**UNITED ST AT**  **ES ENVIRONMENT AL**  **PROTECTION A GENCY**  **WA SHINGTON, D.C. 20460** 

**OFFICE OF CHEMCICAL SAFETY AND**  **POLLUTION PREVENTION** 

### PC code: **128905**

**DP Barcode: 404124 and**  **386992**

**August 3, 2012 MEMORANDUM**  **SUBJECT:** Revised Section 3 Environmental Fate and Ecological Risk Assessment for

Tolclofos - methyl **FROM:** Keith Sappington , Senior Biologist

Mohammed Ruhman, Senior Fate Scientist Environmental Risk Branch V Environmental Fate and Effects Division (7507P) **THROUGH:** Mah T. Shamim , Ph.D. , Branch Chief

Environmental Risk Branch V Environmental Fate and Effects Division (7507P) **TO:** Lisa Jones , Risk Manager R eviewer,

Mary Woller , Risk Manager, RM - 2 1 Fungicide Branch , Registration Division (7505P ) Please find attached a revision of the new chemical environmental fate and ecological risk assessment for the proposed seed treatment uses of tolclofos methyl effects . This revision was necessary in response to new registrant submission related to the environmental chemistry methods (ECMs) and associated Independent laboratory validations (ILVs) for residues in soil and water ( DP Barcode: 404124 **)** . It is import ant to note that the attached revised chapter do es not affect contents and summary of the major conclusions and uncertainties included in the previous memo entitled **:** Section 3 Environmental Fate and Ecological Risk Assessment for Tolclofos - methyl ( May 15, 2012 ; DP Barcode: 386992 ) .**UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460**  **OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION**  

# Environmental Fate **and Ecological Risk Assessment for Tolclofos Methyl Registration** 

**O -**  **(2,6 -**  **dichloro -**  **4 -**  **methylphenyl) O,O**  **- dimethyl phosphorothioate** 

**CAS: 57018 -**  **04 -**  **9; PC code: 128905** 

**Prepared by: Mohammed A. Ruhm**  **an, Ph.D. Keith Sappington, M.S.**  **Joseph Beam an, M.S.**  **Reviewed by: Mah Sham** **im , Ph.D.**  United States Environmental Protection Agency Office of Pesticide Programs Environmental Fate and Effects Division

Environmental Risk Branch V 1200 Pennsylvania Ave. Mail Code 7507P Washington, D.C. 20460 

### H H H H H H

H H H O O P S O Cl

Clii 

## Contents **I. EXECUTIVE SUMMARY**  ................................ ................................ ................................ ................................ . 6 A. Nature of Chemical Stressor ................................ ................................ ................................ .................. 6 B. Potential Risks to Non - target Organisms ................................ ................................ ............................... 7 C. Conclusions - Exposure Characterization ................................ ................................ .............................. 9 D. Conclusions - Effects Characterization ................................ ................................ ................................ .. 9 E. Data Gaps and Uncertainties ................................ ................................ ................................ .................. 9 1. Environmental Fate ................................ ................................ ................................ ................................ ........ 9 2. Ecological Effects ................................ ................................ ................................ ................................ ........ 10 **II. PROBLEM FORMULATION**  ................................ ................................ ................................ ..................... 10 A. Stressor Source and Distribution ................................ ................................ ................................ ......... 10 1. Stressor Of concern ................................ ................................ ................................ ................................ ...... 10 2. Source and Intensity ................................ ................................ ................................ ................................ .... 11 3. Phy si cochemical, Fate, and Transport Properties ................................ ................................ ........................ 11 4. Pesticide Type, Class, and Mode of Action (MOA) ................................ ................................ .................... 12 5. Overvie w of

Pesticide Usage ................................ ................................ ................................ ....................... 13 B. Receptors ................................ ................................ ................................ ................................ ............. 13 1. Ecological Effect s ................................ ................................ ................................ ................................ ........ 13 C. Ecosystems at Risk ................................ ................................ ................................ .............................. 15 D. Assessment Endpoints ................................ ................................ ................................ ......................... 16 E. Conceptual Model ................................ ................................ ................................ ................................ 16 1. Risk Hypotheses ................................ ................................ ................................ ................................ .......... 16 2. Conceptual Diagram ................................ ................................ ................................ ................................ .... 17 F. Analysis Plan ................................ ................................ ................................ ................................ ....... 20 1. Methods for C onducting Ecological Risk Assessment and Identification of Data Gaps ............................. 20 2. Measures of Exposure ................................ ................................ ................................ ................................ .. 22 3. Measures of Effects ................................ ................................ ................................ ................................ ..... 23 4. Measures of Ecosystem and Receptor Characteristics ................................ ................................ ................. 23 **III. ANALYSIS**  ................................ ................................ ................................ ................................ ..................... 25 A. Use Characterization ................................ ................................ ................................ ............................ 25 B. Exposure Characterization ................................ ................................ ................................ ................... 29 1. Environmental Fate and Transport Characterization ................................ ................................ ................... 30 2. Aquatic Exposure Assessment ................................ ................................ ................................ ..................... 45 3. Terrestrial Exposure Assessment ................................ ................................ ................................ ................. 63 4. Non - Target Terrestrial Plant Exposure Assessment ................................ ................................ .................... 65 C. Ecological Effects Characterization ................................ ................................ ................................ ..... 66 1. Aquatic Effects ................................ ................................ ................................ ................................ ............ 66 2. Terrestrial Effects ................................ ................................ ................................ ................................ ........ 75 **IV. RISK CHARACTERIZATION**  ................................ ................................ ................................ .................... 83 A. Ris k Estimation - Integration of Exposure and Effects Data ................................ ............................... 83 1. Non - target Aquatic Animals and Plants ................................ ................................ ................................ ...... 83 2. Non - target Terrestrial Animals ................................ ................................ ................................ .................... 91 3. Piscivorous Birds and Mammals ................................ ................................ ................................ ................. 93 4. Non - target Beneficial Insects ................................ ................................ ................................ ....................... 95 5. Non - target Terrestrial Plants ................................ ................................ ................................ ........................ 95 B. Risk Description - Interpretation of Direct Effects ................................ ................................ .............. 96 1. Risks to Aquatic Animals ................................ ................................ ................................ ............................ 96 2. Risks to Terrestrial Animals ................................ ................................ ................................ ........................ 99 3. Risks to Terrestrial Plants ................................ ................................ ................................ .......................... 101 4. Revie w of

Incident Data ................................ ................................ ................................ ............................ 102 5. T hreatened and Endangered Species Concerns ................................ ................................ ......................... 102 C. Description of Assumptions, Limitations, Uncertainties, Strengths and Data Gaps .......................... 103 1. Exposure for All Taxa ................................ ................................ ................................ ................................ 103 2. Exposure for Aquatic Species ................................ ................................ ................................ .................... 104iii

3. Exposure for Terrestrial Species ................................ ................................ ................................ ................ 105 4. Effects Assessment ................................ ................................ ................................ ................................ .... 107 **V. REFERENCES TO OPEN LITERATURE AND GOVERNMENT REPORTS**  ................................ ... 110 Appendix A. Environmental Fate Study Bibliography ................................ ................................ .............................. 111 Appendix B. Ecotoxicity Study Bibliography ................................ ................................ ................................ ........... 113 Appendix C. Data Requirements and Data Gaps ................................ ................................ ................................ ....... 121 Appendix D. Ecotoxicity Study Summaries ................................ ................................ ................................ .............. 129 Appendix E. Risk Quotient Method and Levels of Concern ................................ ................................ ..................... 142 Appendix F. Output From T - REX Model (v 1.5) ................................ ................................ ................................ ...... 144 Appendix G: Summary of Submitted Environmental Fate Studies ................................ ................................ ........... 147 Appendix H. Results from STIR and SIP Screening Tools ................................ ................................ ...................... 185iv 

## Table of Figures Figure 1 Degradates of TM resulting from abiotic and biotic transformation in a erobic/ anaerobic soil and aquatic systems. ................................ ................................ ................................ ................................ ................................ ....... 12 Figure 2. The aquatic conceptual model for seed - coat application of TM to seeds of agricultural crops (dotted lines indi cate unlikely routes of chemical dissipation) ................................ ................................ ................................ ......... 18 Figure 3. The terrestrial conceptual model for seed - coat application of TM to agri cultural crops (excluding abraded seed coat drift; dotted lines indicate unlikely routes of chemical dissipation) ................................ ............................. 19 Figure 4. The terrestrial conceptual model for seed - coat application of TM to agricultural crops via abraded seed coat drift (dotted lines indicate unlikely routes of chemical dissipation) ................................ ................................ .... 20 Figure 5. Position of radiolabel for TM used in fate and transport studies ................................ ................................ . 32 Figure 6. Un - extracted bound residues following the most effective extraction procedure; extraction procedure 2 (EP 2, Table 9, above) ................................ ................................ ................................ ................................ ........................ 39 Figure 7 Expected environmental degradation pathways for TM (degradates are color coded) ................................ .. 42 Figure 8. Surface water exposure EECs ( C ase 1 , Case 2 and Ornamentals) ................................ ............................... 62 Figure 9. Acute Risk Quotients for Freshwater Fish (top panel) and Saltwater Fish (bottom panel) Relative to LOCs (0.5=listed sp.; 0.05 = non - listed sp.) Downward arrow s denote non - definitive RQs (“<” values) ............................ 85 Figure 10. Chronic Risk Quotients for Freshwater Fish Relative to LOC (1.0). Upward arrows denote non - definitive RQs (“>” values). ................................ ................................ ................................ ................................ ........................ 86 Figure 11. Acute Risk Quotients for Freshwater (top panel) and Saltwater Invertebrates (bottom panel) Relative to Ac ute Risk LOCs (0.05 and 0.5). ................................ ................................ ................................ ................................ 88 Figure 12. Chronic Risk Quotients for Freshwater (top panel) and Saltwater Invertebrates (bottom panel) Relative to the LOC (1.0). ................................ ................................ ................................ ................................ .............................. 89v 

## Table of Tables Table 1. Taxonomic groups and test species evaluated for ecological effects in this screening - level risk assessment

................................ ................................ ................................ ................................ ................................ ..................... 13 Table 2. Toxicity endp oints used in risk quotient calculations ................................ ................................ .................... 14 Table 3. Crop use patterns and application rates for the TM new chemical registration fo r seed treatment ............... 25 Table 4. Phy sical and chemical properties of TM ................................ ................................ ................................ ....... 30 Table 5. Maximum quantities of organic volatiles found in different biotic studies (ED= Experimental duration in days; ED= Experiment duration in days; T= Incubation temperature in o C; and AR= Application rate ppm) ............ 31 Table 6. F ate properties of TM in abiotic systems ................................ ................................ ................................ ....... 33 Table 7 Available data for characteristics of soil and aquatic systems used in laboratory biotic studies. ................... 34 Table 8. Fate properties of TM in biotic systems (Refer to Table 7 above for soil identification/ characteristics and to Appendix G for a details) ................................ ................................ ................................ ................................ ............ 35 Table 9. Percentages of bound residues found in different biotic studies following varied extraction procedures studies (ED= Experimental duration in days; T= Incubation temperature in o C; AR= Application rate ppm; and EP= Extraction Procedure Number “refer to Table 10 . for description of the procedures”) ................................ ............... 37 Table 10. Description of extraction procedures used in soil and sediment extraction in biotic studies (Refer to Table 8 for a list of these studies) ................................ ................................ ................................ ................................ .......... 38 Table 11. Adsorption/Desorption properties of TM ................................ ................................ ................................ .... 43 Table 12. Modeling inputs for Case 1 and ornamentals (application rate used for all run= 0.02 lbs a.i/A)* .............. 47 Table 13. Modeling inputs for Case 2 ................................ ................................ ................................ ......................... 49 Table 14. Summary of PRZM/EXAMS environmental fate and transport data used as aquatic exposure inputs (TTR=total toxic residues). ................................ ................................ ................................ ................................ .......... 54 Table 15. Surface water 1 - in - 10 Year EECs (μg/L) for TM 1 use patterns ( Case 1 ) ................................ .................... 54 Table 16. Surface water 1 - in - 10 Year EECs (μg/L) for TM 1 use patterns ( Case 2 ) ................................ .................... 56 Table 17. Pore - water 1 - in - 10 Year EECs (μg/L) for TM 1 use patterns ( Case 1 ) ................................ ......................... 63 Table 18. Estimated Exposure of TM to Birds and Mammals Based on Label Seed Application Rates ..................... 64 Table 19. Toxicity Reference Values For Aquatic Organisms Exposed To Tolclofos Methyl and Metabolite (DM TM) ................................ ................................ ................................ ................................ ................................ .............. 67 Table 20. Toxicity Reference Values For Terrestrial Organisms Exposed To Tolclofos Methyl ................................ 76 Table 21. Acute and chronic risk quotients (RQs) for evaluating toxic risk of TM exposure to freshwater and saltwater fish ................................ ................................ ................................ ................................ ................................ 84 Table 22. Maximum Acute and chronic risk quotients (RQs) for evaluating toxic risk of TM exposure to freshwater and saltwater invertebrates ................................ ................................ ................................ ................................ .......... 86 Table 23. Subchronic and Chronic Risk Quotients for evaluating toxic risk of TM exposure to freshwater and estuarine/marine benthic invertebrates. ................................ ................................ ................................ ....................... 90 Table 24. Acute RQs for non - vascular aquatic plants exposed to TM. ................................ ................................ ....... 91 Table 25. Acute Avian RQs for Proposed TM Seed Treatment Uses ................................ ................................ .......... 91 Table 26. Acute Mammalian RQs for Proposed TM Seed Treatment Uses ................................ ................................ 92 Table 27. Chronic Mammalian RQs for Proposed TM Seed Treatment Uses ................................ ............................. 93 Table 28. Predicted residues of TM in aquatic organisms using KABAM and BCF Methods. ................................ .. 94 Table 29. Calculation of RQ values for mammals and birds consuming fish contaminated by Tolclofos Methyl. ..... 95 Table 30. Aquatic Plant Toxicity Data Obtained For Other Phosphorothionate Organophosphate Pesticides ............ 99 Table 31. Terrestrial Plant Toxicity Data Obtained For Other Phosphorothionate Organophosphate Pesticides ..... 102**6**



## I. **EXECUTIVE SUMMARY A.**  **Nature of Chemical Stressor** Tolclofos - Meth yl( O - 2,6 - dichloro - p - tol yl O , O - dimethyl phosphorothioate ) also identified as Ri z olex, Grancer, Basilex, S - 3349 ; CAS 57018 - 04 - 9 , PC code128905), and hereafter referred to as “TM” in this document, belongs to the organophosphate (OP) class of pesticides which are ty picall y known for their insecticidal modes of action. Although TM exhibits acetyl cholinesterase inhibition in animal studies, the extent of inhibition is weak relative to other OP insecticides. In this action, TM is being proposed for use as a fungicide seed treatment on numerous crops. According to the Fungicide Resistance Action Committee (FRAC), 1 

### the proposed mode of action of TM is disruption of lipid sy nthesis and membrane i ntegrity via lipid peroxidation . The fungic idal activity of TM is thought to be related to its inhibition of the zoospore mobility

of ph ycomycetous fungi and disturbance of normal cytokinesis similar to the compound cy

tochalasin A 2



### . TM is active against Rhizoctonia solani, Fusarium spp ., and other Deuteromycete fungi that cause seed decay

and seedling blights. Plant studies suggest that the chemical is not sy stemic as there was minimal translocation of the parent compound or metabolites from the seed to emerged seedlings based on submitted plant metabolism studies (MRIDs 483419 - 56/57). TM is proposed for use as a flowable fungicide (42% a.i by weight) for seed treatment (true seeds only) on fifteen crop groups: Root Vegetables (Crop Group 1 A, with exceptions; 13 Crops); Bulb Vegetabl es (Crop Group 3 - 07; 12 Crops); L eafy Vegetables (except Brassica Vegetables) (Crop Group 4; 30 Crops); Brassica (Cole) Leafy Vegetables (Crop Group 5; 16 Crops); Legume Vegetables (Succulent or Dried) (Crop Group 6; 44 Crops); Fruiting Vegetables (Crop Group 8 - 10; 22 Crops); Cucurbit vegetables (Crop Group 9; 38 Crops); Cereal Grains (Crop Group 15 except rice and wild rice; 11 Crops); Grass, Forage, Fodder, and Hay (Crop Group 17); Non - Grass animal Feeds (Forage, Fodder, Straw, and Hay) (Crop Group 18; 12 Crops); Herbs and Spices (Crop Group 19; 69 Crops); Oilseeds (Crop Group 20, except cotton; 31 Crops); Conifers; Cotton; and Ornamental Flowers. According to the registrant, TM is a contact, broad - spectrum fungicide that provides protection for planted seeds and emerging seedlings from soil borne fungal pathogens. Since TM is intended as a seed treatment, the primary source of exposure will be below the soil surface since the label indicates treated seeds may not be planted by broadcast. In this case, no spray drift is expected , although drift of abraded seed coating may occur from seed planting practices. The depth of TM placement will depend on recommended seeding depth for a given crop and the depth of the moist zone where seeds are usuall y planted. Upon planting, TM is expected to be subject to degradation within the aerobic soil sy stem with limited leaching/runoff

/volatilization. Although TM is semi volatile, its placement below the soil surface 1 FRAC. 2012. FRAC Code List ©*2012: Fungicides sorted by mode of action . http://www.frac.info/frac/publication/anhang/FRAC - Code - List2011 - final.pdf 2 http://dar.efsa.europa.eu/dar - web/p rovision**7**



### is expected to limit its ability to escape into the atmosphere possibly increasing the availability of the chemical in the soil and in aquatic compartment s of the environment , including groundwater . Degradation of TM in soil/aquatic sy stems (when i t reaches the aquatic sy stems via runoff ), is expected through three major process es : mineralization to CO 2 

### , formation of bound residues ; and degradation into few major degradates and man y minor degradates (usually < 1% each). The major/minor degradates include **DM -**  **TM** (a major degradate), **ph -**  **CH 3**  

### (mostly a minor degradate), and oxons including **DM -**  **TMO** and **TMO** (minor degradates in the soil and aquatic compartments ). These degradation products show decline to low levels , in most cases reaching limits of detection , and are not considered as part of the stressor of concern. In contrast, un characterized bound residues are considered as part of the total residues of concern in addition to parent. **B. Potential Risks to Non**  **- target Or**  **ganisms** A summary

of the major conclusions and uncertainties of this assessment for aquatic and terrestrial receptors respectively is included below. **Acute Risks Concerns to Aquatic Animals**  **.** The results of this screening - level risk assessment suggest a low likelihood of acute toxicity to fish (and to aquatic - phase amphibians for which fish serve as surrogates) and aquatic invertebrates (freshwater and saltwater) as a result of runoff of TM from se eds to adjacent surface waters. Acute effects on these taxa were at or near the limits of TM solubility

(0.7 mg ai/L). This low acute toxicity combined with the low predicted aquatic EECs (maximum = 0.34 4 ug ai/L) results in risk quotients (RQ) that are approximately 2 orders of magnitude below Agency levels of concern (LOC). **Chronic Risk Concerns to Aquatic Animals**  **.** There is a low likelihood for chronic toxic effects to aquatic invertebrates (water column and benthic dwelling), with chronic RQ values 2 - 3 orders of magnitude below the Agency L OC. Chronic risks to freshwater and saltwater fish could not be determined definitively due to lack of toxicity data (saltwater fish) and a non definitive NOAEC for freshwater fish (< 12 ug ai/L). However, estimated exposure concentrations (EEC) for evaluating the likelihood of chronic effects are 100X lower than the current LOAEC for freshwater fish (12 ug ai/L). Furthermore, the similarity in acute toxicity among freshwater and saltwater fish suggest s that saltwater fish would be of similar sensitiv ity to freshwater fish on a chronic exposure basis. Based on these lines of evidence, the risk of chronic effects to freshwater and saltwater fish from the proposed uses of TM is expected to be low . **Risks to Aquati c Plants.**  Based on limited submitted data for TM, the likelihood of adverse effects to non - vascular aquatic plants is expected to be low . However, data were only submitted for one species of algae (not the usual 4 species) and were not submitted for vascu lar aquatic plants. The uncertainty

associated with lack of aquatic plant toxicity data was characterized based on data for other phosphorothionate organophosphate pesticides. These surrogate plant toxicity data suggest the predicted EECs in surface water (maximum peak EEC of 0.344 ug ai/L) have a low potential for adverse effects to aquatic vascular and non - vascular plants.**8**



### Acute Risks Concerns for Birds and Mammals. Acute risks were evaluated on the assumption that birds and mammals consume 100% of their diet as TM - treated seed. The likelihood of acute toxicity

is considered low for both birds (and terrestrial - phase amphibians and reptiles for which birds serve as surrogates) and mammals with the proposed seed treatment rate s . No acute risk concerns were identified for piscivorous birds or mammals. **Chronic Risk Concerns for Birds and Mammals.** A potential for chronic risks to birds (and terrestrial - phase amphibians and reptiles for which birds serve as surrogates) and mammals was evaluated in this assessment based on consumption of treated seeds . Specifically , the maximum chronic RQ values derived from the root vegetables and cotton crop scenarios are equivalent to the Agency chronic risk LOC for birds (RQ=1.0) and exceed the chronic risk LOC for mammals (RQ=7.9). For birds, the chronic risk finding is highl y sensitive to the assumption of 100% of the diet consisting of treated seed since soil incorporation is required for the proposed seed treatment uses of TM. The current terrestrial exposure assessment model (T - REX v. 1.5) does not take into account the effect of soil incorporation on wildlife exposure to treated seeds. In addition, the NOAEL from the chronic avian toxicity study (500 ppm diet) is somewhat uncertain due to the wide dose spacing use d in the study (LOAEL = 2500 ppm diet). No chronic risk concerns were identified for piscivorous birds. For mammals, chronic risk concerns were identified for both seed treatment rates proposed on the label ( i.e . , both the higher rate for root vegetables and cotton and the lower rate for other vegetables). Similar to the avian risk assessment, the wide dose spacing associated with the chronic NOAEL (100 ppm diet) and LOAEL (3000 ppm) introduces uncertainty in the interpret ation of exposures that exceed the NOAEL but not the LOAEL. No chronic risk concerns were identified for piscivorous mammals. **Risk Concerns for Terrestrial Plants.** No data were submitted on the toxicity of TM to terrestrial plants. However, its use as a seed treatment and non - sy stemic characteristics minimize off

- site transport to terrestrial plants. A potential for off - site transport does exist for abraded seed coatings containing TM. The maximum application rate of TM (0.02 lb ai/A) is 1 to 2 orders of magnitude below the most sensitive plant toxicity values reported for other phosphorothionate organic pesticides, suggesting that risk concerns for terrestrial plants are low. **Risk Concerns for Beneficial Insects.** Although s pray drift is not an exposure route of concern for beneficial insects (honey bee), off - site drift of abraded seed coatings during planting is a potential route of concern. Available toxicity data for TM indicate it is practicall y non - toxic to yo ung adult honey

bee s on an acute contact exposure basis. Given the low application rate proposed for TM (0.02 lb a . i/A) and its non - sy stemic characteristics in terrestrial plants, risk concerns for pollinating insects are considered low.**9**



### C. **Con clusions**  **- Exposure Characterization**  TM is semi volatile (vapor pressure = 1.38 x 10 - 5 

### torr and Henry ’s law constant= 3.68 x 10 - 6 

### atm m 3 

### mole - 1 

### ) and is characterized by low solubility in water (0.7 mg/L at 2 0 o 

### C & 1.10 mg/L at 25 o 

### C ) . Photolysis in water and on soil is not expected to be important processes in TM dissipation in the natural environment. The pesticide is applied on seeds that are placed below the soil surface limiting exposure due t o drift, volatility and runoff

. TM breaks down through hydrol ys is and biotic degradation processes into many degradation products that are expected to be non - persistent with the exception of bound residues. Metabolites of TM are not expected to be persiste nt in the environment based on their rapid decline following formation. However, bound residues formed in high quantities in aerobic soil an d aquatic environments appear to be p ersistent and are considered to be of exposure concern. Batch adsorption/desorp tion studies indicate a low potential for mobility in soil for TM thereb y limiting the possibility of leaching. Aquatic exposure s of concern for this chemical include those that may be caused by

parent compound and bound residues reaching aquatic s ystems through limited runoff . Finall y, the n octanol water partition coefficient (Kow

### ) of TM is 6,310 (log K ow

### =3.8) suggesting a potential for bioconcentration in aquatic organisms such as fish . **D. Conclusions**  **- Effects Characterization**  For aquatic animals and plants, the acute toxicity of TM approaches its solubility in water (0.7 - 1.1 mg a . i/L). TM is considerabl y more toxic on a chronic exposure basis , with NOAECs of < 0.012 mg a . i/L for rainbow trout ( Oncorhynchus mykiss ) , 0.026 mg a . i/L for Daphnia magna , and 0.0039 mg a . i/Lfor my sid shrimp. There were n o data submitted on the toxicity of TM to aquatic vascular plants or on the chronic effects of TM on saltwater fish. For terrestrial animals, TM is practicall y non - toxic to both birds and mammals on an acute exposure basis . For birds, both the LD50 and L C 50 

### values were non - definitive (“>”) values, with the lowest being > 2000 mg a . i/kg bw for zebra finch. For mammals, the most sensitive LD 50 

### value is 3,500 mg a . i/kg - bw for mouse. TM is chronically toxic to birds at exposure levels greater than 500 ppm in the diet. For mammals, TM is chronically toxic at concentrations above 100 ppm in the diet (12.2 mg a . i/kg bw). **E. Data Gaps and Uncertainties** 

**1. Environmental Fate**  Although uncertainties and data gaps were identified with the available environmental fate studies (e.g., volatilization, nature of bound residues, supple mental classification of some of the fate studies and all of the mobility studies), the limited proposed use of this chemical ( (seed treatment only), combined with the low ecological risk findings indicate that additional data on environmental fate of TM i s of low priority at this time. However, data will be needed in case of requests for new use(s). The chemical is to be used as seed treatment only with maximum one time rate of 0.02 lbs a.i/A.**10** 

### 2. **Ecological Effects** Solubility problems were encountered or suspected in several of the acute toxicity studies with TM. However, the exceptionally low aquatic EECs indicate that uncertainty associated with the bioavailability

of TM in acute toxicity

studies is not likely

to affect the aquatic risk conclusions , since aquatic RQs are two or more orders of magnitude below acute risk LOCs. The chronic toxicity database for TM effects on fish is also uncertain. Specifically , the existing data support a NOAEC of <12 ug ai/L for freshwater fish and no data are available for saltwater fish. Again, h owever, the low chronic EECs of TM from the proposed seed treatment uses combined with the available toxicity

information for freshwater fish suggests that additional data on the chronic toxicity to fish would not materially affect the risk assessment conclusions for the proposed seed treatment uses. Although data are limited for aquatic plants and unavailable for terrestrial plants , the low aquatic EECs combined with data for similar OP pesticides suggest a low potential for TM to adversel y affect aquatic or terrestrial plants. Therefore, the need for additional data on the effects of TM on aquatic or terrestrial plants is deemed a low priority for the proposed seed treatment uses. 

## II. **PROBLEM FORMULATION**  **A. Stressor Source and Distribution** 

**1. Stressor Of concern**  As discussed further in **III.B ,**  the stressor of concern for TM defined in this assessment is the parent TM and unidentified bound residues . Multi degradation products, including oxons, were not included, as part of the stressor, based on the following reasons :  The only

major degradate identified was DM - TM, which is practically non - toxic to aquatic life and therefore not of toxicological concern ;  Terrestrial exposure modeling for seed treatment us es does not consider degradation ;  All o ther identifiable degradates were considered minor (<10%) in the presence of biotic processes ;  Although oxons were identified in fate studies, these were present in minor amounts and were not persistent. No toxicity d ata were available for oxons, but a sensitivity anal ys is indicates that even if oxons were 100X more toxic than parent TM, no aquatic risk concerns would be identified given the very low EECs for the parent and even lower EECs for the oxon degradate . B ound residues are included as part of the stressor because fate studies indicate these unidentified bound residues form in significant quantities , especiall y in aerobic soil/aquatic sy stems. Observed concentrations in aerobic soil/aquatic sy stems ranged fr om 21 - 64% (90 th 

### percentile= 51%, n=14) and in anaerobic soil was 4.1% in one soil, 31 - 39% in two soils and 2.5% in one anaerobic aquatic sy stem. In absence of toxicity data for bound residues, they are assumed of equal toxicity as parent TM .**11** 

### 2. **Source and Intensity**  TM is formulated as a flowable fungicide for seed treatment only . The rate of application for TM ranges from a minimum one time rate of 0.01lb a.i/100 lbs of seeds ( cwt) for most use patterns to a maxi mum one time rate of 0.05 lb a.i/100 lbs of seeds ( cwt) for cotton and root vegetables. When the maximum amount of seed needed to plant an acre of land is considered, the application rates vary widel y from 0.00003 lb a.i/A for cauliflower seeds to 0.04257lb a.i/A for bean seeds. Seeds treated with this chemical are the source of the stressor noting that no drift is expected to result from planting treated seeds (the potential drift of fugitive dust “dust - off” from abraded treated seed coat is possible but was not considered quantitatively in the this assessment due to lack of appropriate exposure models for this pathway). Although the chemical will be buried with the seeds, partition ing into the air may not be excluded because of the relativel y high vapor pressure (VP= 1.38 x 10 - 5 

### torr) and Henry’s Law constant (HLC= 3.68 x 10 - 6 

### atm m 3 

### mole - 1 

### ). Environmental exposure resulting from volatility is expected to reduce modeled aquatic concentrations and be a source of terrestrial exposure. Both issues will be addressed later in this assessment. **3. Physicochemical, Fate, and Transport Properties**  TM is characterized b y a water solubility of 0.7 - 1.1 ppm depending on temperature. As discussed in the preceding section, the chemical has the potential for volatilization from dry and wet surfaces. In the laboratory , TM was slightly affected by

hydroly sis (t 1⁄2 

### = 51, 61, and 62 day s at pH values of 5, 7, and 9, respectively) and showed high persistence to ph otoly sis in water and on soil. Degradates forming as a result of abiotic degradation included: DM - TM (major in photoly sis/hydrol ys is), TMO (major in hydrol ys is/minor in photolysis), and ph - CH 3 

### (minor in photoly sis/hydrol ys is). In contrast to abiotic routes of degradation (photoly sis/hydrol ys is), TM shows relativel y lower persistence to biotic degradation in the a erobic soil sy stems ( 90 th 

### percentile t 1⁄2 

### for TM alone was 40 day s in aerobic soil within a range of 16 - 79 day s) and in anaerobic soil (t 1⁄2 

### = 34 - 87 day s) and in aerobic/anaerobic water sediment s ystems (t 1⁄2 

### = 19 - 26 day s/47 days). Biotic degradation in various s ys tems resulted in the initial formation of degradates stated above, for abiotic s ys tems, including SM - TM and TM - COOH in addition to the major proce ss of mineralization to CO 2 

### ( **Figure 1**  ). Further transformation of degradates listed in **Figure 1**  resulted in the formation of low concentration of many minor degradates by biologicall y induced oxidation and cleavage . Most of the degradation products of this chemical show decline following maximum form ation suggesting that most are non - persistent. Furthermore, one of the major processes in the degradation of this chemical is the formation of large quantities of (quantified but unidentified) bound residues that showed relativel y high resistance to degradation. These bound residues, along with the parent, are considered in this assessment to be residues of concern, and when half lives are calculated with the inclusion of bound residues and parent, half - lives are in the range of 98 to 239 day s, with an up per 90 th**12**



### percentile bound on the mean half - life of 171 days ( 90 th 

### percentile t 1⁄2 

### for TM alone was 40 day s in aerobic soil within a range of 16 - 79 day s)

**Parent TM (1) Abiotic/Biotic Transformation** 

**D M**  **- TM**  **:** O - 2,6 - Dichloro - p - tolyl O - hydrogen, O - methyl phosphorothioate ( Cleavage of P - methyl moiety) **ph -**  **CH 3**  : 2, - 6 - Dichloro - 4 - methylphenol ( Cleavage of P - O - aryl mo iety) ;

**TM O (Oxon):**  2,6 - Dichloro - 4 - methyl - phenyl) dimethyl

phosphate (Oxidation: P - S to P - O) **DM -**  **TM O (Oxon):**  (2,6 - Dichloro - 4 - methyl - phenyl) methyl hydrogen phosphate (Oxidation: P - S to P - O) **(2) Biotic Transform ation Only** 

**SM -**  **TM :**  O,S - dimethyl O - 2,6 - dichloro - 4 - me thyl phenyl phosphorothioate (Sulfur substitution @ aryl methyl group) **TM -**  **COOH:** O,O - Dimethyl O - 2,6 - dichloro - 4 - carboxphenyl phosphorothioate (Oxidation @ aryl methyl group) 

### Figure **1 Degradates of TM resulting from abiotic**  **and biotic transformation in a erobic/**  **anaerobic soil and aquatic systems.**

**4. Pesticide**  **Type, Class, and Mode of Action (MOA)**  TM is a fungicide that belongs to the organophosphorus (OP) class of pesticides. Although this pesticide class is mostly

associated with insecticides, TM is practicall y non - toxic to bees on an acute contact exposure basis . Furthermore, numerous studies of cholinesterase inhibition in mammalian studies indicate TM has low activity relative to other OP pesticides and exhibits low acute toxicity

to mammals and b irds ( **Section III.C** ).**13**



### According to the Fungicide Resistance Action Committee (FRAC), 3 

### TM affects lipid sy nthesis and membrane integrity

via lipid peroxidation (proposed MOA). According to the EU 2005 Draft Assessment Report (DAR), 4 

### TM inhibits the mobili ty of zoospores of phycom yc etous fungi and may

achieve its fungicidal properties via disturbance of normal cy tokinesis similar to the compound cy

tochalasin A. TM is also considered non - sy stemic in plants, according to the EU DAR and submitted plant metabo lism studies .

**5. Overview of Pesticide Usage**  TM is a new pesticide that is proposed for use in prevent ing and/or control ling certain fungal diseases on seeds for many major crops . T herefore it is proposed as a se ed treatment , in most agricultural areas of the US . In addition treated seeds will be used in nurseries and greenhouses. **B. Receptors** 

**1. Ecological**  **Effects** Ecological measures of effect for this screening - level risk assessment are based on a suite of registrant - submitted toxicity studies performed on a limited number of organisms in broad groupings. **Table 1**  gives examples of taxonomic groups and test species evaluated for ecological effects in this screening level risk assessment. Within each of these very broad taxonomic groups, an acute and/or chronic endpoint is selected from the avai lable test data (see **Table 2**  ). A complete discussion of all toxicity data available for this risk assessment and the resulting measures of effect sele cted for each taxonomic group are included in **Appendix D** . **Table 1**  **. Taxonomic groups and test species evaluated for ecological effects in this screening**  **- level**  **risk assessment Taxonomic group**  **Representative species** Birds a Mallard duck ( Anas platyrhynchos ) Bobwhite quail ( Colinus virginianus ) Ring -Necked Pheasant (Phasianus colchicus ) Zebra finch ( Taeniopygia guttata ) Mammals Laboratory rat (Rattus norvegicus ) Mouse (Mus musculus) Beagle dog (Canis lupus familiaris) Terrestrial Invertebrates Honeybee ( Apis mellifera ) Freshwater fish b Bluegill sunfish ( Lepomis macrochirus ) Rainbow trout ( Oncorhynchus mykiss ) Guppy (Poecilia reticulata ) Fathead minnow (Pimephales promelas ) Carp ( Cyprinus carpio ) Japanese medaka ( Oryzias latipes ) 3 FRAC. 2012. FRAC Code List ©*2012: Fungicides sorted by mode of action . http://www.frac.info/frac/publication/anhang/FRAC - Code - List2011 - final.pdf 4 http://dar.efsa.europa.eu/dar - web/provision**14**

**Table 1**  **. Taxonomic groups and test species evaluated for ecological effects in this screening**  **- level**  **risk assessment Taxonomic group**  **Representative species** Freshwater Invertebrates Water flea ( Daphnia magna ) Estuarine/marine Fish Sheepshead minnow ( Cyprinodon variegatus ) Estuarine/marine Mollusk Eastern oyster ( Crassostrea virginica ) Estuarine/marine Invertebrates My sid shrimp ( Americamysis bahia ) Benthic Freshwater Invertebrates Amphipod (Hyalella azteca ) Freshwater midge ( Chironomus riparius) Benthic Estuarine/Marine Invertebrates Amphipod ( Leptocheirus plumulosus ) Aquatic Plants and Algae Green algae ( Scenedesmus quadricauda )

a Birds may be surrogates for amphibians (terrestrial phase) and reptiles. b Freshwater fish may be surrogates for aquatic phase amphibians. 

### For screening - level risk assessments, the following toxicity endpoints presented in **Table 2**  are used as inputs to the risk quotient (RQ) method for expressing risk (US EPA, 2004). The designation of “listed species” refers to either fede rally threatened or endangered species. **Table 2**  **. Toxicity endpoints used in risk quotient calculations Taxonomic group**  **Representative species** Aquatic Animals Ac ute assessment Chronic assessment Lo west tested EC 50 or LC 50 fo r freshwater fish and invertebrates and estuarine/marine fish and invertebrates acute toxicity tests. Lo west no - observed - adverse - effects - concentration (NOAEC) for freshwater fish and invertebrates and estuarine/marine fish and invertebrates early life - stage or full life - cycle tests. Terrestrial Animals Ac ute avian assessment Chronic avian assessment Ac ute mammalian assessment Chronic mammalian assessment Lo west LD 50 (single oral dose) and LC 50 (subacute dietary). Lo west NOAEC for 21 - we ek avian reproduction test. Lo west LD 50 from single oral dose test. Lo west NOAEC for two - generation reproduction test or chronic dietary study**15**

**Table 2**  **. Toxicity endpoints used in risk quotient calculations Taxonomic group**  **Representative species** Plants Terrestrial non - listed species Aquatic vascular and algae Terrestrial listed species Lo west EC 25 values from both seedling emergence and vegetative vigor for both monocots and dicots. Lo west EC 50 for both vascular and algae. Lo west EC 5 or NOAEC for both seedling emergence and vegetative vigor for both monocots and dicots **.** a Freshwater fish may be surrogates for amphibians (aquatic phase). b Birds may be surrogates for amphibians (terrestrial phase) and reptiles.



### a. **Aquatic Effects**  Acute and chronic laboratory and field tests on TM provide inf ormation regarding lethality , as well as sublethal measures of effect. Data are available on the technical grade active ingredient (TGAI) effects on freshwater and saltwater fish, aquatic invertebrates, aquatic nonvascular plants (green algae). No data w ere available for vascular aquatic plants. However, this data gap requirement was waived as part of a recent response to a waiver request (D393184); the waiver was granted due to the low potential for risks to aquatic plants based on a comparison of the aquatic EECs derived from the proposed seed treatment use and to plant toxicity endpoints from other OP pesticides. Uncertainty associated with lack of data for aquatic vascular plants is discussed in **Section IV.C** . **b. Terrestrial Effects**  For terrestrial effects, registrant - submitted studies on TM TGAI are available for acute, subacute, and chronic exposure to birds, and acute and chronic exposure to mammals. Additional ecological effects data for TM are available for honey bees ( Apis mellifera ). No data were submitted on the effects of TM on terrestrial plants. This data gap requirement was waived as part of a response to a waiver request (D393184); the waiver was granted on the basis of low likelihood of risk concern s to non - target terrestrial plants from the proposed seed treatment use given the low EECs and low phy totoxicity of other similar OP pesticides. Uncertainty associated with lack of data for terrestrial plants is discussed in **Section IV.C. C.**  **Ecosystems at Ri sk**  The ecos ys tems at potential risk from the proposed seed treatment use of TM are extensive in scope due to the wide geographic distribution of potential TM application sites. In general terms, terrestrial ecos ys tem s potentially at risk could include the treatment areas directly and adjacent areas that may

receive runoff. This could include the treatment area itself as well as**16**



### other cultivated fields, fencerows and hedgerows, meadows, fallow fields or grasslands, wo odlands, riparian habitats and other uncultivated areas. Aquatic ecos ys tems potentially at risk include water bodies adjacent to (or downstream from) the treatment area and might include impounded bodies such as ponds, lakes, reservoirs and wetland areas , or flowing waterway s such as streams and rivers. For uses in coastal areas, aquatic habitat also includes marine ecosy stems, including estuaries and salt marshes. **D. Assessment Endpoints**  Assessment endpoints repres ent the actual environmental value that is to be protected and are defined b y an ecological entity (species, community , or other entity) and its attributes or characteristics (US EPA, 1998). For the proposed TM uses, the ecological entities may include the following: birds, mammals, freshwater fish and invertebrates, estuarine/marine fish and invertebrates (pelagic and benthic dwelling), insects, and plants. The attributes for each of these entities may

include growth, reproduction, survival, biomass (s tanding crop for plants). For both aquatic and terrestrial animal species, direct acute and direct chronic effects are considered. Although these endpoints are measured at the individual level, they provide insight about risks at higher levels of biologic al organization (such as populations and communities). **E. Conceptual Model**  For a pesticide to pose an ecological risk, it must reach ecological receptors in biologicall y significant concentrations. An exposure pathway is the means by which a pesticide moves in the environment from a source to an ecological receptor. For an ecological pathway to be complete, it must have a source, a release mechanism, an environmental transport medium, a point of exposure for ecological receptors, and a feasible route of exposure. A conceptual model is used in this risk assessment to provide a written and visual description of the predicted relationships between TM application, potential routes of exposure, and the predicted effects for the assessment endpoint. A conceptual model co nsists of two major components: risk hy

pothesis and a conceptual diagram (USEPA, 1998). **1. Risk Hypotheses**  Risk hy potheses are specific assumptions about potential adverse effects ( i.e ., changes in assessment endpoints) and may be based on theory

and logic , empirical data, mathematical models, or probability

models (EPA 1998). For TM, the following ecological risk hy pothesis is being employed for this risk assessment:

 Given the proposed seed treatment uses of TM and its environmental fate properties, there is a likelihood of exposure to non - target terrestrial and aquatic organisms.**17**



###  When used in accordance with the label, TM results in potential adverse effects upon the survival, growth, and reproduction of non - target terrestrial and aquatic organisms.

**2. Conceptual Diagram**  Based on the preliminary iterative process of examining fate, transport and effects data, the conceptual model or the risk hy pothesis model for seed treatment is established. In establishing the diagram for the conceptual model it is necessary to go throu gh an iterative process to identify : (1) likel y stressors/exposure pathways and (2) organisms that are most relevant and applicable to this assessment. The conceptual model diagram for aquatic receptors (including piscivorous wildlife) is shown in **Figure 2**  **, Figure**  **3 , and**  **Figure 4**  . Overall exposure of TM (and bound residues) to aquatic ecos ys tems is likely

to be small due to the subsurface planting requirement on the proposed label and low appl ication rate (restricted to < 0.02 lb ai/A). However, there is some potential for TM to desorb from coated seeds during precipitation events and contaminate surrounding soil. Subsequently , erosion of contaminated soil and runoff may occur, thereby

transpo rting TM to nearb y surface waters. In addition, “drift” of abraded seed coatings (dust - off) is also a potential source of TM to offsite areas including water, as documented for other pesticides used for seed treatment ( e.g ., Krupke et al . 2012). L eaching to groundwater is considered a minor exposure route given the moderately high Koc 

### values for TM (1600 - 6100 L/kg oc 

### ; **Table 11**  ). Similarly , although TM shows some propensity to volatilize, this pathway is considered minor due to subsurface planting of seeds and low application rates. Once in surface water, the moderatel y high logarithm of the octanol - water partition coefficient (log Kow

### =3.8; **Table 4**  **)** and moderatel y high Koc 

### indicate that the compound will likely partition to benthic sediments, but retain a potential for bioaccumulation in aq uatic food webs, although primaril y through direct uptake across respiratory

membranes rather than biomagnification via the food web. The conceptual model diagrams for terrestrial receptors (excluding piscivorous wildlife) are shown in **Figure 3**  and **Figure 4**  . For terrestrial vertebrate receptors ( e .g ., birds, mammals), potential routes of exposure to TM include direct ingestion of treated seeds (assuming some spillage and/or subsurface foraging), inhalation of abraded seed coating dust, and ingestion of plants and prey

that have been contaminated wi th seed coat dust. Drift of seed coating dust is also a potential exposure route for some terrestrial invertebrates ( e.g ., bees) through direct contact. There is also a potential for TM to desorb from seeds and be taken up directly across the integument of soil - dwelling invertebrates, with subsequent exposure to consumers thereof. However, the non - sy stemic nature of TM in plants combined with its low application rate and high Koc 

### suggest that root uptake of desorbed TM will be a limited route of exposure .**18**

**Figure 2**  **. The aquatic conceptual model for seed -**  **coat application of TM to seeds of agricultural crops (dotted lines indicate unlikely routes of chemical dissipation)**  * Drift from abraded seed coatings during planting; ** Route of exposure includes only ingestion of fish and aquatic invertebrates; Blue arrows denote formof chem ical stressor **Stressor Source** 

**Receptors**

**Attribute Change**  TM Applied with Seeds

**Aquatic animals**  Invertebrates Ve rtebrates ****Piscivorous mammals**  **and birds**  **Individual or**  **ganisms** Reduced survival Reduced growth Reduced reproduction **Food chain** Reduction in algae and vascular plants Reduction in prey Modification of PCEs related to prey

a vailability **Habitat integrity**

Reduction in primary

p roductivity Reduced cover Community

change Modification of PCEs related to habitat Surface water/ Sediment Runoff

**Aquatic Animals** Invertebrates Ve rtebrates **Exposure Media**  Uptake/gills

or integument Ingestion Ingestion Atmospheric transport We t/dry deposition Soil Leaching to

Groundwater

Uptake/gills or integument **Aquatic Plants** 

Non - vascular Va scular Uptake/cell, roots, leaves **Riparian plants** (see terrestrial exposure CM) **TM & TM Bound Residues**  **TM Only**  Drift***19**



### Figure **3 .**  **The terrestrial conceptual model for seed -**  **coat application of TM to agricultural crops (excluding abraded seed coat drift; dotted lines indicate unlikely routes of chemical**  **dissipation) Stressor**  **Source**

**Attribute Change**  TM Applied with Seeds

Coated Seeds

**Te rrestrial**  **vertebrates*** **Te rrestrial**  **Inverts**

**Individual organisms**  Reduced survival Reduced growth Reduced reproduction **Food chain** Reduction in prey and food Modification of PCEs related to prey

a vailability **Habitat integrity**

Reduction in primary

productivity Reduced cover Community

change Modification of PCEs related to habitat **Te rrestrial plants**  grasses/forbs, fruit, seeds (trees, shrubs) Runoff

**Te rrestrial**  **vertebrates*** 

### Exposure **Media & Receptors**  Soil

Ingestion Ingestion Dermal uptake/Ingestion Atmospheric transport

Root uptake/contact

Wet/dry deposition

Ingestion Leaching to

Groundwater Irrigation wa ter **TM Only**  **TM & TM Bound Residues**  **TM Only** 

Ingestion

Blue arrows denote form of chem ical stressor**20**



### Figure **4 .**  **The terrestrial conceptual model for seed -**  **coat application of TM to agricultural crops via abraded seed coat drift (dotted lines indicate unlikely routes of chemical**  **dissipation) F.**  **Analysis Plan**

**1. Methods for Conducting Ecolog** **ical Risk Assessment and Identification of Data Gaps**  The primary

method used to assess risk in this screening - level assessment is the risk quotient (RQ) and follows the methods outlined in the EPA Overview Document (EPA, 2004). The RQ is the primary

risk value for the screening - level assessment and is the result of comparing measures of exposure to measures of effect. A commonly used measure of exposure is the estimated exposure concentration (EEC) and commonly used measures of effect include toxicity values such as the LD 50 

### or NOAEC. The RQ is calculated as a ratio comparing the estimated environmental concentration (EEC) to an effect level ( e.g ., LC 50 

### , LD 50 

### or NOAEC) using the effect level as a divisor. The resulting RQ is then compared to a specified level of concern (LOC), which represents a point of departure for concern. For example, if the RQ exceeds the LOC, then there is the potential for risk. In general, the higher the RQ, the more certain the potential risks. However, the risk quotients are not necessarily a true estimate of risk since there **Stressor Source** 

**Attribute Change**  **Application of TM Coated**  **Seeds**

**Te rrestrial**  **ver tebrates**  **Te rrestrial**  **invertebrates**

**Individual organisms**  Reduced survival Reduced growth Reduced reproduction **Food chain** Reduction in prey

a nd food Modification of PCEs related to prey availability **Habitat integrity** Reduction in primary

p roductivity Reduced cover Community

c hange Modification of PCEs related to habitat **Exposure Media** 

**Receptors** Dermal/Ingestion/uptake across integument Inhalation Dust/Air Ab raded Seed Coat Drift Deposition

onto soils, plants, prey **Te rrestrial** 

**Plants TM**  **& TM**  **Bound Residues**  **TM only** 

Blue arrows denote form of chem ical stressor**21**



### is no estimated probability of effect. Risk presumptions, along with the corresponding RQs and LOCs, are s ummarized in **Appendix E** . Generation of robust risk quotients is dependent on the quality of data from both fate and toxicological studies. The adequacy of the submitted data is evaluated relative to Agency guidelines. The following identified data gaps for ecological fate and toxicity endpoints result in a degree of uncertainty in evaluating the ecological risk of TM. For the ecological effects, the following data gaps were initially identified as part of the preliminary

chemical screening anal ys is (D38 8586; **Appendix C** ): 1. 850.1400: Fish Earl y- Life Stage (Saltwater fish). 2. 850.4100: Seedling Emergence, Tiers 1 and 2 3. 850.4150: Vegetative Vigor, Tiers 1 and 2 4. 850.5400: Aquatic Plant Growth, Algae (blue green, diatoms), Tiers 1 and 2 5. 850.4400: Aquatic Plant Growth, Vascular Plant, Tiers 1 and 2 6. Acute toxicity

data for oxon degradates ( e.g. , TMO, DM - TMO) For the current use, no major environmental fate data gaps are identified although some of the studies were classified as supp lemental. It is noted, however, that and the corresponding environmental chemistry

methods (ECMs) for the submitted independent laboratory validations (ILVs) need to be submitted by the registrant. In response to a waiver request submitted by the registr ant for data gaps identified above, the need for these data was considered in the context of:  the proposed use (seed treatment/subsurface incorporation)  the maximum application rate (0.02 lb a . i/A)  maximum expected aquatic and terrestrial EECs  available to xicity

data for TM (and other OP pesticides for plants). Based on these factors, EFED concluded that fulfillment of these data gaps would have a very low potential to alter the risk assessment conclusions and a waiver was granted (D393184). Regarding oxons TMO and DM - TMO , these were found to be a minor degradate in soil and aquatic compartments of the environment. Although some OP oxons may be more toxic than the parent compound, the need for oxon toxicity data for TM was waived because even if the TMO and DM - TMO oxons are assumed to be 100X more toxic than the parent, the risk to aquatic organisms would still be below levels of concern ( **Section IV. C**  **).** For terrestrial organisms, metabolism studies in mice and rat indicate rapid metabolism and excretion of orall yadministered TM into various degradates, including several oxons. Thus, acute and chronic toxicity data for mammals (and by extension, birds) would likely account for oxon formation in vivo. Importantl y, however, this waiver is conditioned on the current proposed use pattern and application rates (seed treatment only) and would be subject to modification for any additional uses proposed in the future or additional information available in future registration review . Further details of the impa ct of these data gaps on the risk assessment conclusions are provide d in **Section IV.C** .**22** 

### 2. **Measures of Exposure** Measures of exposure are estimates of exposure for a receptor determined by modeling or monitoring data. Measures of exposure for TM in this assessment are obtained from modeling efforts onl y, since this is a new chemical and national - scale monitoring data is not expected to be present. Exposure models used for this assessment include the suite of standard exposure models commonly

used in pesticide risk assessments (EPA, 2004). Generall y, aquatic exposure estimates are generated from EFED models and for seed treatment the model incorporate maximum proposed use rates, minimum seeding depth and empiricall y- de rived fate properties. For the proposed seed treatment use of TM, exposure to aquatic organisms is assumed to occur through direct contact with surface water contaminated by runoff/erosion from agricultural fields, drift from abraded seed coatings contami nated with TM, and with ground water contaminated b y leaching. Aquatic exposure concentrations for this assessment are based on EECs calculated using Tier II linked, Pesticide Root Zone Model PRZM (v3.12.2, May 2005) and EXAMS (v2.98.4.6, April, 2005). PRZM/EXAMS are fate and transport simulation models coupled together with the input shell pe5.pl (August, 2007) to generate daily exposures and 1 - in 10 year EECs. In addition, estimation of TM bioaccumulation in aquatic organisms is based on the KABAM mod el (Kow 

### (based) Aquatic Bio - a ccumulation Model, v. 1.0) and registrant submitted data on the bio - concentration factor. More information on these models can be found at this website 5 

### . It is noted at this time, that EFED does not have approved methods for quantifying surface water EECs resulting from contaminated dust (abraded seed coatings) or ground water discharge. Measures of exposure for terrestrial mammals, birds, reptiles and amphibians similarly incorporate maximum proposed use rates but rel y less o n fate properties. For TM, acute and chronic terrestrial exposure estimates from direct consumption of treated seeds are derived using the Terrestrial Residue Exposure Model (T - REX) version 1.5 (March, 2012) 6



### . As with the aquatic exposure assessment, som e aspects of the terrestrial exposure assessment cannot be addressed quantitatively

at this time. These include direct and indirect exposure to abraded seed coating dust and dermal uptake from exposure to coated seeds. Exposures via atmospheric transport /inhalation, irrigation water, and off site runoff are assumed to be negligible based on the chemical properties, use pattern, and low acute and chronic toxicity of TM to birds and mammals. It is also worth noting that T - REX makes a couple conservative a ssumptions that may overestimate exposure to avian and mammalian organisms. The first assumption is that T - REX assumes a diet of 100% treated seed. Secondl y, T - REX does not take into account incorporation or planting depth and assumes that treated seeds are to be broadcast onto a field. As described in **Section III** of this assessment, label requirements of TM require the treated seeds to be planted any where from 0.32 to 3.81 cm deep, depending on the crop. Seeds planted at these depths would theoreticall y not be as available to birds and mammals as they would if they were broadcast on a field.

5 http://www.epa.gov/oppefed1/models/water/index.htm . 6 http://www.epa.gov/oppefed1/models/terrestrial/ .**23**



### Additionally , the Screening Imbibition Program (SIP) and the Screening Tool for Inhalation Risk (STIR) were used to determine if drinking water and/or inhalation, respectively , are potentiall y significant routes of concern for terrestrial animals. Results from these models indicate that drinking water and inhalation are not likel y to be potential exposure routes of concern for the proposed seed treatment uses of TM .

**3. Measures of Effects**  Measures of ecological effects are obtained from a suite of registrant - submitted guideline studies conducted with a limited number of surrogate species. Measures of effect are based on deleterious changes in an organism as a result of chemical exposure. Functionally , measures of effect ty pically used in risk assessments include changes in survival, reproduction, or growth as determined from standard laboratory toxicity tests. The focus on these effects for quantitative risk assessment is due to their clear relationship to higher - order ecological sy stems such as populations, communities, and ecos ys tems. Although monitoring data may also be used to provide supporting lines of evidence fo r the risk characterization, monitoring data is not available for this new chemical. Commonly used laboratory- derived toxicity values include estimates of acute mortality ( such as LD 50 

### , L C 50 

### , or EC 50 

### ) and estimates of effects due to longer term, chronic exposures ( such as the NOAEC or NOAEL). In addition, effects other than survival, reproduction, and growth may be considered (such as changes in biochemical, cellular, organ - level responses), but these are typically used qualitatively to characterize risks since, in many cases, the relationship between these effects and higher - order processes is prone to more uncertainty. The latter can reflect changes seen in mortality , reproduction, or growth. In general, for a given assessment endpoint, the lowest relev ant measure of effect is used in calculating the risk quotient. **4. Measures of Ecosystem and Receptor Characteristics**  The assessment endpoints can be summarized as survival, growth, and reproduction of terrestrial and aquatic receptors to include birds, mammals, reptiles, amphibian, fish, terrestrial and aquatic invertebrates and terrestrial and aquatic plants. The response of these receptors to TM exposure is represented b y a small numb er of toxicity studies on representative or surrogate species. Hence, there is considerable uncertainty regarding the response of a receptor since data for all species potentiall y exposed are not available. The lowest available measure of effect for a gi ven assessment endpoint is used to calculate risk to accommodate for some of this inherent uncertainty. The ecos ys tems selected for modeling using PRZM/EXAMS aquatic assessment and T - REX for the terrestrial animal assessment are intended to be generall y representative of any aquatic or terrestrial ecos ys tem associated with areas where TM is used. The receptors addressed b y the aquatic and terrestrial risk assessments for TM are summarized in **Table 1**  . For aquatic assessments, generally

fish and aquatic invertebrates in both freshwater and estuarine/marine environments are represented. For terrestrial assessments, three different size classes of small mammals are represented, along with five potential foraging categories (short grass, tall grass, broadleaf plants/small insects, fruits/pods/seeds/large insects, and seeds). For the two different size classes of small birds, four potential foraging categories are considered (short grass, tall**24**



### grass, broadleaf plants/small insects, and fruits/pods/seeds/large insects). In addition, data are available so that earthworms, terrestrial non - target insects, and sediment - dwelling organisms are represented. Detaile d information regarding the toxicity data available for these various classes of aquatic and terrestrial receptors is provided in the Ecological Effects Characterization section and in **Appendix D** .**25**



## III. **ANALYSIS A.**  **Use Characterization** TM is proposed to be widely used in the US as a seed treatment to prevent and/or control certain fungal diseases on many crops. The chemical is formulated alone as a flowable . **Table 3**  contains a summary

of all crops proposed to be treated with TM. **Table 3**  **. Crop use patterns and application rates for the TM new chemical registration for**  **seed treatment Table Continues into the next page**  **Crop Group 1 A: Root Vegetables (except: Burdock, Chervil; Turnip -**  **rooted; Ginseng; Horseradish; Salsify, Black; Salsify, Spanish; and Skirret; 13 Crops): Application rate: 0.04**  **9 lb a.i/cwt seed**  Beet, garden Turnip - rooted Parsnip Beet, sugar Chicory Radish Burdock, edible Parsley Radish, oriental Carrot Turnip Rutabaga Celeriac **Crop Group 3 -**  **07: Bulb Vegetables (with m any exceptions “see label” 12 Crops): Application rate:**  **0.010 lb a.i/cwt seed**  Chive Chinese, fresh leaves Leek (lady’s) Onion, Beltsville bunching Chive, fresh leaves Leek (wild) Onion, bulb Kurrat Onion Onion, fresh Leek Onion, pearl Onion, green **Crop Group 4: Leafy Vegetables (Except Brassica Vegetables) (30 Crops): Application rate: 0.0 1**  **0 lb a.i/cwt seed** Arugula (roquette) Corn salad Parsley Cardoon Cress, garden Purslane, garden Celery Cress, upland Purslane, winter Celery, Chinese Dandelion Rhubarb Celtuce Dock (sorrel) Spinach Chervil Endive (escarole) Spinach, Chinese (Amaranth) Chicory, red (radicchio) Fennel, Florence Spinach, Ne w Zealand Chrysanthemum, edible - leaved Lettuce, head and leaf Spinach, vine Chrysanthemum, garland Orach Swiss chard **Crop Group 5: Brassica (Cole) Leafy Vegetables (16 Crops): Application rate: 0.010**  **lb a.i/cwt seed** Broccoli Collards Mustard greens Broccoli cavalo Gailon Chinese Mustard spinach Broccoli raab (rapini) Kale Napa Chinese Brussels sprouts Kohlrabi Rape greens Cabbage Chinese (bok choy) Mizuna Cauliflower Mustard Chinese (gai choy) **Crop Gro up 6: Legume Vegetables (Succul**  **ent or Dried) (44 Crops): Application rate: 0.010**  **lb a.i/cwt seed 26**  **Table Continues into the next page** Bean, Lupiinus : grain lupin Bean, Vigna : adzuki bean Guar Bean, Lupiinus : sweet lupin Bean, Vigna : asparagu bean Lentil Bean, Lupiinus : white lupin Bean, Vigna : blackeyed pea Pea, Pisum: dwarf pea Bean, Lupiinus : white sweet lupin Bean, Vigna : catjang Pea, Pisum: edible - podded pea Bean, Phaseolus : field bean Bean, Vigna : Chinese longbean Pea, Pisum: English pea Bean, Phaseolus : kidney bean Bean, Vigna : cow pea Pea, Pisum: field pea Bean, Phaseolus : lima bean Bean, Vigna : crowder pea Pea, Pisum: garden pea Bean, Phaseolus : navy bean Bean, Vigna : moth bean Pea, Pisum: green pea Bean, Phaseolus : pinto bean Bean, Vigna : mung bean Pea, Pisum: snow pea Bean, Phaseolus : runner bean Bean, Vigna : rice bean Pea, Pisum: sugar snap pea Bean, Phaseolus : snap bean Bean, Vigna : southern pea Pea: Chickpea (garbanzo) Bean, Phaseolus : tepary bean Bean, Vigna : urd bean Pea: Pigeon pea Bean, Phaseolus : wax bean Bean, Vigna : yardlong bean Soy bean Bean: Broad bean (fava) Bean: Lablab bean Soy bean (immature seed) Bean: Jackbean Bean: Sword bean **Crop Group 8 -**  **10: Fruiting Vegetables (22 Crops): Application rate: 0.010**  **lb a.i/cwt seed** Cocona Martynia Sunberry Eggplant Naranjilla Tomatillo Eggplant, African nonbell pepper Tomato Eggplant, scarlet Okra Tomato, Bush Eggplant,pea Peper (bell) Tomato, currant Goji berry Peper (nonbell) Tomato, tree Groundcherry Pepino Huckleberry, garden Roselle **Crop Group 9: Cucurbit vegetables (38 Crops): Application rate: 0.010**  **lb a.i/cwt seed** Cantaloupe Melon, citron Squash, winter acorn Chayote (fruit) Melon, Muskmelon Squash, winter, butternut Cucumber Momordica spp (balsam apple) Squash, winter, hubbard Gherkin Momordica spp (balsam pear) Squash, winter, spaghetti Gourd, edible (Chinese okra) Momordica spp (bittermelon) Squash, winter,calabaza Gourd, edible (cucuzza) Momordica spp (Chinese cucumber) Watermelon Gourd, edible (hechima) Pum pkin Waxgourd, Chinese (Preserving melon) Gourd, edible (hyotan) Squash, summer **Crop Group 15: Cereal Grains (except rice and wild rice; 11 Crops): Application rate: 0.010**  **lb a.i/cwt seed** Barley Millet, proso Sorghum (milo) Buckwheat Oats Teosinte Corn Corn (popcorn) Wheat (triticale) Millet, pearl Rye **Crop Group 17: Grass, Forage, Fodder, and Hay: Application rate: 0.009773 lb a.i/cwt seed**  Grass, any grass Grass, pasture and range grasses grown for silage or hay.**27 Table Continues into the next page**  **Crop Group 18: Non -**  **Grass anim al Feeds (Forage, Fodder, Straw, and Hay); (12 Crops): Application rate:**  **0.010 lb**  **a.i/cwt seed** Alfalfa Kudzu Trefoil Bean, velvet Lespedeza Vetch Clover: Melilotus Lupin Vetch, crown Clover: Trifolium Sainfoin Vetch, milk **Crop Group 19: Herbs and Spices (69 Crops): Application rate: 0.009773 lb a.i/cwt seed** Allspice Cinnoamon Nasturtium Angelica Clary Nutmeg Anise Clove buds Parsley (dried) Anise, star Costmary Peenyroyal Annatto (seed) Culantro, leaf Peper, w hite Balm Culantro, seed Pepper, black Basil Cumin Poppy (seed) Borage Curry (leaf) Rosemary Burnet Dill (dillweed) Rue Camomile Dill (seed) Saffron Caper buds Fennel (common) Sage Caraway Fennel Florence (seed) Savory, summer and winter Caraway, black Fenugreek Star Cardamom Grains of Paradise Sweet bay Cassia bark Horehound Tansy Cassia buds Hy ssop Tarragon Catnip Juniper berry Thyme Celery seed Lavender Vanilla chamomile Lemongrass Wintergreen Chervil (dried) Lovage (leaf) Woodruff Chive Lovage (seed) Wormwood Chive, Chinese Mace Cilantro or coriander, leaf Marigold, marjoram Cilantro or coriander, seed Mustard (seed) **Crop Group 20: Oilseeds (Crop Group 20, except cotton; 31 Crops): Application rate: 0.010**  **lb a.i/cwt seed** Borage Jojoba Rosehip Calendula Lesquerella Safflower Castor oil plant Lunaria Sesame Chinese tallowtree Meadow foam Stokes aster Crambe Milkweed Sunflower Cuphea Mustard seed Sweet rocket Echium Mustard: hare’s ear mustard Tallowwood**28 Table Continues into the next page**  Euphorbia Niger seed Tea oil plant Evening primrose Oil radish Vernonia Flax seed Poppy seed Gold of Pleasure Rapeseed **Cotton: Application rate: 0.04 9**  **lb a.i/cwt seed Conifers: Application rate:**  **0.010 lb a.i/cwt seed (Note:**  X - mass trees are conifers or pine) **Ornam ental Flowers: Application rate:**  **0.010 lb a.i/cwt seed** **29**



### B. **Exposure Characterization** In this section, the phy sical/chemical and laboratory fate and transport properties (mobility) of the chemical will be discussed. The chemical is of low solubility, semi volatile. TM is stable to photoly sis on soil, almost stab le to photoly sis in water (t 1⁄2 

### = 153 day s) and slightly affected by hydrol ys is (t 1⁄2 

### = 62 day s). Inaerobic soil and aquatic sy stems , the chemical is moderatel y persistent (t 1⁄2 

### range= 16 - 79 day s ; n=10 in aerobic soil and t 1⁄2 

### range= 18 - 26 day s in aerobic aquatic sy stem s; n=2 ) . Incontrast to aerobic s ys tems , TM is slightly more persistent (t 1⁄2 

### range= 34 - 87 day s n=3 in anaerobic soil and t 1⁄2 

### = 47 day s in anaerobic aquatic s ys tems; n=1). In all of these laboratory

s ys tems, three major important processes were found to affect the chemical, namely : mineralization to CO 2 

### , formation of persistent un - identified bound residues and degradation into few major to minor degradates and many very minor degradates. The major/ minor degradates include DM - TM (mostly a major degradate) , DC - ph - CH 3 

### (mostly a major degradate) , ph - CH 3 

### (mostly a minor degradate), and oxons including DM - TMO and TMO (minor degradates). All of these degradation products were observed in all systems and show decline to low levels and in most cases reac h levels that we re below the limit of detection. Finally , this section includes a summary of expected degradation pathway for TM in soil and aquatic s ys tems. Degradation p athway was used to identify

relevant residues of concern (parent + bound residues) b ased on expected exposure concentrations and toxicities. Itis noted that a summary of all environmental fate studies is provided in **Appendix G. 30**  

### 1. **Environmental Fate and Transport Characterization a.**  **Physical and chemical properties** The phy sical and chemical properties of TM are summarized in **Table 4**  . **Table 4**  **. Physical and chemical properties of TM**  **Property Description or Value**  **Reference (MRID Or Others)** CAS name O - (2,6 - dichloro - 4 - methylphenyl) O , O - dimethyl phosphorothioate Registrant Data IUPAC name O - 2,6 - dichloro - p - tolyl O , O - dimethyl phosphorothioate Molecular formula C 9 H 11 Cl 2 O 3 PS Molecular weight 301.12 g/mol CAS number 57018 - 04 - 9 PC code 128905 EPA Solubility **Water: 1.10 ± 0.08**  **ppm** @ 25 ̊ C **0.708 ± 0.06**  **ppm** @ 20 ̊ C **(**pH 7 to 7.5) **Solvents: 476 x 10**  **3 ppm**  in acetone;

**343 x 10 3**  **ppm** in xylene **; 20 x 10**  **3 ppm**  in n - hexane **;** and **38 x 10 3**  **ppm** in methanol Water FAO **1** and 483419 - 14 Respectively Solvents Footprint**2** Vapor pressure **1.38 x 10 -**  **5 torr**  @ 24.8 °C (Percent deviation= 15%); 417018 - 01 Henry’s la w constant **3.68 x 10 -**  **6** atm m 3 mole - 1 Calculated from value at 20 °C (483419 - 01) **3** UV/Visible spectra (190 to 700 nm) @ pH 7.2 and 25 ̊

C Absorption spectra shows very limited absorption in the visible

range (>300 - 400 nm) with absorption limited to the 190 - 300 nm range. Peak absorption was at 215.5 nm (wide peak) with lower absorption at 275.0 and 282.5 (narrower peaks with height of ≈ 22 and 24%, respectively, of the peak absorption at 215.5 nm) 483419 - 12

Stability in air **t1⁄2= 5.3 hours** 483419 - 45 (Calculated) using Atkinson method Kow **6,310** (Log Kow = 3.8) @ 25 o C (483419 - 13) **4 1**  FAO (visited 01/21/12): http://www.fao.org/ag/AGP/AGPP/Pesticid/JMPR/Download/94_eva/tolclofo.pdf **2** Footprint (visited 01/21/12): http://sitem.herts.ac.uk/aeru/footprint/en/index.htm **3** Calculated from a value that was calculated by the registrant ( MRID 483419 - 01) to equal 3.73 10 - 1 Pa m3 mo le - 1 Or 3.68 x 10 - 6 atm m 3 mo le - 1 @ 20 °C ( 48341901; c alculation was based on molecular weight, vapor pressure = 8.77 x 10 - 4 Pa ( MRID 483419 - 15. Or 6.58x 10 - torr at @ 20 °C and solubility= 0.708 ppm (MRID 483419 - 14) **4** Estimated by Liquid Chromatography, noting that a value of 3 6,308 (Log Kow = 4.56) @ 25 o C wa s reported, by the registrant earlier 

### The chemical is characterized by a low water solubility

of nearly 1 ppm in neutral conditions. The chemical has relatively high to moderate potential for volatilization from dry and wet surfaces. Therefore relatively high partitioning to the air is expected and the amount that partitions into the air is expected to degrade rather quickly (t 1⁄2 

### = 5.3 hours) presumabl y b y reacting with h ydrox ylradicals in the troposphere.**31**



### As stated previousl y, the measured vapor pressure for TM is 1.38x 10 - 5 

### torr (MRID 417018 - 01) and the calculated Henry’s law constant is 3.68 x 10 - 6 

### atm m 3 

### mole - 1 

### . This suggests that the chemical is semi volatile from wet/dry surfaces. Volatility

was also confirmed by

the presence of relati vel y high amounts of volatile organics in the traps for volatile organics connected to some aerobic soil/aquatic experiments ( **Table 5**  ). **Table 5**  **. Maximum quantities of organic volatiles found in different biotic studies** (ED= Experimental duration in days; ED= Experiment duration in days; T= Incubation temperature in o C; and AR= Application rate ppm) **System MRID Number**  **ED T**  **AR Maximum Volatilized Organics (Type of Trap Used)**  **1 Aerobic Soil 1** 

001561 - 06 180 25 20 19.6% @ 180 d **Aerobic Soil 2** 28.6% @ 180 d **Aerobic/Sterilized Soil (1s)** 30 0.2% @ 30 d **Aerobic/Sterilized Soil (2s)**  0.4% @ 30 d **Aerobic Soil 3** 427032 - 01 365 25 16 A total of 26% @ 365 d (18% Parent , 6% ME - ph CH 3 and 2% ph - CH 3 ) **Aerobic Soil 4** 483419 - 23 Supplemented W/483419 - 25 112 10 2.0 max= 0.22% @ 112 d (E thanediol trap) **Aerobic Soil 5** max= 0.21% @ 112 d (E thanediol trap) **Aerobic Soil 6** max= 0.22% @ 112 d (E thanediol trap) **Aerobic Soil 7, 8, 9 & 10** 483419 - 24 90 20 2.0 A total of 0.2 to 0.4% @ varied times from 3 to 90 d **Anaerobic Soil 1** 001561 - 06 60 25 20 0.6% @ 60 d **Anaerobic Soil 2** 1.1% @ 60 d **Aerobic Aquatic Syst. 1** 483419 - 26 100 20 0.67 A total of 12.7 to 11.6% @ 62 - 100 d (Parent >95%) (E thanediol + 2% paraffin/ xylene trap) **Aerobic Aquatic Syst. 2** A total of 21.8% @ 00 d (Parent >95%) **Anaerobic Aquatic Syst. 3** 431281 - 01 364 25 16.5 A total of 2.5% @ 32 d (mostly Parent) **1 Maximum Volatilized Organics= As % of the applied radioactivity (Type of Trap Used=**  Ty pe of trap used was ethylene glycol except as indicated) 

### Based on data summarized in **Table 5**  , above, the following can be concluded: (a) Volatile organics ranged from 13 to 29% in traps associated with aerobic soils 1 - 3 and aerobic aquatic s ys tems 1 & 2; noting the traps used either eth yl ene gl ycol or e thanediol + 2% paraffin/x yl ene; (b) Volatile organics ranged from 0.21 to 0.22% in traps associated with aerobic soils 1s, 2s, and 4 - 5; noting the traps used ethylene gl ycol; (c) Volatile organics were < 1% in traps associated with aerobic soils and 7 - 10; noting the traps used e thanediol and ethylene glycol, respectivel y; (d) Volatile organics ranged from 1 to 3% in traps associated with anaerobic soils/aquatic sy stems; noting the traps used ethylene gl ycol; and**32** H H H H H H

H H H O O P S O Cl

Cl 

# *

* Radiolabel Position 

### (e) Trapped organics were mostly parent and volatile degradates (Me - ph - CH 3 

### and ph - CH 3 

### ). The above conclusions suggest parent and degradates Me - ph - CH 3 

### and ph - CH 3 

### are expected to volatilize from some aerobic soils and from aerobic aquatic s ys tems. However, volatility appears to be restricted in other aerobic soils ( i.e ., soils 4 to 10), especially if it is assumed that **e** thanediol alone is effective in trapping volatile organics compared to ethyl ene glycol. In contrast, volatility appears to be restricted in anaerobic soils (n=2) and aquatic s ys tems (n=1); noting that the number of s ys tems examined were onl y three and more sy stems need to be examined to support this conclusion . Expected effects of volatility on exposure will be discussed later as it will be affected b y TM use pattern. TM is applied in association with seeds that would be planted at depths 0.32 to 3.81 cm; broadcast of treated seeds is not allowed as per the label. Finally , the n - octanol water partition coefficient (Kow

### ) of TM is 6,310 (log Kow

### =3.8) suggesting a potential for bio - concentration in aquatic organisms such as fish.

**c. Fate and Transport Propertie**  **s** The fate and transport behaviour of TM has been investigated in a series of laboratory and field studies. L aboratory

studies were all conducted with 14 

### C - labelled active substance uniforml y labelled in the phenylring ( **Figure 5**  

### ).

**Figure 5**  **. Position of radiolabel for TM used in fate and transport studies Abiotic Degradation**  

### TM labeled at the [phenyl 14 

### C] was used in conducting h ydrol ys is and photoly sis studies. Data are summarized in **Table 6**  and show that the chemical is slightly affected by

hydrol ys is (t 1⁄2 

### = 61 day s @ pH 7) with main degradation products being DM - TM and TMO (major degradates) and pH - CH 3 

### (a minor degradate) (MRID 4 17147 - 01) . Photolysis in water ( **t** 1⁄2 

### = 153 day s **)** 

### and on soil (stable) is not expected to be important processes for TM dissipation in the environment.**33**

**Table 6**  **. F**  **ate properties of TM in abiotic systems Property**  **, Description or Value,**  **and Study References (1) Hydrolysis**  (MRIDs 417147 - 01 and 483419 - 21; respectively are both “Acceptable”) **t 1⁄2**  **= 61 days**  @ pH 7; **51 days** @ pH 5; **62 days** @ pH 9@ initial concentration of 0.11 ppm and 25 o C for 30 days **Major degradates @ pH 7: Minor degradates @pH 7:**  **DM -**  **TM :**  max= 16% @ 30 days **ph -**  **CH 3**  **:** max= 0.4% @ 30 days **TM O:**  max= 12% @ 30 days Experiment conducted at high temperatures (50, 62 & 74 o C ) shows that the chemical was highly unstable at these temperatures and that it degrades into two main degradates **DM -**  **TM** and **ph -**  **CH 3**  (MRID 483419 - 21) **(2) Aqueous photolysis** (MRID 414229 - 02; “Acceptable”) **t 1⁄2**  **= 153 days**  @ pH 7 (corrected for dark control and for 12 hr/12hr cycle) **Major degradates:** Maximum in Irradiated Samples Maximum in Dark Control Samples **DM -**  **TM** 12.6% @ 30 d 7.3% @ 21 d declined to 5.4% @ 30 d **Minor degradates: ph**  **- CH**  **3 , DM**  **- TM**  **O, TMO & TM -**  **SCH 3**  0.2 - 1.3% @ 30 d Not determined - 1.5% @ 30 d Other un - identified degradates (total) 11.1% @ 30 d 7.3% @ 21 d declined to 5.4% @ 30 d **CO 2**  <0.1% @ 30 d <0.1% @ 30 d **Others: Organic volatiles:**  None **(3) Soil photolysis** (MRID 425360 - 01; “Acceptable”) **Stable** (The chemical degraded faster in the dark than when irradiated on a sandy loam soil from Tulare county at a rate of 16 lbs a.i/A and 25 o C for 30 days (Soil 70% sand, 18% silt, 12% clay, 7 meq/100g CEC, 1.32% organic matter, and pH 7.1) **Light source:** Natur al sunlight in Richmond, California at latitude 37.45N, longitude 122.26W. **Major degradates:** None **Minor degradates:** Maximum in Irradiated Samples Maximum in Dark Control Samples **SM -**  **TM** 6.2% @ 30 d 2.5% @ 30 d **DM -**  **SM -**  **TM** 1.0% @ 25 d decreased to 0.2% @ 30 d 7.6% @ 30 d Other un - identified degradates (total) 3.4% @ 30 d 2.7% @ 25 - 30 d **CO 2**  max= 1.1% @ 30 d max= 1.1% @ 30 d **Others: Organic volatiles:**  No significant amount detected; **Bound residues:** max 6.40% @ 25 days declining to % 3.8% @ 30 days (irradiated samples) compared to a max of 1.5% @ 18 days declining to % 1.1% @ 30 days (dark control samples) 

### Biotic Degradation Biotic degradation was investigated in the laboratory in eleven soils and three aquatic s ys tems and in five field soils in GA, OH, CA, LA and MO. Characteristics for these systems are s ummarized in **Table 7**  .**34**

**Table 7**  Available data for characteristics of soil and aquatic systems used in laboratory biotic studies. **Designation System Characteristics**  **Soil 1** Sapporo clay loam f rom J apan (Allophane clay mineral) incubated for 180 days and 30 days when sterilized @ 25 o C (A

pplication rate 20 ppm). The s oil is characterized by 4 8% sand, 28% silt, 24% clay, 39 meq/100g CEC, 11.6% OM, and pH 5.3 **( MRID 001561**  **- 06)**  **Soil 2** Az uchi sandy clay loam from Japan (kaolinitic) incubated for 180 day s and 30 day s when satirized @

25 o C (Application rate 20 ppm). The s oil is characterized by 62.5% sand, 17% silt, 20.5% clay, 39 meq/100g CEC, 0.4% OM, and pH 5.5 **( MRID 001561**  **- 06)**  **Soil 3** A sandy loam soil from Tulare county, CA incubated for 365 days @ 25 o C (Application rate 16 ppm=

equivalent to 32 lbs a.i/A to a depth of 6”). The s oil is characterized by 70% sand, 18% silt, 12% clay , 7 meq/100g CEC, 0.8% OM, and pH 7.1) **( MRIDs:**  **427032 -**  **01, 428183**  **- 01**  **) Soil 4**  Sandy loam from the UK (Abington; pH 7.7 and OM 2.6% **( MRID**  **483419 -**  **23 supplem**  **ented by** 

**483419 -**  **25) Soil 5**  Loamy sand from the UK (Shuttle worth; pH 6.0 and OM 2.4%) **( MRID**  **483419 -**  **23 s**  **upple mented** 

**by 483419 -**  **25) Soil 6**  Silt loam from the UK (Terling; pH 5.2 and OM 4.6%) **( MRID 483419**  **- 23 supplemented by 483419**  **-**

**25) Soil 7**  Sandy loam from the UK (PT - 102): pH 6.9 - 7.1 and OM 4.3% **( MRID 483419**  **- 24)**  **Soil 8** Sandy loam f rom the UK (PT - 103; sand 75%, 12% silt, 13% clay; pH 4.1 - 5 .5; CEC= 6.1 meq/100 g; and OM 2.1 - 2.4%) **(M RIDs 483419**  **- 22 for DM**  **- TM**  **; 483419**  **- 24)**  **Soil 9** Clay loam from the UK (SK 15556090): pH 6.2 - 6.7 and OM 7.8% **( MRID 483419**  **- 24)**  **Soil 10** Clay loam from the UK (SK 960087): pH 7.2 - 8.0 and OM 4.7% **( MRID 483419**  **- 24)**  **Soil 11**  Sandy loam f rom the UK (SK 108672; sand 20%, 53% silt, 27% clay; pH 6.0 - 6.2; CEC= 20.0 meq/100 g; and OM 5.2%) **(M RIDs 483419**  **- 22 for DM**  **- TM**  **) Soil 12**  Sandy loam f rom the UK (SK 920191; sand 36%, 29% silt, 35% clay; pH 7.5 - 8.1; CEC= 31.0 meq/100 g; and OM 3.4%) **(MRIDs 483419 -**  **22 for DM -**  **TM )**  **System 1**  Pond water: pH=7.9 and sandy silt loam s ediment from the UK: pH 6.9 - 7.2, CEC 29.8 meq/100g and OM 12.7% **(M RID 483419**  **- 26)**  **System 2**  Lake water: pH=6.6and sandy loam sediment from the UK: pH 5.7 - 6.1, CEC 16.2 meq/100g and OM

5.8% **(M RID 483419**  **- 26)**  **System 3**  Soil/water: sandy loam soil: water incubated for 364 days @ 25 o C. The soil is sandy loam from Tulare

county, CA (A

pplication rate 16.5 ppm). The s oil is Soil 3 (see above) **(M RID 431281**  **- 01**  **)** Abbreviations: OM= Organic Matter; CEC= Cation exchange capacity 

### Environmental fate data are summarized in **Table 8**  . 

### Data include results obtained from studies submitted for laboratory

degradation: aerobic/anaerobic soil and water/sediment sy stems, field dissipation in terrestrial systems, and fish bio - con centration. A summary of these studies is also included in **Appendix G** . As shown in **Table 8**  , aerobic degradation in soil and aquatic s ys tems is a resul t of three major processes: mineralization to CO 2 

### , formation of bound residues followed, in importance, b y degradation into few major to minor degradates and many minor degradates (usually <1% each). The degradation results from oxidation of the aryl methyl group and the P=S to P=O; and cleavage of the P - methyl and P - O - aryl moieties. The major/minor degradates include **DM -**  **TM** (mostly a major degradate), **ph -**  **CH 3**  

### (mostly a minor degradate), and oxons including **DM -**  **TMO** and **TMO** (minor degradates). All of these degradation products show decline to low levels and in most cases reaching levels that were below the limit of detection. In contrast to aerobic s ys tems, degradation in anaerobic soil/aquatic sy stems is slower but produce similar degradation products in addition to the unique degradate **DC -**  **ph -**  **CH 3**  .**35**



### Bioconcentration The bioconcentration and transformation of TM was investigated using bluegill sunfish ( Lepomis macrochirus ) for 35 - day s exposure to radiolabelled TM (MRID 48737503). Bluegill were exposed to 0.001 and 0.01 mg ai/L under flow - through conditions for 35 day s followed by a depuration period of 14 day s in clean water. These exposure concentrations are ~ 0.01X and 0.001X the 96 - h LC 50 

### reported for TM with bluegill (>702 mg ai/L). Residu es in water and tissue (including various metabolites) were measured on a weekl y basis. The uptake data indicated that TM reached steady- state accumulation in fish quickly (within 3 day s of exposure initiation). TM concentrations were stable in the water , but extensive degradation occurred in the fish during the exposure phase. Major degradates included DM - TM - CH 2 

### OH, DCMP, and ph - CH 2 

### OH of which onl y DM - TM - CH 2 

### OH retained the thiophosphate ester moiety. Minor degradates included TMO and ph - COOH. The steady state BCF for total radioactive residues (TRR) was determined as 63 - 71 L/kg w.w. (edible tissue); 780 - 1054 L/kg w.w. (non edible tissue) and 384 - 506 L/kg w.w. (whole body). L ipid fraction in whole body corresponding to these BCFs ranged from 4.3 to 4.5% . Depuration of TM (and TRR) was rapid, with whole body depuration half lives ranging from 0.41 - 0.42 day s (TRR) and 0.31 - 0.38 day s (TM). An earlier study

was conducted on bioconcentration of TM in bluegill sunfish ( L . macrochirus ) using labeled TM for 28 day s followed by a 14 - day depuration period (MRID 00163642). This study is classified as “supplemental” because exposure concentrations fluctuated beyond guideline recommendations and degradates were not characterized in the water. Despite these limitations, BCFs were similar to the previously described study and ranged from 

### 120X (edible tissues) , 1300X (non edible tissues) and 770X (whole body). **Table 8**  **.** Fate properties of TM in biotic systems (Refer to **Table 7**  above for soil i dentification/ characteristics and to **Appendix G** for a detail s )

**Study Soil**  **Half -** **life (t1⁄2 in days)**  **Observed Maxima of degradates (% of the Applied Parent)**  **MRID Number “Classification”**  **Parent TTR**  **1**

**Aerobic soil**  **metabolism** Soil 1 48 239 Major degradates (>10%): **CO 2**  **;** and **DM -**  **TM** Minor degradates: 1 - 4%: **DM -**  **TM O;**  and **ph -**  **CH 3**  **;** <1%: **TM -**  **COOH; TM -**  **CH 2**  **OH; TMO -**  **COOH; TMO**   ** CH** **2 OH; ph**  **- COOH;**  and **ph -**  **CH 2**  **OH**

**001561 -**  **06** “Supplemental ” Soil 1 (Sterilized) **80 NC**  Major degradates (>10%): **None** Minor degradates: 1 - 3%: **ph -**  **CH 3**  **;** <1%: **DM -**  **TM; DM**   ** TM** **O; TMO; TMO -**  **COOH; TMO -**  **CH 2**  **OH; TM -**  **COOH; TM**  **- CH**  **2 OH; ph**  **- COOH; ph**  **- CH**  **2 OH;**  and **CO 2**  Soil 2 **44 210**  Major degradates (> 10%): **CO 2**  Minor degradates: 1 - 5%: **DM -**  **TM ; DM**  **- TM**  **O;** and **ph**   ** CH** **3 ;**  <1%: **TM -**  **COOH; TM -**  **CH 2**  **OH; TMO; TMO**   ** COOH; TMO** **- CH**  **2 OH; ph**  **- COOH; and ph**  **- CH**  **2 OH** **36**

**Study Soil**  **Half -** **life (t1⁄2 in days)**  **Observed Maxima of degradates (% of the Applied Parent)**  **MRID Number “Classification”**  **Parent TTR**  **1**

Soil 2 (Sterilized) **116 NC**  Major degradates (>10%): **None** Minor degradates: 1 - 3%: **DM -**  **TM ;**  and **ph -**  **CH 3**  **;** <1%: **DM -**  **TM O; TMO;**  **TM O**  **- COOH; TMO**  **- CH**  **2 OH;**  **TM -**  **COOH; TM -**  **CH 2**  **OH; ph -**  **COOH; ph -**  **COOH; ph**   ** CH** **2 OH;**  and **CO 2**  Soil 3 **79 161**  Major degradates (>10%): **CO 2**  **;** and **DM -**  **TM** Minor degradates: 1 - 3%: **ph -**  **CH 3**  **;** <1%: **DM -**  **TMO; DM**   ** TM** **O -**  **COOH; TM**  **- COOH; TM**  **- CH**  **2 OH; TMO**  **- COOH;**  **TM O**  **- CH**  **2 OH; ph**  **- COOH;**  and **SM -**  **TM 427032**  **- 01**  **“Acceptable”** Soil 4 **28 116**  Major degradates (>10%): **CO 2**  Minor degradates: 2%: **TM -**  **COOH ;**  <1%: **DM -**  **TM ;**  **DM**   ** TM** **O; TM**  **O; TM -**  **COOH; ph -**  **COOH;** and **ph -**  **CH 2**  **OH 483419**  **- 23**  **S upplemented**  **by 483419 -**  **25 “**  **Supple me**  **ntal ”**  Soil 5 **23 169**  Major degradates (>10%): **CO 2**  Minor degradates: Degradates Not Tracked Soil 6 **31 165**  Major degradates (>10%): **CO 2**  Minor degradates: Degradates Not Tracked Soil 7 **17 139**  Major degradates (>10%): **CO 2**  Minor degradates: 1%: **DM -**  **TM ;**  and **ph -**  **CH 3** 

**483419 -**  **24 “Acceptable”**  Soil 8 **16 128**  Major degradates (>10%): **CO 2**  **;** and **DM -**  **TM** Minor degradates: 8%: **ph -**  **CH 3**  Soil 9 **16 114**  Major degradates (>10%): **CO 2**  Minor degradates: 4%: **DM -**  **TM ;**  and **ph -**  **CH 3**  Soil 10 **17 98**  Major degradates (>10%): **CO 2**  Minor degradates: 4%: **ph -**  **CH 3**  <1%: **DM -**  **TM** Aerobic/ Anaerobic Soil Metabolism Soil 3:

Aerobic Phase **53 NC**  Major degradates (>10%): **DM -**  **TM** Minor degradates: 4%: **CO 2**  **;** and **ph -**  **CH 3**  **428183 -**  **01 “Acceptable”**  Soil 3: Anaerobic Phase **87 NC**  Major degradates (>10%): **DM -**  **TM** Minor degradates: 3 & 8%: **CO 2**  (3%); and **ph -**  **CH 3**  (8%)

Anaerobic Soil Metabolism Soil 1 **36 107**  Major degradates (>10%): **None** Minor degradates: 2 - 8%: **DM -**  **TM; DM**  **- TM**  **O; TMO;**  and **ph -**  **CH 3**  **;** <1%: **CO 2**  **; TM**  **O -**  **COOH; TM**  **O -**  **CH 2**  **OH; TM**  **** **COOH; ph -**  **COOH;** and **ph -**  **CH 2**  **OH 001561**  **- 06**  **“Supplemental”** Soil 2 **57 161**  Major degradates (>10%): **None** Minor degradates: 1 - 7%: **DM -**  **TM; DM**  **- TM**  **O; TM**  **O;** and **ph -**  **CH 3**  **;** <1%: **CO 2**  **; TM**  **O -**  **COOH; TM**  **O -**  **CH 2**  **OH; TM**  **** **COOH; ph -**  **COOH;** and **ph -**  **CH 2**  **OH** Aerobic Aquatic Metabolism Sy stem 1 **19 49**  Major degradates: ( 24 - 53%) : **CO 2**  **;** and **DM -**  **TM** Minor degradates: 3 - 7%: **DM -**  **TM O;**  and **ph -**  **CH 3**  **;** <1%: **TM -**  **COOH 483419**  **- 26**  **“Acceptable”** Sy stem 2 **26 65**  Major degradates: (13 - 36%) : **CO 2**  **;** and **DM -**  **TM** Minor degradates: 3 - 5%: **DM -**  **TM O;**  and **ph -**  **CH 3**  **;** <1%: **TM -**  **COOH** Anaerobic Aquatic Metabolism Sy stem 3 **47 95**  Major degradates: (10 - 58 %) : **CO 2**  **; DC**  **- ph**  **- CH**  **3 ;**  and **DM**   ** TM** Minor degradates: 5 - 8%: **ph -**  **Cresol ;**  and **ph -**  **CH 3**  **431281 -**  **01 “Acceptable”**  Aerobic Soil Metabolism Soil 8 **1.2 2**  **NC** Major degradates: (15 - 19%) : **CO 2**  **;** and **ph -**  **CH 3**  Minor degradates: 9%: **DM -**  **TM O**  **;** <1%: **ph -**  **COOH 483419**  **- 22**  **“Acceptable” 37** 

**Study Soil**  **Half -** **life (t1⁄2 in days)**  **Observed Maxima of degradates (% of the Applied Parent)**  **MRID Number “Classification”**  **Parent TTR**  **1** (Test Substance: **DM -**  **TM** ( major TM degradate **)** Soil 11 **0.6 2**  **NC** Major degradates: (13 - 23%) : **CO 2**  **;** and **ph -**  **CH 3**  Minor degradates: 6%: **DM -**  **TM O**  **;** <1%: **ph -**  **COOH** Soil 12 **0.3 2**  **NC** Major degradates: (12 - 20%) : **CO 2**  **;** and **ph -**  **CH 3**  Minor degradates: 8%: **DM -**  **TMO ;**  1%: **ph -**  **COOH** Terrestrial Field Dissipation TFD data we re submitted between April 1987 and November 1988 in support of registration of

the chemical as seed treatment and soil application on several terrestrial food and non - food crops. The chemical wa s applied to bare soil (not with treated seeds) at a significantly higher rate than expected to accom

pany treated seeds (5.5 to 24 lbs a.i/A com pared to 0.02 labs a.i/A). Therefore, results from these studies (MRIDs 001561 - 11 and 265176 - 08) are probably not relevant to the current assess me nt and are not discussed here. **001561 -**  **11 and**  **265176 -**  **08**

Fish Bioconcentra tion **Bluegill sunfish ( 35**  **- day exposure period and 14**  **- day depuration period):** 

**Max. Steady State BCFs**  **(TRR) :**  **71 x**  (edible tissues), **1054x** (non - edible tissues), and **506x** (whole fish) **Bluegill sunfish (28 -**  **day exposure period and 14 -**  **day depuration period): BCFs: 120x**  (edible tissues), **1,300x** (non - edible tissues), and **770x** (whole fish) **48737503 “**  **Acceptable ”**  **00163642 “Supplemental”** 

**1 TTR= Total Toxic Residues=**  Parent+ Bound Residues, **2 Very short half** 

**- life**  resulting from the formation of un - identified bound residues (71 - 84% of the applied radioactivity) **NC** = TTR Half

- lives were not calculated for sterilized soils and for soils with low bound residues (<5%) 

### Bound residue High percentages of bound residues were observed in most biotic degradation studies ( **Table 9**  ). These bound residues were relatively persistent and were quantified by radioactivity

as percent of applied parent but the nature of these residues were not identified. The residues were onl y characterized b y partitioning into fulvic and humic acids following harsh extraction by 0.5N NaOH. **Table 9**  **. Percentages**  **of bound residues found in different biotic studies following varied extraction procedures**  **studies (ED= Exper imental duration in days; T= Incubation temperature in**  **o C; AR=**  **Application rate ppm; and EP= Extraction Procedure Number “refer to** Error! Reference source not found. Error! Reference source not found. 

### Table **10** . **for description of the procedures”)**

**System MRID #**  **ED T**  **AR EP**  **Maximum Bound residues (% of Applied Radioactivity**  **Aerobic Soil 1** 

001561 - 06 180 25 20 **1** 53.4% @ 120 d declined 50.8% @ 180 days (d) **Aerobic Soil 2** 46.6 - 47.0% @ 120 - 180 d **Aerobic/Sterilized Soil 1** 30 19.1% @ 30 d **Aerobic/Sterilized Soil 2** 11.0% @ 30 d **Aerobic Soil 3** 427032 - 01 365 25 16 **2** 21.0% @ 271 d declining to % 19.0% @ 365 d **Aerobic Soil 4** 483419 - 23 112 10 2.0 **3** 44.0% @ 84 d declined to 41.9% @ 112 d**38**

**Aerobic Soil 5** Supplemented W/483419 - 25 61.0% @ 84 d declined to 54.5% @ 112 d **Aerobic Soil 6** 52.2% @ 112 d **Aerobic Soil 7**

483419 - 24 90 20 2.0 **4** 63.6% @ 30 d declined to % 56.1 @ 90 d; **Aerobic Soil 8** 60.2% @ 15 d declined to 49.0% @ 90 d; **Aerobic Soil 9** 55.9% @ 15 d declined to % 52.6% @ 90 d **Aerobic Soil 10** 48.9% @ 30 d declined to 45.4% @ 90 d **Aerobic Soil 8** 483419 - 22* 7 20 0.26 **5** 73.6% @ 3 d declined to 73.2% @ 7 d **Aerobic Soil 11** 78.6% @ 3 d declined to 68.6% @ 7 d **Aerobic Soil 12** 81.0% @ 0.7 d declined to 76.4% @ 7 d **Anaerobic phase (soil 3)** 428183 - 01 60 25 16 **2** 4.1% @ 60 d **Anaerobic Soil 1** 001561 - 06 60 25 20 **1** 39.0% @ 60 d **Anaerobic Soil 2** 31.0% @ 30 - 60 d **Aerobic Aquatic System 1** 483419 - 26 100 20 0.67 **4** 25.9% @ 62 d declined to 20.4% @100 d **Aerobic Aquatic System 2** 35.0% @76 d declined to 19.9% @100 d **Anaerobic Aquatic System 3** 431281 - 01 364 25 16.5 **2** 2.5% @ 32 d * Test substance in all studies is 14 C TM except for one aerobic soil study (MRID 483419 - 22) w here it was 14 C DM - TM; the major degradate of TF (Rows highlighted in light blue) 

### Five different extraction procedures were used in submitted biotic studies to extract residues from the soil and sediment . These procedures are summarized in **Table 10**  **. Table**  **10 .**  **Description of extraction procedures used in soil and sediment extraction in biotic studies (Refer to**  **Table 8**  

### for a list of these studies) **Extraction Procedure**  **(EP) Procedure Summary**  **EP 1** Once with 1 N HC1: Ethyl acetate (3:2) followed by T wo times with Ethyl acetate alone → Bound Residues **EP 2 1**  **st Extraction (Acetone/water):**  Three times with Acetone: Water 1:5 (v:v) → Bound Residues - 1

**2 nd**  **Extraction (Acetone/HCl):** Three times with Acetone: 0.5N HCl 5:1 (v:v) **→** Bound Residues - 2 **EP 3 1**  **st Extraction: used for samples Up to 7 days:** 

Soxhlet extracted with acetone : glacial acetic acid (98:2 v/v) for 18 hrs → Bound Residues **2 nd**  **Extraction: used for samples >7 day contains more than 20% of applied radioactivity:** Additional three times extraction with 0.5M HC1 5:1 (v:v), three times. **Note:** Additional recovery, from the second extraction procedure, was low **EP 4** Soxhlet extracted with acetone : glacial acetic acid (98:2 v/v) for 18 hrs → Bound Residues **EP 5** 1 st Three times with acetone:0.01M HCl (5:1, v:v) → Bound Residues

Sam ples of each soil containing the highest concentration of un - extracted residues were Soxhlet - extracted overnight using acetone: glacial acetic acid (98:2, v:v). Note: Additional recovery, from the second extraction procedure, was <1% of applied radioactivity**39**



### Data in **Table 9**  and **Table 10**  show that acetone/water and acetone/HCl was the most effective extraction procedure (refer EP 2 in **Table 9**  and **Table 10**  **)** . The maximum levels were relativel y low following EP 2 (3% in an anaerobic aquatic sy stem and 21% in an aerobic soil sy stem) compared to a higher range following EP 1 and EP 3 - 5 (a range of 26 - 35% in two aerobic aquatic s ys tems and 31 - 64% in nine aerobic soil sy stems). The result s for one soil (EP 2) , under aerobic conditions and under anaerobic conditions are also shown in **Figure 6**  which also shows the change in the levels of bound residues with time and its relative persistence after reaching its maximum formation. Data in **Figure 6**  suggest that the second extraction step in EP 2 (acetone/HCl) was able to significantl y reduce levels of the maximum bound residues from 36% following the first step (with acetone/water) to 21% following the second step (with acetone/HCl). Data on the c onstituents of the second extraction show that additional parent and degradates were extracted suggesting that insufficient extraction may result in parent and degradates being part of the bound residues. Additionally , anaerobic conditions appear to reduce the formation of bound residues ( **Figure 6**  **)** .

**Figure 6**  **. Un -**  **extracted bound residues following the most effective extraction procedure; extraction**  **procedure 2 (EP 2, Table**  **9 , above)**  

### Based on data summarized in **Table 9**  **, Table**  **10** and **Figure 6**  , the following may be concluded: (1) With the exception of EP 2, the extraction methods may have not been successful in reaching complete extraction of the unidentified/unknown bound residues. These bound residues could be parent and/or major degradate(s). (2) The un - identified bound residues are of significant quantities and show relative persistence; and (3) Relatively

low bound residues are observed in anaerobic and sterilized sy stems compared to aerobic/viable sy stems. Examples include: (a) The level of bound residues was 2.5% in anaerobic aquatic s ys tem; (b) The level bound residues in viable soil 1 was 53% compared to 19% **Bo und**  **re si** **due s**  **fo llo**  **wi ng** **tw o con** **sec ut** **ive e**  **xtr action** **s fo**  **r ae**  **ro bic**  **/an ae**  **ro bi**  **c so**  **ils (M**  **RI Ds**  **427032-01 & 428183-**  **01)**

0% 5% 10% 15% 20% 25% 30% 35% 40%

0 50 100 150 200 250 300 350 400 **Ti me**  **( date**  **s) B** **o u** **n d** **R e** **s i** **d u** **e s** **( %** **o f** **A p** **p l** **i e** **d R** **a d** **i o** **a c** **t i** **v i** **t y** **)**

Bound Re sid ue s 1 (Sol id fi ll ma rke rs :

Aer obi c; No fi ll ma rke rs : a nae ro bi c) Bound Re sid ue s 2 (Sol id fi ll ma rke rs : Aer obi c; No fi ll ma rke rs : a nae ro bi c)**40** 

### after sterilization; (c) The level bound residues in viable soil 2 were 47% compared to 11% after sterilization; and (4) The levels of bound residues were exceptionally high (74 - 81%) when DM - TM (a major degradate of TM) was used as test material. The above stated lin es of evidence indicate that aerobic parent and degradates (e.g. DM - TM) might constitute part of the unidentified/unknown bound residues (item 1 above) . Especially that the aerobic soil degradation profile for th is DM - TM degradate resulted in high concentration of bound residues (item 4 above) . Additionally the data indicates that the bound residue s are significant and relativel y persistent. Bound residues were included as part of the stressor because of the possibility

of presence of parent and degradates as part of these residues in addition to presence in significant quantities and its persistence. **Transformation Profile Figure**  **7** contains a summary of the expected transformation profile for TM in the natural environment based on laboratory studies. The degradation profile for TM shows the formation of many degradates but at relatively low concentrations. It also shows that the multi degradation products, including oxons, were not persistent as most degrade rather quickly to levels of no detection. Therefore, TM degradates are not included in the definition of the stre ssor of concern. Additionally , the very

low application rate for this chemical is expected to yield very low exposure EECs for the chemical itself and even much lower for degradates. Conservative exposure EECs for the combined parent and bound residues are chosen to represent expected exposure from parent, bound residues and degradates on the assumption that not all of the bound residues are of concern. The bound residues are included as part of the stressor because data shows that these un - identified bound residues are of significant quantities that may not be ignored. However, this assumption is considered a conservative one and is expected to yi eld relativel y conservative surface water exposure EECs.**41 TM**  **Parent**

**DM -**  **TM SM**  **- TM**  **TM O (Oxon)**  **Ph -**  **CH 3**  **TM -**  **COOH**

**DC -**  **ph -**  **CH 3**  **Me -**  **ph -**  **CH 3**  **p -**  **cresol DM**  **- TM**  **- COOH**  **ph -**  **COOH p**  **h -**  **CH 2**  **OH** Cleavage of P - O - aryl moiety Abiotic + Biotic Degradation **1** Cleavage of P - methyl moiety Abiotic + Biotic Degradation **1**

Sulfur substitution @ aryl methyl group Biotic Degradation **1** Oxidation: P - S to P - O Abiotic + Biotic Degradation **1** Oxidation @ aryl methyl group Biotic Degradation **1**

**DM -**  **TM -**  **COOH DM**  **- TM**  **O (Oxon )** 

**ph -**  **CH3 ph**  **- COOH**  **DM -**  **TM**

**DM -**  **TM O (Oxon)**  **ph -**  **CH 3**  **DM -**  **TM O (Oxon)**  **ph -**  **CH 3** 

**DC -**  **ph -**  **CH 3**  **Me -**  **ph -**  **CH 3**  **DC -**  **ph -**  **CH 3**  **(Refer to structure below)**  **Me -**  **ph -**  **CH 3**  **(Refer to structure below)**  **p -**  **cresol (Refer to structure**  **below) p**  **- cresol**  **DM -**  **TM -**  **COOH (** **Refer to structure belo w)**  **ph -**  **COOH & pH -**  **CH 2**  **OH (Refer to structure below)**  **ph -**  **COOH & pH -**  **CH 2**  **OH 42** 

**1 Abiotic Degradation**  refers to hydrolysis which appear to cause the 1 st degradation step (i.e. production of the 1 st degradate). **Biotic degradation** refers to observed degradtion in aerobic/anaerobic soil and aquatic systems. Noting that mineralization to **CO 2**  and the formation of **Bound Residues** are important processes in the biotic degradation of this chemical. **Figure 7**  Expected environmental degradation pathways for TM (degradates are color coded) 

### TM is expected to mineralize to CO 2 

### , form significant quantities of bound residues and produce many degradation products. Observed mineralization to CO 2 

### ranged from 17 to 53% while bound residues reached maxima over 50% in some soil/aquatic sy stems. Submitted fate studies show that the chemical is affected by hydroly sis with main degradation products from hydrolysis being DM - TM and TMO (major degradates) and pH - CH 3 

### (a minor degradate) (MRID 417147 - 01) . In biotic studies, hydrol ys is and biotic degradation may both occur, and TMO is a minor degradate. Aerobic and anaerobic degradation, in the soil and aquatic s ys tems, suggest degradation into: (a) Few major to minor degra dates that may be categorized into two categories, namely : i. **DM -**  **TM** (maxima= 11 - 18% in some aerobic soils and <1 - 5% in others; 13 - 24% in aerobic aquatic systems and 58% in anaerobic aquatic s ys tems) and **ph**   ** CH** **3** 

### (maxima= 1 - 8% in aerobic soil and aquatic sy stems ). It is however noted that maximum observed levels in anaerobic soil are7 - 8% for **DM -**  **TM** and 3 - 4% for **ph -**  **CH 3**  

### . In all soil/aquatic aerobic and anaerobic s ys tems both **DM -**  **TM** and **ph -**  **CH 3**  

### decline to very low level and sometimes to no detection. ii. **Oxons:** Observed o nl y in soil/aquatic systems under aerobic conditions. Oxon degradates include: **DM -**  **TMO** (observed at maximum levels ranging from <1 - 5%) and **TMO** (observed at maximum levels of ≤1%). Both oxons show a clear decline following maxima. It is therefore concluded that the formation levels of oxons are low resulting in expected low concentrations in the natural environment. iii. **DC -**  **ph -**  **CH 3**  

### : Reach maxima of 10% in anaerobic aquatic s ys tems followed by clear decline to 2%. (b) Many minor degradates with concentrations usually <1% each resulting from oxidation of the P=S to P=O or the aryl methyl group and cleavage of the P - methyl and P - O - arylmoieties. An aerobic soil study was submitted for the major degradate of TM; that is **DM -**  **TM** . Data show that **DM -**  **TM** degrades into **CO 2**  

### (maxi ma ranging from 19 - 23%), **ph -**  **CH 3**  

### (maxima ranging from 12 - 15% followed by clear decline), **DM -**  **TMO** (maxima ranging from 6 - 8% followed b y clear decline) and large amounts of un - identified bound residues (maxima ranging from 74 - 81% with no clear decline during the 7 - day experiment). The degradation profile for TM shows the formation of many degradates but at relativel y low concentrations ( **Figure 7**  ). It also shows that the multi degradation products, including oxons, were not persistent as most degrade rather quickly to levels of no detection. Therefore, TM degradates are not included i n the definition of the stressor of concern. Additionally , the very low application rate for this chemical is expected to yield very low exposure EECs for the**43**



### chemical itself and even much lower for degradates. Conservative exposure EECs for the combined parent and bound residues are chosen to represent expected exposure from parent, bound residues and degradates on the assumption that not all of the bound residues are of concern. The bound residues are included as part of the stressor because data shows that these un - identified bound residues are of significant quantities that may not be ignored. However, this assumption is considered a conservative one and is expected to yi eld relativel y conservative surface water exposure EECs. **Mobility** T he adsorption/desorption characteristics of TM were determined for six soils which varied in organic matter and clay

content (MRIDs: 422733 - 01 and 483419 - 19). Data are summarized in **Table 11**  . Based on Koc 

### values (range from 1,649 to 6 , 139 L/Kg with an average of 3,279 L/Kg ), mobility

of TM in the tested soils is classified as slightl y mobile in accordance to the FAO mobility

classification (FAO, 2000) . Therefore, moderate mobility is expected in the natural environment which limits the possibility for contaminating the ground water resources.

**Table 11**  **. Adsorption/Desorption properties of TM**  **Property /**  **Description or Value Reference (MRID**  **#) K**  **d = 7.59**  and **K oc**  **= 1,649 L/Kg** in a Sandy Loam soil from California (0.46% organic carbon, 7 meq/100g CEC and pH of 7.1) **K d** **= 25.17** and **K oc**  **= 6,139 L/Kg** in a Loamy sand soil from Kentucky (0.41% organic carbon, 4 meq/100g CEC and pH of 7.6) **K d** **= 43.96** and **K oc**  **= 3,209 L/Kg** in a Silty clay Loam soil from Kentucky (1.37% organic carbon, 18 meq/100g CEC and pH of 6.7) **K d** **= 24.03** and **K oc**  **= 3,482 L/Kg** in a Clay soil from Kentucky(0.69% organic carbon, 24 meq/100g CEC and pH of 7.3) **422733 -**  **01 “**  **Supple mental**  **” K**  **d = 32.4**  and **K oc**  **= 2,655 L/Kg** in a Loam soil from Ne w Jersey (1.2% organi c carbon, 9 meq/100g CEC and pH= 6.9) **K d** **= 16.3** and **K oc**  **= 2,541 L/Kg** in a Sand soil from Florida (0.64% organic carbon, 4 meq/100g CEC and pH = 6.1) **483419 -**  **19 “Supple**  **mental”** 

### Environmental Chemistry Methods (ECMs)/Independent Laboratory Validations (ILVs) Environmental chemistry methods (ECMs) and associated Independent laboratory validations (ILVs) for residues in soil and water are used to evaluate analy ses described in submitted environmental fate and ecological effects studies. These validated anal yt ic al methods are also used, in the future, b y various Federal, State, Tribal, and local agencies to detect and monitor residues that are suspected to be in environmental compartments due to outdoor uses and accidental releases of registered chemicals. Thre e soil and water analy tical methods were initially submitted, by

the registrant as ILVs**44**



### documenting methods developed b y Covance laboratory for soil (MRID 48341916) and RRC laboratory for drinking (tap) water and surface (river) water (MRIDs 483419 - 17 and 483419 - 18, respectivel y) . These three methods were developed by the two laboratories, stated above, using German standard multi - residue methods. Therefore, These ILVs are considered, b y the Agency, to be ECMs and were re - submitted as such under new MRID numbers (MRIDs 488421 - 02/01/03 representing ECMs submittals for soil/drinking water/surface water, respectively). Therefore, the registrant is requested to submit ILVs for these ECMs which are to be conducted b y independent laboratories other than the devel opers of the methods. Submitted ECM for soil was developed b y Covance laboratory based on the German multi residue method S19 7 

### . The method determines TM in soil using GC/MS at the working range of 0.01 and 10.0 mg a.i/Kg (MRID 488421 - 02 supplemented by and MRID 48341916) . Overall recovery averaged 98 ± 12.4% (mean ± RSD, range 82 - 124%, n = 10) of the applied and the limit of dete ction (L OD) and quantitation (LOQ) for TM were established at 0.00295 mg/kg and 0.01 mg/kg, respectivel y. It is noted that the established working range of the method (between 0.01 and 10.0 mg a.i/Kg Or 0.01 to 10 ppm) is appropriate because modeled diet - based EECs that may cause ecological risk in the soil is approximately 60 mg a.i/kg (60 ppm) based on chronic risks to small mammals consuming treated seeds (Needs dilution). However, most of the other expected concentrations were at least one to two orders of magnitude less than the highest soil EEC (60 ppm) that may cause ecological risk from soil. Additionally, the highest bulk sediment EECs is in the range of 0.0168 to 0.0169 ppm while lies within the working range of the method. Submitted ECMs for drinking/surface waters were developed b y RRC laboratory based on the German Multi - residue method F12 8 

### . The methods determine TM in drinking (tap) water (MRID 488421 - 01 supplemented by MRID 483419 - 17) and surface (river) water (MRID 488421 - 03 supplemented by MRID 483419 - 18) at levels of 0.1 to 1.0 μg/L . Data on overall recoveries, LODs and LOQs were:

 For drinking (tap) water, overall recovery averaged 90.8 ± 5.8% (mean ± RSD, range 81.8 - 100.1%, n = 10) of the applied.

 For rural surface (river) water, overall recovery averaged 94.4 ± 10.3% (mean ± RSD, range 82.1 - 107.4%, n = 10) of the applied.

 The limit of detection (LOD) for tolclofos - methyl was estimated, for both waters, at ca . 7 **The Ger ma**  **n multi -**  **residue method S19 (** EU guidance document SANCO/825/000): German Research Foundation (Deutsche Forschungsgemeinschaft, or DFG) method S19. DFG - Methode S19, § 35 LMBG (Lebensmittel Bundesgesetz) 00.00 - 34. Method S19 was published as “Modular Multimethod for Detecting Pesticide Residues in Foods” in 1999. 8 **German Multi -**  **residue method F12** (EU guidance document SANCO/825/000): German Standard Methods (Deutsche Einhe itsverfahren), and referenced in "Hanel R., Siebers J. and Alder L.: "Anforderungen an Analysenmethoden zur Bestimmung von Pflanzenschutzmittelruckstandenim Rahmen des Zulassungsverfahrens", Nachrichtenbl. Deut. Pflanzenschutzd., 52, 2000, p. 292"**45**



### 0.01μg/mL , based on lowest calibration standard. A limit of quantitation (L OQ) of 0.1μg/L was established. It is noted that the established working range of the method (between 0.1 to 1.0 μg/L Or 100 to 1,000 ppb) is appropriate for parent TM because modeled surface water EECs range from 0.002 to 0.344 ppb; and all concentration s were at least two order of magnitude less than the highest aquatic EECs that may

cause ecological risk from surface water (3.9 ppb based on chronic effects to saltwater invertebrates). Finally , i t is important to state that while these ECMs and associ ated ILVs are necessary for future use in detect ing and monitoring residues that are suspected to be in environmental compartments due to outdoor uses and accidental releases.

**2. Aquatic Exposure Assessment**  Ba sed on laboratory

fate data, TM is expected to be slightly affected by

hydroly sis (t 1⁄2 

### = 62 day s) and biotic degradation in the soil sy stem ( 90 th 

### % t 1⁄2 

### in day s for 10 soils= 40 day s). However, degradation if TM in most sy stems containing soil or sediment produces relatively high amounts of bound residues. These bound residues were relatively persistent and were quantified b y radioactivity

as percent of a

pplied parent but the nature of these bound residues was not identified. Due to concern about these bound residues, it was decided to include them in the residues of concern; meaning that the stressor is considered to be TM with the unidentified bound resi dues. Therefore, when considering these total residues of concern, the degradation half - lives become much longer than parent alone ( 90 th 

### percentile t 1⁄2 

### for 10 soils= 171 day s ). The aquatic exposure assessment also made use of the measured vapor pressure for TM ( 1.38x 10 - 5 

### torr) and the calculated Henry ’s law constant ( 3.68 x 10 - 6 

### atm m 3 

### mole - 1 

### ) . The label for TM contains a restriction on the maximum seeding rate for all crop groups to 200 lbs treated seeds/A except root vegetable and cotton, which have lim its of 40 and 50 lbs treated seeds/A, respectivel y. A further proposed label restriction limits applications to 0.02 lbs a.i/A/cropping cycle for all uses. Therefore, modeling for the total toxic residue (TTR= parent+ bound residues) was conducted for two different cases, namel y: (1) **A conservative case (Case 1) :**  which is the most conservative for **all crops** : in this case the application rate was assumed to equal 0.02 lbs a.i/A for all crop groups using scenarios that represent each of these groups with the minimum reported seeding depths; and (2) **A realistic (**

**Case 2 )**  **:** which is still conservative for **each representative crop** from each crop group: in this case the application rate was calculated for each of the representative crops from the label application rate specified for its crop group and the seeding rate reported for that crop b y BEAD Memo dated March 24, 2011. For example, in **Case 1** (the conservative case) , the application rate for crop group 15 (cereal grains) was considered to equal 0.02 lbs a.i/A (whi ch is the restricted maximum rate= 200 lbs**46**



### seeds “the maximum seeding rate allowed for this group” x 0.0098 lbs a.i/100 lbs of seed divided by 100 multiplied by

200 = 0.0196 lbs a.i/A) 9 

### . Sixteen scenarios were chosen to represent this group: CAcornOP, FLswe etcornOP, ILCornSTD, KSsorghumSTD, MScornSTD, NCcorn OP, NDcornOP, NDwheatSTD, OHCornSTD, ORswcornOP, ORwheatOP, PA corn STD, STXcornNMC, TX corn OP, TXsorghumOP 10 

### and TXwheatOP. All of these scenarios were run at the same maximum rate of 0.02 lbs a.i/A. Ex ecution of modeling for this conservative **Case 1** was necessary

in order to cover exposure for crops , within each crop group , to which seeding rates were not reported by BEAD In contrast, for **Case 2** (the realistic case) more than one crop was modeled “to represent the same crop group 15” with the expected a.i rate/A calculated from BEAD seeding rate. The crops chosen included:

 **Wheat** modeled at a rate equal to 0.01525 lbs a.i/A (calculated as follows: 156 lbs seed x 0.0098 lbs a.i/100 lbs of seed divided b y 100) using NDwheatSTD, ORwheatOP, and TXwheatOP;  **Barley** modeled at a rate equal to 0.00938 lbs a.i/A (calculated for its reported seeding rate of 96 lbs/A as shown for wheat above) using the same scenarios stated above for wheat;  **Oat/rye** modeled at a rate equal to 0.0088 lbs a.i/A calculated for its reported seeding rate of 90 lbs/A using the same scenarios stated above for wheat;  **Corn** modeled at a rate equal to 0.00324 lbs a.i/A calculated for its reported seeding rate of 33.2 lbs/A using CAcornOP, FL sweetcornOP, ILCornSTD, MScornSTD, NCcorn OP, NDcornOP, OHCornSTD, ORswcornOP, PAcornSTD, STXcornNMC, and TX corn OP;  **Millet** modeled at a rate equal to 0.00147 lbs a.i/A calculated for its reported seeding rate of 15 lbs/A using the corn scenarios stated above for corn; and  **Sorghum** modeled at a rate equal to 0.00089 lbs a.i/A calculated for its reported seeding rate of 9.1 lbs /A using KSsorghumSTD and TXsorghumOP. Finally , ornamental flowers or flowering ornamental include:

 Flowering annuals “planted/flower each season” such as petunia, zinnia**,** marigold and other flowering plants that are grown from bulbs;

 Flowering biennial s “vegetative 1 st 

### season and flowers the 2 nd 

### season”; and

 Flowering perennials

9 Label rate= 0.0098 lb a.i/100 lbs of seeds; therefore the rate= (0.0098/100) lb a.i/1 lb of seeds and the rate per acre when a 200 lbs of seeds is used= 200 x 0.0098/100= 0.0196 lb a.i/A (the rate was stated in the label to be 0.02 lb a.i/A) 10 Note: Scenario Names consists of location, crop and purpose. Location= State name (e.g., STX= south Texas and TX= Texas); Crop= crop name (e.g., corn= corn); Purpose= either standard scenario= STD or scenarios used for special purpose “e.g., OP= for organophosphate cumulati ve assessment, NMC= for N - me thyl carbamate assessment”**47**



### N o seeding rate data are available for these plants, therefore onl y the label maxima rate of 0.02 lbs/A were used in modeling. **a. Modeling inputs**  TM has only

one formulated product label. The end - use product is formulated as flowable and is used directl y to treat “true seeds = no seed parts or vegetative parts” for many crops. Therefore, the source of environmental exposure to TM is from planted seeds and will be directly related to crop scenario and amount of chemical applied (use rates/100 lbs of seed, crop seeding rates and seeding depths). Modeling inputs for **case 1** are summarized in **Table 12**  along with representative scenarios noting that the application dates were set to be the scenario planting dates. **Table 12**  **. Modeling inputs for Case 1**  **and ornamentals**  **(application rate used for all run= 0.02 lbs a.i/A)** * **Crop Group Representative Crop (s)**  **Scenario Minimum Seeding Depth**  **(cm )** 

CG - 1A Carrot FLcarrotSTD **0.32**

Parsley ORmintSTD **0.64**
Turnip FLpotatoeNMC **1.27** WApotatoeNMC **1.27** ME_potatoe **1.27** ID_potato **1.27** Sugarbeet (field, Garden, Seed) CAsugarbeetOP **1.27** MNsugarbeetSTD **1.27** CG - 3 - 07 onion, pearl GAOnion_WirrigSTD **0.64** CAonion_WirrigSTD **0.64** WAonionNMC **0.64** CG - 4 Lettuce & Corn Salad CAlettuceSTD **0.64** CG - 5 Canola (rape) NDcanolaSTD **0.64**

CG - 6 Soy

bean (field/edamame) MSsoybeanSTD **1.91**

Lupine TXalfalfa OP **2.54** ILalfalfa NMC **2.54** NCalfalfa OP **2.54** PAalfalfa OP **2.54** CAalfalfa OP **2.54** MNalfalfa OP **2.54**
Beans (snab, Garden, southern & peas) MIbeansSTD **2.54** ORsnbeansSTD **2.54** WAbeansNMC **2.54** ILbeansNMC **2.54** CG - 8 - 10 peppers FLpeppersSTD **0.64**

Tomato FLtomatoSTD **0.64 48** 

**Crop Group Representative Crop (s)**  **Scenario Minimum Seeding Depth**  **(cm )**  PAtomatoSTD **0.64** CAtomato_WirrigSTD **0.64** CG - 9 Melons (water, honeydew, musk & cantaloupe) TXmelonNMC **1.27**

Cucumber FL cucumber **1.27**

CG - 15 wheat (durum/hard red/white), Barley TXwheatOP **2.54** ORwheatOP **2.54** NDwheatSTD **2.54**

corn (field/pop/sweet) & millet for seed FLScorn OP **3.81** TX corn OP **3.81** OHCornSTD **3.81** CAcornOP **3.81** NCcornOP **3.81** ORscornOP **3.81** MScornSTD **3.81** NDcornOP **3.81** OHCornSTD **3.81** NCcornESTD **3.81** ILCornSTD **3.81** PAcornSTD **3.81** CG - 17 Sorghum for forage TXsorghumOP **1.91** KSsorghumSTD **1.91** Grass, Sudan grass & annual/perennial ryegrass ORgrassseedSTD **0.64**

CG - 18 Lespedeza & sericea for forage CAlettuceSTD **0.64**

Lupine for forage TXalfalfa OP **2.54** ILalfalfa NMC **2.54** NCalfalfa OP **2.54** PAalfalfa OP **2.54** CAalfalfa OP **2.54** MNalfalfa OP **2.54** CG - 19 cilantro ORmintSTD **0.64** CG - 20 mustard greens FLcabbageSTD **0.64**

Cotton cotton TX cotton OP **1.27** TX cotton NMC **1.27** MScottonSTD **1.27** NCcottonSTD **1.27** CAcotton_WirrigSTD **1.27** Conifer Conifer ORXmasTreeSTD **2.54** Ornamental Flowering annuals, biennials, and perennials TN, FL, NJ, OR & MI nurserySTD_V2.txt **0.64 49** 

**Crop Group Representative Crop (s)**  **Scenario Minimum Seeding Depth**  **(cm )**  All Vegetables Vegetables TX vegetables NMC **0.64** PA vegetables NMC **0.64** 

### * Note that this application rate is based on two label statements: (1) Do not appl y more than a total of 0.02 lbs of Tolclofos - methyl active ingredient per acre per cropping cycle; and (2) A restricted maximum seeding rate allowed of 40 lbs seeds/A for CG - 1A, 50 lbs seeds/A for Cotton and 200 lbs seeds/A for **all** others Modeling inputs for **Case 2** are summarized in **Table 13**  along with representative scenarios noting that the application dates were set to be the scenario planting dates. In this case, representative scenarios are run using realistic appl ication rates (based on the BEAD memo) calculated for crops being modeled. **Table 13**  **. Modeling inputs for**  **Case 2 Crop**  **Group Representative Crop (s)**  **1 Scenario**  **Lbs Seeds/A**  **Lb a.i/A Minimum**  **Seeding Depth (cm**  **)** Burdock FLcarrotSTD 1.6 0.00078 **0.32** Carrot FLcarrotSTD 12 0.00584 **0.32** Parsley ORmintSTD 40 0.01955 **0.64** radish GAOnion_WirrigSTD 32.7 0.01596 **0.64** CAonion_WirrigSTD 32.7 0.01596 **0.64** WAonion NMC 32.7 0.01596 **0.64** rutabaga ME_potatoe 2 0.00098 **1.27** ID_potato 2 0.00098 **1.27** Sugarbeet (field, Garden, Seed) MNsugarbeetSTD 25 0.01222 **1.27** CAsugarbeet_WirrigOP 25 0.01222 **1.27** CAsugerbeetOP 25 0.01222 **1.27** Turnip ME_potatoe 6 0.00293 **1.27** ID_potato 6 0.00293 **1.27**

CG - 3 - 07 onion, pearl GAOnion_WirrigSTD 110 0.01075 **0.64** CAonion_WirrigSTD 110 0.01075 **0.64** WAOnion NMC 110 0.01075 **0.64** Onion (dry

/green/seed) GAOnion_WirrigSTD 13 0.00127 **0.64** CAonion_WirrigSTD 13 0.00127 **0.64** WAonion NMC 13 0.00127 **0.64**

CG - 4 Coriander, leaf ORmintSTD 50 0.00489 **0.64**

Corn Salad CAlettuceSTD 37 0.00362 **0.64** Lettuce (head/leaf) Celery CAlettuceSTD 0.8 0.00008 **0.64** Spinach CAlettuceSTD 25 0.01222 **1.27 50** 

**Crop Group**  **Representative Crop (s) 1**  **Scenario Lbs**  **Seeds/A Lb a.i/A**  **Minimum Seeding Depth**  **(cm )** 

CG - 5 Broccoli, Collard FLcabbageSTD 5 0.00049 **0.64**

Brussels sprouts FLcabbageSTD 0.4 0.00004 **0.64** Cabbage Chinese (bok- choy) FLcabbageSTD 2.2 0.00021 **0.64** Cauliflower FLcabbageSTD 0.3 0.00003 **0.64** Kale FLcabbageSTD 5.8 0.00056 **0.64**

CG - 6 Beans (snab) & Garden southern peas ILbeansNMC 200 0.04257 **2.54** MIbeansSTD 200 0.04257 **2.54** ORsnbeansSTD 200 0.04257 **2.54** WAbeansNMC 200 0.04257 **2.54**
Beans (dry & Lima) ILbeansNMC 163.4 0.01596 **2.54** MIbeansSTD 163.4 0.01596 **2.54** ORsnbeansSTD 163.4 0.01596 **2.54** WAbeansNMC 163.4 0.01596 **2.54**

Lupine TXalfalfaOP 160 0.01564 **2.54** ILalfalfaNMC 160 0.01564 **2.54** NCalfalfaOP 160 0.01564 **2.54** PAalfalfaOP 160 0.01564 **2.54** CAalfalfa_WirrigOP 160 0.01564 **2.54** MNalfalfaOP 160 0.01564 **2.54** Soy bean (field/edamame ) MSsoybeanSTD 166.7 0.01629 **1.91**

CG - 8 - 10 Peppers FLpeppersSTD 4.2 0.00041 **0.64**

Tomato STXvegetableNMC 1.1 0.00011 **0.64** FLtomatoSTD 1.1 0.00011 **0.64** PAvegetableNMC 1.1 0.00011 **0.64** PAtomatoSTD 1.1 0.00011 **0.64** CAtomato_WirrigSTD 1.1 0.00011 **0.64**

CG - 9 Cucumber FLcucumberSTD 11.6 0.00114 **1.27** STXmelonNMC 11.6 0.00114 **1.27** Melons (water, honeydew, musk, cantaloupe ) FLcucumberSTD 9.1 0.00089 **1.27** STXmelonNMC 9.1 0.00089 **1.27** Squash, summer & winter bush type FLcucumberSTD 8 0.00078 **1.27** STXmelonNMC 8 0.00078 **1.27** Pum pkin, vine type, small FLcucumberSTD 4.5 0.00044 **1.27** STXmelonNMC 4.5 0.00044 **1.27**

CG - 15 Barley, Buckwheat TXwheatOP 96 0.00938 **2.54** NDwheatSTD 96 0.00938 **2.54** ORwheatOP 96 0.0088 **2.54** Corn (field/pop/sweet) MScornSTD 33.2 0.00324 **3.81 51** 

**Crop Group**  **Representative Crop (s) 1**  **Scenario Lbs**  **Seeds/A Lb a.i/A**  **Minimum Seeding Depth**  **(cm )**  FLsweetcornOP 33.2 0.00324 **3.81** TXcornOP 33.2 0.00324 **3.81** STXcornNMC 33.2 0.00324 **3.81** CAcornOP 33.2 0.00324 **3.81** NCcornESTD 33.2 0.00324 **3.81** OHCornSTD 33.2 0.00324 **3.81** ILCornSTD 33.2 0.00324 **3.81** NCcornOP 33.2 0.00324 **3.81** PAcornSTD 33.2 0.00324 **3.81** ORswcornOP 33.2 0.00324 **3.81** NDcornOP 33.2 0.00324 **3.81**

Millet, pearl FLsweetcornOP 15 0.00147 **3.81** MScornSTD 15 0.00147 **3.81** TXcornOP 15 0.00147 **3.81** STXcornNMC 15 0.00147 **3.81** CAcornOP 15 0.00147 **3.81** NCcornESTD 15 0.00147 **3.81** OHCornSTD 15 0.00147 **3.81** ILCornSTD 15 0.00147 **3.81** NCcorn OP 15 0.00147 **3.81** PAcornSTD 15 0.00147 **3.81** ORswcornOP 15 0.00147 **3.81** NDcornOP 15 0.00147 **3.81** Oats & rye TXwheatOP 90 0.0088 **2.54** NDwheatSTD 90 0.0088 **2.54** ORwheatOP 90 0.0088 **2.54** Sorghum for grain TXsorghumOP 9.1 0.00089 **1.91** KSsorghumSTD 9.1 0.00089 **1.91** Wheat (durum/hard red/white), Barley & Triticale TXwheatOP 156 0.01525 **2.54** NDwheatSTD 156 0.01525 **2.54** ORwheatOP 156 0.01525 **2.54**

CG - 17 Oats, triticale & rye for forage NDwheatSTD 109 0.01065 **2.54**

Grass, Sudan grass , annual ryegrass & perennial ryegrass ORgrassseedSTD 25 0.00244 **0.64** Grass, Indian ORgrassseedSTD 12 0.00117 **0.64** Grass, Kentucky & orchard grass & reed canary grass ORgrassseedSTD 10 0.00098 **0.64** Grass, eastern gama & switch grass ORgrassseedSTD 9 0.00088 **0.64** Grass, Bermuda ORgrassseedSTD 8 0.00078 **0.64** Millet for forage FLsweetcornOP 30 0.00293 **3.81 52** 

**Crop Group**  **Representative Crop (s) 1**  **Scenario Lbs**  **Seeds/A Lb a.i/A**  **Minimum Seeding Depth**  **(cm )**  MScornSTD 30 0.00293 **3.81** TXcornOP 30 0.00293 **3.81** STXcornNMC 30 0.00293 **3.81** CAcornOP 30 0.00293 **3.81** NCcornESTD 30 0.00293 **3.81** OHCornSTD 30 0.00293 **3.81** ILCornSTD 30 0.00293 **3.81** NCcorn OP 30 0.00293 **3.81** PAcornSTD 30 0.00293 **3.81** ORswcornOP 30 0.00293 **3.81** NDcornOP 30 0.00293 **3.81** Oats, triticale & rye for forage TXwheatOP 109 0.01065 **2.54** ORwheatOP 109 0.01065 **2.54** Sorghum for forage TXsorghumOP 12 0.00117 **1.91** KSsorghumSTD 12 0.00117 **1.91**

CG - 18 Alfalfa TXalfalfaOP 15 0.00147 **0.64** ILalfalfaNMC 15 0.00147 **0.64** NCalfalfaOP 15 0.00147 **0.64** CAalfalfa_WirrigOP 15 0.00147 **0.64** MNalfalfaOP 15 0.00147 **0.64** Collards & Forage, kale for forage FLcabbageSTD 4 0.00039 **0.64**

Lespedeza TXalfalfaOP 35 0.00342 **0.64** NCalfalfaOP 35 0.00342 **0.64** ILalfalfaNMC 35 0.00342 **0.64** PAalfalfaOP 35 0.00362 **0.64** CAalfalfa_WirrigOP 35 0.00342 **0.64** MNalfalfaOP 35 0.00342 **0.64**

Lupine for forage TXalfalfaOP 160 0.01564 **2.54** ILalfalfaNMC 160 0.01564 **2.54** NCalfalfaOP 160 0.01564 **2.54** PAalfalfaOP 160 0.01564 **2.54** CAalfalfa_WirrigOP 160 0.01564 **2.54** MNalfalfaOP 160 0.01564 **2.54**

Vetch TXalfalfaOP 9 0.00088 **0.64** ILalfalfaNMC 9 0.00088 **0.64** PAalfalfaOP 9 0.00147 **0.64** NCalfalfaOP 9 0.00088 **0.64** CAalfalfa_WirrigOP 9 0.00088 **0.64 53** 

**Crop Group**  **Representative Crop (s) 1**  **Scenario Lbs**  **Seeds/A Lb a.i/A**  **Minimum Seeding Depth**  **(cm )**  MNalfalfaOP 9 0.00088 **0.64**

CG - 19 Borage ORmintSTD 15 0.00147 **0.64**

Burnet ORmintSTD 3.4 0.00033 **0.64** Cilantro ORmintSTD 50 0.00489 **0.64** Dill weed ORmintSTD 8 0.00078 **0.64**

CG - 20 Canola (rape) NDcanolaSTD 8.2 0.0008 **0.64**

Mustard greens FLcabbageSTD 7 0.00068 **0.64** Safflower TXwheatOP 35 0.00342 **2.54** ORwheatOP 35 0.00342 **2.54** NDwheatSTD 35 0.00342 **2.54**

Sesame TXcottonOP 12 0.00117 **0.64** MSsoybeanSTD 12 0.00117 **0.64** STXcottonNMC 12 0.00117 **0.64** MScottonSTD 12 0.00117 **0.64** NCcottonSTD 12 0.00117 **0.64** CAcotton_WirrigSTD 12 0.00117 **0.64**

Sunflower MScornSTD 4 0.00039 **2.54** FLsweetcornOP 4 0.00039 **2.54** TXcornOP 4 0.00039 **2.54** STXcornNMC 4 0.00039 **2.54** CAcornOP 4 0.00039 **2.54** NCcornESTD 4 0.00039 **2.54** OHCornSTD 4 0.00039 **2.54** ILCornSTD 4 0.00039 **2.54** NCcornOP 4 0.00039 **2.54** PAcornSTD 4 0.00039 **2.54** ORswcornOP 4 0.00039 **2.54** NDcornOP 4 0.00039 **2.54** Conifer Conifer ORXmasTreeSTD 5 0.00049 **2.54**

Cotton Cotton TXcottonOP 18.9 0.00923 **1.27** STXcottonNMC 18.9 0.00923 **1.27** MScottonSTD 18.9 0.00923 **1.27** NCcottonSTD 18.9 0.00923 **1.27** CAcotton_WirrigSTD 18.9 0.00923 **1.27 1**  Based on the highest seeding rate for listed crops in this column. 

### Environmental fate and transport based on total residues of concern (parent plus bound residues) and other data used as parameters for PRZM/EXAMS runs are listed in **Table 14**  .**54**

**Table 14**  **. Summary of PRZM/EXAMS environmental fate and transport data used as aquatic exposure inputs (TTR=total toxic residues).**  **Input Parameter (Unit) Value**  **Reference** Molecular Weight g/mole 301.12 Registrant data Vapor pressure **1.38 x 10 -**  **5 torr**  @ 24.8 °C 417018 - 01 Henry’s la w constant **3.68 x 10 -**  **6** atm m 3 mole - 1 Calculated from value at 20 °C (483419 - 01)** Solubility in Water (mg/L) 1.1 FAO **1** & 483419 - 14 and Photolysis in Water (t1⁄2 in days @ pH 7) **Considered Stable** 414229 - 02 Aerobic Soil Metabolism (90 th % t1⁄2 in days for 10 soils) **171** 427032 - 01; 001561 - 06; 483419 - 23 supplemented by 483419 - 25; and 483419 - 24 Hydroly sis (t1⁄2 in days @ pH 7) **61 days** 417147 - 01 Aerobic Aquatic Metabolism **Considered Stable**  Hydroly sis is significant Anaerobic Aquatic Metabolism **Considered Stable** Hydroly sis is significant Koc (Average of five values in L/Kg) **3,279** Average value Application rate and frequency Once/season at time of planting Application intervals Chemical Application Method (CAM) **5** (depth varies with crop) Application Efficiency

/ Spray Drift Fraction **100% /0%**  (seed treatment) 

### b. **Aquatic EECs** Aquatic exposure surface water EECs for the various crop use patterns are summarized in **Table 15**  for **Case 1** and in **Table 16**  for **Case 2.** Example output from the PRZM/EXAMS modeling is provided in **Appendix H. Table**  **15 . Surface water 1**  **- in**  **- 10 Year EECs (μg/L) for TM**  **1 use patterns**  **( Case 1**  **) Crop Group**  **Scenario Peak (ppb)**  **21 -** **day (ppb) 60** **- day (ppb)** 

CG - 1A FLcarrotSTD 0.344 0.194 0.116

ORmintSTD 0.028 0.016 0.012 FLpotatoNMC 0.090 0.054 0.040 WApotatoNMC 0.025 0.013 0.008 ME_potato 0.036 0.024 0.018 ID_potato 0.020 0.018 0.016 CAsugarbeetOP 0.018 0.010 0.007 MNsugarbeetSTD 0.028 0.016 0.011 CG - 3 - 07 GAOnion_WirrigSTD 0.185 0.116 0.075

CAonion_WirrigSTD 0.027 0.016 0.011 WAonionNMC 0.008 0.004 0.002 CG - 4 CAlettuceSTD 0.171 0.098 0.062**55**

**Crop Group Scenario**  **Peak (ppb) 21**  **- day (ppb)**  **60 -** **day (ppb)**

ORmintSTD 0.028 0.016 0.012 CG - 5 NDcanolaSTD 0.053 0.031 0.020

CG - 6 MSsoybeanSTD 0.131 0.070 0.057

TXalfalfa OP 0.064 0.037 0.026 ILalfalfa NMC 0.038 0.022 0.016 NCalfalfa OP 0.033 0.021 0.014 PAalfalfa OP 0.029 0.018 0.012 CAalfalfa OP 0.015 0.009 0.007 MNalfalfa OP 0.010 0.005 0.003 MIbeansSTD 0.023 0.015 0.010 ORsnbeansSTD 0.022 0.014 0.011 WAbeansNMC 0.018 0.010 0.005 ILbeansNMC 0.042 0.028 0.021

CG - 8 - 10 FLpeppersSTD 0.340 0.209 0.147

FLtomatoSTD 0.208 0.114 0.087 PAtomatoSTD 0.105 0.060 0.042 CAtomato_WirrigSTD 0.047 0.029 0.019 CG - 9 TXmelonNMC 0.154 0.084 0.057

FL cucumber 0.275 0.161 0.092

CG - 15 TXwheatOP 0.082 0.056 0.034

ORwheatOP 0.010 0.006 0.005 NDwheatSTD 0.013 0.007 0.005 FLScorn OP 0.050 0.030 0.017 TX corn OP 0.045 0.025 0.017 OHCornSTD 0.017 0.010 0.006 CAcornOP 0.023 0.014 0.009 NCcornOP 0.012 0.008 0.005 ORscornOP 0.008 0.005 0.004 MScornSTD 0.050 0.032 0.022 NDcornOP 0.005 0.003 0.002 NCcornESTD 0.018 0.012 0.008 ILCornSTD 0.013 0.008 0.005 PAcornSTD 0.010 0.006 0.004 CG - 17 TXsorghumOP 0.196 0.101 0.061

KSsorghumSTD 0.070 0.043 0.030 ORgrassseedSTD 0.042 0.024 0.017 CG - 18 CAlettuceSTD 0.171 0.098 0.062

TXalfalfa OP 0.064 0.037 0.026 ILalfalfa NMC 0.038 0.022 0.016**56**

**Crop Group Scenario**  **Peak (ppb) 21**  **- day (ppb)**  **60 -** **day (ppb)**

NCalfalfa OP 0.033 0.021 0.014 PAalfalfa OP 0.029 0.018 0.012 CAalfalfa OP 0.015 0.009 0.007 MNalfalfa OP 0.010 0.005 0.003 CG - 19 ORmintSTD 0.028 0.016 0.012 CG - 20 FLcabbageSTD 0.123 0.073 0.043

Cotton TX cotton OP 0.211 0.119 0.079

TX cotton NMC 0.193 0.104 0.068 MScottonSTD 0.143 0.089 0.073 NCcottonSTD 0.091 0.059 0.042 CAcotton_WirrigSTD 0.027 0.014 0.012 Conifer ORXmasTreeSTD 0.016 0.009 0.005

Flowering Ornamental TNnurserySTD_V2.txt 0.219 0.128 0.089

FLnurserySTD_V2.txt 0.146 0.088 0.072 NJnurserySTD_V2.txt 0.142 0.080 0.054 ORnurserySTD_V2.txt 0.063 0.039 0.025 MInurserySTD_V2.txt 0.046 0.034 0.026 All Vegetables TX vegetables NMC 0.284 0.149 0.096

PA vegetables NMC 0.166 0.110 0.070 1 EECs reflect TM + bound residues **Table 16**  **. Surface water 1 -**  **in -**  **10 Year EECs (μg/L) for TM 1**  **use patterns ( Case 2** **) Crop**  **Group Representative Crop(s)**  **2 Scenario**  **Peak (ppb)**  **21 -** **day**

**(ppb) 60** **- day (ppb)** 

CG - 1A Burdock FLcarrotSTD 0.014 0.008 0.005

Carrot FLcarrotSTD 0.100 0.056 0.034 Parsley ORmintSTD 0.027 0.016 0.012 radish GAOnion_WirrigSTD 0.148 0.093 0.060 CAonion_WirrigSTD 0.022 0.013 0.009 WAonion NMC 0.006 0.003 0.002 rutabaga ME_potatoe 0.002 0.001 0.001 ID_potato 0.001 0.001 0.001 Sugarbeet (field, Garden, Seed) MNsugarbeetSTD 0.017 0.010 0.007 CAsugarbeet_WirrigOP 0.011 0.006 0.004 CAsugerbeetOP 0.011 0.006 0.004 Turnip ME_potatoe 0.005 0.003 0.003 ID_potato 0.003 0.003 0.002 CG - 3 - 07 onion, pearl GAOnion_WirrigSTD 0.099 0.062 0.040 CAonion_WirrigSTD 0.015 0.009 0.006**57**

**Crop Group**  **Representative Crop(s) 2**  **Scenario Peak**  **(ppb) 21**  **- day** 

**(ppb) 60** **- day (ppb)**  WAOnion NMC 0.004 0.002 0.001 Onion (dry/green/seed) GAOnion_WirrigSTD 0.012 0.007 0.005 CAonion_WirrigSTD 0.002 0.001 0.001 WAonion NMC 0.000 0.000 0.000

CG - 4 Coriander, leaf ORmintSTD 0.007 0.004 0.003

Corn Salad CAlettuceSTD 0.046 0.026 0.016 Lettuce (head/leaf); and Celery CAlettuceSTD 0.001 0.001 0.000 Spinach CAlettuceSTD 0.105 0.060 0.038

CG - 5 Broccoli, Collard FLcabbageSTD 0.003 0.002 0.001

Brussels sprouts FLcabbageSTD 0.000 0.000 0.000 Cabbage Chinese (bok- choy) FLcabbageSTD 0.001 0.001 0.000 Cauliflower FLcabbageSTD 0.000 0.000 0.000 Kale FLcabbageSTD 0.003 0.002 0.001

CG - 6 Beans (snab) & Garden; southern peas ILbeansNMC 0.042 0.028 0.021 MIbeansSTD 0.023 0.015 0.010 ORsnbeansSTD 0.022 0.014 0.011 WAbeansNMC 0.018 0.010 0.005
Beans (dry & Lima) ILbeansNMC 0.034 0.023 0.017 MIbeansSTD 0.018 0.012 0.008 ORsnbeansSTD 0.017 0.011 0.009 WAbeansNMC 0.014 0.008 0.004

Lupine TXalfalfaOP 0.050 0.029 0.020 ILalfalfaNMC 0.029 0.017 0.012 NCalfalfaOP 0.026 0.016 0.011 PAalfalfaOP 0.023 0.014 0.010 CAalfalfa_WirrigOP 0.012 0.007 0.005 MNalfalfaOP 0.008 0.004 0.002 Soy bean (field/edamame) MSsoybeanSTD 0.107 0.057 0.047

CG - 8 - 10 Peppers FLpeppersSTD 0.008 0.005 0.003

Tomato STXvegetableNMC 0.001 0.001 0.000 FLtomatoSTD 0.001 0.001 0.000 PAvegetableNMC 0.001 0.000 0.000 PAtomatoSTD 0.000 0.000 0.000 CAtomato_WirrigSTD 0.000 0.000 0.000

CG - 9 Cucumber FLcucumberSTD 0.016 0.009 0.005 STXmelonNMC 0.009 0.005 0.003 Melons (water, honeydew, musk, cantaloupe) FLcucumberSTD 0.012 0.007 0.004 STXmelonNMC 0.007 0.004 0.003 Squash, summer & winter bush type FLcucumberSTD 0.011 0.006 0.004**58**

**Crop Group**  **Representative Crop(s) 2**  **Scenario Peak**  **(ppb) 21**  **- day** 

**(ppb) 60** **- day (ppb)**  STXmelonNMC 0.006 0.003 0.002 Pum pkin, vine type, small FLcucumberSTD 0.006 0.004 0.002 STXmelonNMC 0.003 0.002 0.001

CG - 15 Barley, Buckwheat TXwheatOP 0.039 0.026 0.016 NDwheatSTD 0.006 0.003 0.002 ORwheatOP 0.005 0.003 0.002

Corn (field/pop/sweet) MScornSTD 0.008 0.005 0.003 FLsweetcornOP 0.008 0.005 0.003 TXcornOP 0.007 0.004 0.003 STXcornNMC 0.005 0.003 0.002 CAcornOP 0.004 0.002 0.001 NCcornESTD 0.003 0.002 0.001 OHCornSTD 0.003 0.002 0.001 ILCornSTD 0.002 0.001 0.001 NCcornOP 0.002 0.001 0.001 PAcornSTD 0.002 0.001 0.001 ORswcornOP 0.001 0.001 0.001 NDcornOP 0.001 0.000 0.000

Millet, pearl FLsweetcornOP 0.004 0.002 0.001 MScornSTD 0.004 0.002 0.002 TXcornOP 0.003 0.002 0.001 STXcornNMC 0.002 0.001 0.001 CAcornOP 0.002 0.001 0.001 NCcornESTD 0.001 0.001 0.001 OHCornSTD 0.001 0.001 0.000 ILCornSTD 0.001 0.001 0.000 NCcorn OP 0.001 0.001 0.000 PAcornSTD 0.001 0.000 0.000 ORswcornOP 0.001 0.000 0.000 NDcornOP 0.000 0.000 0.000 Oats & rye TXwheatOP 0.036 0.025 0.015 NDwheatSTD 0.006 0.003 0.002 ORwheatOP 0.004 0.003 0.002 Sorghum for grain TXsorghumOP 0.011 0.006 0.004 KSsorghumSTD 0.003 0.002 0.001 Wheat (durum/hard red/white), Barley & Triticale TXwheatOP 0.063 0.043 0.026 NDwheatSTD 0.010 0.005 0.004 ORwheatOP 0.008 0.005 0.004 CG - 17 Oats, triticale & rye for forage NDwheatSTD 0.007 0.004 0.003**59**

**Crop Group**  **Representative Crop(s) 2**  **Scenario Peak**  **(ppb) 21**  **- day** 

**(ppb) 60** **- day (ppb)**  Grass, Sudan grass, annual ryegrass & perennial ryegrass ORgrassseedSTD 0.005 0.003 0.002 Grass, Indian ORgrassseedSTD 0.002 0.001 0.001 Grass, Kentucky & orchard grass & reed canary grass ORgrassseedSTD 0.002 0.001 0.001 Grass, eastern gama & switch grass ORgrassseedSTD 0.002 0.001 0.001 Grass, Bermuda ORgrassseedSTD 0.002 0.001 0.001

Millet for forage FLsweetcornOP 0.008 0.005 0.003 MScornSTD 0.007 0.005 0.003 TXcornOP 0.007 0.004 0.003 STXcornNMC 0.004 0.003 0.002 CAcornOP 0.004 0.002 0.001 NCcornESTD 0.003 0.002 0.001 OHCornSTD 0.002 0.001 0.001 ILCornSTD 0.002 0.001 0.001 NCcorn OP 0.002 0.001 0.001 PAcornSTD 0.001 0.001 0.001 ORswcornOP 0.001 0.001 0.001 NDcornOP 0.001 0.000 0.000 Oats, triticale & rye for forage TXwheatOP 0.063 0.043 0.026 ORwheatOP 0.008 0.005 0.004 Sorghum for forage TXsorghumOP 0.011 0.006 0.004 KSsorghumSTD 0.004 0.003 0.002

CG - 18 Alfalfa TXalfalfaOP 0.017 0.010 0.007 ILalfalfaNMC 0.010 0.006 0.004 NCalfalfaOP 0.008 0.005 0.003 CAalfalfa_WirrigOP 0.004 0.003 0.002 MNalfalfaOP 0.003 0.001 0.001 Collards & Forage, kale for forage FLcabbageSTD 0.002 0.001 0.001

Lespedeza TXalfalfaOP 0.050 0.029 0.020 NCalfalfaOP 0.026 0.016 0.011 ILalfalfaNMC 0.024 0.014 0.010 PAalfalfaOP 0.023 0.014 0.010 CAalfalfa_WirrigOP 0.012 0.007 0.005 MNalfalfaOP 0.008 0.004 0.002

Lupine for forage TXalfalfaOP 0.050 0.029 0.020 ILalfalfaNMC 0.029 0.017 0.012 NCalfalfaOP 0.026 0.016 0.011 PAalfalfaOP 0.023 0.014 0.010 CAalfalfa_WirrigOP 0.012 0.007 0.005 MNalfalfaOP 0.008 0.004 0.002**60**

**Crop Group**  **Representative Crop(s) 2**  **Scenario Peak**  **(ppb) 21**  **- day** 

**(ppb) 60** **- day (ppb)** 

Vetch TXalfalfaOP 0.010 0.006 0.004 ILalfalfaNMC 0.006 0.004 0.003 PAalfalfaOP 0.005 0.003 0.002 NCalfalfaOP 0.005 0.003 0.002 CAalfalfa_WirrigOP 0.003 0.002 0.001 MNalfalfaOP 0.002 0.001 0.000

CG - 19 Borage ORmintSTD 0.002 0.001 0.001

Burnet ORmintSTD 0.001 0.000 0.000 Cilantro ORmintSTD 0.007 0.004 0.003 Dill weed ORmintSTD 0.001 0.001 0.000

CG - 20 Canola (rape) NDcanolaSTD 0.002 0.001 0.001

Mustard greens FLcabbageSTD 0.004 0.003 0.002 Safflower TXwheatOP 0.014 0.009 0.006 ORwheatOP 0.002 0.001 0.001 NDwheatSTD 0.000 0.000 0.000

Sesame TXcottonOP 0.097 0.055 0.036 MSsoybeanSTD 0.018 0.010 0.008 STXcottonNMC 0.017 0.009 0.006 MScottonSTD 0.013 0.008 0.007 NCcottonSTD 0.010 0.006 0.005 CAcotton_WirrigSTD 0.002 0.001 0.001

Sunflower MScornSTD 0.002 0.001 0.001 FLsweetcornOP 0.002 0.001 0.001 TXcornOP 0.002 0.001 0.001 STXcornNMC 0.001 0.001 0.000 CAcornOP 0.001 0.001 0.000 NCcornESTD 0.001 0.000 0.000 OHCornSTD 0.001 0.000 0.000 ILCornSTD 0.001 0.000 0.000 NCcornOP 0.000 0.000 0.000 PAcornSTD 0.000 0.000 0.000 ORswcornOP 0.000 0.000 0.000 NDcornOP 0.000 0.000 0.000 Conifer Conifer ORXmasTreeSTD 0.000 0.000 0.000

Cotton Cotton TXcottonOP 0.097 0.055 0.036 STXcottonNMC 0.089 0.048 0.031 MScottonSTD 0.065 0.041 0.034 NCcottonSTD 0.042 0.027 0.019 CAcotton_WirrigSTD 0.013 0.007 0.005**61**

1 ECs reflect TM + bound residues ; 2 Based on the highest seeding rate for listed crops in this column. 

### A summary

of all surface water exposure EEC results ( **Case 1** , **Case 2** and O rnamentals ) are included in **Figure 8**  (shows only the range of EECs obtained for scenarios representing the crop or crop group.**62**



### Figure **8 . Surface water exposure EECs (**  **Case 1 ,**  **Case 2 and O**  **rnamentals)** With an average K oc 

### of over 3,000 and a log Kow 

### of 3.8, TM is expected to partition onto sediment particles to a relatively significant extent. Therefore, exposure to pore water in aquatic sy stems was also obtained for selected runs inc luding scenarios with the highest and lowest surface water EECs. In this case, pore - water EECs for the most conservative runs ( **Case 1** runs) are summarized in **Table 17**  

### .

0 0. 05 0. 1 0. 15 0. 2 0. 25 0. 3 0. 35 0. 4**E x** **p o** **s u** **r e** **E E** **C s** **( p** **p b** **)**

0 0. 05 0. 1 0. 15 0. 2 0. 25**E x** **p o** **s u** **r e** **E E** **C s** **( p** **p b** **)**

0 0. 02 0. 04 0. 06 0. 08 0. 1 0. 12 0. 14 0. 16**E x** **p o** **s u** **r e** **E E** **C s** **( p** **p b** **)**

**Crop Gr**  **oup 1**  = Case - 1 ( modled using maximum rate); **2** = Case - 2 ( mo deled using e xpected rate for each crop calculated from seeding rates). Range is mostly taken from modeling results for more tha n one representatative scenarios. 

### 1 

### 2 **1 1**  **1 1**  **1 1** 

**1 1**  **1**

**1 1** 

**1 1**  **1** 

### 2 **2 2**  **2 2**  **2 2**  **2 2**  **2 2**  **2 2** 

**Crop or Crop Group**



### Peak (Acute) **EECs**

**60 -**  **day (Chronic)**  **EECs 21**  **- day**  **(Chronic) EECs** **63**

**Table 17**  **. Pore -** **water 1 -**  **in -**  **10 Year EECs (μg/L) for TM 1**  **use patterns ( Case**  **1 )**  **Crop Group Representative Crop (s)**  **Scenario Peak (ppb)**  **21 -**  **day (ppb)**  **60 -**  **day**

**(ppb) Scenarios with the Highest Surface Water EECs**  All Vegetables Vegetables TX vegetables NMC 0.0630 0.0612 0.0587 PA vegetables NMC 0.0580 0.0578 0.0570 Cotton Cotton TX cotton OP 0.0527 0.0524 0.0512 TX cotton NMC 0.0446 0.0443 0.0428 CG - 17 Sorghum for forage TXsorghumOP 0.0408 0.0406 0.0392 CG - 3 - 07 Onion, pearl GAOnion_WirrigSTD 0.0400 0.0393 0.0372 CG - 9 Melons (water, honeydew,

musk & cantaloupe) TXmelonNMC 0.0367 0.0365 0.0353 CG - 1A Carrot FLcarrotSTD 0.0332 0.0330 0.0316 CG - 6 Soy

bean (field/edamame) MSsoybeanSTD 0.0320 0.0318 0.0306 CG - 4 Lettuce & Corn Salad CAlettuceSTD 0.0240 0.0239 0.0233 **Scenarios with the Lowest Surface Water EECs** CG - 15 Corn (field/pop/sweet) &

millet for seed ILCornSTD 0.0007 0.0007 0.0006 PAcornSTD 0.0005 0.0005 0.0005 CG - 8 - 10 Tomatoes FLtomatoSTD 0.0003 0.0003 0.0003 PAtomatoSTD 0.0002 0.0002 0.0002 CAtomato_WirrigSTD 0.0000 0.0000 0.0000 1 EECs reflect TM + bound residues 

### Furthermore, bulk sediment EECs were also obtained for the highest surface water EEC scenario “FLcarrotSTD”. Modeled EECs were: peak= 16.87μg/kg, 21 - day= 16.75 μg/k g, 60 - day= 16.10μg/kg.
**c. Aquatic Exposure Monitoring (Field Data)**  This is a new pesticide and therefore no data were identified to provide information on aq uatic monitoring. **3. Terrestrial Exposure Assessment** 

**a. Consumption of Treated Seeds**  The T - REX model (v. 1.5, March 2012) is used in this assessment for estimating direct exposure of birds and mammals to TM via consumption of treated seeds. Exposure from the consumption of treated seed is calculated two way s:**64**



### Exposure Method #1 is based on the TM concentration in seed (mg ai/kg seed) for comparing with acute and chronic dose and diet - based toxicity endpoints, and Exposure Method #2 is based on the mg ai/A for estimating LD 50 

### /ft2



### . For exposure method #1, the concentration in treated seed is usuall y determined from the application rate (fl oz of product/100lb seed), % ai, and the density of product. However, the label for TM specifies the maximum allowable application rate in terms of lb ai/100 kg seed (see **Table 3**  ). Across all crop groupings, onl y two different maximum application rates are allowed on the label:

 Cotton & root vegetables (CG1A): **0.048867 lb ai/100 lb seed (= 487.79 mg ai/kg seed)**   All other crops: **0.009773 lb ai/100 lb seed (= 97.73 mg ai/kg seed).** Therefore, these two application rates were used as the basis of subsequent avian and mammalian exposure calculations using exposure method #1 ab ove. Specifically , dose - based EECs (mg/kg - bw) for various size classes of mammals and birds were calculated based on allometric relationships between food intake and body weight to reflect exposure of different weight class of animals. The size classes as sessed are: Birds:  small (20g)

 medium (100g)  large (1000g) Mammals:  small (15g)

 medium (35g)  large (1000g). Equations for the dose - based EEC calculations are described in the T - REX v 1.5 Users Guide. 11 

### Estimated doses (mg ai/kg - bw - d) to the different size classes of birds and mammals are provided in **Table 18**  **. Table**  **18 . Est** **imated Exposure of TM to Birds and Mammals Based on Label Seed Application Rates**  **Animal Size**  **Crop Maximum Seed**  **Application Rate (m**  **g ai/kg seed) Avian Nagy Dose** 

**(m g ai/kg**  **- bw/day)**  **Mam malian Nagy** 

**Dose (m**  **g ai/kg -**  **bw/day)** Small Root Vegetables (CG1A)

& 488 124 103 Medium 70.4 71.4

11 details of this model are available at http://www.epa.gov/oppefed1/models/terrestrial/index.htm#trex**65**

Large Cotton 31.5 16.6 Small All Other Crops* 97.7 24.7 20.7 Medium 14.1 14.3 Large 6.30 3.31 

### *See Table 3 for description of crop groups. Diet - based EECs are also determined assuming 100% of the diet is treated seed (100% available) . Thus, the diet - based EECs are equivalent to the maximum seed application rates shown in **Table 18**  . Terrestrial EECs calculated using exposure method #2 are based on the maximum allowable rate on the label: 0.02 lb ai/A. This value is equivalent to 0.21 mg ai/ft2 

### . It is then compared to the appropriate body- weight adjusted LD 50 

### for determining the fraction of LD 50 

### per square foot. Both exposure method 1 and 2 above involve a number of assumptions including: (1) seeds are readil y available for consumption by wildl ife; (2) 100% of the diet is treated seed ; (3) no degradation of pesticide occurs over time ; and (4) food consumption rates are scalable according to allometric relationships. Uncertainty associated with these and other assumptions is described in **Section IV.C.**  **b. Consumption of Aquatic Biota**  In addition to consumption of treated seeds, the risk to birds and mammals that consume aquatic biota contaminated with TM was also evalutated, since TM is hydrophobic and may bioaccumulate in aquatic food webs. Bioa ccumulation in aquatic biota was estimated using the reported BCF values ( **Table 8**  ) and the KABAM model. Details and result of this evaluation are presented in **Section IV.A.4. c.**  **Terrestrial Exposure Monitoring (Field Data)** TM is a new chemical proposed for registration in the US; therefore, no data are available on terrestrial monitoring.

**4. Non**  **- Target Terrestrial Plant Exposure Assessment**  An exposure assessment for terrestrial plants was not conducted for several reasons . First, the proposed use of TM is for seed treatment. Thus, the usual spray drift exposure anal ys is is not applicable to TM. Second, the label specifies that seeds are to be planted below the soil surface, which would tend to minimize runoff of TM to adj acent areas. Third, while drift of abraded seed coating containing TM residues is a plausible exposure vector to terrestrial plants (and animals), methods to quantify

this exposure route are currently lacking. Lastl y, toxicity data on the effects of TM o n terrestrial plants are not available. The uncertainty associated with not assessing risks to terrestrial plants is further described in **Section IV.C** based on terrestrial plant toxicity data from surrogate chemicals (other OP pesticides).**66**



### C. **Ecological E ffects Characterization**  The effects of TM on aquatic and terrestri al organisms as derived from laboratory studies are summarized in this section. It is important to recognize that the tested species reported herein represent a small fraction of avian, mammalian, aquatic organisms and plant species resident to North America. Specifically , onl y a few surrogate species for both freshwater fish and birds are used to represent all freshwater fish (2000+) and bird (680+) species in the United States. For mammals, acute studies are usuall y limited to Norway rat or the house mo use. Estuarine/marine testing is usually

limited to a crustacean, a mollusk, and a fish. Also, neither reptiles nor amphibians are commonly tested. In the absence of toxicity data for reptiles and terrestrial phase amphibians, this risk assessment uses the sensitivity of birds as a surrogate for terrestrial - phase amphibians and reptiles. Similarly, freshwater fish are used as a surrogate for aquatic - phase amphibians. In general, categories of acute toxicity ranging from “practically nontoxic” to “very highly toxic” have been established for aquatic organisms (based on L C 50 

### and EC 50 

### values or limit of solubility ), mammals (based on acute oral LD 50 

### values), avian species (based on and acute oral LD 50 

### and subacute dietary L C 50 

### values), and non - target inse cts (based on acute contact LD 50 

### values for honey

bees) (U.S. EPA 2001). These categories are presented in **Appendix E** . **1. Aquatic Effects**  The acute and chronic toxicity values associated with freshwater and estuarine/marine species exposure to TM are summarized in **Error! Reference source not found.** 

### Table **19** . Toxicity endpo ints shown in bold represent the most sensitive endpoints within a taxonomic grouping ( e.g ., freshwater fish, freshwater invertebrates, aquatic plants, etc .). These endpoints are termed the “toxicity reference values” which are used for quantitative risk assessment in Section IV . An overview of the toxicity

test results for aquatic organisms is provided in this section with a more detailed summary

of each study

provided in **Appendix D** . An important consideration for interpreting results of aquatic toxic ity studies with TM is its relativel y low solubility

in water (0.7 - 1.0 mg/L). A number of aquatic studies are known or suspected to have problems with the formation of precipitates. In these situations, the actual amount of TM that is dissolved in solut ion is uncertain unless samples are centrifuged and/or filtered prior to anal ys is. Therefore, when available, results are based on centrifuged samples in order to determine the most bioavailable portion of the test material that is comparable to the aquati c EECs. Toxicity

studies of the major degradate, DM - TM are available for freshwater fish, freshwater invertebrates, and aquatic algae. T here are no submitted studies on the formulated product. However, the proposed use pattern of TM (seed treatment) would not invoke concerns associated with exposure to most end use products ( e.g., spray drift).**67**

**Table 19**  **. Toxicity Reference Values For Aquatic Organisms Exposed To Tolclofos Methyl and Metabolite (DM**  **- TM)**  **Exposure Scenario**  **% A.I.**  **Species Dur.**  **Toxicity Reference Value** ** **(95% CL) Effect Notes**  **MRID; Classifi**  **** **cation (Year) Freshwater Fish** 

**Acute** TGAI

97.8% Rainbow Trout

Oncorhynchus mykiss 96 h **LC 50**  **= 0.69** mg a.i./L (0.64 - 0.74) Probit Slope = 16 (8.2 - 24) NOAEC = 0.35 mg ai/L  No mortality or clinical signs of toxicity were observed at or below 0.35 mg ai/L.  At 0.61 and 0.8 mg ai/L, mortality was 30 and 85% respectively and sublethal effects included loss of equilibrium and lethargy.  Results are based on centrifuged samples as precipitate was observed in the two highest treatments (0.61 and 0.8 mg ai/L) 48341930 Acceptable Sousa et al (2003)

TGAI 99.8% Rainbow Trout

Oncorhynchus mykiss 96 h LC 50 = 0.87 mg ai/L (0.31 - 1.3) Probit slope = 4.2 (2.4 - 6.0) NOAEC = 0.05 mg ai/L  No mortality was observed below 0.56 mg ai/L.  Above 0.05 mg ai/L, sublethal effects included abnormal respiration, lethargy, loss of equilibrium, darken color 00156117 Supplemental Miyamoto et al (1982)

DM - TM (98.9%) Rainbow Trout

Oncorhynchus mykiss 96 h LC 50 > 110 mg/L NOAEC = 110 mg/L  No lethal or sublethal effects observed in test concentrations <110 mg/L DM - TM (a metabolite of tolclofos methyl) 47837502 Acceptable Dionne (1998) TGAI 99.8% Carp ( Cyprin us

carpio ) 96 h LC 50 = 2.1 mg ai/L (1.5 - 2.7) Probit slope = 7.7 (3.3 - 12.2) NOAEC = 0.1 mg ai/L  No mortality was observed at or below 1.0 mg ai/L.  Clinical signs of toxicity were observed > 0.18 mg ai/L and included loss of equilibrium, abnormal respiration lethargy, darkened color. 00156118 Supplemental ( Takimoto et al (1981)

TGAI 99.8% Japanese

medaka ( Oryzias latipes) 96 h LC 50 = 3.0 mg ai/L (2.2 - 4.6) Probit slope = 4.2 (2.4 - 5.9) NOAEC = 0.18 mg ai/L  No mortality was observed at or below 0.56 mg ai/L.  Clinical signs of toxicity were observed > 0.32 mg ai/L and included loss of equilibrium, abnormal respiration lethargy, darkened color. 00156118 Supplemental T akimoto et al (1981)

TGAI 99.8% Guppy

( Poecilia reticulata ) 96 h LC 50 = 3.2 mg ai/L (2.4 - 3.9) Probit slope = 5.7 (3.2 - 8.3) NOAEC = 1.0 mg a.i./L  No mortality was observed at 1.0 mg ai/L (lowest treatment).  Occurrence of sublethal effects in specific treatments was not reported. NOAEC based on reported mortality.  90% - 100% mortality > 5.6 mg ai/L. 00156119 Supplemental Takimoto et al (1981)**68**

**Table 19**  **. Toxicity Reference Values For Aquatic Organisms Exposed To Tolclofos Methyl and Metabolite (DM**  **- TM)**  **Exposure Scenario**  **% A.I.**  **Species Dur.**  **Toxicity Reference Value** ** **(95% CL) Effect Notes**  **MRID; Classifi**  **** **cation (Year)** TGAI 97.2% Bluegill

( Lepomis macrochirus ) 96 h LC 50 > 0.72 mg ai/L NOAEC = 0.72 mg ai/L  No lethal or sublethal effects were observed up to and including the highest test concentration (0.72 mg ai/L).  At highest treatment, the bioavailability of TM is uncertain, as a precipitate formed each day and samples apparently wer e not centrifuge prior to analysis 41400301 Supplemental McAllister (1989)

**Chronic** TGAI

97.6% Rainbow Trout

(Oncorhynchus mykiss) 97 d **NOAEC = <0.012 m g**  **a.i./L** LOAEC = 0.012 mg a.i./L  The most sensitive endpoints were fry weight (60d post hatch) and length (37d post hatch) which were significantly reduced relative to negative controls (14% and 4% respectively) at 12 ug ai/L.  Fry survival was significantly reduced at 110 and 200 ug ai/L  Egg hatching was significantly reduced only at the highest concentration (200 ug ai/L) 42106501 Supplemental Cohle and Leak (1991)

**Freshwater Invertebrates**

**Acute** TGAI

98.8% Water flea Daphnia magna 48 h EC 50 48 mg ai/L (42.8 - 53.7) Probit Slope: 10.4 (5.9 - 14.9) NOAEC= 17 mg a.i./L  No mortality at 48 - hr < 26 mg ai/L  90 % immobility at 64 mg ai/L  Precipitates observed at concentrations > 17 mg ai/L;  Although co - solvent was used, there was no indication of filtering or centrifugation prior to analysis. 43528001 Supplemental Murrell et al (1994)

DM - TM (98.9%) Water flea

Daphnia magna 48 h EC 50 > 95 mg/L NOAEC = 95 mg/L  No lethal or sublethal effects observed in test concentrations <95 mg/L DM - TM (a metabolite of tolclofos methyl) 47837501 Acceptable Dionne (1998) TGAI 99.8% Water flea Daphnia pulex 24 h **EC 50**  **= 2.4 mg** **ai/L** (2.1 - 2.8) Probit Slope: 7.3 (4.4 - 10.1) NOAEC= 1.0 mg ai/L  No mortality was reported at any test concentration (1 - 10 mg ai/L nominal)  > 20% immobilization occurred at 1.8 mg ai/L (nominal) and above 00156120 Supplemental Takimoto and Kagoshima (1982) **Chronic** TGAI

97.6% Water flea Daphnia magna 21 d **NOAEC = 0.026 m**  **g ai/L**  LOAEC = 0.062 mg ai/L.  Reproduction and growth of daphnids were significantly reduced at > 0.062 ug ai/L  Daphnid survival was significantly reduced at > 0.19 ug ai/L  No effects were observed on time to first brood at any treatment. 41400303 Supplemental Burgess (1989)

**Estuarine/Marine Fish 69** 

**Table 19**  **. Toxicity Reference Values For Aquatic Organisms Exposed To Tolclofos Methyl and Metabolite (DM**  **- TM)**  **Exposure Scenario**  **% A.I.**  **Species Dur.**  **Toxicity Reference Value** ** **(95% CL) Effect Notes**  **MRID; Classifi**  **** **cation (Year)**

**Acute** TGAI

95.6% Sheepshead

minnow Cyprinodon variegatus 96 h **LC 50**  **>0.372 m g ai/L**  NOAEC=0.372 mg ai/L  No mortality or sublethal effects were reported up to the highest concentration tested ( < 0.372 mg a.i./L based on mean measured)  A precipitate was observed only at the highest test concentration (1000 ug ai/L nominal; 317 ug ai/L measured); samples in this treatment were filtered and centrifuged prior to analysis.  Mean measured concentration at the second highest treatment (372 ug ai/L; non - centrifuged) and the highest treatment (317 ug ai/L; centrifuged) are suggestive of no effects at or near limits of aqueous solubility in seawater. 48341932 Acceptable Palmer et al (2010)

**Chronic** No Data (waiver request accepted)* **Estuarine/Marine Invertebrates**

**Acute** TGAI

95.6% Saltwater mysid Americamysis bahia 96 h LC 50 = 0.327 mg ai/L (0.269 - 0.410) Probit Slope: N/A NOAEC= 0.121 mg ai/L  15%, 65% and 100% mortality occurred at 0.23, 0.46 and 0.74 mg ai/L (mean measured)  Mysids in the control groups and 0.60, and 0.121 mg ai/L showed no sublethal effects. 48341929 Acceptable Palmer et al 2010

TGAI 95.6% Eastern Oyster

( Crassostrea virginica ) 96 h **EC50 = 0.21 m g ai/L**  (0.15 - 0.30 mg ai/L) NOAEC= 0.14 mg ai/L  Shell growth was reduced by 14, 21, 66 and 86% relative to controls at 0.07, 0.14, 0.28 and 0.60 mg ai/L, respectively (mean measured).  Slight precipitate observed at highest treatment; centrifuged samples showed no appreciable difference from uncentrifuged samples 48341928 Acceptable Gallagher et al (2010)**70**

**Table 19**  **. Toxicity Reference Values For Aquatic Organisms Exposed To Tolclofos Methyl and Metabolite (DM**  **- TM)**  **Exposure Scenario**  **% A.I.**  **Species Dur.**  **Toxicity Reference Value** ** **(95% CL) Effect Notes**  **MRID; Classifi**  **** **cation (Year)**

**Chronic** TGAI

95.6% Saltwater mysid Americamysis bahia 38 d **N OAEC**  **50 = 0.0039 m**  **g ai/L**  L OAEC= 0.0082 mg a.i./L  No significant treatment - related effects on F0 mysid survival occurred  Insufficient young were available for effectively evaluating survival of F1 mysids  Mysid reproduction was the most sensitive endpoint; reduced by 50% compared to negative controls (me ans) at 8.2 ug ai/L. This was a biologically determined LOAEC, as test design issues led to poor statistical power. 48341933 Supplemental Palmer et al (20 09 )

**Freshwater Benthic Invertebrates Subchronic**  TGAI

95.6% Freshwater

am phipod, Hyalella azteca 10 d Sediment value: NOAEC (growth and survival) =103 mg a.i./kg dw Pore water value : NOAEC (growth and survival)= 0.854 mg ai/L  Mean percent survival after 10 days was 86, 93, 89, 90, 85, 80, and 95% for the negative control, solvent control, and mean - meas ured 4.8, 12, 24, 48, and 103 mg ai/kg sediment levels, respectively  No sublethal effects on growth (dry weight) were observed at any treatment level vs. negative controls 48341931 Acceptable Thomas et al (2010)

**Chronic** Freshwater midge Chironomus riparius 28 d Sediment value:

**NOAEC (development rate) = 0.186 m**  **g ai/k g**  **dw (=7.7 m**  **g ai/k g**  **- OC)**  Pore water value : **NOAEC (development rate)= 0.013 m**  **g a.i./L**  Test vessels were spiked once via overlying water  Overlying water concentrations decline over time, while pore water and sediment concentrations increased  No effects on percent emergence at any treatment  Development rate were significantly reduced at 0.64 mg/kg dw in sediment (mean measured) 48737504 Supplemental Putt (2002)

**Estuarine/Marine Benthic Invertebrates**  **Subchronic** TGAI

95.6% Saltwater

am phipod Leptocheirus plumulosus 10 d Sediment value: LOAEC=5.3 mg ai/kg dw (survival) **NOAEC= 2.1 m g ai/k** **g dw**  **(survival) (=**  **75 mg** **ai/kg -**  **OC)** Pore water value : LOAEC= 0.42 mg ai/L **NOAEC = 0.38 m g ai/L**   An unbounded LOAEC of 5.3 mg ai/kg dw as obtained from the initial definitive study (61% survival).  An unbounded NOAEC of 2.1 mg ai/kg dw was obtained from a continuation study (95% survival). 48341935 Supplemental Thomas et al (2010)

**Aquatic Plants *****71**

**Table 19**  **. Toxicity Reference Values For Aquatic Organisms Exposed To Tolclofos Methyl and Metabolite (DM**  **- TM)**  **Exposure Scenario**  **% A.I.**  **Species Dur.**  **Toxicity Reference Value** ** **(95% CL) Effect Notes**  **MRID; Classifi**  **** **cation (Year)**

**Algae** TGAI 98.3% Green Algae

Scenedesmus quadricauda 7 -

days EC 50 = >5.6 mg a.i./L LOAEC = 0.1 mg a.i./L NOAEC = 0.032 mg a.i./L (biomass)  LOAEC was determined to be 0.1 mg ai/L based on significant reduction (42%) of biomass (growth inhibition) from control by day 4.  The maximum test level was 5.6 ppm because of the low solubility of the test compound . DMSO used as a co - solvent 0015612 1 Supplemental Takimoto and Ysutaniya (1983)

TGAI 97.83% Green Algae Scenedesmus subspicatus 72 h **EC 50**  **= 0.78 m g a.i./L**  **(** 0.62 - 0.92) **NOAEC = 0.18 m g**  a.i./L (biomass)  Al gae exposed to 0.13, 0.22, 0.39, 0.69 and 1.1 mg a.i./L  Concentrations based on centrifuged samples due to solubility limts at highest test concentration 48737506 Supplemental Sayers (2003)

DM - TM 98.9% Green Algae S. subspicatus 72 h EC 50 >97 mg/L NOAEC = 12 mg/L LOAEC = 23 mg/L  Cell density, biomass and growth rate were reduced by 8.3%, 8.6% and 1.3% at the highest test concentration (97 mg/L) 48737505 Supplemental Hoberg (1998) *W aiver request accepted for chronic toxicity to estuarine/marine fish and aquatic plant toxicity studies (D393184) ** Toxicity endpoints in bold are those used for RQ calculation



### a. **Freshwater Fish** Acute toxicity

studies with technical - grade TM were available for 5 species of freshwater fish: rainbow trout ( Oncorhynchus mykiss ), common carp ( Cyprinus carpio ) , Japanese medaka ( Oryzias latipes ), bluegill sunfish ( Lepomis macrochirus ) and gupp y ( Poecilia reticulata ). All studies were conducted on TGAI with >97% purity ( **Error! Reference source not found.** 

### Table **19** ). Substantial differenc es are noted among these studies in terms of when they were conducted ( e.g ., from the earl y 1980s to 2010), their use of co - solvents (some used dimethylsulfoxide [DMSO] and polyoxyethylene hydrogenated castor oil [HCO]), and their test design (static vs. f low - through; centrifuged vs. uncentrifuged samples). Despite these differences, the LC 50 

### values varied onl y about 5 - fold from 0.69 mg ai/Lto 3.2 mg ai/L across all 5 species. These LC 50 

### values are at or above the reported limit of solubility of TM in la

boratory water (0.7 - 1.0 mg/L; Section 3.B). In two of the tests, precipitates were noted in the higher test concentrations ( e.g ., MRID 48341930 and 41400301). In the former test with rainbow trout, reported concentrations were based on centrifuged sample s. In the latter study with bluegill, samples were not centrifuged prior to anal ysis. Although lack of sample centrifugation in the presence of precipitates can justify

invalidation of a study , it is highl y unlikely that the uncertainty associated with th e bioavailability

of TM in this study

would change the aquatic risk conclusions due to the extremely low aquatic EECs. Therefore, this study is classified as supplemental. All remaining acute toxicity

studies with freshwater fish did not report the presen ce of precipitates (although it is unclear whether investigators looked for precipitates). These remaining studies also used an aty pical co - solvent (DMSO:HCO), although there were no indications that the solvent interfered with integrity of the test and the low aquatic EECs renders uncertainty associated with the use of**72**



### DMSO as not likely

to alter the risk assessment conclusions . Relative to parent TM, the degradate DM - TM was practicall y non - toxic (L C 50 

### >110 mg/L) on an acute exposure basis. For risk ass essment purposes, **an acute toxicity reference value of 0.69 mg ai/L (MRID 48341930) will be used for calculating acute risk quotients for freshwater fish**  . Based on an acute 96 - hr LC 50 

### value of 0.69 mg ai/L, TM is classified as highly toxic to freshwater fish on an acute exposure basis. The observed NOAECs for sublethal effects to freshwater fish included loss of equilibrium, abnormal respiration, lethargy and darkened color and were observed at exposure concentrations ranging between 0.05 to 1.0 mg ai/L. Chronic toxicity

to freshwater fish is estimated based on an earl y life stage study with rainbow trout ( MRID 42106501). Embryos (<24 hours old) were exposed in a flow - through s ys tem to TM (TGAI 97.6%) to mean - measured concentrations of 0.012, 0.02 8, 0.053, 0.11, and 0.20 mg ai/Lfor 97 - day s . A negative control and a solvent control were also tested. Results indicate that hatching time was not significantly different at any treatment concentration relative to controls. The percentage of eggs that hatched was affected at only the highest treatment level (200 ug ai/L) while both time to swim - up and fry survival (60 - d post hatch) were significantly different from controls at the two highest treatments (110 and 200 ug ai/l). Trout length (37 - d post - hat ch) and wet weight (60 - d post - hatch) were the most sensitive endpoints examined, with statisticallysignificant reductions of 1.3% and 24%, respectively , in the 12 ug ai/Ltreatment relative to negative controls. **The overall chronic NOAEC is <12 ug ai/L and LOAEC is 12 ug ai/L for**  **fish weight (60 -**  **d post -**  **hatch) and fish length (37 -**  **d post -**  **hatch) which will be used for calculating chronic risk quotients to freshwater fish.**  This study is considered supplemental because a definitive NOAEC was not achieved. **b. F**  **reshwater Invertebrates** Acute toxicity

studies of TM TGAI to freshwater (pelagic) invertebrates were available for Daphnia magna and D. pulex **( Table**  **19** ) 

### . A 48 - h EC 50 

### of 48 mg ai/L and a NOAEC of 17 mg ai/Lwere determined for D. magna on the basis of immobilization. These concentrations are 1 - 2 orders of magnitude higher than the solubility of TM in water. Even with the use of dimethylformamide (DMF) as a co - solvent, surface films and precipitation was observed in the study . There wa s no indication that samples were filtered or centrifuged prior to anal ys is. Therefore, endpoints from this study are considered uncertain with respect to the actual amount of TM that was dissolved in test media Although lack of sample centrifugation in the presence of precipitates can justify

invalidation of a study , it is highl y unlikely that the uncertainty associated with the bioavailability

of TM in this study

would change the aquatic risk conclusions due to the extremely low aquatic EECs. Therefore , this study is classified as supplemental. . A 24 - h acute toxicity test with D. pulex was also available, but it did not fulfill guideline requirements because the test was only

conducted for 24 hours. The 24 - h EC 50 

### based on organism immobility was 2.4 m g ai/L; there were also no mortalities at the highest test level (10 ppm). Although samples were not centrifuged prior to anal ys is, no solubility problems (precipitates) were reported by the**73**



### study authors. Similar to the results with freshwater fish, the degradate DM - TM was practicall y non - toxic to freshwater invertebrates as indicated by a 48 - h EC 50 

### of >95 mg/L. For risk assessment purposes, the most sensitive acute toxicity endpoint for freshwater invertebrates is a 24 - h EC 50 

### of 2.4 mg ai/L for D. pule x . Since this value exceeds the reported solubility of TM (0.7 - and 1.0 mg/L), and reflects only 24 - h exposure (not the recommended 48 hours), **an acute toxicity reference value equivalent to the solubility of TM in water (0.7 mg/L)**  **will be used for calcul ating acute risk quotients for freshwater invertebrates.**  Based on a 24 - hr EC 50 

### of 2.4 mg ai/L, TM is classified as moderatel y toxic to freshwater invertebrates on an acute exposure basis. A freshwater invertebrate ( D. magna ) lifecycle test with TM TGAI (97.6%) was submitted and found to be supplemental (raw data on reproduction were not included; MRID 41400303). Daphnids were exposed throughout their life cycle to mean - measured concentrations of TM ranging from 0.026 to 0.3 9 mg ai/L for 21 day s. Survival was significantl y different between the pooled controls and the mean measured exposure levels 0.19 and 0.39 mg/L. The mean yo ung/adult reproduction day after 21 day s was significantly greater in the solvent control (4.7 yo ung/adult reproduction day) compared to the negative control (3.8 young/adult reproduction day). Therefore, the original anal ys is of the data compared results to the solvent control, which indicated significant effects at mean - measured concentrations of 0. 062, 0.089, and 0.19 mg ai/L . Based on reproductive effects, the NOAEC and LOAEC are estimated at 0.026 and 0.062 mg ai/L . respectivel y. Raw data were not provided in the study report from which to recalculate the endpoints according to comparisons to neg ative controls (current EFED policy). However, the apparent solvent effect resulted in an increase in reproduction and the LOAEC (3.2 yo ung/reproduction day

at 0.062 ug ai/L) still represents a 15% reduction relative to the negative controls (3.8 young/reproduction day). Therefore, it is reasonable to consider the effects at 0.062 mg ai/L biologicall y significant even if recalculation resulted in no statistically significant difference relative to negative controls. **For risk assessment purposes, a chronic toxicity**  **reference value of 0.026 mg ai/L will be used for calculating chronic risk quotients for freshwater invertebrates.** 

**c. Estuarine/Marine Fish**  One study

was submitted for this taxonomic group that consisted of an acute exposure to sheepshead minnow ( Cyprinodon variegates ) to TM (MRID 48341932). In this study , no mortality or sublethal effects were reported up to and including the highest concentration tested (0.372 mg ai/L). At the highest test concentration (1.0 mg ai/L), a precipitate was observed and test concentrations were centrifuged prior to anal ysis. Results from this study indicate that TM is not acutel y toxic to sheepshead minnow at levels approaching the limit of solubility for TM in saltwater. No data were submitted on the chronic effec ts of TM to estuarine/marine fish. A waiver request for this study

was accepted on the basis of expected low likelihood of chronic effects to estuarine/marine fish in consideration based on low projected EECs in relation to available**74**



### toxicity data for fis h. Additional characterization of the uncertainty associated with the lack of chronic toxicity

data for estuarine/marine fish is provided in **Section IV.B (Risk Description)** .

**d. Estuarine/Marine Invertebrates**  Acceptable acute toxicity studies were availab le for two species of estuarine/marine invertebrates: the my sid shrimp ( Americamysis bahia ; MRID 48341929) and Eastern o ys ter ( Crassostrea virginica ; MRID 48341928). With my sids, a 96 - h LC 50 

### value of 0.327 mg ai/L was obtained which is about 2X lower than the reported solubility of TM. The solvent DMF was used in this test and no precipitates were noted in test vessels. No overt signs of toxicity were noted up to 0.121 mg ai/L, which is considered the NOAEC in this study . With the Eastern oy ster, a 96 - h EC 50 

### for shell deposition was determined . Shell growth was reduced b y 14, 21, 66 and 86% relative to controls at 0.07, 0.14, 0.28 and 0.60 mg ai/L, respectivel y (mean - measured concentrations). A solvent (DMF) was used in this study . A precipitate was ob served at the highest test concentration but analy sis of centrifuged samples yi elded similar results as uncentrifuged samples. **For risk assessment purposes, an acute toxicity reference value of 0.21 mg ai/L will be used to assess acute risks to estuarin**  **e/ ma**  **rine invertebrates.** Based on a 96 - hr EC 50 

### of 0.21 mg ai/L, TM is classified as moderately toxic to estuarine/marine invertebrates on an acute exposure basis.

**e. Benthic (Sediment Dwelling) Invertebrates**  Effects of TM on freshwater benthic invertebrates are available from two studies: a 10 - d exposure via spiked sediment to the amphipod Hyalella azteca (MRID 48341931) and a 28 - d exposure via spiked overlying water to the midge Chironomus riparius (MRID 4873 7504; **Error! Reference source not found.**  

### Table **19** ). In the first study , 7 - 14 day old H. azteca were exposed to spiked sediment concentrations of 4.8, 12, 24, 48, and 103 mg ai/kg dry w eight (mean measured). Concentrations in sediment and interstitial sediment “pore” water remained relativel y stable from day 0 to day 10. No treatment related reductions in amphipod survival or growth (dry

weight; dw) relative to negative controls occurred after 10 days exposure. On the basis of sediment dry

weight, sediment organic carbon (OC), and pore water, the NOAECs from this study are 103 mg/kg dw, 4120 mg/kg - OC, and 0.854 mg ai/L, respectively . As seen with other toxicity

studies of aquatic animals, the NOAEC from this study approximates the solubility limit of TM in water. Results from the chronic study on C. riparius indicate development rate was significantl y reduced b y 3.4% relative to negative controls at 0.188 mg ai/L porewater, resulting in a NOAEC of 0.013 mg ai/Lpore water (0. 186 mgai/kg dw in sediment, 7.7 mg ai/kg - OC). This NOAEC is substantially

lower than the 10 - d NOAEC obtained for H. azteca (0.013 mg ai/L pore water for midge vs. 0.854 mg ai/L pore water for amphipod; **Error! Reference sourc e not found.**  

### Table **19** ). This lower NOAEC likely reflects a combination of factors including interspecies differences in sensitivity

to TM, inclusion of a longer exposure duration, and measurement of additional**75**



### endpoints ( e.g ., development rate). It is important to note, however, that this study involved exposure via the overl yi ng water and concentrations varied considerabl y over time. Specifically, both pore water and sedim ent concentrations increased dramaticall y from day 0 to day 14, while overlying water concentrations decreased, thus reflecting the expected partitioning of TM to sediments from the water column. Although the test guideline followed in this study (OECD 219 ) is designed to mimic a spray drift event, spray

drift is not expected for the proposed uses of TM (seed treatment). OSCPP test guidelines recommend that sediments be equilibrated with test compound prior to testing and Agency- wide guidelines (USEPA 2000 ) recommend inclusion of reproductive effects as measurement endpoints in Chironomus chronic tests. Inthis study , midges were added 24 hours after addition of the test substance to sediment. Therefore, this study is classified as supplemental . The effects of TM on the saltwater amphipod, Leptocheirus plumulosus , were examined in a series of two 10 - d spiked sediment exposures (MRID 48341935). In the first exposure series, amphipods were exposed to mean - measured concentrations of 5.3, 11, 23, 48 and 97 mg a.i./kg dw plus solvent and negative controls. However, the lowest test concentration (5.3 mg ai/dw) resulted in statistically- significant effects on amphipod survival (61% of amphipods survived at this concentration). Therefore, another study w as conducted in which amphipods were exposed to 0.45, 1.1 and 2.1 mg ai/kg dw plus solvent and negative controls for 10 day s. In this study , no statistically- significant effects occurred relative to controls ( > 95% survival at the highest test concentratio n.) The pore water concentration corresponding to this NOAEC is 0.38 mg ai/L , which is about half the limit of solubility for TM. The NOAEC in sediment is 2.1 mg ai/kg dw and 75 mg ai/kg - OC when normalized to 100% organic carbon. Although in combination both test series can be used to identify a definitive NOAEC, the fact that neither test series resulted in a NOAEC that was bounded with a LOAEC introduces uncertainty in the estimated NOAEC. For example, different groups of organisms from in - house cultures were used to test TM at different times. Therefore, this study is c lassified as supplemental. **f. Aquatic plant**  Of the two aquatic plant toxicity studies submitted on TM TGAI using freshwater green algae ( Pseudokirchneriella subcapitata ), the most sensitive yielded a 72 - hr EC 50 

### of 0.78 mg ai/Land a NOAEC of 0.18 mg/L . A toxicity test of the degradate DM - TM with P. subcapitata indicated that the degradates was less toxic to green algae (96 - hr EC 50 

### >97 mg ai/L ; NOAEC=12 mg ai/L) by several orders of magnitude. There is uncertainty though regarding the effects to other nonvascular plants (algae) as only one rather than the four species recommended in OPPTS Guideline 850.5400 was tested. Additionally , there is uncertainty regarding the potential effec ts of TM on vascular aquatic plants (OPPTS Guideline 850.4400) as no data are available. However, a recent anal ys is conducted to support a data waiver request for additional aquatic plant data suggests that additional data for aquatic plants would have a low potential to affect risk assessment conclusions (D393184). Additional discussion of the uncertainty associated with the lack of a full aquatic plant data set is provided in **Section IV.C.**

**2. Terrestrial Effects** **76**



### All toxicity

reference values used to assess the potential acute and chronic risks of TM exposure to mammals were obtained from acceptable or supplemental studies using TM TGAI submitted to the OPP Health Effects Division (HED) for r eview **.** No data on the toxicity of TM degradates to terrestrial plants and animals were submitted. Acute and chronic data for other terrestrial taxa were reviewed b y EFED and the resulting endpoints are reported in **Table 20**  . A brief summary of these studies follows this table, with detailed summaries provided in **Appendix D. Table**  **20 . Toxicity Reference Values For Terrestrial Org**  **anisms Exposed To Tolclofos Methyl Exposure**  **Scenario % A.I.**  **Species Dur.**  **Toxicity Reference Value** ** **(95% CL) Effect Notes**  **MRID; Classifi**  **** **cation Avian Toxicity** 

**Acute** TGAI

9 9.8 % Mallard Duck Anas platyrhynchos (Acute Oral) 14 d LD 50 > 5000 mg ai/kg bw NOAEL =5000 mg ai/kg bw  No mortalities in control or at the 5000 mg/kg test level.  Weight changes were variable for all birds, but within normal limits. 00156112 Acceptable Roberts and Haskins (1981) TGAI 97.7% Mallard Duck A. platyrhynchos (Subacute, Dietary) 8 d **LC 50**  **>5620 m g ai/k** **g diet**  NOAEL = 5620 mg ai/kg diet  No mortalities occurred at any test concentration  Food consumption and weight gain were similar at all test levels. 00156115 Acceptable Beavers (1985)
TGAI 99.8% Bobwhite Quail

Colinus virginianus (Acute Oral) 14 d LD 50 >5000 mg ai/kg bw NOAEL = 5000 mg ai/kg bw  No mortalities in control or at the 5000 mg/kg test level.  Weight changes were variable for all birds, but within normal limits. 00156113 Acceptable Roberts and Haskins (1982) TGAI 97.7% Bobwhite Quail

C.virginianus (Subacute Dietary) 8 d LC 50 = >5620 mg ai/kg diet NOAEL = 5620 mg ai/kg diet  No mortalities at the 562, 1780, 3160 and 5620 ppm levels.  A total of 6/50 (12%) of control birds died which was attributed to aggression  There was 20% mortality (2 of 10) at the 1000ppm level but this did not appear treatment related.  There was no apparent effect on body weight or feed consumption at any treatm ent level. 00156116 Acceptable Beavers (1985)

TGAI 99.8% Ring - necked

Pheasant Phasianus colchicus (Acute Oral) 14 d LD 50 >5000 mg ai/kg bw NOAEL = 5000 mg a.i./kg bw  One mortality (5%) occurred of the 20 test birds at the 5000 mg/kg test level. This was considered a result of aggression, not test treatment.  No treatment - related impact was observed on body weights, which appeared variable but within normal limits. 0015611 4 Accep table Roberts and Haskins (1981)**77**

**Table 20**  **. Toxicity Reference Values For Terrestrial Org anisms Exposed To Tolclofos Methyl**  **Exposure Scenario**  **% A.I. Species**  **Dur. Toxicity Reference**  **Value  ** (95% CL)** **Effect Notes MRID;**  **Classifi**   ** cation** TGAI 95.6% Zebra Finch Poephilia guttata 14 d **LD 50**  **>2000 m g ai/k** **g bw**  LOAEL= >2000 mg ai/kg bw NOAEL= 2000 mg ai/kg bw  No mortality, change in body weight or clinical signs of toxicity occurred at the limit dose (2000 mg ai/kg bw).  However, regurgitation occurred in 2 (17%) of the test animals in the nominal 2000 mg ai/kg bw treatment group within the first hour of dosing  Gi ven that the remaining 10 birds that did not regurgitate the test material and no other lethal or sublethal effects occurred, the LD50 is considered > 2000 mg ai/kg bw. 48341936 Acceptable (2010)

**Chronic** TGAI

97.7% Mallard Duck A. platyrhynchos 12 wk LOAEL=2500 mg ai/kg diet **NOAEL=500 m g ai/k** **g diet**   At 500 ppm, no treatment related mortalities or overt signs of toxicity occurred.  At 2500 ppm, 3 of the 32 adults died and significant reductions (up to 50% of controls) occurred in # eggs laid/set; viab le embryos and egg hatch.  At 7500 ppm, 10 of 32 adults died. At both 2500 and 7500, lower limb weakness and other toxic symptoms were observed. 40190202 Acceptable (Beavers et al . 1987)

TGAI 97.7% Bobwhite Quail

C. virginianus 13 wk LOAEL=2500 mg ai/kg diet NOAEL= 500 mg ai/kg diet  A significant reduction in the number of eggs laid, eggs set, viable em bryos live embryos and eggs hatched occurred in both the 2500 and 7500 ppm concentrations.  No clinical signs of toxicity occurred at 500 ppm diet. 4 0190201 Acceptable Beavers and Jaber (1987)

**Mam mals** 

**Acute** TGAI

97.7% Rat

(Rattus norvegicus) 14 d LD 50 >5000 mg ai/kg bw (both sexes)  No mortality, change in body weight at the limit dose (5000 mg ai/kg bw).  sublethal signs of toxicity (e.g., hunched posture) occurred but full recovery was observed by day 5 00156124 Acceptable (Kynoch 1985) Rat (R. norvegicus) 14 d LD 50 = 4900 mg ai/kg bw (both sexes) Probit Slope: n/a NOAEC = 2500 mg ai/kg bw  55% mortality (11/20) at the highest treatment (5000 mg ai/kg bw).  Sublethal effects occurred at 3750 and 5000 mg ai/kg bw. 00156128 Acceptable (Segawa et al. 1978) TGAI 97.0% Mouse

(Mus musculus) 14 d **LD 50**  **=3500 m g ai/k** **g bw**  **(males) (2760 -**  **4800)** LD 50 =3600 mg ai/kg bw (females; 2710 - 4790) Probit slope: n/a/ NOAEC =1000 mg ai/kg bw  10, 20, 30 and 60% mortality occurred at 1500, 2000, 3000, and 4000 mg ai/kg bw, respectively.  Clinical signs of toxicity > 1500 mg ai/kg included ataxia, irregular respiration, decreased motor activity 00156128 Acceptable (Segawa et al . 1978)**78**

**Table 20**  **. Toxicity Reference Values For Terrestrial Org anisms Exposed To Tolclofos Methyl**  **Exposure Scenario**  **% A.I. Species**  **Dur. Toxicity Reference**  **Value  ** (95% CL)** **Effect Notes MRID;**  **Classifi**   ** cation**

**Chronic** TGAI

94.9% Rat

(R.norvegicus) Dvlp* NOAEL =300 mg/kg bw/d LOAEL = 1000 mg ai/kg bw/d  Rats dose with 0, 100, 300, and 1000 ppm (D6

– D15 of gestation via gavage).  No treatment related effects on survival, body weight, food consumption, histopathology  Significant increase in skeletal deformation (unossification of 6 th sternebrae) of fetus at 1000 ppm highest dose (12%) vs. control (4%) 41422901 Acceptable (Morseth 1987)

TGAI 98.7% Beagle dog

(C. lupus familiaris) 6 mo NOAEL = The NOAEL is 600 ppm (23/20 mg/kg/day M/F).  At 2000 ppm diet, decreased body weight gain, hematocrit, hemoglobin erythrocyte count. In addition, alkaline phosphatase and absolute and relative liver weight were significantly increased.  Plasma cholinesterase activity was significantly depressed in hi gh dose females at all reporting periods (4 - 24 wks) . 00156138 Supplemental (Pence et al . 1979)

TGAI 97% Mouse M. musculus 9 mo **NOAEL = 100 ppm (13.8 and 12.2 m**  **g ai/kg bw for M/F)**   Oral dietary exposure to 0, 10, 30, 100, and 3000 ppm  Significantly lower weight gain in males and females at 3000 ppm (503 mg ai/kg bw)  Cholinesterase inhibition in 30, 100 and 3000 ppm in females (plasma) at study termination (9 mo) 00156137 Supplemental (Suzuki et al. 1978)

**Nontarget Insects -**  **Bees**

**Acute** TGAI

97.7% Honeybee Apis

mellifera 48 h **LD 50**  **>100 ug ai/bee**  Mortality was 4% or less at 13, 22, 36, 60, and 100 ug ai/bee  Mortality in the negative and solvent controls was 2% and 10% respectively. 41794202 Acceptable Winter et al (19 90 ) TGAI 97.6% Honeybee A.

mellifera 24 h LD 50 >100 ug ai/bee  Mortality was 0% at 12.5 and 50 ug ai/bee; 6.7 and 16.7% at 25 and 100 ug ai/bee.  No information on whether a control was used was indicated by the study authors. 00163557 Supplemental (1983) **Nontarget Terrestrial Plants (**No data; waiver request accepted)* *W aiver request accepted for terrestrial plant toxicity studies (D393184) ** Toxicity endpoints in bold are those used for RQ calculation**79** 

### a. **Birds (Acute Toxicity)** Acute oral and subacute dietary toxicity studies are available for four avian species, i.e .,bobwhite quail ( Colinus virginianus ) , ring - necked pheasant ( Phasianus colchicus ) , mallard duck ( Anas platyrhynchos ) , zebra finch ( Poephilia guttata ) represent three orders of birds, i.e, Galliformes, Anseriformes, and Passeriformes ( **Table 20**  ). Overall, these studies indicate that, based on the t oxicity classification scheme used b y EFED, TM is practicall y non - toxic, i.e., LD 50 

### >2000 mg ai/kg bw, to these species of birds on an acute exposure basis. For bobwhite, ring - necked pheasant, and mallard, no treatment - related mortality occurred at the highest dose tested (Accession No. 00156112 , 00156113 , 00156114 ). Furthermore, no treatment - related sublethal signs of toxicity

( e.g ., adverse effects on body weight, food consumption) were reported in these studies. Similarly

for zebra finch, no treatment related effects on mortality, body weight or clinical signs of toxicity

occurred at the limit dose (2000 mg ai/kg bw). Within the first hour of dosing, 2/12 finches regurgitated at the limit dose. However, none of the remaining birds regurgitated or sho wed other sublethal signs of toxicity . Therefore, the finch study validity is not considered to be impacted by this low rate of regurgitation. **For risk assessment purposes, an acute oral**  **LD 50**  

### of >2000 mg ai/kg bw) for passerines will be used **qualitatively to evaluate potential acute effects to birds (**  **i.e ., a**  **value of 2000 mg ai/kg bw will be assumed as a screen**  **for acute effects).** Based on an 14 - day LD 50 

### >2000 mg ai/kg bw for zebra finches, TF is classified as practicall y non - toxic to birds on an acute oral exposure basis. For bobwhite quail and mallard, the subacute dietary LC 50 

### is >5260 mg ai/kg diet since no treatment - related mortality occurred at the highest concentrations tested. In the bobwhite quail study , control mortality (12%) was greater than normally accepted. However, this was attributed to aggression (evidenced by toe picking) in 2 of the 5 control replicates. Furthermore, no mortalities occurred at the lowest test level, 562 ppm, or at the 1780, 3160 and 5620 ppm levels. No a pparent effect of TM on body weight or food consumption was observed at any treatment level. For mallard, no mortality occurred in controls or in any treatment level tested. **For risk assessment purposes, an acute oral LC**  **50** 

### of >5260 ppm in the diet) will **be used qualitatively to evaluate potential acute effects to birds (i.e., a lower bound of 5260 ppm will be assumed**  **as a screen for acute effects).** Based on an 8 - day L C 50 

### >5260 mg ai/kg diet for mallard duck, TF is classified as practically non - toxic to bi rds on a subacute dietary exposure basis. **b. Birds (Chronic Toxicity)**  Two studies were submitted that examined the chronic toxicity of TM to avian species ( **Table 20**  ). In the study with mallards, Beavers et al . (1987; MRID 40190202) 41 - week old mallards (3 groups of 16 replicate pairs/group) approaching their first breeding season were fed a diet contain ing 500, 2500 or 7500 ppm of TM (97.7% ai). A fourth group was fed a control diet containing 0.09% corn oil, the amount used as a carrier for the test material. No treatment - related mortalities or overt signs of toxicity occurred at 500 ppm. At 2500 ppm, 3 (9.3%) of the 32 adults died; and at 7500, 10 died (31%). At both 2500 and 7500, lower limb weakness and other toxic sy mptoms were observed. Analy sis of variance indicates that at 2500 ppm, statistically**80**



### significant reductions were observed in number of eg gs laid, eggs set, viable embryos, and eggs hatched. The NOAEC from this study is 500 mg ai/kg - diet. In the study of bobwhite quail, Beavers et al . (1987 MRID 40190201) fed 22 - week old quail (3 groups of 16 replicate pairs/ group) approaching their first breeding season a diet containing 500, 2500 or 7500 ppm of TM (97.7% ai). A fourth group was fed a control diet containing 0.09% corn oil, the amount used as a carrier for the test material. No treatment - related mortalities or overt signs of toxicity

occ urred. There were no statistically significant differences in adult body weight of males between control and any treatment groups. Females at 7500 ppm exhibited a slight (5%) , but statistically significant reduction of body weight during week 7. Feed consumption appears to have been reduced at the 7500 ppm level. There was no apparent effect on treatment parameters or sublethal effects at the 500 ppm concentration. When compared to the control group, there was a significant reduction in the number of eggs l aid in both the 2500 and 7500 ppm concentrations. The reduction in number of eggs laid (22% & 3%) resulted in a reduced number of eggs set (25% & 11%) , viable embryos (20% & 10%) , live embryos (20% & 11%) and eggs hatched (23% & 40%) relative to controls at the 2500 and 7500 ppm levels , respectivel y . There was no apparent effect on cracked eggs. The NOAEL for TM in this study is 500 ppm. **The dietary chronic NOAEL of 500 ppm will be used for calculating chronic risk quotients to avian species.**  **c. Mammals (acu**  **te toxicity)** For evaluating acute oral toxicity, four studies were available for rat, mouse and dog ( **Table 20**  ). All studies with mammals indicated TM was practically nontoxic or at most, slightly toxic to mammals on an acute oral exposure basis. In the first of two acute oral studies conducted with rats ( Rattus norvegicus ), Segawa et al . (1978; Accession No. 00156128) exposed groups of 10 male and 10 female Sprague - Dawley (SD) strain rats via gavage to TM (97.0% ai) to 1000, 2500, 3750, and 5000 mg ai/kg bw and followed the animals for 14 day s. At the highest dose (5000 mg ai/kg bw), 5 males and 6 females we re found dead within 1 - 5 day s post - treatment. Clinical signs of toxicity occurred in rats dosed at 3750 and 5000 mg ai/kg bw and included decreases in spontaneous motor activity, irregular respiration, piloerection, urinary incontinence and hind - limb atax ia. The 14 - day LD 50 

### was calculated to be 4900 mg ai/kg bw (both sexes combined). No visible lesions were evident at gross necrops y. Ky noch 1985 (Accession No. 00156124) also investigated the acute toxicity of TM technical in SD rats. After a range f

inding study , a limit test was conducted using a single dose of 5000 mg ai/kg bw (97.7%) to 5 male and 5 female rats. No mortality occurred for either male or female rats 14 day s after dosing. Clinical signs of toxicity were observed in all animals teste d and included piloerection and hunched posture shortl y after dosing with complete recovery in 5 day s. Body weight gains were observed in all test animals and at sacrifice none of these animals had any abnormal gross morphological lesions. Thus, the acute oral LD 50 

### for male and female rats was >5,000 mg ai/kg.**81**



### T oxicity was observed with mice ( Mus musculus ) on an acute oral exposure basis as that described above for rats. Specificall y, Segawa et al . 1978 (Accession No. 00156128) exposed 10 male and 10 fem ale mice to TM at doses of 1000, 1500, 2000, 3000, 4000 mg ai/kg bw. After 14 day s, mortality

at these doses (from low to high) was 0, 5, 15, 25 and 60% respectively and was similar for both sexes. Mice (male and female) receiving 1500 mg ai/kg or higher exhibited the same signs of toxicity as those reported for rats by the same authors (see above). The 14 - day acute oral LD 50 

### for male mice was 3500 mg ai/kg and 3600 mg ai/kg for male and female mice, respectivel y. Based on a 14 - day

acute oral LD 50 

### of 3 500 mg ai/kg bw for mice, TM is classified as practicall y non - toxic to mammals on an acute exposure basis. **d. Mammals (chronic toxicity)**  Although several studies were available on the chronic oral toxicity of TM to rats and mice that included effects on reproduction, most were considered by HED to be invalid due to study performance issues. Therefore, for assessing ecological risks to mammalian wildlife, the most appropriate studies identified among submitted studies include a developmental toxicity study with rat, a 6 - month dietary study with dog and a 9 - month subchronic dietary exposure study with mice ( **Error! Reference source not found.** 

### Table **20 .**  

### ). Morseth 1987(MRID 41422901) evaluated the developmental toxicity of TM to rats. TM (94.9% ai) was administered b y gavage to rats on gestation day s 6 through 15, inclusive at doses of 0, 100, 300, and 1000 mg /kg bw/d. No clinical signs of toxicity were noted during the study . No fetal deaths were reported in any of the groups. There was a non - significant dose - related decrease in corrected body weight gains during the dosing period an d during the entire gestation period, when compared to the controls. The onl y finding of statistical significance was unossified 6 th 

### sternebra, at the 1,000 mg/kg/day group when compared to the controls. The NOAEL from this study is 300 mg ai/kg bw/d base d on skeletal abnormalities in developing rats. Pence et al . 1979 (Accession No. 00156138) examined the effect of TM (98.7%) on beagle dogs fed diets spiked with 0, 200, 600, and 2000 ppm TM over 6 months. Animals (6/treatment) were 5 - 7 months old rangin g in weight from 6.7 to 12.4 kg in males, and 5.8 to 10.2 kg in weight for females. The following parameters were depressed at 2000 ppm at test termination : body weight gain, hematocrit, hemoglobin and ery throcy te count. In addition, alkaline phosphatase and absolute and relative liver weight were significantly increased in high dose males and females. Relative to controls, p lasma cholinesterase activity was significantly

depressed by

19 - 27% in high dose females at all reporting periods (4 - 26 wks) . No comp ound related gross or microscopic lesions were reported. Based on these findings, the NOAEL is 600 ppm which corresponds to 20 and 23 mg ai/kg bw/d for males and females respectively . In the subchronic oral toxicity study with mice, Suzuki et al . 1978 (M RID 00156137) fed 15 male and 15 female mice a diet containing 0, 10, 30, 100, and 3000 ppm TM (97% ai) for 90 day s. All animals survived the study , and no abnormal clinical signs were reported. Both body weight and body weight - gain were reduced in the highest dosage group (3000 ppm), although**82**



### food consumption was increased in these groups. At 3000 ppm, body weights of males and females at the highest dose group were about 20% reduced relative to controls. The only other significant toxicity

observed in this study

was plasma cholinesterase inhibition in female mice at doses of 30 ppm and above at test termination (9 mo) . **Fo r ecological risk assessment**  **purposes, a NOAEL of 100 ppm in the diet (13.8 mg ai/kg bw for males, 12.2 mg ai/kg bw for females) is**  **determined from this study.**

**e. Non**  **- target Beneficial Insects**  Two studies were submitted that examined the acute contact toxicity of TM to young adult honey bee ( Apis mellifera ; **Error! Reference source not found.** 

### Table **20 .**  ). The first study , conducted in 1983, examined contact exposure of bees to TM (97.6% ai) for 24 hours (Accession N o. 00163557). A maximum of 16.7% mortality occurred at the limit dose (100 ug ai/bee) thus yi elding a 24 - hr LD 50 

### of >100 ai/bee. Because the exposure duration was just 24 hours (rather than the 48 hours recommend in the 850.3020 test guidelines, and info rmation on control performance was not provided, this study is considered supplemental. The second study , conducted for the recommended 48 hours in 1987, corroborated the results from the first study (MRID 41794202). The maximum mortality was 4% up to 10 0 ug ai/bee and < 10% in the controls. The 48 - hr acute contact LD 50 

### is therefore >100 ug ai/bee which classifies TM as practicall y non - toxic to young adult bees on a acute contact exposure basis. **f. Terrestrial Plants**  No toxicity

data are available for terre strial plants . However, a recent anal ysis conducted to support granting a data waiver request for terrestrial plant data suggests that additional data for terrestrial plants would have a low potential to affect the risk assessment conclusions (D393184). Additional discussion of the uncertainty associated with the lack of a terrestrial plant data is provided in **Section IV.C.** .**83**



## IV. **RISK CHARACTERIZATION**  Risk characterization is the integration of exposure and effects characterization to determine the potential ecological risk from the proposed use of TM as a seed treatment and the likelihood of adverse effects on aquatic life, wildlife, and plants based on varying pesticide - use scenarios. The risk characterization pro vides estimation and a description of the risk; articulates risk assessment assumptions, limitations, and uncertainties; sy nthesizes an overall conclusion; and provides the risk managers with information to make regulatory decisions. **A. Risk Estimation**  **- Int**  **egration of Exposure and Effects Data** Results of the exposure and toxicity effects data are used to evaluate the likelihood of adverse ecological effects on non - target species. As discussed in the Problem Formulation, for the assessment of TM risks, the risk quotient method is used to compare exposure and measured toxicity values (refer to **Appendix E** ). Estimated environmental concentrations are divided b y the most sensitive acute and chronic toxicity values. The RQs are then compared to the Agency ’s levels of concern. These LOCs, summarized in **Appendix E** , are the Agency’s interpretive policy

and are used to anal yz e potential risk to non - target organisms and the need to conside r regulatory

action. These criteria are used to indicate when a pesticide’s use as directed on the label has the potential to cause adverse effects on non - target organisms.

**1. Non**  **- target Aquatic Animals and Plants**  To assess risk of TM to non - target aquatic animals and plants, surface water, pore water and sediment EECs for TM were obtained from the Tier 2 models PRZM and EXAMS based on the label - recommended usage scenarios ( **Table 3**  ). As discussed in **Section III.B** , two different TM use assumptions were used to generate aquatic EECs: **Case 1 (Most Conservative):** Assuming that the application of TM - treated seeds results in the maximum application rate 0.02 lb ai/A specified on the label for all crops, irrespective of the realism in the seeding rate needed to achieve this maximum application rate; and, **Case 2 (Most Realistic):** Using realistic (BEAD re commended) seeding rates specific for each crop combined with label recommended seed treatment rates (mg ai/100 kg seed). Case 1 results in the highest aquatic EECs, but in some cases, it requires unrealistically- high seeding rates to achieve the 0.02 lb ai/A maximum allowable rate specified on the label. Case 2 results in equal (some crops) or lower (most crops) aquatic EECs, but the seeding rates used are considered realistic high - end rates.

**a. Water Column Exposure: Acute and Chronic Risk to Animals** **84**



### Fish Risk quotients for evaluating the potential for fish to be exposed to acutely toxic concentrations of TM were determined as the ratio of the 1 - in - 10 year maximum daily EEC to the appropriate acute toxicity

reference value (96 - hr LC 50 

### =690 and >372 ppb for fresh and saltwater fish, respectivel y) described in **Section III.B** . Risk quotients for evaluating the potential of fish to be exposed to chronically

toxic concentrations of TM were determined as the ratio of the 1 - in - 10 ye ar maximum 60 - day

average EEC to the appropriate chronic toxicity reference value (NOAEC<12 ug ai/L) for freshwater fish. A total of 65 acute and chronic EECs were derived using the exposure assumptions of C ase 1 (using the most conservative use rate assumptions) and 171 EECs were derived for Case 2 (using the most realistic use rate assumptions). Of these, the greatest peak EEC in surface water is **0.34 4**  **ppb** for Case 1 ( **Table 15**  ) and **0.148 ppb** for Case 2 ( **Table 16**  ). These maximum peak EECs were model ed with the Florida Carrots exposure scenario (Case 1) and the Georgia Onion w/ irrigation exposure scenario (Case 2). Maximum 60 - d average EECs using Case 1 resulted from the Florida Pepper scenario ( **0.147 ppb)** while that for Case 2 resulted from the Geo rgia Onion w/ irrigation crop exposure scenario ( **0.060 ppb**  ). Overall maximum acute and chronic RQs for fish determined from all the crop exposure scenarios are provided in **Table 21**  **.** The maximum acute RQs are at least two orders of magnitude below the acute risk LOC . For saltwater fish, the acute LC 50 

### value was non - definitive (>372 ug ai/L). Therefore, a definitive RQ is not able to be calculated; however it is known to be less than <0.0008 (Case 1) and <0.0004 (Case 2). For chronic RQs, data were available onl y for freshwater fish. For this risk assessment, re - anal ysis of the toxicity data yi elded a NOAEC of <12 ug ai/L . Therefore, the actual chronic RQ is unknown, but is known to be >0.008 (Case 1) and >0.005 (Case 2). The uncertainty in these upper and lower bound RQ values is discussed further in **Section IV.B (Risk Description** ). **Table 21**  **. Acute and chronic risk quoti ents (RQs) for evaluating toxic risk of TM exposure to**  **freshwater and saltwater fish Organis**  **m LC**  **50**

**(μg a.i./L) b**  **NOAEC**

**(μg a.i./L) b**  **EEC c** 

**Peak (μg a.i./L)**  **EEC c** 

**60 -**  **Day (μg a.i./L)**  **Acute**

**RQ (peak**  **EEC/LC 50**  **) Chronic** 

**RQ (60**  **- day**  **EEC/NOAEC)** Freshwater Fish (Case 1) a 690 <12 0.343 0.147 0.0005 >0.01 Freshwater Fish (Case 2) a 0.148 0.060 0.0002 >0.005 Saltwater Fish (Case 1) a >372 Not available 0.343 0.147 <0.0009 Not calculated Saltwater Fish (Case 2) a 0.148 0.060 <0.0004

a Aquatic EECs (TM+bound residue) derived according to “Case 1” are based on the maximum allowable application rate (0.02 lb ai/A), regardless of seeding rate necessary to achieve this application rate ( **Table 15**  **)** . Aquatic EECs derived according to “Case 2” are based on the maximum allowable seed treatment rates (i.e., mg ai/100 kg seed) and the realistic estimate of seeding rates specific to the crop or crop group ( **Table 16**  **). b**  Toxicity reference values from **Error! Reference source not found. Table**  **19 .**  

### A cumulative frequency

distribution of acute RQs for fish derived using each crop exposure**85**



### scenario is shown in **Figure 9**  and displayed relative to risk to acute listed (0.05) and non - listed (0.5) species LOCs. It can be readil y seen from this figure that aquatic RQs are 2 - 3 orders of magnitude below the acute risk LOCs for freshwater fish and at least the same for saltwater fish.

**Figure 9**  **. Acute Risk Quotients for Freshwater Fish (top panel) and Saltwater Fish (bottom panel) Relative to LOCs (0.5=listed sp.; 0.05 = non**  **- listed sp.)**  **Dow nward arrows denote non**  **- definitive**  **RQs (“<” values)** 

### A cumulative frequency

distribution of chronic RQs for freshwater fish derived using each crop exposure scenario is shown in **Figure 10**  

### relative to the chronic risk to listed and non - listed speciesLOC (1.0). Since these RQs are based on a non - definitive chronic NOAEC for **1.0E -**  **07 1.0E**  **- 06**  **1.0E -**  **05 1.0E**  **- 04**  **1.0E -**  **03 1.0E**  **- 02**  **1.0E -**  **01 1.0E**  **+00**



### 0% **20% 40%**  **60% 80%**  **100% R** **i s** **k Q** **u o** **t i** **e n** **t**



### Cum **ul at**  **iv e**  **Fr eq**  **ue nc**  **y** 

## FW**F ish**  **( Acu**  **te)**

Ca se 1 Ca se 2 No n - list ed S p. LOC Lised S p. LOC

**1.0E -**  **07 1.0E**  **- 06**  **1.0E -**  **05 1.0E**  **- 04**  **1.0E -**  **03 1.0E**  **- 02**  **1.0E -**  **01 1.**  **0E +00** 



### 0% **20% 40%**  **60% 80%**  **100% R** **i s** **k Q** **u o** **t i** **e n** **t**



### Cum **ul at**  **iv e**  **Fr eq**  **ue nc**  **y** 

## SW **Fish (**  **Ac ut**  **e)**

Ca se 1 Ca se 2 No n - list ed S p. L OC Lised S p. LOC**86**



### freshwater fish (<12 ug ai/L), onl y the lower bound of the chronic RQ can be described with certainty (i.e., that it is greater than the value shown) . Th erefore , the actual RQ could conceivabl y exceed the chronic risk LOC depending on the value of the definitive NOAEC. This is denoted by

the upward facing arrows on **Figure 10**  . Although such non - definitive (“greater than”) RQs are not traditionally determined in EFED ecological risk assessments, they are shown here b ecause the lower bound of these chronic RQs ( i.e ., RQs that are based on the LOAEC of 12 ug ai/L) are at least two orders of magnitude below the chronic risk LOC. The likelihood of the actual NOAEC occurring two orders of magnitude below the LOAEC of 12 u g ai/Lis discussed in **Section IV.B (Risk Description)** .

**Figure 10**  **. Chronic Risk Quotients for Freshwater Fish Relative to LOC (1.0). Upward arrows denote non**  **- definitive RQs (“>” values).**  

### Aquatic Invertebrates - Water Column Maxi mum acute and chronic RQs for aquatic invertebrates are determined from the 1 - in - 10 year maximum daily

and 1 - in - 10 year maximum 21 - d average EECs and the appropriate toxicity reference values ( **Table 22**  **).** The maximum acute RQs are approximately two orders of magnitude below the listed species acute risk LOC (0.05) for freshwater and saltwater invertebrates, respectively for case 1 . The maximum chronic RQs are approximately two orders of magnitude below the chronic risk LOC for freshwater and saltwater invertebrates, respectivel y. **Table 22**  **. Maximum Acute and chronic risk quotients (RQs) for evaluating toxic**  **risk of TM exposure to freshwater and saltwater invertebrates**  **Organis m**  **EC 50**  **(μg a.i./L) b**  **NOAEC**

**(μg a.i./L) b**  **EEC**

**Peak (μg a.i./L)**  **EEC**

**21 -**  **Day (μg a.i./L)**  **Acute**

**RQ (peak**  **EEC/LC 50**  **) Chronic** 

**RQ (21**  **- day**  **EEC/NOAEC) 1.0E**  **- 06**  **1.0E -**  **05 1.0E**  **- 04**  **1.0E -**  **03 1.0E**  **- 02**  **1.0E -**  **01 1.0E**  **+00**



### 0% **20% 40%**  **60% 80%**  **100% R** **i s** **k Q** **u o** **t i** **e n** **t**



### Cum **ul ative**  **Fr eq**  **ue nc**  **y** 

## FW**F ish**  **( Chroni**  **c)** Ca se 1 Ca se 2 Chr oni c LOC = 1**87**

**Table 22**  **. Maximum Acute and chronic risk quotients (RQs) for evaluating toxic**  **risk of TM exposure to freshwater and saltwater invertebrates**  Freshwater Inverts. (Case 1) a 700 26 0.34 4 0.209 0.00 05 0.008 Freshwater Inverts. (Case 2) a 0.148 0.093 0.000 2 0.004 Saltwater Inverts. (Case 1) a 210 3.9 0.34 4 0.209 0.0016 0.05 Saltwater Inverts. (Case 2) a 0.148 0.093 0.0007 0.024

a Aquatic EECs (TM+bound residue) derived according to “Case 1” are based on the maximum allowable application rate (0.02 lb ai/A), regardless of seeding rate necessary to achieve this application rate ( **Table 15**  **)** . Aquatic EECs derived according to “Case 2” are based on the maximum allowable seed treatment rates (i.e., mg ai/100 kg seed) and the realistic estimate of seeding rates specific to the crop or crop group ( **Table 16**  **). b**  Toxicity reference values from **Error! Reference source not found. Table**  **19** . 

### A cumulative frequency

distribution of acute and chronic RQs for aquatic invertebrates derived using each crop exposure scenario is shown in **Figure 11**  

### and **Figure 12**  

### , respectivel y. Acute RQs are below the acute risk to listed species LOC (0.05) by approximately two orders of magnitude for freshwater and saltwater invertebrates. Chronic RQs for aquatic i nvertebrates are at least two orders of magnitude below the chronic risk LOC (1.0) for freshwater invertebrates and one order of magnitude for saltwater invertebrates.**88**

**Figure 11**  **. Acute Risk Quotients for Freshwater (top panel) a nd Saltwater Invertebrates (bottom**  **panel) Relative to Acute Risk LOCs (0.05 and 0.5). 1.0E**  **- 07**  **1.0E -**  **06 1.0E**  **- 05**  **1.0E -**  **04 1.0E**  **- 03**  **1.0E -**  **02 1.0E**  **- 01**  **1.0E +00** 



### 0% **20% 40%**  **60% 80%**  **100% R** **i s** **k Q** **u o** **t i** **e n** **t**



### Cum **ul at**  **iv e**  **Fr eq**  **ue nc** **y**



## FW**I nv**  **ert. (**  **Acu te)** 

Ca se 1 Ca se 2 No n - list ed Sp . LOC Lised S p. L OC

**1.0E -**  **06 1.0E**  **- 05**  **1.0E -**  **04 1.0E**  **- 03**  **1.0E -**  **02 1.0E**  **- 01**  **1.0E +00** 



### 0% **20% 40%**  **60% 80%**  **100% R** **i s** **k Q** **u o** **t i** **e n** **t**



### Cum **ul at**  **ive Fr**  **eq ue**  **nc y** 



## SW**I nv**  **ert. (**  **Acu te)** 

Ca se 1 Ca se 2 No n - list ed S p. L OC Li sed S p. L OC**89**

**Figure 12**  **. Chronic Risk Quotients for Freshwater (top panel) and Saltwater Invertebrates (bottom panel) Relative to the LOC (1.0).**  

### b. **Sediment Exposure: Acute and Chronic Risk to Benthic**  **Invertebrates** Comparisons of EECs and sediment toxicity endpoints are provided below to supplement risk estimation to water column organisms. The evaluation of risk to the benthic organisms was **1.0E -**  **06 1.0E**  **- 05**  **1.0E -**  **04 1.0E**  **- 03**  **1.0E -**  **02 1.0E**  **- 01**  **1.0E +00** 



### 0% **20% 40%**  **60% 80%**  **100% R** **i s** **k Q** **u o** **t i** **e n** **t**



### Cum **ulat iv**  **e Fr**  **eq ue**  **nc y**  

## FW**I nv**  **ert. (**  **Chr oni**  **c)** Ca se 1 Ca se 2 Chroni c LOC=1.0

**1.0E -**  **05 1.0E**  **- 04**  **1.0E -**  **03 1.0E**  **- 02**  **1.0E -**  **01 1.0E**  **+00**



### 0% **20% 40%**  **60% 80%**  **100% R** **i s** **k Q** **u o** **t i** **e n** **t**



### Cum **ulative Fr**  **eq ue**  **nc y**  

## SW **Inve rt.**  **(Chroni c)**  Ca se 1 Ca se 2 Chroni c LOC=1.0**90**



### approached b y assuming equilibrium partitioning TM between the sediment and the pore water . Risk to benthic organisms was assessed using two approaches: (1) EECs for sediment were model - generated (PRZM/EXAMS) and compared to the toxicity value (NOAEC) as reported for sediment exposure in the sediment toxicity tests (normalized t o organic carbon) and (2) EECs for pore water were model - generated (PRZM/EXAMS) and compared to the toxicity value (NOA EC) as reported for pore water in the sediment toxicity tests. Results from the comparison of the maximum overall sediment EECs for TM to the various pore water NOAECs are shown in **Table 23**  . Comparison of pore water EECs and NOAECs indicate that pore water exposure to TM is three to four orders of magnitude below levels that affect growth, emergence and survival of benthic invertebrates . On the basis of sediment concentrations normalized to organic carbon, RQs are two to three orders of magnitude below adverse effect levels in freshwater and saltwater benthic invertebrates. **Table 23**  **. Subchronic and Chronic Risk Quotients for evaluating toxic risk of TM exposure to freshwater and estuarine/marine benthic invertebrates.**  **Organis m**  **NOAEC a,** 

**(μg a.i./kg OC)**  **NOAEC (μg**

**a.i./L pore wa**  **ter) Sediment** 

**EEC b**  **(μg a.i./ kg OC)**  **Pore Water**

**EEC (μg a.i./L pore**  **wa ter)**  **OC**  

** Normalized** **Sediment RQ**  **Pore water**

**RQ** FW Midge, C. riparius (28 - d) 7,700 13 418 0.061 0.05 0.005 SW Amphipod, L. plumulosus (10 - d) 81,000 380 0.061 0.005 0.0002

a Normalized to sediment organic carbon based on %TOC reported in the studies b Normalized to sediment organic carbon based on 4% default sediment TOC used in PR ZM/EXAMS



### c. **Aquatic Plants** Risk quotients for listed and non - listed aquatic plants were calculated for the modeled crop use with the highest estimated peak EECs (FL carrot for Case 1 and GA onion for Case 2; **Table 24**  ). No data were submitted on the effects of TM on other non - vascular plants ( e.g ., freshwater and saltwater diatoms, blue green algae) or aquatic vascular plants ( e.g ., duckweed) so RQs were n ot calculated for these taxa. For both Case 1 and Case 2, RQ values for both listed and non - listed aquatic non - vascular plants were orders of magnitude below the risk to listed and non - listed species LOCs.**91**

**Table 24**  **. Acute RQs**  **for non -**  **vascular aquatic plants exposed to TM.** Pla nt Type EC 50 (ug ai/L) a NOAEC

(ug ai/L) a Peak Water

Column EEC Non - Listed Species

RQ (EEC/EC 50 ) Listed Species RQ (EEC/NOAEC) Non - vascular plants (Case 1) 780 180 0.344 0.0004 0.002 Non - vascular plants (Case 2) 0.148 0.0002 0.0008 **a** For freshwater green algae ( Pseudokircheriella subcapitata ) the EC 50 = 780 ug a.i./L and NOAEC = 180 ug a.i./L (MRID 48737506) 

### 2. **Non -** **target Terrestrial Animals** As described in **Section III.B.3** , the T - REX model (v. 1.5, March 2012) was used in this assessment for estimating direct exposure of birds and mammals to TM via consumption of treated seeds. Exposure from the consumption of consumption of treated seed is calculated two way s: Exposure Method #1 is based on the TM concentration in seed (mg ai/kg seed) for comparing with acute and chronic dose - and dietary- based toxicity endpoints, and Exposure Method #2 is based on the mg ai/A for estimating LD 50 

### /ft2



### .

**a. Birds (Terrestrial Feeding)**  Using these two methods, acute RQs are calculated for different size classes of birds ( **Table 25**  ). None of the acute RQs exceed the risk to listed species LOC of 0.1, indicating a low potential for acute adverse effects to birds (a surrogate for terrestrial - phase amphibians and reptiles). Since all acute toxicity

endpoints for birds were non - definitive values, the lowest ac ute avian toxicity endpoint was selected for RQ derivation (14 - d LD 50 

### >2,000 mg ai/kg bw for the zebra finch). Therefore, a definitive acute RQ cannot be determined ; however, a non - definitive (“less than”) acute RQ can be determined which defines a value which the RQ is below. **Table 25**  **. Acute Avian RQs for Proposed TM Seed Treatment Uses Crop**  **Animal Size Avian Nagy Dose**  **(mg ai/kg -**  **bw/day) a**  **Adjusted LD 50** 

**(mg ai/kg**   ** bw****/day) b**  **Acute**

**Dose**   ** based RQ** **c Acute** 

**LD 50** **/** ft2 **d** Root Vegetables (CG1A) & Cotton **e** Small (20g) 124 2,159 <0.06 <0.01

Medium (100g) 70.4 2,749 <0.03 <0.01 Large (1000g) 31.5 3,883 <0.01 <0.01 All Other Crops **e** Small (20g) 24.7 2,159 <0.01 <0.01

Medium (100g) 14.1 2,749 <0.01 <0.01 Large (1000g) 6.30 3,883 <0.01 <0.01**92**

**Table 25**  **. Acute Avian RQs for Proposed TM Seed Treatment Uses Crop**  **Animal Size Avian Nagy Dose**  **(mg ai/kg -**  **bw/day) a**  **Adjusted LD 50** 

**(mg ai/kg**   ** bw****/day) b**  **Acute**

**Dose**   ** based RQ** **c Acute** 

**LD 50** **/** ft2 **d**

**a** based on maximum allowable seed treatment rate for TM ( **Table 18**  **) b**  Avian LD 50 values scaled according to body weight (unadjusted LD 50 > 2000 mg ai/kg bw based on finch; **Table 20**  ) **c** Acute RQ based on the ratio of the estimated dose to the body weight - adjusted LD 50 . **d** LD 50/f t2 based on maximum label application rate of 0.02 lb ai/A (=0.21 mg ai/ft2 ) divided by the body weight adjusted LD 50 values **e** See **Table 3**  for description of crop groups and seed treatment rates. Chronic risks to birds are estimated by comparing the allowable maximum seed treatment rates on the proposed TM label (488 mg ai/kg seed for Root Vegetables (CG1A) & Cotton and 97.7 mg ai/kg seed for all other uses) with the avian chronic NOAEC (500 mg ai/kg diet for mallard; MRID 40190202). The resulting chronic RQs are **0.98** and **0.20** respectively. For the higher allowable seed treatment rate for root vegetables and cotton, the predicted exposure is essentially equivalent to the chronic NOAEC resulting in a RQ of 1.0. 

### b. **Mammals (Terrestrial Feeding)** Using these two methods described previously for birds, acute RQs are calculated for different size classes of mammals ( **Table 26**  **)** . None of the acute RQs exceed the risk to listed species LOC of 0.1, indicating a low potential for acute adverse effe cts to mammals from direct consumption of TM - treated seeds. **Table 26**  **. Acute Mammalian RQs for Proposed TM Seed Treatment Uses Crop**  **Animal Size Mammalian Nagy**  **Dose (mg ai/kg**  **- bw/day)**  **a Adjusted LD**  **50**

**(mg ai/kg**   ** bw****/day) b**  **Acute**

**Dose**   ** based RQ** **c Acute** 

**LD 50** **/** ft2 **d** Root Vegetables (CG1A) & Cotton **e** Small (15g) 103 3,761 0.03 <0.01

Medium (35g) 71.4 3,043 0.02 <0.01 Large (1000g) 16.6 1,316 0.01 <0.01 All Other Crops **e** Small (15g) 20.7 3,761 0.01 <0.01

Medium (35g) 14.3 3,043 <0.01 <0.01 Large (1000g) 3.31 1,316 <0.01 <0.01 **a** based on maximum allowable seed treatment rate for TM ( **Table 18**  **) b**  Mammalian LD 50 values scaled according to body weight (unadjusted LD 50 =3500 mg ai/kg bw for mouse; **Table 20**  ) **c** Acute RQ based on the ratio of the estimated dose to the body weight adjusted LD 50 . **d** LD 50 /f t2 based on maximum label application rate of 0.02 lb ai/A (=0.21 mg ai/ft2) divided by the body weight adjusted LD 50 values **e** See **Table 3**  for description of crop groups and seed treatment rates. Chronic risks to mammals from consumption of seeds treated with TM are based on the body weight adjusted NOAEL of 12.2 mg ai/kg bw determined for the mouse compared to the estimated dose for**93**

different size classes ( 

### Table **27** ). Chronic RQs range from **0.72 to 7.9** , thus indicating a potential for chronic risks to mammalian wildlife consuming seeds treated with TM for all but the largest mammalian size class (1000g) with “other crops” using the lower seed treatment rate (97.7 mg ai/kg seed) . **Table 27**  **. Chronic Mammalian RQs for Proposed TM Seed Treatment Uses Crop**  **Animal Size Mammalian Nagy**  **Dose (mg ai/kg**  **- bw/day)**  **a Adjusted NOAEL** 

**(mg ai/kg -**  **bw/day) b**  **Chronic Dose**  

** based RQ** **c** Root Vegetables (CG1A) & Cotton **d** Small (15g) 103 13.1 **7.9**

Medium (35g) 71.4 10.6 **6.7** Large (1000g) 16.6 4.6 **3.6** All Other Crops **d** Small (15g) 20.7 13.1 **1.6**

Medium (35g) 14.3 10.6 **1.4** Large (1000g) 3.31 4.6 0.72 **a** Based on maximum allowable seed treatment rate for TM ( **Table 18**  **) b**  Mammalian NOAEL values scaled according to body weight (unadjusted NOAEL =12.2 mg ai/kg bw for mouse; **Table 20**  ) . **c** Chronic RQ based on the ratio of the estimated dose to the body weight - adjusted LD 50 . **d** See **Table 3**  for description of crop groups and seed treatment rates. RQ values in bold indicate exceed the chronic risk LOC of 1.0.



### 3. **Piscivorous Birds and Mammals** As discussed in the Section III, TM is hydrophobic with a measured log Kow 

### of 3.8. Therefore, the potential exists for TM and its bound residues to bioaccumulate in aquatic organisms that serve as dietary

sources for terrestrial wildlife. In this section, risks to piscivorous birds and mamm als are described that result from consumption of aquatic prey that have been predicted to bioaccumulate TM and its associated degradates of concern.

**a. Predicted Residues in Fish**  Two approaches were used to predict residues of TM in aquatic organisms. Th e first approach relied on the KABAM model (v. 1.0) which uses a food web bioaccumulation model to estimate chemical concentrations in tissues of aquatic organisms. The technical basis and parameterization of this model is summarized in USEPA 2009 12 

### . The primary chemical - specific inputs to the KABAM model are K ow 

### , K oc 

### , surface water EEC, and pore water EEC. Since the expected time to steady

state in fish tissue is short ( < 0.5 day s based on bioconcentration studies) , peak EECs were used as input to KABAM. Peak surface water and pore water EECs ( 0.34 and 0.07 ug ai/L , respectively) were obtained from Florida Carrot scenario ( **Table 15**  ) which produced the highest surface water EECs.

12 Available at: http://www.epa.gov/oppefed1/models/water/#KABAM**94**



### The second approach used to predict TM in aquatic organisms involved the use of the measured bioconcentration factor (BCF). Specificall y, a whole - fish BCF of 506 L/kg wet wt was used in conjunction with the maximum peak EEC in surface water (0.34 ug ai/L) to estimate TM in fish tissue. This whole body

fish BCF represents concentrations of parent TM and any degradate that formed during the expo sure portion of the BCF study . Predicted residues in aquatic organisms using both approaches (KABAM and measured BCF) are provided in **Table 28**  . N otably , KABAM estimates similar BCF values as that measured for TM (200 - 300 vs. 506 L/kg wet wt. ) and as a result, predicted concentrations in fish tissue are similar. This finding provides evidence that the assumptions used in the KABAM modeling (no biotransformation) are reasonable. It is also worthy to note that KABAM includes uptake from the aquatic diet as well as through respiration, while the measured BCF includes uptake only through respiration. For chemicals with log Kow 

### <4, dietary uptake is no t predicted to be a significant route of exposure to top trophic level fish. Again, the similarity in KABAM predicted BCFs to the measured BCF supports the conclusion that dietary uptake is not an important route of exposure to fish. **Table 28**  **. Predicted residues of TM in aquatic organisms using KABAM and BCF Methods.**  **Peak EECs in surface water (pore water); ug** 

**ai/L Organism Type**  **(% lipid) Predicted TM in** 

**Tissue (ug ai/kg ww)**  **Predicted BCF**

**(measured BCF) (L/kg ww)**  **KABAM -**  **Based Modeling Method**

0.34 (0.07) Phy toplankton (2%) 100 304 Zooplankton (3%) 74 217 Benthic Invertebrates (3%) 77 226 Filter Feeders (2%) 51 149 Small Fish (4%) 100 290 Medium Fish (4%) 101 290 Large Fish (4%) 108 304 **BCF -**  **Based Modeling Method** 

0.34 Fish (~4%) 174 ( 506 ) 

### Based on the predicted residues in aquatic organisms, feeding and respiration rates for aquatic organisms, and toxicity

values for birds and mammals, risks to piscivorous wildlife were calculated **( Table**  **29 ).**  Not surprisingl y given the low aquatic EECs and low toxicity of TM to terrestrial wildlife, acute and chronic RQ values are well below level s of concern.

**Table 29**  **. Calculation of RQ values for mammals and birds consuming fish contaminated by 95** 

**Tolclofos Methyl. Wildlife Species**  **Acute RQs*** **Chronic RQs 

** Dose Based** **Dietary**

**Based Dose Based**  **Dietary Based Mam**  **malian** fog/water shrew 0.000 N/A 0.004 0.001 rice rat/star - nosed mole 0.000 N/A 0.005 0.001 small mink 0.000 N/A 0.006 0.001 large mink 0.000 N/A 0.007 0.001 small river otter 0.000 N/A 0.008 0.001 large river otter 0.000 N/A 0.009 0.001 **Avian** sandpipers 0.000 0.000 N/A 0.000 cranes 0.000 0.000 N/A 0.000 rails 0.000 0.000 N/A 0.000 herons 0.000 0.000 N/A 0.000 small osprey 0.000 0.000 N/A 0.000 white pelican 0.000 0.000 N/A 0.000 * based on acute LD 50 values of >2000 mg ai/kg bw for birds (zebra finch) and 3500 mg ai/kg bw for mammals (mouse) ** based on chronic NOAEC of 500 ppm in diet for birds (mallard) and 100 ppm for mammals (mouse)



### 4. **Non -** **target Beneficial Insects** The Agency

does not currently

conduct quantitative risk assessments for non - target beneficial insects ( e.g ., honey

bee). Rather, the potential exposure of honey bees to pesticides is assessed qualitatively

based on laboratory

data and if available, field data. For the proposed seed treatment uses of TM, the usu al routes of exposure such as spray drift are not applicable. Furthermore, TM is considered a non - systemic fungicide thus reducing potential exposure via transport within the plant to pollen and nectar. However, there is evidence of potential exposure to other pesticides used for seed treatment via drift of dust from abraded treated seed coat (Krupke et al . 2012). Conceptuall y, this route of exposure may also exist for TM; however, no information specific to TM or this proposed use is available to quanti fy this exposure route. It is also noted that TM is classified as practically non - toxic to young adult honey bees (acute contact LD 50 

### >100 ug ai/bee) and has a very low application rate (0.02 lb ai/A). Therefore, while conceptuall y a potential route of exposure of TM - treated seeds exists for honey bees and other insect pollinators, the very low toxicity

of TM to honey

bee and its low application rate suggest that this route of exposure is not likely to be a concern. **5. Non**  **- target Terrestrial Plants** **96**



### No data were submitted on the effects of TM on non - target terrestrial plants. Therefore, RQs were not derived and risks to terrestrial plants could not be quantified. As discussed above with honey bee, spray

drift and runoff are not considered dominant routes of exposure of TM to terrestrial plants. However, there is a potential for exposure of terrestrial plants adjacent to treated fields via drift of abraded seed coating dust. Additional discussion of the potential risks of TM is provided in **Section IV.B (Risk Description)**  . **B. Risk Description**  **- Interpretation of Direct Effects**  In risk description, the results from the risk estimation are interpreted and sy nthesized into overall risk conclusions. When available, other lines of evidence are considered for characterizing ecological risk ( e.g ., monitoring data, ecological incident reports, refined exposure and effects modeling, data for structurally similar pesticides, etc .). In the case of TM, no information is available on monitored concentrations in the environment or ecological incident reports because it is a new pesticide. The risk description also contains a discussion of relevant sources of uncertainty in the risk assessment and s ensitivity of the risk assessment findings to important methodological assumptions. Those uncertainties that are specific to certain taxonomic groups are discussed in the following sections. Those uncertainties that are generic to this assessment ( i.e ., extending across taxonomic groups) are described in **Section IV.C** .

**1. Risks to Aquatic Animals** 

**a. Potential for Acutely Toxic Exposures**  Fish and Aquatic Invertebrates The previous risk estimation section indicates a low potential for acutel y toxic exposures to aquatic animals from the proposed seed treatment uses of TM. Even with the most conservative exposure assumptions considered (Case 1), acute RQs calculated for fish and aquatic invertebrates are at least two orders of magnitude below the LOC for listed species (0.05 ) and three orders of magnitude below the LOC for non - listed species (0.5; **Table 21**  **, Table**  **22** , Figure 9 

### , **Figure 11**  

### ). This low potential for acute effects to aquatic animals is determined by the limited exposure to aquatic sy stems (low application rate of 0.02 lb ai/A and soil incorporation of treated seeds) and low acute toxicity of TM to aquatic animals. Regarding the latter, available data indicate TM is acutel y toxic to aquatic animals ne ar its reported solubility in water (700 ug ai/L) which is much greater than the maximum EEC predicted in surface water (0.344 ug ai/L). Itis further noted that the difference in acute RQs derived using the two exposure methods (Case 1 and Case 2) was re latively minor (about a factor of two) and therefore, does not impact these risk assessment conclusions. Available information also indicates the major degradate (DM - TM) is practicall y non - toxic to D. magna and rainbow trout, thus supporting the exclusion of this degradate from the aquatic EECs ( **Error! Reference source not found.** 

### Table **19** ).**97**



### Itis noted here that the EC 50 

### reported for D. magna (2.4 mg ai/L ; MRID 00156120) is well above the reported solubility in water (0.7 mg ai/L). Although a co - solvent was used in this study and no precipitates were reported, it is not clear that observations of precipitates were made, and other similar studies reported precipitation problems with multiple co - solvents as concentrations approach the solubility limit. Th erefore, because of the uncertainty regarding the actual bioavailability of TM in the Daphnia study , the EC 50 

### was assumed to be at the limit of water solubility

( 0.7 mg ai/L) . This assumption did not alter the risk conclusions in relation to the reported EC50 of 2.4 mg ai/L. **b. Potential for Chronically Toxic Exposures**  Aquatic Invertebrates (Water Column) Available data also suggest a low potential for chronic toxicity to aquatic invertebrates (water column dwelling) with maximum chronic RQ values ranging from **0.004 to 0.05** , depending on exposure assessment method and taxonomic group ( **Table 22**  **).** Aquatic Invertebrates (Benthic) For benthic - dwelling invertebrates, subchronic (10 - d) and chronic RQs range from **0.0007 to 0.005**  (pore water basis). Although uncertainties were identified in two of the three submitted benthic invertebrate toxicity studies, these uncertainties are not likel y to affect the risk assessment conclusions regarding benthic invertebrates. Specifically , the NOAEC of 0.013 mg ai/L - pore water derived for the freshwater midge (MRID 48737504) reflects a spiked overl yi ng water design with no equilibration prior to testing. As a result, overl yi ng water concentrations declined as TF partitioned to sediments; sediment concentrations increased substantially during the first two weeks of the test. Although this test design is in accordance with OECD Guideline #219, OSCPP draft guidelines recommend spiked sediment with equilibration prior to testing. Furthermore, the OECD Guideline #219 is inten ded to simulate a single spray drift event, whereas TM is expected to be transported to water primarily via erosion of TM - sorbed sediment. The NOAEC of 0.38 mg ai/L - pore water derived from the toxicity study with the saltwater amphipod, L. plumulosus , ref lects a combination of dose response information from two separate experiments ( **see Section III.C** ) because the first experiment resulted in adverse effects at all treatment levels. Neither experiment determined a NOAEC that was bounded by a LOAEC, but in combination, a definitive NOAEC of 0.38 mg ai/L - pore water could be estimated. Therefore, this NOAEC is subject to uncertainty associated with using dose - response information from separate batches of organisms over different times. Despite the aforementi oned uncertainties in the submitted sediment toxicity studies, the maximum pore water EEC (0.06 ug ai/L) is still several orders of magnitude below the available NOAECs (13 - 854 ug ai/L - pore water). Thus, these uncertainties are not likely to alter the c onclusion of low potential risk to benthic invertebrates.**98**



### Fish Qualitatively , the likelihood of chronic effects to fish also appears to be low with the proposed seed treatment uses of TM ( **Table 21**  ). However, limitations in the available chronic toxicity data introduce some uncertainty in this risk conclusion. Specifically , no chronic data are available for saltwater fish and the only available study for freshwater fish (rainbow trout) resulted in a non - definitive NOAEC of <12 ug ai/L (MRID 42106501). For bounding purposes, the L OAEC of 12 ug ai/L (14% reduction in fry weight) was used to calculate a chronic RQ based on a maximum 1 in 10 year 60 - d av erage EEC of 0.147 ug ai/L( **Table 21**  ). This calculation resulted in a chronic RQ of >0.01 using the maximum EEC derived for Case 1 and >0.005 for the maximum EEC derived using Case 2. The “>” sign is used to distinguish these RQs because the actual NOAEC is known to be below 12 ug ai/L . Obviously , such unbounded RQs do not enable a conclusive determination of risk (or lack thereof) to be made. Howev er, in order for the chronic risk L OC to be exceeded for freshwater fish, the NOAEC would have to be about 0.15 ug ai/Lwhich is about 100X below the L OAEC of 12 ug ai/L. For several reasons, this occurrence is considered highl y unlikely. First, the origi nal NOAEC derived from this study was 12 ug ai/L based on comparison to the solvent controls. However, according to current EFED policy , comparisons should be made to negative controls which resulted in a NOAEC of <12 ug ai/L . Since no significant diffe rence was detected between the solvent and negative controls, it is evident that the statistical determination of the NOAEC is sensitive to the ty pe of controls used for comparison and their associated variance. Second, the biological responses associated with the LOAEC (14% reduction in fry weight 60d post - hatch; 4% reduction in fry length, 37d post - hatch) are considered relativel y modest from a biological perspective. Fry lethality occurred at much higher concentrations ( > 110 ug ai/L) and reductions in e gg hatching occurred at 200 ug ai/L. Therefore, this dose - response pattern is not suggestive of a NOAEC that would be two orders of magnitude below the current LOAEC of 12 ug ai/L . Rather, it is suggestive of a NOAEC that would be one or two dose levels below the current LOAEC. No data are available on the effect of chronic exposures of saltwater fish to TM. However, the available toxicity

data do not suggest that saltwater fish are any more sensitive compared to freshwater fish ( **Error! Reference so urce not found.**  

### Table **19 ).**  Specificall y, The acute LC 50 

### for saltwater fish (0.372 mg ai/Lfor sheepshead minnow) is similar to the range of L C 50 

### values for freshwater fish (0.69 to 3.2 mg ai/L). Furthermore, given the low aquatic EECs associated with the proposed seed treatment uses of TM, the chronic NOAEC for saltwater fish would have to be 100X lower than the current L OAEC for freshwater fish (12 ug ai/L). Although theoreticall y possible, the available data suggest that it is unlikely for saltwater fish to be so much more chronicall y sensitive to TM to warrant chronic risk concerns, hence, the requirement for chronic toxicity data for saltwater fish was recentl y wai ved for the proposed seed treatment uses (D393184). Aquatic Plants Based on the only

available data for green algae (P. subcapitata) , risk quotients are 1000X below aquatic plant risk LOCs (1.0) for the modeled crop use with the highest estimated exposure values (FL carrot for Case 1 and GA onion for Case 2; **Table 24**  ). However, no data were**99**



### available for other taxa of non - vascular aquatic plants (diatoms, blue - green algae) or vascular aquatic plants, thereb y introducing uncertainty in the risk conclusions for aquatic plants. In order to characterize the uncertainty associated with the lack of toxicity data for aquatic plants, relevant toxicity

endpoints for aquatic plants tested with other phosphorothionate organophosphate pesticides were evaluated. The phosphorothionate class of OP pesticides was chosen since it has the potential t o form oxon degradates of greater toxicity , similar to TM. Available data in OPP/EFED’s Ecotoxicity database were identified, screened for acceptable or supplemental studies. The vast majority data were non - definitive (“>”) values, indicating overall low phy totoxicity as would be expected given the MOA of OP insecticides. Among these data, the most sensitive, definitive toxicity values were selected for a given chemical/species combination ( **Table 30**  

### ). Data on aquatic plants were limited for this type of OP pesticides. However, the maximum peak aquatic EEC for TM (0.344 ug ai/L) is still three orders of magnitude below the most sensitive EC 50 

### (140 ug ai/Lfor bensulide) and two orders of magnitude below the most sensitive NOAEC (42 ug ai/L for bensulide). Although not conclusive, this comparison , combined with the mode of action of TM, suggests that the proposed seed treatment uses of TM have a low pot ential to result in risk concerns for aquatic plants. **Table 30**  **. Aquatic Plant Toxicity Data Obtained For Other Phosphorothionate**  **Organophosphate Pesticides**  **Chemical Species**  **EC 50**  **(m g ai/L)**  **NOAEC**

**(m g ai/L)**  **MRID** Bensulide Duckweed

( Lemna gibba) 0.14 0.042 44720406 Dimethoate Green Algae (P.

subcapitata ) 110 19.7 47784001 Methyl parathion Marine diatom

(Skeletonema costatum) 5.3 N.R. 40228401 Phorate Marine diatom

(S. costatum) 1.3 N.R. 40228401 Diazinon Green Algae (P.

subcapitata ) 3.7 N.R. 40509806 Chlorpyrifos Marine algae

( Isochrysis galbana ) 0.14 N.R. 40228401 Source: USEPA EFED Ecotoxicity Database (accessed 9 - 23 - 3011)



### 2. **Risks to Terrestrial Animals**

**a. Potential for Acutely Toxic Exposures**  Birds and Mammals Acute risk to birds are considered low as indicated by acute RQs of <0.01 to <0.06 ( **Table 25**  ) which are all below the acute risk LOC for listed species (0.1). These RQ values are based on**100**



### the most sensitive LD 50 

### value available (LD 50 

### >2,000 mg ai/kg bw for zebra finch; **Table 20**  **)** . Only upper bound (non - definitive) RQs could be determined because no treatment related mortality occurred at the highest dose tested in the available toxicity studies ( i.e ., non - definitive LD 50 

### values). A review of these studies for sublethal effects also indicates no treatment - related effects on endpoints such as food consumption, body weight and behavior. Similar to birds, acute risks to m ammals are considered low as indicated b y acute RQs of <0.01 to 0.03 ( **Table 26**  ). These RQ values are based the most sensitive acute toxicity endpoint available (LD 50 

### =3,500 mg ai/kg bw for mouse; **Table 20**  ). Clinical signs of toxicity occurred at >1,500 mg ai/kg bw for mouse and included ataxia, irregular respiration, decreased motor activity . Clinical signs of toxicity in rats occurred at > 3,500 mg ai/kg bw. These levels are all an order of magnitude or more above the estimated ingested dose associated with the proposed TM uses (3.3 - 103 mg ai/kg b w). Risk estimation also indicates that piscivorous birds and mammals are not likel y to encounter acutel y toxic exposures to TM ( **Table 29**  ). **b. Potential for Chronically Toxic Exposures**  Birds Chronic dietary- based RQs for birds (0.20 - 0.98; Section IV.A.2) indicate chronicall y toxic exposure to TM treated seeds may be approached with the proposed uses on root vegetables and cotton, where the highest seed treatment rate is used. These chronic RQs are based on a dietary NOAEL of 500 ppm for mallard duck (MRID 40190202) based on reproductive effects (reductions in # eggs set, viable embryos, hatching success) which occurred at the LOAEL of 2,500 pp m in the diet. Very similar results were obtained from a chronic study with bobwhite quail in terms of the NOAEL(500 ppm) and LOAEL(2,500 ppm). The wide dose spacing used in these two studies (a factor of 5 between the NOAELand LOAEL) introduces some uncertainty as to the potential for chronic toxicity to birds with an effective chronic RQ of 1.0. It is also noted that the potential for chronic risks to birds is also sensitive to the assumption that the avian diet is comprised of 100% of seeds treated with TM (488 mg ai/kg seed). Some factors that would likely

lead to lower chronic risks include the soil incorporation of TM treated seeds (broadcast applications are not allowable) and the availability of alternative forage items . Furthermore, any addit ional exposure of birds to TM via abraded seed coating dust would also increase the potential for chronic risks. Risk estimation also indicates that piscivorous birds are not likel y to encounter chronically toxic exposures to TM ( **Table 29**  ). Mammals Chronic risks associated with mammalian consumption of TM treated seeds are indicated in this assessment, with chronic RQs ranging from **0.7 to 7.9** ; **Table 27**  ). Chronic risks are identified for all size classes of mammals considered (15, 35 and 1000g) with the highest TM seed treatment**101**



### rate for root v egetables and cotton (488 mg ai/kg seed). With the lower seed treatment rate (97.7 mg ai/kg seed), chronic risk concerns are identified for the small and medium size mammals, but not large (1000 g) mammals. These RQ values are based on a NOAEL of 100 ppm in the diet (12.2 mg ai/kg bw) identified for mouse (MRID 00156137). The LOAEL from this study was 3000 ppm in the diet (503 mg ai/kg bw) based on reduced body weighs of males and females. A reduction in plasma cholinesterase was also observed at 30 ppm fo r female mice. As with the chronic avian toxicity

study , the wide dose spacing between the NOAEL (100 ppm) and LOAEL (3000 ppm) introduces uncertainty in the risk assessment conclusions because the actual NOAEL may be any where between 100 and 3000 ppm and narrower dose spacing been used . For other mammalian taxa (rat, dog), developmental and subchronic NOAELs are 300 and 600 ppm respectivel y, suggesting that the potential exists for chronic risk to other mammalian taxa as well. As noted with the chronic avian risk characterization, the incorporation of TM - treated seeds in soil as required by the label would lead to reductions in chronic risks to mammals, particularl y for crops with deeper minimum planting depths ( e.g ., corn at 3.8 cm; **Table 3**  **)** . Risk estimation also indicates that piscivorous mammals are not likely to encounter chronicall y toxic exposures to TM ( **Table 29**  ). Non - target Beneficial Insects Current data suggest a low potential for adverse effects of the proposed seed treatment uses of TM to honey

bees. This low risk potential is based on the lack of spray drift from the proposed uses (seed treatment) and low acute toxicity to young adult bees ( LD 50 

### >100 ug ai/bee). Furthermore, TM is considered a non - systemic fungicide thus reducing potential exposure via transport within the plant to pollen and nectar. Although the conceptual model identified the potential for off

- site transport of abraded seed coat dust during planting of TM - treated seeds, the very low application rate (0.02 lb ai/A) in relation to its low acute toxicity sugges t this route of exposure is not likely

to be a concern. **3. Risks to Terrestrial Plants**  No data were submitted on the effects of TM on non - target terrestrial plants. Therefore, RQs were not derived and ris ks to terrestrial plants could not be quantified. As discussed above with honey bees, spray

drift and runoff are not considered dominant routes of exposure of TM to terrestrial plants. There is potential, however, for exposure of terrestrial plants adjacent to treated fields via drift of abraded seed coating dust. In an effort to characterize the uncertainty associated with the lack of toxicity data for terrestrial plants and its effect on the risk conclusions, terrestrial plant toxicity data for other ph osphorothionate OP pesticides were reviewed. The phosphorothionate class of OP pesticides was chosen since it has the potential to form oxon degradates of greater toxicity , similar to TM. Of the 92 terrestrial plant EC 25 

### values reported for acceptable or supplemental studies in the EFED Ecotoxicity

database, only

25 were definitive values for three pesticide active ingredients (four formulations). Nearly all the remaining were “>” values indicating less than 25% effect at**102**



### the highest treatment tested, su ggesting that this class of pesticides is not readily toxic to terrestrial plants at labeled application rates. The most sensitive definitive EC 25 

### and NOAEL values from the aforementioned OP plant toxicity studies are summarized below in **Table 31**  

### . Assuming that TM acts similarly on terrestrial plants as these other OP pesticides, it appears that its proposed use for seed treatment would have a low potential for risk to terrestrial plants, even if plants were exposed at maximum labeled application rate (0.02 lb ai/A). In other words, TM would have to be about 50 times more toxic than the most toxic OP for which we have data in order for risks concerns to non listed terrestrial plants to be realized. For listed terrestrial plant species, TM would have to be 20 times more toxic than the most toxic OP for which we currentl y have data in order for risk concerns to be identified. **Table 31**  **. Terrestrial Plant Toxicity Data Obtained For Other Phosphorothionate**  **Organophosphate Pesticides Chemical**  **Species EC25**  **(lb ai/A) NOAEL** 

**(lb ai/A) MRID**  Bensulide Cucumber

( Cucumis sativus) 1.3 0.38 44746301 (v.v.) Dimethoate (400 Form ulation) Tomato

(Lycopersicon esculentum) 0.91 0.91 47709702 (s.e.) Dimethoate Corn

(Zea mays) 0.98 0.98 47709702 (s.e.) Diazinon Cucumber

( Cucumis sativus) 3.2 3.2 40803002 (s.e.) Source: USEPA EFED Ecotoxicity Database (accessed 9 - 23 - 3011) ; v.v.=vegetative vigor study; s.e. = seeding emergence study.



### 4. **Review of Incident Data** Because TM has not been previously a pproved for use in the United States, there are no incident reports for this chemical.

**5. Threatened and Endangered Species Concerns**  For listed species assessment purposes, the action area is considered to be the area affected directly or indirec tly

by the Federal action and not merel y the immediate area involved in the action. At the initial screening - level, the risk assessment considers broadl y described taxonomic groups and so conservatively assumes that list species within those broad groups are collocated within the pesticide treatment area. This means that terrestrial plants and wildlife are assumed to be 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 which has the relativel y highest potential exposure to the pesticide, and that exposures are likely to decrease with distance from the treated area. If the assumptions associated with the screening - level action area result in RQs that are below**103**



### the listed species LOCs, “no effect,” determination conclusion may be made with respect to listed species in that taxa (for direct effects), and no further refinement of the action 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 as a resource. However, in situations where the screening assumptions lead to RQs in excess of the risk to listed species LOCs for a given taxonomic group, a potential “may affect,” conclusion exists and may

be associated with direct effects on listed species belonging to that taxonomic group or may

extend to in direct effects upon listed species that depend on that taxonomic group as a resource. In such cases, additional information on the biology of the listed species, the locations of these species, and the locations of use sites could be considered along with available information on the fate and transport properties of the pesticide 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 i nformation 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. In conducting a screen for indirect effects, direct effects LOCs for each taxonomic group are used to make inferences concerning the potential for indirect effects upon listed species that rel y upon non - listed organisms in these taxonomic groups as resources critical to their cycle. Pesticide use scenarios resulting in RQs that are below all direct effect listed species LOCs for all taxonomic groups assessed are considered of no concern for risks to listed species either b y direct or indirect effects. For TM, the potential direct effects to listed species should they co - occur w ith application sites are indicated for mammals (chronic toxicity) and birds (including terrestrial - phased amphibians and reptiles; chronic toxicity) based on consumption of treated seeds. Risk to listed species LOCs are not exceeded for any other taxonom ic group assessed (aquatic animals, aquatic plants, non - target invertebrates). For the maximum proposed TM application rates, there may be a potential concern for direct effects to the following groups of organisms:

• Birds • Mammals • Terrestrial - phase reptiles • Terrestrial - phase amphibians A spatial co - occurrence analy sis would be necessary to delineate the action area. **C. Description of Assumptions, Limitations, Uncertainties, Strengths and Data**  **Gaps 1.**  **Exposure for All Taxa 104** 



### There are a number of areas of uncertainty in the aquatic and ter restrial risk assessments. The toxicity assessment for terrestrial and aquatic plants and animals is limited by the number of species tested in the available toxicity studies. Use of toxicity

data on representative species does not provide information on the potential variability in susceptibility among species to acute and chronic exposures. For each proposed use, the risk assessment is based on the maximum application rate on the proposed label. The frequency at which actual uses approach these maximum scenarios is dependent on the resistance to the pesticide, the timing of applications, and market forces. Exposure and risks could be overestimated if the actual application rates, frequency of application, or number of applications are lower than the in put parameters used for the conservative exposure scenario that was modeled. .

**2. Exposure for Aquatic Species**  This Tier II risk a ssessment relies on best available estimates of environmental fate and phy sicochemical properties, maximum application rate of TM, minimum planting depth of seeds, and maximum seeding rates. However, several uncertainties and model limitations are noted a nd should be considered in interpreting the results of this aquatic risk assessment.

• The frequency

at which actual TM uses approach the use estimates modeled is dependent on resistance to the insecticide, timing of applications, and market forces. In general, model output values represent the upper - bound estimates of concentrations that might be observed in surface water due to the application of TM, given available data and model limitations.

• Although there are uncertainties associated with using the standard PRZM/EXAMS runoff scenario (10 - ha field draining into 20,000 m 3 

### pond with no outlet) for an aquatic exposure assessment, it is designed to represent pesticide exposure from an agricultural watershed impacting a vulnerable aquatic environment. Extrapolating the risk conclusions from this standard pond scenario may either underestimate or overestimate the potential risks.

• Major uncertainties associated with the standard runoff scenario include the phy sical construct of the watershed and repr esentation of vulnerable aquatic environments for different geographic regions. The phy sicochemical properties (pH, redox conditions, etc.) of the standard farm pond are based on a Georgia farm pond. These properties are likely to be regionally

specific because of local h ydrogeological conditions. Any alteration in water quality parameters may impact the environmental behavior of a pesticide. The farm pond represents a well mixed, static water body. Because the farm pond is a static water body (no flow through), it does not account for pesticide removal through flow through or water releases. The lack of flow through the farm pond provides an environmental condition for accumulation of persistent pesticides. The assumption of uniform mixing does not a ccount for stratification due to thermoclines ( e.g. , seasonal stratification in deep water bodies). Additionall y, the dimensions of the standard runoff**105**



### scenario assume a watershed area to water body volume ratio of 10 ha: 20,000m 3 

### . This ratio is recommen ded to maintain a sustainable constructed pond in the Southeastern United States. The use of higher watershed area to water body volume ratios (as recommended for sustainable ponds in drier regions of the United States) may lead to higher pesticide concentrations when compared to the standard watershed area to water body volume ratio.

• The standard runoff scenario assumes uniform soils and agronomic management practices across the standard 10 - hectare field. Soils can vary substantiall y across even small areas; this variation is not reflected in the model simulations. Additionally , the impact of unique soil characteristics and soil management practices ( e.g. , tile drainage) are not considered in the standard runoff scenario. The assumption of uniform si te and management conditions is not expected to represent some site - specific conditions. Extrapolating the risk conclusions from the standard pond scenario to other aquatic habitats ( e.g. , marshes, streams, creeks, and shallow rivers, intermittent aquatic areas) may either underestimate or overestimate the potential risks in those habitats.

• For an acute risk assessment, there is onl y a one - day averaging time for exposure. Use of such a “peak” concentration, with a 1 - in - 10 year annual return frequency , implies that exposure is sufficient to elicit acute effects comparable to those observed over more protracted exposure periods tested in the laboratory, typicall y 48 to 96 hours. In the absence of data regarding time - to - toxic event analy ses and lat ent responses to peak exposure, the degree to which risk is overestimated cannot be quantified.

**3. Exposure for Terrestrial Species**  This risk assessment relies on the best available estimates of environmental fate and phy sicochemical properties, maximum application rate of TM, maximum number of applications, and the shortest interval between applications. However, several uncertainties and model limitations are noted and should be considered in interpreting the results of this terrestrial risk assessment.

**a. Location of Wildlife Species**  For screening terrestrial risk assessments, a generic bird or mammal is assumed to consume 100% of its diet as treated seeds from the application site. This assumption may lead to an overestimation of exposure to species that do not occup y the treated fie ld. The actual habitat requirements of any particular terrestrial species are not considered, and it is assumed that species occup y, exclusively and permanently, the treated area being modeled. This assumption leads to a maximum level of exposure in the risk assessment. **b. Routes of Exposure** **106**



### Dietary Exposure Screening - level risk assessments for spray applications of pesticides assume that 100% of the diet is relegated to single food ty pes foraged onl y from treated fiel ds. These assumptions are likely to be conservative for many species and will tend to overestimate potential risks when species are foraging on multiple sources of food (i.e., not just treated seeds) . Specific to the proposed seed treatment use of TM, the terrestrial exposure modeling did not account for the required soil incorporation of seeds (broadcast application is prohibited by the label). Therefore, exposure is likely

to be overestimated especiall y for seeds with greater planting depths. Furthermore, while the assumption of 100% diet from a treated area may be reasonable worst case assumption for acute exposures, this assumption is likely much less applicable to long - term (chronic) exposures modeled as single food types composed entirel y of treated se eds. Data on the amount of wildlife diet composed of seeds from treated fields would be needed to reduced this uncertainty. **Dermal Exposure** The screening assessment does not consider TM dermal exposure to terrestrial organisms. The Agency

is activel y pursuing modeling techniques to account for dermal exposure via direct application of spray

and by incidental contact with contaminated vegetation, soil and water. **Drinking Water Exposure** Drinking water exposure to a pesticide active ingredient may be the result of consumption of surface water or consumption of the pesticide in dew or other water on the surfaces of treated vegetation. For pesticide active ingredients with a potential to dissolve in runoff, puddles on the treated field may

contain the ch emical. The SIP tool (version 1.0) was used to assess the potential for exposure concerns to birds and mammals via drinking water alone. TM’s solubility in water (0.7 mg/L) and toxicity to avian and mammalian species are inputs for the potential upper - boun d drinking water calculations. Because no definitive endpoints were available for acute oral avian studies, the highest concentration tested was used as an upper - bound estimate of acute toxicity

(2000 mg a.i./kg bw for birds). For mammals, an LD 50 

### of 3,500 mg/kg bw was used (mouse) which was the lowest acceptable LD 50 

### value identified. Chronic NOAEL/NOAEC toxicity values used for birds and mammals are 500 ppm (mallard) and 12.2 mg/kg bw (mouse). Based on this information, TM exposure through drinking water alone does not present an acute or chronic exposure route of concern for mammals or birds.

**c. Incidental Pesticide Releases Associated with Use**  This risk assessment is based on the assumption that the entire treatment area is subject to TM application at the rates specified on the label. This translates to an even seeding rate across an entire field. In reality, there is the potential for uneven application of TM through such plausible incidents as changes in calibration of application equipment, spillage, and localized releases at**107**



### specific areas of the treated field that are associated with specifics of the type of application equipment. **4. Effects Assessment**  The data available to support the terrestrial and aquatic effects assessment for TM is incomplete. Data gaps, uncertainties and limitations are summarized as follows:

 Chronic effects to estuarine/marine fish and estuarine/marine invertebrates : No chronic data were submitted for estuarine/marine fish or estuarine/marine invertebrates. An acute to - chronic ratio could not be calculated due to lack of available data on definitive chronic toxicity endpoints for freshwater fish. The expected chron ic exposure of TM to aquatic organisms is low (maximum 60 - day EEC = 0.147 μg a.i./L). The LOAEC associated with the freshwater chronic study is 12 ug ai/L and reflects a 14% reduction in body weight relative to negative controls. As described in **Section I V.B**  , the NOAEC for saltwater fish would have to be nearly 100X lower than the L OAEC for freshwater fish in order for chronic risk concerns to be identified. Given that acute toxicity of freshwater and saltwater fish appear similar (albeit based on a limit ed data set), there is currently no evidence to suggest that saltwater fish would be more sensitive than freshwater fish b y this magnitude. Based on these lines of evidence, chronic testing with estuarine/marine fish or estuarine/marine invertebrates is n ot requested at this time.  Solubility in aquatic tests : According to the submitted fate information, TM is characterized b y a water solubility ranging from 0.7 to 1.0 mg a.i./L. In several acute toxicity studies with aquatic organisms, solubility problem s were either noted or suspected (see **Section III.B** ) even with the use of co - solvents. Although the bioavailability

of TM in these studies is in question when samples were not centrifuged and/or filtered prior to analy sis, the extremel y low aquatic EECs (maximum peek = 0.344 ug ai/L) render this uncertainty less likel y to affect the risk conclusions.

 Aquatic /Terrestrial plant toxicity studies : Toxicity data were available for only 1 aquatic non - vascular plant (green algae) and no vascular aquatic plant s. No toxicity data were submitted for terrestrial plants either. Based on an anal ys is of other OP pesticides in a similar class ( Phosphorothionate ), the need for additional data for plants was considered not likely to materiall y affect the risk assessment conclusions.

 Oxons: Under biologically mediated degradation, oxons of TM (e.g., TMO and DM TMO) may

be formed in minor amounts (< 10%). Such oxons have the potential to be substantially

more toxic than the parent compounds. However, no data were available on the toxicity

of these oxons. A bounding anal ys is was conducted to exposure the importance of oxon data for the proposed TM u ses. Specificall y, it was assumed that the TM aquatic EECs contain 10% oxons and that their toxicity is 100X greater than that of parent TM (the maximum toxicity difference observed in other oxon studies 13 

### ) . For risks 13 Guidance for Registration Review Data Requests for Oxon Degradates of Organophosphate Insecticides (OP). Memo from Don Brady (Division D irector). March 10, 2009

### 108

to aquatic organisms, the taxon/effec t with the least least difference between the RQ and LOC is chronic risk to saltwater invertebrates; RQ =0.05, LOC=1). If one assumes the maximum 21 - d chronic EEC (0.149 ug ai/L) is comprised of 10% oxon (0.0149 ppb) and that the oxon is 100X more toxic than the saltwater invertebrate toxicity reference value ( i.e., 0.0 39 ppb based on my sid NOAEC of 3.9 ppb ), the combined RQ of the parent and oxon would still be 0.4 (0.03 for parent, 0. 38 for oxon) which is still less than the chronic LOC of 1. For terres trial risk assessment, data on the metabolism of TM by mammals indicates that oxons form in vivo via hepatic metabolism. Therefore, it is likely that the current battery

of terrestrial toxicity

tests with mammals also reflect the toxicity of oxons to some extent. Given these lines of evidence, the uncertainty associated with lack of oxon toxicity

data is judged to not materially affect the current risk assessment conclusions. However, if new uses are proposed for TM in the future, the issue of oxon data would need to be re - evaluated.

**a. Age Class and Sensitivity of Effects Thresholds**  It is generall y recognized that test organism age may have a significant impact on the observed sensitivity

t o a toxicant. The screening risk assessment acute toxicity data for fish are collected on juvenile fish and aquatic invertebrate acute testing is performed on recommended immature age classes. Similarly , acute dietary testing with birds is also performed on juveniles, with mallard being 5 - 10 day s old and quail at 10 - 14 day s of age. Testing of juveniles may

overestimate the toxicity of direct acting pesticides in adults. As juvenile organisms do not have fully developed metabolic sy stems, they may not po ssess the ability to transform and detoxify xenobiotics equivalent to the older/adult organism. The screening risk assessment has no current provisions for a generall y applied method that accounts for this uncertainty. In so far as the available toxicity data may provide ranges of sensitivity information with respect to age class, the risk assessment uses the most sensitive life - stage information as the conservative screening endpoint. **b. Lack of Effects Data for Amphibians and Reptiles**  Currently , toxicity

studies on amphibians and reptiles are not required for pesticide registration. Since these data are lacking, the Agency uses fish as surrogates for aquatic - phase amphibians and birds as surrogates for terrestrial - phase amphibians and reptiles. If other species are more or less sensitive to TM than the surrogates, risks may be under- or overestimated, respectivel y. The Agency is not limited to a base set of surrogate toxicity information in establishing risk assessment conclusions. The Agency also considers toxicity

data on non - standard test species when available. Further research is needed to determine whether, in general, reptiles and terrestrial - phase amphibians are suitabl y represented by bird species in assessing risks for TM and fish are an appropriate surrogate for aquatic - phase amphibians.

### 109 **c. Use of the Most Sensitive Species Tested**  Although the screening - level risk assessment relies on a selected toxicity endpoint from the most sensitive species tested, it does not necessarily mean that the selected toxicity endpoints reflect sensitivity

of the most sensitive species existing in a gi ven environment. The relative position of the most sensitive species tested in the distribution of all possible species is a function of the overall variability

among species to a particular chemical. The relationship between the sensitivity

of the most sensitive tested species versus wild species (including listed species) is unknown and a source of significant uncertainty. In addition, in the case of listed species, there is uncertainty regarding the relationship of the listed species' sensitivity and the most sensitive species tested.

### 110



## V. **REFERENCES TO OPEN LITERATURE AND GOVERNMENT REPORTS**  FAO, 2000. Food and Agricultural Organization of the United Nations. FAO Pesticide Disposal Series 8. Assessing Contamination: A reference Manual. Appendix 2. Param eters of pesticides that influence processes in the soil. Editorial Group, FAO Information Division: Rome. http://www.fao.org/DOCREP/003/X2570E/X2570E00.HTM Fungicide Resistance Action Commi ttee. FRAC code list: Fungicides sorted by mode of action. 2009. http://www.frac.info/frac/publication/anhang/FRAC_CODE_LIST.pdf Krupke CH, Hunt GJ, Eitzer BD, Andino G, Given K . 2012. Multiple Routes of Pesticide Exposure for Honey

bees Living Near Agricultural Fields. PL oS ONE 7(1): e29268. doi:10.1371/journal.pone.0029268 US EPA. 2004a. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs, U.S. Environmental Protection Agency: Endangered and Threatened Species Effects Determinations. Office of Prevention, Pesticide, and Toxic Substances. US EPA. 2000. Methods for Measuring the Toxicity and Bio accumulation of Sediment Associated Contaminants with Freshwater Invertebrates, Second Edition, EPA 600/R - 99/064 . Office of Research and Development. Washington, DC 20460.

### 111



## A **PPENDIX** 

## A. **E NVIRONMENTAL**  

## F **ATE** 

## S **TUDY** 

## B **IBLIOGRAPHY MRID No.**  

### 00156106 Yoshimura, J.; Mikami, N.; Matsuda, T.; et al. (1985) Degradation of the

Fungicide Tolclofos - methyl in Soils under Aerobic, An - aerobic and Sterilized Conditions. Unpublished study prepared by

Takarazuka Research Center, Sumitomo Chemical Co., Ltd. 29 p. 00156111 Ali, S.; Cahill, W. (1985) Dissipation of Tolclofos - methyl in Soil: Project No.

411968. Unpublished study prepared by

Velsicol Chemical Corp. 15 p. 00163641 Forbis, A.; Bunch, B. (1986) Uptake, Depuration and Bioconcentra - tion of

[Carbon 14] - Rizolex by

Bluegill Sunfish (Lepomis macro - chirus): ABC Final Report #33971. Unpublished study prepared by

Analy tical Biochemistry Laboratories Inc. 42 p. 00163642 Yu, C.; Guirguis, A. (1986) Metabolism of Tolclofos - methyl in Blue - gill

Sunfish (L epomis macrochirus): Project No. 411968: Report No. 7. Unpublished study

prepared by

Sandoz Crop Protection Corp. 15 p. 41422902 Katagi, T.; Takahashi, N. (1988) Photoly sis o f Tolclofos - methyl in Water:

Study Number: PHW 87001. Unpublished study prepared by

Sumitomo Chemical Co., Ltd. 39 p. 41701801 Pesselman, R. (1990) Vapor Pressure Determination of Rizolex: Final Report:

Lab Project Number: 6001 - 555. Unpublished study prepar - ed b y Hazleton Laboratories America, Inc. 32 p. 41714701 Ekdawi, M.; Yu, C. (1990) Hydrol ys is of Tolclofos - methyl: Lab Pro - ject

Number: 480545: 1. Unpublished study prepared by

Sandoz Crop Protection Corp. 43 p. 42273301 Mikami, N.; Kono, A.; Matsuo, M.; et al. (1991) Adsorption and Desorption of

?carbon 14| - Rizolex in Soils: Lab Project Number: ADS91002. Unpublished study prepared by

Sumitomo Chemical Co., Ltd. 68 p. 42536001 Concha, M.; Ruzo, L .; Shepler, K. (1992) Sun light Photodegradation of Phenyl -

?carbon 14| Rizolex on Soil: Lab Project Number: 232W - 1: P232W: QM - 21 - 0036. Unpublished study prepared b y PTRL - West, Inc. 116 p. 42703201 Itoh, K.; Mikami, N.; Matsuo, M.; et al. (1993) Aerobic Soil Metabolism of

(carbon 14) - Rizolex: L ab Project Number: SOI91001: QM - 30 - 0037. Unpublished study

prepared by

Sumitomo Chemical Company , Ltd. 167 p. 42818301 Kono, A.; Mikami, N. (1993) Anaerobic Soil Metabolism of (carbon 14) -

Rizolex: L ab Project Number: SOI 91003: QM - 30 - 0038. Unpublished study prepared b y Sumitomo Chemical Co., Ltd. 152 p.

### 112

43128101 Mikami, N.; Itoh, K. (1993) Anaerobic Aquatic Soil Metabolism of (carbon 14) -

Rizolex: L ab Project Number: SOI 91005. Unpublished study prepared by Sumitomo Chemical Co., Ltd. 206 p. 48341901 Okada, Y. (2001) Henry's L aw Constant for Tolclofos - Meth yl . Project Number:

201000338, HEN2001B, QP/0096. Unpublished study prepared by

Sumitomo Chemical Co. 5 p. 48341912 Bondarenko, S. (2010) UV/Visible Absorption of Tolclofos - Meth yl . Project

Number: 201000266, 37636. Unpublished study prepared by

Valent U.S.A. Corporation. 47 p. 48341913 Bondarenko, S. (2010) Tolclofos - Meth yl : Determination of n - Octanol/Water

Partition Coefficient (Pow) b y High Performance Liquid Chromatography (HPL C). Project Number: 201000270, 37631. Unpublished study prepared by Valent U.S.A. Corporation. 55 p. 48341914 Concha, M. (2010) Solubility of Tolclofos - Meth yl in Water. Project Number: 200900184, 1019W/1, QP/0095. Unpublished study prepared by

PTRLWest, In c. 53 p. 48341919 Gohre, K. (2009) V - 10178: Soil Adsorption/Desorption. Project Number:

200900665, VP/32699. Unpublished study prepared by

Valent U.S.A. Corporation. 93 p. 48341921 Lewis, C. (2001) (Carbon 14) - Tolclofos - Methyl: Hydroly tic Stability . Project Number: 200900116, 333/147. Unpublished study prepared by

Covance Laboratories, Ltd. 135 p. 48341923 Lewis, C. (1995) (Carbon 14) - Tolclofos - Methyl: Laboratory Study : Aerobic Degradation of PhenylLabel in Three Soils. Project Number: 200900115, 194/ 84, QM/51/0042. Unpublished study prepared by

Hazleton UK. 154 p. 48341924 Lewis, C. (2001) (Carbon 14) - Tolclofos - Methyl: Soil Metabolism and

Degradation. Project Number: 200900113, 333/145, QM/0049. Unpublished study prepared by

Covance Laboratories, Ltd . 105 p. 48341925 Kodaka, R.; Nambu, K.; Nishioka, K.; et al. (1999) Addendum Report

Concerning the Aerobic Degradation of [(Carbon 14) - Phenyl] Tolclofos - Methyl in Three Soils. Project Number: 200900112, SOI 9900B, QM/0046. Unpublished study prepared by Sumitomo Chemical Co. 11 p. 48341926 Lewis, C. (2001) (Carbon 14) - Tolclofos - Methyl: Degradation and Retention in

Water - Sediment Sy stems. Project Number: 200900114, 333/146, QM/0050. Unpublished study

prepared by

Covance Laboratories, Ltd. 116 p.

### 113

48341916 Croucher, A. 2001. T olclofos - methyl: validation of an analy tical method for the determination of residues in soil. Unpublished study p erformed by

C ovance Laboratories Ltd., North Yorkshire, England; sponsored by Sumitomo Chemical Company Ltd., Hyogo, Japan; and sub mitted by V alent U.S.A. Corporation (pp. 1, 1i, 10; Appendix 6, p. 42). C ovance Study N o.: 333/153 (p. 1). S umitomo Report No.: QA - 0073. E xperimental start date March 12, 2001 and completion date May 17, 2001 (p. 5). Final report issued October 11, 200 1 (p. 1). 48341918 Wolf, S. 2001. Validation of a multi - residue method for the determination of

tolclofos - methyl in surface water. Unpublished study performed by

RCC Ltd., Itingen, Switzerland; sponsored b y Sumitomo Chemical Co., Ltd., Hyogo, Japan; and submitted by

Valent U.S.A. Corporation (p. 3; Appendix II, p. 40). RCC Study

No.: 835503 (p. 1). Sumitomo Report No.: QA - 0076. Experimental start date October 4, 2001, and completion date October 19, 2001 (p. 9). Final report issued November 14, 200 1 (p. 1). 48341917 Wolf, S. 2001. Validation of a multi - residue method for the determination of

tolclofos - methyl in drinking water. Unpublished study performed b y RCC Ltd., Itingen, Switzerland; sponsored b y Sumitomo Chemical Co., Ltd., Hyogo, Japan; and submitted by

Valent U.S.A . Corporation (p. 3; Appendix II, p. 40). RCC Study

No.: 833872 (p. 1). Sumitomo Report No.: QA - 0075. Experimental start date October 4, 2001, and completion date October 22, 2001 (p. 9). Final report issued November 12, 2001 (p. 1). 48842101 Green, C., 2012. Tolclofos - methyl: Determination of Tolclofos - methyl in

Drinking Water, Laboratory Project Identification VP - 38290; submitted by Valent U.S.A. Corporation, Valent Technical Center, 6560 Trinity Court, Dublin, California 94568; July

10, 2012; 30 p ages., 2001. 48842102 Green, C., 2012. Tolclofos - methyl: Determination of Tolclofos - methyl in Soil,

Laboratory

Project Identification VP - 38287; submitted by Valent U.S.A. Corporation, Valent Technical Center, 6560 Trinity Court, Dublin, California 94568; July

10, 2012; 30 pages., 2001. 48842103 Green, C., 2012. Tolclofos - methyl: Determination of Tolclofos - methyl in Surface

Water, Laboratory

Project I dentification VP - 38293; submitted by Valent U.S.A. Corporation, Valent Technical Center, 6560 Trinity Court , Dublin, California 94568; July

10, 2012; 30 pages., 2001.

### 114



## A **PPENDIX** 

## B **. E**  **COTOXICITY** 

## S **TUDY** 

## B **IBLIOGRAPHY** 

### 71 **- 1**  **Avian Single Dose Oral Toxicity MRID**  **Citation Reference** 156112 Roberts, N.; Hakin, B. (1981) The Acute Oral Toxicity (LD50) of S - 3349 to the Mallard Duck: HRC Rept. No. SMO/137/81739. Unpub - lished study prepared by Huntingdon Research Centre. 14 p. 156113 Roberts, N.; Hakin, B. (1982) The Acute Oral Toxicity (LD50) of S - 3349 to the Bobwhite Quail: HRC Rept. No. SMO 138/81880. Un - published study prepared by Huntingdon Research Centre. 15 p. 156114 Roberts, N.; Hakin, B. (1981) The Acute Oral Toxicity (LD5 0) of S - 3349 to the Ring - necked Pheasant: HRC Rept. No. SMO/135/81740. Unpublished study prepared b y Huntingdon Research Centre. 15 p. 

### 71 **- 2**  **Avian Dietary Toxicity MRID**  **Citation Reference** 156115 Beavers, J. (1985) Technical Rizolex: A Dietary LC50 Study

with the Mallard: Final Report: Project No. 107 - 207. Unpublished study prepared by

Wildlife International Ltd. 16 p. 156116 Beavers, J. (1985) Technical Rizolex: A Dietary LC50 Study

with the Bob white: Final Report: Rept. No. 107 - 206. Unpublished study prepared by

Wildlife International Ltd. 15 p. 

### 71 **- 4**  **Avian Reproduction MRID**  **Citation Reference** 40190201 Beavers, J.; Jaber, M. (1986) Rizolex Technical: A One Generation

Reproduction Study

with the Bobwhite (Colinus virginianus): Project No. 107 - 213. Unpublished study

prepared by

Wildlife International Ltd. 118 p. 40190202 Beavers, J.; Jaber, M. (1986) Riz olex Technical: A One Generation

Reproduction Study

with the Mallard (Anas platyrhy nchos): Project No. 107 - 214. Unpublished study

prepared by

Wildlife International Ltd. 119 p. 

### 72 **- 1**  **Acute Toxicity to Freshwater Fish MRID**  **Citation Reference**

### 115

15 6117 Takimoto, Y.; Kagoshima, M. (1982) The Acute Toxicity of S - 3349 to Rainbow Trout (Salmo gairdneri). Unpublished study prepared by

Sumitomo Chemical Co., Ltd. 11 p. 156118 Takimoto, Y.; Kagoshima, M.; Ashida, S.; et al. (1981) The Acute Toxicity of

S - 3349 to Carp (Cy

prinus carpio) and Killifish (Ory- zias latipes). Unpublished study prepared by

Sumitomo Chemical Co., Ltd. 12 p. 156119 Takimoto, Y.; Kagoshima, M.; Ashida, S . (1981) The Acute Toxicity of S - 3349 to Guppy (Poecilia reticulata). Unpublished study prepared by

Sumitomo Chemical Co., Ltd. 8 p. 163558 Bowman, J. (1986) Acute Toxicity of Rizolex Technical to Bluegill Sunfish (Lepomis macrochirus): Rept. #34647. Unp ublished study prepared by Analy tical Bio - Chemistry

L aboratories Inc. 48 p. 41400301 McAllister, W. (1989) Acute Flow - through Toxicity of Rizolex Tech - nical to Bluegill (Lepomis macrochirus): Lab Project Number: 37795. Unpublished study prepared by

Anal yt ical Bio - Chemistry L aboratories, Inc. 169 p. 48737502 Dionne, E. 1998. Desmethyl - T olclofos methyl - Acute Toxicity to Rainbow Trout (Oncorh yn chus m ykiss) Under Static Acute Conditions Lab ID Number: 13048.6177 

### 72 **- 2**  **Acute Toxicity to Freshwater Invertebrates**  **MRID Citation Reference**  156120 Takimoto, Y.; Kagoshima, M. (1982) The Acute Toxicity of S - 3349 to Daphnia pulex. Unpublished study prepared b y Sumitomo Chemical Co., Ltd. 5 p. 40096301 Forbis, A. (1987) Acute Toxicity of Rizolex Technical to Daphnia magna: ABC Laboratory

Project ID: #35337. Unpublished study prepared by

Anal yt ical Bio Chemistry

L aboratories, Inc. 44 p. 41400302 Burgess, D. (1989) Acute Flow - through Toxicity of Rizolex to Daphnia magna: Lab Project Number: Final Report #37796. Unpub - lished study prepared by Analy tical Bio - Chemistry

L aboratories, Inc. 157 p. 43528001 Murrell, H.; Bucksath, J. (1994) Acute Toxicity of Rizolex to Daphnia magna: Final Report: Lab Project Number: 41242. Unpublished study prepared by

ABC Labs, Inc. 271 p. 48737501 Dionne, E. 1998. Desmethyl - Tolclofos methyl - Acute T ox ic ity to D aphnids (Da phnia magna) Under Sialic Conditions . Lab ID Number: 13048.6178 

### 72 **- 4**  **Fish Early Life Stage/Aquatic Invertebrate Life Cycle Study MRID**  **Citation Reference**

### 116

41400303 Burgess, D. (1989) Chronic Toxicity of Rizolex to Daphnia magna under Flow through Test Conditions: L ab Project Number: 37552. Unpublished study prepared b y Anal yt ical Bio - Chemistry L abora - tories, Inc. 29 p. 41624501 Burgess, D. (1989) Chronic Toxicity of Rizolex to Daphnia magna under Flow through Test Conditions: L ab Project Number: 37552. Unpublished study prepared b y Anal yt ical Bio - Chemistry L abora - tories, Inc. 417 p. 42106501 Cohle, P.; Leak, T. (1991) Earl y Li fe Stage Toxicity of Rizolex Technical to Rainbow Trout (Oncorh ynchus mykiss) in a Flow - through S ys tem: Final Report: L ab Project Number: 38586R. Un - published study prepared by

ABC Laboratories, Inc. 1476 p. 

### 141 **- 1**  **Honeybee acute contact**  **MRID Cit**  **ation Reference** 156122 Takarazuka Research Center (1983) Toxicity of Tolclofos - methyl against Honey bee s, Apis mellifera. Unpublished study prepared b y Sumitomo Chemical Co., Ltd. 2 p. 163557 Sumitomo Chemical Co., Ltd. (1983) Toxicity of Tolclofos - methyl against Honey bee s, Apis mellifera: Doc. Code QW - 30; Ref. No. - 0018. Unpublished study . 3 p. 41794202 Winter, P.; Hoxter, K.; Smith, G. (1990) Rizolex: An Acute Contact Toxicity

Study with th e Honey

bee : L ab Project Number: 131 - 141. Unpublished study prepared b y Wildlife International, Ltd. 15 p. 

### 165 **- 4**  **Bioaccumulation in fish MRID**  **Citation Reference** 163641 Forbis, A.; Bunch, B. (1986) Uptake, Depuration and Bioconcentration of [Carbon

14] - Rizolex by

Bluegill Sunfish (L epomis macrochirus): ABC Final Report #33971. Unpublished study

prepared by

Anal yt ical Biochemistry L aboratories Inc. 42 p. 163642 Yu, C.; Guirguis, A. (1986) Metabolism of Tolclofos - methyl in Blue - gill Sunfish

(Lepomis macrochirus): Project No. 411968: Report No. 7. Unpublished study prepared b y Sandoz Crop Protection Corp. 15 p. 48737503 Herczog, K; Panthani , A. 2004. Bioconcentration of 14 

### C Tolclofos - methyl by Bluegill

Sunfish (L epomis macrochirus) . Lab ID Number: 016416 - 1 

### 850.1010 **Aquatic invertebrate acute toxicity, test, freshwater daphnids**

### 117

**MRID Citation Reference**  48737501 Dionne, E. (1998) Desmethyl - Tolclofosmethyl: Acute Toxicity to Daphnids (Daphnia magna) Under Static Conditions. Project Number: 200900134, 13048/6178, QW/0054. Unpublished study prepared by

Springborn Smithers L aboratories. 50p. 

### 850.1025 **Oyster acute toxicity test (shell deposition) MRID**  **Citation R eference**  48341928 Gallagher, S.; Kendall, T.; Krueger, H. (2010) A 96 - Hour Shell Deposition Test with

the Eastern Oy ster (Crassostrea virginica) (Tolclofos - Methyl). Project Number: 201000049, 263A/110A. Unpublished study prepared by

Wildlife International , Ltd. 57 p. 

### 850.1035 **Mysid acute toxicity test MRID**  **Citation Reference** 48341929 Palmer, S.; Schneider, S.; Kendall, T.; et al. (2010) V - 10178: A 96 - Hour Static Renewal Acute Toxicity

Test with the Saltwater My sid (Americam ys is bahia). Project Number: 201000249, 263A/112, VP/37053. Unpublished study prepared by Wildlife International, Ltd. 58 p. 

### 850.1075 **Fish acute toxicity test, freshwater and marine MRID**  **Citation Reference** 48341930 Sousa, J. (2003) Tolclofos - Methyl Acute Toxicity to Rainbow Trout (Oncorhy nchus my kiss) Under Flow - Through Conditions. Project Number: 13048/6416, QW/0071, 040703/RBT/FT/SUMITO. Unpublished study prepared b y Springborn Viscient Laboratories. 55 p. 48341931 Thomas, S.; Kendall, T.; Krueger, H. (2010) V - 10178: A 10 - Day Survival and Growth Sediment Toxicity Test with the Freshwater Amphipod (Hyalella azteca) Using Spiked Sediment. Project Number: 263A/113, VP/37063, 201000330. Unpublished study

prepared by

Wildlife International, Ltd. 88 p. 48341932 Palmer, S.; Schneider, S.; Kendall, T.; et al. (2010) V - 10178: A 96 - Hour Static Renewal Acute Toxicity

Test with the Sheepshead Minnow (Cy prinodon variegatus). Project Number: 201000250, 263A/111, VP/37051. Unpublished study prepared by Wildlife International, Ltd. 5 5 p. 48737502 Dionne, E. (1998) Desmethyl - Tolclofosmethyl: Acute Toxicity to Rainbow Trout (Oncorh yn chus my

kiss) Under Static Acute Conditions. Project Number: 200900135, 13048/6177, QW/0055. Unpublished study prepared by

Springborn Smithers Laboratories. 50p. 

### 850.1350 **Mysid chronic toxicity test MRID**  **Citation Reference**

### 118

48341933 Palmer, S.; Claude, M.; et al. (2009) V - 10178: A Flow - Through Life - Cycle Toxicity

Test with the Saltwater My sid (Americam ys is bahia). Project Number: 201000324, 263A/115C, VP/37125. Unpublished study prepared by

Wildlife International, Ltd. 131 p. 

### 850.1400 **Fish early -**  **life stage toxicity test MRID**  **Citation Reference** 48341934 Rose, A. (2010) Toclofos - Methyl: Salt Water Fish Earl y Li fe - Stage Waiver Request.

Project Number: 201000332, VP/37837. Unpublished study prepared by

Valent U.S.A. Corporation. 6 p. 

### 850.2100 **Avian acute oral toxicity test MRID**  **Citation Reference** 48341936 Hubbard, P.; Beavers, J. (2010) V - 10178: An Acute Oral Toxicity Study with the Zebra Finch (Poephilia guttata). Project Number: 201000053, 263/164. Unpublished study prepared by

Wildlife International, Ltd. 46 p. 

### 850.4100 **Terrestrial plant toxicity, Tier 1 (seeding emergence) MRID**  **Citation Reference** 48341937 Shen, S. (2010) Rizolex Flowable Fungicide - Waiver for Non - Applicable Non Target Plant Protection Studies. Project Number: 201000326, VP/37701. Unpublished study

prepared by

Valent U.S.A. Corporation. 8 p. 48341938 Shen, S. (2010) Waiver Request: Toclofos Methyl Seed Tr eatment Registration Tier I

Seedling Emergence, Tier I Vegetative Vigor, Tier I Aquatic Plant Growth, Honey bee Acute Contact. Project Number: 201000335, V/37701. Unpublished study prepared b y Valent U.S.A. Corporation. 8 p. 

### 850.4150 **Terrestrial plan t toxicity, Tier 1 (vegetative vigor)**  **MRID Citation Reference**  48341937 Shen, S. (2010) Rizolex Flowable Fungicide - Waiver for Non - Applicable Non Target Plant Protection Studies. Project Number: 201000326, VP/37701. Unpublished study

prepared by

Valent U.S.A. Corporation. 8 p. 48341938 Shen, S. (2010) Waiver Request: Toclofos Methyl Seed Treatment Registration Tier I

Seedling Emergence, Tier I Vegetative Vigor, Tier I Aquatic Plant Growth, Honey bee Acute Contact. Project Number: 201000335, V/37701. Unpublished study prepared b y Valent U.S.A. Corporation. 8 p. 

### 850.4400 **Aquatic plant toxicity test using Lemna spp. Tiers I and II MRID**  **Citation Reference** 48341937 Shen, S. (2010) Rizolex Flowable Fungicide - Waiver for Non - Applicable Non Target Plant Protection Studies. Project Number: 201000326, VP/37701. Unpublished study

prepared by

Valent U.S.A. Corporation. 8 p.

### 119

48341938 Shen, S. (2010) Waiver Request: Toclofos Methyl Seed Treatment Registration Tier I

Seedling Emergence, Tier I Vegetative Vigor, Tier I Aquatic Plant Growth, Honey bee Acute Contact. Project Number: 201000335, V/37701. Unpublished study prepared b y Valent U.S.A. Corporation. 8 p. 

### 850.5400 **Algal toxicity, Tiers 1 and II MRID**  **Citation Reference** 48341937 Shen, S. (2010) Rizolex Flowable Fungicide - Waiver for Non - Applicable Non Target Plant Protection Studies. Project Number: 201000326, VP/37701. Unpublished study

prepared by

Valent U.S.A. Corporation. 8 p. 48341938 Shen, S. (2010) Waiver Request: Toclofos Methyl Seed Treatment Registration Tier I

Seedling Emergence, Tier I Vegetative Vigor, Tier I Aquatic Plant Growth, Honey bee Acute Contact. Project Number: 201000335, V/37701. Unpublished study prepared b y Valent U.S.A. Corporation. 8 p. 48737505 Hoberg, J. (1998) Desmethyl - T olclofosmeth yl : Toxicity to the Freshwater Green Alga (Scenedesmus subspicatus). Project Number: 200900098, 13048/6176, QW/0053. Unpublished study prepared by

Springborn Smithers L aboratories. 62p. 48737506 Sayers, L. (2003) Tolclofosmethyl: Toxicity to the Freshwater Green Alga (Scenedesmus subspicatus). Project Number: 200900097, 13048/6415, QW/0072. Unpublished study

prepared by

Springborn Smithers Laboratories. 61p. 

### 850.1740 **Whole sediment: acute marine invertebrates MRID**  **Citation Reference** 48341935 Thomas, S.; Kendall, T.; Krueger, H. (2010) V - 10178: A 10 - Day Survival Toxicity Test with the Marine Amphipod (Leptocheirus plumulosus) Using Spiked Sediment. Project Number: 201000339, 263A/114, VP/37058. Unpublished study prepared by Wildlife International, Ltd. 121 p. 

### 850.1790 **Chironomid Sediment Toxicity Test MRID**  **Citation Reference** 48737504 Putt, A. (2002) Tolclofos - methyl: The Full L ife - Cycle Toxicity to Midge (Chironomus riparius) Under Static Conditions. Project Number: 200900139, 13048/6331, QW/0063. Unpublished study prepared by

Springborn Smithers Laboratories. 101p. **Submitted Mammalian Studies**  MRID Author(s) Year Title

### 120

MRID Author(s) Year Title 

### 156124 Ky

noch, S. 1985 Acute Oral Toxicity to Rats of Rizolex Technical: HRC Rept. No.85677D/VCL 83/AC . Unpublished study

prepared by

Huntingdon Research Centre Ltd. 10 p 156140 Pence, D. 1982 Chronic Toxicity Study in Rats: S3449 : Final Report: Project No. 343 - 118. Un1published study prepared b y Hazleton Laboratories America, Inc. 1939 p. 156137 Suzuki, T

Okuno, Y Hiromori, T 1978 Nine - month Feeding Study of S - 3349 in mice. Unpublished study

prepared by

Institute for: Biological Science, Hyogo, Japan. 185 p. 156121 Takimoto, Y.

Yasutani ya, T. 1983 The Effect of Tolclofos - methyl on the Growth of the Green Alga, Scenedesmus quadricauda. Unpublished study

prepared by

Sumitomo Chemical Co. Lt d 20 p . 156128 Segawa, T 1978 Acute Toxicity Study of S - 3349 in Rats and Mice. Institute of Pharmaceutical Sciences, Hiroshima University , Japan Sumitomo Chemical Company , Ltd., Japan; QT - 71 - 0003 41422901 Morseth, S 1987 Teratology Study of S - 3349 T.G. in Rats. HLA 343 - 192, Sumitomo Chemical Co., Ltd. Osaka, Japan 1561 3 8 Pence, D et al 1979 Subacute Dietary Administration in Dogs S - 3349 Final Report. 343 - 120. Hazleton Laboratories America, Inc. Herndon, Va. Sandoz Crop Protection Chicago, Illinois. 

### 265173 Mihara, K.,

Ohkawa, H., Miyamoto, J 1980 Metabolism of tolclofos - methyl in rats and mice. (Unpublished s tudy No. QM - OO - 0008 performed and submitted by Sumitomo Chemical Co., Ltd., Osaka, Japan

### 121



## A **PPENDIX** 

## C **. D**  **ATA** 

## R**EQUIREMENTS AND** 

## D **ATA** 

## G**APS**

**UNITED ST AT**  **ES ENVIRONMENT AL**  **PROTECTION A GENCY** 

**WA SHINGTON, D.C. 20460** 

**OFFICE OF CHEMCICAL SAFETY AND**  **POLLUTION PREVENTION** 

### PC code: 128905 **DP Barcode: 388586**  **November 3, 2011 MEMORANDUM**  **SUBJECT:** Environmental Fate and Ecological Effects New Chemical Screen for Tolclofos methyl **FROM:** Keith Sappington, Senior Biologist

Larry L iu, Chemist Environmental Risk Branch V Environmental Fate and Effects Division (7507P) **THROUGH:** Mah T. Shamim, Ph.D., Branch Chief

Environmental Risk Branch V Environmental Fate and Effects Division (7507P) **TO:** Lisa Jones, Risk Manager Reviewer,

Mary Woller, Risk Manager, RM - 21 Fungicide Branch, Registration Division (7505P) EFED has completed a new chemical screen of the environmental fate and ecological effects studies submitted by

Valent USA Corporation in support of a new registration for the fungicide, Tolclofos - methyl . This screen included:  A check of the submission to ensure that all studies triggered b y the use pattern are included in the package  An evaluation as to whether each stu dy is reviewable, i.e., has no fatal flaws rendering the study scientifically invalid  Consideration of the submitted waiver requests (detailed under a separate action).**122**



### Please note that this screen is not intended to be a comprehensive evaluation of the q uality of submitted studies. Rather, it is an indication of the completeness of the data package that has been submitted to the Agency . Therefore, studies that pass this screen are not automatically assured of acceptance in support of the respective data requirement. Based on this new chemical screen, the following data gaps are noted:  Photodegradation in water (835.2240)  Aerobic soil metabolism (835.4100)  Anaerobic soil metabolism (835.4200)  Corresponding ECMs for the submitted ILVs In addition to thes e data gaps, we note that tolclofos methyl (a phosphorothionate organophosphate (OP) pesticide), has been shown to form oxon degradates in various environmental fate studies (see summaries below). Oxon degradates can be substantially more toxic than parent organophosphates (up to 100X). Although EFED’s policy regarding data requirements for oxon degradates would ordinarily recommend additional toxicity and fate studies, 14 

### the low toxicity of this chemical combined with its relatively low estimated environm ental concentrations (EECs) indicates that additional data on the oxon degradate would not likely affect the risk assessment conclusions (including endangered species) for the proposed seed treatment uses . However, should new uses of tolclofos methyl be p roposed in the future, the need for oxon - related fate and ecological effects data will be re - evaluated and additional studies may

be requested at that time. A study- by- study

evaluation of data gaps is provided in the following table. Please let us know if you have an y questions or concerns.

14 Guidance for Registration Review Data Requests for Oxon Degradates of Organophosphate Insecticides (OP). Memo from Don Brady (Division Director). March 10, 2009.**123** DATA PACKAGE NEW CHEMICAL SCREEN FOR:



## Tolclofos **- methyl**  **PC Code:** 128905 **Data Requirement Test Species**  **MRID Are Data**  **Reviewable? (Y/N)**  **Study**

**Classifi**   ** cation** **1 Additional** 

**Data Needed?**  **(Y/N) §158.630 WILDLIFE**  **AND AQUATIC ORGANISMS Avian Studies**  850.2100/71 - 1(a) Avian Acute Oral, Quail/Duck Mallard Bobwhite Pheasant 00156112

00156113 00156114 Y

Y A

A N **3** 850.2100 Avian Acute Oral, Passerine zebra finch 48341936 Y N 850.2200/71 - 2(a) Avian Dietary, Quail Bobwhite 00156116 Y A N 850.2200/71 - 2(b) Acute Dietary, Duck Mallard 00156115 Y A N 850.2400/71 - 3 Wild Mammal Toxicity N 850.2300/71 - 4(a) Avian Reproduction, Quail Bobwhite 40190201 Y A N 850.2300/71 - 4(b) Avian Reproduction, Duck Mallard 40190202 Y A N **Terrestrial Field Studies** 850.2500/71 - 5(a) Simulated Terrestrial Field Study N 850.2500/71 - 5(b) Actual Terrestrial Field Study N **Aquatic Studies: Acute** 850.1075/72 - 1 (a) Acute Freshwater Fish, Warmwater Carp, Killifish Guppy Bluegill Bluegill 00156118

00156119 00163558 41400301 Y

Y Y Y S (test sp)

S (test sp) S (precip) S (> LC50) N **3** 850.1075/72 - 1(b) Acute Fish Toxicity, Warmwater (TEP) N 850.1075/72 - 1(c) Acute Freshwater Fish, Coldwater Rainbow trout Rainbow trout 48341930

00156117 Y

Y A (FT)

A (SR) N 850.1075/72 - 1(d) Acute Freshwater Fish, Coldwater (TEP) N**124**

**Data Requirement Test Species**  **MRID Are Data**  **Reviewable? (Y/N)**  **Study**

**Classifi**   ** cation** **1 Additional** 

**Data Needed?**  **(Y/N)** 850.1010/72 - 2(a) Acute Freshwater Invertebrate D. pulex D. magna 00156120

43528001 Y

Y S (24h)

A N **3** 850.1010/72 - 2(b) Acute Freshwater Invertebrate (TEP) N 850.1075/72 - 3(a) Acute Estuarine/Marine, Fish Sheepshead Minnow 48341932 Y NR N 850.1075/72 - 3(d) Acute Estuarine/Marine, Fish (TEP) N 850.1025/72 - 3(b) Acute Estuarine/Marine, Bivalve (shell deposition) 850.1055 (embryo/lavae) Eastern oyster 48341928 Y NR N 850.1025/72 - 3(e) Acute Estuarine/Marine, Bivalve (shell deposition) 850.1055 (embryo/larvae) (TEP) N 850.1035/72 - 3(c) Acute Estuarine/Marine, Crustacean (mysid) 850.1045 (penaeid) My sid 48341929 Y NR N 850.1035/72 - 3(f) Acute Estuarine/Marine, Crustacean (mysid) 850.1045 (penaeid) (TEP) N **Aquatic Studies: Chronic** 850.1400/72 - 4(a) Fish Early - Life Stage (FW, SW) Rainbow trout Saltwater fish 42106501

48341934 Y

W.R. Waiver

request accepted N 850.1300/72 - 4(b) Freshwater Invertebrate Life Cycle D. magna 41400303 41624501 Y A N 850.1350/72 - 4(b) Saltwater Invertebrate Life Cycle My sid 48341933 Y NR N **Aquatic Studies: Other** 850.1500/72 - 5 Fish Life Cycle N 850.1735 Whole Sediment Acute Invertebrate, Freshwater Hyalella azteca 48341931 Y NR N 850.1740 Whole Sediment Acute Invertebrate, Saltwater Leptocheirus plumulosus 48341935 Y NR N 850.1760, 1770Whole Sediment Chronic Invertebrate, Freshwater (midge, amphipod) N**125**

**Data Requirement Test Species**  **MRID Are Data**  **Reviewable? (Y/N)**  **Study**

**Classifi**   ** cation** **1 Additional** 

**Data Needed?**  **(Y/N)** 850. 1780 Whole Sediment Chronic Invertebrate, Saltwater (amphipod) N 850.1950/72 - 7 Simulated or Actual Aquatic Field Study N **§158.660 PLANT PROTECTION** 850.4100/122 - 1(a) Seedling Emergence, Tier 1 48341937 48341938 W.R. Waiver request accepted N 850.4150/122 - 1(b) Vegetative Vigor, Tier 1 48341937 48341938 W.R. Waiver request accepted N 850.5400/122 - 2 Aquatic Plant Grow th, Algae, Tier 1 Green algae 48341937 48341938 00156121 W.R.

Y Waiver

request accepted A N 850.4400/123 - 2 Aquatic Plant Grow th, Vascular Plant, Tier 1 48341937 48341938 W.R. Waiver request accepted N 850.4100/123 - 1(a) Seedling Emergence, Tier 2 N 850.4150/123 - 1(b) Vegetative Vigor, Tier 2 N 850.4400/123 - 2 Aquatic Plant Grow th, Vascular Plant, Tier 1 N 850.5400/123 - 2 Aquatic Plant Grow th, Algae, Tier 2 N 850.4300, 124 - 1 Terrestrial Field Study, Tier 3 N 850.4450, 124 - 2 Aquatic Field Study, Tier 3 N **§158.630 NONTARGET INSECT TESTING** 850.3020/141 - 1 Honeybee Acute Contact 48341938 41794202 W.R.

Y (TGAI) A N 850.3030/141 - 2 Honeybee, Residues on Foliage N Non - Guideline Study: Honeybee, acute oral N 850.3040/141 - 5 Field Test for Pollinators N**126**

**Data Requirement Test Species**  **MRID Are Data**  **Reviewable? (Y/N)**  **Study**

**Classifi**   ** cation** **1 Additional** 

**Data Needed?**  **(Y/N) §158.1300 ENVIRONMENTAL FATE**  **Degradation Studies -**  **Lab:** 835.2120/161 - 1 Hydrolysis 156104 41714701 48341921 Y

Y Y S

A U (prelim.) N 835.2240/161 - 2 Photodegradation In Water 156105 41422902 Y

Y S

S (upgradable) **Y 2**  835.2410/161 - 3 Photodegradation on Soil 42536001 Y A N 835.2370/161 - 4 Photodegradation in Air 48341945 Y S (preliminary) N **Me tabolism** **Studies -**  **Lab:**

835.4100/162 - 1 Aerobic Soil 4156106 42703201 48341922 48341923 48341925 (addendum to 48341923) 48341924 Y S A (1 soil only) S (prelim.) S (prelim.) S (prelim.) S (prelim.) **Y 3,4** 

835.4200/162 - 2 Anaerobic Soil 42818301 Y A (1 soil only) **Y 4**  835.4300/162 - 4 Aerobic Aquatic 158107 48341926 Y S S (prelim.) N 835.4400/162 - 3 Anaerobic Aquatic 43128101 Y A N **Mobility Studies: 127** 

**Data Requirement Test Species**  **MRID Are Data**  **Reviewable? (Y/N)**  **Study**

**Classifi**   ** cation** **1 Additional** 

**Data Needed?**  **(Y/N)**

835.1230/163.1 Leaching Adsorption/Desorption 835.1240 156108 156109 42273301 42273302 48341919 (two soils) Referred to MRID 42273301 for additional Koc Y S S A A S (prelim.) N **3**

835.1410/163 - 2 Volatility (Lab) 156110 40352201 Waiver request Y U U N **5 Dissipation Studies**  **- Field:** 

835.6100/164 - 1 Terrestrial 156111 43785001 43785002 43785003 Waiver request Y S A A A N

835.6200/164 - 2 Aquatic (Sediment) Waiver request Y N 835.8100/163 - 3 Volatility (Field) Waiver request Y N **Accumulation Studies:** 850.1730/72 - 6/165 - 4 Fish BCF 163641 163642 Y U (exposure conc.) N **5 Analytical Methods**  ECMs/ILVs ( 48341916 ; 48842102) 48341917 ; 48842101) 48341918 ; 48842103) Y **Y 6** 

**FOOTNOTES:** 1. Note: study classifications of older (previously reviewed) studies is indicated by the following: A=acceptable, S= supplemental; U= unacceptable. Study classifications of newer data submissions are indicated as being “preliminary” (prelim. )**128**

or not yet reviewed (NR). W.R. = waiver request. 2. Study is upgradable per the summary on the aqueous photolysis study below. 3. Study on the oxon degradate (TMO and/or DM - TMO) is not requested for the proposed seed treatment use. However, the need for this study may be triggered by additional uses i f proposed in the future. 4. Data requested for additional soil types according to current OSCPP test guidelines. 5. Study of parent tolclofos methyl (with measurement of oxon degradates) is not being requested for this proposed use. However, the need fo r this study may be triggered by additional uses if proposed in the future. 6. Corresponding ILVs should be submitted.**129**



## A **PPENDIX** 

## D **. E**  **COTOXICITY** 

## S **TUDY** 

## S **UMMARIES Fish, Acute Toxicity**  **156117** Miyamoto et al (1982) conducted a 96 -hour static -renewal study on juvenile rainbow trout, Oncorhynchus mykiss weighing 0.85 ± 0.14 g on average. 10 trout were exposed in 20 - L glass aquaria to nominal concentrations of 0.05, 0.1, 0.18, 0.32, 0.56, 0.75, 1, 1.8, 3.2 mg ai/L TGAI (97.8%). Test vessels were renewed every 24 hours. Actual test measurements at the 0.56 ppm every 24 hours suggested that actual concentrations ranged from 72.5% to 96.4% of nominal. Test temperature was 15C, pH ranged from 7.2 to 7.7, and dissolved oxygen was > 7 mg/L. Control mortality was 0% and the 96 - hour LC 50 is estimated to be 0.87 ppm (Probit). Symptoms of intoxication for included (in the order of occurrence): abnormal respiration (slackness), lethargy, loss of equilibrium, darkening and death. At 0.05 ppm, no adverse effects were observed. No precipitation was reported in this study despite test concentrations that exceeded solubility limit of 0.7 - 1.0 ppm and precipitation problems reported on other similar studies. It is noted that this study used an unusual solvent (10 parts dimethylsulfoxide and 10 parts polyoxyethylene hydrogenated castor oil) that evidently was adequate to achieve dose response at the levels tested. This study is considered supplemental because of a number of deficiencies including: frequency of temperature determination was not indicated, the lighting schedule was not specified, aeration was not specified, no total residual chlorine measurement was made of dilution water (dechlorinated tap water), t he solvent was not one of those normally accepted; however, there was no mortality in the solvent control. **48341930** In a 96 -h acute toxicity study, Sousa et al (2003) exposed rainbow trout ( Oncorhynchus mykiss ) to Tolclofos - methyl TGAI (97.8%) at nominal concentrations of 0 (negative and solvent controls), 0.21, 0.36, 0.59, 0.99, and 1.6 mg ai/L under flow - through conditions. Mean - measured concentrations were <LOQ (<0.025, controls), 0.17, 0.25, 0.35, 0.61, and 0.80 mg ai/L; a precipitate was noted in tes t solutions as the limit of solubility was approached by these concentrations. Therefore, samples were centrifuged prior to analysis. The 96 -h LC 50 was 0.69 mg ai/L. The NOAEC, based on mortality and sub - lethal effects was 0.35 mg ai/L; loss of equilibrium and lethargy were observed after 6 hours in the 0.61 and 0.80 mg ai/L levels. No mortality occurred in either the negative or solvent controls. Based on the results of this study, tolclofos methyl would be classified as highly toxic to Oncorhynchus myk iss in accordance with the classification system of the U.S. EPA. This toxicity study is classified scientifically sound and satisfies the guideline requirement for a freshwater fish toxicity study. **47837502** Dionne (1998) exposed 10 rainbow trout (0.68 - 1. 8g) to 98.9% DM - TM (a metabolite of tolclofos methyl) in a static system over a period of 96 hours. Nominal concentrations were 18, 30, 50, 84 and 140 mg a.i./L. In addition, a dilution water control was tested (solvents were not used so a solvent control was not necessary). Each test chamber (18.9 L glass aquaria, each containing 15 L of test solution) served as one replicate. Trout were maintained at 14 - 15C and not fed during exposure. For analytical verification of the test item, samples were taken at 0 and 96 hours from all concentrations. QA spike results indicate recovery of 96% to 101% respectively using high performance liquid chromatographic with ultraviolet detection (HPLC/UV) procedure. Mortality and signs of toxicity were assessed at 6 hours aft er test initiation and daily thereafter. Temperature, pH and dissolved oxygen concentrations were also measured**130**

daily. Alkalinity, hardness, and conductivity were measured in a sample of the dilution water at test initiation. The test substance was stable over 96 hours although measure concentrations were 77 - 79% of nominal. Regulatory endpoints are reported as mean measured concentrations. All water quality parameters remained within acceptable limits. Following 96 hours of exposure (test termination), n o mortality or sublethal adverse effects were observed among trout exposed to any treatment level tested or the control. Based on these results, the 96 -hour LC50 was empirically estimated to be greater than 110 mg a.i./L, the highest mean measured concentr ation tested. The No - Observed - Effect Concentration (NOEC) was determined to be 110 mg a.i./L. DM - TM is classified as practically non - toxic to rainbow trout. **00156118** Takimoto et al (1981) exposed juvenile carp ( Cyprinus carpio, avg. weight 0.46g) and kil lifish (Japanese medaka, Oryzias latipes , avg. weight 0.36g) to TM TGAI (99.8%) in a 24 -h static renewal system for 96 - hours. Ten fish of each species were exposed/treatment (1 replicate/treatment). Exposure concentrations were 0, 0.1, 0.18, 0.32, 0.56, 1.0, 1.8, 5.6 and 7.8 mg ai/L. Fish were acclimated 14 days and fasted 2 days prior to testing. Test temperature was 23C, pH was in the range of 7.30 - 7.80 and dissolved oxygen concentrations was more than 6 ppm. The analytical results of TM in the test s olution showed that the actual concentrations were found to be equivalent to the nominal soon after introduction of the solution. Subsequently, the test concentrations decreased to about 70%, (killifish) and 80% (carp) of the initial concentrations during the 24 hr renewal. On average, measured concentrations for carp and medaka were 92.8% and 88.2% of the nominal, respectively. The 96 -h LC 50 values for carp and medaka are 2.1 and 3.0 mg ai/L, respectively, which exceed the reported solubility of TM in w ater (0.7 - 1.0 mg/L). Sublethal effects (loss of equilibrium, abnormal respiration lethargy, darkened color) were observed at 0.18 ppm and above for carp and 0.32 ppm and above for medaka. No precipitate was reported in test solutions, however, a non - stan dard solvent was used (10 parts dimethylsulfoxide and 10 parts polyoxyethylene hydrogenated castor oil) at a concentration (0.15 ml/L) that exceeded the recommended 0.1 ml/L level. This study is considered supplemental because of a number of deficiencies including: frequency of temperature determination was not indicated, the lighting schedule was not specified, aeration was not specified, the solvent was not one of those normally accepted; however, there was no mortality in the solvent control. **00156119** Takimoto et al (1981) exposed guppy ( Poecilia reticulata , avg. weight 40.4 mg) to TM TGAI (99.8%) in a 24 -h static renewal system for 96 -hours. Exposure concentrations were 1.0, 1.8, 5.6, 7.8, 10, 13.5, and 18 mg ai/L. Fish were acclimated 30 days and fas ted 24 hours prior to testing. Test temperature was 23C, pH was in the range of 7.4 to 7.8, and dissolved oxygen concentrations were 7.0 ppm and greater. Test concentration was measured only in the 1.0 ppm treatment., which averaged 95.8% of nominal. The 96 -hour LC 50 is estimated to be 3.18 ppb and the observed NOAEC is estimated to be 1.0 mg/L based on lack of mortality. No problems with solubility were reported in this study, however, a non - standard solvent was used (10 parts dimethylsulfoxide and 10 parts polyoxyethylene hydrogenated castor oil) at a concentration (0.36 ml/L) that exceeded the recommended 0.1 ml/L level. This study is classified as supplemental due to no reported data on temperature range and photoperiod, no total residual chlorine measurement of dilution water (dechlorinated tap water), no specification of treatments in which sublethal effects occurred.**131**

**41400301** McAllister (1989) exposed juvenile bluegill ( Lepomis macrochirus, 3.4 + 0.94g) to TM (97.2%) in a flow through system (10. 7 overturns/day) for 96 hours. Bluegill were reared for 6 months and not fed 48 hours prior to testing (no mortality during this period). Temperature was maintained at 22 + 1°C and dilution water used in the test was a soft blended water (a mixture of we ll water and reverse - osmosis well water). Nominal test concentrations were 46, 93, 185, 370, and 740 ug ai//L) plus a negative and solvent control (0.1 ml/L acetone). During the test, dissolved oxygen ranged from 87 to 94% saturation, pH ranged from 7.7 - 8. 0 and temperature ranged from 21.5 - 21.8C. The mean measured concentrations were 43, 93, 179, 360 and 720 u g/L, representing 93, 100, 97, 97, and 97% of the nominal concentrations, respectively. No mortality occurred during the observation periods. The 24 - , 48 - , 72 - , and 96 -hour LC 50 values were all estimated to be >720 u g/L, based on the mean measured concentrations at 0 and 96 hours. The no observed - effect concentration (NOEC) was determined to be 720 u g/L. This study is considered supplemental becaus e an LC 50 was not achieved and a precipitate was observed at highest test treatment every day but samples were not apparently centrifuged. **48341932** Palmer et al (2010) conducted a static renewal 96 -h acute toxicity study of sheepshead minnow, Cyprinodon variegatus , using TM TGAI (95.6%) at nominal concentrations of 0 (negative and solvent controls), 63, 125, 250, 500, and 1,000 μg ai/L. The mean - measured concentrations were <LOQ (<30, controls), 50, 89, 183, 372, and 312 μg ai/L. Precipitation was repor ted at the highest test concentration and therefore, results were centrifuged prior to analysis. No mortality or sublethal effects occurred at any test concentration, resulting in a 96 -h LC 50 of >372 μg ai/L. The NOAEC value, based on a lack of mortal ity and sub - lethal effects, was 372 μg ai/L. Based on the results of this study, Tolclofos - methyl would be classified as not toxic at the limit of its water solubility to Cyprinodon variegatus. **Fish, Chronic Toxicity 42106501**  Cohle and Leak (1991) condu cted a 97 - day chronic early life stage test on rainbow trout, O. mykiss using flow through condition. Thirty - five eggs were randomly placed in each of 4 incubation cups/treatment with hard blended dilution water. Viability was determined on dilution water controls. Endpoints measured included mortality, hatching, fry mortality, growth and behavioral changes. The temperature, dissolved oxygen (DO), conductivity and pH were measured weekly and on days 0**,** 1, and 97. Dissolved oxygen ranged from 8.1 to 10.8 mg/l (75 to 100% saturation at test temperatures), pH values ranged from 8.0 to 8.7, conductivity ranged from 373 to 445, umhos/cm, alkalinity and hardness ranged from 178 to 200 mg/l and 158 to 178 mg/l , respectively. With the exception of days 36 and 82 - 87, the temperature ranged from 8.6 to 11.2C. On these days, cooling system failure resulted in gradual temperature fluctuations outside this range (7.9 - 13.6C) which did not appear to affect the integrity of the test. The mean measured concentrations for the 97 - day test were 12, 28, 53, 110, and 200 ug/l. These values represent 92, 122, 106, 110, and 100% of nominal concentrations. The viability of the eggs held in control water was 100%. Hatching began on day 32 and was 95% complete by day 37. Percen t egg, hatch in all replicates of the controls was 100% and no significant reduction in percent egg hatch was detected for any test level compared to the controls. The number of fry swimming -up in each chamber was recorded for days 49 through 59. Although initially swim -up progressed somewhat slower in 28 ug/l and 53 ug/l compared to controls, only in 110 ug/l and 200 ug/l did there appear to be a biologically significant delay in swim-up. Fry survival at 37 - d post hatch was significantly reduced at the highest test concentration**132**

(200 ug/l). At test termination (60 days post hatch), fry survival in the two highest concentrations (110 and 200 ug/l) was significantly lower than the controls. At 37 days post -hatch, significant reductions in fish lengths were observed at 12, 28, 53, 110 ug/l relative to negative controls.. Significant reductions in fish weight were observed at all test concentrations at 60 - d post hatch. For fish weight (60d post hatch), the LOAEC represents a 24% reduction relative to negative controls, while the length LOAEC represents a 1.3% reduction relative to negative controls. The NOAEC for this study is determined to be < 12 ug ai/L and the LOAEC determined to be 12 ug ai/L. This study is classified as supplemental because a definitiv e NOAEC was not achieved. **Invertebrates, Acute Toxicity 43528001**  Murrell et al (1994) exposed < 24h old Daphnia magna to TM (98.8%) for 48 hours in a static test system. Ten daphnids were exposed to a series of 5 test concentrations (plus solvent and ne gative controls) in each of 2 replicate containers. Mean measured concentrations were 8.4, 17, 26, 41, and 64 mg ai/L and averaged 65% of nominal). Concentrations were stable from 0 to 48 hours. Immobility was 0% at 26 mg ai/L and below. At 41 and 64 mg ai/L, 25% and 90% immobility occurred after 48 hours. A 48 -h EC 50 of 48 mg ai/L was determined from this test, which is over two orders of magnitude above the solubility of TM. This study is considered supplemental because solvent concentrations of 1.06 ml/L exceeded the limit of 0.1 ml/L and surface films were observed in all test vessels at > 17 ppm mean measured concentration at 48 ppm without centrifugation prior to analysis. **00156120** Takimoto and Kagoshima (1982) exposed D. pulex to 1.0, 1.8, 5.6, 7.8, and 10 mg ai/LTM (99.8%) in a static system for 24 hours. Twenty daphnids were exposed/treatment among 4 replicate s. Concentrations were not measured in this study. No immobilization occurred at 1.0 mg ai/L, but 20%, 80%, 100%, 100% and 100% immobilization occurred at 1.8, 5.6, 7.8 and 10 mg ai/L, respectively. No precipitate was reported in test solutions, however , a non - standard solvent was used (10 parts dimethylsulfoxide and 10 parts polyoxyethylene hydrogenated castor oil) at a concentration (0.15 ml/L) that exceeded the recommended 0.1 ml/L level. This study is classified as supplemental because the test dura tion was less than recommended in guidelines and test concentrations were not measured. Furthermore, no reported data on temperature range and photoperiod and no total residual chlorine measurement of dilution water (dechlorinated tap water) **47837501** Dionne, E. (1998) exposed 20 D. magna (< 24h) to DM - TM (a degradate of TM) in a static system over a period of 48 hours (five daphnia/replicate). Nominal concentrations were 16, 27, 45, 75 and 125 mg a.i./L. In addition, a dilution water control was tested (solvents were not used so a solvent control was not necessary). For analytical verification of the test item, samples were taken at 0 and 48 hours from all concentrations. QA spike results indicate recovery of 96% to 104% respectively using high performance liquid chromatographic with ultraviolet detection (HPLC/UV) procedure. Immobilization and signs of toxicity were assessed daily. Temperature, pH and dissolved oxygen concentrations were also measured daily. Alkalinity, hardness, and conductivity were measured in a sample of the dilution water at test initiation. The test substance was stable over 48 hours although measure concentrations were 67

– 76% of nominal. Regulatory endpoints are reported as mean measured concentrations. All water quality parameters remained within acceptable limits. Test solutions were observed to be clear and colorless throughout the exposure period. Following 48 hours of exposure (test termination), no immobilization or adverse effects**133**

were observed among daphnids exposed to any treatment level tested or the control. Based on these results, the 48 -hour EC 50 was empirically estimated to be greater than 95 mg a.i./L, the highest concentration tested. The NOAEC was determined to be 95 mg a.i./L. This study is considered acceptable. **48341929** Saltwater mysids (

Americamysis bahia ) <24 hours old were exposed to nominal concentrations of 63, 125, 250, 500 and 1000 ug ai/L, a negative control (dilution water), and a solvent control (0.1 mL/L dimethylformamide) for 96 hours under static -renewal conditions (Palmer et al 2010). Two replicate test chambers were maintained in each treatment and control group, with 10 mysids in each test chamber, for a total of 20 mysids per concentration White precipitate was observed on the solution surface of the 1000 ug a.i./L nominal test concentration at preparation. Therefore, the 1000 ug a.i./L solutions were filtered through a glass microfiber filter. No precipitate or visual evidence of insoluble material was noted in any of the test chambers. Mean measured test concentrations for this study were 60, 121, 230, 458 and 742 ug a.i./L, representing 95, 97, 92, 92 and 74% of nominal concentrations. There was 10% (one animal in each replicate) mortality among the mysids in the negative control group. All other mysids in the negative control and solvent control groups appeared normal throughout the test. A single mortality occurred in the 60 ug a.i/L treatment group, but it was deemed not treatment related due to the absence of mortality and signs of toxic ity in the next higher treatment group. All remaining mysids in the 60 and 121 ug a.i./L treatment groups appeared normal throughout the test, with no mortalities or overt signs of toxicity observed. Percent mortality in the 230, 458 and 742 ug a.i./L trea tment groups at test termination was 15,65 and 100%, respectively. Surviving mysids in the 458 ug a.i./L treatment group appeared small in comparison to control organisms. The 96 -h LC 50 is 327 ug ai/L and the NOAEC is 121 ug ai/L. This study is considered acceptable and classifies TM as highly toxic to saltwater invertebrates. **48341928** Gallagher et al (2010) exposed Eastern oysters ( Crassostrea virginica ) in natural seawater to a geometric series of five test concentrations, a negative control (dilution water) and a solvent control (0.1 mL/L HPLC - grade dimethylformamide) for 96 hours under flow - through conditions. Prior to use, the 20 ppt seawater was filtered to 0.45 um to remove fine particles. One test chamber was maintained in each treatment and control group with 20 eastern oysters in each test chamber. Nominal test concentrations selected were 0.038, 0.075, 0.15, 030, and 0.60 mg ai/L. Just prior to initiation, recently deposited shell was removed by grinding the periphery of the oysters. The oysters then were indiscriminately assigned to exposure chambers at test initiation. Observations of mortality and other signs of toxicity were made approximately 5, 24, 48, 72 and 96 hours (±1 hour) after test initiation, and shell deposition was measured at 9 6 hours. Mean measured test concentrations for this study were 0.036, 0.070, 0.14, 0.28, and 0.54 mg a.i./L, and represent 95, 93, 93, 93 and 90% of nominal concentrations, respectively. A slight precipitate was observed in the highest treatment (0.60 mg ai/L nominal), and centrifugation confirmed that 72% of test substance was in solution. No precipitates were observed other test concentrations. All oysters appeared normal throughout the 96 -hour exposure period and no mortalities occurred. Mean shell deposition in the 0.036, 0.070, 0.14, 0.28 and 0.54 mg a.i./L treatment groups was - 18.4, 14.8, 21.8, 64.3 and 85.2%, respectively, relative to pooled controls. The 96 -hour EC50 was calculated to be 0.22 mg a.i./L, with a 95% confidence interval of 0.18 to 0.29 mg a.i./L. The NOAEC was 0.14 mg a.i./L.**134**

**Invertebrate, Chronic Toxicity 41400303**  Burgess (1989) conducted a freshwater invertebrate ( D. magna ) lifecycle test with TM TGAI (97.6%) Forty daphnids (10/rep.) were exposed throughout their life cycle to mean - measured concentrations of TM of 0.026, 0.062, 0.089, 0.19, and 0.39 mg ai/L, representing 108, 129, 89, 95, and 98% of the nominal values, resp ectively. Survival was significantly different between the pooled controls and the mean measured exposure levels 0.19 and 0.39 mg/L. The mean young/adult reproduction day after 21 days was significantly greater in the solvent control (4.7 young/adult reproduction day) compared to the negative control (3.8 young/adult reproduction day). Therefore, the original analysis of the data compared results to the solvent control, which indicated significant effects at mean - measured concentrations of 0.062, 0.089, and 0.19 mg ai/L. Based on reproductive effects, the NOAEC and LOAEC are estimated at 0.026 and 0.062 mg ai/L. respectively. Raw data were not provided in the study report from which to recalculate the endpoints according to comparisons to negative contro ls (current EFED policy). However, the apparent solvent effect resulted in an increase in reproduction and the LOAEC (3.2 young/reproduction day at 0.062 ug ai/L) still represents a 15% reduction relative to the negative controls (3.8 young/reproduction day). Therefore, it is reasonable to consider the effects at 0.062 mg ai/L biologically significant even if recalculation resulted in no statistically significant difference relative to negative controls. This study is classified as supplemental because raw data on reproduction were not included in the study report). **48341933** Four replicate chambers containing 15 mysids each were exposed to a geometric series of five test concentrations, a negative control (dilution water) and a solvent control (0.1 mL/L dimethyl - formamide) under flow - through conditions for 38 days (Palmer et al 2009). The mean measured test concentrations for this study were 3.9, 8.2, 17, 35 and 63 ug a.i./L, representing 70, 75, 74, 78 and 70% of nominal concentrations, respectively. No precipitates or visual evidence of insoluble material was observed in any control or treatment solution. On Day 15 of the test, after mysids attained sexual maturity, male and female adults were paired in each treatment and control group, with a maximum of five reproductive pairs per replicate. No treatment related effects were observed on mysid survival (mean measured NOAEC = 63 ug ai/L). The overall survival of first generation control mysids (negative and solvent controls combined) over the entire exposure period was 73.3%, which is above the acceptance criteria of >70% survival (although solvent control survival was slightly below at 68.3%). Time to first brood was unusually long in controls and all treatments (mean occurring > 27days), which may have resulted in extension of the test duration from the usual 28 to 38 days. Male and female total length were significantly reduced by ~5% relative negative controls at 35 ug ai/L. Significant reductions in dry weight relative to the negative control occurred at 63 ug ai/L (females; 30% reduced) and 35 ug ai/L (males, 27% reduced). The mean number of young produced per female in the negative and solvent controls was 4.4 and 4.3, respectively and was sufficient to evaluate reproductive effects according to ASTM guidelines. A statistically significant treatment related effect on # young/reproductive day was observed at 63 ug ai/L; However, the study demonstrated exceptionally poor statistical power due to high variability within treatments in this endpoint ( MDD =107% relative to negative controls). Based on a 50% reduction in # young/reproductive day at 8.2 ug ai/L, the statistically-based endpoint was considered to be unreliable and inferred a biologically significant NOAEC at 3.9 ug ai/L. This study is con sidered supplemental due to the low statistical power associated with the reproductive endpoints and unusually long time required for first brood resulting in an extension of the test duration by 10 days.**135**

**Benthic Invertebrate Toxicity 48341931**  Thomas et al (2010) exposed amphipods to a geometric series of five test concentrations of TM TGAI (95.6%), a solvent control and a negative control for 10 days under flow - through test conditions. Eight replicate test compartments were maintained in each treatment and control group, with 10 amphipods in each test compartment, for a total of 80 amphipods per test concentration. An additional two replicates were added in each treatment and control group for analytical sampling of sediment, pore water and overlying wat er. Nominal test concentrations were 6.3, 13, 25, 50 and 100 mg a.i./kg sediment dry weight. Formulated sediment (81% sand, 8% silt, and 11% clay; 2.5% total organic carbon and moderately -hard well water freshwater were used in this study. Temperature was 23 + 1C during the study, dissolved oxygen concentrations in overlying water were > 80% (6.8 mg/L) of saturation and pH ranged from 8.3 to 8.5. Am phipods were fed 1.0 mL of YCT. The mean measured test concentrations were 4.8, 12, 24, 48 and 103 mg a.i./kg. from the 6.3, 13, 25, 50 and 100 mg a.i./kg treatment groups, respectively. Mean percent survival after 10 days was 86, 93, 89, 90, 85, 80, and 95% for the negative control, solvent control, and mean - measured 4.8, 12, 24, 48, and 103 mg ai/kg sediment levels, respectively. The 10 - day LC 50 was >103 mg ai/kg, and the NOAEC for survival was 103 mg ai/kg. This study is considered acceptable. **48341935** During the initial study, groups of amphipods ( Leptocheirus plumulosus ) were exposed to a geometric seri es of five test concentrations, a solvent control and a negative control for 10 days under static test conditions. During the continuation study, groups of amphipods were exposed to a geometric series of three test concentrations, a solvent control and a n egative control for 10 days under static conditions. Five replicate test chambers were maintained in each treatment and control group, with 20 amphipods in each test chamber, for a total of 100 amphipods per test concentration. Nominal definitive test conc entrations were 6.3, 13, 25, 50 and 100 mg a.i/kg of sediment based on the dry weight of the sediment. The nominal concentrations for the continuation study were 0.78, 1.6 and 3.1 mg a.i./kg. Samples of the sediment used in both the initial trial and the c ontinuation study were determined to have an organic carbon content of 2.4 and 2.8%, respectively. The mean measured concentrations (day 0 and day 10) for the 6.3, 13, 25, 50 and 100 mg a.i./kg treatment groups were 5.3, 11, 23, 48 and 97 mg a.i./kg. The mean measured concentrations (day 0 and 10) for the 0.78, 1.6and3.1 mg a.i/kg treatment groups were 0.45, 1.1 and 2.1 mg a.i./kg. The mean survival of Leptocheirus in the negative control, solvent control, 5.3, 11, 23, 48 and 97 mg a.i./kg treatment groups were 96, 98, 61, 33, 18, 17 and 0%, respectively, at test termination. The mean percent survival of Leptocheirus in the negative control, solvent control, 0.45, 1.1, 2.1, mg a.i./kg treatment groups were 96, 95, 89, 96 and 95%, respectively and were not s ignificantly different. The results of the definitive test and the continuation study were combined for the determination of the NOEC (2.1 mg ai/kg sediment), LOAEC (5.3 ug ai/kg sediment) and LC 50 (7.05 mg a.i./kg sediment). This study is considered sup plemental because the NOAEC and LOAEC were derived from separate studies. Therefore, there is some uncertainty regarding the possible effect of different batches of organisms on the relationship between the unbounded LOAEC from the first study and the unb ounded NOAEC from the second study. Given that both studies were conducted in the same lab over very similar time periods with the same sediment and organism source, these endpoints are still considered scientifically valid and useful for risk assessment. **48737504** Putt (2002) conducted a 28 - d chronic sediment toxicity test of the freshwater midge, Chironomus riparius,**136**

according to OECD 219 protocol (spiked water). Twenty, 1 st instar midge (3 - days post hatch) were added to each of 8 replicate test chamb ers (4 for biological measurements, 4 for chemical measurements) with gentle aeration. Prior to organisms addition, field - collected test sediments (2.4% TOC, 94% sand, 6% silt, 0% clay) and overlying water (soft well water) were condition in test vessels for 7 days. Temperature was 19 - 21C, dissolved oxygen was >7.9 mg/L and pH in overlying water ranged from 5.5 - 7.7. Midge larvae were fed finely ground fish flake food daily during the test. Measured concentrations of total [ 14 C] at 1 -hour in the 0.063, 0.13, 0.25, 0.50 and 1.0 mg a.i./L treatment levels were 0.064, 0.13, 0.23, 0.47 and 0.76 mg a.i./L, respectively. Total [ 14 C] concentrations decreased dramatically by day 7 and were generally less than 20% of the targeted [ 14 C] concentration in the overlying water for the remainder of the exposure. Measured concentrations of total [ 14 C] at 1 -hour in the 0.063, 0.25 and 1.0 mg a.i./L treatment levels were 0.00037, 0.00068 and 0.0057 mg a.i./L, respectively. The total [ 14 C] in pore water increased by more than 10 - fold during the exposure. On test day 28 (test termination), measured concentrations of total [ 14 C] in the 0.063, 0.25 and 1.0 mg a.i./L treatment levels were 0.0048, 0.019 and 0.16 mg a.i./L, respectively. Measured concentrations of tolclofos - methyl at 1 - hour in the 0.063, 0.13, 0.25, 0.50 and 1.0 mg a.i./L treatment levels were 0.020, 0.024, 0.063, 0.10 and 0.26 mg a.i./kg, respectively. Total [[ 14 C] concentrations in the sediments had generally increased 5 - fold by day 7. Total [ 14 C] sedime nt concentrations then increased slightly or decreased slightly throughout the remainder of the study. These results are consistent with the expected partitioning of TM from the overlying water into the sediments and pore water. Results indicate development rate was significantly reduced by 3.4% relative to negative controls at 0.188 mg ai/L porewater (mean measured), resulting in a NOAEC of 0.013 mg ai/L pore water (0.186 mg ai/kg dw in sediment, 7.7 mg ai/kg - OC). Mean percent emergence in test treatment s (79 - 86%) was not affected at any test concentration relative to controls (86%). Reproductive endpoints were not included in this study, per OECD guidelines. However, a full life cycle test using spiked sediments with measurement of reproduction is required per USEPA pesticide registration for TM. Therefore, this study is considered supplemental. **Aquatic Plant Toxicity 48737506**  The toxicity of TM TGAI (97.8%) to the freshwater green alga, Scenedesmus subspicatus, was investigated according to OECD Gui deline #201 (Sayers 2003). After the test solutions (TM added to AAP medium) were added to the test flasks (100 ml per flask), a 0.730 - ml inoculum of S. subspicatus cells (cell density of approximately 137 x 10 4 cells/m), was aseptically introduced into e ach flask. This inoculum provided the required initial (0 hour) cell density of approximately1.0 x 104 cells/ml. During the 72 -h exposure, temperature ranged from 23 to 24°C, continuous illumination was provided at 7000 to 8900 lux (650 to 825 foot candles ), and a shaking rate of 100 rpm was applied. Due to the limited solubility of tolclofos - methyl (0.708 mg/L), the mean measured concentrations ranged from 53 to 97% (decreasing with increasing tolclofos - methyl concentration) and defined the treatment leve ls as 0.13, 0.22, 0.39, 0.69 and 1.1 mg a.i./L. Analysis of centrifuged samples indicated no impact of algae on test concentrations. The effect of TM on inhibition of total biomass (area under the growth curve) and average growth rate (u ave ) were evaluate d. Based on mean measured concentrations, the 72 -hr EC 50 value for total biomass was determined to be 0.78 mg ai/L with 95% confidence intervals of 0.62 to 0.92 mg ai/L. The 72 -h NOAEC was determined to be 0.18 mg a.i./L. This study is classified as sup plemental since OSCPP test guidelines (850.5400) require that a 96 -h study be conducted with aquatic algae.**137**

**48737505** Hoberg (1998) evaluated the effects of DM - TM (a degradate of TM) to freshwater green alga S. subspicatus in replicate 250 - mL flasks, three flasks (A, B and C) per treatment level and the controls. 0.35 - mL inoculum of algal cells, at a density of approximately 2.84 x 10 4 cells/mL, was aseptically introduced into each flask. This inoculum provided the required initial (0 hour) cell density of approximately 1.0 x 10 4 cells/mL. At each subsequent 24 -hour interval, cell counts were conducted on each replicate vessel of each treatment solution and the controls using a hemacytometer and compound microscope. The test substance was stable over 72 hour s although measure concentrations were 75 - 77% of nominal. Light intensity (4100 - 5000 lux) was slightly lower than OECD guideline (5000 lux) based on optimization with this laboratory/light source. Algae appeared to be on log growth phase throughout the t est. Cell density, biomass and growth rate were reduced by a maximum of 8.3, 8.6 and 1.3%, respectively, in the highest test concentration (97 mg DM - TM /L). As a result, EC50 values for all three endpoints were > 97 mg/L. NOAECs for cell density, biomas s and growth rate were 23, 12 and 23 mg DM - TM/L, respectively. The test generally conformed to OECD guidelines and no guideline deviations were reported by the study authors. However, for USEPA/OPP purposes, a 96h duration is required (850.5400). Therefore, this study is considered scientifically sound, but supplemental. **00156121** Takimoto and Ysutaniya (1983) evaluated the effects of TM TGAI (98.3%) on the green algae, Scenedesmus quadricauda, in triplicate 500ml flasks at dose levels of 0.01, 0.032, 0.1, 0.32, 1.0, 5.6 mg ai/L of Closterium medium according to OECD guideline #201. Test solutions were inoculated with a suspension of the algae (1x10 4 colonies/ml) at exponential growth phase along with a solvent control which contained 50 ul of added DMSO. Flasks were plugged with silicone, and incubated at 20±2°C with fluorescent light of about 5000 lux under shaking at 100 rpm. Test concentrations were not measured analytically. The significant reduction of biomass (p<0.05) was observed at 0.1 mg/1 and above on day 3 and later of incubation, however, these adverse effect did not inhibit biomass by 50%. The NOAEC (biomass) was determined to be 0.032 mg ai/L. The 7 - d EC50 was determined to be > 5.6 mg ai/L, which exceeds solubility of TM in water (0.7 - 1.0 mg ai/L). No information about the formation of precipitates (or lack thereof) was provided by the study authors. No significant reduction in growth rate (maximum or relative) was observed re lative to controls. Furthermore, no morphological abnormalities in algal cells were observed at any treatment during the test. This study is considered supplemental due to apparent lack of a negative control from which to evaluate the potential effect of the solvent on algae growth. **Avian Acute Oral Toxicity 00156112**  Roberts and Haskins (1981) evaluated the acute oral toxicity of TM TGAI (99.8%) to mallard duck ( Anas platyrhynchos) using a limit dose of 5000 mg ai/kg bw followed by a 14 - d observation period. After 15 hours fasting, 10 16 -week old mallard ducks were tested in controls (receiving just corn oil) and 20 were tested at the limit dose. Cage size or # organisms/cage was not specified. Temperature ranged from 13 - 26C and a natural daylight photop eriod was utilized. No mortalities in control or at the 5000 mg/kg test level. Weight changes were variable for all birds, but within normal limits. This study is classified as acceptable and results indicate that TM is practically non - toxic to the mallard duck on an acute, oral basis. **00156113** Roberts and Haskins (1982) evaluated the acute oral toxicity of TM TGAI (99.8%) to bobwhite quail**138**

( Colinus virginianus ) using a limit dose of 5000 mg ai/kg bw followed by a 14 - d observation period. After 15 hours f

asting, 10 16 - week old quail were tested in controls (receiving just corn oil) and 20 were tested at the limit dose. Five birds were housed per cage but cage size was not specified. Temperature ranged from 13 - 26C and a natural daylight photoperiod (17h daylight) was utilized. No mortalities in control or at the 5000 mg/kg test level. Weight changes were variable for all birds, but within normal limits. This study is classified as acceptable and results from this study indicate that TM is practically non - to xic to the bobwhite quail on an acute, oral basis. Roberts and Haskins (1981) also studied the acute oral toxicity of TM TGAI (99.8%) to ring necked pheasant (Phasianus colchicus) using a limit dose of 5000 mg ai/kg bw followed by a 14 - d observation perio d. After overnight hours fasting, 10 0.94 - 1.34 kg old pheasants were tested in controls (receiving just corn oil) and 20 were tested at the limit dose. Cage size and #birds/cage were not specified. Temperature ranged from 13 - 30C and a natural daylight pho toperiod (17h daylight) was utilized. Only one mortality occurred among the 20 test birds. This was not considered to be dose related. Body weights were variable, but considered within normal limits. The acute oral LD 50 is estimated to be > 5000 mg ai/kg b w. This study is classified as acceptable and results from this study indicate that TM is practically non - toxic to the pheasant on an acute, oral basis. **48341936** The acute oral toxicity of TM TGAI (95.6%) to zebra finches, Poephila guttata , was assessed over 14 days using a limit test design. TM was administered to the birds by a 14 gauge cannula at nominal doses of 0 (vehicle control), and 2000 mg ai/kg bw. There was no mortality in the control or the treatment group. There were no signs of toxicity/abnormal behaviors with the exception of regurgitation . Within the first hour of dosing, 2/12 birds (17%) at the 2000 mg ai/L dose regurgitated. The remaining 10 birds that did not regurgitate the test material were unremarkable. There were no significant reductions in % body weight gain for either males or females nor were there any clinical or behavioral signs of intoxication. Gross necropsies were not performed and were not necessary based on the lack of sublethal effects. The 14 - day acute oral LD 50 an d NOAEL were determined to be >2000 and 2000 mg ai/kg bw, respectively, based a lack of mortality, minimal abnormal behavior, and affected % body weight gain. According to the US EPA classification, TM would be classified as practically non - toxic to Poeph ila guttata on an acute oral basis. Although there was some regurgitation (2/20 birds), the frequency was low and does not impact interpretation of the study results (i.e., LD 50 is still > 5000 mg ai/kg bw). This toxicity study is classified as scientifica lly sound/acceptable and thus satisfies the guideline requirement for an acute oral avian toxicity study with a passerine species. **Avian Subacute Dietary Toxicity 00156115**  Beavers (1985) evaluated the dietary toxicity of TM TGAI (97.7%) to 10 - d old mallard duck ( A. platyrhynchos) fed a diet containing 0 (2% corn oil), 562, 1000, 1780, 3160 and 5620 ppm TM. Ten ducks were tested per treatment in cages (72 cm x 90 cm L x 24 cm H) during a 5 - d exposure and a 3 - d observation period. Temperature was 81 F (+/ - 2F), photoperiod was 17 hours, and humidity was 57%. No mortalities occurred, therefore, the dietary LC 50 is greater than 5620 ppm. Food consumption and weight gain were similar at all test levels. This study is classified as acceptable and result s indicate that TM is practically non - toxic to the mallard duck on an subacute, dietary basis. **00156116** Beavers (1985) evaluated the dietary toxicity of TM TGAI (97.7%) to 12 - d old bobwhite quail ( C.**139**

virginianus ) fed a diet containing 0 (2% corn oil), 562, 1000, 1780, 3160 and 5620 ppm TM. Ten quail were tested per treatment in cages (72 cm x 90 cm L x 24 cm H) during a 5 - d exposure and a 3 - d observation period. Controls contained 50 quail. Temperature was 100 F (+/ - 2F), photoperiod was 17 hours, and humidity was 57 A total of 6 birds (out of 50) in the controls died (12%). This was attributed to aggression as was evidenced by toe -picking. There was 20% mortality (2 of 10) at the 1000 ppm level. One occurred at 4 days, the second at six days. The study author indicated the mortalities did not appear to be dose related, since no mortalities occurred at higher levels. There was no apparent effect on body weight or feed consumption. This study is classified as acc eptable and results indicate that TM is practically non - toxic to the mallard duck on a subacute, dietary basis. **Avian Chronic Toxicity 40190202**  Beavers et al (1987) evaluated the chronic dietary toxicity of TM (97.7%) on 41 week old mallard ducks. Three groups, 16 replicates (pairs) per group, of pen -reared mallard ducks approaching their first breeding season were fed a diet containing 500, 2500 or 7500 ppm of TM. A fourth group was fed a control diet containing 0.09% corn oil, the amount used as a carrier for the test material. No treatment related mortalities or overt signs of toxicity occurred at 500 ppm. At 2500 ppm, 3 of the 32 adults died; and at 7500, 10 died. At both 2500 and 7500, lower limb weakness and other toxic symptoms were observed. Analy sis of variance indicates that at 2500 ppm, statistically significant reductions were observed in number of eggs laid, eggs set, viable embryos, eggs hatched. This study is classified as acceptable. **40190201** Beavers and Jaber (1987) ) evaluated the chronic dietary toxicity of TM (97.7%) on 22 week old bobwhite quail. Three groups, 16 replicates (pairs) per group, of pen -reared bobwhite quail approaching their first breeding season were fed a diet containing 500, 2500 or 7500 ppm of TM. A fourth group was fed a control diet containing 0.09% corn oil, the amount used as a carrier for the test material. No treatment related mortalities or overt signs of toxicity occurred. Five adults mortalities occurred, none of which appeared to be treatment related. There were no statistically significant differences in adult body weight of males between control and any treatment groups. Females, at 7500 ppm exhibited a slight, but statistically significant reduction of body weight during week 7. Feed consumption appears to have been reduced at the 7500 ppm level. There was no apparent effect on treatment parameters or sublethal effects at the 500 ppm concentration. When compared to the control group, there was a significant reduction in the number of eggs laid in both the 2500 and 7500 ppm concentrations. The reduction in number of eggs laid continued to result in a reduced number of eggs set, viable embryos, live embryos and eggs hatched at the 2500 and 7500 ppm levels. There was no apparent effect on cracked eggs. This study is classified as acceptable, and the NOEL for TM is 500 ppm. **Mammals, Acute Toxicity 00156128**  Segawa et al (1978) evaluated the acute oral toxicity of TM (97%) to the rat, (Rattus norvegicus) and the mouse ( Mus musculus) . Ten male and female Spragu e - Dawley rats approximately 7 weeks old and weighing 200 to 260 g (males) or 170 to 210 g (females) and 10 male and female mice (7 weeks old) weighing 20 to 24 g (males) or 18 to 20 g (females), were used in these studies. TM was dissolved in corn oil and administered to 10 rats/dose level/sex and 10 mice/dose level/sex (gavage) in concentrations: 1000, 2500, 3750 and 5000 mg/kg bw (rats) and 1000, 1500, 2000, 3000, 4000 mg/kg (mice). The animals were kept in a room with a temperature of 23 + 1 °C and with a relative humidity of 60 + 5 percent. Food (CE - 2 type) and water were available ad libitum. All animals were observed daily for signs**140**

of toxicity/mortality. Rats (both sexes) receiving the dose levels of 3750 or 5000 mg/kg developed a variety of toxic sy mptoms which included: irregular respiration, dyspnea, piloerection, decreased motor activity, and ataxia of the hind limb or whole body, 3 to 4 hours post - administration. Mortality was observed only in the high dose tested (5000 mg/kg) in both sexes of ra ts and total mortality reached 5/10 (or 50%) in male rats and 6/10 (or 60%) in female rats by the end of the 14 - day observation period. All toxic signs disappeared from surviving animals 3 to 8 days postadministration. The acute oral LD50 for male rats was calculated to be 4900 mg/kg bw using the binomial method Mice (male and female) receiving 1500 mg/kg or higher developed the same toxic symptoms as those reported for rats. Maximum mortality occurred at the highest test concentration (4000 mg ai/kg b w) resulting in an LD 50 of 3500 mg ai/kg bw. Both the rat and mouse studies are classified as acceptable and indicate that TM is practically non - toxic (rat) and slightly toxic (mouse) on an acute oral basis. **00156124** Kynoch (1985) studied the acute oral toxicity of TM to male and female HC/CFY Remote Sprague Dawley rats. Animals (4 to 6 weeks old and weighed 100 to 135 g) were acclimated for at least 7days to experimental conditions prior to testing. For the main study, five male and five female rats were treated with 5 g TM /kg bodyweight. All animals were housed in metal cages separately for each sex, identified by cage number and ear punching, and kept in an animal room with a temperature of 21 to 22°C, relative humidity of 55 percent, approximately 1 5 air changes/hour, and a l2 -hour light/ dark cycle. The animals had free access to food (rodent diet - Labsure LAD I) and water throughout the study. Food was withheld from all test animals approximately 12 hours prior to and 4 hours after dosing. Animals w ere observed for 14 days for signs of toxicity and/or mortality. Body weights were recorded on days 1, 8, or 15 on study. At sacrifice (day 15) all animals were examined macroscopically. The single high - dose level (5 g/kg) tested in the main study did not result in mortality of the male or female rats. Clinical signs of toxicity were observed in all animals tested and included piloerection and hunched posture shortly after dosing with complete recovery in 5 days. Body weight gains were observed in all test animals of the main study and at sacrifice none of these animals had any abnormal macroscopic lesions. Thus, the acute oral LD 50 for male and female rats was higher than 5 g/kg, indicating TM is practically non - toxic to the rat on an acute oral basis. This study is classified as acceptable. **Mammals, chronic and subchronic toxicity 41422901**  Morseth (1987) assessed the developmental toxicity of TM when administered by gavage to rats on gestation days 6 through 15, inclusive. Doses were 0 100, 300, and 100 0 mg /kg bw/d. No clinical signs were noted during the twice daily cage - side observations., There was a non - significant dose -related decrease in corrected body weight gains during the dosing period and during the entire gestation period, when compared to t

he controls. The only finding of statistical significance was unossified 6 th sternebra, at the 1,000 mg/kg/day group, when compared to the controls. No fetal deaths were reported in any of the groups. There were no external variations observed The NOAEL from this study is 300 mg ai/kg bw/d. **00156138** Pence et al (1979) studied the effect of TM on beagle dogs via dietary exposure. Animals were 5 - 7 months old at testing and ranged in weight from 6.7 to 12.4 kg (males) and 5.8 to 10.2 kg (females). Six male and female dogs were tested per dose. TM was administered in the diet at concentrations of 0, 200,**141**

600, and 2000 ppm for 6 months. Toxic effects observed at 2000 ppm included reduced body weight gain, hematocrit, hemoglobin, and erythrocyte count in both sexes. Alkaline phosphatase and absolute and re lative liver weights were increased in both sexes. Plasma cholinesterase was significantly reduced in high dose females at all report periods. These data support a NOEL of 600 ppm. **00156137** Suzuki et al. (1978) evaluated the effect of 9 months exposure t o TM in the diet on mice. Mice were exposed to 0, 10, 30, 100 and 3000 ppm TM (1.20, 3.78, 12.20, 513 mg/kg/day for males and 1.42, 4.14, 13.80, and 564 mg/kg/ day for females respectively). Both body weight and body weight gain were reduced in the highes t dosage group (3000 ppm) of both sexes, although food consumption was increased in these groups. The NOAEL (body weight/weight gain) is 100 ppm. The only other significant toxicity observed in this study was plasma cholinesterase inhibition in female mice at doses of 30 ppm and above. The study is classified as supplementary because the analysis for concentration, homogeneity, and stability of the test compound in the diet was not submitted with the study. **Toxicity to Honeybee 41794202**  Winter et al (199 0) evaluated the acute contact toxicity of TM (97.7%) to young adult honeybees ( Apis mellifera ). All test bees were 1 to 4 days old at initiation of the study and were apparently healthy. On the day of study initiation, all bees that had emerged were immo bilized with N 2 and at least 25 bees were placed into each test chamber containing 50% sugar solution. The photoperiod was eight hours of light per day. Ambient temperatures in the test room at the time of observations ranged from 22 to 23 C. Five treatment levels, 13, 22, 36, 60, and 100 ug/bee, were tested along with a solvent control and a negative control. Two replicates were tested at each dosage, with 25 bees per replicate. The solvent control bees received a volume of acetone equal to the largest volume used during the test. The study authors found that TM was practically nontoxic to honey bees, with an LD50 greater than 100 ug per bee. This study is classified as acceptable. **00163557** A second study was conducted on the toxicity of TM to honeybees ( A. mellifera ) on an acute contact basis. TM was diluted with acetone and topically applied on the dorsal thorax of bees at the ratio of 1 ug per bee. The treated bees were kept in a polyethylene cup with food. Thirty bees were used for each dose. Mortality was observed 24 hours after treatment. The study authors found that tolclofos - methyl was relatively nontoxic to honey bees, with an > 100 ug per bee. There were a number of deficiencies in the study report (e.g., environmental conditions during test, typ e of food provided, and method used to immobilize test bees, etc.). Also, the test was run for 24 hours instead of the recommended 48hours. This study is classified as supplemental.**142**



## A **PPENDIX** 

## E **. R** **ISK** 

## Q **UOTIENT** 

## M **ETHOD AND** 

## L **EVELS OF** 

## C **ONCERN** The Risk Quotie nt Method is the means used by the Office of Pesticide Programs (OPP), Environmental Fate and Effects Division (EFED) integrate s the results of exposure and ecotoxicity data. For this method, Risk Quotients (RQs) are calculated by dividing exposure estimates by the acute and chronic ecotoxicity values ( i.e. , RQ = EXPOSURE/TOXICITY). These RQs are then compared to OPP's levels of concern (LOCs) (see **Table E**  **.1** ) . These LOCs are criteria used by OPP to indicate potential risk to non - target organisms and the n eed to consider regulatory action. EFED has defined LOCs for acute risk, potential restricted use classification, and for endangered species. The criteria indicate that a pesticide used as directed has the potential to cause adverse effects on non - target organisms. LOCs currently address the following risk presumption categories: (1) **Acute** - there is a potential for acute risk; regulatory action may be warranted in addition to restricted use classification; (2) **Acute restricted use** - the potential for acut e risk is high, but this may be mitigated through restricted use classification; (3) **Acute endangered species**

– the re is a potential for acute ri sk to endangered species , regulatory action may be warranted; and (4) **Chronic risk**

– the re is a po tential for chronic risk , regulatory action may be warranted. **Table E**  **.1 . Level of concern (LOC) by risk presumption category (EPA, 2004).**  **Risk Presumption RQ**  **LOC Mammals and Birds**  Acute Risk a EEC b/LC 50 or LD 50/sqft c or LD 50/dayd 0.5 Acute Restricted Use e EEC/LC 50 or LD 50/sqft or LD 50/day (or LD 50 <50 mg/kg) 0.2 Acute Listed Species f EEC/LC 50 or LD 50/sqft or LD 50/day 0.1 Chronic Risk EEC/NOEC 1 **Terrestrial Invertebrates** Interim Acute Li sted Species **i** EEC j / LD 50 k 0.05

**Aquatic Animals** Acute Risk EEC g /LC 50 or EC 50 0.5 Acute Restricted Use EEC/LC 50 or EC 50 0.1 Acute Listed Species EEC/LC 50 or EC 50 0.05 Chronic Risk EEC/NOEC 1 **Terrestrial Plants and Terrestrial Plants in Semi -** **Aquatic Areas Plants** Acute Risk EEC/EC 25 1 Acute Listed Species EEC/EC 05 or NOEC 1**143**

**Table E**  **.1 . Level of concern (LOC) by risk presumption category (EPA, 2004).**  **Risk Presumption RQ**  **LOC Aquatic Plants**  Acute Risk EEC h/EC 50 1 Acute Listed Species EEC g /EC 05 or NOEC 1

aPotential for acute toxicity for receptor species if RQ > LOC (EPA, 2004). bEstimated environmental concentration (ppm) on avian/mammalian food items . cmg/ft2 dmg of toxicant consumed per day ePotential for acute toxicity for receptor species, even considering restricted use classification, if RQ > LOC (EPA, 2004). f Potential for acute toxicity for listed species of receptor species if RQ > LOC (EPA, 2004 ). g EEC = ppb or ppm in water h EEC = lbs a.i./A **i** Potential for acute toxicity for listed species of receptor species if RQ > LOC (EPA, 2007) . j Estimated environmental concentration (ppm) calculated by T - REX for small or large insects. k The toxicity value for terrestrial invertebrates is typically calculated by multiplying the lowest available acute contact LD 50 for honeybee s by 1 bee/0.128g (which is based on the weight of an adult honeybee ) to convert units to μg a.i./g of bee. **Literature Cited** U.S. EPA. 2004. U.S. Environmental Protection Agency. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs, U.S. Environmental Protection Agency: Endangered and Threatened Species Effects Determinations. Office of Prevention, Pesticide, and Toxic Substances. January 23. U.S. EPA. 200 7. U.S. Environmental Protection Agency. Interim Policy: Acute Endangered Species Level of Concern (LOC) for Terrestrial Invertebrates. Environmental Fate and Effects Division, Office of Pestici de Programs . Memorandum issued, May 15, 2007.**144**



## A **PPENDIX** 

## F **. O**  **UTPUT** 

## F **ROM** 

## T **- REX**  **M ODEL**  

## (**V** 

## 1.5) **1. Seed Treatm ent Rate for Root Vegetables and Cotton**  **Chemi cal**  **: Name of**  **seed treatment formul**  **ation:**

**Percent AI in**  **fo rmul**  **ation: 100%**  1 **9. 99**  **Tested Body Wei**  **ght (g) Av**  **ian LD50: 2000.00**  **12 2159**  **Smal l (20g)**  **Av ia**  **n repro. NOAEC:**  **500.00 2749**  **Medium (100g) 3883**  **Large (1000g) Mammalian LD50:**  **3500.00 20**  **3761 Smal**  **l (15g) Mammalian NOAEL:**  **100.00 3043**  **Medium (35g) 1316**  **Large (1000g) Smal**  **l (15g) 13.11**  **Medium (35g) 10.61**  **Large (1000g) 4.59** 

**Cr op**  **Maximum**

**Ap pl**  **ication Rat** **e Ma**  **ximum Seed**

**Ap plication R**  **ate Av**  **ian Nagy Dose Mammalian Nagy**  **Dose Av**  **ailable AI (lbs ai/A)**  **(mg ai/kg seed)**  **(mg ai/kg-bw/day) (mg**  **ai/kg-bw/day) (mg**  **ai ft-2) Sm**  **all** 123.45 103.35 **Me di**  **um** 70.40 71.43 **Large** 31.52 16.56

**Acute (# 1)**  **Acute (# 2) Chroni**  **c Ac**  **ut e (# 1)**  **Ac ute (# 2)**  **Chroni c**  **corn, all or unspeci**  **fied 0.06**  **0. 00**  **0.98 0.03**  **0.00 7.88**  **Acute (# 1)**  **Acute (# 2) Chroni**  **c Ac**  **ut e (# 1)**  **Ac ute (# 2)**  **Chroni c**  **corn, all or unspeci**  **fied 0.03**  **0. 00**  **0.98 0.02**  **0.00 6.73**  **Acute (# 1)**  **Acute (# 2) Chroni**  **c Ac**  **ut e (# 1)**  **Ac ute (# 2)**  **Chroni c**  **corn, all or unspeci**  **fied 0.01**  **0. 00**  **0.98 0.01**  **0.00 3.61**  **† Acute**  **R Q #1 =**  **(m g ai /k** **g-bw /day)** **/ LD50**

**Acute R** **Q #2 = mg a**  **i ft-2 /(LD50*bw** **) Avia**  **n Chronic RQ = mg kg-1 s**  **eed / N**  **OAE L**  **Mammalian C hronic RQ =**  **mg a .i./k** **g-bw /day / adjus**  **te d N**  **OAE L**  **Avian (1000 g) Ma**  **mmalian (1000 g) An**  **imal Siz e**  **corn, all or unspecified** 0.0162 487.79 0.17

**Cr op**  **Tol clofos methyl**  **Ri zol**  **ex Floable Fungi cide**  **Density of product (lbs/gal): Dat** **a inputs are in blue**

**Av ian (100 g)**  **Ma mmalian (35 g)**  **Av ian (20 g)**  **Ma mmalian (15 g)**  **Ri sk Quotients**  **† Endpoint** **s Ad**  **ju sted LD50**  **Si ze**  **cl ass for**  **adj usted LD50**  **Re ported** 

**Ad ju**  **sted NOAEL for Mammals 145** 

**2 . Seed Treatm**  **ent Rate for all other crops**  **Chemi cal**  **: Name of**  **seed treatment formul**  **ation:**

**Percent AI in**  **fo rmul**  **ation: 100%**  1 **9. 99**  **Tested Body Wei**  **ght (g) Av**  **ian LD50: 2000.00**  **12 2159.**  **27 Smal**  **l (20g) Av**  **ia n**  **repro. NOAEC: 500.00**  **2748. 86**  **Medium (100g) 3882.**  **87 Large (1000g)**  **Mammalian LD50: 3500.00**  **20 3760.**  **99 Smal**  **l (15g) Mammalian NOAEL:**  **100.00 3043.**  **05 Medium (35g)**  **1316. 21**  **Large (1000g) Smal**  **l (15g) 13.11**  **Medium (35g) 10.61**  **Large (1000g) 4.59** 

**Cr op**  **Maximum**

**Ap pl**  **ication Rat** **e Ma**  **ximum Seed**

**Ap plication R**  **ate Av**  **ian Nagy Dose Mammalian Nagy**  **Dose Av**  **ailable AI (lbs ai/A)**  **(mg ai/kg seed)**  **(mg ai/kg-bw/day) (mg**  **ai/kg-bw/day) (mg**  **ai ft-2) Sm**  **all** 24.69 20.67 **Me di**  **um** 14.08 14.29 **Large** 6.30 3.31

**Acute (# 1)**  **Acute (# 2) Chroni**  **c Ac**  **ut e (# 1)**  **Ac ute (# 2)**  **Chroni c**  **corn, all or unspeci**  **fied 0.01**  **0. 00**  **0.20 0.01**  **0.00 1.58**  **Acute (# 1)**  **Acute (# 2) Chroni**  **c Ac**  **ut e (# 1)**  **Ac ute (# 2)**  **Chroni c**  **corn, all or unspeci**  **fied 0.01**  **0. 00**  **0.20 0.00**  **0.00 1.35**  **Acute (# 1)**  **Acute (# 2) Chroni**  **c Ac**  **ut e (# 1)**  **Ac ute (# 2)**  **Chroni c**  **corn, all or unspeci**  **fied 0.00**  **0. 00**  **0.20 0.00**  **0.00 0.72**  **† Acute**  **R Q #1 =**  **(m g ai /k** **g-bw /day)** **/ LD50**

**Acute R** **Q #2 = mg a**  **i ft-2 /(LD50*bw** **) Avia**  **n Chronic RQ = mg kg-1 s**  **eed / N**  **OAE L**  **Mammalian C hronic RQ =**  **mg a .i./k** **g-bw /day / adjus**  **te d N**  **OAE L**  **Avian (1000 g) Ma**  **mmalian (1000 g) An**  **imal Siz e**  **corn, all or unspecified** 0.0032 97.56 0.03

**Cr op**  **Tol clofos methyl**  **Ri zol**  **ex Floable Fungi cide**  **Density of product (lbs/gal): Dat** **a inputs are in blue**

**Av ian (100 g)**  **Ma mmalian (35 g)**  **Av ian (20 g)**  **Ma mmalian (15 g)**  **Ri sk Quotients**  **† Endpoint** **s Ad**  **ju sted LD50**  **Si ze**  **cl ass for**  **adj usted LD50**  **Re ported** 

**Ad ju**  **sted NOAEL for Mammals 14**  **6**

3 . LD50 PER S QUARE F OOT O UTPUT **Chemi cal**  **: Name of**  **seed treatment formul**  **ation:**

**Percent AI in**  **fo rmul**  **ation: 100%**  1 **9. 99**  **Tested Body Wei**  **ght (g) Av**  **ian LD50: 2000.00**  **12 2159.**  **27 Smal**  **l (20g) Av**  **ia n**  **repro. NOAEC: 500.00**  **2748. 86**  **Medium (100g) 3882.**  **87 Large (1000g)**  **Mammalian LD50: 3500.00**  **20 3760.**  **99 Smal**  **l (15g) Mammalian NOAEL:**  **100.00 3043.**  **05 Medium (35g)**  **1316. 21**  **Large (1000g) Smal**  **l (15g) 13.11**  **Medium (35g) 10.61**  **Large (1000g) 4.59** 

**Cr op**  **Maximum**

**Ap pl**  **ication Rat** **e Ma**  **ximum Seed**

**Ap plication R**  **ate Av**  **ian Nagy Dose Mammalian Nagy**  **Dose Av**  **ailable AI (lbs ai/A)**  **(mg ai/kg seed)**  **(mg ai/kg-bw/day) (mg**  **ai/kg-bw/day) (mg**  **ai ft-2) Sm**  **all** 154.07 128.98 **Me di**  **um** 87.86 89.14 **Large** 39.34 20.67

**Acute (# 1)**  **Acute (# 2) Chroni**  **c Ac**  **ut e (# 1)**  **Ac ute (# 2)**  **Chroni c**  **corn, all or unspeci**  **fied 0.07**  **0. 00**  **1.22 0.03**  **0.00 9.84**  **Acute (# 1)**  **Acute (# 2) Chroni**  **c Ac**  **ut e (# 1)**  **Ac ute (# 2)**  **Chroni c**  **corn, all or unspeci**  **fied 0.03**  **0. 00**  **1.22 0.03**  **0.00 8.40**  **Acute (# 1)**  **Acute (# 2) Chroni**  **c Ac**  **ut e (# 1)**  **Ac ute (# 2)**  **Chroni c**  **corn, all or unspeci**  **fied 0.01**  **0. 00**  **1.22 0.02**  **0.00 4.50**  **† Acute**  **R Q #1 =**  **(m g ai /k** **g-bw /day)** **/ LD50**

**Acute R** **Q #2 = mg a**  **i ft-2 /(LD50*bw** **) Avia**  **n Chronic RQ = mg kg-1 s**  **eed / N**  **OAE L**  **Mammalian C hronic RQ =**  **mg a .i./k** **g-bw /day / adjus**  **te d N**  **OAE L**  **Tol clofos methyl**  **Ri zol**  **ex Floable Fungi cide**  **Density of product (lbs/gal): Dat** **a inputs are in blue**

**Av ian (100 g)**  **Ma mmalian (35 g)**  **Av ian (20 g)**  **Ma mmalian (15 g)**  **Ri sk Quotients**  **† Endpoint** **s Ad**  **ju sted LD50**  **Si ze**  **cl ass for**  **adj usted LD50**  **Re ported** 

**Ad ju**  **sted NOAEL for Mammals**

**Avian (1000 g) Ma**  **mmalian (1000 g) An**  **imal Siz e**  **corn, all or unspecified** 0.0202 608.77 0.21

**Cr op** **147**



## A **PPENDIX** 

## G **: S**  **UMMARY OF** 

## S **UBMITTED** 

## E **NVIRONMENTAL** 

## F **ATE** 

## S **TUDIES 148** 



### I. **Study Summaries Hydrolysis**  (MRID 471147 - 01) Study Classification This study

was classified as acceptable and fulfills the data requirements of EPA Pesticide Assessment Guidelines, Subdivision N, Section 161 - 1 on Hydrol ys is Material and Methods 14 

### C ring labeled - Tolclofos - methyl, 0,O - dimethyl 0 - (2,6 - dichloro - 4 - methylphenyl) phosphorothioate (99.4% pure, 45.0 mCi/mole) at 0.11 ppm concentration (aqueous solubility is 0.3 - 0.4 ppm) was dissolved in sterile buffered solutions at pH 5.0, 7.0 and 9.0, and examined for hydrol ys is in the dark at 25 oC for 30 day s. Samples were taken for analy sis at day s 0, 1, 7, 14, 21, and 30, acidified to pH 2 and extracted with ethyl acetate. Parent and degradates were identif ied by TLC, GC and L SC. Results (1) 14 

### C - Tolclofos - methyl hydroly zed with a half

- life of 51.0 ± 4.4 day s (pH 5), 60.8± 8.0 day s (pH 7) and 62.4± 12.2 day s (pH 9). (2) The isolates (as % of applied) at 30 day s at pH 5 were 63.61% parent, 23.10% 0 - Meth yl 0 - (2,6 - dichloro - 4 - methyl - phenyl) hydrogen phosphorothioate ( **DM -**  **TM** ), 8.16% 0,0 - dimethyl 0 - (2,6 - dichloro - 4 - methylphenyl) phosphate ( **TMO** ), 0.51% 2,6 - Dichloro - 4 - methylphenol ( **ph -**  **CH 3**  

### ). At pH 7, 63.12% parent, 16.08% ( **DM -**  **TM** ), 11.97% ( **TMO** ) and 0.42% (ph CH 3 

### ). At pH 9, 72.92% parent, 11.24% ( **DM -**  **TM** ), 7.66% ( **TMO** ) and 0.64% (ph - CH 3 

### ). (3) The major degradates were the 0 - demethylated product ( **DM -**  **TM** ) and the oxidation of P=S to P=O, a minor product was formed from the cleavage of the phosphate ester bond to form the phenol ( **ph -**  **CH 3**  

### ). (4) The range of material balance was 98 to 103%. **Hydrolysis** (MRID 48341921) Classification This study

was classified as supplemental (conducted at high temperatures) for previousl y submitted study

at 25 oC. Summary The hydroly sis of [phenyl - U 1 4 

### C] - labeled O - 2,6 - dichloro - p - tol yl O,O - dimethyl phosphorothioate (tolclofos - methyl), applied at 0.2 mg a.i./L, was studied at 50  C, 62  C, and 74  C in sterile aqueous buffered pH 4, 7 and 9 solutions incubated in the dark for 50 - 120 hours. Duplicate samples were collected and anal yz ed using L SC and reverse phase HPL C, with identifications confirmed using TLC. Based on first order linear regressio n anal ys is, tolclofos - methyl dissipated with reviewer calculated half

- lives of 63.0 - 100.5 hours at 50  C, 18.4 - 32.1 hours at 62  C, and 5.1 - 9.9 hours at 74  C. At all temperatures, degradation was most rapid at pH 7 and slowest at pH 5. Two transformation p roducts were identified: **DM -**  **TM** (O - 2,6 - dichloro - p - tol yl O - hydrogen, O methyl phosphorothioate) and **ph -**  **CH 3**  

### (DCMP; 2,6 - dichloro - 4 - methylphenol).**149**



### Results Synopsis

**Half -** **life (hours)**  **Major Transformation products (% of the applied); No Minor Degradates were identified**  **50**  **C** pH 4 100.5 DM - TM (max 49.4% at 120.0 hours) pH 7 63.0 DM - TM (max 65.5% at 120.2 hours) pH 9 78.8 DM - TM (max 46.7% at 120.9 hours) and ph - CH 3 (max 12.5% at 120.9 hours) **62**  **C** pH 4 32.1 DM - TM (max 62.7% at 51.2 hours) pH 7 18.4 DM - TM (max 81.3% at 50.4 hours) pH 9 23.7 DM - TM (max 57.4% at 50.6 hours); ph - CH 3 (max 12.7% at 50.6 hours) **74**  **C** pH 4 9.9 DM - TM (max 58.4% at 14.2 hours) pH 7 5.1 DM - TM (max 64.4% at 8.2 hours) pH 9 7.2 DM - TM (max 49.7% at 11.2 hours); and ph - CH 3 (max 12.9% at 11.2 hours) 

### Aqueous Photolysis (MRID 414229 - 02) Study Classification This study

was classified as acceptable and fulfills the data requirements of EPA Pesticide Assessment Guidelines, Subdivision N/Section 161 - 2 on photoly sis. The decision was taken following the registrants’ submittal of additional documentation to satisfy the following issues: the Xenon arc - lamp irradiation spectrum; possibility of shift in the absorption spectrum of tolclofos - methyl to longer wav elengths in water; providing the absorption spectrum of tolclofos methyl in water; clarify

differences between degradation pattern/half - lives reported for hydrol ys is and that for the dark control in this experiment; and specify in what proportions the co - solvent was used. Material and Methods 14 

### C phenyl ring labeled - Tolclofos - methyl, 0 - dimethyl 0 - (2,6 - dichloro - 4 - methylphen yl )**150**



### phosphorothioate at 0.2 ppm concentration (aqueous solubility is 1.0 ppm) was dissolved in sterile buffered solutions at pH 7.0 and examined after irradiation (continuous 24 hours exposure using Xenon arc lamp) and in the dark at 25 oC for 30 day s. Samples were taken for anal ys is at day s 0, 1, 3, 5, 7, 14, 21, and 30, acidified to pH 2 and extracted with ethyl acetate. Parent and degradates were identified by two dimensional TLC and HPL C. Experimental sy stem included traps for CO 2 

### and volatile organics (never exceeded 0.1% of the applied). Results (1) 14 

### C Tolclofos - methyl degraded to 60.1% of the applied radioactivity at day 30 in samples irradiated continuously

with a Xenon arc lamp. In the dark control, 14 

### C Tolclofos - methyl degraded to 80.1% of the applied radioactivity at day 30. Reported photol yt ic half - lives of tolclofos methyl in the pH 7 buffer were 38.3 day s in the irradiated s amples and 76.6 day s in the dark control samples. Half - life of 153 day s was obtained following correction for dark control and 12 hr/12 hr light/dark cycle. (1) The major degradate was identified as O - methyl O - hydrogen O - (2,6 - dichloro - 4 - methyl phenyl) phosphorothioate, designated as **DM -**  **TM** , formed at 12.6% of the applied radioactivity

at day 30 in the irradiated samples. **DM -**  **TM** formation peaked at 7.3% of the applied radioactivity

at day 30 in the dark control samples. (2) Minor degradates detected were O,O - dimethyl O - (2,6 - dichloro - 4 - methylphenyl) phosphate, designated as **TM** O; 2,6 - dichloro - 4 - methylphenol, designated as **Ph -**  **CH 3**  

### ; O methyl O - hydrogen O - ( 2, 6 - dichloro - 4 - methylphenyl) phosphate, designated as **DM**   ** TMO** ; O - methyl S - methyl O - (2,6 - dichloro - 4 - methylphen yl ) phosp horothioate, designated as **TM -**  **SCH 3**  

### ; and others, presumable unknown compounds. The aforementioned degradates were detected in both the irradiated and dark control samples with the exception of **DMO -**  **TMO** and **TM -**  **SCH3** which were found only in the irradiated samp les. No minor degradates formed at greater than 10% with the exception of the unknowns which formed at 11.1% of the applied radioactivity at 30 day s in the irradiated samples. Accumulation of volatiles was insignificant. (3) Material balances for this study ranged from 93.4% of the applied radioactivity at day 21 to 106.6% of the applied radioactivity at day 3 in the irradiated samples. In the dark control samples, material balances ranged from 93.2% of the applied radioactivity at day 21 to 105.5% of the appli ed radioactivity at day 1. **Photolysis on Soil** (MRID 414229 - 02) Study Classification This study

was classified as acceptable and fulfills the data requirements of EPA Pesticide Assessment Guidelines, Subdivision N/Section 161 - 3 on photoly sis on soil. Material and Methods Sieved (2mm) sandy loam soil (70% sand, 18% silt, 12% clay, CEC 7.0 meq/100g, OM 1.32%, pH 7.05) was mixed with distilled water and then added to the bottom surface of a Petri dish. A stock solution (0.74 mg in 240.5 μl acetonitrile, 3.22 x 10 8 

### dpm) of pheny- 14C rizolex (437,340 dpm/μg, radiochemical purity of 99.5%, and 110.9 mg of unlabeled rizolex to 6,160 μl of**151**



### acetonitrile was prepared and applied to the Petri dish containing the soil achieving a starting concentration of 1,126.1 μg/g, or 16 lb/acre. Sunlight intensity , cumulative sunlight energy (250 - 700 nm) and temperature at the soil surface were measured and recorded at 10 or 20 minute intervals throughout the study . The soil chambers were oriented at a perpendicular to the sun 's path. The temperature control chambers were covered with quartz plates for the light exposed samples and normal glass covered with a dark material (unspecified) for the dark controls. Irradiated and non - irradiated samples were anal yz ed in duplicate at time 0, 3, 7, 18, 25, and 30 day s. Samples were extracted with acetone/water, 5: l (v/v) and the extracts were anal yz ed b y LSC and then b y HP LC, Selected samples were analyzed by 2 - dimensional TL C autoradiograph y and GC - MS to identify unknown. An aliquot of soil at each sampling time was combusted to determine total radiocarbon. Humidified ambient air was drawn through the irradiated and non - irradiated samples; gas traps (ethylene glycol and 10% NaOH) were anal yz ed and replaced with fresh material at each sampling interval. Results Rizolex exposed for 30 day s on a sandy loam soil under natural sunlight at 25  C degraded slowly with a calculated first order half - life of 113 day s. Degradation of pheny- 14C rizolex was slow and represented 83.4% of the applied radiocarbon in light exposed samples and 74.8% in dark controls after 30 days. In contrast, the dark control gave a half - life of 71.9 day s which was attributed to a difference in microbial populations and water content of the soils. The major degradate in the irradiated soils was **SM -**  **TM** that reached a maximum of 6.2% by day 30. A minor degradate in the irradiated soils at day 30 was **DM -**  **SM -**  **TM** at 0.2% of applied. The major degradate in the dark control was **DM -**  **SM -**  **TM** which reached 7.6% b y day 30. The minor degradate in the dark control was SM - TM present at 2.5% of applied. Total unknowns accounted for 3.4% and 2.7% in the irradiated and dark controls respectivel y. HPLC and TL C analy sis showed each unknown was a mixture of products. Non - extractable residues accounted for 3.8% and 1.1% in the irradiated and dark controls respectively . Radiocarbon recoveries averaged 95.7% of the applied. No significant amount of volatiles were trapped and CO 2 

### levels were <1.1% at day

30. **Aerobic Soil Metabolism** (MRID 000156106) Study Classification This study

was classified as supplemental for the data requirements of EPA Pesticide Assessment Guidelines, Subdivision N/Section 162 - 1 (Aerobic soil metabolism). The supplemental classification was given to this study mainl y because f

oreign soils were used that may not be typical of US soils where the pesticide is to be used. Material and Methods Samples of Sapporo loam (48% sand, 28% silt, 24% clay , 11.6% organic matter, pH 5.3, CM: 39 meq/100 g) and Azuchi sandy clay loam (62.5% san d, 17% silt, 20.5% clay , 0.4% organic matter, pH 5.5, CM: 13.2 meq/100 g) . Soils were sieved (2 mm), moistened to 75% of field capacity , and maintained in the dark at 25 ± 2 oC for 10 day s. Following this period, the soils**152**



### were treated with ring - labeled [ 14 

### C] tolclofos - methyl (radiochemical purity >99%, specific activity 35.5 mi/m mole, Sumitomo Chemical Co.) in methanol at 20 ppm. The treated soils were incubated in the dark at 25 oC in glass jars attached to a gas collection s ys tem having traps for volat iles (a poly

urethane foam plug) and evolved 14 

### C CO 2 

### (0.5 N sodium hydroxide solution). CO 2 

### - free air (air flow rate 25 - 30 mL/minute) was continuously passed over the soil. Soil moisture content was adjusted as needed to maintain 75% of field capacity. Additional samples of Sapporo loam and Azuchi sandy clay loam soils were autoclaved (1 hour at 121°C and 2 atmospheres on two consecutive day s), moistened to 75% of field capacity, treated with ring - labeled [ 14 

### C] tolclofos - methyl at 20 ppm, and incubated a s described above. Samples of non - sterile soil were taken at 1, 3, 7, 14, 30, 60, 90, 120, and 180 day s post treatment. Sterile soil samples were taken at 1, 3, 7, 14, and 30 day s post - treatment. Gas traps were sampled at the same intervals as the soils. The poly urethane foam plugs were extracted four times with methanol. Radioactivity in the methanol extracts and sodium hydroxide solutions was quantified by

L SC. l h 2 in the sodium hydroxide solutions was quantified by barium chloride precipitation. Soil samples were extracted with 1 N hydrochloric acid: ethyl acetate (3:2). The aqueous layer of the extract was re - combined with the extracted soil and the mixture was re extracted twice with ethyl acetate. Eth ylacetate extracts were combined, evaporated to dry ness, and the residue was analyzed b y TLC on silica gel plates using the following solvent s ys tems: to1uene: acetic acid (7:1), benzene: ethylacetate (1:1), to1uene: ethyl formate: formic acid (5:7:1), hexane: toluene: acetic acid (3:15:2), and chlorof orm. Reference compounds were co chromatographed with the samples and, following development were detected under UV light and by spraying with a 2% palladium chloride in 2 N hydrochloric acid solutions. Radioac tive areas were detected b y autoradiograph y an d quantified by scraping the silica gel from the plates and counting it using L SC. Radioactivity remaining at the origin of the TLC plate was eluted with methanol and reanalyzed by TLC on silica gel plates developed in ethyl acetate: ethano1: water (4:2:1) . Following development, radioactive areas and unlabeled compounds were detected and quantified as described above. Un - extractable [ 14 

### C] residues remaining in the extracted soil were separated into fulvic acid, humic acid, and humin fractions and anal yz ed by combustion and L SC to determine the distribution of radioactivity in the soil organic matter. Results Ring - labeled [ 14 

### C] tolclofos - methyl (radiochemical purity >99%) at 20 ppm, degraded with a half - life of 14 - 30 day s in Sapporo loam and Azuchi sandy c lay loam soils; the registrant calculated half

- lives were 26.3 and 31.8 day s, respectivel y. At 180 days post - treatment, tolclofos - methyl comprised 5.6 - 7.5% of the applied radioactivity ; evolved 14 

### CO 2 

### totaled 17 - 22.9% of the applied; and degradates included ( E ach comprised ≤4.1% of the applied):  O,O - dimethyl O - ( 2,6 - dichloro - 4 - hydrox ym eth ylpenyl) pho sphorothioate ( **TM -**  **CH 2**  

### OH ),  O,O - dimethyl O - ( 2,6 - dichloro - 4 - carbox yphen yl ) phosphorothioate ( **TM -**  **COOH** )  O ,O - dimethyl O - ( 2,6 - dichloro - 4 - methylphen yl) phosphate ( **TMO** ),  O,O - dimethyl O - (2,6 - dichloro - 4 - hydrox ym eth ylphenyl) phosphate ( **TMO -**  **CH 2**  

### OH ),**153**



###  O,O - dimethyl O - ( 2 ,6 - dichloro - 4 - carbox yphen yl ) phos phate ( **TMO -**  **COOH** ),  O - methyl O - (2,6 - dichloro - 4 - methylphenyl)h ydrogen phosphorothioate ( **DM -**  **TM)** ,  O - methyl O - (2,6 - dichloro - 4 - meth ylphenyl)h ydroge n phosphate ( **DM -**  **TMO)** ,  2,6 - dichloro - 4 - methylphenol ( **Ph -**  **CH 3**  

### ),  2,6 - dichloro - 4 - hydroxy methylphen yl( **Ph -**  **CH 2**  

### OH ), and  2,6 - dichloro - 4 - carbox yp henol ( **Ph -**  **COOH** ). Un - extractable [ 14 

### C] residues in the soils comprised 47 - 50.8% of the applied at 180 day s post treatment. Under sterile conditions, [ 14 

### C] tolclofos - methyl at 20 ppm degraded with a half - life of >30 day s in Sapporo loam and Azuchi sandy clay loam soils; the registrant - calculated half - lives were 79.7 and 116.3 day s, respectively . At 30 day s post - treatment, tolclofos - methyl comprised 65.4 - 76.3% of the applied radioactivity , volatiles comprised ≤2% of the applied, and un - extractable [ 14 

### C] residues in the soil comprised 11 - 19.1% of the applied. All degradates detected under non - sterile condition s were detected in the sterile soil at 53.1% of the applied except **Ph -**  **CH 2**  

### OH , which was not detected (<0.01% of the applied) in either soil.

**Aerobic Soil Metabolism** (MRID 427032 - 01) Study Classification This study

was classified as acceptable and fulfil ls the data requirements of EPA Pesticide Assessment Guidelines, Subdivision N/Section 162 - 1 on aerobic soil metabolism. Material and Methods Sieved (2mm) sandy loam soil (70% sand, 18% silt, 12% clay, CEC 7.0 meq/100g, OM 0.8%, pH 7.1) was moistened with distilled water to 75% of 0.33 bar moisture content and incubated in the dark at 25 oC for 19 day s. A stock solution of [phenyl 14 

### C] Rizolex w as adjusted to 30 - mCi/mmol by

dissolving 49.6 mg of non - radiolabeled rizolex in 20 ml of 1/1 benzene/n - hexane containing 50.8 mg of 14 

### C] Rizolex, radiochemical purity of 99.66%. The test solution was purified b y TLC and dissolved in 10 ml of acetonitrile to prepare the dosing solution, and applied to the Petri dish containing the soil achieving a starting concentration of 16.1 μg/g soil, or 32 lb/acre. Inlet air was passed through NaOH trap to remove carbon dioxide and through a water trap to saturate the air with water. Outlet air was passed through to ethyl ene gl ycol traps and NaOH trap. Test vessels were maintained in darkness at 25±1 oC. The soil moisture content was maintained by

adding distilled water at least once every two weeks. Duplicate samples were anal yz ed at time 0, 1, 3, 7, 14, 30, 60, 90, 121, 180, 271 and 365 day s. Samples were extracted with aceto ne/water, 5: 1(v/v) (Extract - 1). The acetone was evaporated from Extract - 1 and the remaining aqueous solution extracted with dichloromethane to form Organic - 1andAqueous - 1. Residues remaining in the soil (Bound - 1) were air - dried and homogenized by grinding, then stored for exhaustive extraction or combustion analy sis. Exhaustive extraction was performed with 5: l (v/v) acetone/0.5 N HC1 and the extract identified as Extract - 2. Remaining soil residues (Bound - 2) were air - dried and homogenized by grinding, then stored for alkaline extraction or**154**



### combustion. Extract - 2 was partitioned into organic and aqueous fractions (Organic - 2 and Aqueous - 2). Humic substances were precipitated from Aqueous - 2, while Bound - 2 was fractionated into fulvic acid, humic acid, and humin . The NaOH trap was analyzed for 14 

### CO 2 

### by precipitation with BaC1 2 

### . Samples from the eth yl ene gl yc ol trap solutions were mixed with methanol for L SC anal ys is, while the remainder was partitioned into Vol - aqueous and Vol organic solutions. Samples of all of the extracts were anal yz ed b y LS C. Identification was accomplished b y performing both HPL C and two - dimensional TL C with authentic standard samples. The performing lab sy nthesized 19 standards, confirmed by NMR and MS, and purchased 2 others for comparison to extracted degradates. Rizolex and its degradation products present in Organic - 1 (Day 60A), Organic - 2 (Day

90 B and Day 180 A), Aqueous - 1 (Day 60 B) and Vol - organic (Day 30 A) were separated by HPL C. Each HPL C fraction was concentrated by nitrogen gas flow, and the aliquot mixed with the authentic standard in methanol prior to HPL C and TLC analy sis. Radioactivity in the various fractions and in silica gel following TLC was measured b y LS C. HPL C was performed to quantify Rizolex and degradates, and to s eparate degradates for confirmative identification from Organic - 1 and 2, Aqueous - 1, Vol - organic and fulvic acid organic extracts. The limit of detection by radio - HPL C was 4.5 x 10 - 3 

### μg of Rizolex. Results Rizolex applied to Tulare sandy loam soil ( 70% sand, 18% silt, 12% clay , 0.8% organic matter, CEC 7.0 meq/100g, pH 7.1) at 25oC degraded slowly with a calculated first order half - life of 79 day s recalculated (59.7 day s reported b y registrant). 14 

### C rizolex represented 5.25% of the applied radiocarbon at 365 day s. While a total of 28 compounds were extracted from the soil, only eight (including parent Rizolex) could be full y identified by comparison with the 21 sy nthesized standards. However, onl y two of the twenty seven degradates exceeded 1% of the appli ed radioactivity

when averaged over the duplicate samples. The two degradates are:  O - Meth ylO - (2, 6 - dichloro - 4 - methyl - phen yl ) h ydrogen phosphorothioate ( **DM -**  **TM** ), which reached a maximum of 18.47% by day 90. **DM -**  **TM** declined from this maximum with a reviewer c alculated half

- life of approximately

56.7 day s ; and  2, 6 - Dichloro - 4 - methylphenol ( **ph -**  **CH 3**  

### ), which reached 2.84% at 121 days. Id entified minor degradates included 3, 5 - dichloro - 4 - hydrobenzoic acid ( **ph -**  **COOH** ); O - methyl - O - hydrogen O - 2, 6 - dichloro - 4 - carbox yph enyl phosphorothioate ( **DM -**  **TMCOOH** ); O - methyl - 0 - hydrogen O - 2, 6 - dichloro - 4 - methylphenyl phosphate ( **DM -**  **TMO** ); O, O - dimethyl O - 2, 6 - dichloro - 4 - carboxy phenyl phosphate ( **TM -**  **COOH** ); and 0, S - dimethyl O - 2, 6 - dichloro 4 - methyl phen yl phosphorothioate ( **SM -**  **TM** ). Non - e xtractable residues in the soil organic fraction accounted for 20.61% of the applied b y day 365. Carbon dioxide increased to 33.29% of the applied b y day 365, while organic volatiles totaled 25.81%. Organic volatiles included: **Rizolex** (18.00%), **Me -**  **ph -**  **CH 3**  

### ( 2,6 - dichloro - 4 - methylanisole; 5.58%) and **ph -**  **CH 3**  

### (1.72%) at day 365. Material balances ranged from 95.76 - 102.70%. **Aerobic Soil Metabolism** (MRID 483419 - 23 supplemented by 483419 - 25) Study Classification**155**



### Note: The study

author stated that the Abington soil e xperiment was designed to identify the rate and route of degradation of tolclofos - methyl, and the Terling and Shuttleworth soil experiments were designed onl y to establish the rate of degradation of tolclofos - methyl. This study

was classified as supplemental for the following reasons:  Temperature during incubation was reported to be 10 ± 2  C.  It was not shown that the soil extraction procedure was the best available method. At study termination, un - extractable soil residues totaled 42.84 - 60.46% o f the applied.  Most samples were anal yzed only using TLC, which did not adequatel y separate many of the transformation products.  Although 20.43 - 44.49% of the applied was recovered from the ethanolamine trap totaled at study termination, it was not confir med that these residues were CO 2 

### . Summary The biotransformation of [ 14 

### C] - O - 2,6 - dichloro - p - tolyl O,O dimethyl phosphorothioate (tolclofos - methyl; radiochemical purity 99.4%), at a nominal concentration of 2 mg a.i./kg, was studied in three soils from the UK:  

### A sandy loam (Abington; pH 7.7, organic matter 2.6%);  

### A loamy

sand (Shuttleworth, pH 6.0, organic matter 2.4%); and  

### A silt loam (Terling; pH 5.2, organic matter 4.6%). The experiments were conducted under aerobic conditions for 112 day s in the dark at 10 ± 2  C and a soil moisture content of 40% of maximum water holding capacity. The test system for the Abington soil consisted of Erlenmeyer flasks containing moist treated soil (100 g dry wt) that were connected to individual volatile traps. The test sy stems for the Shuttleworth and Terling soils consisted of open crystallizing dishes containing moist treated soil (50 g dry wt.) that were placed in incubation chambers; the chambers were attached to the volatile traps. Humidified CO 2 

### - free air was continually drawn through the samples or chambers, then through tubes of ethanediol and ethanolamine. Duplicate samples of each soil were collected 0, 3, 7, 14, 28, 55, 84, and 112 day s post - treatment. The soils were Soxhlet - extracted with acetone: glacial ace tic acid (98:2, v:v), then with acetone. The Abington sandy loam soil was further extracted three times with acetone: 0.5 M HCl (5:1, v:v). The extracts were analyzed by L SC and one dimensional TL C. Abington soil extracts from 7, 28, and 112 day s were also analyzed by HPL C. Portions of the extracted soils were anal yz ed using LSC following combustion. The trapping solutions were anal yz ed by L SC; identification of CO 2 

### was not confirmed. The incubation temperature and soil moisture content were reportedl y maintained throughout the experiment; supporting data were not provided. No determinations were made to verify that aerobic conditions were maintained in the soils. The soils were viable at initiation and termination. Overall [ 14 

### C] residue recoveries av eraged 96.22  3.11% (range 88.44 - 100.22%) of the applied for the Abington sandy l oam soil, 95.06  3.92% (range 84.08 - 99.18%) for the Shuttleworth loamy sand soil and 93.74 ± 4.18% (range 87.40 - 100.65%) for the Terling silt loam soil. Based on nonlinear regression analy ses, tolclofos - methyl dissipated with reviewer - calculated half - lives of 19.2 day s in Abington sandy loam soil, 22.6 day s in Shuttleworth loamy sand soil**156**



### and 30.9 day s in the Terling silt loam soil. Transformation products were identified only in the Abington soil; six minor transformation products were identified:  

### 3,5 - dichloro - 4 - hydroxy benzoic acid ( **ph -**  **COOH** );  

### 2,6 - dichloro - 4 - (h ydrox ymethyl)phenol ( **ph -**  **CH 2**  

### - **OH** );  

### O - 2,6 - dichloro - p - tolyl O - hydrogen, O - methyl phosphorothioate ( **DM -**  **TM** );  

### 3,5 - dic hloro - 4 - dimethoxy phosphoryloxy- benzoic acid ( **TM -**  **COOH** );  

### (2,6 - dichloro - 4 - methyl - phenyl) dimethyl phosphate ( **TMO** ); and  

### (2,6 - dichloro - 4 - methyl - phenyl) methyl hydrogen phosphate ( **DM -**  **TMO** ). Total transformation products were a maximum of 6.69% of the applied in the Shuttleworth loamy sand soil and 37.15% in the Terling silt loam soil; no single compound was present at >5% of the applied. In the three soils at study termination, non - extractable [ 14 

### C] residues totaled 42.84 - 60.46% of the applied and CO 2 

### totaled 20.43 - 45.65%. In Shuttleworth loam y sand soil incubated at 15°C, tolclofos - methyl dissipated with a nonlinear reviewer - calculated half

- life of 26.5 day s. Transformation products were not individually identified but totaled a maximum of 14.56% of the app lied at 14 day s post - treatment. Results **Abington sandy loam soil at 10°C.** Linear half

- life: 28.2 day s (r2 

### = 0.9732). Nonlinear half

- life: 19.2 day s (r2 

### = 0.9911). Observed DT50: ca . 14 day s. Major transformation products: CO 2 

### (maximum 45.65% at 112 day s). Minor transformation products:  

### 3,5 - Dichloro - 4 - hydroxy benzoic acid ( **ph -**  **COOH** , maximum 0.77% at 28 day s).  

### 2,6 - Dichloro - 4 - (h ydrox ymethyl)phenol ( **ph -**  **CH 2**  

### OH , maximum 0.29% at 28 day s).  

### O - 2,6 - Dichloro - p - tol ylO - hydrogen, O - methyl phosphorothioate ( **DM -**  **TM** , maximum 0.50% at 28 day s).  

### 3,5 - Dichloro - 4 - dimethoxy phosphoryloxy- benzoic acid ( **TM -**  **COOH** , maximum 1.67% at 7 day s).  

### (2,6 - Dichloro - 4 - methyl - phenyl) dimethyl phosphate ( **TMO** , maximum 0.37% at 28 day s).  

### (2,6 - Dichloro - 4 - methyl - phenyl) methyl hydrogen phosphate ( **DM -**  **TMO** ; maximum 0.19% at 7 days). **Shuttleworth loamy sand soil at 10°C.** Linear half

- life: 23.2 day s (r2 

### = 0.9920). Nonlinear half

- life: 22.6 day s (r2 

### = 0.9986). Observed DT50: 14 - 28 day s. Major transformation products: **CO 2**  

### (maximum 27.27% at 112 day s). Minor transformation products: None identified. **Terling silt loam soil at 10°C.** Linear half

- life: 30.7 day s (r2 

### = 0.9737). Nonlinear half

- life: 30.9 day s (r2 

### = 0.9847). Observed DT50: ca. 30 day s.**157**



### Major transformation products: **CO 2**  

### (maximum 20.43% at 112 day s). Minor transformation products : None identified. **Aerobic Soil Metabolism** (MRID 483419 - 24) Study Classification This study

was classified as acceptable and fulfills the data requirements of EPA Pesticide Assessment Guidelines, Subdivision N/Section 162 - 1 on aerobic soil metabolism. However, the following deficiencies were identified:

 

### It was not shown that the soil extraction procedure was the best available method. At study termination, un - extractable soil residues totaled 45.4 - 56.1% of the applie d. This deficiency initiated the consideration of calculating the total toxic residues half - lives to account for the un - extracted un - identified residues.

 

### Single rather than replicate samples were anal yz ed at each sampling interval .  

### The pesticide use histo ry at the test sites was not reported, and it was not confirmed that the soils were free of pesticide residues.

 

### The test soils were from the UK, and were not compared with soils ty pical of tolclofos methyl use areas in the US. Summary The biotransformatio n of [phenyl - U 14 

### C] - labeled O - 2,6 - dichloro - p - tolyl O,O dimethyl phosphorothioate (tolclofos - methyl), at 2 mg a.i./kg, was studied in four English soils:

 

### A sandy loam (PT - 102; pH 6.9 - 7.1, organic matter 4.3%);  

### A sandy loam (PT - 103, pH 4.9 - 5.5, organic matt er 2.4%);  

### A clay

loam (SK 15556090; pH 6.2 - 6.7, organic matter 7.8%); and  

### A clay

loam (SK 960087; pH 7.2 - 8.0, organic matter 4.7%). The experiments were conducted under aerobic conditions for 90 day s in the dark at 20 ± 1  C and a soil moisture content of 45% of maximum water holding capacity. The test system consisted of Erlenmeyer flasks containing moist treated soil (50 g dry wt) that were connected to individual volatile trapping s ys tems. Humidified air was pulled through the sample flask, then through pol yurethane foam and tubes of ethanediol, 2% paraffin in x yl ene, and 2M NaOH. Single vessels of each soil were collected at 0, 1, 3, 7, 15, 30, 62, and 90 days post - treatment. Samples were Soxhlet - extracted for 18 hours using acetone: glacial aceti c acid (98:2, v:v (98:2, v:v), and aliquots of the extracts were analyzed by L SC and HPL C. Identifications were confirmed using one - dimensional TL C. Portions of the extracted soils were anal yz ed using LS C following combustion, and samples containing maxi mum concentrations of un - extracted residues were fractionated into fulvic acids, humic acids, and humin. The poly urethane foam extracts and liquid trapping solutions were anal yz ed b y LS C; CO 2 

### was confirmed by precipitation with barium chloride. The inc ubation temperature and soil moisture content were reportedl y maintained throughout the**158**



### experiment; supporting data were not provided. No determinations were made to verify that aerobic conditions were maintained in the soils. The soils were viable at in itiation and termination. Overall [ 14 

### C]residue recoveries averaged 95.9  2.3% (range 91.8 - 98.7%) of the applied for the PT - 102 sandy

loam soil, 94.7  3.0% (range 91.5 - 99.3%) for the PT - 103 sandy loam soil, 96.2  2.7% (range 92.1 - 100.8%) for the SK 1555 6090 clay loam soil, and 94.2 ± 3.0% (range 91.2 - 99.3%) for the SK 960087 clay loam soil. There was some loss of radioactivity from the test sy stems over time Based on nonlinear regression analy ses, tolclofos - methyl dissipated with reviewer - calculated hal f - lives of 3.5 day s in PT - 102 sandy loam soil, 2.0 day s in the PT - 103 sandy loam soil. 5.6 day s in SK 15556090 clay loam soil and 5.9 day s in the SK 960087 clay loam soil. Two nonvolatile transformation products were identified:  

### DM **- TM**  (O - 2,6 - dichloro - p - t olyl O - hydrogen, O - methyl phosphorothioate and  

### ph **- CH**  **3** 

### ( 2 - 6 - dichloro - 4 - methylphenol). In the four soils at study

termination, non - extractable [ 14 

### C] residues totaled 45.4 - 56.1% of the applied and **CO 2**  

### totaled 36.9 - 42.6%. Results **Test system used: PT**  **- 102**  **sandy loam soil.** Linear half

- life: 16.7 day s (r2 

### = 0.8044); TTR=139 day s Nonlinear half

- life: 3.5 day s (r2 

### = 0.9943) Observed DT50: ca . 3 day s Major transformation products: CO 2 

### (maximum 36.9% at 90 day s) Minor transformation products: O - 2,6 - Dichloro - p - tol ylO - hydrogen, O - methyl phosphorothioate ( **DM -**  **TM** , maximum 1.1% at 1 day) 2,6 - Dichloro - 4 - methylphenol ( **ph -**  **CH 3**  

### , maximum 1.3% at 3 day s) **Test system used: PT**  **- 103 sandy loam soil.**  Linear half

- life: 17.0 day s (r2 

### = 0.6844); TTR=128 day s Nonlinear half

- life: 2.0 day s (r2 

### = 0.9943) Observed DT50: 1 - 3 day s Major transformation products: **DM -**  **TM** (maximum 13.3% at 3 day s) **CO 2**  

### (maximum 40.9% at 90 day s) Minor transformation products: **ph -**  **CH 3**  

### (maximum 8.0% at 3 day s) **Test system used: SK 15556090 clay loa**  **m soil.**  Linear half

- life: 16.3 day s (r2 

### = 0.8295); TTR=114 day s Nonlinear half

- life: 5.6 day s (r2 

### = 0.9989)**159**



### Observed DT50: 3 - 7 day s Major transformation products: **CO 2**  

### (maximum 39.6% at 90 day s) Minor transformation products: **DM -**  **TM** (maximum 3.6% at 7 day s ) **ph -**  **CH 3**  

### (maximum 2.9% at 7 day s) **Test system used: SK 960087 clay loam soil.**  Linear half

- life: 16.9 day s (r2 

### = 0.8123); TTR= 98 day s Nonlinear half

- life: 5.9 day s (r2 

### = 0.9974) Observed DT50: ca . 7 day s Major transformation products: **CO 2**  

### (maximum 42.6% at 90 day s) Minor transformation products: **DM -**  **TM** (maximum 0.6% at 15 day s) **ph -**  **CH 3**  

### (maximum 4.1% at 7 day s) **Aerobic and Anaerobic Soil Metabolism** (MRID 428183 - 01) Study Classification This study

was classified as acceptable and fulfills th e data requirements of EPA Pesticide Assessment Guidelines, Subdivision N/Section 162 - 1 on aerobic soil metabolism. Material and Methods Air - dried sieved (2 mm) sandy loam soil (70% sand. 18% silt, 12% clay , 0.8% organic matter, pH 7.1, and CEC 7 :0 meq/1 00 g) was weighed (20 g dry weight) into beakers, moistened t o 75% of 0.33 bar and incubated in the dark at 25 ± 1  C for 18 day s. After the pre - incubation, the soi1s were treated a t 16.6 ppm with phenyl ring labeled [U - 14C] tolclofos (0 - 2,6 - dichloro - p - t olyl 0 ,0 - dimethyl phosphorothioate: radiochemical purity 99.5%, specific activity

59.5 mCi /m Mol , Sumitomo Chemical Company) , dissolved in acetonitri1e. The individual treated soil samples were mixed "thoroughl y" and transferred to glass incubation ve ssels equipped with inlet and outlet ports. The vessels were attached to a continuous airflow sy stem. Humidified, CO 2 

### - free air was drawn (20 - 30 mL/minute) through the sample vessel, then through ethylene gl yc ol (two traps) and 0.5 N NaOH trapping solutions . The samples were incubated in a temperature controlled room at 25 ± 1  C in darkness. The soi1 was remoistened to 75% of 0.33 bar "at least" once every

2 weeks. Duplicate vessels of treated soil were collected for analy sis a t 0, 10, 21, and 32 day s post - treatment. At 32 day s post - treatment, al1 remaining treated soi1 samples were \ flooded with 20 mLof O 2 

### - free water that had been amended with 0.1g of glucose. The samples were stirred to remove trapped air, the redox potentia1 was measured, and the incub ation vessels were flushed with nitrogen gas. The inlet and outlet ports were sealed; and the vessels were returned to the temperature controlled room. After 10, 11, 31. 42, and 60 day s of anaerobic incubation (42, 63. 74, and 92 day s post - treatment) the v essels were purged with nitrogen gas for 5 minutes: effluent gases were passed through ethylene gl ycol and 0.5 N I NaOH trapping solutions. "On each**160**



### sampling day

of volatile trap solutions, the incubation vessel s and connections were rinsed with acetone". After collection of the headspace gases, duplicate vessels of flooded, treated soil were collected for anal ys is. The pH and redox potential of the samples were measured at the time of sampling. The flooded soil samples were anal yz ed according t o the sch eme presented in Figure 4 of the report. After sampling, the flooded soils were centrifuged, and the water and soil phases were separated. Aliquots of the floodwater were analyzed for total radioactivity using L SC. The remaining water was partitioned three times against methylene chloride; aliquots of the combined methylene chloride extracts and of the extracted floodwater were anal yz ed using LS C. Additional aliquots of the methylene chloride solutions were washed with a saturated NaCl solution, and filtere d through a silicone - treated phase separator. The filtered solutions were concentrated at 40  C under reduced pressure; the concentrated solutions were diluted with methanol , filtered ( 0.5 um) , and anal yz ed b y reverse - phase HPLC using a Sumipax ODS - A212 column coupled with a u - Bondapac C - 18 guard column , and eluted with water : acetonitrile: methanol (gradient from 70: 0: 30 t o 20: 30: 50 t o 70: 0: 30) ; the column was equipped with UV (254 nm) and radioactive flow detection. Aliquots o f the extracte d floodwater were freeze dried, the residues were dissolved in methanol or methanol: water (1:l or 4:1, v:v), and aliquots of the solutions were filtered (0.5 um) and anal yz ed by HPLC as described. All samples were co chromatographed with non - labeled reference standards (Figure 3 of the report). L imits of detection were reported t o be 0.00045 μg for L SC and 0.0045 μg for HPLC. The treated - soi1 samples from the aerobic and anaerobic phases of the study were extracted three times with acetone: water (5: 1. v: v) b y shaking for 10 minutes per extraction; after each extraction, the mixtures were centrifuged and the supernatant removed. The extracts were combined, and aliquots of the extracts were analyzed f o r total radioactivity using L SC; the extracted soi 1 was a air - dried, and subsamples were anal yz ed b y LS C following combustion. The acetone was removed from the extracts using a rotary evaporator at 40  C. The resulting aqueous solutions were partitioned three times against methylene chloride; the methylen e chloride extracts from each solution were combined, and aliquots of the methylene chloride and aqueous phases were analy zed using LSC. Prior t o HPL C anal ys is, additional aliquots of the methylene chloride and aqueous phases were prepared as described wi th a saturated NaCl solution and by

freeze drying , respectivel y. The acetone: water - extracted soil samples were further extracted three times with acetone: 0.5 N HC1 (5:1, v: v) by

shaking for 10 minutes per extraction; after each extraction, the mixtures were centrifuged and the supernatant removed. The extracts were c ombined, and a1iquots were anal yz ed using LSC; the extracted soil was air - dried, and subsamples were anal yz ed b y LSC f o l lowing combustion. The acetone was removed from the acetone: HC1 extracts by rotary evaporation at 40  C; the resulting aqueous solutions were partitioned three times against methylene chloride as described and a1iquots of the resulting methylene chloride and aqueous phases were analyzed using LSC. Prior t o HPL C anal ys is, additional aliquots of the methylene chloride extracts were prepared as described with a saturated NaCl solution. The extracted aqueous solution was neutralized with a 0.5 N NaOH solution, and the resulting precipitate was**161**



### separated from the solution by centrifugation; a1iquots of the supernatant were anal yz ed using L SC, and the radioactivity in the precipitate ("humic substance" was determined by difference (rather than direct anal ys is). Additional a1iquots of the neutralized supernatants were prepared by freeze - drying prior t o HPL C anal ys is. Id entification of tolcl ofos methyl and its degradates isolated by HPLC was confirmed 'using two dimensional TL C on plates (ty pe unspecified) developed in chloroform: methanol 9: 1, v: v) in the first direction and either to1uene: ethylformate: formic acid (5:7: 1, v:v:v) or eth ylacetate: ethanol: water (4':2:1, v:v:v) in the second direction. [ 14 

### C] residues on the plates were visualized using auto - radiograph y. All aliquots of the acetone rinses of the incubation vessels and connections were anal yz ed b y LSC. Aliquots o f the e thylene glycol trapping solutions were di1uted with methanol and anal yz ed f o r total radioactivity using L SC. The remaining ethylene gl ycol solutions were diluted with water and partitioned three times against methylene chloride, the methylene chloride ex tracts were combined and aliquots of the methylene chloride extracts and the extracted solutions were anal yz ed using L SC. Additional a1iquots of the methylene chloride extracts were washed with a saturated NaCl solution, and fi1tered through a silicone - tre ated phase separator; the filtered solutions were combined with the associated acetone /rinses of the incubation equipment, filtered (0.5 um), and anal yz ed using HPL C as described. Aliquots of the NaOH trapping solutions were analyze: using LS C. Identification of [ 14 

### C] residues in the NaOH solution as CO 2 

### was confirmed by precipitation with barium chloride. Results Phenyl ring - labeled [U - 14C] tolclofos methyl (0 - 2.6 - dichloro - p - tol yl0.0 - dimethyl phosphorothioate: radiochemical purity 99.5%). at 16.6 1 ppm , degraded with an observed halflife of >60 day s in anaerobic (flooded plus nitrogen atmosphere) sandy loam soi1 that was incubated in the dark at 25  C for 60 day s following 32 day s of incubation under aerobic conditions. Registrant calculated half - live s were 52.7 and 80.0 day s for the aerobic and anaerobic phases of the experiment, respectivel y. [ 14 

### C] tolclofos methyl comprised 100.88 - 101.49% of the applied immediately post - treatment. 64.24 - 68.89% after 32 day s of aerobic incubation, 59.71 - 61.44% after 10 day s o f anaerobic incubation (42 day s post - treatment. 48.44 - 49.19% after 31 day s of anaerobic incubation and 39.47 - 40.12% after 60 day s of anaerobic incubation. Eleven degradates were identified in the flooded soi1:

 0 - methyl 0 - hydrogen 0 - 2 .6 - dichloro - 4 - kethylphenyl phosphorothioate ( **DM -**  **TM** );  2.6 - dichl oro - 4 - methyl phenol ( **ph -**  **CH 3**  

### ) ;  4 - methyl phenol ( **p -**  **cresol** );  3.5 - dichloro - 4 - hydroxy benzoic acid ( **ph -**  **COOH** ) :  3.5 - dichloro - 4 - hydroxy benzyl alcohol ( **ph -**  **CH 2**  

### OH );  0 - methyl 0 - hydrogen 0 - 2,6 - di chdoro - 4 - carbox yp he nyl phosphate ( **DM -**  **TM -**  **COOH** );  0 - methyl 0 - hydrogen '0 - 2, 6 - dichloro - 4 - methyl phenyl phosphate ( **DM -**  **TMO** );  0.0 - dimethyl 0 - 2, 6 - dichl oro - 4 - carbox yphen ylphosphorothioate ( **TM -**  **COOH** );  0.0 - dimethyl 0 - 2.6 - di chloro - 4 - methylphen ylphosphate ( **TMO** );**162**



###  0, S - dimethyl 0 - 2,6 - dichloro - 4 - methyl phen ylphosphorothioate ( **SM -**  **TM** ) ; and  2 - chloro - 4 - methyl phenol ( **DC -**  **ph -**  **CH 3**  

### ). DM - TM, the major degradate, increased steadily to an average 12.63% of the applied after 32 day s of aerobic incubation and 31.19% after 60 day s of anaerobic incubation. The degradate ph CH, averaged a maximum 7.99% of the applied after 42 day s of anaerobic incubation, and p cresol was 55.06% after 60 day s of anaerobic incubation. No other identified degradate was isolated at >1.0% of the applied. At least 18 unide ntified [ 14 

### C] compounds were isolated from the soi1 or water, each at ≤1.28% of the applied. Evolved CO 2 

### and other [ 14 

### C] volat1ies, including: 2, 6 - dichloro - 4 - methylani sole ( **Me -**  **ph -**  **CH** ), totaled 2.86 - 5.31% and 2.32 - 2.59% of the applied, respectivel y, after 32 days of aerobic incubation, and 4.50 - 5.75% and 3.18 - 3.46%, respectively , after 60 days of anaerobic incubation. At all sampling intervals, un - extracted [ 14 

### C] residues averaged <5.0% of the applied, and "humic substance" averaged <2.0%. After 60 day s o f anaerobic incubation, the distribution of [ 14 

### C] residues between the soi1 and water fractions was approximately

2: 1. Material balances were 101.51 - 102.07% of the applied immediately after post - treatment, 95.34 - 96.21% after 32 day s of aerobic incubation , and 93.36 - 96.44% after 60 day s of anaerobic incubation. **Anaerobic Soil Metabolism** (MRID 000156106) Study Classification This study

was classified as supplemental and partially fulfills the data requirements of EPA Pesticide Assessment Guidelines, Subdivision N/Section 162 - 1 on anaerobic soil metabolism. Material and Methods Same as the aerobic soil metabolism above (MRID 000156106) except that the soils (30 g) in 50 - ml beakers were moistened with distilled water to 75 % of 0.33 bar , and incubated at 25±2  C for 2 weeks in BBL GasPak anaerobic s ys tems (Becton Cickinson and Company). Then, the soils were treated with 14 

### C - tolclofos - methyl at a rate of 20 ppm. **Results** The half - life of disappearance for tolclofos - methyl under anaerobic conditions was 34 and 44 day s for Sapporo and Azuchi soils, respectivel y. Under these conditions, DM - TM and ph - CH3 graduall y increased with time, amounting to 4.8 - 7.7 % and 2.6 - 3.7 % of the applied 14C at 60 day s post - treatment. The bound 14 

### C amounted to a pproximately

31 - 39 % of the applied 14 

### C during the same periods, whereas the amount of 14 

### CO 2 

### did not exceeds 1.0%. **Aerobic Aquatic Metabolism** (MRID 483419 - 26) Study Classification This study

is [Acceptable]. De viations from the objectives of OCSPP guidelines were noted. Only sediments, with associated waters, from the United Kingdom were used in this study , and it was not established that the application rate (equivalent to 2 kg/ha) was equivalent to the maximum field use rate. Only single samples were c ollected at each sampling interval.**163**



### Summary The biotransformation of [phenyl - U 14 

### C] - labeled O - 2,6 - dichloro - p - tolyl O,O - dimethyl phosphorothioate (tolclofos - methyl), at 0.67 mg a.i./kg, was studied in two freshwater aquatic sy stems from the United Kingdom:

 

### A pond water/sandy silt loam sediment (water, pH 7.91; sediment, pH 6.9 - 7.2, organic matter 12.7%) s ys tem and  

### A lake water/sandy loam sediment (water, pH 6.55; sediment, pH 5.7 - 6.1, organic matter 5.8%) s ys tem. The experiments were conducted under aerobic conditions for 100 day s in the dark at 20 °C. The test sy stems consisted of borosilicate glass bottles containing water ( ca . 95.4 mL) and sediment ( ca . 14 or 24 g dry

wt.) that we re attached to continuous flow - through volatile trapping s ys tems (poly urethane foam [PUF], ethylene glycol, 2% paraffin in xylene and 2M NaOH). A single sample for each s ys tem was collected at 0, 1, 2, 3, 7, 30, 62, 76 (lake s ys tem only) and 100 day s post - treatment. Following removal of the water, the sediment was Soxhlet - extracted with acetone: glacial acetic acid (98:2, v:v) . Residues were recovered from the water layer using C18 solid - phase extraction. PUF was extracted with acetonitrile. Water laye rs, sediment extracts, extracted sediment, trapping solutions and PUF extracts were analyzed for total radioactivity using L SC. W ater, sediment and PUF extracts were also anal yz ed b y HPLC and one dimensional TL C. Non - extractable residues were characteriz ed b y organic matter fractionation. The test conditions presented in the study protocol appear to have been maintained throughout the experiments. T hroughout the study , redox potentials and dissolved oxygen in the water layers were ca . +275 to +475 mV an d ca . 25 - 95%, respectivel y, with redox potentials in the sediments of ca . - 50 to +150 mV. O verall recovery

of [ 14 

### C] residues averaged 94.4  2.2% (range 90.9 - 97.0%) of the applied for the sandy silt loam (pond) sy stem and 92.2  4.7% (range 81.6 - 97.1%) fo r the sandy loam (lake) sy stem. There were no consistent patterns of loss of radioactivity from the sy stems over time. Tolclofos - methyl dissipated with reviewer - calculated nonlinear half - lives of 18 day s in the sandy silt loam (pond) sy stem and 24 day s in the sandy loam (lake) s ys tem. In both sy stems, volatilized tolclofos - methyl was detected at a maximum 12.7 - 31.6% of the applied. Four transformation products were identified:  

### O - 2,6 - dichloro - p - tolyl O - hydrogen, O - methyl phosphorothioate ( **DM -**  **TM** ) ;  

### 2,6 - dichloro - 4 - methylphenol ( **ph -**  **CH 3**  

### [DCMP ]);  

### (2,6 - dichloro - 4 - methyl - phenyl) methyl hydrogen phosphate ( **DM -**  **TMO** , oxon product); and  

### 3,5 - dichloro - 4 - dimethoxy phosphoryloxy- benzoic acid ( **TM -**  **COOH** ). DM - TM was a major product in both sy stems, while **ph -**  **CH 3**  

### [DCMP ], **DM -**  **TMO** and **TM**   ** COOH** were minor products in both sy stems. Also in both systems, non - extractable residues were a maximum 25.9 - 35.0% of the applied and CO 2 

### totaled 35.6 - 52.5%.**164**



### Results **Test system used: United Kingdom pond water -**  **sandy silt loam sediment syste m**  Linear half

- life in water: 8.2 day s (r2 

### = 0.7212). Linear half

- life in sediment: 19.5 day s (r2 

### = 0.9945). Linear half

- life in the total sy stem: 18.5 day s (r2 

### = 0.9955). Nonlinear half

- life in water: 0.45 day s (r2 

### = 0.8905). Nonlinear half

- life in s ediment: 22.1 day s (r2 

### = 0.9981). Nonlinear half

- life in the total sy stem: 17.7 day s (r2 

### = 0.9979). Major transformation products (total sy stem): **DM -**  **TM** (maximum 23.4% of applied at 30 days post - treatment). **CO 2**  

### (maximum 52.5% at 100 day s). Minor transformation products (total sy stem): **ph -**  **CH 3**  

### [DCMP] (maximum 6.5% of applied at 30 day s). **DM -**  **TMO** (maximum 2.9% at 62 day s). **TM -**  **COOH** (maximum 0.2% at 3 - 7 day s). **Test system used: United Kingdom lake water -**  **sandy loam sediment system.** Linear half

- lif e in water: 9.3 day s (r2 

### = 0.9122). Linear half

- life in sediment: 30.9 day s (r2 

### = 0.9519). Linear half

- life in the total sy stem: 25.4 day s (r2 

### = 0.9708). Nonlinear half

- life in water: 0.95 day s (r2 

### = 0.9157). Nonlinear half

- life in sediment: 38.5 day s (r2 

### = 0.9809). Nonlinear half

- life in the total sy stem: 23.8 day s (r2 

### = 0.9739). Major transformation products (total sy stem): **DM -**  **TM** (maximum 13.4% of applied at 30 days post - treatment). **CO 2**  

### (maximum 35.6% at 100 day s). Minor transformation products (tot al sy stem): **ph -**  **CH 3**  

### [DCMP] (maximum 2.6% of applied at 30 day s). **DM -**  **TMO** (maximum 5.4% at 30 day s). **TM -**  **COOH** (maximum 0.9% at 7 day s). **Anaerobic Aquatic Metabolism** (MRID 431281 - 01) Study Classification This study

was classified as acceptable and fulfills the data requirements of EPA Pesticide Assessment Guidelines, Subdivision N/Section 162 - 3 on anaerobic aquatic metabolism. Material and Methods Air - dried, sieved (2 mm) sandy loam soil (70% sand, 18% silt, 12% clay . 0.8% organic matter.**165**



### pH 7.1, CEC 7.0 me q/100 g) was weighed (10 g dry weight) into glass containers and mixed with 40 mLof a peptone solution (2.5 mg/mL) that had been treated with bubbling nitrogen gas for 60 minutes. The samples were mixed "thoroughl y" , the containers were sealed, and the so i1: water mixtures were incubated in the dark at 25 ±1 °C for 31 day s. After the pre - incubation, the samples were treated a t 16.5 ppm (based on the soi1dry weight) with phenyl ring - labeled [U 14 

### C] tolclofos methyl (0 - 2.6 - dichloro - p - tol yl0.0 - dimethyl phos phorothioate; radiochemical purity 99.6%, specific activity

30.0 mCi/mMol. Sumitomo Chemical Company) dissolved in acetonitrile. The individual treated soi1 samples were mixed "thoroughl y" and transferred to glass incubation vessels equipped with inlet and outlet ports. The vessels were purged with nitrogen immediatel y post - treatment and a t approximately 2 - week intervals; nitrogen gas was drawn through the sample vessel, then through ethylene glycol and 0.5 N NaOH trapping solutions. The inlet and out1et p orts remained closed except during volatile collection. "On each sample day

of the volatile trap solutions, the incubation vessels and connections were rinsed with acetone. The samples were incubated in a temperature - controlled room at 25 ±1 °C in darkness . Duplicate vessels of the treated soi1: water solutions were collected for analy sis at 0, 1, 3, 7, 14, 30, 59, 62, 92, 120, 182, 282, and 364 day s post - treatment. The pH and redox potential of the samples were measured a t the time of sampling. The soil : water solutions were anal yz ed according to the schemes presented in Figures 5 and 6 of the study report. After sampling, the samples were centrifuged, and the water and soi1 phases were separated. A1iquots of the water phase were anal yz ed for total radio activity using LSC. The remaining water was partitioned three times against methylene chloride: aliquots of the combined methylene chloride extracts and of the extracted floodwater were anal yz ed using LS C. Additional aliquots of the methylene chloride solutions were washed with a saturated NaCl solution and fi1tered through a si1icone - treated' phase separator. The filtered solutions were concentrated a t 40 °C under reduced pressure; the concentrated solutions were diluted with methanol, filtered (0.5 μm) , and anal yz ed b y reverse - phase HPLC using a Sumipax 00s - A212 column coupled with a μ - Bondapak C - 18 guard column, and eluted with a water: acetonitrile: methanol gradient : the column was equipped with UV (254 or 210 nm) and radioactive flow detection. Aliq

uots of the extracted flood water were freeze - dried. The residues were dissolved in methanol: water (4:1, v: v), and aliquots of the solutions were filtered (0.5 um) and anal yz ed by HPLC as described. All samples were co - chromatographed with non - labeled re ference standards. Limits of detection were reported to be 0.00045 μg for LSC and 0.0045 μg for HPLC. The soi1 fractions were extracted three times with acetone: water (5: 1, v: v) by shaking for 10 minutes per extraction; after each extraction, the mixtures were centrifuged and the supernatant removed. The extracts were combined: and aliquots of the extracts were analyzed for total radioactivity

using LSC. The acetone was removed from the extracts using a rotary evaporator at 40 °C . The resulting aqueous solutions were partitioned three times against methylene chloride; the methylene chloride extracts from each solution were combined, and aliquots of the methylene chloride and aqueous phases were anal yz ed using LSC. Prior t o HPL C analy sis, additional aliquots of the methy 1ene chloride and aqueous phases were prepared as described with a saturated NaCl solution. The extracted aqueous solution was neutralized with a 0.5 N NaOH solution, and the resulting precipitate was separated from the solution by centrifugation; aliquots of the supernatant were analyzed using L SC, and the radioactivity in the precipitate ("humic**166**



### substance”) was determined by difference (rather than direct analy sis). Additional aliquots of the neutralized supernatants were prepared b y freeze - drying prior t o HPL C analy sis. Id entification of tolclofos methyl and DM - TM isolated b y HP LC was also confirmed using LC/MS. In addition, identification of t olclofos methyl and DM - TM was confirmed using two dimensional TL C on silica gel plates developed in chloroform: methanol (9: 1, v: v) in the first direction and either toluene: ethyl formate: formic acid (5:7: 1, v: v: v) or ethyl acetate: ethanol: water ( 4: 2: 1, v: v: v) in the second direction. Identification of DM - TM was also confirmed using one directional TLC on silica gel plates developed ethyl - acetate: ethanol :water (4: 2: 1, v:v: v) and 2 - propanol : "ammonia water" :water (9: 1:2, v:v:v) . I dent ifications of ph - CH 3 

### , DC ph - CH 3 

### and p - cresol isolated by HPL C, were confirmed using one - dimensional TL C on si1ica gel p1ates developed chloroform: acetone (9: 1, v: v) , and/ two - dimensional TL C on silica gel plates developed in n - hexane : - acetone (5: 2, v: v) in the first direction and chloroform: acetone (9:1, v:v) in the second direction. All compounds were co - chromatographed with reference standards. [14c] residues on the plates were visualized using autoradiography. The extracted' soils that contai ned >9.0% of the applied radioactivity were further extracted with 0.5 N NaOH b y shaking for 24 hours, then centrifuged. The NaOH extract was acidified; the resulting precipitate (humic acid) and supernatant (fulvic acid) were separated b y centrifugation, the precipitate was dissolved in a 0.5 N NaOH solution, and aliquots of the NaOH solution and supernatant were anal yz ed by L SC. The extracted sediment (humin fraction) was air - dried and anal yz ed using LSC following combustion. Aliquots of the acetone rins es of the incubation vessels and connections were anal yz ed b y LS C. Aliquots of the ethylene gl ycol trapping solutions were mixed with methanol and anal yz ed for total radioactivity using LSC. Aliquots of the NaOH trapping solutions were anal yz ed using LSC. Identification of [ 14 

### C] residues in the NaOH solution as CO 2 

### was confirmed b y precipitation with Bariurn chloride. To confirm the production of 14 

### CH4 

### from 14 

### C - ph - CH 3 

### during degradation, an anci1lary experiment was conducted in which sieved sandy l oam s oil was weighed (20 g dry weight) into a glass container and mixed with 80 mLof peptone solution. The container was sealed with an open top screw cap that was equipped with a Teflon - 1aminated si1icone disc, and the sample was incubated in the dark at 25 ± 1 oC for 5 day s. After the pre - incubation, the soils were treated at 10 ppm (based on the soi1 dry weight) with phenyl ring labeled [U 14 

### C] 2, 6 - dichloro - 4 - methyl phenol (ph - CH 3 

### ): radiochemical purity 100%, specific activity I 41.6 mCi /mMol, Sumitomo Che mical Company) dissolve in benzene: n - hexane (1:1), then returned t o the incubation chamber. Aliquots of the water 1ayer were collected through the si1icone disc using a micro sy ringe without opening the sample container at 0, 2. 5, 12, 19, 26, 33, and 54 day s post - treatment: aliquots of the headspace gas were collected using a gastight sy ringe at 0, 19, 26, 33, and 54 day s post - treatment. The water layer was fi1tered (0.5 μm) and anal yz ed b y reverse - phase - HPL C: the columns previously described were elute d with water: methanol gradient. The headspace gases were analyzed using GC equipped with thermal conductivity

detection. Results**167**



### Phenyl r in g - 1abeled [U 14 

### C] tolclofos methyl (O - 2,6 - dichloro - p - tolyl O,O - dimethyl phosphorothioate; radiochemical purity 99.5%3, at 16.5 ppm, degraded with **a** registrant calculated ha1f

- 1ife o f 31 day s (reviewer calculated for all data points= 47 day s) in an anaerobic sandy loam soil : water mixture that was incubated in the dark at 25 ± 1 oC for 364 day s. [ 14 

### C] tolclofos me thyl averaged 97.79% of the applied immediately post - treatment, 62.72% at 30 day s, 35.12%, at 59 day s, 19.22% at 92 day s, 5.15% at 120 day s, and <l . 07% at 364 day s (Tables XVII - 2 and XX - 2 of the report). Four degradates were identified in the soi1: water mixture: O - 2, 6 - dichloro - p - tolyl O - methyl O - hydrogen phosphorothioate ( **DM -**  **TM** ); 2, 6 - dichloro - 4 - methyl phenol ( **ph -**  **CH 3**  

### ); 4 - methylphenol ( **p -**  **cresol** ); and 2 - chl oro - 4 - methylphenol ( **DC -**  **ph -**  **CH 3**  

### ). **DM -**  **TM** , the major degradate, increased steadil y to a maximum average of 57.97% of the applied at 92 day s post - treatment (54.08 and 3.89% in the water and soil, respectivel y), and was 2.37% at 364 day s. **DC -**  **ph -**  **CH 3**  

### , averaged a maximum 10.18% of the applied at 30 days post treatment; **ph -**  **CH 3**  

### averaged a maximum 8.04% at 364 day s; and **p -**  **cresol** averaged a maximum of 4.67% at 14 day s. A t 1east 21 other [ 14 

### C] compounds were isolated from the soil or water; one of these I G - 1 (B - 1) averaged a maximum o f 1.71% o f the appl ied (0.07 ppm) in the water on day 120, and each of the remaining compounds averaged ≤1.0 6%. Evolved 14 

### CO and other [ 14 

### C] volatiles trapped by NaOH totaled 21.93 - 24.02% and 6.47 - 0.54% of the applied respectively, at 364 day s post - treatment (Table IV - 1). [ 14 

### C] volatiles trapped b y ethylene gl ycol totaled 1.22 - 1.29% of the applied at 364 day s post - treatment; and additional 0.19 - 0.20% was recovered from the walls of the sample container (Table X

– 1 of the study report). Un - extracted [ 14 

### C] residues averaged <5.0% of the applied through 120 day s post treatment; un - extracted [ 14 

### C] residues averaged 7.85 - 8.69% at 182 through 364 day s, during which time the ratio of fulvic acid to humic acid to humin ranged from 1:3.7: 1 to 1:6:l (TablesIV - 2and XXIII of the study report). The distribution of [ 14 

### C] residues between the soi1 and water fractions was approximately 1: 1 through 3 day s post - treatment, 1:3 at 62 through 120 day s, and 1: 1 at 364 days. Material balances were 95.00 - 99.55% of the applied through 30 day s po st - treatment, 77.52 - 96.42%) at 59 through 92 day s, and 41.69 - 69.59% at 120 through 364 days (Table IV - 1 of the study report). In an anci11ary

experiment in which an anaerobic sandy 1oam soil: water mixture was treated at 10 ppm with phenyl ring - labeled [ U 14 

### C] 6 - dichl oro - 4 - methyl phenol ( **ph -**  **CH 3**  

### ); radiochemical purity 100%) and incubated in the dark at 25 ± 1 oC, the study authors demonstrated that 14 

### CH4 

### , which was not trapped by either the ethylene glycol or NaOH solutions was a major degradate during th e anaerobic aquatic metabolism of tolclofos methyl , and its omission could account for the low material balance in the definitive experiment. At 364 day s post - treatment, 14 

### CH4 

### comprised 57.02% of the applied radioactivity (Table XX V II of the study report). **Adsorption/desorption** (MRID 422733 - 01) Study Classification**168**



### This study

was classified as supplemental for the data requirements of EPA Pesticide Assessment Guidelines, Subdivision N/Section 163 - on un - aged adsorption/desorption. The study was classifi ed as supplemental because concentrations of the amount of material adsorbed were obtained b y subtraction. Material and Methods To determine adsorption, duplicate 1 gram (dry weight) soil samples were shaken for 2 hours with 4, 10 ml test solutions of 0. 019, 0.037, 0.201 and 0.391 μg/ml at 25 ± 1°C. The soil/water was centrifuged and aliquots of the supernatant were anal yz ed b y LS C. The amount of material adsorbed was the amount of 14 

### C in the supernatant minus the applied. The soil/water was then extracte d and the soil residue was combusted to determine total radioactivity . To determine desorption, duplicate 1 gram (dry weight) soil samples were shaken 2 hours with 4, 10 ml test solutions of 0.019, 0.037, 0.201, and 0.391 μg/ml at 25 ± 1°C. After adsorption equilibrium took place (2 hours) 5 of the 10 mL were replaced with fresh 0.01 M CaCl 2 

### containing no test substance. Duplicate 1 mLaliquots were anal yz ed b y LSC. The soil/water suspensions were shaken for 1 hour to obtain the desorption equilibrium. Th e soil/water was then centrifuged and the supernatant was analyzed by LSC. The amount of material desorbed was the amount of 14 

### C in the soil at desorption equilibrium from the soil at the adsorption equilibrium. Results (1) The Freundlich coefficients for ads orption (Kd ads 

### ,)/(l/N ads 

### ) were 7.59/0.94, 25.17/0.95, 43.96/0.96, and 24.03/0.94 for the sandy loam soil (California), loamy sand soil (B 7), silty clay loam soil (F - 6) and the clay soil, respectivel y. The K oc 

### , adsorption constants were 1,649, 6,139, 3,209 , and 3,482 for the above soils respectivel y; (2) The Freundlich coefficients for desorption (Kddes 

### )/(l/N des 

### ) were 11.83/0.98, 26.97/0.91, 58.96/0.99, and 29.26/0.95 for the sandy loam soil (California), loamy sand soil (B 7), silty clay loam soil (F - 6) and the clay soil, respectivel y. The K oc 

### , desorption constants were 2,572, 6,578, 4,304, and 4,241for the above soils respectivel y; (3) The average recovery of the adsorption test sy stem was 90.9 to 105.7% of the applied. The average recovery

of desorption test sy stem was 90.6 to 104.1% of applied; (4) Little degradation of the test substance occurred during the adsorption/desorption experiment; 92.9 to 98.5% of the recovered 14 

### C was unchanged starting material; (5) The adsorption and desorption equilibrium were clearl y reached after 2 and 1 hour respectivel y; and (6) Less than 3% of the applied 14 

### C was adsorbed to the test vessel so no correction factor was introduced into any equation.**169**



### Study Classification This study

was classified as supplemental for the data req uirements of EPA Pesticide Assessment Guidelines, Subdivision N/Section 163 - on un - aged adsorption/desorption. The study was classified as supplemental because adsorbed amount was derived by subtraction, mass balance data were not reported (reported onl y f or one sample from each soil and was acceptable), desorption phase was not conducted, No anal ys is for transformation products was conducted for the samples but was conducted for the control which showed low degradation (degradation <5% of the applied in ad dition old data from previous study indicated that the level of transformation products was very

low). The adsorption/desorption characteristics of [U - phenyl 14 

### C] - labelled ( O - 2, 6 - dichloro - p - tol yl O,O - dimethyl phosphorothioate (tolclofos methyl; radioche mical purity >99.6%) were studied in two U.S. soils: a loam soil [pH 6.9, organic carbon 1.2%] and a sand soil [pH 6.1, organic carbon 0.64%], in a batch equilibrium experiment. The adsorption phase of the study was carried out by equilibrating air - dried, sieved soil with [ 14 

### C] tolclofos methyl at measured concentrations of 0.54, 0.11, 0.021, and 0.004 mg/kg for the loam soil and 0.63, 0.12, 0.021, and 0.004 mg/kg for the sand soil. The test soils were equilibrated at 25 ± 1oC for 6 hours in the dark. Th e equilibrating solution used was 0.01M CaCl 2 

### solution, with soil solution ratios of 1:15 (w: v) for the loam soil and 1:10 (w: v) for the sand soil. A desorption phase was not conducted. Following the adsorption phase, the supernatant solutions were separated by centrifugation and anal yz ed for radioactivity using L SC. The supernatant and soil samples were not anal yz ed for parent or transformation products. The experimental temperature emplo yed during the study was reported to be maintained at 25 ± 1 oC; supporting details were not provided. The pH of the loam soil - solution was 6.45 before incubation and 6.44 after incubation, and the pH of the sand soil remained at 5.55 before and after incubation. HPL C anal ys is of the control sample solution phase showed that tolclofos methyl was stable, with <5% degradation. Mass balances at the end of the adsorption phase were not reported, and could not be determined due to insufficient data. Mass balances determined for single samples of the loam soil treated at 0.54 and 0.021 ppm were 101.2 - 102.1% (20.5 - 27.4% in the adsorption supernatant extracts, 71.3 - 76.7% in the soil extracts, and 3.4 - 4% in the post - extracted solids). Mass balances determined for single samples of the sand soil treated at 0.63 and 0.021 ppm were 96.9 - 103.2% (25.8 - 34.0% in the adsorption supernatant extracts, 62.0 - 75.9% in the soil extracts, and 0.9 - 1.4% in the post - extracted solids). The percent of the applied tolclofos methyl residues that were adsorbed to the test soils could not be de termined from the available data. Using the Standardized Soil Mobility Classification Guidance according to the Food and Agriculture Organization (FAO) of the United Nations adopted by USEPA and using reviewer calculated adsorption Koc 

### values presented in Table 8 of this DER, tolclofos - methyl is characterized as being slightl y mobile in the loam and sand soils.**170**



### Adsorption **Results (No desorption step) Soil type:**  Loam Sand **Adsorption** Average Kd 52.27  10.86 26.92  6.84 Average Koc 4,284 4,206 Regression Kd 38.08 18.93 r2 0.9972 0.9963 p - value 3.30E - 10 9.28E - 10 Freundlich Regression Freundlich KF 32.39 16.26 p - value 7.36E - 11 8.83E - 09 r2 0.9996 0.9987 1/n 0.90 0.89 p - value 1.67E - 11 7.37E - 10 Freundlich KFoc 2,655 2,541 

### Adsorption/desorption (MRID 422733 - 01) Study Classification This study

was classified as supplemental for the data requirements of EPA Pesticide Assessment Guidelines, Subdivision N/Section 165 - 4 on bio - concentration in fish because the fish were not exposed to a constant concentration 

### of pesticide 

### and residues in the 

### water were not characterized. Materials and Methods Bluegill sunfish (

Lemnis macrochirus ; average length and weight of 47 mm and 3.4 g, respectivel y) were held in culture tanks on a 16 - hour daylight photo period for ≥14 day s prior to the initiation of the study . Flow - through aquatic exposure system was prepared using two 100 - L aquaria. Aerated well water was provided to each aquarium at a rate of 7.2 - 8.6 turnovers per day . The aquaria were immersed in a water bath and maintained at 22 ±2 °C. Bluegill sunfish (120) were placed in each aquarium, and one aquarium was continually treated with ring - labeled [ 14 

### C] tolclofos - methyl (radiochemical purity >99%, specific activity

7,700 dpm/μ g, Sumitomo Chemical Company) at 0.03 ppm. The second aquarium served as an untreated control. Following a 28 - day exposure period, the [ 14 

### C] tolclofos - methyl treated water was replaced with untreated water for a 14 - day depuration period. The treated water was s ampled prior to introducing the fish, and then water samples and fish (6, 15, or 25) were taken from the treated and control aquaria after 4 hours and 1, 3, 7, 14, 21, and 28 day s of exposure. During the depuration period, water samples and [ 14 

### C] tolclofos - methyl treated water and untreated fish were taken on day s 1, 3, 7, 10, and 14. Radioactivity

in the water samples was quantified using L SC. The detec tion limit was 0.0004 ppm.**171**



### Pooled samples (3 fish) of whole fish, edible tissues (body, muscle , kin, and skeleton) and non edible tissues (fins, head, internal organs) were homogenized with dry ice and anal yz ed for total radioactivity

using combustion and L SC. Reported recoveries of [ 14 

### C] residues from whole fish, edible tissues, and non - edible tis sues fortified with 0.55 μg of [ 14 

### C] tolclofos - methyl ranged from 95 to 101%. The detection limits for whole fish, edible tissues, and non - edible tissues were 0.021, 0.019, and 0.021 ppm, respectivel y. Additional samples of the edible and non - edible tissu es from day s 21 and 28 of the exposure period were separatel y homogenized with water, acidified to pH 1 with hydrochloric acid, and extracted three times with diethyl ether (MRID 00163642). Diethyl ether extracts were combined, dried over anhydrous sodium sulfate, and evaporated to dry ness. The remaining residue was dissolved in hexane: methylene dichloride (85:15) and passed through a gel filtration column (Bio - Beads S - X3). Ten 10 mL fractions were collected. Fractions 4 - 10 were combined, concentrated b y e vaporation and anal yz ed b y TLC on silica gel plates developed in toluene: acetic acid (91:13), toluene: ethyl acetate: formic acid (45:63:9), or toluene: ethyl acetate **:** isopropanol: acetic acid (32:48:20:12). Reference compounds were co - chromatographed with the samples and, following development, were visualized under UV light. Radioactive areas were detected b y autoradiography . Degradate characterizations were also confirmed by GC using electron - capture detection. The extracted fish tissue and remaining aq ueous phase (from diethyl ether extraction) were refluxed for 1 hour, and then extracted three times with ether. Ether extracts were combined, dried over anhydrous sodium sulfate, concentrated, and anal yz ed b y TL C, as described above. Un - extractable 14C r esidues remained in the fish tissue were quantified by

combustion and LS C. 

### Results Total 14C tolclofos - methyl residues accumulated in bluegill sunfish with maximum bio concentration factors of 120, I , 300, and 770x in edible tissues (body , muscle, skin, skeleton), non - edible tissues (fins, head, internal organs), an d whole fish, respect ively , during 28 days of exposure t o tolclofos - methyl residues **at** 0.012 - 0.037 ppm in a flow - through s ys tem (MRID 001 63641). Maximum levels of [14C] residues were 3.2 ppm in edible tissues, 36 **ppm** in non - edible tissues, and 20 ppm in whole fish. After 28 day s of exposure, tolclofos - methyl comprised 81.2 and 38.8% of the radioactivity in the edible and non - edible tissues, respectively . After 14 day s of depuration, [14C] residues in edible tissues, non - edible tissues, and whole fish were 0.043, 0.28, and 0. 18 ppm, respectively . Degradates detected in extracts from the edible and non - edible tissues include:

 

### O,O - dimethyl O **- (2,6**  **- dichloro**  **- 4**  **- formylphenyl) phosphorothioate (TM**  **- CHO);**   

### 3 ,5 - dichloro - 4 - hydroxybenzaldehyde ( **ph -**  **CHO** );  

### 3,5 - dichloro - 4 - hydroxy benzoic acid ( **ph -**  **COOH** );  

### O,O - dimethyl O - (2,6 - dichloro - 4 - methylphen yl ) phosphate ( **TMO** );  

### 3,5 - dichloro - 4 - hydroxy benzyl alcohol ( **ph -**  **CH 2**  

### OH ); and seven unknowns (MRID 00163642).**172**



### Independent **Laboratory Validations**  **(ILVs) for**  **the Environmental**  **Chemistry Method**  **for deter**  **mination of TM in soil** ( 48341916 and 488421 - 02 ) An anal yt ical method (Analy tical Procedure CLE 333/153 - 04R) was developed to detect and quantify residues of tolclofos - methyl in soil (Appendix 1, pp. 21 - 30). This study was conducted in accordance with Council Directive 91/414/EEC (1991) as amended b y C ommission Directive 96/46/EC (1996), EU Guidance documents SANCO/825/00, rev. 6 (2000) and SANCO/3029/99, rev. 4 (2000), and in compliance with United Kingdom GLP Regulations (1999) and OECD Principles of GLP ENV/MC/CHEM(98)17 (1998; p p. 2, 9). Untreated (control), sieved (2 - mm) soil (pH 4.9 - 5.5, organic matter 2.4%), characterized as a sandy loam (USDA), was obtained from Covance Laboratories Ltd. Environmental Fate Department and stored frozen ( - 20°C) prior to use (p. 10; Appendix 5, p. 41). Soil moisture content was determined prior to fortification (Appendix 1, p. 26). Aliquots (50 g) of soil were weighed into 500 - mLglass jars and fortified with tolclofos - methyl (purity 99.8%, Lot No.: 00404SG), in acet one, at 0.01 and 10.0 mg a.i./kg; five treated samples per fortification level (p. 11; Appendix 1, pp. 24, 26). Application solution volumes were 100 μL (5 μg a.i./mL) and 1 mL (500 μg a.i./mL) for the 0.01 and 10.0 mg a.i./kg test concentrations, respectively (p. 11). Two untreated soil samples were included as controls (Table 1, p. 17). Following fortification, water was added to yi eld a final volume of 100 mL , taking into account soil moisture content, and the sample allowed to stand 10 minutes (Appen dix 1, p. 26). The sample was then extracted once with acetone (200 mL) using mechanical shaking (interval not reported; Appendix 1, pp. 23, 26). Extract and soil were separated by filtration (No. 1 filter paper) via Buchner funnel. An aliquot of the extract was treated with sodium chloride (10:1, v:w), shaken, then partitioned once with methylene chloride. The resulting aqueous phase was discarded and the retained organic phase filtered through sodium sulphate. The separatory funnel and remaining filt er cake were rinsed twice with ethyl acetate and the rinses added to the organic phase. The sample was concentrated to near dry ness using rotary

evaporation (30°C), then taken to dry

ness under nitrogen. Residues were reconstituted in cyclohexane:ethyl ac etate (1:1, v:v), treated with sodium sulphate, decanted and an aliquot processed through gel permeation chromatography (GPC) under the following conditions: Bio - Beads S - X3 (200 - 400 mesh), eluant cyclohexane:ethyl acetate (1:1, v:v), flow rate 5.0 mL/minut e (Appendix 1, pp. 25 - 26). The collected fraction (retention time not reported) was taken to dry ness (rotary evaporation, 30°C). Residues were reconstituted in toluene for GC/MS analy sis with electron impact ionization in positive mode (EI + 

### ) and selected ion recording (SIR; Appendix 1, pp. 26 - 27). Three ions were monitored; 265 as the primary quantitation ion, 267 and 250 as confirmation ions. Retention time for tolclofos - methyl was ca . 10.0 minutes (Appendix 4, pp. 36 - 37, 39 - 40). 483 (p. 14). Q uantitation ion . Overall recovery averaged 98 ± 12.4% (mean ± RSD, range 82 - 124%, n = 10) of the applied (Tables 1 - 3, pp. 17 - 19). Per fortification level, recoveries averaged (n = 5) 95 ± 18.2% (82 - 124%) and 102 ± 2.5% (98 - 104%) at the 0.01 and 10 mg a.i ./kg test concentrations, respectivel y. Anal ys is of unfortified control soil detected minor levels of residues (0.0014 - 0.0028 mg/kg, <30% of LOQ) at the retention time of tolclofos - methyl, with no other significant interferences (Table 1, p. 17; Appendix 4, p. 38). Recoveries from fortified soil were corrected for mean residue level detected in the control samples (Table 1, p. 17). Detector responses for**173**



### tolclofos - methyl were linear (r2 

### = 0.997) over the range of 0.01 - 0.50 μg/mL (p. 13; Appendix 3, p. 33 ). Confirmation ions . Results for both confirmation ions satisfied the study author's criteria that all mean recoveries were within the range of 70 - 110% and RSD values were <20% (pp. 11 - 12, 14; Tables 2 - 3, pp. 18 - 19). **Environmental Chemistry Method for determination of TM in Water** ( 483419 - 17 and 488421 - 01 ) Multi - residue method F12 (Deutsche Einheitsverfahren zur Wasser- , Abwasser - und Schlammuntersuchung) of EU Guidance document SANCO/825/00 was used to detect and quantify residues of tolclofos - methyl in water (pp. 12, 17). This study was conducted in accordance with Commission Directive 96/46/EC (1996), EU Guidance documents SANCO/825/00, rev. 6 (2000) and SANCO/3029/99, rev. 4 (2000), and in compliance with Swiss GLP Ordinance RS 813.016.5 (2000; p p. 3, 10). Aliquots (1 L) of drinking (tap) water (pH 7.00, DOC 6.9 mg C/L) were fortified with tolclofos - methyl (purity 99.8%, L ot No.: 00404SG), in acetone, at 0.1 and 1.0 μg/L; five treated samples per fortification leve l (pp. 13 - 14, 16, 21; Appendix I , p. 38). Application solution volumes were 100 μL at both fortification levels, with a final co - solvent (acetone) concentration of 0.01% (p. 16). Two untreated water samples were included as controls (Table 1, p. 23). Each water sample was applied (flow rate 5 - 10 mL/minute) to a C18 solid phase extraction (SPE) cartridge (Mega bond Elut, 2 g/12 mL) pre conditioned with methanol and water (pp. 15, 17). The loaded SPE cartridge was dried under vacuum 1 - 2 minutes, then tolc lofos - methyl was eluted (flow rate 5 - 10 mL/minute) with two volumes (10 mLx 2) of methylene chloride. Eluates were combined and filtered over anhydrous sodium sulphate, with the remaining filter cake then rinsed with methyl ene chloride. The sample was c oncentrated to near dry ness using rotary

evaporation (30 - 40°C), then taken to dry ness under nitrogen. Residues were reconstituted in toluene for GC anal ys is with flame photometric detection (FPD, P - mode; pp. 17 - 18). GC retention time for tolclofos - methyl was ca . 13.1 minutes (p. 18; Figures 1 - 2, pp. 26 - 27; Figures 4 - 5, pp. 29 - 30). As a confirmatory method, selected samples were analyzed by GC/MS with electron impact ionization in negative mode (EI - 

### ), full - scan and selected ion monitoring (SIM; pp. 19, 22 ). GC/MS retention time for tolclofos methyl was ca . 11.2 minutes (p. 19; Figures 6 - 7, pp. 31 - 32; Figures 9 - 11, pp. 34 - 36). For both anal yt ical methods, the limit of detection (LOD) for tolclofos - methyl was estimated at ca . 0.01μg/mL , based on lowest cal ibration standard, and the limit of quantitation (L OQ) established at 0.1 μg/L (pp. 21 - 22). Primary GC anal ys is . Overall recovery averaged 90.8 ± 5.8% (mean ± RSD, range 81.8 - 100.1%, n = 10) of the applied (p. 21; Tables 1 - 2, p. 23; DER Attachment 2). P er fortification level, recoveries averaged (n = 5) 87.7 ± 4.8% (81.8 - 93.4%) and 93.8 ± 4.8% (89.1 - 100.1%) at the 0.1 and 1.0 μg a.i./L test concentrations, respectivel y. Analysis of unfortified control water found no interferences at the retention time o f tolclofos - methyl (Figure 3, p. 28). Correlation of detector responses for tolclofos - methyl was determined using a non - linear function (r2 

### = 0.998) due to the range of the calibration curve at 0.01 - 1.0 μg/mL(p. 21; Table 3, p. 24).**174**



### Confirmatory

GC/MS analy sis . Results for tolclofos - methyl in drinking (tap) water using GC/MS analy sis were consistent with those determined by the primary

GC analy sis method (p. 22; Table 1, p. 23; Table 4, p. 25; Figure 8, p. 33). **Independent Laboratory Validations (ILV s) for the Environmental Chemistry Method for**  **determination of TM in Water** ( 483419 - 18 and 488421 - 03 ) Multi - residue method F12 (Deutsche Einheitsverfahren zur Wasser- , Abwasser - und Schlammuntersuchung) of EU Guidance document SANCO/825/00 was used to dete ct and quantify residues of tolclofos - methyl in water (pp. 12, 17). This study was conducted in accordance with Commission Directive 96/46/EC (1996), EU Guidance documents SANCO/825/00, rev. 6 (2000) and SANCO/3029/99, rev. 4 (2000), and in compliance with Swiss GLP Ordinance RS 813.016.5 (2000; p p. 3, 10). Aliquots (1 L) of surface (river) water (pH 7.54, DOC and TOC 8.2 mg C/L) were fortified with tolclofos - methyl (purity 99.8%, Lot No.: 00404SG), in acetone, at 0.1 and 1.0 μg/L ; five treated samples pe r fortification level (pp. 13 - 14, 16, 21; Appendix I, p. 38). Application solution volumes were 100 μLat both fortification levels, with a final co - solvent (acetone) concentration of 0.01% (p. 16). Two untreated water samples were included as controls ( Table 1, p. 23). Each water sample was applied (flow rate 5 - 10 mL/minute) to a C18 solid phase extraction (SPE) cartridge (Mega bond Elut, 2 g/12 mL) pre - conditioned with methanol and water (pp. 15, 17). The loaded SPE cartridge was dried under vacuum 1 - 2 minutes, then tolclofos - methyl was eluted (flow rate 5 - 10 mL/minute) with two volumes (10 mLx 2) of methylene chloride. Eluates were combined and filtered over anh ydrous sodium sulphate, with the remaining filter cake then rinsed with methylene chlorid e. The sample was concentrated to near dry ness using rotary

evaporation (30 - 40°C), then taken to dry

ness under nitrogen. Residues were reconstituted in toluene for GC anal ys is with flame photometric detection (FPD, P - mode; pp. 17 - 18). GC retention time for tolclofos - methyl was ca . 13.1 minutes (p. 18; Figures 1 - 2, pp. 26 - 27; Figures 4 - 5, pp. 29 - 30). As a confirmatory

method, selected samples were analy zed by GC/MS with electron impact ionization in negative mode (EI - 

### ), full - scan and selected ion monitoring (SIM; pp. 19, 22). GC/MS retention time for tolclofos - methyl was ca . 11.2 minutes (p. 19; Figures 6 - 7, pp. 31 - 32; Figures 9 - 11, pp. 34 - 36). For both analy tical methods, the limit of detection (LOD) for tolclofos - methyl was estimated at ca . 0.01μg/mL , based on lowest calibration standard, and the limit of quantitation (LOQ) established at 0.1 μg/L (pp. 21 - 22). Primary GC anal ys is . Overall recovery averaged 94.4 ± 10.3% (mean ± RSD, range 82.1 - 107.4%, n = 10) of the applied (p. 21; Tables 1 - 2, p. 23; DER Attachment 2). Per fortification level, recoveries averaged (n = 5) 85.7 ± 4.2% (82.1 - 90.1%) and 103.1 ± 2.8% (100.4 - 107.4%) at the 0.1 and 1.0 μg a.i./Ltest concentrations, respectively . Anal ys is of unfortified control water found no interferences at the retention time of tolclofos - methyl (Figure 3, p. 28). Correlation of detector responses for tolclofos - methyl was determined using a non - linear function (r2 

### = 0.9968) due to the range of the calibration curve at 0.01 - 1.0 μg/mL(p. 21; Table 3, p. 24 ). Confirmatory

GC/MS analy sis . Results for tolclofos - methyl in surface (river) water using GC/MS analy sis were consistent with those determined by the primary

GC analy sis method (p.**175**



### 22; Table 1, p. 23; Table 4, p. 25; Figure 8, p. 33). **II. Detailed Fate**  **Properties Table** Detailed fate properties table for TM in biotic systems Detailed fate properties table for TM in biotic systems 

### (1) Aerobic soil metabolism **Property /**  **Description or Value (a)**  **MRID 001561 -**  **06 “Supplemental”; Two Soils (Viable & Sterilized)**  **Viable Soil 1 t1⁄2= 48 days**  **(t1⁄2= 239 days TTR) Major degradates:**  **CO 2**  **:** max= 17.0% @ 90 d **DM -**  **TM :**  max= 11.0% @ 60 d declined to 3.7% @ 180 d **Minor degradates: DM**  **- TM**  **O:** max= 3.4% @ 180 d **ph -**  **CH 3**  **:** max= 3.9 - 4.1% @ 60 - 180 d with no apparent decline **TM O:**  max= 0.9 - 1.3% @ 60 - 180 d with no apparent decline **TM -**  **CH 2**  **OH; TM -**  **COOH; TMO -**  **CH 2**  **OH; TMO -**  **COOH; ph**   ** CH** **2 OH; ph**  **- COOH:**  max= 0.3 - 0.4% each @ 60 - 180 d **Unidentified:** max= 4.6% @ 60 - 120 d decli ned to 4.0% @ 180 d **Others: Organic volatiles:**  19.6% @ 180 d **Bound residues:** max 53.4% @ 120 d declined 50.8% @ 180 d **Sterilized Soil 1 t1⁄2= 80**  days **(t1⁄2 was not calculated for the TTR) Major degradates:**  None **Minor degradates: DM**  **- TM**  **:** max= 0.4% @ 30 d **DM -**  **TM O:**  max= 0.8% @ 60 d **ph -**  **CH 3**  **:** max= 3.1% @ 30 d **TM O:**  max= 0.2% @ 30 d **TM -**  **CH 2**  **OH; TM -**  **COOH; TMO -**  **CH 2**  **OH; TMO**   ** COOH; ph** **- COOH:**  max= 0.1 - 0.2% each @ 30 d **CO 2**  **:** max= <0.1% @ 30 d **TM O**  **- COOH & ph**  **- CH**  **2 OH:**  <1% throughout **Unidentified:** max= 2.0% @ 30 d **Others: Organic volatiles:**  0.2% @ 30 d **Bound residues:** max 19.1% @ 30 d**176**

**Viable Soil 2 t1⁄2= 44**  days **(210 days TTR) Major degradates:**  **CO 2**  **:** max= 22.9% @ 90 d **Minor degradates: DM**  **- TM**  **:** max= 4.9% @ 90 d declined to 0.9% @ 180 d **DM -**  **TM O:**  max= 1.8% @ 14 d declined to 0.9% @ 180 d **ph -**  **CH 3**  **:** max= 2.6% @ 14 - 90 d declined to 0.9% @ 180 d **TM O:**  max= 0.6% @ 90 d declined to 0.3% @ 180 d **TM -**  **CH 2**  **OH; TM -**  **COOH; TMO -**  **CH 2**  **OH; TM**  **O -**  **COOH; ph**   ** CH** **2 OH; ph**  **- COOH:**  max= 0.2 - 0.4% each @ 14 - 120 d declined to 0.3 - <0.1% @ 180 d **Unidentified:** max= 3.3% @ 180 d **Others: Organic volatiles:**  28.6% @ 180 d **Bound residues:** max 46.6 - 47.0% @ 120 - 180 d **Sterilized Soil 2 t1⁄2= 116**  days **(t1⁄2 was not calculated for the TTR)**  **Major degradates:** None **Minor degradates: DM**  **- TM**  **:** max= 2.1% @ 30 d **DM -**  **TM O:**  max= 0.4% @ 30 d **ph -**  **CH 3**  **:** max= 2.8% @ 30 d **TM O:**  max= 0.2% @ 30 d **TM -**  **CH 2**  **OH; TM -**  **COOH; TMO -**  **CH 2**  **OH; TMO**   ** COOH; ph** **- COOH:**  max= 0.1 - 0.2% each @ 30 d **CO 2**  **:** max= <0.1% @ 30 d **TM O**  **- COOH & ph**  **- CH**  **2 OH:**  <1% throughout **Unidentified:** max= 1.7% @ 30 d **Others: Organic volatiles:**  0.4% @ 30 d **Bound residues:** max 11.0% @ 30 d

**(b) MRID 427032**  **- 01 “Acceptable”**  **Soil 3: t1⁄2= 79** days (Parent Alone); **t1⁄2= 161** days (TTR) **Major degradates: DM**  **- TM**  **:** max= 18.5% @ 90 d declined to % 0.7% @ 365 d ( **t1⁄2= 56.7** days) **CO 2**  **:** max= 33.3% @ 365 d **Minor degradates: ph**  **- CH3:**  max= 2.8% @ 121 d declined to % 1.4% @ 365 d Oxidized, hydroxyl ated or methylated forms of the methyl ring (26 degradates)= 3.6% @ 271 d declining to 2.7% @ 365 d (identified degradates included: **DM -**  **TMO -**  **COOH; DM -**  **TMO; TMO -**  **COOH, SM -**  **TM ;**  and **ph -**  **COOH Others:**  **Organic volatiles:** A total of 26% @ 365 d (18% **Parent** , 6% **ME -**  **ph -**  **CH 3**  and 2% **ph -**  **CH 3**  ) **Bound residues:** max 21.0% @ 271 d declining to % 19.0% @ 365 d **(c) MRID 483419**  **- 23 supplemented by 483419**  **- 25 “**  **Supplemental ”** 

**Experimental duration:** 112 days @ 1 0 o C **Soil 4 Soil 5**  **Soil 6 t1⁄2= 28**  days; **t1⁄2= 116** days (TTR) **t1⁄2= 23** days; **t1⁄2= 169**  days (TTR) **t1⁄2= 31** days; **t1⁄2= 165** days (TTR) **Major degradates: CO**  **2 :**  max= 45.7% @ 90 d **Major degradates: CO**  **2 :**  max= 27.3% @ 112 d **Major degradates: CO**  **2 :**  max= 20.4% @ 112 d**177**

**Minor degradates (d= days;** ND **= No Detection): DM**  **- TM**  **:** max= 0.50% @ 28 d declined ND @ 112 d **ph -**  **CH 2**  **OH:** max= 0.29% @ 28 d declined ND @ 112 d **ph -**  **COOH:** max= 0.77% @ 28 d declined to ND @112 d **TM -**  **COOH:** max= 1.67% @ 7 d declined to 0.23% @ 112 d **TM O:**  max= 0.37% @ 28 d declined to ND @ 112 d **DM -**  **TM O:**  max= 0.19% @ 7 d declined to ND @ 112 d **Unknowns:** max= 2.62% @ 7 d declined to 1.11% @ 112 d **Minor degradates Not identified:**  max= 6.7% @ 14 d declined to 3.0% @ 112 d **Unknowns:** max= 2.9% @ 7 d declined to 0.03% @ 112 d **Minor degradates Not identified:**  max= 12.2% @ 55 d declined to 9.3% @ 112 d **Unknowns:** max= 3.9% @ 7 d declined to 0.15% @ 112 d **Others: Bound Residues:**  max= 44.0% @ 84 d declined to 41.9% @ 112 d **Volatiles:** max= 0.22% @ 112 d **Others:** max= 61.0% @ 84 d declined to 54.5% @ 112 d max= 0.21% @ 112 d **Others:** max= 52.2% @ 112 d max= 0.22% @ 112 d

**(d) MRID 483419**  **- 22: Test Substance: DM**  **- TM**  **(The m ajor TM degradate) “Acceptable”** 

**Experimental duration:** 7 days @ 20 o C (Application rate 0.26 ppm) **Soil 8 Soil 11**  **Soil 12 t1⁄2= 1.18**  days (28.3 hours) **t1⁄2= 0.55** days (13.2 hours) **t1⁄2= 0.26** days (6.3 hours)**178**

**Major degradates: ph**  **- CH**  **3 :**  max= 15.2% @ 0 d declined 0.6% @ 7 d **CO 2**  **:** max= 18.9% @ 7 d **Minor degradates (** 

ND **= No Detection): DM**  **- TM**  **O:** max= 8.6% @ 0 d declined 0.1% @ 7 d **ph -**  **COOH:** max= 0.2% @ 0.3 d declined to ND @ 7 d **Unknowns:** max= 3.2% @ 0d declined to 2.5% @ 7 d **Others: Bound Residues:**  max= 73.6% @ 3 d declined to 73.2% @ 7 d **Organic volatiles:** Not detected **Major degradates: ph**  **- CH**  **3 :**  max= 13.2% @ 0 d declined 0.5% @ 7 d **CO 2**  **:** max= 22.8% @ 7 d **Minor degradates (**

ND **= No Detection): DM**  **- TM**  **O:** max= 5.7% @ 0 d declined 0.5% @ 7 d **ph -**  **COOH:** max= 0.3% @ 0 d declined to ND @ 7 d **Unknowns:** max= 2.6% @ 0 d declined to 1.4 @ 7 d **Others: Bound Residues:**  max= 78.6% @ 3 d declined to 68.6% @ 7 d **Organic volatiles:** Not detected **Major degradates: ph**  **- CH**  **3 :**  max= 11.8% @ 0 d declined 1.4% @ 7 d **CO 2**  **:** max= 19.9% @ 7 d **Minor degradates (**

ND **= No Detection): DM**  **- TM**  **O:** max= 8.3% @ 0.3 d declined ND @ 7 d **ph -**  **COOH:** max= 1.0% @ 0.3 d declined to ND @ 7 d **Unknowns:** max= 3.6% @ 0d declined to 2.0% @ 7 d **Others: Bound Residues:**  max= 81.0% @ 0.7 d declined to 76.4% @ 7 d **Organic volatiles:** Not detected **(e) MRID 483419**  **- 24 “Acceptable”**  **Experimental duration:** 90 days @ 20 o C (Application rate 2 ppm= equivalent to 4.1 lbs a.i/A to a depth of 6”) **Parent Alone: t1⁄2= 17** days in **Soil 7** ; **t1⁄2= 16** days in **Soil 8** ; **t1⁄2= 16** days in **Soil 9** ; and **t1⁄2= 17** days in **Soil 10 TTR: t1⁄2= 139**  days in **Soil 7** ; **t1⁄2= 128** days in **Soil 8** ; **t1⁄2= 114** days in **Soil 9** ; and **t1⁄2= 98** days in **Soil 10 179** 

**Major degradates: CO**  **2 :**  **Soil 7** : max= 36 .9% @ 90 d; S **oil 8** : max= 40.9% @ 90 d; **Soil 9** : max= 39.6% @ 90 d; **Soil 10** : max= 42.6% @ 90 d **DM -**  **TM :**  **Soil 8** : max= 13.3% @ 3 d declined non - detection @ 30 d **Minor degradates: DM**  **- TM**  **: Soil 7**  : max= 1.1% @ 1 d declined to non - detection @ 15 d; **Soil 9** : max= 3.6% @ 7 d declined non - detection @ 30 d;

**Soil 10** : max= 0.6% @ 15 d declined non - detection @ 30 d **ph -**  **CH3: Soil 7**  : max= 1.3% @ 3 d declined to % 0.1% @ 90 d; **Soil 8** : max= 8.0% @ 3 d declined to % 0.5% @ 90 d;

**Soil 9** : max= 2.9% @ 7 d declined to % 0.1% @ 90 d; **Soil 10** : max= 4.1% @ 7 d declined to % 1.4% @ 90 d **Others: Bound Residues:**  **Soil 7** : max= 63.6% @ 30 d declined to % 56.1 @ 90 d; **Soil 8** : max= 60.2% @ 15 d declined to 49.0% @ 90 d; **Soil 9** : max= 55.9% @ 15 d declined to % 52.6% @ 90 d; **Soil 10** : max= 48.9% @ 30 d declined to 45.4% @ 90 d **Organic volatiles: In all soils:** A total of 0.2 to 0.4% @ varied times from 3 to 90 d **Unknowns and Un -**  **resolved: In all soils:** max= 1.9% @ 3 d**180** 

### (2) **Aerobic and anaerobic soil MRID**  **428183 -**  **01 “Acceptable”** This study was conducted for 92 days @ 25 o C (32 days in aerobic conditions followed by 60 days in anaerobic conditions. Application rate 16 ppm= equivalent to 32 lbs a.i/A to a depth of 6”). **Property /**  **Description or Value Aerobic phase (Incubated for 32 days)**  **t1⁄2= 53** days ( **Soil 3); Bound Residues are low Anaerobic phase (Incubated for 60 days following the aerobic**  **phase) t1⁄2= 87**  days ( **Soil 3); Bound Residues are low Major degradates:**  **DM -**  **TM :**  max= 12.6% @ 32 d **Minor degradates: ph**  **- CH3:**  max= 4.1% @ 21 d declined to 2% at 32 d **CO 2**  **:** max= 4.1% @ 32 d **Many degradates:** <0.8% including: **DM -**  **TM O**  **** **COOH; TMO; DM -**  **TM O;**  **TM -**  **COOH, SM -**  **TM ; ph**  **- COOH; ph**  **- CH**  **2 OH**  **Others: Volatiles:**  A total of 2.5% @ 32 d (mostly Parent) **Bound residues:** 2.5% @ 32 d **Major degradates: DM**  **- TM**  **:** max= 31.2% @ 60 d **Minor degradates: ph**  **- CH**  **3 :**  max= 8.0% @ 42 d declining to % 2.9% @ 60 d **CO 2**  **:** max= 3.3% @ 60 d; **ph -**  **Cresol:** max= 5.1% @ 60 d **Many degradates:** <0.8% including: **DM -**  **TM O**  **- COOH; TMO;**  **DM -**  **TM O; TM**  **- COOH, SM**  **- TM**  **; ph -**  **COOH; ph -**  **CH 2**  **OH; DC**   ** ph** **- CH**  **3 + 4 other unidentified degradates**  **Others: Volatiles:**  A total of 5.1% @ 60 d (2.7% Parent) **Bound residues:** 4.1% @ 60 d 

### (3) Anaerobic soil **Property /**  **Description or Value MRID 001561**  **- 06 “Supplemental”**  **Parent Alone: t1⁄2= 36** days **in Soil 1 TTR: t1⁄2= 107**  days **Parent Alone: t1⁄2= 57** days **in Soil 2 TTR: t1⁄2= 161**  days**181**

**Major degradates:** None **Minor degradates: CO**  **2 :**  max= 0.3% @ 60 d **DM -**  **TM :**  max= 7.7% @ 60 d **DM -**  **TM O:**  max= 2.5% @ 60 d **ph -**  **CH 3**  **:** max= 3.7% @ 60 d **TM O:**  max= 1.9% @ 60 d **TM -**  **CH 2**  **OH; TM -**  **COOH; TMO -**  **CH 2**  **OH; ph -**  **CH 2**  **OH; ph**  **- COOH:**  max= 0.2 - 0.6% each @ 60 d **TM O**  **- COOH:**  <1% throughout **Unidentified:** max= 4.6% @ 60 d **Others: Organic volatiles:**  0.6% @ 60 d **Bound residues:** max 39.0% @ 60 d **Major degradates:** None **Minor degradates: CO**  **2 :**  max= 0.9% @ 60 d **DM -**  **TM :**  max= 6.7% @ 30 d declined to 4.8% @ 60 d **DM -**  **TM O:**  max= 1.0 - 1.1% @ 30 - 60 d **ph -**  **CH 3**  **:** max= 2.6 - 2.7% @ 14 - 60 d **TM O:**  max= 1.9% @ 60 d **TM -**  **CH 2**  **OH; TM -**  **COOH; TMO -**  **CH 2**  **OH; ph -**  **CH 2**  **OH; ph**   ** COOH:** max= 0.2 - 0.7% each, mostly @ 60 d **TM O**  **- COOH:**  max= 0.2% @ 60 d **Unidentified:** max= 2.6% @ 60 d **Others: Organic volatiles:**  1.1% @ 60 d **Bound residues:** max 31.0% @ 30 - 60 d**182** 

### ( **4 ) Aerobic aquatic (Two; water: sediment systems)**  **MRID 483419 -**  **26 “Acceptable” Systems:**  TM applied at a rate of 0.67 ppm to pond/lake water: sediment systems and incubated for 100 days @ 20 o C. **Property /**  **Description or Value (a) Total System** **1 t1⁄2= 19**  days (parent alone); **t1⁄2= 49** days (TTR) **Major degradates: DM**  **- TM**  **:** max= 23.5% @ 30 d declined to no detect @100 d **CO 2**  **:** max= 52.5% @ 100 d **Minor degradates : ph**  **- CH**  **3 :**  max= 6.5% @ 30 d declined to 1.1% @100 d **DM -**  **TM O:**  max= 2.9% @ 62 d declined to no detect @100 d **TM -**  **COOH:** max= 0.2% @ 3 - 7 d declined to no det ect @100 d **Unknowns:** max= 2.2% @ 100 d **Others : Volatiles:**  A total of 12.7 to 11.6 @ 62 - 100 d (Parent >95%) **Bound residues:** 25.9% @ 62 d declined to 20.4% @100 d **(a) Total System 2**  **t1⁄2= 26** days; **t1⁄2= 65** day s (TTR) **Major degradates : DM**  **- TM**  **:** max= 13.4% @ 30 d declined to 4.9% at 100 d **CO 2**  **:** max= 35.6% @ 100 d **Minor degradates : ph**  **- CH**  **3 :**  max= 2.6% @30 d declined to 0.9% at 100 d **DM -**  **TM O:**  max= 5.4% @30 d declined to 0.7% at 100 d **TM -**  **COOH:** max= 0.9% @7 d declined to no detect @100 d **Unknowns:** max= 1.2% @30 d declined to 0.5% at 100 d **Others : Volatiles:**  A total of 21.8% @ 100 d (Parent >95%) **Bound residues** : 35.0% @76 d declined to 19.9% @100 d**183**

**(b) Water (System s 1 & 2)**  **(Systems 1) Major degradates :**  **DM -**  **TM :**  max= 10.7 @30 d declined to no detect @100 d **Minor degradates : ph**  **- CH**  **3 :**  max= 0.5% @30 d declined to no detect @100 d **DM -**  **TM O:**  max= 2.9% @62 d declined to no detect @100 d **TM -**  **COOH:** max= Not detected **Unknowns:** max= 0.6 - 0.7% @1 and 100 d, No clear pattern **(Systems 2) Major degradates :**  None **Minor degradates : DM**  **- TM**  **:** max= 9.2% @62 d declined to 3.0% @100 d **ph -**  **CH 3**  **:** max= 1.0% @30 d declined to no detect @100 d **DM -**  **TM O:**  max= 5.4% @30 d declined to 0.7% @100 d **TM -**  **COOH:** max= 0.9% @ 7 d declined to no detect @100 d **Unknowns:** max= 1.2% @ application declined to no detect @100 d **(c) Sediment (Systems 1 & 2) (Systems 1)**  **Major degradates : DM**  **- TM**  **:** max= 12.7% @30 d declined no detect @100 d **Minor degradates : ph**  **- CH**  **3 :**  max= 6.0% @30 d declined to 1.1 at 100 d **DM -**  **TM O:**  max= Not detected **TM -**  **COOH:** max= 0.2% @7 d declined to no detect @100 d **Unknowns:** max= 1.6% @100 d **(Systems 2) Major d**  **egradates :** None **Minor degradates : DM**  **- TM**  **:** max= 4.5% @30 d declined to 1.9% @100 d **ph -**  **CH 3**  **:** max= 1.6% @30 d declined to 0.9% at 100 d **DM -**  **TM O:**  max= Not detected **TM -**  **COOH:** max= Not detected **Unknowns:** max= 0.9% @1 d declined to 0.2% @ 100 d**184** 

### (5 **) Anaerobic aquatic Half -**  **lives (one soil: water system) MRID 431281**  **- 01 “Acceptable”**  **Important Note:** Recovery of radiocarbon was more than 96% of the applied dose from Day 0 to Day 30, but decreased to 55% at Day 364 due to production of 14 C - methane which could not be trapped by NaOH and ethylene glycol solutions. Production of 14 CH 4 from 14 Cph - CH 3 (2,6 - Di chloro - 4 - methylphenol) under the same anaerobic aquatic soil conditions was confirmed in a separate study **Property /**  **Description or Value (a) Total System** **3 t1⁄2= 47**  days (parent alone); **t1⁄2= 95** days (TTR) **Major degradates : DM**  **- TM**  **:** max= 58.0% @ 92 d declined to 2.4% @ 364 d **DC -**  **ph -**  **CH 3:**  max= 10.2% @ 30 d declined to 1.8 % @ 364 d **CO 2**  **:** max= 23.5% @ 364 d **Minor degradates : ph**  **- CH**  **3 :**  max= 8.1% @ 364 d **p -**  **Cresol:** max= 4.7 % @ 14 d declined to < 0.1% @ 364 d **Other degradates:** 5.7% @ 364 d **Others : Volatiles:**  A total of 1.5% @ 282 - 364 days **CH 4**  **:** max= 57.0% @ 364 d **Bound residues:** 8.7% @ 364 days **(b) Water (system 3)**  **Major degradates : DM**  **- TM**  **:** max= 54.1% @ 92 d declined to 1.2% @ 364 d **Minor degradates : DC**  **- ph**  **- CH**  **3:** max= 8.2% @ 30 d declined to 1.3 % @ 364 d **ph -**  **CH 3**  **:** max= 6.8% @ 364 d **p -**  **Cresol:** max= 3.9% @ 14 d declined to <0.1% @ 364 d **Other degradates:** 4.4 - 4.0% @ 282 - 364 d **(c) Soil (system 3)**  **Major degradates :** None **Minor degradates : DM**  **- TM**  **:** max= 4.6% @ 62 d declined to 1.2% @ 364 d **DC -**  **ph -**  **CH 3:**  max= 2.0% @ 30 d declined to 0.5 % @ 364 d **ph -**  **CH 3**  **:** max= 1.2% @ 364 d **p -**  **Cresol:** max= 0.8% @ 14 d declined to < 0.1% @ 364 d **Other degradates:** 1.9% @ 364 d**185**



## A **PPENDIX** 

## H. **R ESULTS FROM**  

## STIR **AND** 

## SIP **S CREENING**  

## T **OOLS 186** 



# Screening Tool for Inhalation Risk (STIR) **Input Ap**  **plication and Chemical Information** Enter Chemical Name Tolclofos methyl Enter Chemical Use seed treatment Is the Application a Spray? (enter y or n) n If Spray W hat T yp e (enter ground or air) ground Enter Chemical Molecular W eight (g/m ole) 301.12 Enter Chemical Vapor Pressure (mmHg) 1.38E - 05 Enter Application Rate (lb a.i./acre) 0.02 **Toxicity Properties Bird**  Enter Lowest Bird Oral LD 50 (m g/kg bw) 2000 (>2000 mg kg/bw for finch) Enter Mineau Scaling Factor Enter Tested Bird We ight (kg) 0.012 **Mammal** Enter Lowest Rat Oral LD 50 (m g/kg bw) 5000 (> 5000 mg/kg bw for rat) Enter Lowest Rat Inhalation LC 50 (mg/L) 1.9 Duration of Rat Inhalation Study (hrs) 4 Enter Rat W eight (kg) 0.225 

## Output **Results A**

**vian (0.020 kg )** Maximum Vapor Concentration in Air at Saturation (m g/m 3 ) 2.24E - 01 Maximum 1 - hour Vapor Inhalation Dose (mg/kg) 2.81E - 02 Adjusted Inhalation LD 50 5.49E+00 Ratio of Vapor Dose to Adjusted Inhalation LD 50 5.12E - 03 **Exposure not Likely Significant** Maximum Post - treatment Spray Inhalation Dose (m g/k g) not applicable Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 not applicable **not applicable** 

### Results Mammalian (0.015 kg ) Maximum Vapor Concentration in Air at Saturation (m g/m 3 ) 2.24E - 01 Maximum 1 - hour Vapor Inhalation Dose (mg/kg) 3.53E - 02 Adjusted Inhalation LD 50 1.58E+02 Ratio of Vapor Dose to Adjusted Inhalation LD 50 2.24E - 04 **Exposure not Likely Significant** Maximum Post - treatment Spray Inhalation Dose (m g/k g) not applicable Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 not applicable **not applicable 187** 

**Results of STIR Modeling for TM Table 1. Inputs**  **Parameter Value**  Chemical name Tolclofos methyl Solubility (in water at 25 o C; mg/L) 0.7 Mammalian LD 50 (mg/kg - bw) 3500 (m ouse) Mammalian test species other Bod y weight (g) of "other" mammalian species 20 Mammalian NOAEL (mg/kg - bw) 12.2 (m ouse) Mammalian test species other Bod y weight (g) of "other" mammalian species 20 Avian LD 50 (mg/kg - bw) 2000 (finch) Avian test species other Bod y weight (g) of "other" avian species 12 Mineau scaling factor 1.15 Mallard NOAEC (mg/kg - diet) 500 Bobwhite quail NOAEC (mg/kg - diet) 500 NOAEC (mg/kg - diet) for other bird species Bod y weight (g) of other avian species NOAEC (mg/kg - diet) for 2nd other bird species Bod y weight (g) of 2nd other avian species **Table 2. Mammalian Results Parameter**  **Acute Chronic**  Upper bound exposure (mg/kg - bw) 0.1204 0.1204 Adjusted toxicity value (mg/kg - bw) 1316.2111 4.5879 Ratio of exposure to toxicity 0.0001 0.0262 Conclusion* **Drinking water exposure alone is NOT a potential**  **concern for mammals Drinking water exposure**  **alone is NOT a potential concern for mammals**  **Table 3. Av**  **ian Results Parameter**  **Acute Chronic**  Upper bound exposure (mg/kg - bw) 0.5670 0.5670 Adjusted toxicity value (mg/kg - bw) 2159.2718 24.8063 Ratio of exposure to acute toxicity 0.0003 0.0229 Conclusion* **Drinking water exposure alone is NOT a potential**  **concern for birds Drinking water exposure**  **alone is NOT a potential concern for birds**  *Conclusion is for drinking water exposure alone. This does not combine all routes of exposure. Therefore, when aggregated with other routes ( i.e ., diet, inhalation, dermal), pesticide exposure through drinking water may contribute to a total exposure that has potential for effects to non - target animals.**188**