance on conducting 

ecological risk assessments (USEPA 1998) and the Office of Pesticide Program's policies 

for assessing risk to non-target and listed organisms (USEPA 2004). 

Among the end products of the EPA pesticide registration process is a determination of 

whether a product is eligible for registration and, if so, a description of how the product 

may be used. A label represents the legal document which stipulates how and where a 

given pesticide may be used. End-use labels describe the formulation type, acceptable 

methods of application, where the product may be applied, and any restrictions on how 

applications may be conducted. Thus, the use, or potential use, described by the 

pesticide's labels is considered "the action" being assessed. This assessment is in support 

of the new chemical registration of pyrasulfotole. 

A. Stressor Source and Distribution 

1. Source and Intensity 

Pyrasulfotole, a systemic herbicide, is a new chemical that is undergoing registration (as 

the active ingredient in two end-use products) by the registrant Bayer Cropscience. The 

two pyrasulfotole (AE 03 17309) end-use products being proposed for registration in the 

United States are AE 03 17309 + Bromo Herbicide [with the following active ingredients 

(a.i.): 3.3% pyrasulfotole, 1 3.4% bromoxynil octanoate, and 12.9% bromoxynil 

heptanoate] and AE 0317309 SE06 Herbicide [the only a.i. is pyrasulfotole (4.4%)]. 

According to the proposed labels, both products would be used to control broadleaf 

weeds in wheat, barley, oats and triticale (an artificial hybrid of rye and wheat). 

Pyrasulfotole would be applied as a post-emergent foliar spray via ground, aerial, or 

sprinkler irrigation application (limited to AE 03 17309 + Bromo Herbicide for 

application to wheat and barley). 

2. PhysicaUChemicaYFate and Transport Properties 

Pyrasulfotole is expected to be persistent under certain conditions and mobile to 

moderately mobile (FA0 classification) in the environment. There is no evidence of 
degradation in aquatic environments. Major routes of dissipation include microbial 

degradation in soils, formation of non-extractable residues in soils and sediments, and 

dilution. 

3. Pesticide Type, Class, and Mode of Action 

Pyrasulfotole is a phenyl pyrazolyl ketone herbicide. According to a risk assessment 

conducted by Bayer Cropscience (MRID 468019-47), pyrasulfotole inhibits the enzyme 

4-hydroxyphenylpyruvate dioxygenase (4-HPPD), and, thus, blocks the phenylquinone 

biosynthesis pathway in plants which leads to a decrease in carotenoids. Therefore, 

pyrasulfotole inhibits photosynthesis and pigment synthesis and causes bleaching 

symptoms, necrosis, and ultimately death in susceptible plants, especially those with 

young and still expanding leaves. Pyrasulfotole is mobile in the symplast (phloem) and 

apoplast (xylem) plant transport systems, and plant exposure is primarily through leaf 

uptake and translocation to the target site; only low amounts are taken up via the root 

system. Pyrasulfotole is intended to target dicotyledonous plants. The tolerance of cereal 

crops to pyrasulfotole is likely related to the faster metabolic degradation of the herbicide 

when compared to susceptible dicots. 

4. Overview of Pesticide Usage 

Since this is a new chemical, the Agency does not have any usage information for 

pyrasulfotole. The proposed registration is for wheat, barley, oats, and triticale. 

Pyrasulfotole is a post emergence herbicide that is applied as a foliar spray (via ground, 

aerial, or sprinkler irrigation) one time a year at a maximum application rate of 0.045 Ib 

a.i./A. There are two pyrasulfotole end-use products being proposed for registration in 

the United States for use on wheat, barley, oats, and triticale. The two proposed 

formulations are AE 03 17309 + Bromo Herbicide (an emuslsifiable concentrate 

containing 3.3% pyrasulfotole) and AE 03 17309 SE06 Herbicide (a suspo-emulsion 

containing 4.4% pyrasulfotole). 

B. Receptors 

1. Aquatic and Terrestrial Effects 

Table 2 gives examples of taxonomic groups and species tested to help understand 

potential ecological effects of pesticides to non-target organisms. 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. 
TABLE 2. Taxonomic Groups and Test Species Evaluated for Ecological Effects in 

Screening-Level Risk Assessments. 

I Dicots - soybean (Glycine max) 

Aquatic plants and algae I Duckweed (Lemna gibba) 

Taxonomic Group 

~irds' 

Mammals 

Insects 

Freshwater fishz 

Freshwater invertebrates 

Estuarinelmarine fish 

Terrestrial plants" 

I Green algae (Selenastrum capricornutum) 

I Birds rmresent surrogates for amphibians (terrestrial ~hase) and re~tiles. 

Example(s) of Representative Species 

Mallard duck (Anas platyrhynchos) 

Bobwhite quail (Colinus virginianus) 

Laboratory rat (Rattus norvegicus) 

Honey bee (Apis mellifera L.) 

Bluegill sunfish (Lepomis macrochirus) 

Rainbow trout (Oncorhynchus mykiss) 

Water flea (Daphnia magna) 

Sheepshead minnow (Cyprinodon variegatus) 

Monocots - corn (Zea mays) 

- . , 

Freshwater fish may be surrogates for amphibians (aquatic phase). 

Four species of two families of monocots, of which one is corn; six species of at least four dicot families, of which 

one is soybeans. 

2. Ecosystems Potentially at Risk 

The ecosystems potentially at risk include the areas adjacent to the application sites and 

water bodies adjacent to the application sites and downstream. In addition, organisms 

that use the application site as part of their habitat (e.g., birds foraging for insects within 

application areas) are also considered to be part of the ecosystems potentially at risk. 

C. Assessment Endpoints 

FIFRA Part 158 guideline toxicity tests (CFR 40 $ 158.202,2002) are intended to 

determine pesticidal effects on a variety of organisms, including birds, mammals, fish, 

terrestrial and aquatic invertebrates, and plants. These tests include both short-term and 

long-term exposure periods and evaluate the survival, reproduction, and/or growth of 

laboratory species. The studies, when available, are used to evaluate the potential of a 

pesticide to cause adverse effects, to determine whether further testing is required, and to 

determine the need for precautionary label statements to minimize the potential adverse 

effects to non-target animals and plants (CFR 40 $1 58.202,2002). 

Assessment endpoints are intended to represent valued attributes of the environment that, 

if detrimentally altered, could pose a risk to the environment. The assessment endpoints 

of this ecological risk assessment include terrestrial and aquatic animal and plant 

mortality following acute exposure to pyrasulfotole and terrestrial and aquatic animal 

reproduction, growth and survival effects from chronic exposure to pyrasulfotole. 

Surrogate species are used to represent all fi-eshwater fish (2000-t) and bird (680+) 

species in the United States. For mammals, acute studies are usually limited to the 

Norway rat or the house mouse. Usually data fi-om estuarine/marine testing is limited to 

a crustacean, a mollusk, and a fish. The assessment of risk or hazard makes the 

assumption that avian toxicity is similar to terrestrial-phase amphibians and reptiles, 

unless more appropriate data are available. The same assumption is made for fish and 
aquatic-phase amphibians. The most sensitive toxicity endpoints are used from surrogate 

test species to estimate treatment-related direct effects on mortality and reproductive and 

growth assessment endpoints. 

For terrestrial and semi-aquatic plants, the screening assessment endpoints for non-target 

species (crops and non-crop plant species) are based on the emergence of seedlings and 

vegetative vigor of annuals. Measures of effect for this assessment focus on impacts on 

plant emergence and/or on active growth. 

For aquatic plants, the assessment endpoint is the maintenance and growth of standing 

crop or biomass. Measures of effect for this assessment focus on nonvascular, e.g., algae, 

and vascular plant, e.g., duckweed (Lemna gibba), growth rates and biomass 

measurements. 

The Agency acknowledges that pesticides have the potential to exert indirect effects upon 

listed organisms by, for example, perturbing forage or prey availability, altering the 

extent of nesting habitat, and creating gaps in the food chain. In conducting a screen for 

indirect effects, the endpoints for each taxonomic group are used to make inferences 

concerning the potential for indirect effects upon listed species that rely upon non-listed 

organisms as resources critical to their life cycle. 

The endpoints are typically derived from registrant-submitted studies which have 

undergone 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). For 

more details on EFED7s study classification system and study guidelines, see USEPA 

2004. 

Assessment endpoints can also be derived from the open literature. Guidelines for 

incorporation of open literature into ecological risk assessments are described in USEPA 

(2004). Toxicity data from the open literature are identified via the ECOTOX search 

engine, maintained by EPA/ORD. In order to be included in the ECOTOX database, 

papers must meet several criteria (again, see USEPA 2004 for details). Data that pass the 

ECOTOX screen are evaluated relative to the data provided by the registrant, and may be 

incorporated qualitatively or quantitatively into the risk assessment. Specific studies may 

warrant inclusion in the risk assessment when: 

(I) tested endpoints are more sensitive than those in registrant data; 

(2) the test data are based on under represented taxa; 

(3) the data include ecologically relevant endpoints not normally evaluated in 

registrant studies 

ECOTOX identified a total of four pyrasulfotole studies from the open literature, all of 

which were rejected by ECOTOX because they were not written in English (i.e., they 

were written in German) (see APPENDIX A). Therefore, no open literature studies were 

reviewed for assessment endpoints. 
Although all endpoints are measured at the individual level, they can provide some 

insight about the potential for adverse effects at higher levels of biological organization 

(e.g. populations and communities). For example, pesticide effects on individual 

survivorship have important implications for both population rates and habitat carrying 

capacity. 

D. Conceptual Model 

The conceptual model used to depict the potential ecological risk associated with 

pyrasulfotole is fairly generic and assumes that as a systemic herbicide, pyrasulfotole is 

capable of affecting terrestrial and aquatic organisms (animals and plants) provided 

environmental concentrations are sufficiently elevated as a result of proposed label uses. 

Additionally, based on a preliminary risk screening indicating that pyrasulfotole is highly 

toxic to some plants, the hypothesis for the risks of pyrasulfotole to non-target organisms 

(depicted in Figure 1) focuses on aquatic and terrestrial environments. Therefore, we 

will consider potential exposure as a result of direct applications, spray drift, and runoff. 

1. Risk Hypotheses 

For this assessment, the risk to non-target organisms is based on potential effects from 

the application of pyrasulfotole to the environment. The Agency presumes the following 

risk hypothesis for this screening level assessment: 

Based on mode of action and the sensitivity of non-target aquatic and terrestrial 

species (especially plants), the proposed agricultural uses of pyrasulfotole have 

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

aquatic animals and plants through direct application, spray drift and/or runoft 

In order for a chemical to pose an ecological risk, it must reach non-target organisms at 

concentrations found to cause adverse effects. The assessment of ecological exposure 

pathways in this assessment includes an examination of the source and potential 

migration pathways to pyrasulfotole exposure, and the determination of potential adverse 

effects on non-target species. 

2. Diagram 

Application methods for pyrasulfotole involve foliar spray applications via ground, aerial, 

and sprinkler irrigation. Ecological receptors that may potentially be exposed to 

pyrasulfotole include terrestrial and semi-aquatic wildlife (i.e., mammals, birds, 

amphibians, terrestrial invertebrates, and reptiles) and plants. In addition, aquatic 

receptors (e.g., freshwater and estuarinelmarine fish and invertebrates, amphibians, and 

plants) may also be exposed as a result of potential movement of pyrasulfotole via spray 

drift andlor runoff from the site of application to aquatic environments. The assessment 

following the process depicted in Figure 1 forms the basis for identifying potential 

endpoints, stressors, and ecological effects associated with pyrasulfotole use. 
This assessment does not take into account atmospheric transport in estimating 

environmental concentrations, nor does it account for ingestion of pyrasulfotole residues 

by animals in drinking water or contaminated grit, ingestion through preening activities, 

or uptake through inhalation or dermal absorption by terrestrial animals. Exposure to 

terrestrial animals is based primarily on dietary consumption of foliar residues while 

aquatic assessments assume that all major potential routes of direct exposure are 

accounted for. 
Stressor I Pyrasulfotole applied as a groundaerial spray to cereal grains I 

Birds, Mammals, 

Reptiles, Terrestrial 

Phase Amphibians 

Aquatic 

Invertebrates 

Vertebrates 

1 

Individual 

vertebrates and 

invertebrates 

Reduced survival 

or reproduction 

I 

1 1 

FIGURE 1: Conceptual Plan Diagram Depicting Sources of Exposure, Potential 

Receptors and Adverse Effects from the Proposed Uses of Pyrasulfotole. 

Source/ 

Transport 

E. Analysis Plan 

Spray Direct Application Runoff 

Drift A To Field 

As with any pesticide, there is concern regarding the potential effects pyrasulfotole use 

may pose to non-target animals and plants. This document characterizes the 

environmental fate of pyrasulfotole to assess whether proposed label uses of 

pyrasulfotole on wheat, barley, oats and triticale provide a means of exposure to nontarget species. Additionally, the toxicity of pyrasulfotole is characterized, then both 

potential exposure and effects are integrated to estimate the likelihood of adverse effects 

(risk) to non-target Federally listed (endangered or threatened) and non-listed animals 

and plants that could potentially impact the registration decision of pyrasulfotole under 

the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), the Food Quality 

Protection Act (FQPA), and the Endangered Species Act (ESA). 

Pathways 

A 

Source1 

Exposure 

Media 

Terrestrial Food Ripariad Receiving 

Items (foliage, fruit, Wetland Water Body/ 

insects, seeds) FoliageISoil Sediment 

I 

4 1 

Direct contact/ Direct contact/ Exposure Ingestion Root Uptake Root Uptake uptake/ Gill1 

Route Integument Adsorption Uptake 

Terrestrial Wetland1 Aquatic 1 

Receptors Upland Riparian Plants 

Plants Plants 

Attribute Individual Animals Individual Plants 

Changes Reduced survival Reduced survival, 

or reproduction growth, or reproduction Reduced 

population 

growth 
The maximum proposed label application rates for use of pyrasulfotole on wheat, barley, 

oats, and triticale were selected for modeling environmental concentrations for this 

screening-level deterministic (risk-quotient based) assessment. The most sensitive 

toxicity endpoints from surrogate test species are used to estimate treatment-related 

effects on growth, and survival. Estimated environmental concentrations (EECs) used in 

terrestrial and aquatic ecological risk assessments are based solely on pyrasulfotole 

parent compound, although the potential effects of the degradate RPA 203328 are 

considered (see page 37). 

In the following sections, we characterize the use, environmental fate, and ecological 

effects of pyrasulfotole and, using a risk quotient (ratio of exposure concentration to 

effects concentration) approach, we estimate the potential for adverse effects on nontarget terrestrial and aquatic animals and plants. Although risk is often defined as the 

likelihood and magnitude of adverse ecological effects, the risk quotient-based approach 

does not provide a quantitative estimate of likelihood and/or magnitude of an adverse 

effect. Such estimates may be possible through a more refined, probabilistic assessment; 

however, they are beyond the scope of this screening-level assessment. 

1. Preliminary Identification of Data Gaps and Methods 

No preliminary data gaps or method issues that would preclude a risk assessment were 

identified. 

2. Measures to Evaluate Risk Hypotheses and Conceptual Model 

a. 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 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- 1 0 year 2 1 -day mean concentration is 

used for assessing aquatic invertebrate chronic exposure; and the1 -in- 10 year 60-day 

mean concentration is used for assessing chronic exposure for fish (and aquatic-phase 

amphibians). The terrestrial measure of exposure for vertebrate and invertebrate animals 

is the upper 9oth percentile concentration normalized for application rates on various 

dietary items. 

Exposure for terrestrial plants inhabiting dry and semi-aquatic areas (i.e., low-lying wet 

areas that may dry up at times throughout the year) is based on the following: 

(1) the pesticide's water solubility and the amount of pesticide present on the soil 

surface and its top one centimeter, 

(2) potential "sheet runoff" (one treated acre to an adjacent acre) for dry areas, 
(3) potential "channel runoff' (1 0 acres to a distant low-lying acre) for semiaquatic or wetland areas, 

(4) fraction runoff values of 0.01, 0.02, and 0.05 for water solubilities of <lo, 10- 

100, and < 100 ppm, respectively, and 

(5) an assumption of 1 % spray drift for ground application and 5% for aerial, 

airblast, forced air, and spray chemigation applications. 

The registrant has provided a suite of studies pertinent to most Subdivision N guidelines, 

which provide environmental fate data for these measures of exposure. 

b. Measures of Effect 

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

conducted with a limited number of surrogate species. The test species are not intended 

to be representative of the most sensitive species but rather are selected based on their 

ability to thrive under laboratory conditions. The acute measures of effect routinely used 

for listed and non-listed animals in screening level assessments are the LDS0, LCs0 or 

ECS0, depending on taxa (see Table 3). LD stands for "Lethal Dose", and LDS0 is the 

amount of a material, given all at once, that is estimated to cause the death of 50% of a 

group of test organisms. LC stands for "Lethal Concentration" and LCs0 is the 

concentration of a chemical that is estimated to kill 50% of a sample population. EC 

stands for "Effective Concentration" and the ECS0 is the concentration of a chemical that 

is estimated to produce some measured effect in 50% of the test population. Endpoints 

for chronic measures of exposure for listed and non-listed animals are the NOAEL or 

NOAEC. NOAEL stands for "No Observed-Adverse-Effect-Level" and refers to the 

highest tested dose of a substance that has been reported to have no harmful (adverse) 

effects on a test population. The NOAEC (i.e., "No-Observed-Adverse-EffectConcentration") is the highest test concentration at which none of the observed results 

were statistically different from the control. For non-listed plants, only acute exposures 

are assessed (i.e., ECI5 for terrestrial plants and ECS0 for aquatic plants). For listed 

terrestrial plants the Agency uses the ECS or NOAEC (see Table 3). 

Consistent with EPA test guidelines, the registrant has provided a suite of ecological 

effect data that comply with good laboratory testing requirements. 
Aquatic Animals (Freshwater.fish 

and inverts. and estuarine/marine 

fish and inverts.) 

TABLE 3. Acute and Chronic Measures of Effect. 

Terrestrial Animals 

Birds 

TAXA ASSESSMENT 

Acute 

MEASURE OF EFFECT 

Lowest tested ECso or LCso (acute toxicity tests) 

Chronic 

I 

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

Acute/Subacute Lowest LDS0 (single oral dose) and LCso (subacute 

dietary) 

Chronic Lowest NOAEC (2 1-week reproduction test) 

I Terrestrial Animals Mammals 

I I 

I 

Acute 

Chronic 

Plants 

Terrestrial non-listed (monocots 

and dicots) 

Lowest EC5 or NOAEC (seedling emergence and 

vegetative vigor) 

Lowest LD50 (single oral dose test) 

Lowest NOAEC (two-generation reproduction test) 

Plants 

Terrestrial listed (monocots and 

dicots) 

I 

Acute 

Acute 

111. ANALYSIS 

Lowest EC2, (seedling emergence and vegetative vigor) 

Plants 

Aquatic (vascular and algae) 

A. Use Characterization 

The proposed pyrasulfotole registration is for wheat, barley, oats, and triticale. Based on 

National Agricultural Statistics Service (NASS) 2006 data, approximately 3,500,000 

acres of barley; 57,900,000 acres of wheat; and 4,300,000 acres of oats are planted each 

year in the United States (see Figs. 2,3, and 4). The most recent NASS report available 

for triticale is from 2002 (no map is available). According to this report, a total of 20,292 

acres of tricale was grown in 27 U.S. states in 2002. The state with the most acreage 

grown was Kansas (6,588 acres) followed by Washington (2,288 acres), Texas (2,032 

acres), Oregon (1,869 acres) and Nebraska (1,563 acres). The remaining states each grew 

less than 1,000 acres of triticale. These represent potential markets for pyrasulfotole in 

the United States. 

Acute Lowest EC50 
Barhy 2005 

Planted Acres by County 

FIGURE 2. Acres of Barley Grown By County in the United Stated in 2005 (based 

on information from USDA-NASS). 
All Wheat 2005 

Planted Acres by County 

FIGURE 3. Acres of Wheat Grown By County in the United Stated in 2005 (based 

on information from USDA-NASS). 
Oab m5 

Planted Acm try County 

FIGURE 4. Acres of Oats Grown By County in the United Stated in 2005 (based on 

information from USDA-NASS). 

Pyrasulfotole, a post emergence herbicide, is applied as a foliar spray (via ground, aerial, 

or sprinkler irrigation) to actively growing cereal crops from one leaf up to flag leaf 

emergence (approximately 7-45 days post emergence for spring wheat and 7-2 10 days 

post emergence for winter wheat). There are two pyrasulfotole end-use products being 

proposed for registration in the United States: AE 03 17309 + Bromo Herbicide (an 

emuslsifiable concentrate with the following a.i.: 3.3% pyrasulfotole, 13.4% bromoxynil 

octanoate, and 12.9% bromoxynil heptanoate) and AE 03 17309 SE06 Herbicide (a suspoemulsion containing 4.4% pyrasulfotole, and no other active ingredients). According to 

the proposed labels, pyrasulfotole can be applied at a single maximum application 

ratelyear of 0.045 lb ailacre for ground and aerial applications and 0.037 lb a.i./acre for 

sprinkler irrigation application (limited to use on wheat and barley) (see Table 4). Only 

one application per year is allowed. 
TABLE 4. Application Information from the Proposed Pyrasulfotole Labels. 

PRODUCT (% a.i.) 1 USES 1 APPLICATION I MAX. I MAX. NUMBER 

B. Exposure Characterization 

AE 03 17309 + Bromo 

Herbicide (3.3%) 

AE 03 17309 SE06 

Herbicide (4.4%) 

' The application rate on the 

1. Environmental Fate and Transport Characterization 

Pyrasulfotole is highly soluble in water (69 g/L), has a low vapor pressure (6.8 x 1 o-~ Pa) 

and low octonal-water partitioning coefficient (0.04). Therefore, volatilization from 

water and soil surfaces is not expected to be an important route of environmental 

dissipation and bioaccumulation is unlikely. Pyrasulfotole is stable to hydrolysis and 

photolysis and moderately susceptible to microbial degradation under aerobic conditions 

in soils. Pyrasulfotole is expected to be persistent under certain conditions and 

moderately mobile to mobile (FA0 classification) in the environment. Major routes of 

dissipation include microbial degradation in soils, formation of unextractable residues in 

soils and sediments, and dilution. Depending on soil, site and meteorological conditions 

pyrasulfotole may be transported off-site via runoff, leaching and spray drift. Table 5 

summarizes the environmental chemistry, fate and transport properties of pyrasulfotole. 

Further details on the environmental fate and transport studies are found in APPENDIX 

B. 

glcc; the fonnulation is 3.3% pyrasulfotole and a max application rate of 15 oz of formulated productlacre is allowed. ' The application rate on the label was converted to Ibs a.i./acre based on the following: The formulated product density = 1.141 1 

glcc; the formulation is 4.4% pyrasulfotole and a lnax application rate of 13.7 oz of formulated productlacre is allowed. 

Wheat 

Barley 

Oats 

Triticale 

Wheat 

Barley 

Oats 

Triticale 

label was converted to Ibs 

METHODS 

Ground 

Aerial 

Sprinkler Irrigation ................................................ 

Ground 

Aerial 

Sprinkler Irrigation ................................................. 

Ground 

Aerial ................................................ 

Ground 

Aerial 

Ground 

Aerial 

................................................ 

Ground 

Aerial ................................................ 

Ground 

Aerial ................................................ 

Ground 

Aerial 

a.i./acre based on the following: 

APPLICATION 

RATE/ YEAR 

0.037 lb a.i./acrel 

0.045 lb a.i./acre2 

The formulated product density 

OF 

APPLICATIONS1 

YEAR 

1 

1 

= 1.141 7 
Selected Phvsical/Chemical Parameters 

TABLE 5. Summary of Environmental Chemistry, Fate and Transport Properties 

of Pyrasulfotole. 

Molecular weight 1 362.3 glmol 1 

REFERENCE1 

COMMENTS PARAMETER 

PC code 

CAS NO. 

Chemical name 

Chemical formula 

VALUE 

000692 

365400-1 1-9 

(5-hydroxy- l,3-dimethylpyrazol-4-yl)(a,a,a-trifluoro2-mesyl-p-toly1)methanone 

C~HI~C~~N 

Product chemistry; very 

soluble 

Water solubility (20 "C) 

pH 4 

pH 7 

VH 9 

Vapor pressure 

4.2 g/L 

69 g/L 

49 g/L 

Product chemistry; nonvolatile 

Photolysis in soil 

Kow (1% Kow) 

PH 4 

PH 7 

PH 9 

MRID 46801707 

Environmental 

phototransformation 

half-life based on 

sunlight expected in 

Pheonix, AZ (33.26" N) 

1.89 (0.276) 

0.044 (-1.36) 

0.026 (-1.58) 

Product chemistry; not 

likely to bioaccumulate 

Persistence 

Aerobic soil metabolism 

Anaerobic soil 

metabolism 

Aerobic aquatic 

metabolism 

Anaerobic aquatic 

metabolism 

MRID 46801705 

MRID 46801706 

Hydrolysis 

Photolysis in water 

Stable (pH = 5,7,9) 

Stable 

MRIDs 4680 1709, 

46801710,46801711 

2 compartment, 4 

parameter exponential 

model (DFOP) 

MRID 46801712 

MRID 46801713 

MRIDs 46801714, 

46801715 

Soil Texture 

Loamy sand 

Silt loam 

Sandy loam 

Mobility 

Batch equilibrium 

Stable 

Stable 

Stable 

DT~o (dl 

5.8 

63 

23 

Soil Texture 

Silt loam 

Loamy sand 

DT~o (dl 

749 

1424 

208 

0.977 

0.998 

0,990 

~f' 

0.98 

1.2 

1/N 

0.93 

0.91 

& 

21 

100 

MRID 46801703 
I PARAMETER VALUE REFERENCE1 I COMMENTS 

Clay loam 

Sandv loam 

I ( based on low vapor 

Laboratory volatility 

0.34 

0.39 

Silt loam 

Sandy loam 

pressure 

Field Dissipation 

I I I 

Manitoba 19.2d 1531d 119 I model (DFOP) 

0.98 

0.95 

Washington 

Saskatchewan 

I Ontario 1 18d 1 178d 18.9 I 

20 

35 

3.2 

16 

Terrestrial field 

dissipation 

I Bioaccumulation 

NA 

DTS0 

8.9 d 

5.7 d 

Location 

Kansas 

North Dakota 

5.7d 

10d 

0.93 

0.83 

Volatility not likely 

a. Degradation 

213 

345 

DTgO 

45 d 

44 d 

213d 

260d 

Accumulation in fish, 

BCF 

Under aerobic conditions pyrasulfotole degraded in 3 soils (Goldsboro loamy sand, 

LaDelle silt loam, sandy loam from Germany) according to an apparent bi-phasic pattern 

with observed DTsos ranging from 4-65 d and observed DT90s ranging from >120->358 d. 

A 2-compartment, 4-parameter exponential model, also known as Double First Order in 

Parallel (DFOP), was used to fit the data and resulted in modeled DTsOs ranging from 6- 

63 d and DT90s ranging from 208-1424 d (MRIDs 46801709,406801 71 0,46801 7 1 1). 

The DFOP model was used to fit the data because it appeared to describe the data better 

than alternative models (see Appendix B for details). Degradation products included 

pyrasulfotole-benzoic acid (AE B 197555), C02 and unextractable residues. Unidentified 

extractable residues were identified at maximums of 52.6-14%. Soil samples were 

extracted using one solvent system [acetonitrile: water (2: 1, v:v) ] with an Accelerated 

Solvent Extraction (ASE) system, which conducted a two-phase ["mild" (40°C, 103 bar) 

and "aggravated" (1 OO°C, 103 bar) conditions] extraction. Unextractable residues were 

identified at maximums of 35-62% of applied radioactivity in the 3 soils. The 

unextractable residues are uncharacterized and it is uncertain whether they consist of 

degradates of risk concern. Under sterile conditions, however, the formation of 

unextractable residues (as well as the formation of COz and the benzoic acid degradate) 

were negligible. In terrestrial field dissipation studies pyrasulfotole dissipated from the 

whole soil profile with modeled (DFOP) DTgOs ranging 44-53 1 d and the amount of total 

residue (excluding unextractable residues which are not measured in these studies) carry 

% carry over 

4.7 

7.7 

11 

37 

I. Units of (mg/kg)/(mg/~)"N, where IIN is the Freundlich exponent. 

2. Approximation calculated from the Freundlich coefficient, per standard EFED guidance. 

NO data 

MRIDs 468017 16, 

46801717,46801718, 

46801719 

2 compartment, 4 

parameter exponential 

Bioaccumulation is not 

expected based on low 

log KO, 
over to the following growing season ranged from 4.7 to 37% (MRIDs 46801716, 

46801717,46801718,46801719). 

In aquatic systems, pyrasulfotole is stable to hydrolysis and photolysis (MRIDs 

46801 705,46801 706). In aerobic aquatic metabolism studies, pyrasulfotole variably 

partitioned to the sediment and formed unextractable residues but there was no evidence 

of degradation. In a pond water-sandy loam sediment (water pH 4.8, sediment pH 4.9, 

pyrasulfotole residues partitioned from the water layer to the sediment with 

water:sediment ratios of 100: 1 at day 0,2: 1 at day 55, 1 :4 at day 88 and were 1 :>lo 

thereafter. Unextractable residues were identified at a maximum of 73% at study 

termination. In a pond water-silty clay sediment (water pH 7.5, sediment pH 6.9), 

pyrasulfotole residues partitioned from the water layer to the sediment with 

water:sediment ratios of 100: 1 at day 0, 3 : 1 at days 2 1, and were 2: 1 thereafter. 

Unextractable residues were identified at maximums of 13 % at day 104 and were 1 1 % at 

study termination. The more acidic pond water-sandy loam sediment resulted in 

substantially more partitioning to the sediment and formation of unextractable residues 

than the less acidic pond water-silty clay sediment system. The pH of the more acidic 

system approaches the pKa from pyrasulfotole (pKa = 4.2). Pyrasulfotole is considered 

stable to microbial degradation in aquatic systems (MRID 46801 7 13). Under anaerobic 

conditions pyrasulfotole is also stable (MRIDs 46801 7 12,468 17 14,46801 7 15). 

b. Mobility and Transport 

Batch equilibrium studies resulted in organic carbon sorption coefficients (kc) ranging 

from 20 to 345 ml/g,, with a median value of 68 ml/aC (MRID 46801 703). There is 

some evidence the pyrasulfotle may become less mobile as it undergoes microbial 

degradation under certain conditions. In a supplementary experiment during the aerobic 

soil metabolism studies, the potential mobility of pyrasulfotole appeared to decrease with 

time from moderately mobile (LC values of 276-357) at 50 days posttreatment to slightly 

mobile (&, values of 2,090-2,183) at 358 days in the Goldsboro loamy sand (pH = 5.6) 

(MRID 46801 709). However, in the LaDelle silt loam (pH = 7.0), the potential mobility 

of pyrasulfotle appeared to remain mobile (Kc of 88) after one year posttreatment (MRID 

46801710). 

In terrestrial field dissipation studies, pyrasulfotole showed variable downward migration 

in the soil profile under bare soil conditions. In some studies, pyrasulfotle was confined 

to 0-1 5 cm whereas in others, it was detected at quantifiable levels as deep as 75-90 cm 

(MRIDs 46801716,46801717,46801718,46801719). 

Since pyrasulfotole has a Kd less than 5 in most soils and is persistent (stable to 

hydrolysis, phtolysis and only moderately susce tible to aerobic degradation in soils), is If not volatile (Henry's Law constant of 3.5 x 10- atm-m4/mol), and shows movement to 

90 cm during some field dissipation studies, there is potential for groundwater 

contamination (Cohen, 1984). 
c. Field Studies 

The soil dissipation/accumulation of pyrasulfotole under bare ground and cropped 

(wheat) conditions was studied in Kansas, North Dakota, and Washington in the United 

States (MRIDs 46801 71 6,46801 7 17,46801 71 8), and under bare ground conditions in 

Saskatchewan, Manitoba, and Ontario in Canada (MRID 46801 719). Under bare ground 

conditions, pyrasulfotole dissipated from the entire soil profile with DTSOs and DTgOs 

(DFOP) ranging from 5.7 -1 8 d and 44 - 53 1 d, respectively. Carryover of total residues 

(excluding unextractable residues which are not measured in these studies) in the soil 

column to the following growing season was 4.7 - 37 % in the various studies. 

Pyrasulfotole was not detected (above LOQ) below 15 cm at the Kansas, North Dakota 

and Ontario sites. Pyrasulfotole was detected (above LOQ) as deep as 75-90 cm at the 

Washington site and as deep as 30-45 cm at the Saskatchewan and Manitoba sites. The 

major transformation product, pyrasulfotole-benzoic acid (AE B197555), was not 

detected (above LOQ) below 15 cm at the Kansas, North Dakota and Manitoba sites. It 

was detected (above LOQ) as deep as 45-60 cm at the Washington site, and as deep as 

15-30 cm at the Saskatchewan and Ontario sites. 

d. Degradates 

There was one major degradate, pyrasulfotole-benzoic acid (2-mesyl-4- 

trifluoromethylbenzoic acid; RPA 203328; AE B197555), detected in the aerobic soil 

metabolism and terrestrial field dissipation studies. Pyrasulfotole-benzoic acid is highly 

mobile with measured kc of 0.9 - 1.5 mllg,, (MRID 4681704). Based on available 

ecological effects data (see page 37), exposure to pyrasulfotole-benzoic acid is not 

assessed because it is not of risk concern. 

Unextractable residues were identified at maximums of 35-62% of applied radioactivity 

in the aerobic soil metabolism studies. The unextractable residues are uncharacterized 

and it is uncertain whether they consist of degradates of risk concern or of parent 

pyrasulfotole. Under sterile conditions, however, the formation of unextractable residues 

(as well as the formation of C02 and the benzoic acid degradate) were negligible. 

2. Measures of Aquatic Exposure 

a. Aquatic Exposure Modeling 

Tier I1 modeling for selected scenarios representing proposed uses was used to generate 

estimated environmental concentrations (EECs). For Tier 11, two models are used in 

tandem: the Pesticide Root Zone Model, (PRZM, Carsel et al., 1997) and the Exposure 

Analysis Modeling System (EXAMS, Burns, 1997). PRZM (3.12 beta dated May 24, 

2001) simulates fate and transport on the agricultural field, and EXAMS (2.98.04, dated 

July 18,2002) simulates the fate and resulting daily concentrations in the water body. 

Simulations are carried out with the linkage program shell, PE4VOl .pl (dated August 13, 

2003), which incorporates the standard crop and orchard scenarios developed by EFED. 

Simulations are run for multiple (usually 30) years, and the EECs represent peak values 
that are expected once every ten years based on the thirty years of daily values generated 

during the simulation. Additional information on these models can be found at: 

http://www.epa.~ov/oppefed l/models/water/index.htm. 

For aquatic endpoints, the exposure is estimated for the maximum application pattern to a 

10-ha field bordering a 1 -ha pond, 2-m deep (20,000 m3) with no outlet. Exposure 

estimates generated using this standard pond are intended to represent 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 beyond 1 0-ha, it becomes increasingly unlikely 

that the entire watershed is planted with a non-major single crop that is all treated 

simultaneously with the pesticide. For major crops like cereal grains, however, this may 

not be the case. 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. 

OPP standard PRZM crop scenarios, which consist of location-specific soils, weather, 

and cropping practices, were used in the simulations to represent proposed labeled uses of 

pyrasulfotole. These scenarios were developed to represent high-end exposure sites in 

terms of vulnerability to runoff and erosion and subsequent off-site transport of pesticide. 

Pyrasulfotole is being proposed for use on wheat, barley, oats and triticale. All available 

OPP standard PRZM scenarios for wheat were modeled, ND wheat, OR wheat OP, and 

TX wheat OP. These wheat scenarios are also considered surrogates for the other cereal 

grain uses on the label (oats, barley and triticale). The Texas and Oregon scenarios were 

developed for the organophosphate (OP) cumulative drinking water assessment and as 

such were developed to be vulnerable to cumulative OP exposure and may not be 

vulnerable for single chemicals or other chemical classes on a national scale. A summary 

of the crop scenarios used to estimate pyrasulfotole concentrations in the aquatic systems 

for ecological risk assessment are listed in Table 6. 

TABLE 6. Sum1 

PYRASULFOTOLE 1 USE 

larv of Cro~ Scenarios 

CROP SCENARIO 

ND wheat: Cass County, 

Bearden silty clay loam 

OR wheat: Willamette 

Valley, 

Bashaw clay - 

TX wheat: Blacklands 

prairie, Crockett fine sandy 

loam 

STATION CHARACTERIZATION 

MLRA 2; W24232 Winter wheat, OP scenario 

MLRA 87; W13958 Winter wheat, OP scenario 
PRZMiEXAMS modeling was done using the proposed maximum label rate. Input 

parameters are listed in Table 7. Pesticide applications were simulated as aerial spray 

applications. The proposed label recommends applying pyrasulfotole between 1" leaf 

and flag leaf (approximately 7-45 days post emergence for spring wheat and 7-2 10 days 

post emergence for winter wheat). The first date of application was chosen to be one 

week post-emergence, although applications are expected anytime during the application 

window. 

Since PRZMiEXAMS require first order half-lives (rate constants), they were estimated 

by dividing the DFOP-modeled DTgO by 3.32 (the ratio between DT5() and DT90 for first 

order reactions). Modeling inputs were selected according to EFED's Input Parameter 

Guidance (USEPA 2002). An aerobic soil metabolism first order half-life of 439 d (the 

upper 90th percentile confidence bound on the mean) was used. A soil organic carbon 

partitioning coefficient (&,) of 122 ml/h,, the mean of six soils, was used. 
TABLE 7. PRZMIEXAMS Input Parameters for Aerial Application of Pyrasulfotole 

to Cereal Grains. 

I INPUT PARAMETER VALUE 

0.045 (0.05) 

SOURCE 

AE 03 17309 SE06 

lbs a.i./A (kg a.i.1ha) Herbicide (4.4%) I Applications per year AE 03 17309 SE06 Label maximum 

Herbicide (4.4%) 

Date of application 

ND Wheat 

OR Wheat 

TX Wheat 

Chemical application 

method (CAM) 

IPSCND Input 

7 days post emergence 

May 22"d 

September 8th 

October 17" 

AE 03 17309 SE06 

Herbicide (4.4%) 

Assumption 

Foliar application I 

pesticide remaining on foliage after 

harvest is converted to surface I 

I Spray drift fraction Input parameter 

I Application efficiency Input parameter 

guidance1 

Aerial spray default 

Product chemistry 

Product chemistry 

Calculated 

I Water solubility (mg/L) Product chemistry 

Organic carbon-water MRID 46801703 

partition coefficient 

Aerobic soil metabolism MRIDs 46801709, 

46801710,46801711 on the mean where tl12 is estimated by 

metabolism tIl2 (d) 

MRID 46801713 

Anaerobic aquatic 

metabolism tl12 (d) 

Hydrolysis tl12 (d) 

Photolysis tIl2 (d) 

I. EFED input parameter g 

httn:llwww.c~a.~ovlo~ncfe~ 

MRIDs 46801714, 

46801715 

MRID 46801705 

stable I 

0 

0 

 dance is located 

l lmodels/water/i~ 

stable 

MRID 46801706 

t: 

)ut guidancc2 28 O2.htn 

The EECs listed in Table 8 reflect maximum 1 -in-1 0 year surface water concentrations 

based on the proposed maximum application rates for aerial applications to wheat, barley, 

oats, and triticale (see APPENDIX C for the output data from the ND Wheat, OR Wheat, 

and TX Wheat scenarios). 
Table 8. Tier I1 Surface Water 1-in-10-Year Estimated Environmental 

The ecological pond modeled with EXAMS is a static water body of fixed volume with 

no outlet. Since pyrasulfotole is persistent in aquatic environments and since the 

ecological pond has no outlet, there was a modeled accumulation of pyrasulfotle in the 

pond throughout the 30 year simulations. Exposure endpoints, in this assessment, are 

based on yearly peak concentrations. In the case of persistent compounds, a 1-in-10 year 

EEC does not reflect varying meteorological conditions that are expected once every 10 

years, since the yearly peaks are not independent but are actually correlated to the 

previous year's peak concentration. 

b. Aquatic Exposure Monitoring and Field Data 

Concentrations (EECs) of Pyrasulfotole from Cereal Grain Use 

There were no national-scale monitoring data for pyrasulfotole available for this 

assessment. 

PRZM 

SCENARIO 

ND wheat 

OR wheat 

TX wheat 

(ppb). 

3. Measures of Terrestrial Exposure 

60-DAY 

7.7 

6.5 

9.9 

a. Terrestrial Exposure Modeling 

90-DAY 

7.6 

6.4 

9.9 

The application method for the proposed pyrasulfotole use on cereal grains is limited to 

foliar spray (ground, aerial, and sprinkler irrigation), therefore, for this terrestrial 

exposure assessment, we consider only foliar applications. The EEC values used for 

terrestrial animal exposure are derived from the Kenaga nomograph, as modified by 

Fletcher et al. (1 994), based on a large set of actual field residue data. The upper limit 

values from the nomograph represent the 95th percentile of residue values from actual 

field measurements (Hoerger and Kenaga, 1972). The Fletcher et al. (1 994) 

modifications to the Kenaga nomograph are based on measured field residues from 249 

published research papers, including information on 1 18 species of plants, 12 1 pesticides, 

and 17 chemical classes. These modifications represent the 95th percentile of the 

expanded data set. Risk quotients are based on the most sensitive LCso and NOAEC for 

birds (bobwhite quail and mallard duck) and LD50 for mammals (based on lab rat 

studies). 

21-DAY 

7.7 

6.5 

10 

APP. RATE (Ibs 

a.i./Alyr) 

0.045 

0.045 

0.045 

We derive terrestrial estimated environmental concentrations (Table 9) for pyrasulfotole 

using the maximum proposed single application rates. Terrestrial exposure estimates for 

avian and mammalian risk assessments were derived using the T-REX model (version 

1.3.1, December 22,2006). A complete description of the input parameters and output is 

PEAK 

7.7 

6.5 

10 

4-DAY 

7.7 

6.5 

10 
contained in APPENDIX D. Exposure to upland and wetland plants is estimated using 

the TerrPlant (v1.2.1) screening model. TerrPlant estimates potential exposure fiom a 

single application using default assumptions for runoff and spray drift (Table 10). See 

APPENDIX E for more information. 

TABLE 9. EECs on Potential Food Items Following Label-Specified Applications 

(0.045 Ibs a.i./Acre) of Pyrasulfotole Using the T-REX Model (ppm). 

C. Ecological Effects Characterization 

DIETARY-BASED EECS 

Short Grass 

Tall Grass 

Broadleaf Plants/Small Insects 

FruitslPodslSeedslLar~e Insects 

TABLE 10. EECs on Plants Following Label-Specified Applications (0.045 Ibs 

a.i./Acre) of Pyrasulfotole Using the TerrPlant Model (Ibs a.i./A). 

APPENDIX F lists the ecological effect studies considered for this assessment (i.e., 

studies submitted by the registrant). Citations for all of the ECOTOX references 

identified for pyrasulfotole are found in APPENDIX A. All of the studies identified by 

ECOTOX failed the ECOTOX screening, and were rejected because they were in a 

foreign language. Therefore, all of the toxicity endpoints used here are from registrantsubmitted studies. 

RATE 

0.045 lbs ai/A 

Based on the available data, pyrasulfotole is practically nontoxic to fish and fi-eshwater 

invertebrates, slightly toxic to freshwater nonvascular plants, moderately toxic to 

estuarine/marine nonvascular plants, highly toxic to estuarine/marine invertebrates, and 

very highly toxic freshwater vascular plants. Chronic exposure resulted in reduced 

growth in fish and reduced survival in freshwater aquatic invertebrates. Pyrasulfotole is 

practically nontoxic to birds and mammals on an acute oral exposure basis. Chronic 

exposure resulted in reduced male weight gain in birds and delayed maturation and 

corneal opacity in mammals. Monocots were the least sensitive group of terrestrial plants 

tested in both seedling emergence and vegetative vigor studies. See Table 11 for the 

assessment endpoints considered in this assessment. 

KENAGA VALUES 

Upper Bound 

10.8 

4.95 

6.08 

0.68 

'Loading is runoff plus drift (Ibs ai1A) 

APPLICATION 

METHOD 

Ground 

Aerial 

Mean 

3.83 

1.62 

2.03 

0.32 

ADJACENT 

UPLAND 

LOADJNG' 

0.0027 

0.0045 

ADJACENT 

WETLAND 

LOADING 

0.0230 

0.0248 

DRIFT ONLY 

0.0005 

0.0023 
TABLE 11. Summary of Specific Assessment Endpoints for Animals and Plants 

Considered in this Assessment. 

TAXA I MEASURE OF EFFECT 

Freshwater 

Invertebrates 

Survival, growth and/ I Species I Toxicity 

or reproduction of: 

Freshwater Fish 

Fish 

Endpoint 

EstuarineNarine 

Invertebrates 

Acute 

Aquatic Plants 

Oncorhychus mykiss 

Rainbow trout 

Chronic 

Pimephales promelas 

Fathead minnow 

Acute 

Daphnia magna ( ECso = >95.8 mg/~' I Mortality 

LCso = >96 mg/~' Mortality 

Chronic 

Daphnia magna ] NOAEC = 12.8 mg a.i./L I Mortality 

Acute 

Chronic 

Not Available I Not Available ( NIA 

Cyprinodon variegates 

Sheepshead minnow 

Chronic 

Not Available I Not Available I N/A 

Acute 

NOAEC = 0.58 mg a.i./L 

Americamysis buhiu 

Mysid 

Listed 

Lemna gibba I NOAEC = 9.57 pg a.i./L I Reduction in frond dry 

Reduction in total length 

LCso = >lo0 mg./~' 

Acute 

Mortality 

LC50 = 1.1 mg1L 

Lemna gibba 

Duckweed 

algae 

Mortality 

Duckweed 

EC50 = 28 pg a.i./L 

I weight 

Reduction in frond dry 

weight 

Acute 

Acute 

Skeletonemu costatum 

Marine diatom 

Listed 

Pseudokirchneriella 

subcapitata Freshwater 

algae 

Skeletonemu costaturn 

Marine diatom 

Acute 

ECso = 8.3 mg a.i./L 

Colinus virginianus 

Northern bobwhite quail 

Anus platyrhynchos 

Mallard duck 

Chronic 

Anus platyrhynchos 

Mallard duck 

ECSo = 11 mg a.i./L 

Reduction in biomass 

NOAEC = 2.53 mg a.i./L 

Reduction in cell density 

and biomass 

Reduction in biomass 

LC50 = >4,9 1 1 mg/kg-diet' 

LDsO = >2,000 mg/kg-bw' 

LCs0 = >5,089 mg/kg-diet' 

Reduction in cell density, 

growth rate, and biomass 

Listed 

Mortality 

NOAEC = 167 mg a.i./kgdiet 

Pseudokirchneriellu 

subcapitata Freshwater 

Decreased male body 

weight gain 

NOAEC = 2.6 mg a.i./L 
TAXA 

Survival, growth and/ 

or reproduction of: 

Mammals 

Terrestrial 

Invertebrates 

Terrestrial Plants 

This endpoint used to 

MEASURE OF EFFECT 

Species Toxicity Endpoint 

Acute 

Wistar rat LDso = >2,000 mg a.i.lkg- Mortality 

bw' 

Chronic 

Wistar rat NOAEL = 2.5 mg a.i.1kg- Delayed balano-preputial 

bw separation (an indicator of 

the onset of puberty) in FI 

pups and diffuse and 

reticulate corneal opacity 

in both generations 

Acute 

Apis mellifera LDsO = >75 pgibee Mortality 

Honey Bee (contact)' 

Acute (Seedling Emergence) 

Monocot: NIA I EC25 = >0.0249 lb ailacre ( NIA 

Dicot: Tomato I EC25 = 0.001 1 lb a.i.1A I Decreased dry weight 

Listed (Seedling Emergence) 

Monocot: NIA I NOAEC = 0.0249 lb I NIA 

a.i./acre 

Dicot: Tomato NOAEC = 0.000399 lb Decreased dry weight 

a.i.1A 

Dicot: Tomato 1 EC2S = 0.00081 lb a.i.1A I Decreased dry weight - - 

Listed (Vegetative vigor) 

Monocot: Onion I NOAEC = 0.0125 lbs a.i.1A I Decreased dry weight 

Dicot: Tomato I EC05 = 0.000797 Ib a.i.1A ( Decreased dry weight 

lculate RQs in the 'Risk Description' section of this assessment. 
1. Aquatic Effects Characterization 

a. Aquatic Animals 

Studies were submitted for three freshwater fish [rainbow trout (Oncorhychus mykiss), 

bluegill sunfish (Lepmis macrochirus), and fathead minnow (Pimephales promelas)], one 

freshwater invertebrate (Daphnia magna), one estuarinelrnarine fish [sheepshead minnow 

(Cyprinodon variegates)], one estuarinelrnarine mollusk [Eastern oyster (Crassostrea 

virginica)], and one estuarinelmarine crustacean [mysid shrimp (Americamysis bahia)], 

all exposed to technical grade pyrasulfotole. 

Acute toxicity tests for Daphnia (MRID: 46801 7-21), sheepshead minnow (MRID: 

468017-26), mollusk (MRID: 46801 7-22), rainbow trout (MRID: 468017-24) and 

bluegill sunfish (MRID: 46801 7-25) all resulted in no effects, including sublethal effects, 

to the species at the highest treatment level tested. The mysid study (MRID: 46801 7-23) 

resulted in an ECso of 1.1 mg a.i./L. At the 24-hour observation interval, lethargy was 

observed in the mean-measured 1.5,2.9 and 6.2 mg ailL treatment levels and erratic 

swimming was observed in the mean-measured 6.2 and 12 mg ai/L treatment levels. At 

the 48-hour observation interval, one mysid in the mean-measured 1.5 mg ai/L treatment 

level was lethargic and on the bottom of the test vessel, several mysids were lethargic in 

the mean-measured 6.2 mg ai/L treatment level and all surviving mysids in the meanmeasured 12 mg ai1L treatment level were swimming erratically. At 72- and 96-hours, no 

sub-lethal effects were observed in the control or any of the treatment levels. Therefore, 

for acute effects, the following endpoints will be used to assess the risk of pyrasulfotole 

to aquatic animals: freshwater fish - LCso = >96 mg a.i./L; freshwater invertebrate - 

EC50 = >95.8 mg a.i.1L; estuarinelmarine fish - LC50 = >I00 mg a.i./L; and 

estuarinelrnarine invertebrate - ECso = 1.1 mg a.i./L. 

A chronic test for Daphnia resulted in a 21-day NOAEC of 12.8 mg a.i./L (MRID: 

46801 7-27), based on reduced survivallimmobility (and other clinical signs of toxicity). 

A freshwater fish early life-stagelreproductive study on fathead minnow resulted in a 

NOAEC of 0.58 mg a.i.1L (MRID: 468017-27). The most sensitive endpoint for this 35- 

day test was a reduction in total length. Therefore, for chronic effects, a NOAEC of 12.8 

mg a.i./L and a NOAEC of 0.58 mg a.i./L will be used to assess the risk of pyrasulfotole 

to freshwater invertebrates and freshwater fish, respectively. 

Based on these submitted studies, pyrasulfotole is classified as practically nontoxic to 

fish and freshwater invertebrates but is highly toxic to estuarinelmarine invertebrates on 

an acute exposure basis. There were no mortality or sublethal effects at the highest 

treatment levels tested in most of the acute studies (i.e., all of the LC50 or ECSO endpoints 

are 'greater than' values except for the EC50 value for the mysid). These 'greater than' 

endpoints were not used to calculate RQ values here; however, they are used to help 

characterize the risk in the 'Risk Description' section of this assessment. 
b. Aquatic Plants 

Studies were submitted for a freshwater vascular plant [duckweed (Lemna gibba)], bluegreen algae (AnabaenaJlos-aquae), a freshwater diatom (Navicula pelliculosa), a green 

algae (Pseudokirchneriella subcapitata formerly known as Selenastrum capricornutum), 

and a marine alga (Skeletonema costatum) exposed to technical grade pyrasulfotole. 

Pyrasulfotole is very highly toxic to duckweed based on reductions in frond dry weight in 

a 7-day toxicity study (MRID: 46801 7-36). In this study an ECso value of 28 pg a.i./L 

was reported; the associated NOAEC was 9.57 pg a.i./L. Therefore, an ECS0 value of 28 

pg a.i./L and a NOAEC of 9.57 pg a.i./L will be used to assess the risk of pyrasulfotole to 

aquatic macrophytes. 

Acute toxicity tests in freshwater nonvascular plants resulted in 96-hour EC50 values 

ranging from 11 mg a.i./L for reductions in cell density and biomass in green algae 

(MRID: 46801 7-37) to 53 mg a.i./L based on reductions in biomass in freshwater diatoms 

(MRID: 468017-38). The lowest EC50 value of 11 mg a.i./L based on decreased cell 

density and biomass and the associated NOAEC of 2.6 mg a.i./L for reductions in cell 

density, growth rate, and biomass in Pseudokirchneriella subcapitata will be used to 

assess the risk of pyrasulfotole to freshwater nonvascular plants. 

An acute (96-hour) toxicity test with a marine diatom resulted in an ECso value of 8.3 mg 

a.i./L based on a reduction in biomass in Skeletonema costatum (MRID: 468017-40). 

The ECso value of 8.3 mg a.i./L and the associated NOAEC of 2.53 mg a.i./L for 

reductions in biomass in Skeletonema costatum will be used to help assess the risk of 

pyrasulfotole to marine plants. 

Based on the data, pyrasulfotole is classified as very highly toxic to vascular aquatic 

plants, slightly toxic to freshwater nonvascular plants, and moderately toxic to marine 

plants on an acute exposure basis. 

2. Terrestrial Effects Characterization 

a. Terrestrial Animals 

Birds 

Based on the LD50 value for the northern bobwhite quail (Colinus virginianus) of >2,000 

mglkg-bw, pyrasulfotole is characterized as "practically nontoxic" to avian species on an 

acute oral-exposure basis (MRID: 46801 7-29). Pyrasulfotole is "practically nontoxic" to 

"slightly toxic" to avian species on a subacute dietary-exposure basis, with the lowest 

of >4,911 mglkg-diet reported for northern bobwhite quail (MRID: 46801 7-30). 

The LCs0 for the mallard duck (Anas platyrhychos) is >5,089 mg a.i./kg diet (MRID: 

46017-31). In this assessment, an value of >4,911 mglkg-diet and an LDSo of 

>2,000 mgkg-bw will be used to assess the risk of pyrasulfotole to birds. In all of the 

avian acute toxicity studies submitted, there were no mortality or sublethal effects at the 
highest treatment levels tested (i.e., all of the LDS0 and LCso endpoints are 'greater than' 

values), therefore, these endpoints are not used to calculate RQ values here. They are, 

however, used to help characterize risk in the 'Risk Description' section of this 

assessment. 

Avian reproduction studies were performed for pyrasulfotole in two species, mallard 

duck and northern bobwhite quail. The lowest LOAEC was for the mallard duck (557 

mg/kg-diet) based on decreased male body weight gain at the highest treatment level 

(MRID: 46801 7-33). The lowest NOAEC was also for the mallard duck (1 67 mg a.i./kg 

diet) (MRID: 468017-33). In the northern bobwhite quail study there were slight, but 

statistically significant, reductions (3 - 9%) in ratios of eggs set to eggs laid, number 

hatched to eggs laid, number hatched to live 3-week embryos, and hatchling weights at 

the highest treatment level which resulted in a LOAEC and NOAEC of 594 mg a.i./kg 

diet and 205 mg a.i./kg diet, respectively. For the purposes of this risk assessment, 167 

mgkg-diet serves as the toxicological endpoint for evaluating chronic effects in birds. 

Mammals 

Based on the LDS0 value for the Wistar rat of >2,000 mgtkg-bw, pyrasulfotole is 

characterized as "practically nontoxic" to mammalian species on an acute oral-exposure 

basis (MRID: 46801 836). In the acute oral study, involving a single doselanimal and a 

14-day observation period, there were no mortalities at any of the treatment levels. 

Additionally, there were no indications of neurotoxic effects or effects on body weight 

gain or food consumption at any treatment level. There were, however, increased 

incidents of corneal opacity and corneal neovascularization in females and retinal 

degeneration in males at the 500 mglkg-bw treatment level. The corneal effects are 

believed to be the result of increased tyrosinemia from HPPDase inhibition (the 

biochemical mechanism of action of pyrasulfotole). Because there were no mortalities at 

the highest treatment levels tested (i.e., the LDso endpoint is a 'greater than' value), this 

endpoint (>2,000 mgkg-bw ) is not used to calculate RQ values here. It is, however, 

used to help characterize risk in the 'Risk Description' section of this assessment. 

In a two generation reproductive toxicity study with the Wistar rat (MRID: 46801 907), 

the reproductive NOAEL was 2.5 mg/kg bwlday based on delays of balano-preputial 

separation (an indicator of the onset of puberty) in Fl males at the LOAEL of 26.3 mg/kg 

bwlday. In a neurotoxicity study in the Wistar rat (MRID: 4680 19 17), the NOAEL was 

3.8 mglkg-bwlday based on ocular opacities in dams at 237 mg/kg-bwlday; and 

decreased postnatal weights, delayed preputial separation, decreased brain weights and 

retinal degeneration in offspring at the highest treatment levels (237 mglkg-bwlday). For 

the purposes of this risk assessment, a NOAEL of 2.5 mg/kg-bwlday serves as the 

toxicological endpoint for evaluating chronic effects in mammals. 

Terrestrial Invertebrates 

The registrant submitted one guideline (acute honey bee-contact) and two non-guideline 

(acute honey bee-oral and acute earthworm) terrestrial invertebrate toxicity studies for 
pyrasulfotole. These studies resulted in the following: a honey bee oral LDso of >I20 pg 

a.i./bee (MRID: 468017-34); a honey bee contact LD50 of >75 pg a.i./bee (MRID: 

468017-35); and an EC50 and NOAEC of >1,000 mg a.i./kg for earthworms (MRID: 

4680 17-4 1). Therefore, pyrasulfotole is classified as 'practically nontoxic' to non-target 

terrestrial insects on an acute oral and contact exposure basis. In all of the terrestrial 

invertebrate studies there was no mortality or sublethal effects at the highest treatment 

levels tested (i.e., all of the LD5~ and ECso endpoints are 'greater than' values). 

b. Terrestrial Plants 

The effects of the proposed North American pyrasulfotole formulations, AE 03 17309 + 

Bromo Herbicide (3.3% pyrasulfotole, 13.4% bromoxynil octanoate, and 12.9% 

bromoxynil heptanoate) and AE 03 17309 SE06 Herbicide (4.4% pyrasulfotole), were 

tested on various monocots and dicots in Tier I1 seedling emergence and vegetative vigor 

studies. 

Results of the Tier I1 seedling emergence studies with the AE 03 17309 02 SE06 and AE 

03 17309 + Bromo formulations showed no measurable effects to monocots at any of the 

tested treatment levels [the highest treatment levels for monocots were 0.0249 to 0.0994 

Ibs a.i./acre - depending on the species - for the AE 03 17309 02 SE06 formulation, and 

0.029 Ibs a.i.(pyrasulfotole only)/acre for the AE 03 17309 + Bromo formulation]. For 

dicots, tomato was the most sensitive species in the seedling emergence studies for both 

formulations, with decreased dry weight as the most sensitive endpoint affected. The 

NOAEC and EC2S values were 0.000399 Ib a.i./A and 0.001 1 lb a.i./A, respectively, for 

tomato dry weight in the study with the AE 03 17309 02 SE06 formulation. In the 

seedling emergence study with the AE 03 17309 + Bromo formulation, the NOAEC and 

EC2s were 0.00022 lb a.i.(pyrasulfotole only)/A and 0.00025 lb a.i. (pyrasilfotole 

only)/A, respectively. Although the AE 03 17309 + Bromo formulation is more toxic to 

dicots than the AE 03 17309 02 SE06 formulation based on the seedling emergence 

studies, the results fiom the SE06 formulation are used to calculate RQs since the AE 

03 17309 + Bromo formulation includes other active ingredients. Because AE 03 17309 + 

Bromo formulation is a mixture of different active ingredients, the results from the 

studies using this formulation cannot be used to specifically assess the risks of 

pyrasulfotole to plants. Results fiom the AE 03 17309 + Bromo formulation, however, 

are incorporated into the Risk Description section of this assessment. Therefore, a 

NOAEC of 0.00039 lb a.i./A and an ECZ5 of 0.001 1 lb a.i./A are used to assess the effects 

of exposure to pyrasulfotole on seedling emergence in non-listed and listed terrestrial 

plants (see Table 12). 

Results of the Tier I1 vegetative vigor studies identify onion as the most sensitive 

monocot with decreased dry weight as the most sensitive endpoint affected (with the AE 

03 17309 02 SE06 formulation). The NOAEC and EC2S values for onion dry weight were 

0.0125 Ibs a.i./A and 0.017 lbs a.i./A, respectively. No effects were seen in monocots in 

the vegetative vigor study with the AE 03 17309 + Bromo formulation [the highest 

treatment level tested was 0.030 lbs a.i. (pyrasulfotole only)/acre]. For dicots, tomato 

was the most sensitive species with the AE 03 17309 02 SE06 formulation (NOAEC = 
0.000797 lb a.i./A; EC25 = 0.00081 lb a.i./A for dry weight), while cucumber was the 

most sensitive dicot with the AE 03 17309 + Bromo formulation [NOAEC <0.00012 Ib 

a.i. (pyrasulfotole only)/A; EC25 = 0.00017 lb a.i. (pyrasulfotole only)/A for dry weight]. 

Therefore, a NOAEC of 0.0125 lbs a.i./A and an EC25 of 0.017 lbs a.i./A, for onion dry 

weight, are used to assess the effects of exposure to pyrasulfotole on vegetative vigor in 

monocot plants. 

For dicots, although the AE 03 17309 + Bromo formulation is more toxic than the AE 

03 17309 02 SE06 formulation based on the vegetative vigor studies, the results from the 

SE06 formulation are used to calculate RQs since the AE 03 17309 + Bromo formulation 

includes other active ingredients. Results from the AE 03 17309 + Bromo formulation are 

incorporated into the Risk Description section of this assessment. Therefore, a NOAEC 

of 0.0.000797 lb a.i./A and an ECz5 of 0.00081 lb a.i./A (based on tomato dry weight) are 

used to assess the effects of exposure to pyrasulfotole on vegetative vigor in non-listed 

and listed terrestrial dicots (see Table 12). 

TABLE 12. Terrestrial Monocot and Dicot Endpoints (Ibs a.i./acre) from the 

Pyrasulfotole Seedling Emergence and Vegetative Vigor Studies. 

SEEDLING EMERGENCE I VEGETATIVE VIGOR 

AE 0317309 02 1 AE 0317309 + I AE 0317309 02 1 AE 0317309 + 

SE06 Formulation 

(Max. Application 

Rate = 0.045 Ib 

a.i./acre) 

only)/acre] 

ECts 1 Monocots I > 0.0249" I > 0.029 

* The most sensitive endpoint I These represent the highest concentrations tested. 

The NOAEC for the most sensitive species is below the lowest tested concentrations (<0.00012 lbs 

a.i./A), therefore, this number is the ECoS value. 

Bolded nimbers are used to calculate RQs in this assessment. 

Bromo Formulation 

[Max. Application 

Rate = 0.037 Ib a.i. 

(pyrasulfotole 

NOAEC 

3. Toxicity of the Degradate Pyrasulfotole-Benzoic Acid 

0.017" 

One major degradate, pyrasulfotole-benzoic acid (RPA 203328, AE 197555), was 

detected in the aerobic soil metabolism and terrestrial field dissipation studies. The 

toxicity data for RPA 203328 indicate that this degradate is less toxic (or at least not 

more toxic, in the case of limit tests) to fish, aquatic invertebrates, aquatic vascular 

plants, birds, earthworms, and terrestrial plants, and is equitoxic to freshwater algae when 

compared to the parent chemical on an acute exposure basis (see Table 13). No 

comparative chronic toxicity data are available for any taxa. There are no data to indicate 

that RPA 203328 is of toxicological concern (which is in agreement with HED), and, 

therefore, it will not be included in this assessment. 

SE06 Formulation 

(Max. Application 

Rate = 0.045 lb 

ailacre) 

only)/acre] 

> 0.030 

Dicots 

Monocots 

Dicots 

Bromo Formulation 

[Max. Application 

Rate = 0.037 lb a.i. 

(pyrasulfotole 

0.0011 

0.0249"' ' 

0.000399 

0.00025* 

0.029 

0.00022* 

0.00081 

0.0125" 

0.000797 

0.00017* 

0.030' 

0.000016*3L 
TABLE 13. RPA 203328 Acute Toxicity Data for aVariety of Animals and Plants. 

SPECIES I ENDPOINT I DURATION ( MRID I CLASSIFICATION I COMMENTS I 

I 

Animals 

virginianus 

Earthworms 

Eisenia 

foetida 

Earthworms 

Eisenia 

, foetida 

Freshwater 

green algae 

Selenastrum 

Rainbow trout 

Oncorhynchus 

mykiss 

Mysid 

Mysidopsis 

bahia 

Daphnid 

Daphnia 

magna 

Northern 

bobwhite 

quail 

capricornutum 

Duckweed 

IV. Risk Characterization 

ECso = > 1000 

mg a.i.1kg 

ECS0 = >I000 

mg a.i.1kg 

ECS0 = 5.9 

ppm a.i. 

NOAEC = 2.4 

Lemna gibba 

Various 

species; 

Vegetative 

Vigor 

Various 

species; 

Seedling 

Emergence 

A. Risk Estimation - Integration of Exposure and Effects Data 

Olinus I I I I I 

LC5,, = 160 

ppm a.i. 

= 145 

ppm a.i. 

EC5,, = >I 50 

mg a.i./L 

LCSo> 5265 

ppm a.i. 

ppm a.i. 

ECSo = > 9.8 

Toxicity data and exposure estimates are used to evaluate the potential for adverse 

ecological effects on non-target species. For this screening-level assessment of 

pyrasulfotole, the deterministic risk quotient method is used to provide a metric of 

potential risks. The RQ is a comparison of exposure estimates to toxicity endpoints; 

estimated exposure concentrations are divided by acute and chronic toxicity values. The 

14 days 

56 days 

120 hrs 

ppm a.i. 

Monocot: NIA 

Dicot: NIA 

Monocot: NIA 

Dicot: NIA 

96 hrs 

96 hrs 

48 hrs 

8 days 

14 days 

4680 17-42 

468017-43 

Plants 

439048-26 

14 days 

14 days 

439048-25 

447 188-01 

435732-4 1 

446935-0 1 

443999-10 

Supplemental 

Supplemental 

Acceptable 

443999-06 

443999-07 

Acceptable 

Acceptable 

Acceptable 

Acceptable 

Non-guideline; 

NOAEC = 556 

mg a.i.1kg 

Non-guideline; 

NOAEC = 2 

1000 mg 

a.i.lkg 

NOAEC = 2.4 

ppm a.i. 

Acceptable 

Flow-through; 

NOAEC = 130 

Static; 

NOAEC = 25 

ppm a.i. 

Flow-through 

test; NOAEC = 

150 mg a.i.1L 

NOAEC = 

5265 ppm a.i. 

NOAEC = 9.8 

Acceptable 

Acceptable 

ppm a.i. 

Limit test - 

NOAEC 0.13 

lbs a.i.1acre 

(highest level 

tested) 

Limit test - 

NOAEC 0.14 

Ibs a.i./acre 

(highest level 
resulting unitless RQs are compared to the Agency's levels of concern (LOCs) (see 

Table 14), which are the Agency's interpretive policy such that when LOCs are 

exceeded, the need for regulatory action may be considered. These criteria are used to 

indicate when the use of a pesticide, as directed on the label, has the potential to cause 

adverse effects on non-target organisms. 
TABLE 14. Agency Levels of Concern (LOC). 

I I I 1 

Risk - - 

Acute 

Acute Restricted 

Use 

Acute Listed 

Species 

Chronic 

Description 

Potential for acute risk to non-target organisms 

which may warrant regulatory action in addition 

to restricted use classification 

Potential for acute risk to non-target organisms, 

but may be mitigated through restricted use 

classification 

RQ 

acute RQ > 0.5 

Listed species may be potentially affected by 

use 

Non-Listed and 

Listed Plant 

Taxa 

aquatic animals, 

mammals, birds 

acute RQ > 0.1 

acute RQ > 0.2 

Potential for chronic risk may warrant 

regulatory action, listed species may potentially 

be affected through chronic exposure 

aquatic animals 

mammals and 

birds 

I 

acute RQ > 0.05 

acute RQ > 0.1 

1. Non-target Aquatic Animals and Plants 

aquatic animals 

mammals and 

birds 

chronic RQ > 1 

Potential for effects in non-listed and listed 

plants 

Table 15 lists the RQs calculated for aquatic animals for exposure to pyrasulfotole, based 

on the EECs from PRZM modeling scenarios. Pyrasulfotole is classified as 'practically 

nontoxic' to fish and freshwater invertebrates on an acute exposure basis. The only acute 

RQ we calculated for aquatic animals was for estuarinelrnarine invertebrates, since all 

other aquatic animals showed no effects as the highest treatment levels tested. 

Pyrasulfotole is classified as 'highly toxic' to estuarinelrnarine invertebrates, however, 

the acute RQs for estuarinelmarine invertebrates range from 0.006 (for the OR Wheat 

scenario) to 0.009 (for the TX Wheat scenario). Therefore, no RQs for aquatic animals 

exceed the Agency's LOC for acute risk. 

all animals 

The highest calculated chronic exposure RQ for aquatic animals is 0.017 (rainbow trout), 

and is below the Agency's LOC for chronic exposure to animals. However, there are no 

chronic toxicity data available for estuarinelmarine invertebrates, which are the most 

sensitive of all of the aquatic animals tested. Estuarinelmarine invertebrates (ECSo = 1.1 

mg a.i.1L) are more than 87 times (95.811 .l) more sensitive to pyrasulfotole on an acute 

exposure basis than freshwater invertebrates (EC50 >95.8 mg a.i./L). Using an acute to 

chronic ratio and comparing the daphnid and mysid data results in a NOAEC for mysids 

of < 0.147 mg a.i./L [(95.8112.8) = 7.8; 1.117.8 = 0.1471. To trigger the Agency's chronic 

LOC, however, the estuarinelrnarine invertebrate NOAEC would need to be at least 9.9 

pg a.i./L (using the 21-day peak value from the TX Wheat scenario and an LOC of 1). In 

other words, estuarinelrnarine invertebrates would need to be at least 1,293 times more 

sensitive to pyrasulfotole than freshwater invertebrates [NOAEC - 12.8 mg a.i.1L; (12.8 

mg a.i.lL)1(0.0099 mg a.i./L) = 1,2931 on a chronic exposure basis to exceed the 

Agency's chronic LOC for listed and non-listed species. 

RQ> 1 all plants 
TABLE 15. Aquatic Animal RQ Values for Exposure to Pyrasulfotole. 

Pyrasulfotole is classified as 'slightly toxic' to freshwater algae, 'moderately toxic' to 

marine diatoms, and 'very highly toxic' to aquatic vascular plants on an acute exposure 

basis. The Agency's LOC for listed plants is exceeded for aquatic vascular plants (RQ = 

1.045) with the TX Wheat scenario. All other aquatic plant RQs are below the Agency's 

level of concern (Table 16). 

TAXA 

EstuarineiMarine Invertebrates 

Freshwater Fish 

Freshwater Invertebrates 

2. Non-target Terrestrial Animals 

EXPoSURE 

Acute 

Chronic 

Chronic 

TABLE 16. Aquatic Plant RQ Values for Exposure to Pyrasulfotole. 

Birds 

CALCULATED R 

ND Wheat ! OR Wheat TXWbeat 1 

Pyrasulfotole is classified as 'practically nontoxic' to birds on an acute and sub-acute 

exposure basis. The RQs calculated for chronic exposure range from 0 to 0.06 using 

upper 90'" percentile Kenaga values (see Table 17). Therefore, none of the avian RQs 

calculated for chronic exposure exceed the Agency LOC. 

0.007 

0.013 

< 0.001 

TAXA 

Bolded numbers indicate RQs that exceed the Agency's LOC for aquatic plants 

CALCULATED RQ 

Aquatic vascular 

plants 

Freshwater algae 

Marine diatom 

Mammals 

0.006 

0.01 1 

< 0.001 

ND wheat 

0.275 

0.805 

< 0.001 

0.003 

< 0.001 

0.003 

Non-Listed 

Listed 

Non-Listed 

Listed 

Non-Listed 

Listed 

TABLE 17. Avian RQ Values for Chronic Exposure to Pyrasulfotole. 

Pyrasulfotole is classified as 'practically nontoxic' to mammals on an acute oral exposure 

basis. The RQs calculated for chronic exposure range from 0.01 to 0.22 for dietary 

0.009 

0.017 

< 0.001 

DIETARY CATEGORY 

Short Grass 

Tall Grass 

Broadleaf PlantslSmall Insects 

Fruits/Pods/Seeds/Large Insects 

OR wheat 

0.232 

0.679 

< 0.001 

0.003 

< 0.001 

0.002 

RQ 

Upper 90th Percentile Kenaga 

0.06 

0.03 

0.04 

0.00 

TX wheat 

0.357 

1.045 

< 0.001 

0.004 

0.001 

0.004 
exposure and 0.01 to 1.87 for dose-based RQs using upper 9oth percentile Kenaga values 

(see Table 18). The RQs for three body-sizeldietary categories exceed the Agency's 

LOC for chronic exposure: 15 g and 35 g mammals that eat short grass (RQs = 1.87 and 

1.6, respectively) and 15 g mammals that eat broadleaf plants/small insects (RQ = 1.05). 

TABLE 18. Mammalian RQ Values for Chronic Exposure to Pyrasulfotole. 

Upper 90th Percentile Kenaga 

DIETARY CATEGORY 

Short Grass 

Tall Grass 

Broadleaf PlantsISmaU 

Insects 

Fruits/Pods/Seeds/Large 

Insects 

Terrestrial Invertebrates 

BODY SIZE 

15 g 

35 g 

1,000 g 

15 g 

35 g 

1,000 p 

15 g 

Granivore 

Pyrasulfotole is classified as 'practically nontoxic' to non-target terrestrial insects on an 

acute exposure basis. Potential risk to terrestrial invertebrates from chronic exposure to 

pyrasulfotole could not be assessed due to a lack of data. Screening-level risk 

assessments do not typically evaluate risks to terrestrial invertebrates; however, toxicity 

information for beneficial insects is used to develop precautionary label language where 

necessary. Based on the available data, precautionary label language for bees does not 

appear necessary. 

35 g 

1,000 g 

15 g 

35 g 

3. Non-target Terrestrial and Semi-aquatic Plants 

DIETARY-BASED RQ 

0.22 

0.10 

0.12 

Bolded numbers indicate RQs that exceed the Agency's chronic risk LOC for mammals 

1,000 g 

15 g 

35 g 

1,000 g 

Table 19 lists the terrestrial and semi-aquatic plant RQs for the maximum proposed 

application rate for pyrasulfotole based on results from the TerrPlant v. 1.2.1. Based on 

this analysis, none of the RQs for monocots, which range from 0.04 to 0.99, exceed the 

Agency's LOC of >l for plants. The RQs for semi-aquatic monocots for aerial and 

ground applications did approach the Agency's LOC for listed plants, and, therefore, the 

potential for risks to this taxon will be explored hrther in the 'Risk Description' section. 

DOSE-BASED RQ 

1.87 

1.60 

0.86 

0.86 

0.73 

0.39 

1.05 

0.01 

All of the RQs for listed and nonlisted terrestrial and wetland dicots in areas adjacent to 

pyrasulfotole use sites do exceed the Agency's LOC. Additionally, the LOC is exceeded 

- 0.9 

0.48 

0.12 

0.10 

NIA 

0.05 

0.03 

0.02 

0.01 
for listed dicots based on drift alone for aerial applications. The RQs for nonlisted dicots 

based on ground applications range fkom 0.01 (drift only) to 20.86 (adjacent wetland), 

while those for aerial applications range from 0.06 (drift only) to 22.5 (adjacent wetland). 

For listed dicots, the RQs range from 0.56 (drift only) to 57.52 (adjacent wetland) for 

ground applications and 2.82 (drift only) to 62.03 (adjacent wetland) for aerial 

applications. 

no EC25 value; could be determined fir monocots in the pyrasulfotole seedling emergence studies, only the 

results for the listed monocots are presented here. 

Bolded numbers indicate RQs that exceed the Agency's LOC for plants. ' Although this is below the Agency LOC of 1, it is close enough that we will consider it further. 

TABLE 19. RQ Values for Terrestrial and Semi-Aquatic Plants Exposed to 

Pyrasulfotole. 

B. Risk Description 

TAXA 

Nonlisted 

Species - 

Listed 

Species 

The results of this screening-level risk assessment indicate that the proposed uses of 

pyrasulfotole have the potential for direct adverse effects for listed freshwater vascular 

plants, listed and non-listed terrestrial and semi-aquatic dicotyledonous plants, and listed 

and non-listed mammals (chronic exposure). Therefore, the hypothesis from p. 14 [ . . . the 

proposed agricultural uses ofpyrasulfotole have the potential to reduce survival, 

reproduction, and/or growth in terrestrial and aquatic animals and plants through spray 

drip and/or runoff] is supported. These results are based on a modeled spray application 

rate of 0.045 lbs a.i./A per year, which represents the proposed maximum application rate 

for cereal grains. Although direct adverse effects to non-mammalian animals (aquatic 

and terrestrial) from pyrasulfotole use are not expected, given the potential for effects on 

terrestrial and aquatic plant species and mammals, indirect effects to all animals are 

possible. Since plants are vital components of most habitats and ecosystems, alterations 

in the abundance of plants or in the composition of plant communities could result in 

adverse effects to non-plant species. Potential effects include, but are not limited to, 

reduction in food resources, decrease in cover (e.g., for predator avoidance), change in 

water parameters (e.g., increases or decreases in temperature and pH), and loss of 

breedingnesting habitat. 

Reducing the proposed application rate from 0.045 lb a.i./acre to 0.040 lb a.i./acre results 

in an RQ of <l for listed aquatic vascular plants, and reducing the application rate to 

0.023 lb a.i./acre results in chronic RQs of <l for all mammalian sizeldietary categories. 

Therefore, RQs for listed aquatic vascular plants and listed and non-listed mammals 

(from chronic exposure) could be reduced to below Agency LOCs if the maximum 

proposed application rate for pyrasulfotole was reduced to 0.04 lb a.i./acre and 0.023 lb 

Both the 'Adjacent Upland' and 'Adjacent Wetland' values are based on seedling emergence data; since 

APPLICATION 

METHOD 

Ground 

Aerial 

Ground 

Aerial 

ADJACENT 

UPLAND' 

Monocot 

NIA 

NI A 

0.108 

0.18 

Dicot 

2.45' 

4.09 

6.77 

11.28 

ADJACENT 

WETLAND' 

DRIFT ONLY 

Monocot 

NIA 

NIA 

0.92.~ 

0.99" 

Monocot 

0.03 

0.13 

0.04 

0.18 

Dicot 

20.86 

22.5 

57.52 

62.03 

Dicot 

0.01 

0.06 

0.56 

2.82 
ailacre, respectively. Agency LOCs for listed and non-listed terrestrial and semi-aquatic 

dicotyledonous plants, however, are still exceeded at an application rate of 0.023 lb 

a.i./acre, indicating potential risks to dicots even at this rate. 

1. Risks to Aquatic Organisms 

a. Animals 

No aquatic animal acute or chronic risk LOCs are exceeded for any of the proposed uses 

of pyrasulfotole. The acute RQs for aquatic animals for estuarinelrnarine invertebrates 

ranged from 0.006 to 0.009, depending on the scenario modeled. The calculated RQ 

values for chronic exposure to pyrasulfotole ranged from <0.001 to 0.01 7 for all modeled 

use scenarios. 

Because there was no mortality or sublethal effects at the highest treatment levels tested 

in most of the acute aquatic animal studies submitted (with the exception of 

estuarinelmarine invertebrates), RQ values for acute exposure were not calculated for 

most aquatic animals in the Risk Characterization section of this assessment. In order to 

gain a better understanding of how the EECs for the maximum proposed pyrasulfotole 

application rate relate to the toxicity data currently available for fish and aquatic 

invertebrates, RQ calculations were made using the highest level tested as the endpoint 

value, as a conservative assumption [i.e., LC50 = 100 mg a.i./L (the actual highest 

concentrations tested in the aquatic animal studies ranged from 95.8 mg a.i./L to 104 mg 

a.i./L)]. In this exercise all of the acute RQs calculated were less than 0.001 for all 

aquatic animals. The actual RQs would likely be much lower than these since no effects 

were actually identified at the 100 mg a.i./L. Therefore, direct risk to aquatic animals 

from acute exposure to pyrasulfotole is unlikely. 

None of the aquatic animal RQs for chronic exposure exceeded the Agency's LOC. 

Chronic toxicity data, however, are not available for the most acutely sensitive aquatic 

animal taxon (i.e., estuarinelmarine invertebrate). Even though pyrasulfotole is very 

soluble and moderately mobile to mobile based on the results of batch equilibrium 

studies, in aquatic systems (based on laboratory data) it does variably partition to the 

sediment and form unextractable residues and persist as parent. Additionally, there is 

some evidence that pyrasulfotle may become less mobile as it it is exposed to viable 

microbs under certain conditions. Since PRZMIEXAMS modeling requires one input for 

soil-water partitioning coefficient that is constant throughout the simulation (Kc = 122 

ml/hc for pyrasulfotole), the modeled partitioning to the sediment may be underestimated 

relative to the aerobic aquatic metabolism studies. Therefore, there is the potential for 

pyrasulfotole to accumulate in the benthos under certain conditions and to be a risk to 

benthic and epibenthic organisms (including some estuarinelmarine invertebrates). 

Although the chronic toxicity of pyrasulfotole to estuarinelmarine invertebrates is 

uncertain, given that: (1) the potential use sites for the proposed uses largely fall outside 

of estuarine/marine environments, with the possible exceptions of California and the midAtlantic states (see Figs. 2,3, and 4); (2) the aquatic EECs used in this assessment are 

based on a static water-body with no outlet, and, thus, are likely higher than 
concentrations expected in estuarinelmarine environments; and (3) estuarinelmarine 

invertebrates would need to be 1,293 times more sensitive to pyrasulfotole than 

freshwater invertebrates on a chronic-exposure basis to exceed the Agency's chronic risk 

LOC, risks to estuarinelmarine invertebrates from chronic exposure to pyrasulfotole are 

not expected. 

Therefore, the likelihood of adverse effects on aquatic animals due to acute or chronic 

exposure to pyrasulfotole is considered low for the proposed uses based on the available 

toxicity data. Given the potential for effects on terrestrial and aquatic vascular plant 

species associated with the use of pyrasulfotole, however, indirect effects on aquatic 

animals are possible. 

b. Plants 

Based on the predicted EECs for the modeled pyrasulfotole use and available toxicity 

data, the LOC for listed species is exceeded for vascular aquatic plants using the TX 

Wheat scenario (RQ = 1.045). This indicates the potential for direct effects to listed 

aquatic vascular plants and indirect effects to listed species that rely on aquatic vascular 

plants for at least some part of their life cycle (i.e., aquatic vascular plant species 

obligates). Reducing the proposed application rate from 0.045 Ib a.i./acre to 0.040 lb 

a.i./acre, however, results in a peak EEC of 8.9 ppb using the TX Wheat scenario. 

Therefore, at a maximum application rate of 0.040 lb a.i.lacre, risks to listed aquatic 

vascular plants are not expected. 

There is no evidence of pyrasulfotole degradation in aquatic environments. As such, 

pyrasulfotole was assumed stable in the ecological pond used to estimate aquatic 

exposure concentrations. Since the ecological pond (used in our modeling) has no outlet, 

there was a modeled accumulation of pyrasulfotle in the pond throughout the 30 year 

simulations. In the case of persistent compounds, a 1 -in- 10 year EEC does not reflect 

varying meteorological conditions that are expected once every ten years, since the yearly 

peaks are not independent but are actually correlated to the previous year's peak 

concentration. This results in acute and chronic exposure concentrations that are very 

similar (i.e, < 2% difference between peak and 90-day average EECs). Estimated peak 

concentrations in the ecological pond are only high enough to result in an exceedance of 

the listed species LOC for vascular plants after 26 years of annual applications of 

pyrasulfotole assuming no dissipation whatsoever in the pond (APPENDIX C). 

Pyrasulfotle concentrations in flowing water bodies are not expected to accumulate from 

year to year because of downstream dilution. Risk to aquatic plants resulting from 

accumulation of pyrasulfotle from multiple years of application is not likely in flowing 

systems. 
2. Risks to Terrestrial Organisms 

a. Animals 

Birds 

The avian chronic risk LOC (which is the same for listed and non-listed species) is not 

exceeded for any pyrasulfotole use indicating that the likelihood of adverse effects on 

birds due to chronic exposure is low. Because there was no mortality or sublethal effects 

at the highest treatment levels tested in the acute oral and sub-acute dietary avian studies 

submitted, standard RQ values for acute and sub-acute exposure were not calculated in 

the Risk Characterization section of this assesssment. In order to gain a better 

understanding of how the EECs for the maximum proposed pyrasulfotole application rate 

relate to the toxicity data currently available for birds, we used T-REX to calculate RQs 

using the conservative assumption that the highest values tested in the avian studies 

represent endpoints (i.e., acute: LDso = 2,000 mg/kg-bw; sub-acute: LCsO = 4,911 mglkg 

diet). In this exercise all of the acute and sub-acute RQs calculated using upper bound 

Kenaga values were between 0 and 0.01 for all size and dietary classes. The actual RQs 

would be much lower than these since no effects were actually identified at the 2,000 

mag-bw and the 4,911 mglkg diet levels. Therefore, direct risk to birds from acute, 

sub-acute, or chronic exposure to pyrasulfotole is low. Given the potential for effects on 

terrestrial and aquatic plant species associated with the use of pyrasulfotole, however, 

indirect effects on birds are possible. 

Mammals 

Because there was no mortality at the highest treatment levels tested in the acute oralexposure mammalian study submitted, standard RQ values for acute exposure were not 

calculated in the Risk Characterization section of this assessment. In order to gain a 

better understanding of how the EECs for the maximum proposed pyrasulfotole 

application rate relate to the toxicity data currently available for mammals, we used TREX to calculate RQs using the conservative assumption that the highest values tested in 

the avian studies represent endpoints (i.e., acute: LDsO = 2,000 mglkg-bw). In this 

exercise all of the acute RQs calculated using upper bound Kenaga values were 0 for all 

size and dietary classes. Using the the effect level of 500 mgkg-bw in for increased 

incidents of corneal opacity and corneal neovascularization in females and retinal 

degeneration in males results in dose-based RQs from T-REX between 0 and 0.01 for all 

sizeldietary categories. Therefore, direct risk to mammals from acute exposure to 

pyrasulfotole is low. 

The Agency's chronic risk LOC was exceeded for three body sizeldiet categories [I 5 g 

and 35 g mammals that eat short grass (RQs = 1.87 and 1.6, respectively) and 15 g 

mammals that eat broadleaf plantslsmall insects (RQ = 1.05)], based on a reproductive 

NOAEL of 2.5 mgkg bwlday. This NOAEL is based on delays in maturation 

(specifically delayed balano-preputial separation) and diffuse and reticulate corneal 

opacity in pups (LOAEL = 26.3 mgkg bwlday in males and 32.6 mgkg-bwlday in 
females). Similar effects were seen in a 21 -day Wistar rat developmental neurotoxicity 

study [NOAEL = 3.8 mgkg-bwlday based on decreased food consumption during 

lactation and ocular opacities in dams; and decreased postnatal weights, delayed preputial 

separation, decreased brain weights and retinal degeneration in offspring at the highest 

treatment levels (37 and 354 mag-bwlday)]. A supplemental 24-month chronic toxicity 

study with Wistar rats failed to establish a NOAEC because of effects at the lowest 

treatment level (25 mgfkg-diet), including increased incidences of corneal opacity and 

neovascularization of the cornea. 

It is unclear specifically how decreases in vision resulting from corneal opacity and 

retinal degeneration would affect the viability of mammals. Additionally, some of the 

eye effects (specifically the corneal effects) observed in the rat studies are believed to be 

the result of increased tyrosinemia from HPPDase inhibition. Since different species are 

known to differ in their metabolism of tyrosine, it is unclear if rats are more susceptible 

to these eye abnormalities than other animals exposed to pyrasulfotole. For example, no 

eye disorders were observed in a submitted teratogenicity test in rabbits (MRID: 

46801 906). The delayed maturation exhibited by the delays in balano-preputial 

separation, however, can be more clearly linked to potential adverse reproductive effects. 

Therefore, some mammals, specifically smaller-bodied (<35 g) mammals that eat short 

grass, broadleaf plants, or small insects, are potentially at risk from chronic exposure to 

pyrasulfotole (based on the maximum proposed application rate for cereal grains). 

Reducing the maximum application rate for pyrasulfotole to 0.023 lb a.i./acre results in 

chronic RQs of <l for all mammalian sizeldietary categories. Based on T-REX, the 

highest RQ for effects to mammals from chronic exposure to pyrasulfotole is 0.96 for 15g 

mammals that eat short grass (see APPENDIX D). Therefore, potential risks to listed 

and non-listed mammals (from chronic exposure to pyrasulfotole) are not expected at 

application rates 50.023 lb a.i./acre. 

Terrestrial Invertebrates 

EFED does not currently estimate risk quotients for terrestrial non-target invertebrates. 

However, a label statement is required to protect foraging honeybees when the LDS0 is < 

11 pghee. Based on the acute contact toxicity study to honeybees, the LDso for 

pyrasulfotole is >75 pghee. This classifies pyrasulfotole as practically non-toxic to 

honeybees on an acute contact exposure basis. Additionally, in all of the terrestrial 

invertebrate studies there was no mortality or sublethal effects in any of the treatment 

levels tested. Therefore, the risk for direct adverse effects to terrestrial invertebrates is 

considered low; however, due to the risk to plants, the potential for indirect effects to 

terrestrial invertebrates from pyrasulfotole use cannot be discounted. 

b. Plants 

Tier I1 plant studies demonstrate the potential for pyrasulfotole to affect terrestrial dicot 

plants. In the vegetative vigor studies, the exposure levels equivalent to a 25% effect 

level were 0.017 lbs a.i./A for monocots and 0.00081 lbs a.i./A for dicots, based on the 
study with the AE 03 17309 SE06 formulation. Results from the seedling emergence 

study indicated that a 25% effect level was 0.001 1 Ibs a.i./a for dicots (no effects were 

seen in monocots). None of the RQs for monocots, which range from 0.03 to 0.99, 

exceed the Agency's LOC of >l for plants. However, the RQs for semi-aquatic 

monocots approached the Agency's LOC of 1 for listed species (RQs = 0.92 and 0.99 for 

ground and aerial applications, respectively). These RQs were calculated based on the 

NOAEC for ryegrass which showed no effects at the highest treatment level tested 

(0.0249 Ib a.i./acre; approximately half of the proposed maximum application rate) in a 

seedling emergence study. Therefore, the actual no effect level would likely be higher, 

which would result in a lower RQ. Furthermore, pyrasulfotole showed no adverse effects 

on the other monocot species tested in the seedling emergence studies at rates up to 0.10 

lbs a.i./acre (more than twice the proposed maximum application rate). Therefore, the 

potential risk to listed semi-aquatic monocot species is considered low. 

All of the RQs for listed and nonlisted terrestrial and wetland dicots in areas adjacent to 

pyrasulfotole use sites do exceed the Agency's LOC. Additionally, the LOC is exceeded 

for the RQ for listed dicots based on drift alone for aerial applications. 

Regarding the AE 03 17309 + Bromo formulation [which contains three active 

ingredients: 3.3% pyrasulfotole, 13.4% bromoxynil octanoate, and 12.9% bromoxynil 

heptanoate], monocots are less sensitive and dicots are more sensitive when compared to 

the AE 03 17309 SE06 formulation [which contains only one active ingredient: 4.4% 

pyrasulfotole]. Because AE 03 17309 + Bromo formulation is a mixture of different 

active ingredients, the results from the studies using this formulation cannot be used to 

assess the risks to plants from pyrasulfotole use specifically, although the results are 

reported as Ibs of pyrasulfotole/acre. The results, however, can be used to help assess the 

risk of the formulated product to plants. Table 20 compares the RQs for dicots for the 

AE 03 17309 SE06 and AE 03 17309 + Bromo formulations based on TerrPlant v. 1.2.1. 

Since monocots are less sensitive to the AE 03 17309 + Bromo formulation than to the 

AE 03 17309 SE06 formulation, only the results for dicots are presented below. 

To gain a better understanding of the potential for spray drift to affect terrestrial dicots, 

AgDRIFT (v. 2.01) Tier 111 aerial modeling was used to determine how far off-field 

pyrasulfotole levels would remain above the EC25 for vegetative vigor of dicotyledonous 

plants. A~DRIFT~ utilizes empirical data to estimate off-site deposition of aerial and 

TABLE 20. Comparison of RQ Values for Terrestrial and Semi-Aquatic Dicots 

Exposed to the AE 0317309 SE06 and AE 0317309 + Bromo formulations. 

TAXA 

Nonlisted 

Species 

Listed 

Species 

Bolded numbers indicate RQs that exceed the Agency's LOC for plants. 

APPLICATION 

METHOD 

Ground 

Aerial 

Ground 

Aerial 

ADJACENT 

UPLAND 

AE 

0317309 

+Bromo 

10.8 

18 

10.09 

16.82 

ADJACENT 

WETLAND 

AE 

0317309 

SE06 

2.45' 

4.09 

6.77 

11.28 

AE 

0317309 + 

Bromo 

91.8 

99 

85.77 

92.5 

DRIFT ONLY 

AE 

0317309 

SE06 

20.86 

22.5 

57.52 

62.03 

AE 

0317309 + 

Bromo 

2.65 

13.24 

23.13 

115.63 

AE 

0317309 

SE06 

0.01 

0.06 

0.56 

2.82 
ground applied pesticides. Details concerning the specifics and uncertainties of 

AgDRIFT are available online at www.agdrift.com. The default 'Maximum Downwind 

Distance' for AgDRIFT is 2,608 ft, however, this parameter can be changed to 1 mile in 

Tier I11 modeling with the understanding that any calculations beyond 2,608 ft increases 

the uncertainty associated with the results. For the AE 03 17309 SE06 formulation, 

assuming the maximum single application rate of 0.045 lbs a.i./A, ASAE Fine to Medium 

droplet size distribution (an ASAE Medium droplet size distribution is stipulated on the 

label), 10 mph winds, and 10 ft application height, dicots 390 ft or closer to the treated 

use area may be exposed to pyrasulfotole levels above the EC25 (0.001 1 lbs a.i./acre) (for 

specific input parameters, see APPENDIX G). If droplet size distribution was increased 

to ASAE Medium to Coarse, the distance from the treated site where spray drift might 

exceed the EC25 is 203 ft. For the AE 03 17309 + Bromo formulation, assuming the 

maximum single application rate of 0.037 lbs a.i. (pyrasulfotole only)/A, ASAE Fine to 

Medium droplet size distribution (an ASAE Medium droplet size distribution is stipulated 

on the label), 10 mph winds, and 10 ft application height, dicots 2,126 ft or closer to the 

treated use area may be exposed to pyrasulfotole levels above the EC25 [0.00025 lbs a.i. 

(pyrasulfotole only)/acre]. For listed dicot species, these distances would be greater. 

For ground applications (Tier I), high boom, ASAE Fine to MediumICoarse droplet size 

distribution, 9oth data percentile, dicots within 23 ft and 105 ft to the treatment site (for 

the AE 03 17309 SE06 and AE 03 17309 + Bromo formulation, respectively) are predicted 

to be exposed to pyrasulfotole levels above the EC25. Again, for listed dicot plant 

species, the distances would be greater. 

Therefore, the potential for adverse effects of pyrasulfotole use to listed and non-listed 

dicotyledonous plants extend well beyond the treatment site for both aerial and ground 

applications. 

3. Review of Incident Data 

There are no reports of ecological incidents for pyrasulfotole in the EIIS (Environmental 

Incident Information System) database. Because this is a new chemical that has not been 

registered for use in the United States, the existence of such incident reports would be 

unlikely. 

4. Federally Threatened and Endangered (Listed) Species Concerns 

a. Action Area 

For listed species assessment purposes, the action area is considered to be the area 

affected directly or indirectly by the Federal action and not merely the immediate area 

involved in the action. At the initial screening-level, the risk assessment considers 

broadly described taxonomic groups and conservatively assumes that listed species 

within those broad groups are located on or adjacent to the treated site and 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 
that has the relatively highest potential exposure to the pesticide, and that exposures are 

likely to decrease with distance from the treatment area. 

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 upon listed species that depend upon the 

taxonomic group covered by the RQ as a resource. 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 could be considered to determine the extent to 

which screening assumptions regarding an action area apply to a particular listed 

organism. These subsequent refinement steps could consider how this information would 

impact the action area for a particular listed organism and may potentially include areas 

of exposure that are downwind and downstream of the pesticide use site. 

b. Taxonomic Groups Potentially at Risk 

The Level I screening assessment process for listed species uses the generic taxonomic 

group-based process to make inferences on direct effect concerns for listed species. The 

first iteration of reporting the results of the Level I screening is a listing of pesticide use 

sites and taxonomic groups for which RQ calculations reveal values that meet or exceed 

the listed species LOCs (for more inforrnation see, USEPA 2004). 

(1). Discussion of Risk Quotients 

None of the Agency's acute listed species LOCs or chronic listed species LOCs were 

exceeded for any group of terrestrial or aquatic non-mammalian animal for any 

pyrasulfotole use. Additionally, the listed species LOC for plants was not exceeded for 

monocots or for any non-vascular aquatic plant. The Agency's listed species LOC, 

however, was exceeded for fieshwater vascular plants, the listed species and acute risk 

LOCs were exceeded for dicots, and the chronic risk (for listed and non-listed species) 

was exceeded for some mammals at the maximum proposed application rate for 

pyrasulfotole. This indicates a potential risk for direct adverse effects to Federally-listed 

dicots, fieshwater vascular plants, and mammals and indirect adverse effects to any listed 

species that rely on these taxa as resources critical to their life cycle. 

(2). Probit Dose Response Relationship 

Although no acute LOCs were exceeded for any animal, indicating a low acute risk to 

these taxa, the probit slope response relationship can be used to calculate the chance of an 

individual event corresponding to the listed species acute LOCs and/or RQs. The 
analysis uses the EFED spreadsheet IECvl . 1 .xls. It is important to note that the IEC 

model output can go as high as 1 x 1016 or as low as 1 x 10-l6 in estimating the event 

probability for animals. This cut-off is a limit in the Excel spreadsheet environment and 

is not to be interpreted as an agreed upon upper or lower bound threshold for concern for 

individual effects in any given listed species. 

If information is unavailable to estimate a slope from a study, a default slope assumption 

of 4.5 is used as per original Agency assumptions of typical slope cited in Urban and 

Cook (1986). Slopes were not available for the acute toxicity studies on freshwater fish, 

freshwater invertebrates, estuarinelrnarine fish, birds, mammals, and terrestrial 

invertebrates. Therefore, probit-dose analyses were done based on the taxon-specific 

acute listed species LOCs and a default slope of 4.5 to estimate an individual effects 

probability for freshwater fish, freshwater invertebrates, estuarinelrnarine fish, birds, 

mammals, and terrestrial invertebrates. This resulted in a chance of 1 in 41 8,000,000 for 

freshwater fish, freshwater invertebrates, estuarinelmarine fish, and terrestrial 

invertebrates, and 1 in 1 in 294,000 for birds and mammals. To explore possible bounds 

to such an estimate, slopes of 2 and 9 were used to calculate upper and lower estimates of 

the effects probability associated with the listed species LOC. The chance of individual 

effects with these slopes ranged from 1 in 44 to 1 in 1 in 1.75E+ 1 for the various taxa 

(see Table 21). 

The only animal taxonomic group for which a probit slope is available is 

estuarinelrnarine invertebrates [based on an ECso of 1.1 mg a.i./L for the mysid 

(Americamysis bahia) (MRID: 468017-23)]. The probit slope in this study was 2.23 with 

a 95% confidence limit of 1.66 and 2.8. The corresponding estimated chance of 

individual mortality associated with a slope of 2.23 and the listed species LOC of 0.05 is 

1 in 538. To explore possible bounds to such an estimate, the upper and lower 95% 

confidence limits for the probit slope estimate (1.66 and 2.8) were used to calculate upper 

and lower estimates of the effects probability associated with the listed species LOC. 

These values are 1 in 65 and 1 in 7,420, respectively (see Table 21). 
TABLE 21. Chance of an Individual Effect Corresponding to the Listed Species - 

Acute LOCs Using a Probit Slope Response Relationship. 

TAXA I LOC I PROBIT SLOPE I CHANCE OF AN INDIVIDUAL I 

I EFFECT 

- Freshwater Invertebrates 

- Estuarinemarine Fish 

- Freshwater Fish 1 0.05 1 Slo~e 1 4.5' 1 1 in 418.000.000 L - , , 

Upper Bound 1 2 I 1 in216 

Lower Bound 1 9 1 1 in 1.75E+3 1 

- Terrestrial ~nvertebrates' 

- Estuarinemarine 

Invertebrates 

I 1 in 8.86E+18 ' The Agency does not currently have a listed-species LOC for terrestrial invertebrates; for our purposes 

- Birds 

- Mammals 

here, we use the aquatic invertebrate acute listed-species LOC (RQ > 0.05). 

This is the deafault slope. 

0.05 

(3). Indirect Effects Analysis 

0.1 

The Agency acknowledges that pesticides have the potential to exert indirect effects upon 

listed organisms by, for example, perturbing forage or prey availability, altering the 

extent of nesting habitat, and creating gaps in the food chain. In conducting a screen for 

indirect effects, direct effect LOCs for each taxonomic group are used to make inferences 

concerning the potential for indirect effects upon listed species that rely upon non-listed 

organisms in these taxonomic groups as resources critical to their life cycle. 

Slope 

Upper Bound 

The Agency's listed species LOC was exceeded for freshwater vascular plants, the listed 

species and acute risk LOCs were exceeded for dicots, and the chronic risk LOC (for 

listed and non-listed species) was exceeded for some mammals 5 35 g at the maximum 

proposed application rate for pyrasulfotole. Therefore, EFED's screening level analysis 

shows that the possibility of indirect effects from the proposed use of pyrasulfotole on 

cereal grains to listed species (generalists and obligates) that may depend on dicots and/or 

mammals and obligates that rely on aquatic vascular plants for survival cannot be 

precluded. Therefore, at this time, no Federally-listed taxa can be excluded from the 

potential for direct and/or indirect effects from the proposed uses of pyrasulfotole (see 

Table 22). Species-specific concerns for indirect effects to listed organisms will require 

a determination of the coincidence of pyrasulfotole use with locations of listed species 

and the biologically based resources upon which they depend. 

Lower Bound 

Slope 

Uooer Bound 

2.23 

1.66 

1 in 538 

1 in 64.9 

2.8 

4.52 

2 

- p~ 

1 in 7,420 

1 in 294,000 

1 in 44 
TABLE 22. Listed Species Risks Associated with Potential Direct or Indirect 

Terrestrial and semi-aquatic 

plants - dicots 

LISTED TAXON 

Terrestrial and semi-aquatic 

~lants - monocots 

Yes 

DIRECT EFFECTS 

No 

Terrestrial phase amphibians 

INDIRECT EFFECTS 

yes1 

- - 

Insects 

Birds 

Effects Due to the Proposed Applications of Pyrasulfotole on Cereal Grains. 

I 

- 

1 - 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

No 

No 

Reptiles 

Mammals 

Aquatic plants 

yes1 

yes' 

No 

Yes (chronic) 

Yes 

Freshwater fish 

Aquatic phase amphibians 

Freshwater crustaceans 

yes' 

yes' 

yes' 

Mollusks 

(4). Critical Habitat 

No 

No 

No 

Marinelestuarine fish 

Marinelestuarine crustaceans 

In the evaluation of pesticide effects on designated critical habitat, consideration is given 

to the physical and biological features (constituent elements) of a critical habitat 

identified by the U. S. Fish and Wildlife and National Marine Fisheries Services (the 

yes' 

yes' 

yes' 

No yes1 

 he nonlisted LOC was exceeded for terrestrial and semi-aquatic plants (dicots), the listed LOC was 

exceeded for aquatic vascular plants, and the chronic risk LOC was exceeded for some small mammals 

(95 g) . Therefore, the potential for adverse effects to those species that rely either on a specific plant or 

animal species (specifically aquatic vascular plants, terrestriallsemi-aquatic dicots, or mammals) or 

multiple plant or animal species (specifically terrestriaysemi-aquatic dicots and mammals) cannot be 

precluded. Indirect effects may include general habitat modification, host plant loss, and food supply 

disruption. 

No 

No 

yes' 

yes' 
Services) as essential to the conservation of a listed species and which may require 

special management considerations or protection. The evaluation of impacts for a 

screening level pesticide risk assessment focuses on the biological features that are 

constituent elements and is accomplished using the screening-level taxonomic analysis 

(RQs) and levels of concern (LOCs) that are used to evaluate direct and indirect effects to 

listed organisms. 

The screening-level risk assessment has identified potential concerns for indirect effects 

on listed species for those organisms dependant upon plants and some mammals. In light 

of the potential for indirect effects, the next step for EPA and the Services is to identify 

which listed species and their designated critical habitat(s), if applicable, are potentially 

implicated. Analytically, the identification of such species and their critical habitat can 

occur by determining whether the action area overlaps designated critical habitat or the 

occupied range of any listed species. If so, EPA would examine whether the pesticide's 

potential impacts on non-listed species would affect the listed species indirectly, or 

directly affect a constituent element of the critical habitats. At present, the information 

reviewed by EPA does not permit use of this analytical approach to make a definitive 

identification of species that are potentially impacted indirectly or designated critical 

habitats that are potentially impacted directly by the proposed uses of pyrasulfotole. 

This screening-level risk assessment for critical habitats provides a listing of potential 

biological features that, if they are constituent elements of one or more critical habitats, 

would be of potential concern. These correspond to the taxa identified above (i.e., dicots, 

aquatic vascular plants, and mammals) as being of potential concern for adverse effects. 

This should serve as an initial step in problem formulation for further assessment of 

designated critical habitat impacts outlined above, should additional work be necessary. 

(5). Co-occurrence Analysis 

The goal of the analysis for co-location is to 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 actually apply to a 

'species', 'subspecies', or an Evolutionary Significant Unit (ESU)]. At the screening 

level, this analysis is accomplished using the LOCATES (version 2.10.3) database. The 

database uses location information for listed species at the county level and compares it 

to agricultural census data (fiom 2002) for crop production at the same county level of 

resolution. The product is a listing of Federally-listed species that are located within 

counties known to produce the crops upon which the pesticide will be used, in this case 

cereal grains (i.e., wheat, barley, oats, and triticale). For direct effects, only listed dicots, 

aquatic vascular plants, and mammals will be considered, since they were the only taxa to 

have RQs above the listed species LOC. For indirect effects, all other taxa will be 

considered since there is a potential for indirect effects to taxa that might rely on plants 

and/or mammals for some stage of their life-cycle. 

LOCATES identified a total of 8 17 listed species that overlapped at the county-level with 

areas where wheat, barley, oats, and/or triticale are grown. Among these species, 3 18 are 
dicots, 13 are aquatic monocots, and 59 are mammals (see APPENDIX H for a complete 

species list). Therefore, at the county-level, there is the potential for a total of 390 listed 

species to be directly affected by pyrasulfotole use, while 427 species may be indirectly 

affected by the use of the chemical. The number of county co-occurrences by taxa per 

state can be found in Table 23. 

This preliminary analysis indicates that there is a potential for pyrasulfotole 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 pyrasulfotole and 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. 

C. Description of Assumptions, Limitations, Uncertainties, Strengths 

and Data Gaps 

A source of uncertainty is the nature of the unextractable residues formed during 

pyrasulfotole degradation in soils. In aerobic soil metabolism studies unextractable 

residues were identified at maximums of 35-62% of applied radioactivity in three soils. 

The unextractable residues are uncharacterized and it is uncertain whether they consist of 

degradates of risk concern. Under sterile conditions these unextractable residues were 

not formed suggesting that the formation of them is microbially mediated. Aerobic soil 

metabolism half-lives were estimated based on parent concentrations alone (excluding 

unextractable residues). To the extent that these unextractable residues are of risk 

concern, the estimated half-lives will be underestimated compared to a total toxic residue 

approach for estimating half-lives. However, given the persistence of pyrasulfotole 

parent only, a total toxic residue approach for calculating aerobic soil metabolism halflife would not impact PRZMIEXAMS modeled EECs appreciably. In fact, assuming 

pyrasulftole is completely stable to aerobic soil metabolism results in peak EECs for the 

TX wheat scenario that are identical (to two significant figures) to those used in this 

assessment. 

The ecological pond modeled with EXAMS is a static water body of fixed volume with 

no outlet. Since pyrasulfotole is persistent in aquatic environments and since the 

ecological pond has no outlet, there was a modeled accumulation of pyrasulfotle in the 

pond throughout the 30 year simulations. Exposure endpoints, in this assessment, are 

based on yearly peak concentrations. In the case of persistent compounds, a 1 -in- 10 year 

EEC does not reflect varying meteorological conditions that are expected once every 10 

years, since the yearly peaks are not independent but are actually correlated to the 

previous year's peak concentration. Estimated peak concentrations in the ecological 

pond are only high enough to result in an exceedance of the listed species LOC for 

vascular plants after 26 years of annual applications of pyrasulfotole assuming no 

dissipation whatsoever in the pond (APPENDIX C). Pyrasulfotle concentrations in 

flowing water bodies are not expected to accumulate from year to year because of 

downstream dilution. Risk to aquatic plants resulting from accumulation of pyrasulfotle 

from multiple years of application is not likely in flowing systems. 

Even though pyrasulfotole is very soluble and moderately mobile to mobile based on the 

results of batch equilibrium studies, in aquatic systems it does variably partition to the 

sediment and forms unextractable residues and persists as parent. Additionally, there is 

some evidence that pyrasulfotle may become less mobile as it it is exposed to viable 

microbs under certain conditions. Since PRZMIEXAMS modeling requires one input for 

soil-water partitioning coefficient that is constant throughout the simulation, the modeled 

partitioning to the sediment may be underestimated relative to the aerobic aquatic 

metabolism studies. Therefore, there may be a potential for pyrasulfotole (andlor 

residues) to accumulate in the benthos at levels that could result in toxic exposure to 

benthic and epibenthic aquatic organisms, especially those that consume soil (e.g., 

Hexagonia spp.). The potential risk to benthic and epibenthic organisms could not be 

assessed here, however, because a lack of available toxicity data for these taxa. 
Therefore, risks to benthic and epibenthic organisms from the use of pyrasulfotole on 

cereal grains cannot be precluded at this time. 

Related to these issues, estuarinelrnarine invertebrates (i.e., mysids) are considerably 

more sensitive to pyrasulfotole on an acute exposure basis than the other aquatic animals 

tested. The reason(s) for this difference in toxicity is not clear. Because no toxicity data 

for chronic exposures are available for estuarinelrnarine invertebrates and toxicity data 

from a freshwater invertebrate do not appear to be a good surrogate for measures of 

toxicity in this taxon, there is the potential for adverse effects to estuarinelrnarine 

invertebrates from chronic exposure to pyrasulfotole (especially since it could accumulate 

in the benthos). However, given that: (1) the potential use sites for the proposed uses 

largely fall outside of estuarinelrnarine environments, with the possible exceptions of CA 

and the mid-Atlantic states; (2) the aquatic EECs used in this assessment are based on a 

static water-body with no outlet, and, thus, would likely be higher than those in 

estuarinelrnarine environments; and (3) estuarinelrnarine invertebrates would need to be 

1,293 times more sensitive to pyrasulfotole than freshwater invertebrates on a chronicexposure basis to exceed the Agency's chronic risk LOC, risks to estuarinelrnarine 

invertebrates from chronic exposure to pyrasulfotole are not expected. However, the lack 

of data on the chronic toxicity of pyrasulfotole to estuarinelrnarine invertebrates does add 

uncertainty to this risk assessment. 

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MRID: 46801 7-37 

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Laboratory report number EBAIXOOS (A9883501). Study sponsored by Bayer CropScience, 

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MRD: 468017-38 

Kern, M.E. and C.V. Lam. 2004. Toxicity of AE 0317309 Technical to the Freshwater Diatom 

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Development Department, Stilwell, KS. Laboratory report number EBAIX006 (A9883401). 

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MRID: 46801 7-39 

Kern, M.E., C.S. Banman and C.V. Lam. 2004. Toxicity of AE 03 17309 Technical to the BlueGreen Algae Anabaena,flos-aquaea. Unpublished study performed by Bayer CropScience, 

Research and Development Department, Stilwell, KS. Laboratory report number EBAAIX008 

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MRID: 4680 17-40 

Kern, M.E., C.S. Banman and C.V. Lam. 2004. Toxicity of AE 0317309 Technical to the 

Saltwater Diatom Skeletonema costatum. Unpublished study performed by Bayer CropScience, 

Research and Development Department, Stilwell, KS. Laboratory report number EBAAIX007 

(A9883601). Study sponsored by Bayer CropScience, Research Triangle Park, NC. 

MRID: 46801 7-41 

Lechelt-Kunze, C. 2004. AE 03 17309, substance, technical (Code: AE 03 17309 00 1 C96 0001): 

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performed by Bayer CropScience AG, Institute for Ecotoxicology, Monheim, Germany. Study 

No. E 3 10 267 1-0. Study sponsored by Bayer CropScience AG, Monheim, Germany. 

MKID: 46801 836 

Schungel, M. (2004) AE 0317309: Acute Toxicity in the Rat After Oral Administration. Project 

Number: AT01 067, Tl3073706, TXAIM001. Unpublished study prepared by Bayer Ag Inst. of 

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MRID: 46801 907 

Eiben, R. (2005) Two-Generation Reproduction Study in the Wistar Rat by Administration in the 

Diet. Project Number: T2063193, TXAIXOO5, AT02705. Unpublished study prepared by Bayer 

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MRID: 46801917 

Gilmore, R.; Sheets, L.; Hoss, H. (2006) A Developmental Neurotoxicity Screening Study with 

Technical Grade AE 03 17309 in Wistar Rats. Project Number: 04/D72NE1 201439. Unpublished 

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MRID: 46801 9-26 

Pallet, K and H. Gosch. 2006. Non-target terrestrial plants: Seedling emergence and growth test 

(Tier 2) Suspo-emulsion: 50+12.5 g/L (Code: AE 031 7309 02 SE06 A1 02). Unpublished study 

performed by Bayer CropScience GmbH, Frankfurt am Main, Germany. Laboratory study 

number SE041006. Study sponsored by Bayer CropScience GmbH, Frankfurt am Main, 

Germany. 

MRID: 468019-27 

Pallet, K. and H. Gosch. 2006. Non-target terrestrial plants: Vegetative vigor test (Tier 2) AE 

03 17309 + Mefenpyr di-ethyl (AE F107892); Suspo-emulsion: 50+12.5 g/L (Code: AE 03 17309 

02 SE06 A102). Unpublished study performed by Bayer CropScience GmbH, Ecotoxicology, 

Frankfurt am Main, Germany. Laboratory report number VV04/005. Study sponsored by Bayer 

CropScience GmbH, Ecotoxicology, Frankhrt am Main, Germany. 

MRID: 4680 19-36 

Pallet, K. and H. Gosch. 2006. Non-target terrestrial plants: Seedling emergence and seedling 

growth test (Tier 2); AE 0.31 7309+Mefenpyr di-ethyl+Bromoxynil (Code: AE 03 17309 03 EC23 

A8). Unpublished study performed by Bayer CropScience GmbH Ecotoxicology, Frankfurt am 

Main, Germany. Laboratory report number SE 05/00 1. Study sponsored by Bayer CropScience 

GmbH Ecotoxicology, Frankfurt am Main, Germany. 

MRID: 468019-37 

Pallet, K. and H. Gosch. 2006. Non-target terrestrial plants: Vegetative Vigor test (Tier 2), AE 

03 17309+Mefenpyr di-ethyl+Bromoxynil (Code: AE 03 17309 03 EC23 A8). Unpublished study 

performed by Bayer CropScience GmbH, Frankfurt am Main, Germany. Laboratory report 

number VV 05/002. Study sponsored by Bayer CropScience GmbH, Frankfurt am Main, 

Germany. 

MRID: 4680 19-37 

Dobbs, M.G., M. Lenz, B. Meyer, and J-Z. Tang. 2006. Ecological risk assessment for the cereal 

herbicide AE 03 17309. Unpublished study performed by Bayer CropScience, , Research 

Triangle Park, NC. Laboratory Study No. EBAIP004. Study submitted by Bayer CropScience, 

Research Triangle Park, NC. 

MRID: 4680 1703 

Maurer, T.; Eyrich, U.; Fliege, R. (2003) Adsorption/Desorption of AE 03 17309 on Five Soils 

and One Sediment. Project Number: CPI02l014, M0/03/012996, MEF/186/03. Unpublished 

study prepared by Bayer Cropscience Gmbh. 84 p. 

MRID: 46801 705 

Ripperger, R. (2004) [Pyrazole-3-(Carbon 14)] AE03 17309: Hydrolytic Degradation. Project 

Number: 200578, A9072401. Unpublished study prepared by Bayer Corp. 59 p. 

MRID: 4680 1706 

Ripperger, R.; Meyer, B. (2005) [(Carbon 14)-UL-Phenyl] and [(Carbon 14)-3-Pyrazole] AE 

03 17309: Phototransformation in Water. Project Number: 200987, A9082401. Unpublished study 

prepared by Bayer Corp. 64 p. 

MRID: 46801717 

Lenz, M. (2006) Terrestrial Field Dissipation of AE 03 17309 in North Dakota Soil, 2004. Project 

Number: MEAIY007, AI/002/S05/02. Unpublished study prepared by Bayer Corp. and Agvise 

Inc. 188 p. 

MRID: 46801 71 8 

Lenz, M. (2006) Terrestrial Field Dissipation of AE 0317309 in Washington Soil, 2004. Project 

Number: MEAIY009, AI/002/S05/02. Unpublished study prepared by Bayer Corp., Agvise Inc. 

and Qualls Agricultural Laboratories, I. 195 p. 

MRID: 46801719 

Belyk, M. (2006) Terrestrial Field Dissipation of AE 03 17309 in Canada, 2003-2004. Project 

Number: 03BCS01, MEAIM004, AI/002/S05/01. Unpublished study prepared by Bayer Corp., 

Vaughn Agricultural Research Serv., Ltd. and Ag-Quest Inc. 333 p. 
APPENDIX A: ECOTOX Results 

All of the references identified by ECOTOX were excluded because they were not 

written in English. 

Dollinger, Markus, Santel, Hans-Joachim, Gesing, Ernst Rudolf, and Hacker, Erwin 

(20050922). Synergistic herbicidal compositions comprising thien-3-ylsulphonylamino(thio)carbonyl-triazolin(thi)one derivatives and 4-HPPD inhibitors. 

(Bayer Cropscience Ag, Germany) PCT Int. Appl. 3 1 pp. 

Chem Codes: Chemical of Concern: PST Reiection Code: NON-ENGLISH. 

Huff, Hans Philipp, Hacker, Erwin, Bojack, Guido , Fischer, Reiner, Feucht, Dieter, and 

Lehr, Stefan (20060302). Herbicidal compositions comprising ketoenols. (Bayer 

Cropscience G. m. b. H., Germany) Ger. Ofen. 3 1 pp. 

Chem Codes: Chemical of Concern: PST Reiection Code: NON-ENGLISH. 

Schmitt, Monika, Van Almsick, Andreas, Preuss, Rainer, Willms, Lothar, Auler, Thomas, 

Bieringer, Herrnann, and Thuenvaechter, Felix (2001 101 1). Benzoylpyrazoles and their 

use as herbicides. (Aventis CropScience GmbH, Germany) PCT Int. Appl. 32 pp. 

Chem Codes: Chemical of Concern: PST Reiection Code: NON-ENGLISH. 

Schmitt, Monika, Willms, Lothar, Ziemer, Frank, Rosinger, Christopher, Bieringer, 

Herrnann, Huff, Hans Philipp, and Hacker, Erwin (20030530). Herbicidal compositions 

containing benzoylpyrazoles and safeners. (Bayer CropScience GmbH, Germany) PCT 

Int. Appl. 30 pp. 

Chem Codes: Chemical of Concern: PST Rejection Code: NON-ENGLISH. 
APPENDIX B: Environmental Fate and Transport Study Details 

Abiotic Degradation 

Hydrolysis 

In an acceptable study (MRID 46801705), the hydrolysis of pyrasulfotole at 0.14 

mg a.i./L, was studied in the dark at 24.9 k 0.02"C in sterile aqueous buffered pH 5, pH 

7, and pH 9 solutions for 30 days. [14~]-~yrasulfotole avraged 98.4-100.4% of the 

applied in the pH 5 solutions and 98.6-100.3% in the pH 7 solutions throughout the 

experiment. In the pH 9 solution, [14~]-pyrasulfotole averaged 96.6-98.1 % of the applied 

through 22 days posttreatment and 95.7% at 30 days. Half-lives were not calculated 

because pyrasulfotole was stable to hydrolysis. 

Aqueous Photolysis 

In an acceptable study (MRID 46801706), the aqueous phototransformation of 

pyrasulfotole at ca. 1 mg a.i./L, was studied in sterile pH 7 buffer (0.01M phosphate) at 

25 k 1 "C under continuous irradiation using a UV-filtered xenon arc lamp for 2 12 hours. 

['4~]-~yrasulfotole (both labels) did not degrade in either the irradiated or dark control 

solutions. In the irradiated solutions, [14~]-pyrasulfotole ranged from an average of 

97.7% to 100.7% of the applied with no pattern of decline during the 9-day experiment. 

In the dark controls, [14~]-pyrasulfotole ranged from an average 99.6% to 102.0% of the 

applied with no pattern of decline. A half-life was not calculated because pyrasulfotole 

was stable in both the irradiated and dark control solutions. 

Soil Ph otolysis 

In an acceptable study (MRID 46801 707), the phototransformation of 

pyrasulfotole, at 0.51 mglkg (equivalent to 75 g a.i./ha), was studied on silt loam soil [pH 

7.4, organic matter 7.1 %] from North Dakota that was irradiated continuously using a 

UV-filtered xenon lamp for 9 days at 25 * 0.1 "C. The intensity of the lamp was 680 

w/m2, and 7.0 hours of irradiation with the artificial light was reported to be equivalent 

to I solar day in late June in Phoenix, Arizona. ['4~]-~yrasulfotole dcreased from an 

average of 104.2% of the applied at time 0 to 87.2% in the irradiated samples and 89.9% 

in the dark controls at study termination (9 days posttreatment). Concentrations were 

variable and were affected by overall recoveries of 14c-residues; [14~]-pyrasulfotole 

comprised 97.9% of the recovered at time 0 and 90.0% and 93.6% in the irradiated and 

dark controls, respectively, at 9 days posttreatment. No major transformation products 

were isolated from either the irradiated or dark control soils. No minor transformation 

products, which averaged 11 .O% of the applied, were identified in either the irradiated or 

dark control soils. Based on first order linear regression analysis, pyrasulfotole dissipated 

with half-lives of 32.5 days in the irradiated samples (continuous irradiation) and 64.2 

days in the dark controls. The half-lives are of uncertain value because they are 

extrapolated well beyond the duration of the study, between replicate variability at some 

intervals is ca. 5% of the applied, and the calculations are based on the assumption that 
degradation follows a linear pattern. The phototransformation half-life for 

pyrasulfotole, was 66 days based on the continuous irradiation used in the study. The 

study author stated that 7.0 hours of continuous irradiation with the artificial light was 

equivalent to 1 day of natural sunlight in Phoenix, Arizona (33.26" N latitude). 

Therefore, the environmental phototransformation half-life is expected to be ca. 227 

days in Phoenix, AZ. 

Metabolism 

Aerobic Soil Metabolism 

In an acceptable aerobic soil metabolism study (MRID 46801709), [I4c]- 

pyrasulfotole dissipated in a Goldsboro loamy sand soil (pH 5.6-6.2, organic carbon 

1.2%) from North Carolina following a biphasic pattern decreasing quickly from 96.4- 

97.5% of the applied at day 0 posttreatment to 53.8-54.8% at 4 days and was 40.0-40.7% 

at 7 days, then dissipation significantly slowed with [~4~]-pyrasulfotole comprising 20.2- 

22.8% at study termination. The log-linear half-life was 240 days (r2 = 0.4428) and the 

nonlinear half-life was 69 days (r2 = 0.441). Based on a 2-compartment, 4-parameter 

exponential model (DFOP) the DTS0 and DTgO estimates were 5.8 and 749 days, 

respectively (2 = 0.977). The observed DTS0 and DT90 values were 4-7 days and >358 

days, respectively. Soil samples were extracted using an Accelerated Solvent Extraction 

(ASE) system, which conducted two-phase ["mild" (40°C, 100 bar) and "aggravated" 

(1OO0C, 100 bar) conditions], automated, multi-step extractions with acetonitri1e:water 

(2: 1, v:v) as the extraction solvent. 

2-Methylsulfonyl-4-trifluoromethylbenzoic acid (AE B 197555) was a major 

transformation product in phenyl-label treated soil detected at a maximum 12.2% of the 

applied at 7 days posttreatment and was 4.2% at study termination. No minor 

transformation products were identified for either label. Unextractable I4c-residues 

increased from 1.7-1.9% at day 0 to maximums of 49.7-50.1% at 100-120 days and were 

43.2-44.8% at 358 days. At study termination, volatilized I4c02 totaled 17.3%-18.6% of 

the applied. 

Under sterile (autoclaved soil, both labels) conditions, parent pyrasulfotole 

comprised 94.8-95.4% of the applied at 120 days (final interval), with AE B197555 in 

phenyl-label treated soil detected at 13.2% at any interval. At study termination, 

extractable and unextractable 14~-residues were 95.6-99.3% and 2.7-3.5% of the applied, 

respectively, with volatilized I4co2 and volatile I4c-organic compounds S0.2%. 

In an acceptable aerobic soil metabolism study (MRID 46801710), [I4c]- 

pyrasulfotole dissipated in a LaDelle silt loam soil (pH 7.0-7.3, organic carbon 4.7%) 

from North Dakota following a biphasic pattern with a steady decline during the initial 2 

months posttreatment, decreasing from 94.3-97.1 % of the applied at day 0 to 47.2-50.0% 

at 65 days, then dissipation slowed with ['4~]-pyrasulfotole comprising 22.0-24.9% at 

study termination. The log-linear half-life for both radiolabels was 161 days (r2 = 

0.8227) and the nonlinear half-life was 95 days (r2 = 0.9144). The DTS0 and DT90 

estimates based on a 2-compartment, 4-paramter exponential model (DFOP) were 63 and 

1424 days, respectively (r2 = 0.998). The observed DTS0 and DTg0 and values were 50- 
65 days and >358 days, respectively. Soil samples were extracted using an Accelerated 

Solvent Extraction (ASE) system, which conducted two-phase ["mild" (40°C, 100 bar) 

and "aggravated" (I OO°C, 100 bar) conditions], automated, multi-step extractions with 

acetonitri1e:water (2: 1, v:v) as the extraction solvent. 

2-Methylsulfonyl-4-trifluoromethylbenzoic acid (AE B 197555) was a minor 

transformation product in phenyl-label treated soil detected at a maximum 3.8% of the 

a plied; no other minor or major products were identified for either label. Unextractable IP C-residues increased from 0.4-1.1 % at day 0 to maximums of 3 1.3-35.2% at 155-190 

days and were 30.1-30.7% at 358 days. At study termination, volatilized I4co2 totaled 

33.5-40.5% of the applied. 

Under sterile (autoclaved soil, both labels) conditions, parent pyrasulfotole 

comprised 93.6-94.2% of the applied at 120 days (final interval), with AE B197555 in 

phenyl-label treated soil detected at a maximum 3.7% at study termination. At 120 days, 

extractable and unextractable 14c-residues were 93.6-97.9% and 3.8-5.2% of the applied, 

respectively, with volatilized I4c02 and volatile '4~-organicompounds 50.4%. 

In a supplemental aerobic soil metabolism study (MRID 4681701 I), phenyllabeled pyrasulfotole dissipated in a sandy loam soil (pH 5.9-6.6, organic carbon 1.4%) 

from Germany from a mean 100.0% of the applied at day 0 to 48.0% at 29 days and was 

19.0% at 120 days. Pyrazole-labeled pyrasulfotole reached the observed DT50 somewhat 

faster decreasing from 98.4% at day 0 to 48.9% at 21 days and was 17.3% at study 

termination. The log-linear half-life for both radiolabels was 48 days (r2 = 0.9127) and 

the nonlinear half-life was 32.4 days (r2 = 0.9503). The DTS0 and DT90 estimates based 

on a 2-compartment, 4-parameter exponential model (DFOP) were 23 and 208 days, 

respectively (r2 = 0.990). The observed DTS0 and DT90 values were between 14 and 29 

and >I20 days, respectively. Soil samples were extracted using an Accelerated Solvent 

Extraction (ASE) system, which conducted two-phase ["mild" (40°C, 103 bar) and 

"aggravated" (lOO°C, 103 bar) conditions], automated, multi-step extractions with 

acetonitri1e:water (2: 1, v:v) as the extraction solvent. 

2-Methylsulfonyl-4-trifluoromethylbenzoic acid (AE B197555) was a minor 

transformation product in phenyl-label treated soil detected at a maximum 8.9 f 0.4% of 

the applied; no other minor or major products were identified for either label. 

Unextractable I4c-residues increased from 2.1-2.7% at day 0 to 60.1-62.1% at study 

termination (120 days). At study termination, volatilized I4co2 comprised total means of 

16.3- 18.0% of the applied, while volatile 14~-organic compounds were 50.1 % at all 

intervals. 

Table B.a. summarizes the various modeled used to describe the degradation 

kinetics in the aerobic soil metabolism studies. 
Anaerobic Soil Metabolism 

Table B.a. Summary of Models Used to Fit Degradation Data in Aerobic Soil Metabolism 

Studies. 

In an acceptable anaerobic soil metabolism study (MRID 46801 712), [l4c]- 

pyrasulftole-residues partitioned between the soil and water layer with mean (n = 2) 

distribution ratios (water:soil) of 1 :22-28 immediately after flooding (30 days 

posttreatment), decreasing to 1:5 after 33 days (63 days posttreatment) and were 1 :7-11 at 

study termination (1 50 days posttreatment). The dissipation rate of ['4~]-pyrasulfotole 

significantly slowed with the conversion to anaerobic conditions. ['4~]-~yrasulfotole 

comprised means of 93.5-97.3% of the applied in the soil at day 0 posttreatment, then at 

day 0 post-flooding (30 days posttreatment) was detected at 66.0-68.4% in the total 

system and was 62.2-64.1 % at 120 days post-flooding (1 50 days posttreatment). In the 

water layer, [14~]-pyrasulfotole increased from means of 2.4-3.1% at day 0 post-flooding 

(30 days posttreatment) to 11.7-14.2% at 33 days (63 days posttreatment) and was 7.2- 

7.7% at study termination. In the soil, ['4~]-pyrasulfotole decreased from means of 93.5- 

97.3% at day 0 posttreatment to 62.9-66.0% at day 0 post-flooding (30 days 

posttreatment) and was 53.3-56.5% at 90-120 days post-flooding (120-150 days 

posttreatment). Observed DTS0 values for yrasulfotole in the total system were >I20 

days. Calculated dissipation half-lives for [ ,B C]-pyrasulfotole in the total system could 

not be determined due to insufficient dissipation post-flooding. Since the degradation 

rate could not be quantified, pyrasulfotole is assumed to be stable for the purposes of risk 

assessment. 

Model Half-life (d) 

Loamy sand, North Carolina (MRID 46801709) 

Model equation 

Log-linear 

Nonlinear 

DFOP 

Observed 

DT50190 

r2 

240 

68.6 

-- 

-- 

Silt loam, North Dakota (MRID 46801710) 

DTSO (d) 

y = -0.0029~ + 3.7590 

y = 58.6*exp(-0.0101*x) 

y = 69.0*exp(-0.24*x) + 33.1 *exp(-0.00 16*x) 

-- 

Log-linear 

Nonlinear 

DFOP 

Observed 

DT50190 

DTBO (4 

0.443 

0.441 

0.977 

-- 

161 

95.0 

-- 

-- 

Sandy loam, Germany (MRID 46810711) 

-- 

-- 

5.8 

4-7 

y = -0.0043~ + 4.2958 

y= 87.2*exp(-0.0073*x) 

y= 66.6*exp(-0.019*x)+31.2*exp(-0.0008*x) 

-- 

Log-linear 

Nonlinear 

DFOP 

Observed 

DT50/90 

-- 

-- 

747 

>358 

0.823 

0.914 

0.998 

-- 

47.6 

32.4 

-- 

-- 

-- 

63 

50-65 

y = -0.01456 + 4.3854 

y = 9 1.4*exp(-0.0214*x) 

y = 58.5*exp(-0.054*x)+37.7*exp(-0.0064*x) 

-- 

-- 

1424 

>358 

0.913 

0.950 

0.990 

-- 

-- 

23 

14-29 

-- 

208 

>I20 
2-Methylsulfonyl-4-trifluoromethylbenzoic acid (AE B 197555) was the sole 

transformation product detected at maximum means of 5.1 % (1 5 days post-flooding), 

7.7% (day 0 post-flood) and 9.9% (1 5 and 61 days post-flood) of the applied in the water, 

soil and total system, respectively, of phenyl-label [14~]-pyrasulfotole treated soil and 

was 4.1 %, 5.1 % and 9.2%, respectively, at study termination. 

Phenyl-label unextractable 14c-residues increased from 0.8% at day 0 to 22.5% at 

study termination. Pyrazole-label unextractable 14C-residues increased from 2.0% at day 

0 to 24.9% at study termination. Maximum mean levels of volatilized I4c02 (identity not 

confirmed) detected were 2.6% and 6.6% of the applied for the phenyl- and pyrazolelabel treated soils, respectively, while volatile 14c-organic compounds were SO. 1 % (both 

labels) at all sampling intervals. 

Aerobic Aquatic Metabolism 

In an acceptable aerobic aquatic metabolism study (MRID 4680 17 13), the 

biotransformation of pyrasulfotole was studied in a pond water-sandy loam sediment 

(water pH 4.8, sediment pH 4.5-5.4, organic carbon 4.1%) from North Carolina and a 

pond water-silty clay sediment (water pH 7.5, sediment pH 6.9-7.5, organic carbon 

0.81 %) from Kansas for 13 1-1 32 days under aerobic conditions. Sediment samples were 

extracted two to three times with acetonitri1e:water [4: 1 (v:v) for 0- and 1 1-day sandy 

loam sediments; 9: 1 (v:v) for all other sediment samples] via shaking, then further 

extracted with the acetonitri1e:water solvent using an Accelerated Solvent Extraction 

(ASE) system (2 cycles, 80°C, 1,500 psi). 

In sandv loam svstems (both labels), following application of [14c]- 

pyrasulfotole to the water layer, I4c-residues partitioned from the water layer to the 

sediment with average (n = 2) distribution ratios (water:sediment) of ca. 100: 1 at day 0, 

2: 1 at 1 1-55 days, 1 :4 at 81 days and were 1 :>lo thereafter. [14~]-~yrasulfotole in the 

total system decreased from a mean 97.6% of the ap lied at day 0 to 44.5% at 81 days P, and was 16.3-1 8.2% thereafter. In the water layer, [ C]-pyrasulfotole decreased from a 

mean 97.6% at day 0 to 61.8-68.3% at 11-55 days, 22.9% at 81 days and was 5.2-5.5% 

thereafter. In the sediment, [14~]-pyrasulfotole increased from a mean 0.9% at day to 

25.0% at 26 days, then decreased to 1 1 .l-12.7% at 109-1 32 days. Linear half-life for 

pyrasulfotole in the total system was 48 days and nonlinear half-life was 69 days. 

Observed DTS0 values were 55-1 09 days in the total system. However, these fitted 

transformation models do not adequately fit the observed dissipation pattern of parent 

residues. Extractable 14c-residues in the sediment increased from a mean 0.9% of the 

applied at day 0 to a maximum 25.1 % at 26 days, then decreased to 1 1.1 - 13.1 % at 109- 

132 days. Unextractable 14c-residues were detected at means of 8.1 - 15.0% at 1 1-55 

days, then sharply increased to 50.7% at 81 days and were 72.6% at study termination. 

Pyrasulfotole does not appear to be transforming in this sandy loam system, but 

rather rapidly partitions from the water to an unextractable sediment-bound phase 

between Days 55 - 81. Pyrasulfotole is therefore considered to be stable under 

conditions of this aerobic aquatic system for the purposes of risk assessment. 

In siltv clav loam svstems (both labels), following application of [I4c]- 

pyrasulfotole to the water layer, I4c-residues partitioned from the water layer to the 

sediment with average (n = 2) distribution ratios (water:sediment) of ca. 100: 1 at day 0, 
3: 1 at 2 1 days and were 2: 1 thereafter. ['4~]-~yrasulfotole dissipated slowly in the total 

system decreasing from a mean 101.4% of the applied at day 0 to 82.3-87.8% at 104-13 1 

days. In the water layer, [14~]-pyrasulfotole decreased from a mean 100.9% of the 

applied at day 0 to 63.9% at study termination, while increasing in the sediment from 

0.5% to 23.9% at the same respective intervals. Observed DTS0 values were >13 1 days 

in the water, sediment and total system. Lineadnonlinear half-lives for pyrasulfotole in 

the sediment and total system were not determined because levels of parent in the 

sediment were still increasing at study termination, and there was insufficient dissipation 

of parent in the total system. Hence there is no evidence of degradation for pyrasulfotole 

in this aerobic aquatic system. For the purposes of risk assessment it is considered stable. 

Extractable I4c-residues in the sediment increased from a mean 1 .O% of the applied at 

day 0 to 24.4% at 131 days. Unextractable 14c-residues increased from a mean 0.5% at 

day 0 to 13.1 % at 104 days and were 10.6% at study termination. 

Anaerobic Aquatic Metabolism 

In an acceptable study (MRID 46801 7 14), the biotransformation of pheny1-Ul"~-labeled pyrasulfotole was studied in a pond water-silty clay sediment (water pH 7.5, 

dissolved organic carbon 11.7 mg/L; sediment pH 6.6-7.0, organic carbon 1 .I%) systems 

from Kansas for 365 days under anaerobic (static, nitrogen atmosphere) conditions in 

darkness at 20 f 1°C. Following application of ['4~]-pyrasulfotole to the water-sediment 

systems, 14c-residues partitioned from the water layer to the sediment with average (n = 

2) distribution ratios (water:sediment) of 100: 1 at day 0,4: 1 at 3 days, 2: 1 at 10 days and 

were 1 : 1 thereafter. ['4~]-~yrasulfotole dissipated slowly in the total system decreasing 

fiom a mean 99.2% of the applied at day 0 to 65.1% at 31 days and was 60.4%-65.6% 

thereafter. In the water layer, '4~-pyrasulfotole decreased from a mean 99.2% at day 0 to 

49.7% at 31 days and was 38.3-40.0% at 183-365 days. In the sediment, I4cpyrasulfotole increased to a mean 25.5% at study termination. 

Levels of ['4~]-pyrasulfotole in the sediment were still increasing at study 

termination; consequently, calculated half-lives could not be determined. Observed 

DTS0 values of pyrasulfotole were between 22 and 3 1 days in the water layer and greater 

than 365 days in the sediment and total system. Non-first order DT50 and DT90 

estimates for the total system were estimated at 6000 and 46000 days, respectively using 

a multi-compartment non-linear regression model (r2 = 0.95). Pyrasulfotole is 

considered stable in the whole system under these anaerobic aquatic conditions for 

the purposes of this risk assessment. 

Extractable and unextractable sediment I4c-residues increased to maximum 

means of 25.5% and 33.9% of applied, respectively, at 365 days. The maximum level of 

volatilized I4c02 detected at any sampling interval was 2.8% of the applied, with volatile 

I4c-organic compounds less than 0.1 %. 

In an acceptable study (MRID 46801 7 15), the biotransformation of pyrazole-3- 

I4c-labeled pyrasulfotole was studied in a pond water-silty clay sediment (water pH 7.5, 

dissolved organic carbon 1 1.7 mg/L; sediment pH 7.0, organic carbon 1.1 %) systems 

fiom Kansas for 365 days under anaerobic (static, nitrogen atmosphere) conditions in 

darkness at 20 f 1 OC. Following application of [14~]-pyrasulfotole tothe water-sediment 
systems, 14c-residues partitioned from the water layer to the sediment with average (n = 

2) distribution ratios (water:sediment) of 100: 1 at day 0,4: 1 at 3 days, 1 : 1 at 14- 184 days 

and were 1 :2 thereafter. ['4~]-~yrasulfotole dissipated slowly in the total system 

decreasing from a mean 100.0% of the a plied at day 0 to 54.9% at 275 days and was P, 59.7% at 365 days. In the water layer, [ C]-pyrasulfotole decreased fiom a mean 

100.0% at day 0 to 49.9% at 17 days and was 37.3% at study termination. In the 

sediment, ['4~]-pyrasulfotole increased to a mean 22.7% at 63 days and was 19.1-22.9% 

thereafter. 

Calculated linear and nonlinear half-lives for pyrasulfotole in the water layer and 

total system are of limited use given the low correlation coefficient values (r2 = <0.45), 

and the half-lives for pyrasulfotole in the total system were extrapolated significantly 

beyond the final sampling interval. Since concentrations of [14~]-pyrasulfotole inthe 

sediment remained at steady levels from 63 days posttreatment through study 

termination, calculated half-lives could not be determined. Observed DTso values of 

pyrasulfotole were between 14 and 28 days in the water layer and greater than 365 days 

in the sediment and total system. Non-first order DT50 and DT90 estimates for the total 

system were estimated at 722 and 4745 days, respectively using a multi-compartment 

non-linear regression model (r2 = 0.95). For the purposes of risk assessment, 

pyrasulfotole is considered stable in the whole system under these anaerobic aquatic 

conditions. 

Extractable sediment I4c-residues increased to a maximum mean 22.9% of 

applied at 120 days and were 22.4% at 365 days. Unextractable sediment I4c-residues 

increased to a maximum mean 36.4% at study termination. Volatilized I4c02 totaled a 

mean 1.9% of the applied at study termination, with volatile '4~-organicompounds 

10.1 % at any interval. 

Mobility and Persistence 

Batch Equilibrium 

In an acceptable study (MRID 46801 703), the adsorptiontdesorption 

characteristics of pyrasulfotole were studied in definitive experiments using three US 

soils: a HCB silt loam [ pH 7.7, organic carbon 4.7%], a Pikeville loamy sand [ pH 6.4, 

organic carbon 1.2%], and a Carlyle silt loam [pH 5.2, organic carbon IS%]; two 

German soils: a clay loam [CL6S, pH 7.5, organic carbon 1.7%] and a sandy loam 

CSL2.3, pH 6.7, organic carbon 1.1 %I; and a German sediment, Nidda sandy loam [pH 

5.8, organic carbon 4.6%], in a batch equilibrium experiment. After 24 hours of 

equilibration, 55.7-63.3%, 60.3-71.0%, 26.4-32.3%, 30.1 -35.2%, 43.9-52.2%, and 50.4- 

73.5% of the applied [14~]-pyrasulfotole was adsorbed to the HCB silt loam, Pikeville 

loamy sand, CL6S clay loam, SL2.3 sandy loam, and Carlyle silt loam soils, and the 

Nidda sandy loam sediment, respectively (reviewer-calculated). Adsorption & values 

averaged 1.32, 1.77, 0.367,0.47,4.25, and 32.9 for the HCB silt loam, Pikeville loamy 

sand, CL6S clay loam, SL2.3 sandy loam, and Carlyle silt loam soils, and the Nidda 

sandy loam sediment, respectively; corresponding adsorption &, values averaged 28.1, 

148,21.6,42.7, 283, and 71 5. Freundlich adsorption KF values were 0.980, 1.20,0.341, 

0.386, 3.20, and 15.9 for the HCB silt loam, Pikeville loamy sand, CL6S clay loam, 
SL2.3 sandy loam, Carlyle silt loam soils, and the Nidda sandy loam sediment, 

respectively; corresponding Freundlich adsorption KF~~ values were 20.8, 100,20.0, 35.1, 

213, and 345. At the end of the desorption phase, 55.0%, 49.7%, 70.4% 69.0% 65.6%, 

and 61 .l% of the applied ['4~]pyrasulfotole desorbed from the HCB silt loam, Pikeville 

loamy sand, CL6S clay loam, SL2.3 sandy loam, and Carlyle silt loam soils, and the 

Nidda sandy loam sediment, respectively. Desorption Kd values averaged 2.26, 3.67, 

0.923, 1.5 1, 10.4, and 56.6 for the HCB silt loam, Pikeville loamy sand, CL6S clay loam, 

SL2.3 sandy loam, and Carlyle silt loam soils, and the Nidda sandy loam sediment, 

respectively; corresponding adsorption &, values averaged 48.2, 306, 54.3, 137,696, 

and 1230. Freundlich desorption KF values were 1.37,2.30, 0.678, 1.13, 8.46, and 30.9 

for the HCB silt loam, Pikeville loamy sand, CL6S clay loam, SL2.3 sandy loam, and 

Carlyle silt loam soils, and the Nidda sandy loam sediment, respectively; corresponding 

Freundlich desorption KFoc values were 29.2, 192,40, 103, 564, and 672. 

Terrestrial Field Dissipation 

In an acceptable study (MRID 46801 7 16), soil dissipation/accumulation of 

pyrasulfotole under US field conditions was conducted in three replicate bare plots and 

three replicate cropped plots (wheat) of Farnum loam soil in Kansas. In the bare test plot, 

the measured zero-time recovery of pyrasulfotole in the 0- 15 cm soil layer was 19.80 ppb 

or 63.9% of the theoretical based on the target application rate (reviewer-calculated based 

on a theoretical day-0 recovery of 3 1 pglkg). Pyrasulfotole decreased to 1 1.20 ppb by 7 

days, 6.54 ppb by 14 days, 1.36 ppb by 58 days, and was last detected above the LOQ at 

0.69 ppb at 257 days post-treatment. Pyrasulfotole was detected at levels below the LOQ 

in the 15-30 cm soil depth, and was not detected below 30 cm. The major transformation 

product AE B197555 was detected in the 0-1 5 cm soil depth at a maximum concentration 

of 6.15 ppb at 4 days (which is equivalent to 8.3 1 ppb parent equivalents or 26.8% of the 

theoretical applied pyrasulfotole based on the target application rate), then decreased to 

3.25 ppb by 14 days, was below the LOQ by 58 days, and was not detected by 257 days 

post-treatment. AE B 197555 was not detected below the 0-1 5 cm soil depth at any 

sampling intervals. 

Under field conditions in the bare test plot, pyrasulfotole had a calculated half-life 

DT50 and DT90 values for pyrasulfotole in the whole soil column using a double first 

order regression model were 8.9 and 45 days, respectively (r2 = 0.97). Calculated DTSO 

and DTgO values for the strongly bi-phasic dissipation pattern of AE B197555 residues in 

the whole soil column were 17 and 45 days following initial application, respectively (r2 

= 0.87). In the bare test plot, residue carryover (i.e., percentage of the total amount of 

parent equivalent material in the whole soil column relative to Day 0 concentrations) was 

4.7% at the beginning of the following growing season (i.e., at 257 days post treatment), 

and 1.2% at the end of the study (i.e., 526 days post treatment). 

In an acceptable study (MRID 46801 71 7), soil dissipation/accumulation of 

pyrasulfotole under US field conditions was conducted in three replicate bare plots and 

three replicate cropped plots (wheat) of clay loam/loam soil in North Dakota. In the 

test plot, the measured zero-time recovery of pyrasulfotole in the 0-1 5 cm soil layer was 
24.4 ppb or 7 1.8% of the theoretical based on the target application rate (calculated based 

on a theoretical day-0 recovery of 34 pglkg). Pyrasulfotole decreased to 1 1.9 ppb by 7 

days, 4.0 ppb by 27 days, and was last detected above the LOQ at 0.5 ppb at 377 days 

posttreatment. Pyrasulfotole was not detected above the LOQ in soil below the 0-1 5 cm 

soil depth. The major transformation product AE B197555 was initially detected in the 

0-1 5 cm soil depth at 1.2 ppb at day 0, increased to a maximum of 13.5 ppb by 7 days 

(which is equivalent to 18.2 ppb parent equivalents or 53.6% of the theoretical applied 

pyrasulfotole based on the target application rate), then decreased to 5.7 ppb by 27 days, 

1 .O ppb by 3 17 days, and was below the LOQ by 377 days posttreatment. AE B197555 

was not detected below the 0-1 5 cm soil depth. 

Under field conditions in the bare test plot, pyrasulfotole had calculated DTS0 and 

DT90 values for pyrasulfotole in the whole soil column were 6 and 44 days, respectively 

(two compartment non-linear regression model; r2 = 0.96). The calculated DTSO and 

DTgO values for AE I3197555 in the whole soil column were 25 and 227 days, 

respectively (two-compartment, non-linear regression model; r2 = 0.8 l).Carryover of total 

residues in the soil column was 7.7 and 1.8% of the applied pyrasulfotole at the 

beginning of the following growing season (i.e. day 3 17) and at the end of the study 

period (i.e. day 498), respectively, based on observed Day 0 concentrations. 

In an acceptable study (MRID 46801 71 8), soil dissipation/accumulation of 

pyrasulfotole under US field conditions was conducted in three replicate bare plots and 

three replicate cropped plots (wheat) of sandy loam soil in Washington. In the bare test 

plot, the measured zero-time recovery of pyrasulfotole in the 0-15 cm soil layer was 

27.18 ppb or 109% of the theoretical based on the target application rate (calculated 

based on a theoretical day-0 recovery of 25 &kg). Pyrasulfotole decreased to 17.5 1 - 

18.59 ppb by 1-3 days, 12.35 ppb by 7 days, was last detected above the LOQ at 1.10 ppb 

at 28 days, and was not detected following 175 days posttreatment. Pyrasulfotole moved 

into deeper soil layers over time, reaching the 45-60 cm layer at 28 days, the 75-90 cm 

layer at 58 days, and the 105-120 cm layer by 175 days. Pyrasulfotole was detected in the 

15-30, 30-45,45-60,60-75, and 75-90 cm soil layers at maximum concentrations of 3.26 

ppb (28 days), 1.84 ppb (28 days), 1.99 ppb (175 days), 1.24 ppb (58 days), and 0.57 ppb 

(58 days), respectively; residues were detected below the LOQ in the 90-1 05 and 105-120 

cm soil layers. The major transformation product AE B197555 was detected in the 0-1 5 

cm soil depth at a maximum of 3.86 ppb at 7 days (which is equivalent to 5.21 ppb parent 

equivalents or 20.8% of the theoretical applied pyrasulfotole based on the target 

application rate), then decreased to below the LOQ by 28-58 days, and was not detected 

by 120 days posttreatment. AE B197.555 was detected in the 15-30 cm soil depth at a 

maximum concentration of 0.94 ppb at 14 days, in the 30-45 cm soil depth at a maximum 

of 1.59 ppb at 28 days, and in the 45-60 cm soil depth at a maximum of 0.57 ppb at 28 

days. AE B197555 was not detected above the LOQ in soil below the 45-60 cm depth; 

however, residues were detected below the LOQ to 120 cm, the maximum depth 

analyzed. 

Under field conditions in the bare test plot, pyrasulfotole had calculated DTso and 

DT9o values for pyrasulfotole in the whole soil column were 6 and 21 3 days, respectively 

(two compartment non-linear regression model; r2 = 0.94). The calculated half-life value 
for AE B197555 residues in the whole soil column was 42.0 days (first order regression; 

r2 = 0.94), or an estimated DTso of 49 days following initial application. Carryover of 

total residues in the soil column was 1 1.1 and 3.3% of the applied pyrasulfotole at the 

beginning of the following growing season (i.e. day 269) and at the end of the study 

period (i.e. day 526), respectively, based on observed Day 0 concentrations. 

In an acceptable study (MRID 46801 71 9), soil dissipation~accumulation of 

pyrasulfotole under Canadian field conditions was conducted in four replicate bare plots 

in Saskatchewan (Site I), Manitoba (Site 2), and Ontario (Site 3) on clay loam soils. 

At Site 1 (Saskatchewan), the measured zero-time recovery of pyrasulfotole in the 

0-7.5 cm soil layer was 65.5 ppb or 58.0% of the theoretical based on the target 

application rate (calculated based on a theoretical day-0 recovery of 1 13 &kg). 

Pyrasulfotole decreased to 32.8-37.0 ppb by 7-14 days, 20.2-20.8 ppb by 21-30 days, 

6.42 ppb by 120 days, and was 1.52-2.13 ppb fiom 402 to 449 days posttreatment. 

Pyrasulfotole was detected at 52.83 ppb in the 7.5-1 5 cm soil depth, 51.46 ppb in the 15- 

30 cm depth, and 50.65 ppb in the 30-45 cm depth, and was detected only below the 

LOQ in the 45-60 cm and 60-75 cm depths. The major transformation product AE 

B197555 was detected in the 0-7.5 cm soil depth at a maximum of 36.9 ppb at 14 days 

(which is equivalent to 49.8 ppb parent equivalents, or 67.3% of the total parent 

equivalents in the soil column at Day 0 after application), ranged from 32.1 to 34.9 ppb 

from 21 to 56 days, then decreased to 8.63 ppb by 120 days, and was 0.90 ppb at 449 

days posttreatment. AE B197555 was detected in the 7.5-1 5 cm soil depth at a maximum 

of 4.63 ppb at 120 days and in the 15-30 cm depth at a maximum of 2.60 ppb at 343 days. 

AE B197555 was not detected above the LOQ in soil below the 15-30 cm depth. 

At Site 2 (Manitoba), the measured zero-time recovery of pyrasulfotole in the 0- 

15 cm soil layer was 1 12.99 ppb or 90.4% of the theoretical based on the target 

application rate (calculated based on a theoretical day-0 recovery of 125 pglkg). 

Pyrasulfotole decreased to 44.8-56.2 ppb from 7 to 61 days, 16.9 ppb by 121 days, 8.34 

ppb by 349 days, and was 4.60 ppb at 462 days posttreatment. Pyrasulfotole was detected 

at 57.53 ppb in the 7.5-1 5 cm soil depth, 53.5 1 ppb in the 15-30 cm depth, and 11.14 ppb 

in the 30-45 cm depth, and was only detected below the LOQ in the 45-60 cm depth. The 

major transformation product AE B197555 was detected in the 0-7.5 cm soil depth at a 

maximum of 26.7 ppb at 29 days (which is equivalent to 36.1 ppb parent equivalents, or 

29.0% of the total parent equivalents in the soil column at Day 0 after application), 

decreased to 16.1 ppb by 6 1 days, and ranged from 1.17 to 1.80 ppb fiom 12 1 to 462 days 

posttreatment. AE B 197555 was detected in the 7.5-1 5 cm soil depth at a maximum of 

3.40 ppb at 7 days and was not detected above the LOQ in soil below the 7.5-15 cm 

depth, but was detected at levels below the LOQ in all soil depths analyzed (0-75 cm) at 

462 days posttreatment. 

At Site 3 (Ontario), the measured zero-time recovery of pyrasulfotole in the 0-1 5 

cm soil layer was 58.1 ppb or 63.1% of the theoretical based on the target application rate 

(calculated based on a theoretical day-0 recovery of 92 @kg). Pyrasulfotole decreased to 

32.4 ppb by 14 days, 20.4 ppb by 30 days, 4.91 ppb by 139 days, and was 0.75 ppb at 458 

days posttreatment. Pyrasulfotole was detected at 14.10 ppb in the 7.5-1 5 cm soil depth 

and was detected below the LOQ in the 15-30, 30-45,45-60, and 60-75 cm depths. The 
major transformation product AE B197555 was detected in the 0-7.5 cm soil depth at a 

maximum of 27.8 ppb at 14 days (which is equivalent to 37.6 ppb parent equivalents, or 

56.7% of the total parent equivalents in the soil column at Day 0 after application), then 

decreased to 15.7 ppb by 30 days, 5.20 ppb by 56 days, and was last detected above the 

LOQ at 0.85 ppb at 350 days posttreatment. AE B197555 was detected in the 7.5-15 cm 

soil depth at a maximum of 2.40 ppb at 7 days and in the 15-30 cm depth at a maximum 

of 1.01 ppb at 30 days, and was detected at levels below the LOQ in the 30-45,45-60, 

and 60-75 cm depths. 

Under field conditions at Site 1 (Saskatchewan), pyrasulfotole had a calculated 

DT50 and DT90 values for whole-soil column pyrasulfotole residues were 10 and 260 

days, respectively (2 compartment non-linear model, $ = 0.86). The calculated half-life 

value for AE B 197555 residues in the whole soil column was 121.6 days (? = 0.86), or 

an estimated DTS0 of 136 days following initial application. 

Under field conditions at Site 2 (Manitoba), pyrasulfotole had a calculated DT50 

and DTqO values for whole-soil column pyrasulfotole residues were 9.2 and 53 1 days, 

respectively (2 compartment non-linear model, r2 = 0.89). The calculated half-life value 

for AE B197555 residues in the whole soil column was 35.0 days (r2 = 0.82), or an 

estimated DTso of 64 days following initial application. 

Under field conditions at Site 3 (Ontario), pyrasulfotole had a calculated DTso and 

DT90 values for whole-soil column pyrasulfotole residues were 1 8 and 178 days, 

respectively (2 compartment non-linear model, r2 = 0.96). The calculated half-life value 

for AE B197555 residues in the whole soil column was 26.8 days (r2 = 0.94), or an 

estimated DTSo of 41 days following initial application. 

Carryover of residues at the start of the following growing season (i.e., at 343-350 

days post treatment), was 37.2%, 18.9% and 8.9% of the applied pyrasulfotole for sites in 

Saskatchewan, Manitoba and Ontario respectively (the majority of residues were detected 

as parent at all sites; total parent-equivalent residues in the soil column were compared to 

observed levels at Day 0). By the end of the study period (i.e., 449-462 days post 

treatment), 13.7, 16.2 and 2.0% of the applied pyrasulfotole was present in the 

Saskatchewan, Manitoba and Ontario sites, respectively. 
APPENDIX C: PRZMIEXAMS Output Data from the ND Wheat, OR Wheat, and 

TX Wheat Scenarios 

ND Wheat 

stored as NDwheat.out 

Chemical: pyrasulfotole 

PRZM environment: NDwheatC.txt modified Satday, 12 October 2002 at 15: 15:08 

EXAMS environment: pond298.e~~ modified Thuday, 29 August 2002 at 15:33:30 

Mettile: w14914.dvf modified Wedday, 3 July 2002 at 08:05:52 

Water segment concentrations (ppb) 

Year 

1961 

1962 

1963 

1964 

1965 

1966 

1967 

1968 

1969 

1970 

1971 

1972 

1973 

1974 

1975 

1976 

1977 

1978 

1979 

1980 

198 1 

1982 

1983 

1984 

1985 

1986 

1987 

1988 

1989 

1990 

Peak 

0.1961 

0.8606 

1.138 

1.596 

1.703 

1.839 

2.005 

2.163 

2.47 

2.719 

3.035 

3.182 

3.317 

3.552 

4.168 

4.215 

4.524 

4.916 

5.106 

5.238 

5.79 

5.886 

6.088 

6.615 

6.935 

7.2 14 

7.472 

7.762 

7.992 

8.339 

Sorted results 

Prob. Peak 96 hr 

0.0322580645 161 29 

0.0645 161 29032258 1 

0.0967741935483871 

0.129032258064516 

0.16 1290322580645 

0.193548387096774 

0.22580645 16 12903 

0.2580645 16129032 

0.290322580645 161 

0.32258064516129 5.79 

0.35483870967741 9 

0.3870967741 93548 

0.4 19354838709677 

0.45 161 2903225806 

0.48387096774 1936 

21 Day 

0.1948 

0.8538 

1.132 

1.586 

1.7 

1.837 

2.001 

2.161 

2.466 

2.715 

3.029 

3.18 

3.316 

3.549 

4.157 

4.2 12 

4.519 

4.907 

5.103 

5.237 

5.778 

5.884 

6.085 

6.603 

6.93 1 

7.209 

7.47 

7.758 

7.99 

8.333 

21 Day 

8.339 

7.992 

7.762 

7.472 

7.214 

6.935 

6.615 

6.088 

5.886 

5.788 

5.238 

5.106 

4.916 

4.524 

4.215 

60 Day 

0.1927 

0.8487 

1.128 

1.572 

1.699 

1.835 

1.996 

2.16 

2.461 

2.708 

3.025 

3.179 

3.316 

3.546 

4.141 

4.208 

4.5 13 

4.896 

5.099 

5.237 

5.764 

5.881 

6.082 

6.587 

6.926 

7.206 

7.466 

7.754 

7.988 

8.325 

60 Day 

8.338 

7.991 

7.761 

7.472 

7.2 13 

6.934 

6.6 12 

6.088 

5.886 

5.778 

5.238 

5.105 

4.915 

4.523 

4.215 

90 Day 

0.1915 

0.8427 

1.126 

1.57 

1.698 

1.835 

1.994 

2.159 

2.458 

2.705 

3.02 1 

3.178 

3.315 

3.544 

4.132 

4.206 

4.509 

4.89 

5.097 

5.236 

5.756 

5.879 

6.08 

6.578 

6.923 

7.203 

7.464 

7.75 1 

7.987 

8.322 

90 Day 

8.333 

7.99 

7.758 

7.47 

7.209 

6.93 1 

6.603 

6.085 

5.884 

5.764 

5.237 

5.103 

4.907 

4.519 

4.2 12 

Yearly 

0.104 

0.5763 

0.9952 

1.365 

1.637 

1.776 

1.926 

2.088 

2.323 

2.599 

2.889 

3.098 

3.257 

3.435 

3.854 

4.159 

4.38 

4.712 

4.994 

5.173 

5.542 

5.81 1 

5.989 

6.355 

6.765 

7.073 

7.343 

7.595 

7.876 

8.177 

Yearly 

8.325 

7.988 

7.754 

7.466 

7.206 

6.926 

6.587 

6.082 

5.88 1 

5.756 

5.237 

5.099 

4.896 

4.513 

4.208 

Year 

1961 

1962 

1963 

1964 

1965 

1966 

1967 

1968 

1969 

1970 

1971 

1972 

1973 

1974 

1975 

1976 

1977 

1978 

1979 

1980 

1981 

1982 

1983 

1984 

1985 

1986 

1987 

1988 

1989 

1990 

Peak 

0.1828 

0.4642 

0.7163 

0.865 

1.108 

1.263 

1.455 

1.795 

2.305 

2.5 12 

2.808 

2.994 

3.177 

3.46 

3.658 

3.771 

3.963 

4.202 

4.63 

4.773 

5.155 

5.294 

5.521 

5.755 

5.945 

6.09 

6.364 

6.53 1 

6.794 

7.02 

Sorted results 

Prob. Peak 96 hr 

0.0322580645 16129 

0.0645 16129032258 1 

0.0967741 93548387 1 

0.1290322580645 16 

0.16 1290322580645 

0.193548387096774 

0.22580645 1612903 

0.25806451 6129032 

0.290322580645 16 1 

0.322580645 161 29 5.155 

0.35483870967741 9 

0.387096774 193548 

0.419354838709677 

0.45 1612903225806 

0.483870967741 936 

0.5 16 129032258065 

0.548387096774194 

0.580645 161290323 

0.61 2903225806452 

0.6451 61 29032258 1 

0.67741 935483871 2.5 12 

0.7096774 19354839 

0.74 1935483870968 

0.774 193548387097 

0.80645 161 2903226 

0.8387096774 19355 

0.87096774 1935484 

21 Day 

0.1818 

0.4589 

0.7141 

0.8637 

1.105 

1.261 

1.452 

1.791 

2.299 

2.5 1 

2.804 

2.991 

3.176 

3.456 

3.656 

3.769 

3.961 

4.201 

4.624 

4.77 1 

5.152 

5.293 

5.518 

5.753 

5.943 

6.089 

6.361 

6.529 

6.79 

7.0 17 

21 Day 

7.02 

6.794 

6.53 1 

6.364 

6.09 

5.945 

5.755 

5.521 

5.294 

5.154 

4.773 

4.63 

4.202 

3.963 

3.771 

3.658 

3.46 

3.177 

2.994 

2.808 

2.5 12 

2.305 

1.795 

1.455 

1.263 

1.108 

0.865 

60 Day 

0.1763 

0.456 

0.7097 

0.8574 

1.093 

1.252 

1.45 

1.784 

2.294 

2.507 

2.801 

2.989 

3.172 

3.437 

3.652 

3.767 

3.957 

4.175 

4.616 

4.755 

5.148 

5.289 

5.512 

5.749 

5.937 

6.087 

6.295 

6.52 1 

6.775 

7.013 

60 Day 

7.019 

6.793 

6.53 

6.363 

6.09 

5.944 

5.755 

5.52 

5.293 

5.152 

4.773 

4.629 

4.202 

3.962 

3.77 

3.657 

3.46 

3.177 

2.993 

2.807 

2.5 1 

2.304 

1.795 

1.454 

1.262 

1.107 

0.8647 

90 Day 

0.1664 

0.449 

0.6821 

0.84 17 

1.063 

1.238 

1.435 

90 Day 

7.017 

6.79 

6.529 

6.36 1 

6.089 

5.943 

5.753 

5.518 

5.293 

5.148 

4.771 

4.624 

4.201 

3.961 

3.769 

3.656 

3.456 

3.176 

2.991 

2.804 

2.507 

2.299 

1.791 

1.452 

1.261 

1.105 

0.8637 

Yearly 

0.04935 

0.2507 

0.5094 

0.7396 

0.9148 

1.133 

1.305 

1.535 

1.917 

2.338 

2.582 

2.843 

3.04 

3.228 

3.491 

3.68 

3.818 

4.013 

4.29 

4.634 

4.868 

5.179 

5.341 

5.565 

5.789 

5.975 

6.134 

6.389 

6.582 

6.836 

Yearly 

7.013 

6.775 

6.521 

6.295 

6.087 

5.937 

5.749 

5.512 

5.289 

5.144 

4.755 

4.616 

4.175 

3.957 

3.767 

3.652 

3.437 

3.172 

2.989 

2.801 

2.498 

2.294 

1.784 

1.45 

1.252 

1.093 

0.8574 
0. I 6.5 143 6.5 133 6.5 122 6.4984 6.4762 6.3635 

Average of yearly averages: 3.498961 66666667 

Inputs generated by pe4.pl- 8-August-2003 

Data used for this run: 

Output File: OR wheat 

Mettile: w24232.dvf 

PRZM scenario: 0RwheatOP.txt 

EXAMS environment file: pond298.e~~ 

Chemical Name: pyrasulfotole 

Description Variable Name Value Units Comments 

Molecular weight mwt 362.3 glmol 

Henry's Law Const. henry 3.5e- 14 atm-mA3/mol 

Vapor Pressure vapr 5. l e-9 torr 

Solubilitysol 6.9e4 mglL 

Kd Kd mg/L 

Koc Koc 122 mg/L 

Photolysis half-life kdp 0 days Half-life 

Aerobic Aquatic Metabolism kbacw 0 days Halfife 

Anaerobic Aquatic Metabolism kbacs 0 days Halfife 

Aerobic Soil Metabolism asm 439 days Halfife 

Hydrolysis: pH 7 0 days Half-life 

Method: CAM 2 integer See PRZM manual 

Incorporation Depth: DEPl cm 

Application Rate: TAPP 0.05 kglha 

Application Efficiency: APPEFF 0.95 fraction 

Spray Drift DRFT 0.05 fraction of application rate applied to pond 

Application Date Date 819 dd/mm or ddimmm or dd-mm or dd-mmm 

Record 17: FILTRA 

IPSCND 1 

UPTKF 

Record 18: PLVKRT 

PLDKRT 

FEXTRC 0.5 

Flag for Index Res. Run 1R Pond 

Flag for runoffcalc. RUNOFFnone none, monthly or total(average of entire run) 

TX Wheat 

stored as TX wheat.out 

Chemical: pyrasulfotole 

PRZM environment: TXwheatOP.txt modified Satday, 12 October 2002 at 16:30:22 

EXAMS environment: pond298.e~~ modified Thuday, 29 August 2002 at 15:33:30 

Metfile: w 13958.dvf modified Wedday, 3 July 2002 at 08:06:24 

Water segment concentrations (ppb) 

Year 

1961 

1962 

1963 

1 964 

1965 

1966 

1967 

1968 

1969 

1970 

Peak 

0.3997 

0.5369 

0.6539 

2.123 

2.519 

2.595 

3.07 

3.279 

3.466 

3.807 

21 Day 

0.3913 

0.5326 

0.65 1 1 

2.093 

2.51 1 

2.592 

3.06 

3.274 

3.463 

3.8 

60 Day 

0.335 

0.5 138 

0.648 

2.053 

2.501 

2.588 

3.019 

3.2 13 

3.414 

3.79 

90 Day 

0.245 1 

0.4821 

0.628 1 

1.7 

2.398 

2.569 

2.9 

3.167 

3.38 1 

3.723 

Yearly 

0.06045 

0.385 

0.5507 

0.901 1 

2.061 

2.499 

2.665 

3.052 

3.284 

3.5 16 
Sorted results 

Prob. Peak 96 hr 

0.0322580645 161 29 

0.0645 161290322581 

0.096774 1935483871 

0.1290322580645 16 

0.16 1290322580645 

0.193548387096774 

0.22580645 16 12903 

0.2580645 16 129032 

0.290322580645 161 

0.322580645 161 29 7.5 1 

0.35483870967741 9 

0.3870967741 93548 

0.4 19354838709677 

0.45 161 2903225806 

0.483870967741 936 

0.5 161 29032258065 

0.548387096774 194 

0.580645 161 290323 

0.61 2903225806452 

0.645 161 29032258 1 

0.67741935483871 3.807 

0.70967741 9354839 

0.74 1935483870968 

0.774193548387097 

0.80645 161 2903226 

0.83870967741 9355 

0.870967741 935484 

0.90322580645 16 13 

0.935483870967742 

0.967741 93548387 1 

2 1 Day 60 Day 

10.73 10.72 

10.3 10.3 

9.978 9.977 

9.88 9.879 

9.628 9.626 

9.321 9.316 

8.575 8.571 

7.873 7.873 

7.742 7.741 

7.509 7.508 

7.429 7.427 

6.876 6.876 

6.785 6.783 

6.179 6.179 

6.014 6.012 

5.738 5.735 

5.113 5.112 

4.853 4.852 

4.687 4.684 

4.059 4.058 

3.805 3.8 

3.466 3.465 

3.279 3.278 

3.07 3.068 

2.595 2.594 

2.519 2.518 

2.123 2.117 

0.6539 0.6533 

0.5369 0.5365 

0.3997 0.398 

90 Day 

10.72 

10.29 

9.976 

9.875 

9.61 8 

9.301 

8.561 

7.87 

7.738 

7.505 

7.42 1 

6.859 

6.774 

6.176 

6.006 

5.723 

5.1 1 

4.847 

4.674 

4.055 

3.79 

3.463 

3.274 

3.06 

2.592 

2.51 1 

2.093 

0.65 1 1 

0.5326 

0.39 13 

9.9359 

Average 

Yearly 

10.68 10.58 

10.28 10.21 

9.971 9.953 

9.855 9.782 

9.608 9.526 

9.278 9.132 

8.54 8.407 

7.868 7.841 

7.719 7.666 

7.482 7.402 

7.355 7.244 

6.833 6.812 

6.737 6.569 

6.171 6.134 

5.997 5.928 

5.703 5.563 

5.106 5.043 

4.84 4.789 

4.66 4.531 

4.038 3.985 

3.723 3.516 

3.414 3.381 

3.213 3.167 

3.019 2.9 

2.588 2.569 

2.501 2.398 

2.053 1.7 

0.648 0.6281 

0.5 138 0.482 1 

0.335 0.2451 

9.8538 

: of yearly averages: 

Inputs generated by pd.pl - 

Data used for this run: 

Output File: TX wheat 

Metfile: w13958.dvf 
PRZM scenario: TXwheatOP.txt 

EXAMS environment file: pond298.e~~ 

Chemical Name: pyrasulfotole 

Description Variable Name Value Units Comments 

Molecular weight mwt 362.3 glmol 

Henry's Law Const.henry 3.5e-14 atm-mA3/mol 

Vapor Pressure vapr 5. l e-9 torr 

Solubilitysol 6.9e4 mg1L 

Kd Kd mg/L 

Koc Koc 122 mg/L 

Photolysis half-life kdp 0 days Half-life 

Aerobic Aquatic Metabolism kbacw 0 days Halfife 

Anaerobic Aquatic Metabolism kbacs 0 days Halfife 

Aerobic Soil Metabolism asm 439 days Halfife 

Hydrolysis: pH 7 0 days Half-life 

Method: CAM 2 integer See PRZM manual 

Incorporation Depth: DEPl cm 

Application Rate: TAPP 0.05 kgha 

Application Efficiency: APPEFF 0.95 fraction 

Spray Drift DRFT 0.05 fraction of application rate applied to pond 

Application Date Date 17/10 ddlmm or ddlmmm or dd-mm or dd-mmm 

Record 17: FILTRA 

IPSCND I 

UPTKF 

Record 18: PLVKRT 

PLDKRT 

FEXTRC 0.5 

Flag for Index Res. Run IR Pond 

Flag for runoff calc. RUNOFFnone none, monthly or total(average of entire run) 
APPENDIX D: Input Parameters and Results from T-REX 

BIRDS: 

Table D.a. Input Parameters for T-REX 

Table D.b. Upper 90th Percentile Kenaga, Chronic Avian Dietary 

Based Risk Ouotients 

Table D.c. Mean Kenaga, Chronic Avian Dietary Based Risk Quotients I 

EECs and RQs 

Short Grass 

NOAEC 

(PP~) 

167 

Tall Grass 

EEC 

3.83 

Broadleaf 

Plants/ 

RQ 

0.023 

Fruits/Pods/ 

Seeds/ 

Large 

EEC 

1.62 

RQ 

0.010 

Insects 

EEC 

2.03 

Insects 

RQ 

0.012 

EEC 

0.32 

RQ 

0.002 
MAMMALS: 

Table D.d. Upper 90th Percentile Kenaga, Chronic Mammalian Dietary Based Risk 

Quotients 

Table D. e. Upper 90th Percentile Kenaga, Chronic Mammalian Dose-Based Risk Quotients 

(PP~) 

50 

Size class not used for dietary risk quotients 

EECs and RQs 

I EECs and RQs I I I I 

Size 

Class 

(grams) 

Table D. f Mean Kenaga, Chronic Mammalian Dietary Based Risk Quotients I 

15 

3 5 

1000 

Size class not used for dietary risk quotients 

Short Grass 

Fruits/Pods/ 

Seeds/ 

Large Insects 

Adjusted 

NOAEL 

Table D.g. Mean Kenaga, Chronic Mammalian Dose-Based Risk Quotients 

EEC 

10.80 

EEC 

0.68 

5.49 

4.45 

1.92 

RQ 

0.22 

Tall Grass 

RQ 

0.01 

Short Grass 

Broadleaf 

Plants/ 

Small Insects 

EEC 

4.95 

1 

EEC 

6.08 

RQ 

0.10 

Tall Grass 

EEC 

10.30 

7.12 

1.65 

EECs and RQs 

I I I I 

Size Class 

(grams) 

RQ 

0.12 

RQ 

1.87 

1.60 

0.86 

Broadleaf Plants/ 

Small Insects 

EEC 

4.72 

3.26 

0.76 

Adjusted 

NOAEL 

RQ 

0.86 

0.73 

0.39 

Fruitsffodsl 

Seeds/ 

Large Insects 

EEC 

5.79 

4.00 

0.93 

Short Grass 

Granivore 

RQ 

1.05 

0.90 

0.48 

EEC 

0.64 

0.44 

0.10 

Tall Grass 

RQ 

0.12 

0.10 

0.05 

EEC 

0.14 

0.10 

0.02 

RQ 

0.03 

0.02 

0.01 

Broadleaf Plants1 

Insects 

Fruits/Pods/ 

Seeds/ 

Large Insects 

Granivore 
Table D.h. Input Parameters for T-REX 

Table D.i. Upper 90th Percentile Kenaga, Chronic Mammalian Dietary Based Risk 

Quotients 

NOAEC 

(PP~) 

0 

Table D.j. Upper 90th Percentile Kenaga, Chronic Mammalian Dose-Based Risk Quotients 

Size 

'lass 

(grams) 

15 

3 5 

1000 

Size class not used for dietary risk quotients 

EECs and RQs 

Adjusted 

NOAEL 

23.06 

152.78 

3.18 

Short Grass 

EEC 

5.52 

EECs and RQs 

RQ 

0.44 

Tall Grass 

Short Grass 

EEC 

2.53 

RQ 

0.54 

Broadleaf Plants1 

Small Insects 

Tall Grass 

EEC 

3.11 

FruitsIPodsl 

Seedsl 

Large Insects 

RQ 

0.06 

EEC 

0.35 

Broadleaf Plants1 

Small Insects 

EEC 

insectivores 

1000.00 

1538.32 

RQ 

0.01 

Fruits/Pods/ 

Seeds1 

Large Insects 

RQ 

0.96 

0.82 

EEC 

Grainvores 

35.00 

3556.56 

Granivore 

RQ 

0.54 

0.46 

0.25 

EEC 

0.00 

15.00 

EEC 

0.00 

1000.00 

1538.32 

RQ 

0.44 

0.37 

RQ 

0.06 

0.05 

0.03 

EEC 

0.07 

0.05 

0.20 0.01 

RQ 

0.01 

0.01 

0.01 

I 4395. 

0.44 66 
APPENDIX E: TerrPlant Model 

Exposure to Terrestrial Plants including Wetlands (August 8,2001; version 1 .O) 

Terrestrial plants inhabiting dry and semi-aquatic (wetland) areas may be exposed to 

pesticides from runoff and/or spray drift. Semi-aquatic areas are low-lying wet areas that 

may dry up at times throughout the year. 

EFED's runoff scenario is (1) based on a pesticide's water solubility and the amount ot 

pesticide present on the soil surface and its top one inch, (2) characterized as "sheet 

runoff' (one treated acre to an adjacent acre) for dry areas, (3) characterized as "channel 

runoff' (1 0 acres to a distant low-lying acre) for semi-aquatic or wetland areas, and (4) 

based on percent runoff values of 0.01,0.02, and 0.05 for water solubilities of <lo, 

10- 1 00, and > 100 ppm, respectively. 

EFED's Spray Drift scenario is assumed as (1) 1 % for ground application, and (2) 5% for 

aerial, airblast, forced air, and spray chemigation applications. The spray drift ratio used 

here is in agreement with the policy procedures at the time the worksheet was designed. 

Currently, 1) this worksheet is designed to derive the plant exposure concentrations from 

a single, maximum application rate only. 2) For pesticide applications with incorporation 

of depth of less than 1 inch, the total loading EECs derived for the incorporation method 

will be same as the unincorporated method. 

To calculate RQ values for Non-listed Terrestrial Plants: 

Terrestrial Plants Inhabiting Areas Adjacent to Treatment Site: 

Emergence RQ = Total Loading to Adjacent Area or EECISeedling Emergence 

EC25 

Drift RQ = Drift EECNegetative Vigor EC25 

Terrestrial Plants Inhabiting Semi-aquatic Areas Adjacent to Treatment Site: 

Emergence RQ = Total Loading to Semi-aquatic Area or EECISeedling 

Emergence EC25 Drift RQ = Drift EECIVegetative Vigor EC25 

To calculate RQ values for Listed Terrestrial Plants: 

Listed Terrestrial Plants Inhabiting Areas Adjacent to Treatment Site: 

Emergence RQ = Total Loading to Adjacent Area or EECISeedling Emergence 

EC05 

Drift RQ = Drift EECIVegetative Vigor EC05 or NOAEC 
Listed Terrestrial Plants Inhabiting Semiaquatic Areas Near Treatment Site: 

Emergence RQ = Total Loading to Semiaquatic Area or EECISeedling 

Emergence EC05 

Drift RQ = Drift EECNegetative Vigor EC05 or NOAEC 

Formulas used to calculate EEC values (8108101 ; version 1 .O) 

To calculate EECs for terrestrial plants inhabiting in areas adjacent to treatment sites 

Un-incorporated Ground Application (Non-granular): 

Sheet Runoff = Application Rate (lb ai/A) x Runoff Value 

Drift = Application Rate (lb ai/A) x 0.01 

Total Loading = EEC = Sheet Runoff + Drift 

Incorporated Ground Application with Drift (Non-granular): 

Sheet Runoff = [Application Rate (lb ai/A)/Incorporation Depth (inch)] x Runoff 

Value 

Drift = Application Rate (lb ai1A) x 0.01 

Total Loading = EEC = Sheet Runoff + Drift 

Un-incorporated Ground Application (Granular): 

Sheet Runoff = EEC = Application Rate (lb ai1A) x Runoff Value 

Incorporated Ground Application without Drift (Granular): 

Sheet Runoff = EEC = [Application Rate (lb ai/A)/Incorportion Depth (inch)] 

x Runoff Value 

AerialIAirblastlSpray Chemigation Applications: 

Sheet Runoff = Application Rate (lb ai/A) x Runoff Value x Application 

Efficiency of 0.6 

Drift = Application Rate (lb ai1A) x 0.05 

Total Loading = EEC = Sheet Runoff + Drift 

Runoff Value = 0.01,0.02, or 0.05 when the solubility of the chemical is <lo ppm, 

1 0- 100 ppm, or> 100 ppm, respectively 

Incorporation Depth: Use the minimum incorporation depth reported on the label. 
APPENDIX F: Results from Submitted Eco Toxicity Studies for Pyrasulfotole 

ANIMALS 

SPECIES I ENDPOINT I DURATION I MRID I CLASSIFICATION ( COMMENTS 

ACUTE 

TERRESTRUL 

Colinus 

virginiunus 

Northern 

bobwhite quail 

Colinus 

virginianus 

Northern 

bobwhite quail 

Anas 

platyrhynchos 

Mallard duck 

Wistar rat 

Apis mellifera 

Honey bee 

Apis mellifera 

Honey Bee 

Eisenia foetida 

Earthworm 

AQUATIC 

LDso = 

>2000 mg 

a.i./kg-bw 

= 

>49 1 1 mg 

a.i./kg diet 

LCSo = 

>5089 mg 

a.i./kg diet 

LD50 = 

>2,000 mg 

a.i.lkg-bw 

LD50 = >I20 

pg a.l./bee 

LDso = >75 

pg a.i./bee 

LCs0/ECs0 = 

>I000 mg 

a.i./kg 

NO AEC = 

>lo00 mg 

a.i./kg 

14-day 

8-day 

8-day 

14-day 

Terrestrial 

72-hr 

72-hr 

14-day 

Fish 

Birds 

Oncorhychus 

mykiss 

Rainbow trout 

Lepm is 

macrochirus 

Bluegill 

sunfish 

Cyprinodon 

variegates 

4680 17-29 

46801 7-30 

46017-3 1 

LCso = >96 

mg a.i./L 

= 

~96.5 mg 

a.i.iL 

= >I00 

mg a.i./L 

Acceptable 

Acceptable 

Acceptable 

Acute oral test; 

NOAEL = >2000 

mg a.i./kg-bw 

Acute dietary test; 

NOAEC = >49 1 1 

mg a.i.lkg diet 

Acute dietary; 

NOAEC = 5089 

mg a.i./kg diet 

Mammals 

46801 836 

Invertebrates 

46801 7-34 

46801 7-35 

4680 17-4 1 

96-hr 

96-hr 

96-hr 

Acceptable 

4680 17-24 

46801 7-25 

46801 7-26 

Acute oral; 

LOAEL = 500 

mglkg-bw 

(increased 

incidents of 

corneal opacity, 

corneal 

neovascularization 

and retinal 

degeneration) 

Acceptable 

Acceptable 

Acceptable 

Supplemental 

Supplemental 

Supplemental 

Limit test; static 

conditions 

Limit test; static 

conditions 

Limit test; static 

conditions 

Oral toxicity 

Contact toxicity; 

only a solvent 

control and no 

negative control 

was tested 

Non-guideline 

(EPA requires 28- 

day test) 
SPECIES 

Sheepshead 

minnow 

ENDPOINT DURATION 

Daphnia 

magna 

Crassostrea 

virginica 

Eastern oyster 

Americamysis 

bahia 

Mysid 

Aquatic 

48-hr 

96-hr 

96-hr 

ECso = 

>95.8 mg 

a.i.1L 

ECso = >I04 

mg a.i..lL 

LCSO = 1.1 

mg a.i./L 

MRID 

CHRONIC 

TERRESTRIAL 

Invertebrates 

468017-2 1 

4680 17-22 

468017-23 

CLASSIFICATION 

Slight reduction in 

hatchling weight 

Male body-weight 

gain 

Delays of balanopreputial and 

increased corneal 

opacity (LOAEL 

= 26.3 mgikg 

bwlday in males 

and 32.6 mglkgbwlday in 

females) 

Colinus 

virginianus 

Northern 

bobwhite quail 

Anas 

platyrhynchos 

Mallard duck 

Wistar rat 

AQUATIC 

COMMENTS 

Acceptable 

Acceptable 

Acceptable 

Limit test; static 

conditions 

Limit test; flowthrough 

conditions 

Static conditions 

NOAEC = 

205 mg 

a.i./kg diet 

LOAEC = 

594 mg 

ai.i.ikg diet 

NOAEC = 

167 mg 

a.i./kg diet 

LOAEC = 

557 mg 

a.i./kg diet 

NOAEL - 

2.5 mglkgbwiday 

Fish 

Pimephales 

promelas 

Fathead 

minnow 

Daphnia 

magna 

22-week 

20-week 

2-generation 

NOAEC = 

0.58 mg 

a.i.1L 

(reduction in 

total length) 

NOAEC = 

12.8 mg 

a.i.1L 

Birds 

468017-32 

468017-33 

Mammals 

46801907 

Acceptable 

Acceptable 

Acceptable 

35-day 

Aquatic 

2 1 -day 

468017-28 Acceptable Flow-through 

conditions 

Static renewal 

conditions; ECso = 

>52.9 mg a.i./L 

(highest conc. 

tested) 

Invertebrates 

468017-27 Acceptable 
PLANTS r 

SPECIES I ENDPOINT 1 DURATION 1 MRID 1 CLASSIFICATION 1 COMMENTS 

ACUTE 

AQUA TIC 

Lemna gibba G3 

Duckweed 

Pseudokirchneriella 

subcapitata 

Algae 

Navicula 

pelliculosa 

Algae 

Anabaenaflosaquae 

Algae 

Skeletonema 

co~tatum 

Algae 

TERRESTRLAL 

Various species; 

seedling emergence 

(AE 03 17309 02 

SE06) 

Various species; 

seedling emergence 

(AE 03 17309 + 

Bromo) 

Various species; 

vegetative vigor 

(AE 03 17309 02 

SE06) 

Various species; 

vegetative vigor 

(AE 03 17309 + 

Bromo) 

EC50/IC50 = 

28 pg a.i.1L 

EC5011C50 = 

1 1 mg a.i.1L 

EC5011C50 = 

53 mg a.i./L 

EC5dICSo = 

45.71 mg 

a.i./L 

ECSo/ICSo = 

8.3 mg a.i.1L 

Monocot: 

NIA 

Dicot: EC25 

= 0.001 1 Ib 

a.i.1acre 

NOAEC = 

0.000399 lb 

a.i./acre 

Monocot: 

NIA 

Dicot: EC25 

= 0.00025 Ib 

a.i.1acre 

NOAEC = 

0.00022 lb 

a.i.1acre 

Monocot: 

EC25 = 0.017 

lb a.i./acre 

NOAEC = 

0.0125 lb 

a.i.1acre 

m: 

EC25 = 

0.0008 1 lb 

a.i.lacre 

NOAEC = 

0.000797 lb 

a. i.lacre 

Monocot: 

NIA 

Dlco_t: 

7-day 

96-hr 

96-hr 

96-hr 

96-hr 

21 days 

21 day 

2 1 days 

2 l days 

4680 17- 

3 6 

46801 7- 

3 7 

468017- 

38 

46801 7- 

3 9 

468017- 

40 

46801 9- 

2 6 

468019- 

3 6 

4680 19- 

27 

468019- 

37 

Acceptable 

Acceptable 

Acceptable 

Supplemental 

Acceptable 

Acceptable 

Acceptable 

Supplemental 

Supplemental 

Based on 

frond dry 

weight 

Based on cell 

density and 

biomass 

Based on 

biomass 

Based on 

growth rate 

Based on 

biomass 

Based on 

tomato dry 

weight 

Based on 

tomato dry 

weight 

Based on: 

Monocots - 

Onion dry 

weight 

Dicots - 

Tomato dry 

weight 

Based on 

cucumber dry 

weight 
ENDPOINT 

a.i./acre 

NOAEC = 

<0.00012 lb 

a.i./acre 

ECos = 

0.000016 lb 

a.i./acre 

CLASSIFICATION COMMENTS '7 
APPENDIX G: Input Parameters from AgDRIFT 

AgDRIFTE Input Data Summary 

Tier: I11 Aerial Application 

Title: Pyrasulfotole 

Notes: Fine to Medium Droplet Size Distribution 

Default values appear when they differ from the Current values. 

--Aircraft-- ----------Current----------- ---------- 

Default----------- 

Name Air Tractor AT-401 

Type Basic 

Boom Height ( f t) 10 

Flight Lines 2 0 

Wing Type Fixed-Wing 

Semispan ( f t ) 24.5 

Typical Speed (mph) 119.99 

Biplane Separation (ft) 0 

Weight (lbs) 6000 

Planform Area (ft2) 294 

Propeller RPM 2000 

Propeller Radius ( f t ) 4.5 

Engine Vert Distance (ft) -1.2 

Engine Fwd Distance (ft) 11.9 

-Drop Size Distribution 1- ----------Current----------- ---------- 

Default----------- 

Name ASAE Fine to Medium 

TYP e Basic 

Drop Categories # Diam (um) Frac Diam (urn) 

Frac 

1 10.77 0.0010 

2 16.73 0.0003 

3 19.39 0.0007 

4 22.49 0.0003 

5 26.05 0.0007 

6 30.21 0.0010 

7 35.01 0.0010 

8 40.57 0.0020 

9 47.03 0.0033 

10 54.50 0.0053 

11 63.16 0.0067 

12 73.23 0.0090 

13 84.85 0.0133 

14 98.12 0.0223 

15 113.71 0.0330 

16 131.73 0.0393 

17 152.79 0.0480 

18 177.84 0.0647 

19 205.84 0.0830 

2 0 238.45 0.1147 

2 1 276.48 0.1283 

2 2 320.60 0.1380 

2 3 372.18 0.1127 

2 4 430.74 0.0640 
--Nozzle Distribution-- ----------Current----------- ---------- 

Default----------- 

Name Nozzles for Air Tractor A... 

TYP e Basic 

Horiz Distance Limit (%) 0 

Boom Length (%) 76.3 

Nozzle DSD & Locations # DSD H(ft) V(ft) F(ft) DSD H(ft) 

V(ft) F(ft) 

1 1 -18.7 0 0 

2 1 -17.79 0 0 

3 1 -16.87 0 0 

4 1 -15.96 0 0 

5 1 -15.05 0 0 

6 1 -14.14 0 0 

7 1 -13.22 0 0 

8 1 -12.31 0 0 

9 1 -11.4 0 0 

10 1 -10.49 0 0 

11 1 -9.58 0 0 

12 1 -8.66 0 0 

13 1 -7.75 0 0 

14 1 -6.84 0 0 

15 1 -5.93 0 0 

16 1 -5.02 0 0 

17 1 -4.1 0 0 

18 1 -3.19 0 0 

19 1 -2.28 0 0 

2 0 1 -1.37 0 0 

2 1 1 -0.456 0 0 

2 2 1 0.456 0 0 

2 3 1 1.37 0 0 

2 4 1 2.28 0 0 

2 5 1 3.19 0 0 

2 6 1 4.1 0 0 

2 7 1 5.02 0 0 

2 8 1 5.93 0 0 

2 9 1 6.84 0 0 

3 0 1 7.75 0 0 

3 1 1 8.66 0 0 

3 2 1 9.58 0 0 

3 3 1 10.49 0 0 

3 4 1 11.4 0 0 

3 5 1 12.31 0 0 

3 6 1 13.22 0 0 

3 7 1 14.14 0 0 

3 8 1 15.05 0 0 

3 9 1 15.96 0 0 

4 0 1 16.87 0 0 

4 1 1 17.79 0 0 
--Swath-- ----------Current----------- ---------- Default----------- 

Swath Width 60 ft 

Swath Displacement 0.3702 x Swath Width 

Half Boom No 

--Spray Material-- ---------- CurrentDefault----------- 

Name 

TYP e 

Nonvolatile Rate (lb/ac) 

Active Rate (lb/ac) 

Spray Volume 

Rate (gal/ac) 

Specific Gravity 

Evaporation 

Rate (vm2/deg C/sec) 

Water 

Basic 

0.501 

0.2505 

--Meteorology-- ----------Current----------- ---------- 

Default----------- 

Wind Speed (mph) 10 

Wind Direction (deg) -90 

Temperature (deg F) 8 6 

Relative Humidity (%) 5 0 

--Transport-- ----------current----------- ---------- Default----------- 

Flux Plane ( f t) 0 

--Terrain-- ----------current----------- ---------- Default----------- 

Surface Roughness (ft) 0.0246 

--Advanced-- ----------Current----------- ---------- Default----------- 

Wind Speed Height ( f t ) 6.56 

6.56 

Max Compute Time (sec) 6 0 0 

Max Downwind Dist (ft) 5280 

2608.24 

Vortex Decay Rate (mph) 1.25 

1.25 

Aircraft Drag Coeff 0.1 

Propeller Efficiency 0.8 

Ambient Pressure (in hg) 29.91 

29.91 

AgDRIFTB Input Data Summary 

--General-- 

Tier: I11 Aerial Application 

Title: Pyrasulfotole 

Notes: ~edium to Coarse Droplet Size ~istribution 

Default values appear when they differ from the Current values. 
--Aircraft-- ----------Current----------- ---------- 

Default-..--------- 

Name Air Tractor AT-401 

Type Basic 

Boom Height ( f t ) 10 

Flight Lines 2 0 

Wing Type Fixed-Wing 

Semispan (ft) 24.5 

Typical Speed (mph) 119.99 

Biplane Separation ( f t ) 0 

Weight (lbs) 6 0 0 0 

Planform Area (ft2) 294 

Propeller RPM 2000 

Propeller Radius (ft) 4.5 

Engine Vert Distance (ft) -1.2 

Engine Fwd Distance (ft) 11.9 

-Drop Size Distribution 1- ----------Current----------- ---------- 

Default----------- 

Name ASAE Medium to Coarse ASAE 

Fine to Medium 

Type Basic 

Drop Categories 

Frac 

Diam (um) Frac Diam (um) 
--Nozzle Distribution-- ----------Current----------- ---------- 

Default----------- 

Name Nozzles for Air Tractor A... 

Type Basic 

Horiz Distance Limit (8) 0 

Boom Length (%) 76.3 

Nozzle DSD & Locations # DSD H(ft) V(ft) F(ft) DSD H(ft) 

V(ft) F(ft) 

1 1 -18.7 0 0 

2 1 -17.79 0 0 

3 1 -16.87 0 0 

4 1 -15.96 0 0 

5 1 -15.05 0 0 

6 1 -14.14 0 0 

7 1 -13.22 0 0 

8 1 -12.31 0 0 

9 1 -11.4 0 0 

10 1 -10.49 0 0 

11 1 -9.58 0 0 

12 1 -8.66 0 0 

13 1 -7.75 0 0 

14 1 -6.84 0 0 

15 1 -5.93 0 0 

16 1 -5.02 0 0 

17 1 -4.1 0 0 

18 1 -3.19 0 0 

19 1 -2.28 0 0 

2 0 1 -1.37 0 0 

2 1 1 -0.456 0 0 

2 2 1 0.456 0 0 

2 3 1 1.37 0 0 

2 4 1 2.28 0 0 

2 5 1 3.19 0 0 

2 6 1 4.1 0 0 

2 7 1 5.02 0 0 

2 8 1 5.93 0 0 
--Swath- - ----------Current----------- ---------- 

Default----------- 

Swath Width 60 ft 

Swath Displacement 0.2781 x Swath Width 0.3702 

x Swath Width 

Half Boom No 

--Spray Material-- - - 

Default-------..--- 

Name 

Type 

Nonvolatile Rate (lb/ac) 

Active Rate (lb/ac) 

Spray Volume 

Rate (gal/ac) 

Specific Gravity 

Evaporation 

Rate (pm2/deg C/sec) 

Water 

Basic 

0.501 

0.2505 

--Meteorology-- ----------Current----------- ---------- 

Default----------- 

Wind Speed (mph) 10 

Wind Direction (deg) - 9 0 

Temperature (deg F) 8 6 

Relative Humidity (%) 5 0 

--Transport-- ----------current----------- ---------- 

Default----------- 

Flux Plane (ft) 0 

--Terrain-- ----------Current----------- ---------- 

Default----------- 

Surface Roughness (ft) 0.0246 

--Advanced-- ----------Current----------- ---------- 

Default----------- 

Wind Speed Height (ft) 6.56 

6.56 

Max Compute Time (sec) 600 

Max Downwind Dist (ft) 5280 

2608.24 
Vortex Decay Rate (mph) 

1.25 

Aircraft Drag Coeff 

Propeller Efficiency 

Ambient Pressure (in hg) 

29.91 

AgDRIFlW Input Data Summary 

--General-- 

Tier: I Ground Application 

Title: Pyrasulfotole 

Notes: Fine to Medium/Coarse Droplet Size Distribution 

----------current----------- ---------- 

Default----------- 

Application Method Ground 

Aerial 

Application Selection High Boom, ASAE Fine to M... 

ASAE Fine 
APPENDIX H: Federally Listed Species that Co-Occur with Potential Pyrasulfotol 

Use Sites at the County-Level (Based on LOCATES). 

Species that Could Be Potentiallv DIRECTLY Affected bv Pvrasulfotole Use: 

Species Common Name: 

Allocarya, Calistoga 

Ambrosia, San Diego 

Ambrosia, South Texas 

Aster, Ruth's Golden 

Avens, Spreading 

Ayenia, Texas 

Barberry, Island 

Barberry, Nevin's 

Bear-poppy, Dwarf 

Bedstraw, Island 

Bird's-beak, Palmate-bracted 

Bird's-beak, Pennell's 

Bird's-beak, salt marsh 

Bird's-beak, Soft 

Bittercress, Small-anthered 

Bladderpod, San Bernardino Mountains 

Bladderpod, Spring Creek 

Blazing Star, Scrub 

Blue-star, Kearney's 

Bluet, Roan Mountain 

Broom, San Clemente Island 

Buckwheat, Cushenbury 

Buckwheat, Ione (incl. Irish Hill) 

Buckwheat, Steamboat 

Bush-mallow, San Clemente Island 

Bush-mallow, Santa Cruz Island 

Buttercup, Autumn 

Button-celery, San Diego 

Cactus, Arizona Hedgehog 

Cactus, Bakersfield 

Cactus, Black Lace 

Cactus, Brady Pincushion 

Cactus, Knowlton 

Cactus, Kuenzler Hedgehog 

Cactus, Nichol's Turk's Head 

Cactus, Peebles Navajo 

Cactus, Pima Pineapple 

Cactus, San Rafael 

Cactus, Sneed Pincushion 

Cactus, Star 

Cactus, Tobusch Fishhook 

Cactus, Wright Fishhook 

Campion, Fringed 

Ceanothus, Coyote 

Chaffseed, American 

Checker-mallow, Keck's 

Checker-mallow, Kenwood Marsh 

Checker-mallow, Pedate 

Checker-mallow, Wenatchee Mountains 

Taxa: 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

No. of Co. Occurrences 

1 

6 

7 

2 

13 

5 

2 

6 

2 

2 

19 

3 

I1 

7 

9 

3 

2 

1 

4 

4 

2 

3 

1 

1 

2 

2 

1 

6 

9 

5 

6 

1 

4 

8 

8 

1 

4 

3 

10 

3 

10 

7 

13 

2 

48 

8 

3 

3 

1 
Clarkia, Pismo 

Clarkia, Presidio 

Clarkia, Vine Hill 

Cliffrose, Arizona 

Clover, Leafy Prairie 

Clover, Monterey 

Clover, Running Buffalo 

Clover, Showy Indian 

Coneflower, Smooth 

Coneflower, Tennessee Purple 

Coyote-thistle, Loch Lomond 

Crownscale, San Jacinto Valley 

Daisy, Willamette 

Dawn-flower, Texas Prairie (=Texas Bitterweed) 

Dogweed, Ashy 

Dropwort, Canby's 

Dudleya, Santa Clara Valley 

Evening-primrose, Antioch Dunes 

Fiddleneck, Large-flowered 

Flannelbush, Mexican 

Frankenia, Johnston's 

Fringe Tree, Pygmy 

Fringepod, Santa Cruz Island 

Gerardia, Sandplain 

Gilia, Hoffmann's Slender-flowered 

Gilia, Monterey 

Golden Sunburst, Hartweg's 

Goldenrod, Short's 

Goldfields, Burke's 

Goldfields, Contra Costa 

Grass, Hairy Orcutt 

Grass, Sacramento Orcutt 

Ground-plum, Guthrie's 

Harebells, Avon Park 

Harperella 

H ypericum, Highlands Scrub 

Ipomopsis, Holy Ghost 

Jewelflower, California 

Jewelflower, Tiburon 

Larkspur, Baker's 

Larkspur, San Clemente Island 

Larkspur, Yellow 

Layia, Beach 

Leather-flower, Alabama 

Leather-flower, Morefield's 

Lessingia, San Francisco 

Liveforever, Santa Barbara Island 

Lomatium, Bradshaw's 

Lomatium, Cook's 

Loosestrife, Rough-leaved 

Lousewort, Furbish 

Lupine, Clover 

Lupine, Nipomo Mesa 

Lupine, Scrub 

Malacothrix, Island 

Malacothrix, Santa Cruz Island 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 
Mallow, Kern 

Manioc, Walker's 

Manzanita, Del Mar 

Manzanita, Santa Rosa Island 

Meadowfoam, Butte County 

Meadowfoam, Large-flowered Woolly 

Meadowfoam, Sebastopol 

Meadowrue, Cooley's 

Milk-vetch, Applegate's 

Milk-vetch, Braunton's 

Milk-vetch, Clara Hunt's 

Milk-vetch, Coachella Valley 

Milk-vetch, Coastal Dunes 

Milk-vetch, Cushenbury 

Milk-vetch, Holmgren 

Milk-vetch, Jesup's 

Milk-vetch, Lane Mountain 

Milk-vetch, Mancos 

Milk-vetch, Sentry 

Milk-vetch, Shivwits 

Milk-vetch, Triple-ribbed 

Milk-vetch, Ventura Marsh 

Mint, Longspurred 

Mint, Otay Mesa 

Mint, San Diego Mesa 

Monardella, Willowy 

Monkey-flower, Michigan 

Mountainbalm, Indian Knob 

Mountain-mahogany, Catalina Island 

Mustard, Carter's 

Mustard, Slender-petaled 

Navarretia, Few-flowered 

Navarretia, Many-flowered 

Nitenvort, Amargosa 

Oxytheca, Cushenbury 

Paintbrush, San Clemente Island Indian 

Paintbrush, Soft-leaved 

Paintbrush, Tiburon 

Penny-cress, Kneeland Prairie 

Pennyroyal, Todsen's 

Penstemon, Blowout 

Pentachaeta, Lyon's 

Pentachaeta, White-rayed 

Phacelia, Clay 

Phacelia, Island 

Phlox, Texas Trailing 

Phlox, Yreka 

Pinkroot, Gentian 

Pitcher-plant, Alabama Canebrake 

Pitcher-plant, Green 

Pitcher-plant, Mountain Sweet 

Plum, Scrub 

Polygala, Lewton's 

Pondbeny 

Popcornflower, Rough 

Poppy, Sacramento Prickly 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 
Poppy-mallow, Texas 

Potentilla, Hickman's 

Rattleweed, Hairy 

Reed-mustard, Barneby 

Reed-mustard, Shrubby 

Rhododendron, Chapman 

Ridge-cress (=Pepper-cress), Barneby 

Rock-cress, Hoffmann's 

Rock-cress, Large (=Braunls) 

Rock-cress, McDonald's 

Rock-cress, Santa Cruz Island 

Rock-cress, Shale Barren 

Rock-cress, Small 

Rosemary, Short-leaved 

Rush-pea, Slender 

Sandlace 

Sand-verbena, Large-fruited 

Sandwort, Cumberland 

Sandwort, Marsh 

Sea-blite, California 

Snowbells, Texas 

Spineflower, Howell's 

Spineflower, Orcutt's 

Spineflower, Robust 

Spineflower, Slender-homed 

Spineflower, Sonoma 

Stickseed, Showy 

Stickyseed, Baker's 

Stonecrop, Lake County 

Sumac, Michaux's 

Sunflower, San Mateo Woolly 

Sunflower, Schweinitz's 

Taraxacum, California 

Tarplant, Gaviota 

Thistle, Chorro creek Bog 

Thistle, Fountain 

Thistle, La Graciosa 

Thistle, Suisun 

Thonunint, San Mateo 

Tuctoria, Green's 

Umbel, Huachuca Water 

Wallflower, Contra Costa 

Wallflower, Menzie's 

Warea, Wide-leaf 

Watercress, Gambel's 

Wild-buckwheat, Clay-loving 

Wire-lettuce, Malheur 

Wireweed 

Woodland-star, San Clemente Island 

Woolly-star, Santa Ana River 

Woolly-threads, San Joaquin 

Yerba Santa, Lompoc 

Ziziphus, Florida 

Adobe Sunburst, San Joaquin 

Amaranth, Seabeach 

Amphianthus, Little 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Joint-vetch, Sensitive 

Locoweed, Fassett's 

Lupine, Kincaid's 

Manzanita, Ione 

Manzanita, Morro 

Manzanita, Pallid 

Milk-vetch, Ash Meadows 

Milk-vetch, Deseret 

Milk-vetch, Fish Slough 

Milk-vetch, Heliotrope 

Milk-vetch, Pierson's 

Milkweed, Mead's 

Milkweed, Welsh's 

Monkshood, Northern Wild 

Navarretia, Spreading 

Paintbrush, Ash-grey Indian 

Paintbrush, Golden 

Potato-bean, Price's 

Primrose, Maguire 

Pussypaws, Mariposa 

Reed-mustard, Clay 

Rosemary, Cumberland 

Roseroot, Leedy's 

Rush-rose, Island 

Sandwort, Bear Valley 

Skullcap, Large-flowered 

Sneezeweed, Virginia 

Spineflower, Monterey 

Spiraea, Virginia 

Spurge, Hoover's 

Spurge, Telephus 

Sunflower, Pecos 

Sunray, Ash Meadows 

Tarplant, Otay 

Tarplant, Santa Cruz 

Thelypody, Howell's Spectacular 

Thistle, Pitcher's 

Thistle, Sacramento Mountains 

Thornmint, San Diego 

Townsendia, Last Chance 

Twinpod, Dudley Bluffs 

Whitlow-wort, Papery 

Wild-buckwheat, Gypsum 

Wings, Pigeon 

Yellowhead, Desert 

Arrowhead, Bunched 

Bluegrass, Napa 

Bulrush, Northeastern (=Barbed Bristle) 

Grass, California Orcutt 

Grass, Solano 

Lily, Pitkin Marsh 

Pondweed, Little Aguja Creek 

Sedge, White 

Wild-rice, Texas 

Grass, Colusa 

Grass, San Joaquin Valley Orcutt 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

Dicot 

~onocot] 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 
Pink, Swamp 

Water-plantain, Kral's 

Bat, Gray 

Bat, Indiana 

Bat, Lesser (=Sanbornls) Long-nosed 

Bat, Mexican Long-nosed 

Bat, Ozark Big-eared 

Bat, Virginia Big-eared 

Caribou, Woodland 

Deer, Columbian White-tailed 

Ferret, Black-footed 

Fox, San Joaquin Kit 

Fox, San Miguel Island 

Fox, Santa Catalina Island 

Fox, Santa Cruz Island 

Fox, Santa Rosa Island 

Jaguar 

Jaguarundi, Gulf Coast 

Jaguarundi, Sinaloan 

Kangaroo Rat, Fresno 

Kangaroo Rat, Giant 

Kangaroo Rat, Morro Bay 

Kangaroo Rat, San Bernardino Merriam's 

Kangaroo Rat, Stephens' 

Kangaroo Rat, Tipton 

Manatee, West Indian 

Mountain Beaver, Point Arena 

Mouse, Alabama Beach 

Mouse, Choctawhatchee Beach 

Mouse, Pacific Pocket 

Mouse, Perdido Key Beach 

Mouse, Salt Marsh Harvest 

Ocelot 

Panther, Florida 

Pronghorn, Sonoran 

Rabbit, Pygmy 

Rabbit, Riparian Brush 

Sheep, Sierra Nevada Bighorn 

Shrew, Buena Vista Lake Ornate 

Squirrel, Carolina Northern Flying 

Squirrel, Delmarva Peninsula Fox 

Squirrel, Mount Graham Red 

Squirrel, Virginia Northern Flying 

Vole, Amargosa 

Vole, Florida Salt Marsh 

Vole, Hualapai Mexican 

Whale, Finback 

Whale, Humpback 

Whale, northern right 

Whale, Sei 

Whale, Sperm 

Wolf, Gray 

Woodrat, Riparian 

Bear, Grizzly 

Bear, Louisiana Black 

Lynx, Canada 

Monocot 

Monocot 

~ammal~ 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Marine mml 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 

Marine mml 

Marine mml 

Marine mml 

Marine mml 

Marine mml 

Mammal 

Mammal 

Mammal 

Mammal 

Mammal 
Mouse, Preble's Meadow Jumping 

Otter, Northern Sea 

Otter, Southern Sea 

Prairie Dog, Utah 

Seal, Guadalupe Fur 

Squirrel, Northern Idaho Ground 

Mammal 24 

Marine mml 2 

Marine mml 7 

Mammal 15 

Marine mml 2 

Mammal 4 

' The monocots included here are associated with aquatic habitat classifications in LOCATES (i.e., 

Freshwater, TerrestrialiFreshwater, Vernal Pool, or Vernal PooliTerrestrial). 2 No attempt was made to eliminate species based on body size. 

Species that Could Be Potentiallv INDIRECTLY Affected bv Pvrasulfotole Use: 

Species Common Name: 

Abalone, White 

Ambersnail, Kanab 

Amphipod, Illinois Cave 

Amphipod, Noel's 

Amphipod, Peck's Cave 

Beetle, American Burying 

Beetle, Coffin Cave Mold 

Beetle, Comal Springs Dryopid 

Beetle, Comal Springs Riffle 

Beetle, Helotes Mold 

Beetle, Hungerford's Crawling Water 

Beetle, Kretschmarr Cave Mold 

Beetle, Salt Creek Tiger 

Beetle, Tooth Cave Ground 

Bobwhite, Masked 

Butterfly, Behren's Silverspot 

Butterfly, Callippe Silverspot 

Butterfly, El Segundo Blue 

Butterfly, Fender's Blue 

Butterfly, Karner Blue 

Butterfly, Lange's Metalmark 

Butterfly, Lotis Blue 

Butterfly, Mission Blue 

Butterfly, Mitchell's Satyr 

Butterfly, Myrtle's Silverspot 

Butterfly, Palos Verdes Blue 

Butterfly, Quino Checkerspot 

Butterfly, Saint Francis' Satyr 

Butterfly, San Bruno Elfin 

Butterfly, Smith's Blue 

Butterfly, Uncompahgre Fritillary 

Campeloma, Slender 

Cavefish, Alabama 

Cavesnail, Tumbling Creek 

Chub, Bonytail 

Chub, Borax Lake 

Chub, Gila 

Chub, Humpback 

Chub, Mohave Tui 

Chub, Oregon 

Chub, Owens Tui 

Taxa: 

Gastropod 

Gastropod 

Crustacean 

Crustacean 

Crustacean 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Bird 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Gastropod 

Fish 

Gastropod 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

No. of Co. Occurrences 

7 

1 

5 

4 

10 

109 
Chub, Pahranagat Roundtail 

Chub, Virgin River 

Chub, Yaqui 

Cladonia, Florida Perforate 

Combshell, Southern (=Penitent mussel) 

Combshell, Upland 

Condor, California 

Crane, Mississippi Sandhill 

Crane, Whooping 

Crayfish, Cave (Cambarus aculabrum) 

Crayfish, Nashville 

Crayfish, Shasta 

Cui-ui 

Curlew, Eskimo 

Cypress, Santa Cruz 

Dace, Ash Meadows Speckled 

Dace, Clover Valley Speckled 

Dace, Independence Valley Speckled 

Dace, Moapa 

Darter, Amber 

Darter, Bluemask (=jewel) 

Darter, Boulder 

Darter, Duskytail 

Darter, Etowah 

Darter, Fountain 

Darter, Maryland 

Darter, Okaloosa 

Darter, Relict 

Darter, Vermilion 

Darter, Watercress 

Dragonfly, Hine's Emerald 

Elktoe, Appalachian 

Fairy Shrimp, Conservancy Fairy 

Fairy Shrimp, Longhorn 

Fairy Shrimp, Riverside 

Fairy Shrimp, San Diego 

Falcon, Northern Aplomado 

Fanshell 

Fern, Aleutian Shield 

Fly, Delhi Sands Flower-loving 

Flycatcher, Southwestern Willow 

Frog, Dusky Gopher (Mississippi DPS) 

Frog, Mountain Yellow-legged 

Gambusia, Clear Creek 

Gambusia, Pecos 

Gambusia, San Marcos 

Goby, Tidewater 

Harvestman, Bee Creek Cave 

Harvestman, Bone Cave 

Harvestman, Robber Baron Cave 

Isopod, Lee County Cave 

Isopod, Socorro 

Kidneyshell, Triangular 

Kite, Everglade Snail 

Lichen, Rock Gnome 

Limpet, Banbury Springs 

Fish 

Fish 

Fish 

Lichen 

Bivalve 

Bivalve 

Bird 

Bird 

Bird 

Crustacean 

Crustacean 

Crustacean 

Fish 

Bird 

Conflcycds 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Insect 

Bivalve 

Crustacean 

Crustacean 

Crustacean 

Crustacean 

Bird 

Bivalve 

Ferns 

Insect 

Bird 

Amphibian 

Amphibian 

Fish 

Fish 

Fish 

Fish 

Arachnid 

Arachnid 

Arachnid 

Crustacean 

Crustacean 

Bivalve 

Bird 

Lichen 

Gastropod 
Lizard, Blunt-nosed Leopard 

Logperch, Conasauga 

Logperch, Roanoke 

Madtom, Pygmy 

Madtom, Scioto 

Madtom, Smoky 

Marstonia, Royal (=Royal Snail) 

Meshweaver, Braken Bat Cave 

Minnow, Rio Grande Silvery 

Mucket, Pink (Pearlymussel) 

Mussel, Acornshell Southern 

Mussel, Black (=Curtus' Mussel) Clubshell 

Mussel, Clubshell 

Mussel, Coosa Moccasinshell 

Mussel, Cumberland Combshell 

Mussel, Cumberland Elktoe 

Mussel, Cumberland Pigtoe 

Mussel, Dark Pigtoe 

Mussel, Dwarf Wedge 

Mussel, Fine-rayed Pigtoe 

Mussel, Flat Pigtoe (=Marshall's Mussel) 

Mussel, Gulf Moccasinshell 

Mussel, Heavy Pigtoe (=Judge Tait's Mussel) 

Mussel, Heelsplitter Carolina 

Mussel, Ochlockonee Moccasinshell 

Mussel, Oval Pigtoe 

Mussel, Ovate Clubshell 

Mussel, Oyster 

Mussel, Ring Pink (=Golf Stick Pearly) 

Mussel, Rough Pigtoe 

Mussel, Scaleshell 

Mussel, Shiny Pigtoe 

Mussel, Shiny-rayed Pocketbook 

Mussel, Southern Clubshell 

Mussel, Southern Pigtoe 

Mussel, Speckled Pocketbook 

Mussel, Winged Mapleleaf 

Pearlymussel, Alabama Lamp 

Pearlymussel, Appalachian Monkeyface 

Pearlymussel, Birdwing 

Pearlymussel, Cracking 

Pearlymussel, Cumberland Bean 

Pearlymussel, Cumberland Monkeyface 

Pearlymussel, Curtis' 

Pearlymussel, Dromedary 

Pearlymussel, Fat Pocketbook 

Pearlymussel, Green-blossom 

Pearlymussel, Higgins' Eye 

1 Pearlymussel, Little-wing 

Pearlymussel, Orange-footed 

Pearlymussel, Pale Lilliput 

Pearlymussel, Purple Cat's Paw 

Pearlymussel, Tubercled-blossom 

Pearlymussel, Turgid-blossom 

Pearlymussel, White Cat's Paw 

Pearlymussel, White Wartyback 

Reptile 

Fish 

Fish 

Fish 

Fish 

Fish 

Gastropod 

Arachnid 

Fish 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 

Bivalve 
Pearlymussel, Yellow-blossom 

Pebblesnail, Flat 

Pelican, Brown 

Plover, Piping 

Poolfish, Pahrump (= Pahrump Killifish) 

Prairie-chicken, Attwater's Greater 

Pseudoscorpion, Tooth Cave 

Pupfish, Ash Meadows Amargosa 

Pupfish, Comanche Springs 

Pupfish, Desert 

Pupfish, Devils Hole 

Pupfish, Leon Springs 

Pupfish, Owens 

Pupfish, Warm Springs 

Purple Bean 

Pygmy-owl, Cactus Fermginous 

Quillwort, Black-spored 

Quillwort, Louisiana 

Quillwort, Mat-forming 

Rabbitsfoot, Rough 

Rail, California Clapper 

Rail, Light-footed Clapper 

Rail, Yuma Clapper 

Rhadine exilis (ncn) 

Rhadine infernalis (ncn) 

Riffleshell, Northern 

Riffleshell, Tan 

Riversnail, Anthony's 

Rock-pocketbook, Ouachita (=Wheeler's pm) 

Rocksnail, Plicate 

Salamander, Barton Springs 

Salamander, California Tiger 

Salamander, Desert Slender 

Salamander, Santa Cruz Long-toed 

Salamander, Shenandoah 

Salamander, Sonora Tiger 

Salamander, Texas Blind 

Salmon, Atlantic 

Salmon, Chinook (Sacramento River Winter Run) 

Salmon, Chinook (Upper Columbia River Spring) 

Salmon, Coho (Central California Coast population) 

Salmon, Sockeye (Snake River population) 

Sea turtle, green 

Sea turtle, hawksbill 

Sea turtle, Kemp's ridley 

Sea turtle, leatherback 

Shiner, Cahaba 

Shiner, Cape Fear 

Shiner, Palezone 

Shiner, Topeka 

Shrike, San Clemente Loggerhead 

Shrimp, Alabama Cave 

Shrimp, California Freshwater 

Shrimp, Kentucky Cave 

Skipper, Carson Wandering 

Skipper, Laguna Mountain 

Bivalve 

Gastropod 

Bird 

Bird 

Fish 

Bird 

Arachnid 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Bivalve 

Bird 

Ferns 

Ferns 

Ferns 

Bivalve 

Bird 

Bird 

Bird 

Insect 

Insect 

Bivalve 

Bivalve 

Gastropod 

Bivalve 

Gastropod 

Amphibian 

Amphibian 

Amphibian 

Amphibian 

Amphibian 

Amphibian 

Amphibian 

Fish 

Fish 

Fish 

Fish 

Fish 

Reptile 

Reptile 

Reptile 

Reptile 

Fish 

Fish 

Fish 

Fish 

Bird 

Crustacean 

Crustacean 

Crustacean 

Insect 

Insect 
Snail, Armored 

Snail, Iowa Pleistocene 

Snail, Lioplax Cylindrical 

Snail, Morro Shoulderband 

Snail, Pecos Assiminea 

Snail, Snake River Physa 

Snail, Tulotoma 

Snail, Utah Valvata 

Snail, Virginia Fringed Mountain 

Snake, San Francisco Garter 

Sparrow, Florida Grasshopper 

Spider, Government Canyon Cave 

Spider, Madla's Cave 

Spider, Robber Baron Cave 

Spider, Spruce-fir Moss 

Spider, Tooth Cave 

Spider, Vesper Cave 

Spinedace, White River 

Spineflower, Howell's 

Spinymussel, James River 

Spinyrnussel, Tar River 

Springfish, Hiko White River 

Springfish, White River 

Springsnail, Alamosa 

Springsnail, Bmneau Hot 

Springsnail, Idaho 

Springsnail, Koster's 

Springsnail, Roswell 

Springsnail, Socorro 

Squawfish, Colorado 

Starling, Ponape Mountain 

Steelhead, (Southern California population) 

Stickleback, Unarmored Threespine 

Stimpshell 

Stork, Wood 

Sturgeon, Alabama 

Sturgeon, Pallid 

Sturgeon, Shortnose 

Sturgeon, White 

Sucker, June 

Sucker, Lost River 

Sucker, Modoc 

Sucker, Razorback 

Sucker, Shortnose 

Tadpole Shrimp, Vernal Pool 

Tern, California Least 

Tern, Interior (population) Least 

Tern, Roseate 

Threeridge, Fat (Mussel) 

Toad, Arroyo Southwestern 

Toad, Houston 

Toad, Wyoming 

Topminnow, Gila (Yaqui) 

Torreya, Florida 

Trout, Gila 

Turtle, Alabama Red-bellied 

Gastropod 

Gastropod 

Gastropod 

Gastropod 

Gastropod 

Gastropod 

Gastropod 

Gastropod 

Gastropod 

Reptile 

Bird 

Arachnid 

Arachnid 

Arachnid 

Arachnid 

Arachnid 

Arachnid 

Fish 

Dicot 

Bivalve 

Bivalve 

Fish 

Fish 

Gastropod 

Gastropod 

Gastropod 

Gastropod 

Gastropod 

Gastropod 

Fish 

Bird 

Fish 

Fish 

Bivalve 

Bird 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Crustacean 

Bird 

Bird 

Bird 

Bivalve 

Amphibian 

Amphibian 

Amphibian 

Fish 

Conf7cycds 

Fish 

Reptile 
Vireo, Black-capped 

Vireo, Least Bell's 

Warbler (=Wood), Golden-cheeked 

Warbler (=Wood), Kirtland's 

Warbler, Bachman's 

Woodpecker, Ivory-billed 

Woodpecker, Red-cockaded 

Bankclimber, Purple 

Beetle, Delta Green Ground 

Beetle, Northeastern Beach Tiger 

Beetle, Puritan Tiger 

Beetle, Valley Elderbeny Longhorn 

Butterfly, Bay Checkerspot 

Butterfly, Oregon Silverspot 

Caracara, Audubon's Crested 

Catfish, Yaqui 

Cavefish, Ozark 

Chub, Hutton Tui 

Chub, Slender 

Chub, Spottin 

Cypress, Gowen 

Dace, Blackside 

Dace, Desert 

Dace, Foskett Speckled 

Darter, Bayou 

Darter, Cherokee 

Darter, Goldline 

Darter, Leopard 

Darter, Niangua 

Darter, Slackwater 

Darter, Snail 

Eagle, Bald 

Elimia, Lacy 

Fairy Shrimp, Vernal Pool 

Fatmucket, Arkansas 

Fern, Alabama S treak-sorus 

Fern, American hart's-tongue 

Frog, California Red-legged 

Frog, Chiricahua Leopard 

Gnatcatcher, Coastal California 

Isopod, Madison Cave 

Lizard, Coachella Valley Fringe-toed 

Lizard, Island Night 

Madtom, Neosho 

Madtom, Yellowfin 

Minnow, Devils River 

Minnow, Loach 

Moth, Kern Primrose Sphinx 

Mucket, Orangenacre 

Murrelet, Marbled 

Mussel, Alabama Moccasinshell 

Mussel, Fine-lined Pocketbook 

Mussel, Heelsplitter Inflated 

Naucorid, Ash Meadows 

Owl, Mexican Spotted 

Owl, Northern Spotted 

Bird 

Bird 

Bird 

Bird 

Bird 

Bird 

Bird 

Bivalve 

Insect 

Insect 

Insect 

Insect 

Insect 

Insect 

Bird 

Fish 

Fish 

Fish 

Fish 

Fish 

Conflc ycds 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Bird 

Gastropod 

Crustacean 

Bivalve 

Ferns 

Ferns 

Amphibian 

Amphibian 

Bird 

Crustacean 

Reptile 

Reptile 

Fish 

Fish 

Fish 

Fish 

Insect 

Bivalve 

Bird 

Bivalve 

Bivalve 

Bivalve 

Insect 

Bird 

Bird 
Pearlshell, Louisiana 

Plover, Western Snowy 

Rattlesnake, New Mexican Ridge-nosed 

Rocksnail, Painted 

Rocksnail, Round 

Salamander, Cheat Mountain 

Salamander, Flatwoods 

Salamander, Red Hills 

Salamander, San Marcos 

Salmon, Chinook (California Coastal Run) 

Salmon, Chinook (Central Valley Fall Run) 

Salmon, Chinook (Central Valley Spring Run) 

Salmon, Chinook (Lower Columbia River) 

Salmon, Chinook (Puget Sound) 

Salmon, Chinook (Snake River Fall Run) 

Salmon, Chinook (Snake River springlsummer) 

Salmon, Chinook (Upper Willamette River) 

Salmon, Chum (Columbia River population) 

Salmon, Chum (Hood Canal Summer population) 

Salmon, Coho (Southern ORINorthern CA Coast) 

Salmon, Sockeye (Ozette Lake population) 

Scrub-Jay, Florida 

Sculpin, Pygmy 

Sea turtle, loggerhead 

Sea turtle, olive ridley 

Shagreen, Magazine Mountain 

Shiner, Arkansas River 

Shiner, Beautiful 

Shiner, Blue 

Shiner, Pecos Bluntnose 

Silverside, Waccamaw 

Skink, Blue-tailed Mole 

Skink, Sand 

Skipper, Pawnee Montane 

Slabshell, Chipola 

Smelt, Delta 

Snail, Bliss Rapids 

Snail, Chittenango Ovate Amber 

Snail, Flat-spired Three-toothed 

Snail, Painted Snake Coiled Forest 

Snake, Concho Water 

Snake, Eastern Indigo 

Snake, Giant Garter 

Snake, Lake Erie Water 

Snake, Northern Copperbelly Water 

Sparrow, San Clemente Sage 

Spikedace 

Spinedace, Big Spring 

Spinedace, Little Colorado 

Springfish, Railroad Valley 

Alopecurus, Sonoma 

Arizona Agave 

Beargrass, Britton's 

Bluegrass, San Bernardino 

Fritillary, Gentner's 

Grass, Tennessee Yellow-eyed 

Bivalve 

Bird 

Reptile 

Gastropod 

Gastropod 

Amphibian 

Amphibian 

Amphibian 

Amphibian 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Bird 

Fish 

Reptile 

Reptile 

Gastropod 

Fish 

Fish 

Fish 

Fish 

Fish 

Reptile 

Reptile 

Insect 

Bivalve 

Fish 

Gastropod 

Gastropod 

Gastropod 

Gastropod 

Reptile 

Reptile 

Reptile 

Reptile 

Reptile 

Bird 

Fish 

Fish 

Fish 

Fish 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 
Irisette, White 

Ladies1-tresses, Canelo Hills 

Ladies1-tresses, Navasota 

Lily, Minnesota Trout 

Lily, Western 

Onion, Munz's 

Sedge, Golden 

Trillium, Persistent 

Trillium, Relict 

'Amole, Cammatta Canyon 

Amole, Purple 

Beaked-rush, Knieskern's 

Brodiaea, Thread-leaved 

Iris, Dwarf Lake 

Ladiesf-tresses, Ute 

Orchid, Eastern Prairie Fringed 

Orchid, Western Prairie Fringed 

Pogonia, Small Whorled 

Sedge, Navajo 

Steelhead, (California Central Valley population) 

Steelhead, (Central California Coast population) 

Steelhead, (Lower Columbia River population) 

Steelhead, (Middle Columbia River population) 

Steelhead, (Northern California population) 

Steelhead, (Snake River Basin population) 

Steelhead, (South-Central California population) 

Steelhead, (Upper Columbia River population) 

Steelhead, (Upper Willamette River population) 

Sturgeon, Gulf 

Sucker, Santa Ana 

Sucker, Warner 

Tortoise, Desert 

Tortoise, Gopher 

Trout, Apache 

Trout, Bull 

Trout, Bull (Columbia River population) 

Trout, Bull (Klamath River population) 

Trout, Greenback Cutthroat 

Trout, Lahontan Cutthroat 

Trout, Little Kern Golden 

Trout, Paiute Cutthroat 

Turtle, Bog (Northern population) 

Turtle, Flattened Musk 

Turtle, Ringed Sawback 

Turtle, Yellow-blotched Map 

Whipsnake (=Striped Racer), Alameda 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Monocot 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Reptile 

Reptile 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Fish 

Reptile 

Reptile 

Reptile 

Reptile 

Reptile