### 1 OFFICE OF CHEMICAL SAFETY
AND POLLUTION PREVENTION 

### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON

, D.C. 20460

Date: December 3, 2014

PC Codes: 108800, 108801

DP Barcode: 420467

MEMORANDUM

SUBJECT: Registration Review Problem Formulat ion for Metolachlor and S-Metolachlor

FROM: Robin Sternberg, Ph.D., Wildlife Biologist Christopher M. Koper, M.S., Chemist

Environmental Risk Branch 1

Environmental Fate and Effects Division (7507P)

THROUGH: Sujatha Sankula, Ph.D., Branch Chief Meghan Radtke, Ph.D., Acting RAPL

Environmental Risk Branch 1

Environmental Fate a nd Effects Division (7507P)

TO: Steven Snyderman, Risk Review Manager Avivah Jakob, Team Leader Patricia Parrott, Branch Chief Risk Management and Implementation Branch 3

Pesticide Re-Evalua tion Division (7508P)

Attached is the Registration Review Problem Fo rmulation for the herbicides metolachlor (PC code 108801) and S-metolachlor (PC code 108800).

### 2 

# REGISTRATION REVIEW

PROBLEM FORMULATION

______________________________________________________________________________



# Metolachlor and S-Metolachlor

CAS Numbers: 51218-45-2 (metolachlor ) and 87392-12-9 (S-metolachlor)

US EPA PC Codes: 108801 (metolachl or) and 108800 (S-metolachlor)

Prepared by: Robin Sternberg, Ph.D., Wildlife Biologist Christopher M. Koper, M.S., Chemist

Environmental Risk Branch 1

Reviewed by: Edward Odenkirchen, Ph.D., Senior Advisor Stephen Wente, Ph.D., Biologist

Environmental Risk Branch 1 U.S. Environmental Protection Agency Office of Pesticide Programs

Environmental Fate and Effects Division

Environmental Risk Branch I 1200 Pennsylvania Ave., NW

Mail Code 7507P Washington, DC 20460

### 3 

## 1 Executive Summary

The Environmental Fate and Effects Division (E FED) has completed the preliminary problem formulation (attached) for the ecological risk, environmental fate, endangered species, and drinking water assessments to be conducted as pa rt of the Registration Review of metolachlor and S-metolachlor. For simplicity, metolachlor is used to represent the 1:1 mixture of (R)- and(S)-enantiomers of metolachlor in the document and S-metolachlor represents the more Senantiomer enriched registration. The problem form ulation describes the methods planned to be used during the completion of drinking water an d ecological risk assessm ents in support of Registration Review and provides an overview of the environmental fate, ecological effects, and potential risks associated with the use of meto lachlor/S-metolachlor as well as uncertainties unique to risk assessment of metolachlor/S-metolachlor. This document also identifies

additional studies that would be beneficial for conducting an ecological ri sk assessment. Major findings include the following data needs:

 OCSPP 835.4100: Aerobic Soil Metabolism: 2 additional soils (metolachlor or S-metolachlor, TGAI)

 OCSPP 835.4200: Anaerobic Soil Metabolism: 3 additional soils (metolachlor or S-metolachlor, TGAI)

 OCSPP 835.4300: Aerobic Aquatic Metabolism: 1 additional sediment system (metolachlor or S-metolachlor, TGAI)

 OCSPP 835.4400: Anaerobic Aquatic Metabolism: 1 additional sediment system (metolachlor or S-metolachlor, TGAI)

 OCSPP 850.7100: ECM/ILV: method and independe nt validation in so il and independent validation in water. (metolachlor or S-metolachlor, TGAI)

 OCSPP 850.2100: Avian acute oral toxicity te st, passerine species (metolachlor or Smetolachlor, TGAI)

 OCSPP 850.4100: Seedling emergence and seedling growth

– S-metolachlor (TEP): four species of dicots, one of which is soybean

– Degradate Metolachlor-ESA (TGAI): ryegrass, tomato, and carrot

– Degradate Metolachlor-OA (TGAI): onion

 OCSPP 850.4150: Vegetative vigor

– S-metolachlor (TEP): four species of dicots, one of which is soybean

 Non-guideline study: Chronic or al toxicity to adult honey bees (metolachlor or Smetolachlor, TGAI)

 Non-guideline study: Chronic oral toxicity to larval honey be es extended to include an acute endpoint (metolachlor or S-metolachlor, TGAI)

 Non-guideline study: Pollen and nectar residue studies (metolachlor or S-metolachlor, TGAI) – The need for these stud ies is contingent upon the resu lts of lower tier bee studies

 OCSPP 850.3040: Semi-field and field test ing for pollinators (metolachlor or Smetolachlor, TGAI) – The need for field tes ting is contingent upon the results of lower

tier bee studies

 Non-Guideline: Whole sediment: chronic invertebrates, freshwater and marine (metolachlor or S-metolachlor, TGAI)

### 4  Label clarifications: specifically includi ng an annual maximum application rate, the maximum number of applications allowed per year (and crop cycle, if applicable), minimum application interval, and a lb a.i./A application rate for the ornamental band

treatment use.

As previously stated in a 2002 EFED memo (USEPA, 2002), the ecological effects data are supportive of bridging toxicity prof iles of metolachlor a nd S-metolachlor. Therefore, similar to assessments in the past, the most sensitive endpoi nts from registrant-submitted guideline studies or open literature studies will be used for the Registration Review ecological risk assessment regardless of whether the endpoi nt is derived from a study co nducted with metolachlor or Smetolachlor.



## 2 Introduction

Metolachlor and S-metolachlor have separate registrations. Metolachlor (PC 108801), also known as racemic metolachlor, was first regi stered in 1976 and is a 1:1 mixture of ( R )- and ( S )-

enantiomers of metolachlor. S-metolachlor (PC 108800), conditio nally registered in 1997, is enantomerically enriched with the more active ( S )-enantiomer ( i.e. , 12% ( R ): 88% ( S )). Metolachlor and S-metolachlor are pre-plant inco rporated/pre-emergence/early post-plant broadspectrum herbicides in the chloroacetamide ch emical family used to control grasses and broadleaf weeds in non-agricultura l (S-metolachlor only) and/or ag ricultural (both) settings. Metolachlor and S-metolachlor act via inhibiting seedling shoot and meristematic growth.

EFED evaluated the most recent ecological risk assessments for me tolachlor in association with updated toxicity, exposure, and usage information to determine if sufficient data are available and if further updates are needed to support Regi stration Review. In addition, EFED considered the latest Agency science policies and risk assessment methodologies.



## 3 Use Characterization

Metolachlor and S-metolachlor are pre-plant in corporated/pre-emergence/ early post-plant broad spectrum herbicides in the chloroacetamide chemi cal family used to control seedling grasses, nutsedges, and certain annual broadleaf weeds such as nightshades, lambs quarter, and pigweeds in both agricultural and non-agricu ltural settings. It is registered for several major and minor food uses. Products containing metolachlor or s- metolachlor are applie d using aerial and ground equipment. The chemical profile produced by BEAD, compiled into Appendix A and Appendix

B , lists the use patterns of ma ximum exposures (based on pounds of active ingredient applied)

for the current uses of metolachlor and S-metolach lor. EFED will use application scenarios that result in maximum exposure scenarios for a given use for the risk assessment. There is some missing label information in some of the labels . Specifically, many of the national and special

local needs uses for metolachlor and s-metol achlor are missing maximum yearly application rates. Many of these labels only report a seasonal maximum a pplication; however, some of the crops may be grown multiple times per year. C onsequently, the label should be clarified to indicate a maximum yearly application rate and/or the maximum numb er of seasons (crop cycles) in one year for that crop. Many labels did not specify the number of applications that could be made. In some instances, the number of applications could be estimated based on the

### 5 yearly or seasonal maximum application rate. Exceptions to this were: metolachlor – corn, peanuts, safflower and soybean; s-metolachlor – al falfa, broccoli, corn, peanuts, pepper (special local needs only), pumpkin, safflower, sorghum and s unflower. In these in stances, there was not enough information on the label to estimate the number of applications that could be made. The minimum application interval was also missing for most uses. Finally, the ornamental band treatment application rate could not be converted into lb a.i./A, as needed for environmental modeling. See Appendices A and B for detailed in formation about application rates and where assumptions can be made. The absence of a ma ximum single application rate, an application interval or number, a maximum annual application rate (lbs a.i./year), an d/or application method on labels may result in conservative assumptions.



## 4 Conclusions from Previous Risk Assessments

4.1 Ecological Risk Assessments

EFED has conducted numerous ecological risk assessments on metolach lor and S-metolachlor that serve as a basis for this problem formulati on. A table summarizing previous assessments for

metolachlor/S-metolachlor can be found in Appendix C . Recent ecological risk assessments for metolachlor include a 1994 assessment supporting the Agency’s 1995 Re-registration Eligibility Decision (RED) (USEPA, D185152 and D172022) 1 

### , a 2006 litigation assessment for 26 evolutionarily significant units (ESUs) of lis ted salmonids in the Pacific Northwest, 2007 litigation assessments for the Barton Springs sa lamander and California red legged frog (CRLF), and a 2010 litigation assessment for the San Franci sco Bay (SFB) area species, delta smelt and California tiger salamander. R ecent ecological risk assessments for S-metolachlor include a 2010 litigation assessment for the SFB area species, delta smelt and California tiger salamander,

a 2010 assessment associated with the IR-4 proposed new use on sesame, melon, bushberry, caneberry, sorghum, leafy Brassica, turnip greens , carrot, cucumber, okra, dry bulb onions, and green onions (DP 370759), a 2011 assessment associat ed with an emergency exemption for use on lettuce in Michigan (DP 390436), and a 2012 asse ssment associated with the IR-4 proposed new use on cilantro and garden beet leaves (DP 392602). The litigation assessments can be

accessed at: http://epa.gov/espp/litstatus/effects/ (salmonids, Barton Springs salamander) or http://epa.gov/espp/litstatus/ effects/redleg-frog/index.html (CRLF, SFB area species).

The most recent, comprehensive assessment conduc ted for metolachlor and S-metolachlor is a

section 3 action for the use of S-metolachlor on cilantro and garden beet leaves (USEPA 2012, D392602), which was issued in 2012. The major ecolo gical conclusions presented in the section 3 ecological risk assessment were as follows:

Table 1. Summary of Risk Concerns Identified for S-Metolachlor 1 

### in Most Recent Section 3 Ecological Risk Assessment for Use on Cilantro and Garden Beet Leaves

Birds Mammals Terr.

Plants Terr.

Inverts Fish Bioaccumulation

Factor Aquatic

Inverts Aquatic

Plants Groundwater

Contamination Persistence De g radate s of Concer n

Yes a Yes a Yes No No No Yes a Yes Yes Yes b Yes

1 The assessment was conducted on S-metolachlor, but the conclusions would be similar for metolachlor.

1 http://www.epa.gov/oppsrrd1/REDs/0001.pdf

### 6 Yes =at least one LOC has been exceeded in previous assessments; " No " = LOCs have not been exceeded in previous assessments; NA = RQs have not b een calculated previously.

a Levels of Concern exceeded from chronic exposure. Risk to birds (surrogate for terrestrial-phase amphibians and reptiles) consuming short grass exclusively from use on garden beet leaves.

b Persistence is a function of environmental conditions as degradation is dependent on microbially-mediated and abiotic processes.



### Collectively, the historical a ssessments of metolachlor/S-metolachlor have identified the potential for risk to:

 mammals (listed and non- listed, chronic exposure),

 birds (listed and non-list ed, chronic exposure),

 terrestrial plants,

 freshwater fish (listed, acute exposure; listed and non-listed, chronic exposure),

 freshwater invertebrates (listed a nd non-listed, chronic exposure), and

 aquatic vascular and non-vascular plants.

4.2 Drinking Water Exposure Assessments

A drinking water exposure assessment was con ducted in 2010 for S-metolachlor and its degradates ethanesulfonic acid (ESA) and oxanili c acid (OA) in association with the IR-4 proposed new use on sesame, melon, bushberry, caneberry, sorghum, leafy Brassica, turnip greens, carrot, cucumber, okra, dry bulb onions, a nd green onions. Due to the extensive water monitoring data available for metolachlor/S-metolachlor, estimated drinking water concentrations (EDWCs) were a combination of modelling and monitoring data (USEPA. 2010. D368735).

4.3 Clean Water Act Programs

Metolachlor and S-metolachlor ar e not identified as a cause of impairment for any water bodies listed as impaired under secti on 303(d) of the Clean Water Act. No Total Maximum Daily Load (TMDL) criteria have been developed for metola chlor or S-metolachlor. Aquatic benchmarks

have been established for metolachlor and S-metolachlor and are available at http://www.epa.gov/oppefed1/ecoris k_ders/aquatic_life_benchmark.htm . Any data submitted or otherwise located as part of th e Registration Review process may be used to update aquatic life benchmarks, if applicable.



## 5 Environmental Fate and Transport

Metolachlor is a racemic mixtur e of R- and S-enantiomers (stereo isomers that are mirror images). Metolachlor is composed of approximately equal proportions of the R and S enantiomers, whereas S-metolachlor is an enrichment comprised almost solely of the S enantiomer (88% S-isomer). Enantiomers have the same chemical and physical properties except for the direction they rotate plane polarized light . The Agency has concluded that environmental

behavior of metolachlor and S-metolachlor is expected to be similar. Therefore, the environmental fate data were bridged from metolachlor to S-metolachlor (USEPA, 2002).

### 7 Environmental fate data indicate that parent metolachlor/S-metola chlor appear to be moderately persistent to persistent. Metolachlor/S-metol achlor degradation appear s to be dependent of microbially-mediated (aerobic soil metabolism t 1/2 

### = 13.9 to 67 days; anaer obic soil metabolism

t 1/2 

### =81 days) and abiotic processe s (photodegradation in water t 1/2 

### = 70 days under natural sunlight and photodegradation on soil t 1/2 

### = 8 days under natural sunlight).

Depending on the soil (i.e. organic matter content) , metolachlor/S-metolachlor has the potential to be mobile to moderately mobile with Koc values ranging from 21.6 to 369 mL/g oc and have been detected extensively in su rface water and groundwater. The Ag ency concluded that there is no difference in soil sorption affinity between metolachlor and S-metolachlor as there were similar Koc coefficients in the batch equilibr ium studies conducted on both active ingredients independently [mean Koc=135 (racemic) and 219 (S-enriched)] (USEPA 2002).

Field dissipation studies indicate that metolachlor/ S-metolachlor is persistent in surface soil with half-lives ranging from 3 to 292 days in the upper six inch soil laye r depending on geographic location. Metolachlor/S-metolachlor was reportedly de tected as deep as 36 to 48 inches in some

of the studies.

The Metolachlor Task Force (MTF) has conducte d a small scale prospective groundwater study (MRIDs 47017401-04) for metolachlor in order to co mply with the request of groundwater data for conditional registration of the technical me tolachlor. The residue sample collection was initiated in June 2003 continuing through 939 da ys after application. The objective was to determine the potential for the active ingred ient metolachlor and its degradates (CGA-37735, CGA-51202, CGA-67125, CGA- 41638, and CGA-354743) to reach groundwater when used in a vulnerable hydrogeologic setting. The study results show that metolachlor and two of its degradation products CGA-51202 and CGA-354743 can leach through the vadose zone into groundwater when applied in a vulnerable hydrogeologic setting. The detected peak concentrations of the degradation products CGA-51202 and CGA-354743 are higher than the detected peak

metalochlor concentrations.



### Metolachlor appears to have a low potential to bioaccumulate in fish with a reported whole body

bioconcentration factor of 69X and a whole body elimination of 93% after 14 days depuration.

The major organic degradates CGA-354743 (metolachlor-ESA; 12.4% formation; MRID 43928936) and CGA-51202 (metolachlor-OA; 28.1% formation; MRID 31309801A-B) are more persistent and mobile than their parent(s) a nd have been identified in both ground water and surface water. Two additional major degradates were identified in aerobic soil metabolism studies using Metolachlor and S-metolach lor, CGA-40172 (11.6% formation; MRID 45499606) and CGA-50720 (Formation 14.85%; MRID 3 1309801A-B). The most recent physical, chemical, environmental fate and transport proper ties of metolachlor and S-metolachlor are listed

in Table 5-1.

Table 5-1. Chemical Properties and Environmen tal Fate Parameters of Metolachlor and SMetolachlor

Parameter Value Source/MRID #

Common Name Metolachlor

S-Metolachlor Product
Chemistry

### 8 Parameter Value Source/MRID #

CAS Number 51218-45 -2 (Metolachlor)
87392-12-9 (S-Metolachlor)

Chemical Name 2-Chloro-N-(2-ethyl-6-methylphenyl)-N-(1-methoxy-2-
propanyl)acetamide (Metolachlor)

2-Chloro-N-(2-ethyl-6-methylphenyl)-N-[(2S)-1-methoxy2-propanyl]acetamide (S-Metolachlor)

Chemical Class/Category Chloroacetanilid e Herbicide

Empirical formula C 15 H 22 ClNO 2

Structure

Molecular Mass 283.79 g/mole

Water Solubility 530 mg/L at 20  C

Vapor pressure (25  C) 2.78 x 10 -5 mm Hg

Henry’s Law Constant 2.16 x 10 -8 atm m 3 /mol Calculated 1

Octanol/water partition
coefficient (K

ow ) 1122 (log Kow = 3.05) Product
Chemistry

Dissociation Constant (pKa) No dissociation within pH 2-12 Product
Chemistry

Hydrolysis at 25  C (t 1/2 ) pH 5 = stable
pH 7 = stable
pH 9 = stable 40430201

Aqueous Photolysis (t 1/2 )
(pH 7) 70 days 40430202

Soil Photolysis (t 1/2 ) 8 days (natural light)
37 days (artificial light) 40430203

43928935

Aerobic Soil Metabolism

25  C (t 1/2 ) 67 days (sandy loam)

50.3 days (sandy clay loam) S

14.9 days (sandy clay loam) S

13.9 days (sandy clay loam) S 41309801

45499606 S

45499606 S

45499606 S

Anaerobic Soil Metabolism

25  C (t 1/2 ) 81 days (sandy loam) 41309801

Aerobic Aquatic Metabolism

25  C (t 1/2 ) 47 days (sandy loam sediment) 41185701

Anaerobic Aquatic Metabolism 78 days (sandy loam sediment)

### 9 Parameter Value Source/MRID #

25  C (t 1/2 ) 41185701

Soil Partition Coefficient (K

oc )
(mL/g) 369 (clay)
188 (sand)
119 (sandy loam)

110 (silt loam)

66.7 (clay)
21.6 (sand)
110.4 (loam)
74.4 (sandy loam) 43928937 S

40494604

Terrestrial Field Dissipation
(t 1/2 ) 112.3 days (GA Bare Soil )
3.0 days (GA Grass )
20.8 days (GA Thatch )

128.1 days (IA Cropped Soil)

123.8 days (IA Bare Soil)

144.3 days (IA Cropped Soil)

117.1 days (IA Bare Soil)

120.0 days (IA Cropped Soil)
115 days (IA Bare Soil)

135 days (IA Cropped Soil)

152 days (IA Bare Soil)

132 days (CA Cropped Soil)

97 days (CA Bare Soil)

193 days (CA Cropped Soil)

292 days (CA Bare Soil) 45848001

41335701

41484203

41335702

41484204

41309802

41484201

41309803

41484202

41309804

41484205

41309805

41484206

Laboratory Volatility 0.05% volatilized/day (100% humidity) 40494606

Bioaccumulation in Fish
(BCF) 15X edible tissues; 70% depuration phase (14 days)
159X non-edible tissues; 96% depuration phase (14 days)
69X whole fish; 93% depuration phase (14 days) 41154201

Groundwater Monitoring Degradates CGA-51202 an d CGA-354743 can leach
through the vadose zone into groundwater and their
detected peak concentrations are higher than parent

metolachlor concentrations wh en applied in a vulnerable
hydrogeologic setting. 47017401

47017402

47017403

47017404

### 10 Parameter Value Source/MRID #

1 = Henry’s Law (atm-m 3 /mole) = (VAPR/760)/(SOL/MWT), where VAPR is vapor pressure in torr, MWT is
molecular weight in g/mol, and SOL is the solubility in water in mg/L.

S = denotes study using S-metolachlor.



### 5.1 Transformation Products

The major organic degradates of metolachlor/S-metolachlor in submitted environmental fate studies were identified as CGA-354743 (metolach lor ethane sulfonic acid or metolachlor-ESA), CGA-51202 (metolachlor oxanilic acid or me tolachlor-OA), CGA- 40172 and CGA-50720. Among these, metolachlor ESA and metolachlor OA are more persistent than their parents and have been identified in both ground water and su rface water. In additi on, a variety of minor degradates were observed in a variety of studies. Table 5-2 summarizes the transformation products of metolachlor/S-metolachlor and their maximum amounts formed.11Table 5-2. Metolachlor/S-Metolachlorand Its Environmental DegradatesCode Name/SynonymChemical NameChemical StructureStudy TypeMRIDMaximum Formation(% Applied)ParentMetolachlor(CGA-24705)CAS Name:(R)2-Chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamideCAS Number:051218-45-2Molecular Weight:283.80g/molChemical Formula:C15H22NO2ClSMILES:CCc1cccc(C)c1N(C(C)COC)C(=O)CClParent structure shown for referenceS-Metolachlor(CGA-77102)CAS Name:(S)-2-Chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamideCAS Number:087392-12-9Molecular Weight:283.80g/molChemical Formula:C15H22NO2ClSMILES:Cc1cccc(CC)c1N(C(=O)CCl)C(C)COCParent structure shown for referenceTransformation Products12Code Name/SynonymChemical NameChemical StructureStudy TypeMRIDMaximum Formation(% Applied)MetolachlorOxanilic Acid/Metolachlor-OA(CGA-51202)CAS Name:[(2-ethyl-6-methylphenyl) (2-methoxy-1-methylethyl) amino]oxo-acetic acidMolecular Weight:389.06g/molChemical Formula:C15H21NO4SMILES:COCC(N(c1c(C)cccc1CC)C(=O)C(=O)O)CAqueous Photolysis 404302023.54Aerobic Soil Metabolism 4549960611.3 (day 48)Aerobic Soil Metabolism 4392893610.3 (day 21, met)10.9 (day 21, S-met)Aerobic Soil Metabolism31309801A-B28.09 (day 90)Anaerobic Soil Metabolism31309801A-B23.33 (day 29)Terrestrial Field Dissipation 458480013.0% of applied Smetolachlor at 93 daysin 0-15 cm soil depth.Metolachlorethane sulfonicacid/MetolachlorESA(CGA-354743)CAS Name:2-((2-ethyl-6-methylphenyl)(2-methoxy-1-methylethyl)amino)-2-oxoethanesulfonic acidMolecular Weight:329 g/molChemical Formula:C15H23NO5SSMILES:O=S(=O)(O)CC(=O)N(c1c(cccc1CC)C)C(COC)C(chem spider)Aerobic Soil Metabolism 4549960611.6 ( day 33)Aerobic Soil Metabolism 4392893610.7 (day 60, met)12.4 (day 60, S-met)Terrestrial Field Dissipation 458480012.8% of applied Smetolachlor at 93 daysin 0-15 cm soil depth13Code Name/SynonymChemical NameChemical StructureStudy TypeMRIDMaximum Formation(% Applied)CGA-41507 CAS Name:N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamideMolecular Weight:249.36g/molChemical Formula:C15H23NO2Aerobic Aquatic Metabolism 411857013.34 (day 29)Anaerobic AquaticMetabolism411857014.85 (12 months)CGA-40172 CAS Name:Not reportedMolecular Weight:346.03g/molChemical Formula:C15H23NO3SMILES:c1c(c(c(cc1)C)N(C(=O)(CO))C(COC)C)CCAerobic Aquatic Metabolism 411857011.13Anaerobic AquaticMetabolism411857015.64 (12 months)Aerobic Soil MetabolismS4549960611.6 (day 19)11.3 (day 48)CGA-41638CAS Number:65513-61-3Molecular Weight:346.03g/molAqueous Photolysis 404302023.63Aerobic Soil Metabolism31309801A-B2.06day 90)14Code Name/SynonymChemical NameChemical StructureStudy TypeMRIDMaximum Formation(% Applied)Chemical Formula:C14H26ClNO2SMILES:Anaerobic Soil Metabolism31309801A-B8.30 (day 60)CGA-50720CAS Name:Not assignedMolecular Weight:346.03g/mol207.23 (Pubchem)Chemical Formula:C11H13NO3SMILES:CCc1cccc(c1NC(=O)C(=O)O)CAerobic Aquatic Metabolism 411857011.17Aqueous Photolysis 404302023.20Aerobic Soil Metabolism41309801A-B14.85 (day 272)Anaerobic Soil Metabolism41309801A-B7.34 (day 60)CGA-37913CAS Name: not reportedMolecular Weight: not reportedg/molChemical Formula: not reportedSMILES: not reportedAnaerobic AquaticMetabolism411857014.28 (6 months)CGA-37735CAS Name: not reportedMolecular Weight: not reportedg/molChemical Formula: not reportedAerobic Soil Metabolism31309801A-B1.27 (day 30)15Code Name/SynonymChemical NameChemical StructureStudy TypeMRIDMaximum Formation(% Applied)SMILES: not reportedAnaerobic Soil Metabolism31309801A-B1.25 (day 29)CGA-13656CAS Name: not reportedMolecular Weight: not reportedg/molChemical Formula: not reportedSMILES: not reportedAerobic Soil Metabolism31309801A-B1.02 (day 1)Anaerobic Soil Metabolism31309801A-B1.46 (day 29)CGA-46129CAS Name: not reportedMolecular Weight: not reportedg/molChemical Formula: not reportedSMILES: not reportedAqueous Photolysis 404302023.42CGA-46127 CAS Name:Aerobic Aquatic Metabolism 411857011.5416Code Name/SynonymChemical NameChemical StructureStudy TypeMRIDMaximum Formation(% Applied)N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)-2-(methylthio)acetamideMolecular Weight:295.44g/molChemical Formula:C16H25NO2SAnaerobic AquaticMetabolism411857014.69 (12 months)NOA-436611(STGA)sulfoxide of thioglycolic acidAerobic Soil Metabolism 454996069.4 (day 33)CGA-46576Aerobic Soil Metabolism 454996063.6 (day 7)CO2Carbon DioxideO=C=OAerobic Soil Metabolism 45499606 0.1 (48 days)Aerobic Soil Metabolism 4392893620.2OrganicVolatilesAerobic Soil Metabolism 4549960622.0 (8 days)Aerobic Soil Metabolism41309801A-B4.84 (day 366)17Code Name/SynonymChemical NameChemical StructureStudy TypeMRIDMaximum Formation(% Applied)UnextractableResiduesAerobic Soil Metabolism41309801A-B67.38 (day 366)Anaerobic Soil Metabolism41309801A-B37.94 (day 60)Note: Bold values denote major (> 10%) degradates.

### 18 

## 6 Receptors

6.1 Metolachlor and S-Metolachlor

As previously stated in a 2002 EFED memo (USEPA, 2002), the ecological effects data are supportive of bridging toxicity pr ofiles of metolachlo r and S-metolachlor. Although the studies were not conducted using identical test conditions and procedures, the to xicity of metolachlor and S-metolachlor are similar except for the risk to non-target te rrestrial plants ( Table 6-1 ). Specifically, the only difference in risk is associated with a slightly greater risk of S-metolachlor to non-target terrestrial plants. Therefore, simila r to assessments in the past, the most sensitive endpoints from registrant-submitted gui deline studies or open literature studies will be used for the Registration Review ecological risk assessment regardless of whether the endpoint is derived from a study conducted with metolachlor or S-meto lachlor. Summaries of the most sensitive endpoints used to characterize the toxicity of metolachlor/S-meto lachlor to non-target organisms are provided in Table 6-2 . Summaries of all submitted metolachlor and S-metolachlor toxicity

data can be found in Appendix D

.

For metolachlor/S-metolachlor, no da ta are available for the following:

 acute oral toxicity to a passerine species;

 chronic oral toxicity to adult honey bees;

 acute and chronic oral toxici ty to honey bee larvae; and

 toxicity to benthic invertebrates.

Metolachlor/S-metolachlor is classified as: up to moderately toxic to fish and aquatic invertebrates on an acute basis; practically non-toxic to birds on ac ute oral and sub-acute dietary bases; and practically non-t oxic to adult honey bees on acute contact and oral bases.

6.2 Degradates

Summaries of the endpoints used to characterize the toxicity of the major degradates of metolachlor/S-metolachlor, metalochlo r-OA (CGA-51202) and metolachlor-ESA (CGA354743), to non-target orga nisms are provided in Table 6-3 . Toxicity data are available for terrestrial plants, freshwater fish (acute), fr eshwater aquatic invertebrates (acute), aquatic vascular plants, and aqua tic nonvascular plants.

In general, the degradates are less toxic to non-t arget organisms than metolachlor/S-metolachlor. Specifically, metolachlor-OA and metolachlor-ESA are one, three, and two orders of magnitude less toxic to aquatic animals, aquatic plants , and terrestrial plants , respectively, than

metolachlor/S-metolachlor.19Table 6-1. Comparison of Toxicity Endpoints for Metolachlor and S-Metolachlor and Degradates Metolachlor-OA andMetolachlor-ESAaStudy typeSpeciesEndpointMetolachlor(CGA-77102)S-Metolachlor(CGA-24705)MetolachlorOA(CGA-51202)MetolachlorESA(CGA-354743)Avian acute oral Mallard duck LD50(mg/kg-bw) 4640 >2194NOAEL (mg/kg-bw) Not specified 2194Bobwhite quail LD50(mg/kg-bw)>2194NOAEL (mg/kg-bw)874Avian sub-acute dietary Mallard duck LC50(mg/kg-diet) >10,000 >4912NOAEC (mg/kg-diet) Not specified 1556Bobwhite quail LC50(mg/kg-diet) >10,000 >4912NOAEC (mg/kg-diet) Not specified 2762Avian reproduction Mallard duck NOAEC (mg/kg-diet) 800Bobwhite quail NOAEC (mg/kg-diet) 403 1000Mammalian acute oral Rat LD50(mg/kg-bw) 27803267Mammalian reproduction Rat NOAEC (mg/kg-diet) 300Acute oral with adult bees Honey bee LD50(μg/bee) >110 >200Acute contact with adult bees Honey bee LD50(μg/bee) >110 >85Terrestrial plant seedling emergence Monocot EC25(lb/A) 0.017 0.0048 >0.5 >0.5NOAEC/EC05(lb/A) 0.0031 0.0010 <0.5 <0.5Dicot EC25(lb/A) 0.09 0.0057 >0.5 >0.5NOAEC/EC05(lb/A) 0.012 0.0003 <0.5 <0.5Terrestrial plantvegetative vigorMonocot EC25(lb/A) 0.016 0.021 >0.5 >0.5NOAEC/EC05(lb/A) 0.0031 0.011 0.5 0.5Dicot EC25(lb/A) 0.030 0.27 >0.5 >0.5NOAEC/EC05(lb/A) 0.025 0.01 0.5 0.5Acute freshwater fish Rainbow trout LC50(mg/L) 3.80 11.9 >96.3 48NOAEC (mg/L) Not specified 2.5 96.3 36Bluegill sunfish LC50(mg/L) 10.3 3.2NOAEC (mg/L) 6.0 1.5Chronic freshwater fish Fathead minnow NOAEC (mg/L)0.030Acute estuarine/marine fish Sheepshead minnow LC50(mg/L) 7.9 16.8NOAEC (mg/L) 3.6 6.04Chronic estuarine/marine fish Sheepshead minnow NOAEC (mg/L) 1.0Acute freshwater aquatic invertebrate Water flea(CeriodaphniadubiaorDaphniaEC50(mg/L) 25.1(registrant)1.1(ECOTOX)26 (registrant) 15.4 >108NOAEC (mg/L) 5.6 (registrant) 4.8 (registrant) 5.2 10820Study typeSpeciesEndpointMetolachlor(CGA-77102)S-Metolachlor(CGA-24705)MetolachlorOA(CGA-51202)MetolachlorESA(CGA-354743)magna)Chronic freshwater aquatic invertebrateDaphnia magnaNOAEC (mg/L) 3.2 (registrant)0.001(ECOTOX)5.17(registrant)0.1(ECOTOX)Acute estuarine/marine mollusc Eastern oyster EC50(mg/L) 1.6NOAEC (mg/L) 0.71Acute estuarine/marine invertebrate Mysid shrimp LC50(mg/L) 4.95NOAEC (mg/L) 2.3Chronic estuarine/marine invertebrate Mysid shrimp NOAEC (mg/L)0.00013Aquatic vascular plantLemnaEC50(mg/L) 0.048 0.021 >95.4 43NOAEC (mg/L) 0.0084 0.0076 95.4 4Aquatic nonvascular plant Green alga EC50(mg/L) 0.010 0.008057.1>99.45NOAEC (mg/L) 0.0007 0.001529.399.45Freshwater diatom EC50(mg/L) 0.38 18NOAEC (mg/L) 0.0037 4.08Marine diatom EC50(mg/L) 0.061 0.11NOAEC (mg/L) 0.0017 0.021Cyanobacterium EC50(mg/L) 1.2 21NOAEC (mg/L) 0.063 9.6ashaded, empty cells indicate that there are no data availableTable 6-2. Summary of Most Sensitive Endpoints fromToxicity Studies with Metolachlor/S-MetolachlorStudy TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationAvian acute oral:single dose, 8-dayobservation (insteadof usual 14-dayobservation)Metolachlortechnical(NS)Mallard duck(Anas platyrhynchos)LD50(95% C.I.) = 4640 (3000-7200) mg/kg-bw (nom)NOAEC : Not specifiedPractically non-toxicMRID 00015547Supplemental(due to guidelinedeviations)Avian acute oral:single dose, 14-dayobservationS-Metolachlortechnical(87.4)Mallard duck(Anas platyrhynchos)LD50> 2194 mg a.i./kg-bw (m)NOAEC = 2194 mg a.i./kg-bw (m)(no sublethal effects or treatment-related mortality)Practically non-toxicMRID 43928906Acceptable21Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationAvian acute oral:single dose, 14-dayobservationS-Metolachlortechnical(87.4)Bobwhite quail(Colinus virginianus)LD50> 2194 mg a.i./kg-bw (m)NOAEC = 874 mg a.i./kg-bw (m)LOAEC = 1390 mg a.i./kg-bw (m)(no mortality; body weight losses at≥1390 mg/kg-bw)Practically non-toxicMRID 43928907AcceptableAvian acute oral Metolachlor Passerine species No data NAAvian sub-acutedietary: 5-dayexposure; 3-daypost-exposureobservationS-Metolachlortechnical(87.4)Mallard duck(Anas platyrhynchos)LC50> 4912 mg/kg-diet (m)NOAEC = 1556 mg a.i./kg-diet (m)LOAEC = 2762 mg a.i./kg-diet (m)(20% [2/10] mortality at 874 mg/kg-diet; NOAEC based onslight reduction in body weight gain at≥2762 mg/kg-diet duringthe first 5 days of the test)Practically non-toxicMRID 43928909AcceptableS-Metolachlortechnical(87.4)Bobwhite quail(Colinus virginianus)LC50> 4912 mg/kg-diet (m)NOAEC = 2762 mg a.i./kg-diet (m)LOAEC = 4912 mg a.i./kg-diet (m)(no mortality; NOAEC based on slight reduction in body weightgain at 4912 mg/kg-diet during the first 5 days of the test)Practically non-toxicMRID 43928908AcceptableAvian reproduction:~20 weeks (chronic)Metolachlortechnical(97.2)Bobwhite quail(Colinus virginianus)NOAEC = 403 mg a.i./kg-diet (mm)LOAEC = 1010 mg a.i./kg-diet (mm)(based on increase in cracked eggs)MRID 46508901AcceptableAvian reproduction:20 weeks (chronic)Metolachlortechnical(97.3)Mallard duck(Anas platyrhynchos)NOAEC = 800 mg a.i./kg-diet (nom)LOAEC > 800 mg a.i./kg-diet (nom)(no treatment-related effects)MRID 44015602AcceptableMammalian acuteoral, limit: singledose; 7-dayobservation (insteadof usual 14-dayobservation)Metolachlor(NS)Rat(Rattus norvegicus)LD50(95% C.I.) = 2780 (2180-3545) mg/kg-bw(20,30, 50, and 100% mortality at 1670, 2150, 2780, and 4640mg/kg-bw ; sublethal effects : dose-dependent increase insedation, dyspnea, exophthalmos, curved position, trismus,tonic-clonic muscle spasms, andruffled fur ; surviving animalsrecovered within 3 to 5 days)Practically non-toxicMRID 00015523Acceptable22Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationMammalian acuteoralS-MetolachlorRat(Rattus norvegicus)Combined sexes LD50= 3267 mg/kg-bwMale LD50= 2577 mg/kg-bwFemale LD50= 2672 mg/kg-bwPractically n0n-toxicMRID43928915Mammalian acuteinhalationMetolachlorRat(Rattus norvegicus)LC50> 1.75 mg/L MRID 00015535Mammalianreproduction(chronic)MetolachlorRat(Rattus norvegicus)NOAEC = 300 mg a.i./kg-diet(based on reduced pup weights in F1 and F2 litters)MRID 00080897AcceptableAcute contact withadult honey bees:single dose, 48-hourobservationMetolachlor(97)Adult honey bee(Apis mellifera)LD50> 110 μg a.i./bee (nom)NOAEL = 110 μg a.i./bee (nom)(no control mortality ; 0-5% mortality across 4 treatmentconcentrations)Practically non-toxicMRID 44718401AcceptableAcute oral with adulthoney bee, limit:single dose, 72-hourobservationS-Metolachlor(98.5)Adult honey bee(Apis mellifera)LD50> 85 μg a.i./bee (nom)NOAEL = 85 μg a.i./bee (nom)(3% control mortality ; 3-10% mortality across 9 treatmentlevels)Practically non-toxicMRID 44718402AcceptableAcute oral withhoney bee larvaeNA Larval honey bee No data NAChronic oral withhoney bee adultsNA Adult honey bee No data NAChronic oral withhoney bee larvaeNA Larval honey bee No data NATerrestrial plantseedling emergence:21 daysS-Metolachlortechnical(97.6)Most sensitivemonocot: RyegrassEC25= 0.0048 lb a.i./ANOAEC = 0.0010 lb a.i./A(based on phytotoxicity)MRID 43928932Supplemental(due to only testing6 species instead ofthe required 10)Most sensitive dicot:LettuceEC25(95% C.I.) = 0.0057 (0.0011-0.0308) lb a.i./ANOAEC = 0.0003 lb a.i./A(based on dry weight)Terrestrial plantvegetative vigor:21 daysMetolachlortechnical(97.3)Most sensitivemonocot: RyegrassEC25= 0.016 lb a.i./ANOAEC = 0.0031 lb a.i./A(based on dry weight)MRID 43487108Acceptable23Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationMost sensitive dicot:CucumberEC25(95% C.I.) = 0.030 (0.020-0.046) lb a.i./ANOAEC = 0.025 lb a.i./A(based on dry weight)Freshwater fishacute: 96 hours,staticS-Metolachlortechnical(Not reported)Bluegill sunfish(Lepomis macrochirus)LC50(95% C.I.) = 3.2 (2.8-4.6) mg a.i./L (im)Probit slope (95% C.I.) = 14.8 (2.1-27.5)NOAEC = 1.5 mg a.i./L (im)LOAEC = 2.59 mg a.i./L (im)(NOAEC based on no mortalityor sublethal effects at≤1.5mg/L; swimming on surface at≥3.29 mg/L)Moderately toxicMRID 43928910AcceptableFreshwater fishacute: 96 hoursMetolachlortechnical(NS)Rainbow trout(Salmo gairdneri)LC50(95% C.I.) = 3.80 (3.37-4.27) mg/L (nom)NOAEC: Not specified(no mortality at≤2.8 mg/L; mortality at≥4.1 mg/L)Moderately toxicMRID 00018722AcceptableFreshwater fish earlylife stage: 30+ days,flow-throughS-Metolachlortechnical(98.6)Fathead minnow(Pimephales promelas)NOAEC = 0.030 mg a.i./L (mm)LOAEC = 0.056 mg a.i./L (mm)(based on most sensitive endpoint of dry weight; length alsoaffected)MRID 44995903AcceptableEstuarine/marinefish acute: 96 hours,flow throughMetolachlortechnical(97)Sheepshead Minnow(Cyprinodonvariegatus)LC50(95% C.I.) = 7.9 (4.4-∞) mg/L (mm)NOAEC: Not specified(no mortality at≤4.4 mg/L; 70% mortality at 9.4 mg/L)Moderately toxicMRID 43044602Supplemental(due to guidelinedeviations)Estuarine/marinefish early life stage(chronic): 26 days,flow throughMetolachlortechnical(97)Sheepshead Minnow(Cyprinodonvariegatus)NOAEC = 1.0 mg/L (mm)LOAEC = 2.2 mg/L (mm)(NOAEC based on most sensitive endpoint of reduced length;survival and hatch also affected)MRID 43044602Supplemental(due to guidelinedeviations)Freshwaterinvertebrate acute:48 hours, staticMetolachlor(Not reported)Water flea(Ceriodaphnia dubia)EC50(95% C.I.) = 1.1 (0.9-1.4) mg/LModerately toxicE067777Quantitative(Fosteret al., 1998)Freshwaterinvertebrate lifecycle: 21 days, staticrenewalMetolachlor(Not reported)Water flea(Daphnia magna)NOAEC = 0.001 mg/L (nom)LOAEC = 0.01 mg/L (nom)(based on number of young per female)E083887Quantitative(Liuet al,2006)24Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationEstuarine/marineinvertebrate acute:96 hours, flowthroughMetolachlortechnical(97.3)Mysid shrimp(Mysidopsis bahia)EC50(95% C.I.) = 4.95 (4.21-5.94) mg a.i./L (mm)Probit slope (95% C.I.) = 6.1 (3.5-8.6)NOAEC = 2.3 mg a.i./L (mm)LOAEC = 4.0 mg a.i./L (mm)(NOAEC based on no mortality at≤2.3 mg/L; survivingdaphnids at 4.0 and 7.1 mg/L exhibited dark pigmentation andlethargy)Moderately toxicMRID 43487103AcceptableEstuarine/marinemollusc acute: 96hours, flow through,shell depositionMetolachlortechnical(97.3)Eastern oyster(Crassostreavirginica)EC50(95% C.I.) = 1.6 (1.4-1.9) mg a.i./L (mm)NOAEC = 0.71 mg a.i./L (mm)LOAEC = 1.1 mg a.i./L (mm)(sublethal effects: reduction in feeding and fecal andpseudofecal production wereobserved at all observationintervals at the highest treatment level, 4.5 mg/L)Moderately toxicMRID 42378901AcceptableEstuarine/marineinvertebrate lifecycle: 28 days, flowthrough (chronic)S-MetolachlortechnicalMysid shrimp(Mysidopsis bahia)NOAEC = 0.130 mg a.i./L (mm)LOAEC = 0.250 mg a.i./L (mm)(based on most sensitive endpoints of female length and dryweight; reproduction also affected)MRID 44995902AcceptableBenthic freshwaterinvertebrateMetolachlorFreshwater species No data NABenthicestuarine/marineinvertebrateMetolachlorEstuarine/marinespeciesNo data NAAquatic vascularplant: 14 days, staticS-Metolachlor(97.6)Duckweed(Lemna gibba)EC50(95% C.I.) = 0.021 (0.019-0.023) mg a.i./L (mm)NOAEC = 0.0076 mg a.i./L (mm)LOAEC = 0.018 mg a.i./L (mm)(based on most sensitive endpoint of frond number, biomass alsoaffected; sublethal effects:less root formation at≥0.0076 mg/L,compared to the control; chlorosis at≥0.018 mg/L)MRID 43487105AcceptableAquatic nonvascular plant:120 hours, staticS-Metolachlor(97.6)Green alga(Selenastrumcapricornutum)EC50(95% C.I.) = 0.0080 (0.0026-0.025) mg a.i./L (mm)NOAEC = 0.0015 mg a.i./L (mm)LOAEC = 0.0030 mg a.i./L (mm)(based on cell density; sublethal effects: bloated cells at≥0.0015mg/L; cell fragments at≥0.0030 mg/L)MRID 43928929Acceptable25Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationAquatic nonvascular plant:120 hours, staticMetolachlortechnical(97.3)Marine diatom(Skeletonemacostatum)EC50(95% C.I.) = 0.061 (0.049-0.076) mg a.i./L (mm)NOAEC = 0.0017 mg a.i./L (mm)LOAEC = 0.0048 mg a.i./L (mm)(based on cell density; sublethal effects: cell fragments andbloated cells at≥0.15 mg/L; thin cell walls at≥0.56 mg/L)MRID 43487106AcceptableAquatic nonvascular plant:120 hours, staticMetolachlortechnical(97.3)Freshwater diatom(Navicula pelliculosa)EC50(95% C.I.) = 0.38 (0.27-0.56) mg a.i./L (mm)NOAEC = 0.0037 mg a.i./L (mm)LOAEC = 0.013 mg a.i./L (mm)(based on cell density; sublethal effects: bloated cells and cellfragments at≥0.13 mg/L)MRID 43541302AcceptableAquatic nonvascular plant:120 hours, staticMetolachlortechnical(97.3)Cyanobacterium(Anabaena flos-aquae)EC50(95% C.I.) = 1.2 (0.9-1.6) mg a.i./L (mm)NOAEC = 0.063 mg a.i./L (mm)LOAEC = 0.19 mg a.i./L (mm)(based on cell density; cell fragments at≥0.72 mg/L; bloatedcells at 6.8 mg/L)MRID 43487104AcceptableAbbreviations: C.I. = confidence interval; form. = formulation; im = initial measured; mm = mean measured; nom = nominal; NA =not applicable; NS = notspecified; TEP = typicalend-use product; TWA = time-weighted average26Table 6-3. Summary of Most Sensitive Endpoints from Toxicity Studies with Degradates ofMetolachlor: Metolachlor-ESA(CGA-354743) and Metalochlor-OA (CGA-51202)Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationTerrestrialinvertebrate: 14 daysMetolachlor-ESA(92)Earthworm(Eisenia foetida)LC50> 920 mg a.i./kg-dry soil (nom)NOAEC = 920 mg a.i./kg-dry soil (nom)MRID 44931721Supplemental(not a guidelinestudy)Terrestrial plantseedling emergence:Tier I, 21 daysMetolachlor-ESA(92)Most sensitivemonocot: RyegrassEC25< 0.5 lb a.i./ANOAEC < 0.5 lb a.i./A(based on dry weight)MRID 44931718Supplemental(due to noNOAEC)Most sensitive dicot:Tomato, carrotEC25> 0.5 lb a.i./ANOAEC < 0.5 lb a.i./A(NOAEC based on emergence and dry weight for tomato andcarrot, respectively)Terrestrial plantvegetative vigor:Tier I, 21 daysMetolachlor-ESA(92)Most sensitivemonocot: NoneEC25> 0.5 lb a.i./ANOAEC = 0.5 lb a.i./AMRID 44931718AcceptableMost sensitive dicot:NoneEC25> 0.5 lb a.i./ANOAEC = 0.5 lb a.i./ATerrestrial plantseedling emergence:Tier I, 21 daysMetolachlor-OA(99.9)Most sensitivemonocot: OnionEC25> 0.5 lb a.i./ANOAEC < 0.5 lb a.i./A(NOAEC based on emergence)MRID 44929513Supplemental(due to no monocotNOAEC)Most sensitive dicot:NoneEC25> 0.5 lb a.i./ANOAEC = 0.5 lb a.i./A(NOAEC based on dry weight and length, respectively)Terrestrial plantvegetative vigor:Tier I, 21 daysMetolachlor-OA(99.9)Most sensitivemonocot: NoneEC25> 0.5 lb a.i./ANOAEC = 0.5 lb a.i./AMRID 44929513AcceptableMost sensitive dicot:NoneEC25> 0.5 lb a.i./ANOAEC = 0.5 lb a.i./AFreshwater fishacute: 96 hours,staticMetolachlor-ESA(95)Rainbow trout(Oncorhynchusmykiss)LC50(95% C.I.) = 48 (36-64) mg a.i./L (mm)NOAEC = 36 mg a.i./L (mm)LOAEC = 64 mg a.i./L (mm)(NOAEC based on no mortalityand sublethal effects at≤36mg/L; sublethal effects: erratic swimming, loss of equilibriumand pigmentation changes at 64 and 112 mg/L)Slightly toxicMRID 44931702Supplemental(due to guidelinedeviations)27Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationFreshwater fishacute: 96 hours,staticMetolachlor-OA(Not reported)Rainbow trout(Oncorhynchusmykiss)LC50> 96.3 mg/L (mm)NOAEC = 96.3 mg/L (mm)Practically non-toxicMRID 44929501Supplemental(due to notreporting the testmaterial purity andguidelinedeviations)Freshwater fishacute: 96 hours,staticMetolachlor-OA(Not reported)Crucian carp(Cyprinus carpio)LC50> 93.1 mg a.i./L (mm)NOAEC = 931. Mg a.i./L (mm)Practically nontoxicMRID 44929502Supplemental(due to notreporting the testmaterial purity andguidelinedeviations)Freshwaterinvertebrate: 48hours, staticMetolachlor-ESA(95)Water flea(Daphnia magna)LC50> 108 mg a.i./L (mm)NOAEC = 108 mg a.i./L (mm)(no treatment-related mortality or sublethal effects)Practically non-toxicMRID 44931703AcceptableFreshwaterinvertebrate acute:48 hours, staticMetolachlor-OA(Not reported)Water flea(Daphnia magna)EC50(95% C.I.) = 15.4 (13.0-18.4) mg a.i./L (mm)Probit slop (95% C.I.) = 6.1 (3.8-8.4)NOAEC = 5.2 mg a.i./L (mm)LOAEC = 9.05 mg a.i./L (mm)(NOAEC based no mortality at 5.2 mg/L)Slightly toxicMRID 44929503Supplemental(due to notreporting testmaterial purity)Aquatic vascularplant: 14 days, staticMetolachlor-ESA(99)Duckweed(Lemna gibba)7-day EC50(95% C.I.) = 43 (30-61) mg a.i./L (im)7-day EC05= 4.0 mg a.i./L (im)7-day NOAEC < 6.1 mg a.i./L (im)7-day LOAEC = 6.1 mg a.i./L (im)(based on frond number; sublethal effects: small and shriveled at≥24 mg/L; chlorosis of half of fronds at 98 mg/L)Note: Since the NOAEC is non-definitive (i.e., NOAEC < lowesttest concentration), the EC05will be used for assessing risk tolisted species.MRID 44931720AcceptableAquatic vascularplant: 14 days, staticMetolachlor-OA(>99.9)Duckweed(Lemna gibba)EC50> 95.4 mg a.i./L (im)NOAEC = 95.4 mg a.i./L (im)MRID 44929514Acceptable28Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationAquatic nonvascular plant:72 hours, staticMetolachlor-ESA(99.9)Green alga(Selenastrumcapricornutum)EC50> 99.45 mg a.i./L (mm)NOAEC = 99.45 mg a.i./L (mm)(based on cell density)MRID44931719Supplemental(due to guidelinedeviations)Aquatic nonvascular plant:72 hours, staticMetolachlor-OA(Not reported)Green alga(Scenedesmussubspicatus)EC50(95% C.I.) = 57.1 (29.3-∞) mg/L (im)NOAEC = 29.3 mg/L (im)LOAEC = 92.2 mg/L (im)(based on cell density)MRID 44929515Supplemental(due to purity oftest material notbeing reported andonly 72-hourexposure)Abbreviations: C.I. = confidence interval; form. = formulation; im = initial measured; mm = mean measured; nom = nominal; NA =not applicable; NS = notspecified; TEP = typicalend-use product; TWA = time-weighted average

### 29 6.3 Ecological Incidents

A preliminary review on June 27, 2014 of the Ec ological Incident Information System (EIIS, version 2.1.1), which is maintained by the Agency ’s Office of Pesticide Programs, and the Avian Monitoring Information System (AIMS), whic h is maintained by the American Bird Conservancy, indicates a total of 269 reported ecological incidents associated with the use of metolachlor and 206 reported ecologi cal incidents associated with th e use of S-metolachlor. This total excludes incidents classified as ‘unlikely’ or ‘unrelated’ and only includes those incidents with certainty categories of ‘ possible’, ‘probable’, and ‘hig hly probable’ (for EIIS) and ‘possible’, ‘probable’, ‘l ikely’, ‘highly likely’ and ‘certain’ (f or AIMS). Incidents classified as ‘unlikely’ the result of or ‘unrelated’ to metolachlor or S-meto lachlor will not be included in this Problem Formulation or the ecological risk a ssessment conducted for Registration Review.

All of the metolachlor incidents, excluding those classified as ‘unlik ely’ or ‘unrelated’, occurred

between 1984 and 2014. Thirteen of the metolachlo r incidents reported in the EIIS database involved aquatic animals, 2 invol ved terrestrial animals, and 254 involved plants. The certainty categories regarding the likelihood that the use of metolachlor ca used the 269 incidents were probable (99 incidents), possible (167 incidents), and highly proba ble (3 incidents). One hundred and sixty-seven of the incidents we re considered registered uses at the time of the incident, 17 involved misuses, and the legality of use wa s undetermined in 85 incidents. The reported

incidents for metolachlor involved 265 uses that are currently regi stered [agriculture area, corn, nut, peanut, potato, soybean, turf, and wheat], and 4 in which the use site was not specified.

Incidents are reported separately for S-metolach lor, but the number and type of reports are similar. There were a total of 206 reported in cidents for S-metolachlo r. Twenty-nine involved terrestrial animals and 177 involved plants. Of the 29 incidents that involve d terrestrial animals, only 1 was a bird incident also reported in AIMS (EIIS: 1015105). The certainty categories regarding the likelihood th at the use of S-metolachlor caused the 206 incidents were probable (74 incidents) and possible (132 in cidents). One hundred and forty- two of the incidents were considered registered uses at the time of the incident, 7 involved misuses, and the legality of use

was undetermined in 57 incidents. Based on the da ta, it appears that most of the reports are undesired effects treatment site, when applied in accordance with a registered use. The most commonly reported crops damaged we re corn, cotton, and soybean.

In addition to the incidents reco rded in EIIS and AIMS, additiona l incidents have been reported to the Agency in aggregated incident reports. Pesticide registrants re port certain types of incidents to the Agency as a ggregate counts of incidents occu rring per product per quarter. Ecological incidents reported in aggregate reports include those cat egorized as ‘minor fish and wildlife’ (W-B), ‘minor plant’ (P -B), and ‘other non-target’ (ONT ) incidents. ‘Oth er non-target’ incidents include reports of adve rse effects to insects and other terrestrial invertebrates. For metolachlor, registrants have reported 5 minor fish and wildlife incidents, 44 minor plant incidents, and 0 other non-target incidents. For S-metolachlor, re gistrants have reported 4 minor fish and wildlife incidents, 672 minor plant inci dents, and 0 other non-target incidents. Unless additional information on these aggregated incident s becomes available, they will be assumed to be representative of registered uses of metol achlor and S-metolachlor in the risk assessment.

### 30 In the risk assessment, the incidents will be fu rther evaluated to determine if the reported incidents represent current patt erns of use for metolachlor a nd S-metolachlor. Examples of additional considerations are mitigation (e.g., re duced application rates), product cancellations, and changes in use patterns that have occurred since the date of the re ported incident(s).



## 7 Exposure Pathways of Concern

The environmental fate properties and use patter ns of metolachlor/S-metolachlor indicate that direct spray, spray drift, leaching to ground wa ter, atmospheric deposition, and runoff represent potential transport mechanisms of metolachlor/S-metolachlor to aquatic and terrestrial organisms. Drinking water and inhalation expo sure pathways were sc reened using the SIP (Screening Imbibition Program) and STIR (Scr eening Tool for Inhalation Risk) screening methods, respectively. Inhalation was found to be an exposure pathway of low concern (no LOC exceedances are expected; Appendix E ). Results of SIP ( Appendix E ) indicate that drinking water could be an exposure pathway of concer n for birds (acute and chronic exposure) and mammals (chronic exposure). SIP and STIR are described in detail at: http://www.epa.gov/oppefed1/ models/terrestrial/index.htm

.



## 8 Analysis Plan

8.1 Stressors of Concern

8.1.1 Ecological Risk Assessment

Although degradates metolachlo r-ESA and metolachlor-OA are less toxic than parent metolachlor/S-metolachlor, they are more persistent and are formed to a significant extent in fate

studies and are often detected in monitoring studies. Therefore, the stressors of concern for aquatic and terrestrial organisms are metolachlo r/S-metolachlor and degradates metolachlor-ESA

and metolachlor-OA. Similar to assessments in the past, risk to non-target organisms will be assessed separately for metolachlor/S-metolach lor, metolachlor-ESA, and metolachlor-OA.

8.1.2 Drinking Water Exposure Assessment

The drinking water assessments conducted to suppor t the Registration Review human health risk assessments of metolachlor/S-metolachlor will incorporate modeled estimates of parent compounds metolachlor/S-metolachlor and degrad ate residues of concern in surface and ground

waters. The metolachlor/S-metolachlor residues of concern may be reev aluated pending receipt

and review of additional environmental fate and toxicity data for metolachlor/S-metolachlor and its degradates. Following the recommendation of the Residues of Concern Knowledgebase Subcommittee (ROCKS), parent metolach lor, CGA-51202 (metolachlor-OA), CGA-40172, and CGA-50720 will be assessed together in the dr inking water assessment using a total toxic residues (TTR) approach and will follow th e latest guidance and methodology (USEPA, 2014c, D424250).

8.2 Measures of Exposure

### 31 EFED will use standard available models to evaluate potential exposures to aquatic and terrestrial organisms as described at http://www.epa.gov/pesticides/science/models_db.htm

.

8.2.1 Available Monitoring Data

The Agency is aware of monitoring conducted by fe deral and state agencies and this information

will be considered in the assessment to the ex tent that data on metolachlor are available.

8.3 Measures of Effect

Toxicity data presented in Section 6 of this problem formulation w ill be used to calculate risk quotients. Any additional information submitted by th e registrant or found in the open literature prior to conducting the risk assessment will also be considered. The open literature studies are identified using EPA’s ECOTOXicology database (ECOTOX) 2 

### , which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife. The evaluation of both sources of data can also provi de insight into the direct and indirect effects of pesticides on biotic communities from loss of species that are sensitiv e to the chemicals and from changes in structure and functional ch aracteristics of the affected communities.



## 9 Endangered Species Assessments

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), the Agency will evaluate risks to federally listed th reatened and/or endangere d (listed) species from registered uses of pesticides in Registration Re view. The process for eval uating potential risks to listed species is further described at http://www.epa.gov/oppfead1/enda nger/litstatus/riskasses.htm

.



## 10 Endocrine Disruptors Screening Program

Metolachlor was included in the first group of 67 chemicals issued an or der to conduct Tier 1 EDSP testing. For additional info rmation the EDSP program, visit http://www.epa.gov/endo/

.



## 11 Preliminary Identification of Data Gaps

11.1 Environmental Fate

Table 11-1 identifies environmental fate studies by MRID that offer data for each guideline requirement, as well as study classi fications and whether or not furt her data are needed in order to support risk assessment.

2 http://cfpub.epa.gov/ecotox/

### 32 Table 11-1. Environmental Fate Data for Metolachlor/S-Metolachlor

OCSPP

Guideline Data Requirement Submitted

Studies
(MRID) Study

Classification Data Gap? Comments

835.2120 Hydrolysis 4043 0201 Acceptable No --
835.2240 Aqueous Photolysis 40430202 Acceptable No -- 835.2410 Soil Photolysis 43928935 Supplemental No --

835.4100 Aerobic Soil

Metabolism 41309801A-B Acceptable

Yes (Partially Fulfilled) The aerobic soil metabolism study was conducted with two soils. Data are required under

40 CFR Part 158. OCSPP guidance recommends that these studies be performed

with four soils. Two

additional soils are needed to fulfill the data requirement. 45499606 Supplemental
43928936 Supplemental

835.4200 Anaerobic Soil

Metabolism 41309801A-B Acceptable Yes (Partially Fulfilled) The anaerobic soil metabolis m study was conducted with only one soil. Data are required under 40 CFR Part 158. OCSPP guidance

recommends that these studies be performed with four soils.

Three additional soils are

needed to fulfill the data requirement.

835.4300 Aerobic Aquatic

Metabolism 41185701 Acceptable Yes (Partially Fulfilled) The aerobic aquatic metabolism study was

conducted with only one sediment –water system. Data are required under 40 CFR Part 158. OCSPP guidance

recommends that these studies be performed with two sediment-water systems. .

One additional sedimentwater system is needed to fulfill the data requirement.

835.4400 Anaerobic Aquatic

Metabolism 41185701 Acceptable Yes (Partially Fulfilled) The anaerobic aquatic metabolism study was

conducted with only one sediment –water system. Data are required under 40 CFR Part 158. OCSPP guidance

recommends that these studies be performed with two sediment-water systems. .

One additional sedimentwater system is needed to fulfill the data requirement.

### 33 OCSPP

Guideline Data Requirement Submitted

Studies
(MRID) Study

Classification Data Gap? Comments

835.1230

835.1240 Adsorption/ desorptio n and leaching 43928937 Acceptable* No --

40494602

40494603

40494604

40494605 Acceptable No --

835.1410 Volatility – laboratory 40494606 Acceptable No --

835.6100 Terrestrial Field Dissipation (TFD) 45848001 Supplemental* No --

41335701

41484203 (amendment) Supplemental No

--

41335702

41484204 (amendment) Supplemental No

--

41309802

41484201 (amendment) Supplemental No

--

41309803

41484202 (amendment) Supplemental No

--

41309804

41484205 (amendment) Supplemental No

--

41309805

41484206 (amendment) Supplemental No

--

835-7100 Groundwater Monitoring 47017401

47017402

47017403

47017404 Acceptable No --

850.7100 Environmental chemistry method (ECM/ILV) in soil -- -- Yes ECM/ILV in soil for

metolachlor/S-metolachlor is outstanding

Environmental chemistry method (ECM) in water 45499611 Supplemental* No --

45499612 Supplemental** No --

(ILV) in Water -- -- Yes ILV in water for

metolachlor/S-metolachlor is outstanding

850.1730 Fish Bioconcentrati on 41154201 Acceptable No --
* Study using S-metolachlor (CGA 77102). ** Study using metolachlor.



### 11.2 Ecological Effects

Table 11-2 identifies ecological effects studies by MR ID that offer data for each guideline requirement, as well as study classi fications and whether or not furt her data are needed in order to support risk assessment. Rationale for the ad ditional data requested is presented below the

tables.34Table 11-2. Ecological Effects Data for Metolachlor,S-Metolachlor, Metolachlor-OA, and Metolachlor-ESAOCSPPGuidelineDataRequirementChemicalSubmittedStudy(MRID)ClassificationAre data neededto conduct therisk assessment?Justification and Assumptions EPA Will Make in theAbsence of DataAvian Testing850.2100 Avian oraltoxicityMetolachlor 0001554700062465(waterfowl)SupplementalAcceptableNo Acute oral toxicity datafor a passerine species arerequired under the new 40 CFR Part 158. A study hasnot been submitted for this data requirement for eithermetolachlor or S-metolachlor.A guideline-compliant passerine acute oral toxicity test isneeded. The sublethal effect of body weight loss wasobserved in a study with bobwhite quail and Smetolachlor. Passerine birds may utilize metabolicpathways that are different from larger birds andtherefore be more sensitive to metolachlor. Furthermore,passerines exhibit behavioral responses to pesticidedosing that are potential indicators of reduced fitness inthe field (e.g., regurgitation of contaminated diet) evenwhen direct biochemically-mediated lethal toxicity is notapparent.In the absence of these data, passerine toxicity data forsurrogate pesticides – starting with data for closelyrelated pesticides (e.g., chloroacetamides) andproceeding to data for less related pesticides – may beused to characterize the acutetoxicity of metolachlor topasserine species.S-Metolachlor 43928906(waterfowl)Acceptable No43928907(upland game)AcceptableMetolachlorS-MetolachlorNo data(passerinespecies)NA Yes850.2200 Avian dietarytoxicityMetolachlor 44015602(waterfowl)AcceptableNo --46508901(upland game)AcceptableS-Metolachlor 43928909(waterfowl)AcceptableNo --43928908(upland game)Acceptable35OCSPPGuidelineDataRequirementChemicalSubmittedStudy(MRID)ClassificationAre data neededto conduct therisk assessment?Justification and Assumptions EPA Will Make in theAbsence of Data850.2300 AvianreproductionMetolachlor 46070102(upland game)Acceptable No --46070101(waterfowl)AcceptableS-metolachlor 44995901(upland game)Acceptable No Avian data for the reproductive toxicity of metolachlor towaterfowl will be bridged to S-metolachlor.(waterfowl) No dataInsect Pollinator Testing850.3020 Honey beeacute contacttoxicityMetolachlor 44718401 Acceptable No --S-Metolachlor 44718402 Acceptable No --SpecialStudy(OECD213)Honey beeadult acute oraltoxicityMetolachlor 44718401 Acceptable No --S-Metolachlor 44718402 Acceptable No --SpecialStudy(OECD237)Honey beelarvae acuteand chronicoral toxicityMetolachlorS-MetolachlorNo data NA YesGuidance for assessing pesticide risks to bees (USEPA,2014a) describes a screening-level (Tier 1) riskassessment process that includes acute contact and acuteand chronic oral toxicity tests with adult bees and acuteand chronic oral toxicity tests with larval bees. Chronicoral toxicity data for adult bees and acute and chronicoral toxicity data for beelarvae are not available formetolachlor or S-metolachlor.In the absence of these data,honey bee oral toxicity datafor surrogate pesticides – starting with data for closelyrelated pesticides (e.g., chloroacetamides) andproceeding to data for less related pesticides – may beused to characterize the oraltoxicity of metolachlor/Smetolachlor to honey bees.Per the guidance (USEPA, 2014), Tier 2 (feeding/semifield/pollen and nectar residue) and Tier 3 (full field)SpecialStudyHoney beeadult chronicoral toxicityMetolachlorS-MetolachlorNo data NA YesSpecialStudyPollinatorpollen andnectar residuestudiesMetolachlorS-MetolachlorNo data NA Need for datacontingent uponresults of Tier 1bee studies850.3040 Semi-field andfield testingfor pollinatorsMetolachlorS-MetolachlorNo data NA Need for datacontingent uponresults of Tier 1bee studies36OCSPPGuidelineDataRequirementChemicalSubmittedStudy(MRID)ClassificationAre data neededto conduct therisk assessment?Justification and Assumptions EPA Will Make in theAbsence of Datastudies may be needed, contingent upon the results of theTier 1 studies.Aquatic Organisms Testing850.1010Freshwaterinvertebrateacute toxicityMetolachlor 00015546 Acceptable No --S-Metolachlor 43928912 Acceptable No --Metolachlor-ESA 44931703 Acceptable No --Metolachlor-OA 44929503 Supplemental No Although the submitted study withD. magna is classifiedasSupplementaldue to not reporting test materialpurity, it is sufficient for quantitative use in theecological risk assessment.850.1025850.1035850.1045850.1055Saltwaterinvertebrateacute toxicityMetolachlor43487103(shrimp)Acceptable No --42378901(mollusc)AcceptableS-Metolachlor No data(shrimp)NA No Mysid and Eastern oyster acute toxicity data formetolachlor will be bridged to S-metolachlor.No data(mollusc)NA850.1075 Freshwaterfish acutetoxicityMetolachlor 0001553400018723(warm water)Acceptable/Supplemental(depending onspecies)AcceptableNo --00018722(cold water)AcceptableS-Metolachlor 43928910(warm water)Acceptable No --43928911(cold water)AcceptableMetolachlor-ESA 44931702 Supplemental No Although the submitted study with rainbow trout isclassified asSupplementaldue to guideline deviations, itis sufficient for quantitative use in the ecological riskassessment.Metolachlor-OA 4492950144929502SupplementalSupplementalNo Although the submitted studies with rainbow trout andcrucian carp are classified asSupplementaldue to not37OCSPPGuidelineDataRequirementChemicalSubmittedStudy(MRID)ClassificationAre data neededto conduct therisk assessment?Justification and Assumptions EPA Will Make in theAbsence of Datareporting the test material purity and guidelinedeviations, they are sufficient for quantitative use in theecological risk assessment.850.1075 Saltwater fishacute toxicityMetolachlor 4348710143044602AcceptableSupplementalNo --S-Metolachlor 46829506 Acceptable No --850.1300 Freshwaterinvertebratelife cycleMetolachlor 4632210143802601AcceptableSupplementalNo --S-Metolachlor 46829507 Acceptable No --850.1350 Saltwaterinvertebrateslife cycleMetolachlor No data NA No Mysid chronictoxicity data for S-metolachlor will bebridged to metolachlor.S-Metolachlor 44995902 Acceptable No --850.1400 Freshwaterfishearly life stageMetolachlor No data NA No Freshwater fishchronic toxicity data for S-metolachlorwill be bridged to metolachlor.S-Metolachlor 44995903 Acceptable No --850.1400 Saltwater fishearly life stageMetolachlor 43044602 Supplemental No Although the submitted study with sheepshead minnowis classified asSupplementaldue to guidelinedeviations, it is sufficient for quantitative use in theecological risk assessment.S-Metolachlor No data NA No Estuarine/marine fish chronic toxicity data formetolachlor will be bridged to S-metolachlor.NonGuidelineWholesediment:chronicinvertebrates,freshwaterand marineMetolachlorS-MetolachlorNo data NA YesChronic sediment invertebrate toxicity data are requiredunder 40 CFR Part 158 if:i.the estimated environmental concentration (EEC)in sediment is > 0.1 of the acute LC50/EC50values;ii.the half-life of the pesticide in sediment if > 10days in either the aerobic soil or aquaticmetabolism studies and if any of the followingexist:A.The soil partition coefficient (Kd) is≥50B.The log Kow is≥3.C.The Koc is≥1,000.The half-life of metolachlor/S-metolachlor in aerobic soilmetabolism and aerobic aquatic metabolism studies are38OCSPPGuidelineDataRequirementChemicalSubmittedStudy(MRID)ClassificationAre data neededto conduct therisk assessment?Justification and Assumptions EPA Will Make in theAbsence of Data49 and 141 days, respectively; and the log Kow ofmetolachlor/S-metolachlor 3.04.Modeling via the Surface Water ConcentrationCalculator (SWCC, v. 1.106)aindicates peak and 21-daypore water EECs of up to 41.9 and 41.8 μg/L,respectively. Although the peak pore waterconcentration is approximately 0.04 of the LC50of 1100μg/L forD. magna(E067777), the 21-day pore waterEEC is 41 * NOAEC of 1 μg/L forD. magna(E083887).According to toxicity testing and ecological riskassessment guidance for benthic invertebrates USEPA,2014b), if the 21-day pore water EEC≥1.0 * chronicwater column NOAEC, the need for chronic sedimenttoxicity testing is indicated.Therefore, chronic sediment tests with the midgeChironomus dilutus, freshwater amphipodHyalellaazteca, and/or estuarine/marine amphipodLeptocheirusplumulosusare needed. A tiered approach using toxicitydata from sub-chronic (10-day) sediment toxicity testswith the three species may be used to determine whichspecies should undergo chronic toxicity testing.In the absence of these data, sediment-dwellinginvertebrate chronic toxicity data for surrogate pesticides– starting with data for closely related pesticides (e.g.,chloroacetamides) and proceedingto data for less relatedpesticides – may be used to characterize the chronictoxicity of propargite to sediment-dwelling invertebrates.Nontarget area phytotoxicity testing850.4100 Seedlingemergenceand seedlinggrowthMetolachlor 43487107 Acceptable No --S-Metolachlor 43928932 Supplemental YesThe submitted study was classified asSupplementaldueto only testing 6 species instead of the required 10species. Testing with an additional four species ofdicots, one of which is soybean, is necessary.39OCSPPGuidelineDataRequirementChemicalSubmittedStudy(MRID)ClassificationAre data neededto conduct therisk assessment?Justification and Assumptions EPA Will Make in theAbsence of DataMetolachlorESA44931718 Supplemental YesThe submitted study was classified asSupplementaldueto not establishing NOAECsfor ryegrass, tomato, andcarrot. A study that defines a NOAEC (i.e., aconcentration that is not statistically different from thenegative control for all assessed endpoints) is needed.Metolachlor-OA 44929513 Supplemental YesThe submitted study was classified asSupplementaldueto not establishing a NOAEC for onion. A study thatdefines a NOAEC (i.e., a concentration that is notstatistically different from the negative control for allassessed endpoints) is needed.850.4150 VegetativevigorMetolachlor 43487108 Acceptable No --S-Metolachlor 43928933 Supplemental YesThe submitted study was classified asSupplementaldueto only testing 6 species instead of the required 10species. Testing with an additional four species ofdicots, one of which is soybean, is necessary.Metolachlor-ESA 44931718Acceptable No --Metolachlor-OA 44929513Acceptable No --850.4400 Aquatic planttoxicity testusingLemnaspp.Metolachlor 43487105 Acceptable No --S-Metolachlor 43487105 Acceptable No --Metolachlor-ESA 44931720 Acceptable No --Metolachlor-OA 44929514Acceptable No --850.4500 Algal toxicity Metolachlor 43541301(green alga)Acceptable No --43541302(freshwaterdiatom)Acceptable43487106(marinediatom)AcceptableS-Metolachlor 43928929(green alga)Acceptable No --40OCSPPGuidelineDataRequirementChemicalSubmittedStudy(MRID)ClassificationAre data neededto conduct therisk assessment?Justification and Assumptions EPA Will Make in theAbsence of Data46829509(freshwaterdiatom)Acceptable43928930(marinediatom)AcceptableMetolachlor-ESA Supplemental(green alga)Supplemental No Although the submitted study with a green alga isclassified asSupplementaldue to guideline deviations, itis sufficient for quantitative use in the ecological riskassessment.Metolachlor-OA 44929515(green alga)Supplemental No Although the submitted study with a green alga isclassified asSupplementaldue to the exposure length(72 hours instead of 96 hours) and the purity of testmaterial not being reported, it is sufficient forquantitative use in the ecological risk assessment.850.4550 CyanobacteriatoxicityMetolachlor 43487104 Acceptable No --S-Metolachlor46829510 Acceptable No --Abbreviations: NA = not applicableaCA Lettuce STD; 1 application @ 1.3 lb a.i./A

### 41 Study Title: Adult honey bee chronic oral toxicity Rationale for Requiring the Data

Terrestrial invertebrate chroni c toxicity data are required for metolachlor/S-metolachlor to quantitatively assess the potential effects on this group of organi sms. Bees can be exposed through multiple pathways including contact with sprays and through ingestion of residues in food/water ( e.g ., pollen/nectar and water used to maintain colony temperature). Worker bees foraging on flowers for pollen and nectar can be repeatedly exposed to residues in pollen and nectar either through direct contamination of these matrices by foliar sprays or through translocation of residues via systemic transport of s-metolachlor/metolachlor. Residues can in turn be brought back to bee colonies where in-hive bees including young adult and developing brood ( i.e ., eggs, larvae and pupae) may be e xposed. Honey bees are a surrogate

for all terrestrial invertebrates.

This is a non-guideline study; an OECD protocol is under development. A protocol should be submitted to the Agency for review before commencing the study and should include provisions for measuring the concentration of meto lachlor/S-metolachlor in the actual diet of the honey bee. Practical Utility of the Data

How will the data be used? The 10-day toxicity study with young adult bees provides no-observed adverse effect level (NOAEL) and lowest-observed adverse effect le vel (LOAEL) for assessing chronic effects. Data obtained from this study will be used inestimating chronic risk from metolachlor/Smetolachlor to individual adult bees, which will be used as a surrogate for all terrestrial

invertebrates. The data will reduce uncertainties associated with the re gistration review risk

assessment for terrestrial invertebrates and w ill improve EPA’s understanding of the potential

effects of s-metolachlor/metolach lor on terrestrial species. If honey bee chronic adult data are not submitted, risks to terrestri al invertebrates from chroni c exposure to metolachlor/Smetolachlor will be assumed.

How could the data impact the Agency’s future decision-making? If future endangered species risk assessments are performed without th ese data, the Agency

would have to assume that s-metolachlor/meto lachlor "may affect" endangered terrestrial invertebrates directly (and e ndangered species from other taxa indirectly), and use of metolachlor/S-metolachlor might need to be restricted in areas where endangered species could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Enda ngered Species Act and could result in use restrictions for s-metolachlor/metolachlor which are unnecessarily severe.

### 42 Study Title: Larval honey bee acute and chronic oral toxicity Rationale for Requiring the Data

Terrestrial invertebrate chronic toxi city data are required for metolachlor/S-metolachlor to quantitatively assess the potential effects on this group of organisms. Developing bee brood ( i.e ., larvae and pupae) can be exposed to metolachlor/S-meto lachlor through residues brought back to the colony by worker bees foraging in areas where the pesticide has been applied. While larvae are typically fed royal or brood jelly during their early stages of devel opment, worker bee (females) and drone (males) larvae are also fed pollen/honey (bee bread) direct ly by in-hive nurse bees. Honey bees are a surrogate for all terrestrial

invertebrates.

This is a non-guideline study; a 21 -day larval toxicity study is unde r development by OECD and provides both acute and chronic toxicity data on developing bee brood. Alternativ ely, a separate acute (single dose) larval toxicity study following OECD Guideline 237 as well as the 21-day repeat dose chronic toxicity study can be submitted to address both acute and chronic larval endpoints. A protocol for the 21-day larval toxicity test should be submitted to the Agency for review before commencing the study and should include provisions for measuring the concentration of s-metolachlor/meto lachlor in the actual diet of the honeybee.

Draft guidance for the 21-day larval toxicity study is available at: http://www.oecd.org/env/ehs/testing/Draf t_GD_honeybees_rep_exp_for_2nd_CR_25_November_2013.pdf Practical Utility of the Data

How will the data be used? Acute (LD 50 

### ) and chronic (NOAEL/LOAEL) toxicity data on developing bee brood will be used to determine the effects on survival and development (adult bee emergence) from repeat exposures to

metolachlor/S-metolachlor. Data obtained from this study will be used in estim ating risk to individual brood bees, which will be used as a surrogate for a ll terrestrial invertebrate s. The data will reduce

uncertainties associated with the re gistration review risk assessment fo r terrestrial invertebrates and will improve EPA’s understanding of the potential effects of metolachlo r/S-metolachlor on terrestrial species. If honey bee larval data ar e not submitted, risks to larval terres trial invertebrates from acute and chronic exposure to s-metolachlor/metolachlor will be assumed.

How could the data impact the Agency’s future decision-making? If future endangered species risk assessments are perf ormed without these data, th e Agency would have to assume that metolachlor/S-metolachlor "may affect " endangered terrestrial i nvertebrates directly (and endangered species from other taxa indirectly), and use of metolachlor/S-metolachlor might need to be restricted in areas where endangere d species could be exposed. The l ack of these data will limit the flexibility the Agency and registrants have in comi ng into compliance with the Endangered Species Act

and could result in use restrictions for s-metol achlor/metolachlor which are unnecessarily severe.

### 43 Study Title: Residue analysis of nectar and pollen in flowering crops Rationale for Requiring the Data Measured residues in pollen and ne ctar can serve as a means through wh ich screening-leve l risk quotients may be refined. Initially, risk estimates are based on e xposure values generated usi ng conservative models or default values. However, risk estima tes can be refined using measured resi due values in pollen and/or nectar collected by bees. Such data may be available through modifications to existing gu ideline studies identified for residue chemistry, including the magnitude of residue crop trial (OCSPP 860.1500[2]) and through field rotational crop trials (OC SPP 860.1900[3]). Table 2 depicts selected test requirements from the 40CFR Part158 Subpart O (Residue Chemistry §158.1410).

Table 2. Recommendations for Residue Data Requirements.

Number Study Type Use Pattern

Test

substance Test

Note

No. Terrestrial

Food or

Feed Aquatic

Food Greenhouse

Food Indoor

Food Residential

Outdoor

Magnitude of residue

8 60.1500 Crop field

trials R R R CR CR TEP

860.1900 Field

rotational

crops CR CR NR NR NT TEP

Alternatively, data on residues in po llen and nectar may be available through the ecological effect studies where pesticide is applied under semi - and full-field conditions. To s upport residue analysis in pollen and nectar, the registrant must provide evidence that suitable environmental chemistry methods (ECM) have been used to quantify residues.

Practical Utility of the Data To assess risk to non-target listed and non-listed terrestr ial invertebrate species. These data would allow the Agency to refine the screening level risk assessment for beneficial terrestri al invertebrates. Exposure data is an integral part of determining the potential for risk to beneficial terrestrial invertebrates through direct exposure from their food sources.

The data EPA intends to call in are necessary to info rm the determination required under FIFRA or the ESA as to whether continued registration of a pesticide is likely to result in unr easonable adverse effects or is not likely to jeopardize threatened or endangered species or it s critical habitat. The lack of these data will limit the flexibility that the Agency and registrants have in coming into compliance with ESA and could result in use restrictions that are unnecessarily severe. In addition, the lack of thes e data may result in an uncertain assumed risk and potential mitigation of pyraclostrobin formulations under FIFRA.

### 44 Study Title: Chronic Freshwater Sediment Testing Flow-through: ( Hyallela azteca ) ( Chironomus dilutus or C. tentans ) (Chironomus riparius ) (ORD Study Method EPA 600/R099-064)

Study Title: Chronic Estuarine/Marine Sediment Testing Flow-through: ( Leptocheirus plumulosus ) (ORD Study Method EPA 600/R-099-020)
Rationale for Requiring the Data
Based on physiochemical properties, the metolachlo r/s-metolachlor may sorb to organic materials in sediment and may be toxic to aquatic invertebrates that dwell in and ingest sediment. The use pattern, chemical properties, esti mated exposure, and toxicity prof ile of metolachlor/s-metolachlor indicate need for chronic (life cycle) sediment t oxicity tests to fully eval uate potential risks to benthic invertebrates. The 40 CFR part 158.630 requires a chronic freshwater sediment study

when the estimated environmental concentrati on (EEC) in sediment is > 0.1 of the actual

LC50/EC50 values and the half-life of the pesticide in the sediment is > 10 days and any of the following conditions exist: a. Kd > 50, b. the log Kow > 3, or c. the Koc > 1000. Metolachlor/smetolachlor meets these criteria. Multiple freshwater species ( Chironomus dilutus or C. tentans ; Hyalella azteca; Chironomus riparius ) and/or a saltwater species ( Leptocheirus plumulosus ) are needed to account for differential sensitivity and e xposure potential of benthic invertebrates to the pesticide active ingredient.
Practical Utility of the Data

How will the data be used? Data from sediment toxicity studies will be used to estimate potential risks to benthic organisms associated with the use of the pesticide active ingredient. The data will be used to reduce

uncertainties associated with the current risk assessment for benthic invertebrates.

How could the data impact the Agency’s future decision-making?

The data EPA intends to call in will inform the determination required under FIFRA or the ESA as to whether continued registration of a pesticide is likely to resu lt in unreasonable adverse effect non-target species or is not likel y to jeopardize listed or enda ngered species or its critical habitat. The lack of these data will limit the flexibility that the Agency and registrants have in coming in to compliance with ESA and could result in significant use restri ctions. In addition, the lack of these data may result in assumed risk a nd potential mitigation of metolachlor/s-metolachlor

formulations under FIFRA.



## 12 References

USEPA. 1995. Reregistration E ligibility Decision (RED). Data Package Barcode: 185152, 172022 Metolachlor. April 1995.

USEPA. 2002. Review of Documents Related to the Equivalency of Racemic Metolachlor (Metolachlor) and S-Metolachlor for Environmenta l Fate and Ecotoxicit y. Environmental Fate and Effects Division, Office of Pe sticide Programs. February 28, 2002.

### 45 USEPA, 2010. Drinking Water Assessment for S-Metolachlor and its Degradates Ethanesulfonic Acid (ESA) and Oxanilic Acid (OA) for Various Crop Uses. (DP 368735) April 22, 2010

USEPA, 2010 S-metolachlor Ecological Risk Assessment to Support the IR4 Registration for Numerous New Uses (DP 370759) June 23, 2010.

USEPA, 2011. FIFRA Section 18 Emergency Ex emption for the Use of S-Metolachlor on

Lettuce to Control Grass and Broadleaf Weed s Post Crop Emergence. (DP 390436) June 22,

2011.

USEPA, 2012. Ecological Risk Assessment for the Proposed New Uses of S-metolachlor on Cilantro and Garden Beet Leaves. (DP 392602) January 4, 2012

USEPA. 2014a. Guidance for Assessing Pesticide Ri sks to Bees. Environmental Fate and Effects Division. Office of Pesticide Programs. June 23, 2014.

USEPA. 2014b. Toxicity Testing and Ecologica l Risk Assessment Guidance for Benthic

Invertebrates. Environmen tal Fate and Effects Division. Office of Pesticide Programs. April 10,

2014.

USEPA. 2014c. Metolachlor and s-metolachlor: recommended environmental degradates to include in drinking water assessment. Health E ffects Division. Office of Pesticide Programs. (DP 424250) December 3, 2014.

E067777. Foster, S., Thomas, M., and K. Wolfga ng. 1998. Laboratory-derived acute toxicity of selected pesticides to Ceriodaphnia dubia . Australasian Journal of Ecotoxicology. 4: 53-59.

E083887. Liu, H., Ye, W., Zhan, X., and W. Li u. 2006. A Comparative Study of Rac- and SMetolachlor Toxicity to Daphnia magna . Ecotoxicology and Environm ental Safety. 63: 451-455.



## 13 Bibliography

Environmental Fate Studies (Metolachlor)

15662 Burkhard, N. (1974) CGA-24705: Hydrol ysis of CGA-24705 under Labo- ratory

Conditions. Method no. SPR 2/74 da ted Feb 27, 1974. (Unpublished study received Sep 26, 1974 under 5G1553; prep ared by Ciba-Geigy, Ltd., submitted by Ciba-Geigy Corp., Greens boro, N.C.; CDL:094222-H)

40430201 Spare, W. (1987) Determination of the H ydrolysis Rate Constants of Metolachlor: Agrisearch Project No. 1263. Unpublished st udy prepared by Agrisearch Inc. 41

p.

### 46 16300 Aziz, S.A.; Kahrs, R.A. (1974) Photolysis of CGA-24705 in Aqueous Solution

under Natural and Artificial Sun light Conditions: Report No. GAAC-74041.(Unpublished study received Sep 26, 1974 under 5F1606; submitted by CibaGeigy Corp., Greensboro, N.C.; CDL:094385-D)

16302 Aziz, S.A.; Kahrs, R.A. (1975) Photolysis of CGA-24705 in Aqueous Solution-- Additional Information: Report No. GAA C-75021. (Un- published study received on unknown date under 5F1606; submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:094385-M)

40430202 Spare, W. (1987) Determination of the So lution Photolysis Rate Con- stants and Photodegradation Products of Metolachlo r Under Natur- al and Artificial Light: Laboratory Study No. 1261. Unpublished study pr epared by Agrisearch Inc. 63 p.

40519301 Spare, W.; Capps, T. (1988) Determinat ion of the Solution Photolysis Rate Constants and Photodegradation Pro ducts of CGA-154281 Under Natural and Artificial Light: Proj. No. 1275. Unpublished study prepared by Agrisearch Inc. 101 p.

41210801 Spare, W.; Capps, T. (1988) Supplement To: Determination of the Solution Photolysis Rate Constants and Photod egradation Products of CGA-154281 Under Natural and Artificial Light: Project ID: MRID NO. 40519301. Unpublished study prepared by Agrisearch Inc. 13 p.

16301 Aziz, S.A. (1974) Photolysis of CGA- 24705 on Soil Slides under Nat- ural and Artificial Sunlight Conditions: Re port No. GAAC-74102. (Unpublished study received on unknown date under 5F1606; sub- mitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:094385-J)

40430203 Spare, W. (1987) Soil Photolysis of Metolachlor under Natural and Artificial Light: Laboratory Study No. 1262. Unpublis hed study prepared by Agrisearch Inc. 77 p.

43928935 Merritt, A. (1995) Photodegradation of (carbon 14)-Metolachlor and (carbon 14)-

CGA-77102 on Soil Under Artificial Sun light: Lab Project Number: ABR-95128: 53-95. Unpublished study prepared by Ciba Crop Protection. 151 p.

16296 Kaiser, F.E. (1974) Soil Degradatio n Study of Gba-Geigy ?sic| 14C- CGA-24705. (Unpublished study received Mar 27, 1975 unde r 5F1606; prepared by Analytical BioChemistry Laboratories, Inc., su bmitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:094376-N)

153668 Bouchard, D.; Lavy, T.; Marx, D. (1982) Fa te of metribuzin, meto- lachlor, and

fluometuron in soil. Weed Science 30:629-632.

41309801 Spare, W. (1989) Soil Metabolism of Metolachlor under Aerobic, Aerobic/Anaerobic, and Sterile Co nditions: Lab Project Number: 1258. Unpublished study prepared by Agrisearch Inc. in association with Ciba-Geigy Corp. 130 p.

### 47 41309802 Spare, W. (1989) Soil Metabolis m of Metalochlor under Aerobic, Aerobic/Anaerobic, and Sterile Co nditions: Lab Project Number: 1258. Unpublished study prepared by Agrisearch, Inc. 130 p.

43928936 Clark, A. (1995) Comparative Aerobic Soil Metabolism of Phenyl-(carbon 14)- CGA-77102 and Phenyl-(carbon 14)-Metol achlor: Lab Project Number: ABR95102: 338-94: 12217. Unpublished study prepar ed by Ciba Crop Protection and Agrisearch, Inc. 314 p.

44043401 Clark, A. (1995) Comparative Aerobic Soil Metabolism of Phenyl-(carbon 14)- CGA-77102 and Phenyl-(carbon 14)-Metol achlor: Report Amendments 1,2,3: Lab Project Number: ABR-95102: 338-94. Unpub lished study prepared by Ciba-Geigy Corp. 9 p.

44083203 Krueger, J.; Smith, K.; Butz, R. (1990) Comparative Aerobic Soil Degradation of SAN 582H, Alachlor, and Metolachlor: Lab Project Number: 414105-9: DP300038: 414105. Unpublished study prepared by Sandoz Agro, Ltd. 19 p.

15656 Dupre, G.D. (1974) Abbreviated Anaer obic Metabolism of 14C-CGA- 24705 in Silt Loam Soil under Greenhouse Conditions: Report No. 73019-3. (Unpublished study received Sep 26, 1974 under 5G1553; prepared by Bio/dynamics, Inc., submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:094222-B)

41309801 Spare, W. (1989) Soil Metabolism of Metolachlor under Aerobic, Aerobic/Anaerobic, and Sterile Co nditions: Lab Project Number: 1258. Unpublished study prepared by Agrisearch Inc. in association with Ciba-Geigy Corp. 130 p.

41309802 Spare, W. (1989) Soil Metabolis m of Metalochlor under Aerobic, Aerobic/Anaerobic, and Sterile Co nditions: Lab Project Number: 1258. Unpublished study prepared by Agrisearch, Inc. 130 p.

41185701 Spare, W. (1989) Aerobic and Anaerobic Aquatic Metabolism of Meta- lachlor: Final Report: Study No. 1259. Unpublished st udy pre- pared by Agrisearch Inc. 140 p.

15657 Dupre, G.D. (1974) Leaching Char acteristics of 14C-CGA-24705 and Its Degradation Products Following Aging in Sandy Loam Soil un- der Greenhouse Conditions: Report No. 73021-6. (Unpublished study received Sep 26, 1974 under 5G1553; prepared by Bio/ dynamics, Inc., submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:094222-C)

15658 Dupre, G.D. (1974) Runo ff Characteristics of 14C- CGA-24705 Applied to Sandy

Loam Soil under Greenhouse Conditi ons: Report No. 73022-1. (Unpublished study received Sep 26, 1974 under 5G1553; prepared by Bio/dynamics, Inc., submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:094222-D)

15659 Houseworth, L.D. (19??) Report on Pa rent Leaching Studies for CGA- 24705: Report No. 1. (Unpublished study receive d Sep 26, 1974 under 5G1553; prepared

### 48 by Univ. of Missouri, Dept. of Plan t Pathology, submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:094222-E)

31327 Black, D.K. (1978) Adsorption-Desorp tion Study Using Antor Herbi- cide. (Unpublished study received May 3, 1979 under 43142-1; submitted by Boots Hercules Agrochemicals Co., Wi lmington, Del.; CDL:098274-G)

31328 Harvey, R.G.; Jordan, G.L. (1978) Co mparative Study of the Biologi- cal and Physical Properties of Acetanilide Herbicid es in Soil. (Unpublished study received May 3, 1979 under 43142-1; prepared by Un iv. of Wisconsin, submitted by Boots Hercules Agrochemicals Co., Wi lmington, Del.; CDL:098274-H)

31329 Jordan, G.L.; Harvey, R.G. (1978) Environmental Factors and Soil Relationships Influencing the Activity of Acetanilide Herbi- cides. Doctoral Thesis, Univ. of Wisconsin, Dept. of Agronomy. (pp. 22- 58 only; unpublished study received May 3, 1979 under 43142-1; submitted by Boots Hercules Agrochemicals Co., Wilming- ton, Del.; CDL:098274-I)

32172 Herman, M.M.; Nixon, W.B.; Ball, J.; et al. (1980) ?Soil Dissapa- tion of Herbicides|: Report No. ABR-80017. (Unpublished study including AG-A No. 5409 I-V received Apr 30, 1980 under 100-597; prepared in cooperation with Uniroyal Inc., submitted by Ciba- Geigy Corp., Greensboro, N.C.; CDL:242551- A)

78291 Burkhard, N. (1978) Adsorption and De sorption of Metolachlor (Dual^(R)I) in Various Soil Types: Project Report 45/ 78. (Un- published st udy received Jul 23, 1981 under 100-587; prepared by Ciba-G eigy, Ltd., Switzerland, submitted by Ciba-Geigy Corp., Greens boro, N.C.; CDL:245627-D)

78301 Guth, J.A. (1975) CGA-24705 Leaching Model Study with the Herbicide CGA24705 in Four Standard Soils: Nr. SPR 3/75. (Unpublished study received Jul 23, 1981 under 100-587; prepared by Ciba- Geigy, Ltd., Switzerland, submitted by Ciba-Geigy Corp., Greens- boro, N.C.; CDL:245628-E)

118040 Burkhard, N.; Guth, J. (1981) Rate of volatilisation of pesticides from soil surfaces: Comparison of calculated results wi th those determined in a laboratory model system. Pestic. Sci. 12(1): 37-44. (Also In unpublished submission received Nov 5, 1982 under 4581-351; submitted by Agchem Div., Pennwalt Corp., Philadelphia, PA; CDL:248818-X)

153668 Bouchard, D.; Lavy, T.; Marx, D. (1982) Fa te of metribuzin, meto- lachlor, and

fluometuron in soil. Weed Science 30:629-632.

40494602 Spare, W. (1987) Leaching Characteristics of Parent Metolachlor: Laboratory Study No. 1234. Unpubllshed study prepar ed by Agrisearch, Inc. 77 p.

40494603 Spare, W. (1987) Leaching Characteristics of Aged Metolachlor: Laboratory Study No. 1233. Unpublished study prepar ed by Agrisearch, Inc. 53 p.

### 49 40494604 Spare, W. (1987) Determination of Adsorption/Desorption Constants of Metolachlor: Agrisearch Project N o. 1235. Unpublished study prepared by Agrisearch, Inc. 79 p.

40494605 Spare, W. (1988) Determinations of Adsorption/Desorption Constants of CGA51202: Agrisearch Project No. 1266. Unpub lished study prepared by Agrisearch, Inc. 66 p.

40629103 Spare, W. (1987) A Supplemental to the Determination of Adsorption Desorption Constants of ?carbon 14|-CGA-154281. U npublished study prepared by CibaGeigy Corp. 41 p.

43928937 Spare, W.C. ADSORPT ION/DESORPTION OF 14c-c ~~-771B0Y2 THE BATCH

EOUILIBRIUM METHOD ON REPRESEN TATIVE AGRICULTURAL SOILS. Sponsored and Submitted by Ciba-Geigy Protection, Ciba-Geigy Corporation, Greensboro, NC under Ciba-Geigy Study N o. 71-95 and Agrisearch Project No. 12218; Study completed on 11 July 1995; Received by EPA 26 January 1996;

MRID 43928937.

43928938 Spare, W.C. LEACHING CHARACTERIS TICS OF AGED 1 4 CGA 77102 in Four SOILTYPES. Sponsored and Su bmitted by Ciba-Geigy Protection, CibaGeigyCorporation, Greensboro, NC unde r Study No. 72-95; Performed by A grisearch Incorporated, Frederic k, MD under Agrisearch Project No. 18216; Study completed on 22 December 1995; Received by EPA 26 January 1996; MRID 43928938

44931722 Spare, W. (1997) Adsorption/Desorp tion of (carbon-14-CGA-354743) By the Batch Equilibrium Method on Representa tive Agricultural So ils: Lab Project Number: 92-97: 12240. Unpublished study prep ared by Agrisearch, Inc. 252 p.

40494606 Spare, W. (1987) The Volatilization of Metolachlor from Soil (A Laboratory Study): Agrisearch Project No. 1260. Unpub lished study prepared by Agrisearch, Inc. 60 p.

15610 Ballantine, L.G.; Herman, M.M. (1978) Dual^(R)I plus Bladex^(R)I Tank Mix Soil Dissipation Studies: Report No. A BR-78071. Summa- ry of studies 235360- C, 235360-D and 235360-G through 235360-J. (Unpublished study received Oct 20, 1978 under 100-583; submit- ted by Ci ba-Geigy Corp., Greensboro, N.C.; CDL:235360-A)

16303 Sumner, D.D.; Cassidy, J. E. (1975) The Degradati on of CGA-24705 in a Field Soil: Report No. GAAC-75022. (Unpublished study re- ceived on unknown date under 5F1606; submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:094385- N)

23515 Ballantine, L.G.; Herman, M.M.; Coan, R.M.; et al. (1979) Bi- cep^(R)I plus Roundup^(R)I or Paraquat and Dual^( R)I/Prin- cep^(R)I plus Roundup or Paraquat Tank Mix Soil Dissipati on Studies: Report No. ABR-79101.

### 50 (Unpublished study received Dec 10, 1979 under 100-583; prepared in cooperation with Chevron Chemical C o. and others, submitted by Ciba-Geigy Corp., Greens- boro, N.C.; CDL:241649-A)

27018 Ballantine, L.G.; Herman, M.M. (1 979) Bicep^(R)I pl us Roundup^(R)I or Paraquat and Dual^(R)I/Princep^(R)I pl us Roundup or Paraquat Tank Mix Soil Dissipation Studies: Report No. ABR- 79101. Sum- mary of studies 241649-B through 241649-Q. (Unpublished study received Dec 10, 1979 under 100-583; submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:241649-A)

64174 Herman, M.M.; Nixon, W.B. (1980) Dual^( R)I plus Premerge^(R)I Tank Mix Soil Dissipation Studies: Report No. ABR- 80021. (Unpub- lished study received Mar 31, 1981 under 100-597; submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:099991-A)

Metolachlor Plus Propazine Tank Mix Soil Dissinatioc ( r e p o r t #RBR-78037) Vol. 8 of 8, EPA P i l e No. 100-ANU. L. G. Ballantine and M. M. Herman, April 27, 1978.

64178 Herman, M.M.; Nixon, W.B. (1980) Dual ^(R)I plus Eptam^(R)I Tank Mix Soil Dissipation Studies: Report No. A BR-80022. (Unpublished study received Mar 31, 1981 under 100-597; submitted by Ciba- Geigy Corp., Greensboro, N.C.; CDL:099990-A)

134319 Herman, M.; Newby, L. (1978) Dual pl us Dyanap Tank Mix: Soil Dissi- pation Studies: ?Summary|: Report No. A BR-78069. (Unpublished study received Oct 11, 1979 under 100-583; submitted by Ciba - Geigy Corp., Greensboro, NC; CDL:241132-A)

41309803 Merricks, D. (1989) Metolachlor Field Dissipation Study in Iowa--Site A: Lab Project Number: 1265/A. Unpublished study pr epared by Agrisearch Inc. 324 p.

41309804 Merricks, D. (1989) Metolachlor Field Dissipation Study in California--Site C: Lab Project Number: 1264/C. Unpublished st udy prepared by Agrisearch, Inc. 334

p.

41309805 Merricks, D. (1989) Metolachlor Field Dissipation Study in California--Site C: Lab Project Number: 1265/C. Unpublished st udy prepared by Agrisearch, Inc. 334

p.

41335701 Merricks, D. (1989) Metolachlor Field Dissipation Study in Iowa--Site B: Final Report: Lab Project Nos. 1264-B; 1264. Unpublished study prepared by Agrisearch Inc. 300 p.

41335702 Merricks, D. (1989) Metolachlor Field Dissipation Study in Iowa--Site B: Final Report: Lab Project Number 1265-B; 1265. Unpublished study prepared by Agrisearch Inc. 298 p.

41484201 Merricks, D. (1989) Metolachlor Fiel d Dissipation Study in Iowa-- Site A: Amendment to Final Report: Unpublished study prepared by Ciba-Geigy Corp. 6

p.

### 51 41484202 Merricks, D. (1989) Metolachlor Fiel d Dissipation Study in Iowa-- Site A: Amendment to Final Report. Unpublishe d study prepared by Ciba-Geigy Corp. 6

p.

41484203 Merricks, D. (1989) Metolachlor Fiel d Dissipation Study in Iowa-- Site B: Amendment To Final Report. Unpublishe d study prepared by Ciba-Geigy Corp. 7

p.

41484204 Merricks, D. (1989) Metolachlor Fiel d Dissipation Study in Iowa-- Site B. Unpublished study prepared by Ciba-Geigy Corp. 7 p.

41484205 Merricks, D. (1989) Metolachlor Field Di ssipation Study in Cali- fornia--Site C: Amendment to Final Report. Unpublishe d study prepared by Ciba-Geigy Corp. 6

p.

41484206 Merricks, D. (1989) Metolachlor Field Di ssipaation Study In Ca lifor nia--Site C: Amendment to Final Report. Unpublished st udy pre- pared by Ciba-Geigy Corp. 6

p.

43267304 Balu, K.; Smith, J.; Nelson, D. (1994) Res ponse to EPA Review of the Terrestrial Field Dissipation Studie s on Metolachlor: Lab Project Number: ABR-94023: 130000. Unpublished study prepared by Ciba-Geigy Corp. 49 p.

40114402 Honeycutt, R. (1986) Terre strial Dissipation of Metolachlor (Dual): Laboratory Study No. EIR-86031. Unpublished study prep ared by Ciba-Geigy Corp. 754 p.

67894 Ellgehausen, H.; Guth, J.A.; Esser, H.O. (1978) Factors Determining the Bioaccumulation Potential of Pesticides in the Individual Compartments of Aquatic Food Chains. (Unpublished st udy re- ceived Jan 28, 1981 under 100-618; prepared by Ciba-Geigy, Ltd., Switz erland, submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:244270-B)

126717 Dickson, G. (1983) Environmental Impact of Technical CGA-112913 under Specified EUP Conditions: Report No. EIR-83006. (Unpub- lished study received Apr 4, 1983 under 100-EX-79; submitted by Ciba-Geigy Corp., Greensboro, NC; CDL:249870-A; 249871)

40494607 Surprenant, D. (1988) Bioconcentration and Elimination of ?Carbon 14|-Residues by Bluegill (Lepomis macrochirus) E xposed to Metolachlor: Laboratory Study No. 87-9-2505. Unpublished study prepared by Springborn Life Sciences, Inc. 64

p.

41154201 Fackler, P. (1989) Bioconcentration a nd Elimination of ?Carbon 14| Residues by Bluegill (Lepomis macrochirus) Exposed to Metola- chlor: Laboratory Report No. 87-9-2505. Unpublished study pre- pared by Springborn Life Sciences, Inc. 188 p.

41523601 Fackler, P. (1989) Metolachlor: Am endment to the Final Report: Bioconcentration and Elimination of ?car bon 14| Residues by Blue- gill (Lepomis macro-chirus) Exposed to Metolachlor: Lab Project No: ABR-89019. Unpublished study prepared by Sprin gborn Labora- tories, Inc. 105 p.

### 52 16298 Barrows, M.E. (1974) Research report submitted to Ciba-Geigy Corporation: Exposure of fish to 14C-CGA-24705: Accu mulation, distribution, and elimination of 14C-residues. Unpublished study received Mar. 27, 1975 under 5F1606; prepared by Bionomics, EG&G Environm ental Consultants, submitted by CibaGeigy Corporation, Greensboro, NC; CDL: 094376-R.

44002501 Fuhrman, J. (1996) Analytical Method De velopment and First Year Performance: GC/MS Analytical Methodology to S upport the Acetochlor Registration Partnership Surface Water and Ground Water Monitoring Studies: Progress Report: Lab Project Number: MS L-14562: M001/1: ACET-95-GW-02. Unpublished study prepared by Ceregen, a Unit of Monsanto Co. 344 p.

44226601 Alexander, S.; Klein, T.; Stone, C.; et al. (1996) A Small Scale Prospective Groundwater Monitoring Study for Meto lachlor (Dual) at a Worst-Case

Vulnerable Site in Southeastern United States: Progress Report #6: Lab Project Number: 276-93: 93101. Unpublished study prepared by Stone Environmental Inc.; Research Options, Inc.; and Ciba Crop Protection. 33 p. (Relates to I004412).

44262101 Alexander, S.; Stone, C.; Gold, B. (1997) A Small Scale Prospective Groundwater Monitoring Study for Metolachlor (Dual) at a Worst-Case Vulnerable Site in Southeastern United States: Progress Report #7: Lab Proj ect Number: 276-93: 93101. Unpublished study prepared by Stone Environmental, Inc., Research Options, Inc., Novartis Crop Protection, Inc. 41 p.

44333901 Alexander, S.; Stone, C.; Gold, B. (1997) A Small Scale Prospective Groundwater Monitoring Study for Metolachlor (Dual) at a Worst-Case Vulnerable Site in Southeastern United States: Progress Report #8: Lab Proj ect Number: 276-93: 93101. Unpublished study prepared by Research Options, Inc.; Stone Environmental, Inc.; and Novar tis Crop Protection, Inc. 40 p.

44333902 Keen, K. (1997) A Small-Scale Prosp ective Groundwater Monitoring Study for

CGA-77102 at a Worst-Case Vulnerable Si te in the Midwestern United States: Progress Report #4: Lab Project Nu mber: 656-95: SG-954850. Unpublished study prepared by Summit Envirosolutions, Inc. and Novartis Crop Protection, Inc. 30 p.

44424501 Keen, K. (1997) A Small-Scale Prosp ective Ground Water Monitoring Study for

CGA-77102 at a Worst-Case Vulnerable Si te in the Midwestern United States: Progress Report #5: Lab Project Nu mber: 656-95: SG-954850. Unpublished study prepared by Summit Envirosolutions, Inc. 53 p.

44424502 Alexander, S.; Stone, C.; Gold, B. (1997) A Small-Scale Prospective Ground Water Monitoring Study for Metolachlor (Dual) at a Worst-Case Vulnerable Site

in the Southeastern United States: Pr ogress Report #9: Lab Project Number: 276- 93: 93101. Unpublished study prepared by Stone Environmental, Inc. and Research Options, Inc. 40 p.

### 53 44483701 Keen, K. (1998) A Small-Scale Prosp ective Ground Water Monitoring Study for

CGA-77102 at a Worst-Case Vulnerable Si te in the Midwestern United States: Progress Report #6: Lab Project Nu mber: 656-95: SG-954850. Unpublished study prepared by Summit Envirosolutions, Inc. and Novartis Crop Protection, Inc. 49 p.

44483702 Alexander, S.; Stone, C.; Gold, B. (1998) A Small Scale Prospective Groundwater Monitoring Study for Metolachlor (Dual) at a Worst-Case Vulnerable Site in Southeastern United States: Progress Report #10: Lab Project Number: 276-93: 93101. Unpublished study prepared by Stone Environmental, Inc., Research Options, Inc. and Novartis Crop Protection, Inc. 34 p.

44545401 Alexander, S.; Stone, C.; Gold, B. (1998) A Small Scale Prospective Groundwater Monitoring Study for Metolachlor (Dual) at a Worst-Case Vulnerable Site in Southeastern United States: Progress Report #11: Lab Project Number: 276-93: 93101. Unpublished study prepared by Nova rtis Crop Protection, Inc., Stone Environmental, Inc., and Re search Options, Inc. 37 p.

44545402 Keen, K. (1998) A Small-Scale Prosp ective Ground Water Monitoring Study for

CGA-77102 at a Worst-Case Vulnerable Si te in the Midwestern United States: Progress Report #7: Lab Project Nu mber: 656-95: SG-954850. Unpublished study prepared by Novartis Crop Protection, Inc., and Summit Envirosolutions, Inc. 48

p.

44619901 Alexander, S.; Stone, C.; Gold, B. (1998) A Small Scale Prospective Groundwater Monitoring Study for Metolachlor (Dual) at a Worst-Case Vulnerable Site in Southeastern United States: Lab Project Number: 276-93: 93101. Unpublished study prepared by Stone Envi ronmental, Inc., Novartis Crop Protection, Inc. and Research Options, Inc. 29 p.

44619902 Keen, K. (1998) A Small Scale Prosp ective Groundwater Monitoring Study for

CGA-77102 at a Worst-Case Vulnerable Si te in the Midwestern United States: Progress Report #8: Lab Project Nu mber: 656-95: SG-954850. Unpublished study prepared by Summit Envirosolutions, Inc. and Novartis Crop Protection, Inc. 54 p.

44687801 Alexander, S.; Stone, C.; Gold, B. (1998) A Small Scale Prospective Groundwater Monitoring Study for Metolachlor (Dual) at a Worst Case Vulnerable Site in Southeastern United States: Progress Report #13: Lab Project Number: 276-93: 93101. Unpublished study prepared by Stone Environmental, Inc. and Research Options, Inc. 30 p.

44687802 Keen, K. (1998) A Small Scale Prosp ective Groundwater Monitoring Study for

CGA-77102 at a Worst-Case Vulnerable Si te in the Midwestern United States: Progress Report #9: Lab Project Nu mber: 656-95: SG-954850. Unpublished study prepared by Summit Envirosolutions, Inc. and Novartis Crop Protection, Inc. 54 p.

44754001 Keen, K. (1999) A Small-Scale Prosp ective Ground Water Monitoring Study for

CGA-77102 at a Worst-Case Vulnerable Si te in the Midwestern United States: Progress Report #10: Lab Project Nu mber: 65-95: SG-954850. Unpublished study prepared by Summit Envirosolutions, Inc. and Novartis Crop Protection, Inc. 46 p.

### 54 44837101 Keen, K. (1999) A Small-Scale Prosp ective Ground Water Monitoring Study for

CGA-77102 at a Worst-Case Vulnerable Si te in the Midwestern United States: Interim Report: Progress Report No. 11: Lab Project Number: 656-95: SG954850. Unpublished study prepared by Summit Envirosolutions, Inc. 45 p.

44898101 Keen, K. (1999) A Small-Scale Prosp ective Ground Water Monitoring Study for

CGA-77102 at a Worst-Case Vulnerable Si te in the Midwestern United States: Lab Project Number: SG -954850: 656-95. Unpublished study prepared by Summit Envirosolutions, Inc., and Novar tis Crop Protection, Inc. 46 p.

45316601 Hackett, A. (2000) ARP SWM Program An alytical Results of the ARP Program Year 2000 through August for Parent He rbicides and Year 2000 Samples Analyzed to Date for Degradates: Lab Project Number: SWM1100. Unpublished study prepared by Monsanto Company. 81 p.

45840501 Jenkins, D.; Kelley, J.; Peterson, R. (2002) A Small Scale Prospective Groundwater Monitoring Study for Metol achlor: Lab Project Number: 02-110. Unpublished study prepared by Research Options, Inc., Kelley Consulting Geology, Agvise Laboratories and Ha rbor QA Services, Inc. 17 p.

45903901 Jenkins, D.; Kelley, J.; Peterson, R. (2003) A Small Scale Prospective Groundwater Monitoring Study for Metol achlor: Lab Project Number: 02-110. Unpublished study prepared by Research Options, Inc. and Enviro-Test Laboratories, Inc. 20 p.

45940701 Jenkins, D.; Kelley, J.; Peterson, R. (2003) A Small Scale Prospective Groundwater Monitoring Study for Metol achlor: Lab Project Number: 02-110: MN-18-WW-1. Unpublished study prepared by Research Options, Inc., EnviroTest Laboratories, Inc. and Agvise Laboratories. 93 p.

45943601 Jenkins, D.; Kelley, J.; Peterson, R. (2003) A Small Scale Prospective Groundwater Monitoring Study for Metol achlor: Lab Project Number: 02-110. Unpublished study prepared by Research Op tions, Inc., Agvise Laboratories, and Enviro-Test Laboratories, Inc. 93 p.

46029801 Vargo, J. (1998) Determination of Metolachor (CGA-24705) And CGA-77102, and Their Degradates CGA- 51202, CGA-354743, CGA- 380168, CGA-37735, CGA-67125, and CGA-41638 in Water by High Performance Liquid Chromatography with Mass Spectrometric Detection Includi ng Validation Data. Project Number: AG/682, 68/98. Unpublishe d study prepared by Syngenta Crop Protection, Inc. 150 p.

46185701 Jenkins, D.; Kelley, J.; Peterson, R. (2004) A Small Scale Prospective Groundwater Monitoring Study for Meto lachlor. Project Number: 02/110, MN/18/WW/1, DY/55/TH1. Unpublished st udy prepared by Research Options, Inc., Kelly Consulting Geology, and Harbor QA Services, Inc. 214 p.

### 55 46330301 Jenkins, D.; Kelley, J.; Peterson, R. (2004) A Small Scale Prospective Groundwater Monitoring Study for Metol achlor: Progress Report 2 - Sample Collection and Site Monitoring Through 186 Days After Treatment. Project Number: 02/110. Unpublished study prepared by Research Options, Inc., EnviroTest Laboratories (ETL) and Agvise Inc. 190 p.

46486201 Jenkins, D.; Kelley, J.; Peterson, R. (2005) A Small Scale Groundwater Monitoring Study for Metolachlor: Progre ss Report 3 - Sample Collection and Analysis Through 269 Days After Treatment. Project Number: 02/110. Unpublished study prepared by Research Options, Inc., Enviro-Test Laboratories, and Agvise Laboratories. 197 p.

46691001 Jenkins, D.; Kelley, J.; Peterson, R. (2005) A Small Scale Prospective Groundwater Monitoring Study for Meto lachlor. Project Number: 02/110. Unpublished study prepared by Research Options, Inc., Kelly Consulting Geology and Harbor QA Services, Inc. 257 p.

46734201 Jenkins, D.; Kelley, J.; Peterson, R. (2006) A Small Scale Prospective Groundwater Monitoring Study for Meto lachlor. Project Number: 02/110. Unpublished study prepared by Research Options, Inc., Kelly Consulting Geology and Harbor QA Services, Inc. 256 p.

46837601 Jenkins, D.; Kelley, J.; Peterson, R. (2006) A Small Scale Prospective Groundwater Monitoring Study for Meto lachlor Progress Report 6 - Sample Collection and Analysis Through 939 Days After Treatment. Project Number: 02/110. Unpublished study prepared by Re search Options, Inc., Enviro-Test Laboratories (ETL) and Har bor QA Services, Inc. 276 p.

46837602 Jenkins, D.; Kelley, J.; Peterson, R. (2006) A Small Scale Prospective Groundwater Monitoring Study for Metol achlor: Termination Request Report. Project Number: 02/110. Unpublished study prepared by Research Options, Inc., Enviro-Test Laboratories (ETL) a nd Agvise Laboratories. 22 p.

44002501 Fuhrman, J. (1996) Analytical Method De velopment and First Year Performance: GC/MS Analytical Methodology to S upport the Acetochlor Registration Partnership Surface Water and Ground Water Monitoring Studies: Progress Report: Lab Project Number: MS L-14562: M001/1: ACET-95-GW-02. Unpublished study prepared by Ceregen, a Unit of Monsanto Co. 344 p.

44136501 Cheung, M. (1996) Metolachlor Residue s in Ground Water from Ciba/State Ground Water Monitoring Studies in the Un ited States of America: Interim Report No. 1: Lab Project Number: 91-01: ABR-96041: 101921. Unpublished study prepared by Ciba-Geigy Corp. 276 p.

45058801 Cheung, M. (2000) FIFRA Section 6(a)(2) Annual Ground Water Report for the Year 1999. Unpublished study prepared by Novartis Crop Protection, Inc. 23 p.

45058802 Cheung, M. (2000) FIFRA Section 6(a)(2) Annual Surface Water Report for the Year 1999. Unpublished study prepared by Novartis Crop Protection, Inc. 15 p.

### 56 45449601 Guzman, N. (2001) State Ground Water Mo nitoring Program fo r Acetochlor and

Other Corn Herbicides--Part 7: 2000 Progress Report: Lab Project Number: 852- 562: ACET-95-GW-02: 3276.101. Unpublished study prepared by LFR LevineFricke, Monsanto, and Dow AgroSciences LLC. 15 p.

45629801 Yokley, R. (2002) FIFRA Section 6( a)(2) Annual Ground Water Report for 2001. Unpublished study prepared by HAES Re sources Department, Syngenta Crop Protection, Inc. 33 p.

45870401 Yokley, R. (2003) FIFRA Section 6( a)2 Annual Ground Water Report for 2002: Final Report: Lab Project Number: 2240-02. Unpublished study prepared by Syngenta Crop Protection, Inc. 34 p.

46839502 ECM Method Chemistry repot 2006 Ro lando Pet-ez, Jerry Allen, Sung-Ben Huang,Thomas Mayer, Steven Perez, Robert Yokley, Novem'jer 1 1, 2005, "Analytical Method

TO1 0097-04 for the Determinatiol? ofAtrazine, Si~n azi~!Ge-,3 0033, G-28279, G-28273,Ametryn, Prometryn, GS-11354, GS-11355, GS-26831 and Metolachlor in Water Using Direct lrzjection LC-ESL:iVS/MS lncllrding Validation Iata. "

47017401 Jenkins, D.; Kelley, J.; Peterson, R. (2006) A Small Scale Prospective Groundwater Monitoring Study for Metolach lor: Final Report. Project Number: 02/110, MW-U. Unpublished study prepared by Research Options Inc, ALS Laboratory Group and Environmen tal and Agvise Inc. 1490 p.

45527501 Tierney, D.P., et al. (2001) Exposure An alysis of Metolachlor in Community Water System in 27 States, 1993-2000, volume 1-5. Syngenta Crop Protection Report No. 2454-01. Unpublished study performed and submitted by Syngenta Crop Protection, Inc., Greensboro, NC and En fate, LLC, Plymouth, MN.

45533102 Chen, Wenlin and T.L. Estes (2001 ) PRZM3.12 Comparative Modeling of SMetolachlor and Metolachlor Based on Calibration Using Prospective

Groundwater Studies in Ge orgia and Minnesota. Synge nta Crop Protection Report No. 2501-01. Unpublished study performe d and submitted by Syngenta Crop Protection, Inc., Greensboro, NC and Stone Environmental Inc., Montpelier, VT

43766502 Hewitt, A. (1995) Spray Drift Task Force: Atomization Droplet Size Spectra for Selective Active Ingredie nts: Lab Project Number: A92/004. Unpublished study prepared by SpraySearch- Daratech Pty. Lt d. and Spray Drift Task Force. 175 p.

Environmental Fate Studies (S-Metolachlor)

43928935 Merritt, A. (1995) Photodegradation of (carbon 14)-Metolachlor and (carbon 14)-CGA77102 on Soil Under Artificial Sunligh t: Lab Project Number: ABR-95128: 53-95. Unpublished study prepared by Ci ba Crop Protection. 151 p. 4 p.

### 57 43928936 Clark, A. (1995) Comparative Aerobic Soil Metabolism of Phenyl-(carbon 14)-CGA77102 and Phenyl-(carbon 14)-Metolachlor: Lab Project Number: ABR-95102: 338- 94: 12217. Unpublished study prepared by Ciba Crop Protection and Agrisearch, Inc. 314 p.

44043401 Clark, A. (1995) Comparative Aerobic Soil Metabolism of Phenyl-(carbon 14)-CGA77102 and Phenyl-(carbon 14)-Metolachlor: Report Amendments 1,2,3: Lab Project Number: ABR-95102: 338-94. Unpublished study prepared by Ciba-Geigy Corp. 9 p.

45499606 Moore, P. (2000) Soil Metabolism of (Carbon 14)-Phenyl-CGA-77102 Under Aerobic and Non-Irradiated Incubation Conditions Following Surface and Homogeneous Dosing: Final Report: Lab Project Nu mber: 342-97. Unpublished study prepared by Novartis Crop Protection, Inc. 188 p.

43928937 Spare, W. (1995) Adsorption/Desorp tion of (carbon 14)-CGA-77102 by the Batch Equilibrium Method on Representative Agricu ltural Soils: Lab Project Number: 12218. Unpublished study prepared by Agrisearch, Inc. 179 p.

43928938 Spare, W. (1995) Leaching Characteristi cs of Aged (carbon 14)-CGA-77102 in Four Soil Types: Lab Project Number: 12216. U npublished study prepared by Agrisearch, Inc. 539 p.

44931722 Spare, W. (1997) Adsorption/Desorpti on of (carbon-14-CGA-354743) By the Batch Equilibrium Method on Representative Agricu ltural Soils: Lab Project Number: 92-97: 12240. Unpublished study prepared by Agrisearch, Inc. 252 p.

45608301 Ellgehausen, H. (1997) Adsorption/Deso rption of CGA-77102 in Various Soils: Final Report: Lab Project Number: 97EH01: 851-97. Unpublished study prepared by Novartis Crop Protection AG. 70 p.

45848001 Merritt, A. (2002) Dissipation of CGA-77102 in Soil Under Field Conditions with and without Turf (Bare Soil) in Georgia: Final Report: Lab Project Number: 51-99: 51-99 PART A: PM9901. Unpublished study prepared by Syngenta Crop Protection, Inc. 464

p.

46829512 Vargo, J.; Rezaaiyan, R. (1999) Analytical Method for the Determination of CGA77102 and Degradates CGA- 51202, CGA-354743, and CGA-37735 in Soil and Thatch, and CGA-77102 in Grass by High Performa nce Liquid Chromatography With Mass Spectrometric Detection. Project Numb er: 127/99. Unpublished study prepared by Syngenta Crop Protection, Inc. 76 p.

44226602 Keen, K. (1997) A Small Scale Prosp ective Ground Water M onitoring Study for CGA77102 at a Worst-Case Vulnerable Site in the Midwestern United States: Progress Report #2: Lab Project Number: 656-95: SG-954850. Unpublished study prepared by Summit Envirosolutions, Inc. and Ciba Crop Protection. 43 p.

44262102 Keen, K. (1997) A Small Scale Prospec tive Ground Water Mon itoring Study for CGA77102 at a Worst-Case Vulnerable Site in the Midwestern United States: Progress Report #3: Lab Project Number: SG- 954850: 656-95. Unpublished study prepared by Summit Envirosolutions, Inc. and N ovartis Crop Protection, Inc. 40 p.

### 58 45533101 Francis, P.; Johnson, B. (2001) A Small-Scale Prospective Ground Water Monitoring Study for Herbicide S-Metolachlor (CGA-77102) at a Worst-Case Vulnerable Site in

the Midwestern United States: Final Re port: Lab Project Number: 656-95: SG-954850. Unpublished study prepared by Summit Envirosolutions, Inc. 570 p.

45533102 Chen, W.; Estes, T. (2001) PRZM3.12 Comp arative Modeling of S-Metolachor and Metolachlor Based on Calibration Using Pros pective Groundwater Studies in Georgia and Minnesota: Final Report: Lab Pr oject Number: 2501-01. Unpublished study prepared by Stone Environmental Inc. 82 p.

46029801 Vargo, J. (1998) Determination of Metolachor (CGA-24705) And CGA-77102, and Their Degradates CGA-51202, CGA-354743, CGA-380168, CGA-37735, CGA67125, and CGA-41638 in Water by High Perf ormance Liquid Chromatography with Mass Spectrometric Detection Including Validation Data. Project Number: AG/682, 68/98. Unpublished study prepared by Syngenta Crop Protection, Inc. 150 p.

44527503 Chen, Wenlin, 200 1. Concentration Trend of Metolachlor and S-Metolachlor Resulting from the Reduced Use Rate of S-Me tolachlor in Ohio Lake Erie Tributary Drainage Basins. Syngenta Crop Praec tion Report No. 1663-0 1. Unpublished study performed and submitted by Syngenta Cr op Protection, Inc., Greensboro, NC.

Registrant Summary of adsorption Studies 1978-1987 with Metolachlor

44303502 Murphy, T.; Clark, A.; Merritt, A. (19 97) Response to EPA Review of CGA77102/Metolachlor Environmental Fate St udies: Lab Projec t Number: ABR-97049. Unpublished study prepared by Novartis Crop Protection, Inc. 45 p.

45499601 Needham, J.; Brady, J. (1999) Analytic al Method for th e Semi-Quantitative Determination of CGA-77102 in Water by En zyme Immunoassay Including Validation Data: Lab Project Number: 1004-98. Unpub lished study prepared by Novartis Crop Protection, Inc. 40 p.

45499602 Meyer, L. (2001) An Assessment of th e Toxicological Profiles of Two Major Environmental Degradates of S-Metolachlo r (Ethane Sulfonic Acid and Oxanilic Acid) and a Rationale for Establishing Separating Drinking Water Standards: Final Report: Lab Project Number: 2121-01. Unpublished study prepared by Syngenta Crop Protection, Inc. 56 p.

45527502 Tierney, D.; Marut, K.; Dando, C. et al. (2001) Occurrence of Me tolachlor (1994-1995) Compared to S-Metolachlor (1999-2000) in Drinking Water From Community Water Systems in 27 Major Use States: Lab Project Number: 2455-01: 00025. Unpublished study prepared by Syngenta Crop Protection, Inc. 23 p.

45527503 Chen, W. (2001) Concentration Trend of Metolachlor and S-Me tolachlor Resulting

from the Reduced Use Rate of S-Metolachor in Ohio Lake Erie Tributary Drainage

### 59 Basins: Final Report: Lab Project Nu mber: 1663-00. Unpublished study prepared by Syngenta Crop Protection, Inc. 96 p.

45672301 Hipps, A. (2002) Physical and Chemical Properties of S-Metolachlor (CGA-77102) Technical: Lab Project Number: PC-02-035. Unpublished study prepared by Syngenta Crop Protection, Inc. 23 p. {OPPTS 830.7050}

46224201 Trask, J.; Harbourt, C.; Johnson, L.; et. al . (2003) 2001 S-Metolachlor Monitoring Data for Community Water Systems in 29 St ates: Final Report. Project Number: WEI/242/59/001, T001594/03, 242/59/001. Unpublished study prepared by

Waterborne Environmenta l, Inc. (WEI). 1775 p.

45527501 Tierney, D.; Marut, K.; Dando, C. et al. ( 2001) Exposure Analysis of Metolachlor in Community Water Systems in 27 Use St ates, 1993-2000: Lab Project Number: 2454- 01: 00024. Unpublished study prepared by S yngenta Crop Protection, Inc. 1771 p.

46224202 Trask, J.; Harbourt, C.; Johnson, L.; et. al . (2003) 2002 S-Metolachlor Monitoring Data for Community Water Systems in 43 St ates: Final Report. Project Number: WEI/242/59/002, 242/59/002, T001596/03. Unpublished study prepared by

Waterborne Environmenta l, Inc. (WEI). 1785 p.

46484201 Merritt, A. (2005) FIFRA Section 6(a)(2 ) Annual Report for S-Me tolachlor Monitoring Data from the 2004 Atrazine Monitoring Program (AMP) for Selected Community Water Systems (CWS) on Surface Water Sources: S-Metolachlor: Final Report. Project Number: T003232/05. Unpublished study prepar ed by Syngenta Crop Protection, Inc. 64 p.

46818801 Indergand, P.; Nicollier, G. (2006) Producti on and Analysis of Leachates in Outdoor Lysimeters Treated with [Phenyl-U-(Car bon 14)]-CGA 77102: Final Report. Project Number: 02GN05, T003712/02. Unpublished study prepared by Syngenta Crop Protection, AG. 232 p.

47067701 Perez, R.; Merritt, A.; Perez, S. (2007) S-Metolachlor: FIFRA Section 6(a)(2) Annual Report for S-Metolachlor M onitoring Data from the 2006 Atrazine Monitoring Program, 2006 Simazine Monitoring Progr am and 2006 Simazine Confirmatory Monitoring Program for Selected Commun ity Water Systems Relying on Surface Water Sources: Final Report. Pr oject Number: 2K6/901/0766/06/02, T000766/06. Unpublished study prepared by ADPEN Laboratories, Inc. 18 p.

47358801 Perez, R.; Perez, S.; Merritt, A. (2008) S-Metolachlor FIFRA Section 6(a)(2) Annual Report for S-Metolachlor M onitoring Data from the 2007 Atrazine Monitoring Program, 2007 Simazine Monitoring Pr ogram, 2007 Simazine Confirmatory Monitoring Program and 2007 Stewardshi p Voluntary Monitoring Program for Selected Community Water Systems Relyi ng on Surface Water Sources: Final Report. Project Number: 2K7/901/766/06/01. Unpublished study prepared by ADPEN Laboratories, Inc. 18 p.

### 60 46029802 Yodley, R.A. and M.W. Cheung (2002) Syngenta/Community Water System Surface Water Monitoring Study for Atrazine and its Major Degradation Products in Seven States in the United States (Suppl emental to EPA MRID 45058703 and MRID 45145601); Supplementary Report 2 – Data for Metolachlor and its Major Metabolites (ESA and OA). Syngenta Crop Protection Report 419-97. Unpublished study performed and submitted by Syngenta Cr op Protection, Inc., Greensboro, NC.

46029801 Vargo, J. (1998) Determination of Metolachor (CGA-24705) And CGA-77102, and Their Degradates CGA-51202, CGA-354743, CGA-380168, CGA-37735, CGA67125, and CGA-41638 in Water by High Perf ormance Liquid Chromatography with Mass Spectrometric Detection Including Validation Data. Project Number: AG/682, 68/98. Unpublished study prepared by Syngenta Crop Protection, Inc. 150 p.

Cited Ecological Effects Studi es Ecological Effects Studies

00015523 Bathe, R. (1973) Acute Oral LD-50 of Technical CGA-24705 in the Rat: Project No. Siss 2979. Received September 26, 1974 under 5G1553. (Unpublished report prepared by CIBA-GEIGY Ltd., Ba sle, Switzerland; CDL: 112840-A

00015534 Sachsse, K.; Ullmann, L. (1974) Acute T oxicity to Rainbow Trout, Crucian Corp, Channel Catfish, Bluegill and Guppy of Technical CGA-24705: Project No. Siss 3516. (Unpublished study received Mar 1, 1974 under 5G1553; prepared by CibaGeigy, Ltd., submitted by Ciba-Geigy Co rp., Greensboro, N.C.; CDL:094220-M)

00015546 Vilkas, A.G. (1976) Acute Toxicity of CGA-24705 Technical to the Water Flea, Daphnia magna Straus. (Unpublished study received Nov 24, 1976 under 100- 587; prepared by Union Carbide Corp., submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:226955-E)

00015547 Fink, R. (1976) Final Report: Acute Oral LD50--Mallard Duck: Project No. 108- 117. (Unpublished study received Nov 24, 1976 under 100-587; prepared by Truslow Farms, Inc. in cooperation with Maryland, Dept. of Ag riculture, Division of Inspection and Regulation, submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL: 226955-F)

00016425 Fink, R. (1974) Final Report: Eight-Day Dietary LC50--Mallard Ducks: Project No. 108-111. (Unpublished study received on un- known date under 5G1553; prepared by Truslow Farms, Inc. in cooperation with Maryland, Dept. of Agriculture, Div. of Inspection and Regulation, submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:094220-O)

00016426 Fink, R. (1974) Final Report: Eight-Day Dietary LC50--Bobwhite Quail: Project No. 108-110. (Unpublished study received on unknown date under 5G1553; prepared by Truslow Farms, Inc. in cooperation with Maryland, Dept. of

### 61 Agriculture, Div. of Inspection and Regulation, submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:094220-P)

00018722 Buccafusco, R.J.; Stiefel, C.; Sullivan, D.M.; et al. (1978) Acute Toxicity of CGA-24705 to Rainbow Trout ( Salmo gairdneri ): Report #BW-78-6-186. (Unpublished study received Jul 13, 1 978 under 100-597; prepared by EG&G, Bionomics, submitted by Ciba- Geigy Co rp., Greensboro, N.C.; CDL:234396-B)

00018723 Buccafusco, R.J.; Stiefel, C.; Sullivan, D.M. (1978) Acute Toxicity of CGA24705 to Bluegill ( Lepomis macrochirus ): Report #BW- 78-6-181. (Unpublished study received Jul 13, 1978 under 100- 597; prepared by EG&G, Bionomics, submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:234396-C)

00062465 Fink, R.; Beavers, J.B.; Brown, R.; et al . (1981) Final Report: Acute Oral LD50-- Mallard Duck: Project No. 108-200. (Unpublished study received Mar 31, 1981 under 100-587; prepared by W ildlife International, Ltd. and Washington College, submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:244691-B)

00162292 Beavers, J. (1978) One Generati on Reproduction Study - Mallard Duck: Metolachlor Technical (CGA - 24705): Final Report. Un- published study prepared by Wildlife International Ltd. 29 p.

43044602 Ward, S. (1980) Metolachlor: Effects of metolachlor (Dual) on Survival, growth, and Development of Sheepshead Minnow ( Cyprinodon variegatus ): Lab Project Number: BP-80-5-80: L33. Unpublished study prepared by EG&G Bionomics, Marine Research Lab. 32 p.

43487101 Machado, M. (1994) Metolachlor Tec hnical--Acute Toxicity to Sheepshead Minnow ( Cyprinodon variegatus ) Under Flow-through Conditions: (Final Report): Lab Project Number: 94-7-5378: 1781.0394.6422.505. Unpublished study prepared by Springborn Labs, Inc. 70 p.

43487102 Dionne, E. (1994) Metolachlor Technical --Acute Toxicity to Eastern Oyster ( Crassostrea virginica ) Under Flow-through Conditions: (Final Report): Lab Project Number: 94-7-5365: 1781.0394.6423.504. Unpublished study prepared by Springborn Labs, Inc. 76 p.

43487103 Machado, M. (1994) Metolachlor Techni cal--Acute Toxicity to Mysid Shrimp ( Mysidopsis bahia ) Under Flow-through Conditions: (Final Report): Lab Project Number: 94-7-5402: 1781.0394.6421.515. Unpublished study prepared by Springborn Labs, Inc. 75 p.

43487104 Hoberg, J. (1994) Metolach lor Technical--5-Day Toxicity to the Freshwater Green Alga, Anabaena flos-aquae : (Final Report): Lab Pr oject Number: 94-7-5383: 1781.0394.6427.420. Unpublished study prepared by Springborn Labs, Inc. 65 p.

43487105 Hoberg, J. (1994) Metolachlor Te chnical--Toxicity to Duckweed ( Lemna gibba ): (Final Report): Lab Pr oject Number: 94-8-5404: 1781.0394.6428.410. Unpublished study prepared by Sp ringborn Labs, Inc. 71 p.

### 62 43487106 Hoberg, J. (1994) Metol achlor Technical--Toxicity to the Marine Diatom,

Skeletonema costatum : (Final Report): Lab Project Number: 94-7-5382: 1781.0394.6426.450. Unpublished study prepared by Springborn Labs, Inc. 67 p.

43487107 Chetram, R. (1994) Tier 2 Seedling Emergence Nontarget Phytotoxicity Study Using Metolachlor: Lab Project Nu mber: 94349. Unpublished study prepared by Pan-Agricultural Labs, Inc. 180 p.

43487108 Chetram, R. (1994) Tier 2 Vegetative Vigor Nontarge t Phytotoxicity Study Using Metolachlor: Lab Project Number: 9 4350. Unpublished study prepared by PanAgricultural Labs, Inc. 175 p.

43541301 Hoberg, J. (1995) Metolach lor Technical--5-Day Toxicity to the Freshwater Green Alga, Selenastrum capricornutum , Using Acetone as a Carrier Solvent: (Final Report): Lab Project Number : 94-12-5621: 1781.1294.6467.430. Unpublished study prepared by Springborn Labs, Inc. 68 p.

43541302 Hoberg, J. (1995) Metol achlor Technical--5-Day Toxi city to the Freshwater Diatom, Navicula pelliculosa , Using Acetone as a Carrier Solvent: (Final Report): Lab Project Number: 94-12- 5627: 1781.1294.6468.440. Unpublished study prepared by Springborn Labs, Inc. 68 p.

43802601 Putt, A. (1995) Metolachlor Technical--The Chronic Toxicity to Daphnia magna Under Flow-Through Conditions: Lab Project Number: 95-8-6061. Unpublished study prepared by Springborn Labs, Inc. 116 p.

44995903 Sousa, J. (1999) S-Metolachlor CGA-77102 --Early Life-Stage Toxicity Test with Fathead Minnow ( Pimephales promelas ): Final Report: Lab Project Number: 108- 99: 1781.6576. Unpublished study prepared by Springborn Labs., Inc. 79 p.

Relates to L0000473.

43928906 Beavers, J. (1983) An Acute Oral Toxi city Study in the Mallard with CGA 77102: Lab Project Number: 108-219. Unpublishe d study prepared by Wildlife International Ltd. 14 p.

43928907 Beavers, J. (1983) An Acute Oral T oxicity Study in the Bobwhite with CGA 77102: Lab Project Number: 108-220. Unpub lished study prepared by Wildlife International Ltd. 14 p.

43928908 Beavers, J. (1983) An Eight-Day Dietar y LC50 in the Bobwhite Quail with CGA 77102: Lab Project Number: 108-217. Unpub lished study prepared by Wildlife International Ltd. 13 p.

43928909 Beavers, J. (1983) An Eight-Day Di etary LC50 in Mallard Ducks with CGA 77102: Lab Project Number: 108-218. Unpub lished study prepared by Wildlife International Ltd. 14 p.

43928910 Spare, W. (1983) The Acute Toxic ity of CGA-77102 Technical to Bluegill Sunfish, Lepomis macrochirus : Lab Project Number: 83-E-168B. Unpublished study prepared by Biospherics, Inc. 16 p.

### 63 43928911 Collins, M. (1995) CGA-77102--Acute Toxicity to Rainbow Trout ( Oncorhynchus mykiss ) Under Static Conditions: (Final Re port): Lab Project Number: 95-9-6117: 1781.0495.6500.103. Unpublished study prepared by Springborn Labs, Inc. 68 p.

43928912 Collins, M. (1995) CGA 77102--Acute Toxicity to Daphnids ( Daphnia magna ) Under Static Conditions: (Final Repo rt): Lab Project Number: 95-9-6082: 1781.0495.6501.110. Unpublished study prepared by Springborn Labs, Inc. 68 p.

43928929 Hoberg, J. (1995) 5-Day Toxicity to the Freshwater Green Alga, Selenastrum capricornutum : CGA 77102: (Final Report): Lab Project Number: 95-8-6031: 1781.0495.6502.430. Unpublished study prepared by Springborn Labs, Inc. 69 p.

43928930 Hoberg, J. (1995) 5-Day Toxi city to the Marine Diatom, Skeletonema costatum : CGA 77102: (Final Report): La b Project Number: 95-8-6062: 1781.0495.6504.450. Unpublished study prepared by Springborn Labs, Inc. 67 p.

43928931 Hoberg, J. (1995) Toxicity to Duckweed, Lemna gibba : CGA 77102: (Final Report): Lab Project Number: 95-8-6068: 1781.0495.6503.410. Unpublished study prepared by Springborn Labs, Inc. 71 p.

43928932 Chetram, R.; Schuster, L. (1995) Tier 2 Seedling Emergence Nontarget Phytotoxicity Study Usi ng CGA 77102: Lab Project Number: 95481. Unpublished study prepared by ABC Labs, Pan-Ag Div. 180 p.

43928933 Chetram, R.; Schuster, L. (1995) Tier 2 Vegetative Vigor Nontarget Phytotoxicity Study Using CGA 77102: Lab Project Number: 95482. Unpublished study prepared by ABC Labs, Pan-Ag Div. 152 p.

44015602 Taliaferro, L.; Taliaferro, M.; Miller, V. (1996) The Reproductive Toxicity Test of CGA-24705 (Metolachlor) in Mallard Ducks ( Anas platyrhynchos ): Lab Project Number: 029409. Unpublished study prepared by EBA, Inc. 262 p.

44718401 Bew, M.H. (1992) Acute Contact and Or al Toxicity of CGA-24705 to Honeybees. October 30, 1992. Laboratory: MAFF Central Science Laboratory, National Bee Unit, Warwickshire, England. Lab. St udy ID:CC06092. Novartis Crop Protection, Inc., Greensboro, NC

44718402 Candolfi, M. (1997) CGA-77102: Laborator y Oral and Contact Test with the Honeybee, Apis Mellifera : Metolachlor: Lab Project Number: 97-137-1008: 525- 96. Unpublished study prepared by Springborn Laboratories (Europe) AG. 42 p.

44929501 Vial, A. (1991) Report on the Acute Toxicity Test of CGA-51202 to Rainbow Trout ( Salmo gairdneri ): Final Report: Lab Project Number: 918150: 406-91. Unpublished study prepared by Ciba-Geigy Limited. 22 p.

44929502 Vial, A. (1991) Report on the Acute Toxicity Test of CGA-51202 to Common Carp ( Cyprinus carpio ): Final Report: Lab Pr oject Number: 918151: 407-91. Unpublished study prepared by Ciba-Geigy Limited. 20 p.

### 64 44929503 Vial, A. (1991) Report on the Ac ute Toxicity Test of CGA-51202 on ( Daphnia

magna Straus 1820): Final Report: La b Project Number: 918162: 405-91. Unpublished study prepared by Ciba-Geigy Limited. 23 p.

44929513 Schwab, D. (1997) Evaluating the E ffects of CGA-51202 on the Emergence and Vegetative Vigor of Non-Target Terrestrial Plants: Final Report: Lab Project Number: 43901: 230-97. Unpublished study pr epared by ABC Laboratories, Inc. 69 p.

44929514 Boeri, R.; Magazu, J.; Ward, T. (1997) Acute Toxicity of CGA-51202 to the Duckweed, Lemna Gibba G3: Final Report: Lab Project Number: 1233-NO: 231- 97. Unpublished study prepared by T.R. Wilbury Laboratories, Inc. 31 p.

44929515 Vial, A. (1991) Report on the Growth Inhibition Test of CGA-51202 to Green Algae ( Scenedesmus subspicatus ): Final Report: Lab Project Number: 918152: 408-91. Unpublished study prepared by Ciba-Geigy Limited. 23 p.

44931702 Rufli, H. (1996) Acute Toxicity Te st of CGA-354743 (Metab olite of CGA-24705) to Rainbow Trout ( Oncorhynchus mykiss ) in the Static System: Final Report: Lab Project Number: 961526: 489-96. Unpublished study prepared by Ciba-Geigy Ltd. 46 p.

44931703 Neumann, C. (1996) Acute Toxicity Test of CGA-354743 (Metabolite of CGA24705) to the Cladoceran ( Daphnia magna Straus) Under Static Conditions: Final Report: Lab Project Number: 961528: 488-96. Unpublished study prepared by Ciba-Geigy Ltd. 40 p.

44931718 Schwab, D. (1997) Evaluating the E ffects of CGA-354743 on the Emergence and Vegetative Vigor of Non- Target Terrestrial Plants : CGA-354743: Final Report: Lab Project Number: 43900: 229-97. Unpub lished study prepared by ABC Labs., Inc. 69 p.

44931719 Grade, R. (1997) Growth Inhibition Test of CGA-354743 (Metabolite of CGA24705) to Green Algae ( Selenastrum capricornutum ) Under Static Conditions: Lab Project Number: 971645: 784-97. Unpub lished study prepared by Ciba-Geigy Ltd. 51 p.

44931720 Ward, T.; Magazu, J.; Boeri, R. (1999) Toxicity of CGA-354743 to the Duckweed, Lemna gibba G3: Final Report: Lab Project Number: 1688-NO: 1145- 98. Unpublished study prepared by T.R. Wilbury Labs., Inc. 29 p.

44931721 Candolfi, M. (1997) 14-Day Acute Toxi city Test with the Earthworm ( Eisenia foetida ) Based on OECD Guideline #207: CGA-354743: Final Report: Lab Project Number: 97-162-1008: 527-9 6. Unpublished study prepared by Springborn Labs., AG. 47 p.

44995901 Kaczor, M.; Miller, V. (1999) The Re productive Toxicity Test of CGA-77102 Technical with the Northern Bobwhite ( Colinus virginianus ): Final Report: Lab Project Number: 029901: 193-99. Unpublished study prepared by EBA Inc. 305 p.

### 65 44995902 Lima, W. (1999) S-Metolachlor CGA- 77102--Life-Cycle Toxicity Test with Mysid ( Mysidopsis bahia ): Final Report: Lab Project Number: 106-99: 1781.6575. Unpublished study prepared by Springborn Labs., Inc. 81 p. Relates to

L0000473.

46322101 Palmer, S.; Kendall, T.; Krueger, H. (2004) Metolachlor Technical: A FlowThrough Life-Cycle Toxicity Te st with the Cladoceran ( Daphnia magna ): Final Report. Project Number: 568A/101A. U npublished study prepared by Wildlife International, Ltd. 61 p.

46508901 Temple, D.; Martin, K.; Beavers, J.; et. al. (2005) Metolachlor Technical: A Reproduction Study with the Northern Bobw hite: Final Report. Project Number: 568/102. Unpublished study prepared by W ildlife International, Ltd. 181 p.

46829506 Palmer, S.; Kendall, T.; Krueger, H. (2004) CGA-77102: A 96-Hour StaticRenewal Acute Toxicity Test with the Sheepshead Minnow ( Cyprinodon variegatus ): Final Report. Project Number: 528A/126, 240/02, 528/041603/SHE/96H2/SUB528. Unpublishe d study prepared by Wildlife International, Ltd. 62 p.

46829507 Palmer, S.; Kendall, T.; Krueger, H. (2004) CGA-77102: A Flow-Through LifeCycle Toxicity Test With the Cladoceran ( Daphnia Magna ). Project Number: 528A/130, 241/02, 528/041603/DAP/LC2/OEC D/OPPTS/sub528. Unpublished study prepared by Wildlife International, Ltd. 79 p.

46829509 Desjardins, D.; Kendall, T.; Krueger, H. (2003) CGA-77102: A 96-Hour Toxicity Test With the Freshwater Diatom ( Navicula pelliculosa ): Final Report. Project Number: 528A/129, 243/02, 528/041603/NAV96/OECD/OPPTS/SUB528. Unpublished study prepared by Wildlife International, Ltd. 69 p.

46829510 Desjardins, D.; Kendall, T.; Krueger, H. (2004) CGA-77102: A 96-Hour Toxicity Test With the Freshwater Alga ( Anabaena flos-aquae ): Final Report. Project Number: 528A/128A, 244/02, 528/0 41603/ANA/OECD/OPPTS/SUB528. Unpublished study prepared by Wildlife International, Ltd. 64 p.

### 66 

## Appendix A: Uses and Rate Table for Metolachlor/S-Metolachlor Labels

Use Method of Application Maximum Application Rate Per Crop Cycle (minimum application interval) 1


### Metolachlor (PC Code 108801) Beans Broadcast, chemigation, soil broadcast, soil incorporated 1 3 

### app at 2.0 lb ai/A

Corn (unspecified) Broadcast, soil broadcast 2 3 

### apps at 2.1 lb ai/A Broadcast, chemigation, soil broadcast, soil incorporated, soil treatment (surface) 1 3 

### app at 2.7 lb ai/A

Direct Spray 1 3 

### app at 1.6 lb ai/A Soil treatment NS apps at 1.8 lb ai/A Cotton (unspecified) Broadcast, soil broadcast 2 3 

### apps at 2.1 lb ai/A Chemigation, direct spray, soil band treatment, soil incorporated 3 2 

### apps at 1.3 lb ai/A

Peanuts (unspecified) Broadcast, soil broadcast NS apps at 2.0 lb ai/A Soil incorporated NS apps at 1.3 lb ai/A Peas (unspecified) Broadcast, chemigation, soil broadcast, soil incorporated 1 3 

### app at 2.0 lb ai/A

Potato, White/Irish (or unspecified) Broadcast, chemigation, soil broadcast, soil incorporated 1 2 

### app at 2.7 lb ai/A

Safflower (unspecified) Broadcast, chemigation, soil broadcast, soil incorporated NS apps at 2.0 lb ai/A

Sorghum (unspecified) Broadcast, chemigation, soil broadcast, soil incorporated, soil treatment (surface) 1 app at 1.7 lb ai/A

Soybeans (unspecified) Broadcast, chemigation, soil broadcast, soil incorporated 1 2 

### app at 2.7 lb ai/A

Soil treatment (surface) NS apps at 2.4 lb ai/A Tomato Direct spray, soil band treatment, soil broadcast, soil incorporated 1 3 

### app at 2.0 lb ai/A

S-Metolachlor (PC Code 108800) Caneberry subgroup 13A (blackberry and raspberry) Soil band treatment 1 2 

### app at 1.9 lb ai/A

Root vegetables subgroup 1B (except sugar beet) Broadcast, chemigation, soil broadcast, soil incorporated, soil treatment (surface) 1 2 

### app at 1.3 lb ai/A

Tuberous and corm vegetables subgroup

1C Broadcast, chemigation, soil broadcast, soil incorporated, soil treatment (surface) 1 2 

### app at 1.3 lb ai/A

Leafy Brassica greens subgroup 5B Broadcast, chemigation, soil

broadcast 1 2 

### app at 1.3 lb ai/A

Melon subgroup 9A Broadcast, chemigation, soil band, 1 2 

### app at 1.2 lb ai/A

### 67 soil broadcast Alfalfa Chemigation, soil broadcast NS apps at 3.2 lb ai/A Asparagus Broadcast, chemigation, soil band,

soil broadcast 1 2 

### app at 1.9 lb ai/A

Beans, beans (driedtype), beans (succulent, lima) Broadcast, chemigation, soil broadcast, soil incorporated 1 3 

### app at 1.9 lb ai/A

Beans (dried-type) Soil treatment 1 3 

### app at 1.9 lb ai/A Beets (green), beets (root), beets (unspecified) Broadcast, chemigation, soil broadcast, soil incorporated 1 2 

### app at 1.3 lb ai/A

Soil band 1 2 

### app at 0.64 lb ai/A Bell Peppers Broadcast 1 2 

### app at 0.95 lb ai/A Chemigation, soil treatment (surface), 1 2 

### app at 1.3 lb ai/A Direct spray, soil broadcast 1 2 

### app at 1.6 lb ai/A Blackberry Soil band, soil broadcast 1 2 

### app at 1.9 lb ai/A Blueberry Soil band 1 2 

### app at 1.3 lb ai/A Broccoli Broadcast, chemigation, soil

broadcast 1 2 

### app at 1.3 lb ai/A

Soil band NS apps at 1.2 lb ai/A Brussels sprouts Broadcast, chemigation, soil

broadcast 1 2 

### app at 1.3 lb ai/A

Bulb vegetables, Cabbage, Cabbage (Chinese),

Cauliflower Broadcast, chemigation, soil band,

soil broadcast 1 2 

### app at 1.3 lb ai/A

Carrot (Including Tops) Broadcast, chemigation, soil band,

soil broadcast 1 2 

### app at 1.9 lb ai/A

Celery Broadcast, chemigation, soil broadcast, soil incorporated 1 2 

### app at 1.9 lb ai/A

Direct spray 1 2 

### app at 1.3 lb ai/A Chard (swiss) Broadcast, chem igation 1 app at 1.3 lb ai/A Soil band, soil broadcast 1 2 

### app at 0.95 lb ai/A Coriander Broadcast, chemigation, soil

broadcast 1 2 

### app at 0.95 lb ai/A

Corn (silage) Soil band, soil treatment, soil treatment (surface) 1 2 

### app at 2.0 lb ai/A

Corn (unspecified) Band treatment, direct spray, impregnated dry bulk fertilizer, soil

treatment 1 3 

### app at 1.6 lb ai/A

Broadcast, chemigation, soil broadcast, soil incorporated, soil treatment (surface) 1 2 

### app at 2.5 lb ai/A

Soil band 1 3 

### app at 2.4 lb ai/A Corn (field) Broadcast, direct spray, soil band, soil treatment (surface) , soil treatment 1 2 

### app at 2.0 lb ai/A

### 68 Band treatment, Impregnated dry bulk fertilizer, soil incorporated 1 3 

### app at 1.8 lb ai/A

Corn (pop) Broadcast, soil band, soil treatment (surface) NS apps at 2.0 lb ai/A

Corn (sweet) Broadcast, soil band, soil treatment (surface) 1 2 

### app at 2.0 lb ai/A

Band treatment, impregnated dry bulk fertilizer, soil incorporated, 1 3 

### app at 1.8 lb ai/A

Cotton (unspecified) Broadcast, soil broadcast, soil

treatment 1 3 

### app at 1.6 lb ai/A

Chemigation, soil band, 2 3 

### apps at 1.3 lb ai/A

Direct spray, soil incorporated 2 2 

### apps at 1.3 lb ai/A

1 3 

### app at 1.3 lb ai/A Crops grown for oil Broadcast, soil broadcast, soil incorporated 1 2 

### app at 1.3 lb ai/A

Cucumber Broadcast, chemigation, soil

broadcast 1 2 

### app at 1.3 lb ai/A

Currant, Elderberry, Gooseberry, Huckleberry Soil band 1 2 

### app at 1.3 lb ai/A

Eggplant Broadcast, soil broadcast 1 2 

### app at 1.3 lb ai/A Garlic, Horseradish,

Leek Broadcast, chemigation, soil band,

soil broadcast 1 app at 1.3 lb ai/A

Grasses grown for

seed Chemigation, soil broadcas t 1 app at 1.3 lb ai/A

Leafy Vegetables Broadcast, chemigation, soil

broadcast 1 2 

### app at 1.3 lb ai/A

Direct spray 1 2 

### app at 0.64 lb ai/A Legume vegetables Broadcast, soil broadcast 1 app at 1.5 lb ai/A Lentils Broadcast, chemigation, soil broadcast, soil incorporated 1 3 

### app at 1.9 lb ai/A

Loganberry Soil band, soil broadcast 1 2 

### app at 1.9 lb ai/A Melons, melons (water) Broadcast, chemigation, soil band,

soil broadcast 1 2 

### app at 1.2 lb ai/A

Okra Chemigation, direct spray, soil band 1 2 

### app at 1.9 lb ai/A Onion Broadcast, chemigation, soil band,

soil broadcast 2 2 

### apps at 1.3 lb ai/A (21 days) Soil incorporated, soil treatment (surface) 1 2 

### app at 1.3 lb ai/A

Onions (green) Broadcast, chemigation, soil band,

soil broadcast 1 2 

### app at 1.3 lb ai/A

Ornamental

Herbaceous Plants Broadcast, chemigation, soil band,

soil broadcast 1 2 

### app at 1.2 lb ai/A

Ornamental Lawns and Turf, Ornamental Broadcast, chemigation, soil

broadcast 1 3 

### app at 2.5 lb ai/A

### 69 Sod Farm (Turf)

Ornamentals (unspecified) Band Treatment NDC Broadcast, chemigation, soil

broadcast 1 2,3 

### app at 2.5 lb ai/A

Parsnip Broadcast, chemigation, soil broadcast, soil incorporated 1 2 

### app at 1.3 lb ai/A

Peanuts (Unspecified) Broadcast, band, soil broadcast NS apps at 1.9 lb ai/A Soil incorporated, soil treatment (surface) NS apps at 1.3 lb ai/A

Peas (Unspecified) Broadcast, Chemigation, soil broadcast, soil incorporated 1 3 

### apps at 1.9 lb ai/A

Pepper Broadcast, chemigation 1 2 

### app at 0.95 lb ai/A Soil band, soil broadcast 1 2 

### app at 1.3 lb ai/A Pepper (Chili type) Direct spray, soil broadcast 1 2 

### app at 1.6 lb ai/A Potato, white/irish (or unspecified) Broadcast, chemigation, soil

broadcast 1 2 

### app at 2.5 lb ai/A

Soil incorporated 1 2 

### app at 1.9 lb ai/A Pumpkin Broadcast, chemigation, soil

broadcast 1 2 

### app at 1.3 lb ai/A

Soil treatment NS app at 1.3 lb ai/A Radish Broadcast, chemigation ,soil incorporated 1 2 

### app at 1.2 lb ai/A

Soil broadcast 1 3 

### app at 1.3 lb ai/A

Radish/Daikon (chinese), Rutabaga Broadcast, chemigation, soil broadcast, soil incorporated 1 2 

### app at 1.3 lb ai/A

Soil band 1 2 

### app at 0.64 lb ai/A Raspberry (black, red) Soil band, soil broadcast 1 2 

### app at 1.9 lb ai/A

Rhubarb Broadcast, chemigation, soil band,

soil broadcast 1 2 

### app at 1.3 lb ai/A

Safflower (unspecified) Broadcast, chemigation, soil broadcast, soil incorporated NS apps at 1.9 lb ai/A

Sesame Broadcast, soil band, soil broadcast 1 2 

### app at 1.3 lb ai/A Sorghum Soil broadcast, soil treatment 1 2 

### app at 1.7 lb ai/A Broadcast, band, chemigation, impregnated dry bulk fertilizer, low volume spray (concentrate) spray, soil band, soil incorporated 1 3 

### app at 1.6 lb ai/A

Soil treatment (surface) 1 3 

### app at 1.3 lb ai/A Sorghum (silage) Band, broadcast, impregnated dry bulk fertilizer, low volume spray (concentrate), soil band, soil

treatment, spray 1 3 

### app at 1.6 lb ai/A +++

Direct spray NS apps at 1.1 lb ai/A Soil incorporated, soil treatment 2 3 

### apps at 1.3 lb ai/A

### 70 (surface) Sorghum (unspecified) Broadcast, chemigation, soil broadcast, soil incorporated, soil treatment, soil treatment (surface) 1 app at 1.6 lb ai/A

Soybeans (unspecified) Broadcast, soil broadcast, soil incorporated 1 3 

### app at 1.6 lb ai/A

Chemigation, soil band, soil broadcast, soil incorporated, soil treatment (surface) 1 2,3 

### app at 2.5 lb ai/A

Direct spray, 1-2 2 

### app at 1.3 lb ai/A Soybeans (edible, edamame) Broadcast, chemigation, soil broadcast, soil incorporated, soil treatment (surface) 1 3 

### app at 1.9 lb ai/A

Spinach Broadcast, chemigation 2 

### , soil

broadcast 2 

### 1 app at 0.95 lb ai/A

Soil band 1 2 

### app at 0.64 lb ai/A Squash (winter, Hubbard) Broadcast, chemigation, soil

broadcast 1 2 

### app at 1.3 lb ai/A

Sugar beet Broadcast, chemigation, soil broadcast, soil incorporated 2 2 

### app at 1.9 lb ai/A

Sunflower Broadcast, chemigation, soil broadcast, soil incorporated NS apps at 1.9 lb ai/A

Sweet Potato Broadcast, soil broadcast 1 app at 1.3 lb ai/A Tomato Direct spray, soil band, soil broadcast, soil incorporated, soil treatment (surface) 1 3 

### app at 1.9 lb ai/A

Turnip (greens), turnip (root) Broadcast, chemigation, soil broadcast, soil incorporated 1 2 

### app at 1.3 lb ai/A

Soil Band 1 2 

### app at 0.64 lb ai/A
NS – Not Specified on the label NDC – No Dosage Conversion

1 

### Minimum application interval was not specified unle ss otherwise noted.

2 

### Number of applications assumed, based on the crop cycle maximum application rate.

3 

### Number of applications assumed, based on the yearly maximum application rate.

### 71 

## Appendix B: Uses and Rate Table fo r Special Local Needs (SLN) Labels for

Metolachlor/S-Metolachlor

Registration # Crop Maximum Application Rate (lb ai/A) Single (App.

Method) Annual/Seasonal

METOLACHLOR (P C CODE 108801)

LA110008 Corn (unspecified), Cotton (unspecified), Soybeans (unspecified) 2.1 (B,SB) 4 (Annual)

MS120002 Corn (unspecified), Cotton (unspecified), Soybeans (unspecified) 2.1 (B,SB) 4 (Annual)

S-METOLACHLOR (PC CODE 108800)
AL100003 Sesame 1.3 (B,BA,SB) 1.3 (Seasonal) AR030011 Spinach 0.64 (SB) NS

AR08 0 0 1 7 Corn (unspecified), Cotton (unspecified), Soybeans (unspecified) 1.6 (B,SB) 2.5 (Annual)

ARll0 0 0 4 Sweet Potato 1.3 (B,SB) NS

AR1300 1 3 Soybeans (unspecified) , Corn (Unspecified) 1.3 (B, SB) 2.5 (Seasonal)

AZI200 0 6 Spinach 0.64 (C,B,SB) NS

CA 0 100 22 Bell Peppers, Pepper (Chili Type) 1.6 (D, SB) 1.6 (Seasonal)

CA030004 Tomato 1.6 (D,BA,SI,S) NS

CA060019 Chard (Swiss) 1.3 (B,C,SB) NS

CA080006 Spinach 0.95 (B, SB,C) NS

CA080017 Onion 1.3 (SB, BA, B, C) 2.5

CA080019 Celery 1.9 (B, C, SB, SI) 1.3 (D) 1.9 (Seasonal) 1.9 (Seasonal)

CAI00004 Root Vegetables (except sugar beet), Tuberous and Corm Vegetables 1.3 (SB, SI, S) 1.3 (Seasonal)

C0030008 Spinach 0.64 (SB, BA) NS

C0990002 Onion 1.3 (SB, BA) 2.5

D E030005 Spinach 0.64 (SB) NS

DE040 0 0 4 Asparagus 1.9 (B, C, BA, SB) NS

DEI I OOO I Melons, water 1.2 (C, BA, SB) 1.2 (Seasonal)

FL110007 Root Vegetables (except sugar beet), Tuberous and Corm Vegetables 1.3 (SB, B, C) 1.3 (Seasonal)

GA0900 0 1 Onion, Onions (Green) 1.3 (SB, B) 2.5 (Annual) 1.3 (Seasonal) Broccoli 1.3 (SB, B) NS

### 72 1.2 (BA) Cabbage (Chinese),

Cauliflower 1.3 (B, BA, SB) 1.2 (BA) 0.95 (SB, B) NS

Bell Peppers 0.95 (B, SB) 0.95 (Seasonal)

ID020001 Alfalfa 3.2 (C, SB) NS

ID9900 1 6 Onion 1.3 (SB, B) 2.5 (Annual) IL070005 Soybean 1.3 (SB, B) 2.5 (Annual) IL100003 Cabbage 1.3 (B, SB) 1.3 (Seasonal) IL14000l Horseradish 1.2 (C, SB) 1.2 (Seasonal)

IN130003 Onion 1.3 (SB, BA, B, C) 2.5 (Annual) Cabbage 1.3 (B, SB, C) 1.3 (Seasonal) Beets (root), Beets (unspecified) 1.2 (B, C, SB, SI) 1.3 (Seasonal)

Ornamental Herbaceous

Plants 1.2 (B, C, SB, BA) 1.3 (Seasonal)

Coriander, Spinach, 0.95 (B, C, SB) 0.95 (Seasonal) Squash (winter)( hubbard) 1.3 (B, C, SB) 1.3 (Seasonal) Carrot (including tops) 1.9 (B, C, SB) 1.9 (Seasonal) Pepper 1.3 (SB) 0.95 (B, C) 1.3 (Seasonal) 0.95 (Seasonal) Cucumber, Leafy Vegetables 1.3 (B, C, SB) 1.3 (Seasonal) Blackberry, Loganberry, Raspberry (black, red) 1.9 (SB, BA) 1.9 (Seasonal)

Bulb Vegetables 1.3 (B, C, BA, SB) 1.3 (Seasonal) Currant, Elderberry, Gooseberry, Huckleberry, Blueberry 1.3 (BA) 1.3 (Seasonal)

Melons, Radish 1.2 (B, C, BA, SB) 1.2 (Seasonal) Okra 1.9 (D, BA) 1.9 (Seasonal) Turnip (Root), Turnip (Greens) 1.3 (B, C, SB, SI) 1.3 (Seasonal)

KS100001 Sesame 1.3 (B,BA,SB) 1.3 (Seasonal)

L A 1 30008 Soybeans (unspecified), Corn (unspecified) 1.3 (B, SB) 2.5 (Seasonal)

ME140002 Bell Peppers 1.6 (SB) 0.95 (B) 1.6 (Seasonal) 0.95 (Seasonal) Spinach 0.95 (B, SB) NS

Asparagus 1.9 (B, C, BA, SB) NS Cabbage, Onion (Green) 1.3 (B, SB) NS Onion 1.3 (B, C, SB, SI, S) 2.5 (Seasonal) Pumpkin 1.3 (C, B, SB) 1.3 Chard (swiss) 0.95 (B, C, BA, SB) 1.33 (Annual) Beets (Greens) 0.64 (B, C, BA, SB) 0.64 (Seasonal)

### 73 Carrot (Including Tops) 1.9 (B, C, SB) 1.9 (Seasonal)

MI110004 Onion 1.3 (SB, BA, B, C) 2.5 (Annual) Celery 1.9 (B, C, SB, SI) 1.9 (Seasonal) Cabbage 1.3 (B, SB, C) 1.3 (Seasonal) Squash (winter)( hubbard) 1.3 (B, C, SB) 1.3 (Seasonal) Carrot (including tops) 1.9 (B, SB, C) 1.9 (Seasonal) Blueberry 1.3 (BA) 1.3 (Seasonal) Spinach 0.95 (B, SB, C) 0.95 (Seasonal) Pepper 1.3 (SB) 0.95 (B, C) 1.3 (Seasonal) 0.95 (Seasonal) Cucumber 1.3 (B, C, SB) 1.3 (Seasonal) Blackberry, Loganberry 1.9 (SB, BA) 1.9 (Seasonal) Bulb Vegetables 1.3 (B, C, BA, SB) 1.3 (Seasonal) Currant, Elderberry, Gooseberry, Huckleberry 1.3 (BA) 1.3 (Seasonal)

Melons 1.2 (B, C, BA, SB) 1.2 (Seasonal) Okra 1.9 (D, BA, C) 1.9 (Seasonal) Raspberry (black,red) 1.9 (SB, BA) 1.9 (Seasonal) Leafy Vegetables, Broccoli, Brussels sprouts, Cabbage (Chinese), Cauliflower 1.3 (B, C, SB) 1.3 (Seasonal)

Turnip (Root) 1.3 (B, C, SB, SI) 1.3 (Seasonal) Asparagus 1.9 (BA, B, C, SB) 1.9 (Seasonal) Chard (Swiss) 0.95 (B, BA, SB, C) 0.95 (Seasonal) Radish/Daikon (Chinese), Parsnip, Rutabaga 1.3 (B, C, SB, SI) 1.3 (Seasonal)

Eggplants 1.3 (SB, B) 1.3 (Seasonal) MN000001 Onion 1.3 (SB, B, C) 2.5 (Annual)

MN0 4 0002 Sugar Beet 1.9 (SI) 3.8 (Seasonal) MN080006 Squash (winte r)(hubbard) 1.3 (B, C, SB) 1.3 (Seasonal) MN090004 Crops Grown for oil 1.3 (B, SB, SI) 1.3 (Seasonal) MN12000l Carrot (including tops) 1.9 (B, C, SB) 1.9 (Seasonal)

MN 1 30001 Beans (Dried-Type) 1.3 (B, C, S) 1.9 (Annual)

MO040002 Spinach 0.64 (SB) NS MS060005 Sweet Potato 1.3 (B,SB) NS

MS080005 Corn (unspecified)

Cotton (unspecified)

Soybeans (unspecified) 1.6 (B,SB) 2.5 (Annual)

MS 120001 Soybeans (unspecified) 1.3 (B, SB) 2.5 (Seasonal) NC060002 Sweet Potato 1.3 (B,SB) NS

NCII0005 Bell Peppers 0.95 (SB) 0.95 (Seasonal)

ND040001 Soybean 1.3 (SB, B) 2.5 (Annual)

N D I30003 Beans (Dried-Type) 1.3 (B, C, S) 1.9 (Annual)

### 74 NJIIOOI2 Onion 1.3 (BA, SB, B) 2.5 (Annual) 1.3 (Seasonal) Onions (Greens) 1.3 (BA, C) 1.3 (Seasonal) Cabbage 1.3 (BA, SB, C) NS Carrot (including tops), Asparagus 1.9 (B, C, SB, BA) 1.9 (Seasonal)

Blueberry 1.3 (BA) 1.3 (Seasonal) Pepper 1.3 (SB, BA) 1.3 (Seasonal) Chard (Swiss) 0.95 (B, BA, SB, C) 0.95 (Seasonal) Spinach 0.64 (SB) 0.64 (Annual) Leek 1.3 (B, C, BA, SB) 1.3 (Seasonal)

NM000001 Onion 1.3 (SB,B) 2.5

NM990002 Bell Peppers 0.95 (SB) 0.95 (Seasonal) Pepper (Chili Type), Bell Peppers 1.3 (D) 1.3 (Seasonal)

NV9900 0 6 Alfalfa 3.2 (C, SB) NS

NY050001 Bell Peppers 1.6 (SB) 0.95 (B) 1.6 (Seasonal) 0.95 (Seasonal) Asparagus 1.9 (B, C, BA, SB) NS Cabbage 1.3 (B, SB) NS Onion (Green) 1.3 (B, C, SB, BA) NS Onion 1.3 (B, C, SB, BA) 1.3 (B, C, SB, SI, S) NS 2.55 (Seasonal) Pumpkin, Squash (Winter) (Hubbard) 1.3 (C, B, SB) 1.3 (Seasonal)

Chard (swiss) 0.95 (C, B, BA, SB) 1.33 (Annual) Beets (Greens) 0.64 (B, C, BA, SB) 0.64 (Seasonal) Carrot (Including Tops) 1.9 (B, C, SB, BA) 1.9 (Seasonal) Spinach 0.64 (BA) 0.64 (Seasonal)

NY110004 Broccoli 1.3 (B, SB) NS Blueberry 1.3 (BA) 1.3 (Seasonal) Cucumber, Leafy Brassica

Greens 1.3 (B, C, SB) 1.3 (Seasonal)

Caneberry (blackberry and raspberry) 1.9 (BA) 1.9 (Seasonal)

Melon Subgroup 1.2 (B, C, BA, SB) 1.2 (Seasonal) Garlic 1.3 (B, C, BA, SB) NS

OH11000 2 Onion, Bulb Vegetables 1.3 (SB, BA, B,C) 2.5 (Annual) Cabbage, Squash (winter)(hubbard) 1.3 (B, SB, C) 1.3 (Seasonal)

Carrot (including tops) 1.9 (B, C, SB) 1.9 (Seasonal) Spinach 0.95 (B, SB, C) 0.95 (Seasonal) Pepper 1.3 (SB) 0.95 (B, C) 1.3 (Seasonal) 0.95 (Seasonal) Cucumber, Leafy Vegetables 1.3 (B, C, SB) 1.3 (Seasonal)

### 75 Blackberry, Loganberry, Raspberry (black,red) 1.9 (SB, BA) 1.9 (Seasonal)

Currant, Elderberry, Gooseberry, Huckleberry, Blueberry 1.3 (BA) 1.3 (Seasonal)

Melons 1.2 (B, C, BA, SB) 1.2 (Seasonal) Okra 1.9 (D, BA) 1.9 (Seasonal) Turnip (Root), Turnip (Greens), Beets (Greens) 1.3 (B, C, SB, SI) 1.3 (Seasonal)

Radish 1.2 (B, C, SB, SI) 1.2 (Seasonal)

OK020003 Pepper 0.95 (SB) NS (C) NS

NS

OK030002 Spinach 0.64 (SB) NS

OKI00002 Sesame 1.3 (B, BA, SB) 1.3 (Seasonal) OK110001 Sweet Potato 1.3 (B,SB) NS

OR040 0 1 0 Radish 1.3 (SB) 1.3 (Annual)

OR060 0 1 2 Carrot (Including Tops) 1.9 (B, C, SB, BA) 1.9 (Seasonal) Beets (Greens), Parsnip, Radish/Daikon (Chinese), Rutabaga, Turnip (Greens), Turnip (Root) 0.64 (B, C, BA, SB) 0.64 (Seasonal)

OR1100 0 5 Blueberry 1.3 (BA) 1.3 (Seasonal) Raspberry (black,red) 1.9 (BA) 1.9 (Seasonal)

PA0800 0 2 Spinach 0.95 (B, SB) NS Onion, Cabbage 1.3 (SB, BA,B) 2.5 (Annual) 1.3 (Seasonal) Bell Peppers 0.95 (B, SB) 0.95 (Seasonal)

SC070002 Spinach 0.64 (B, SB) NS

TN1 10004 Leafy Vegetables 1.3 (B, C, SB)

0.64 (D) 1.3 (Seasonal)

0.64 (Seasonal)

TN1 3 0004 Soybeans (unspecified), Corn (unspecified) 1.3 (B, SB) 2.5 (Seasonal)

TX040011 Cotton (Unspecified) 1.3 (B, C, SB) NS

TX 0 7 0003 Onion 1.3 (SB, BA, B) 2.5 (Annual) Onions (Greens) 1.3 (BA) 1.3 (Seasonal) Cabbage, Beets (Greens) 1.3 (B, SB) 1.3 (Seasonal) Pepper 1.3 (SB) 0.95 (B) 1.3 (Seasonal) 0.95 (Seasonal) Sweet Potato 0.95 (B, SB) 0.95 (Seasonal)

TX080006 Pumpkin 1.3 (B, SB) 1.3 (Seasonal) Chard (Swiss) 0.95 (B, BA, SB) 0.95 (Seasonal)

TX1 0 0008 Sesame 1.3 (B, BA, SB) 1.3 (Seasonal)

TX100013 Spinach 0.64 (B, SB) NS

TX1 0 0014 Beans (Succulent, lima) 1.9 (B, SB, SI) 1.9 (Annual)

### 76 VA030003 Spinach 0.64 (B, SB, BA) NS VA110006 Melons, water 1.2 (C, BA, SB) 1.2 (Seasonal) VA990001 Onion 1.3 (SB,B) 2.5 (Annual)

VA990002 Cabbage 1.3 (B, SB) 1.3 (Seasonal) Bell Peppers 1.3 (D, C, S) 1.3 (Seasonal)

WA120001 Chard (swiss) 0.95 (B, SB, BA) 1.33 (Annual) Beets (Greens) 0.64 (B, SB) 0.64 (Annual)

WA120002 Blueberry 1.3 (BA) 1.3 (Seasonal) Blackberry, Raspberry (black,red) 1.9 (BA) 1.9 (Seasonal)

WI130001 Onion 1.3 (SB, BA, B,C) 2.5 (Annual) 1.3 (Seasonal) Onions (Greens) 1.3 (BA, C) 1.3 (Seasonal) Celery 1.9 (B, C, SB, SI) 1.9 (Seasonal) Cabbage 1.3 (B, SB, C) 1.3 (Seasonal) Carrot (including tops) 1.9 (B, C, SB) 1.9 (Seasonal) Spinach 0.95 (B, SB, C) 0.95 (Seasonal) Pepper 1.3 (SB) 0.95 (B, C) 1.3 (Seasonal) 0.95 (Seasonal) Cucumber 1.3 (B, C, SB) 1.3 (Seasonal) Turnip (Root), Turnip (Greens), Beets (Greens), Radish/Daikon (Chinese), Parsnip, Rutabaga 1.3 (B, C, SB, SI) 1.3 (Seasonal)

Chard (Swiss) 0.95 (B, BA, SB, C) 0.95 (Seasonal) Broccoli, Brussels sprouts, Cabbage (Chinese),

Cauliflower 1.3 (B, C, SB,) 1.3 (Seasonal)

Eggplants 1.3 (SB, B) 1.3 (Seasonal) Leek 1.3 (B, C, BA, SB) 1.3 (Seasonal) WY110001 Radish 1.3 (SB) 1.3 (Annual) NS: Not Specified Application Methods:

B: Broadcast SB: Soil Broadcast BA: Band Treatment C: Chemigation SI: Soil Incorporated S: Soil Treatm ent (Surface) D: Directed Spray

### 77 

## Appendix C: Previous Actions a nd Assessed Uses for Metolachlor/SMetolachlor

Use Site Max. Application Rate (lb ai/A) Number of Applications (Application

Interval in Days) Action/DP

Barcode/Date Comments

Single (App Method) Seasonal/

Annual

Metolachlor (PC Code 108801)

N/A N/A N/A N/A Revised TRED DWA

D238805 +9 more

5/22/2002

Tomatoes 1.5-3.0 NS NS Section 18 Emergency Exemption Pennsylvania

D234833

4/22/1997 Spinach 0.75-1.0 (G,A) 0.75-1.0 1 Section 18 Emergency Exemption Virginia

D221250

1/17/1996 Not likely to affect non-listed or listed animal populations. Agency LOCs exceeded for terrestrial and aquatic plants.

Spinach 1 (G) 2 (I) 3 2 (NS) Section 18 Emergency Exemption

Texas

8/2/1995 Agency LOCs exceeded for terrestrial and aquatic plants.

Spinach 1.0 (G) 1 1 Section 18 Emergency Exemption New Jersey

D213744

4/20/1995 Agency LOCs exceeded for terrestrial and aquatic plants.

Spinach 1.0 (G) 1 1 Section 18 Emergency Exemption

Louisiana

D208252

1/10/1995 Spinach 1.0 (G) 1 1 Section 18 Emergency Exemption

Arkansas

D208746

1/10/1995 Spinach 1.0 (G) 1 1 Section 18 Emergency Exemption Maryland

8/19/1994 Spinach 1.0 (G) 1 1 Section 18 Emergency Exemption

Oklahoma

D198582

2/15/1994

All Uses N/A N/A N/A RED D185152, D172022

6/30/1993 Ecological Effects Branch

Review

### 78 All Uses N/A N/A N/A RED D185152, D172022

3/1/1993 Environmental Fate and

Ground Water Branch Review

Cabbage 2 (G) 2 1 Section 18 Emergency Exemption

New York

5/31/1988 Cabbage 2 (G) 2 1 Section 18 Emergency Exemption

Wisconsin

3/10/1988 Dry Bulb

Onions 2 (G) 4 2 (NS) Section 18 Emergency Exemption

Wisconsin

1/9/1987 Cabbage 2 (G) 2 1 Section 18 Emergency Exemption

New York

2/24/1987 Proposed use will have minimal

adverse effects on listed species.

Dry Bulb

Onions 2 (G) 4 2 (NS) Section 18 Emergency Exemption Michigan

1/9/1987 Proposed use will have minimal

adverse effects on listed species.

Cole crops (cabbage, broccoli, collards) 1.5-2.0 pints/A NS NS Section 18 Emergency Exemption

Florida

10/2/1981 Sunflower,

Flax 2.5-3 NS NS Section 3

New Use

10/27/1980 Use Site: potatoes, sorghum, right of ways, peanuts, soybeans, field corn
S- Metolachlor (PC Code 108800) Cilantro,

Garden

beet leaves 0.96 (G)

1.27 (G) 0.96

1.27 1

1 Section 3

New minor uses

D392602

1/4/2012 LOC exceedances for birds and freshwater aquatic invertebrates from chronic exposure, terrestrial and aquatic plants

and mammals from chronic

exposure. Cilantro,

Garden

beet leaves 0.96 (G)

1.27 (G) 0.96

1.27 1

1 DWA

D392449

11/11/2011

Lettuce 0.95 (G) (per crop) 0.95 1 Section 18 Emergency Exemption Michigan

D390436

6/22/2011

Various IR4 Uses 3.81 (G) 1 3.81 1 Section 3

New minor uses

D370759

6/23/2010 Uses include: sesame, melon, bushberry, caneberry, sorghum, leafy brassica, turnip greens, carrot,, cucumber, okra, dry bulb onions and green onion.

LOC exceedances for chronic risk to freshwater fish,

invertebrates and acute risk to

### 79 vascular and nonvascular aquatic plants for all uses.

Various IR4 Uses (max rate is caneberry) 3.81 (G) 1 3.81 1 DWA

D368735

4/22/2010

Sesame 1.27 (G,A) 1.27 1 Section 18 Emergency Exemption Oklahoma, Texas D367230, D367228

9/15/2009 Ecological risk are to terrestrial and aquatic plants.

Leafy Greens,

Herbs 1.27 (G) 1.27 1 Section 18 Emergency Exemption

Ohio

D329114

5/31/2006 Pumpkin,

Winter Squash 1.27 (G) 1.27 1 Section 3

New minor uses D324973, D327861

5/31/2006 Non-listed and listed terrestrial plant LOCs are exceeded.

Pumpkin,

Winter Squash 1.27 (G) 1.27 1 DWA

D324967

3/20/2006 Assessment conclusions drawn

from DWA for corn. 45845

Various IR4 Uses 2.5 (A) 1 2.5 1 DWA

D296726

6/16/2004 IR-4 Uses Include: fruiting vegetables, green and dry bulb onions, root vegetables (except sugarbeets), tuberous and corn vegetables, head and stem brassica, leaf petioles, Spinach.

Assessment conclusions drawn

from 2002 tolerance reassessment (TRED; D248805). 3401

Red Beets 0.66

0.33 0.66

0.66 1

2 Section 18 Emergency Exemption

New York

D297472

1/23/2004 Exceedances for both acute

listed and non-listed LOC at a single and multiple (2) applications.

23834

Sweet

Potatoes 1.27 1.27 1 Section 18 Emergency Exemption

Louisiana

D282660

5/15/2002 Acute and chronic exceedances for terrestrial plants. 4663-4

1 Highest proposed use rate.

*Value is assumed. N/A= Not applicable, NS = Not speci fied, DWA = Drinking Water Assessment, EFGWB = Environmental Fate and

Ground Water Branch G = ground, A = aerial, I = Irrigation80Appendix D: Summary of Endpoints from Metolachlor/S-Metolachlor Toxicity StudiesSummary of Endpoints from ToxicityStudies with Metolachlor (CGA-24705)Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationAvian acute oral:single dose, 8-dayobservation (insteadof usual 14-dayobservation)Metolachlortechnical(NS)Mallard duck(Anas platyrhynchos)LD50(95% C.I.) = 4640 (3000-7200) mg/kg-bw (nom)NOAEC : Not specifiedPractically non-toxicMRID 00015547Supplemental(due to guidelinedeviations)Avian acute oral:single dose, 14-dayobservationMetolachlortechnical(NS)Mallard duck(Anas platyrhynchos)LD50> 2510 mg/kg-bw (nom)NOAEC : Not specified(no treatment-related effects)Practically non-toxicMRID 00062465AcceptableAvian acute oral Metolachlor Passerine species No data NAAvian sub-acutedietary: 5-dayexposure; 3-daypost-exposureobservationMetolachlortechnical(NS)Mallard duck(Anas platyrhynchos)LC50> 10,000 mg/kg-diet (nom)NOAEC: Not specified(no mortality; sublethal effects: decreased weight gain at≥4640mg/kg-diet; decreased feed consumption at 10,000 mg/kg-diet)Practically non-toxicMRID 00016425AcceptableMetolachlortechnical(NS)Bobwhite quail(Colinus virginianus)LC50> 10,000 mg/kg-diet (nom)NOAEC: Not specified(10% [1/10] mortality at 10,000 mg/kg-diet; sublethal effects:wing droop, lethargy, no weight gain, and greatly decreased feedconsumption at 10,000 mg/kg-diet)Practically non-toxicMRID 00014626AcceptableAvian reproduction:~20 weeks (chronic)Metolachlortechnical(97.2)Bobwhite quail(Colinus virginianus)NOAEC = 403 mg a.i./kg-diet (mm)LOAEC = 1010 mg a.i./kg-diet (mm)(based on increase in cracked eggs)MRID 46508901AcceptableAvian reproduction:20 weeks (chronic)Metolachlortechnical(97.3)Mallard duck(Anas platyrhynchos)NOAEC = 800 mg a.i./kg-diet (nom)LOAEC > 800 mg a.i./kg-diet (nom)(no treatment-related effects)MRID 44015602AcceptableAvian reproduction:22 weeks (chronic)Metolachlortechnical(97)Mallard duck(Anas platyrhynchos)NOAEC = 10 mg/kg-diet (nom)LOAEC = 300 mg/kg-diet (nom)(based on adult feed consumption and body weight)MRID 00162292Supplemental81Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationMammalian acuteoral, limit: singledose; 7-dayobservation (insteadof usual 14-dayobservation)Metolachlor(NS)Rat(Rattus norvegicus)LD50(95% C.I.) = 2780 (2180-3545) mg/kg-bw(20,30, 50, and 100% mortality at 1670, 2150, 2780, and 4640mg/kg-bw ; sublethal effects : dose-dependent increase insedation, dyspnea, exophthalmos, curved position, trismus,tonic-clonic muscle spasms, andruffled fur ; surviving animalsrecovered within 3 to 5 days)Practically non-toxicMRID 00015523AcceptableMammalian acuteinhalationMetolachlor Rat(Rattus norvegicus)LC50> 1.75 mg/L MRID 00015535Mammalianreproduction(chronic)Metolachlor Rat(Rattus norvegicus)NOAEC = 300 mg a.i./kg-diet(based on reduced pup weights in F1 and F2 litters)MRID 00080897AcceptableAcute contact withadult honey bees:single dose, 48-hourobservationMetolachlor(97)Adult honey bee(Apis mellifera)LD50> 110 μg a.i./bee (nom)NOAEL = 110 μg a.i./bee (nom)(no control mortality ; 0-5% mortality across 4 treatmentconcentrations)Practically non-toxicMRID 44718401AcceptableAcute oral with adulthoney bees: singledose, 48-hourobservationMetolachlor(97)Adult honey bee(Apis mellifera)LD50> 110 μg a.i./bee (nom)NOAEL = 110 μg a.i./bee (nom)(no control mortality ; 0-7.5% mortality across 4 treatmentconcentrations)Practically non-toxicMRID 44718401AcceptableAcute oral withhoney bee larvaeNA Larval honey bee No data NAChronic oral withhoney bee adultsNA Adult honey bee No data NAChronic oral withhoney bee larvaeNA Larval honey bee No data NATerrestrial plantseedling emergence:21 daysMetolachlortechnical(97.3)Most sensitivemonocot: RyegrassEC25(95% C.I.) = 0.02 (0.017-0.033) lb a.i./ANOAEC = 0.0031 lb a.i./A(based on dry weight, height)MRID 43487107AcceptableMost sensitive dicot:LettuceLettuce: EC25(95% C.I.) = 0.09 (0.012-0.62) b a.i./ANOAEC = 0.012 lb a.i./A(based on dry weight)82Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationNote: Lettuce also had an EC25of 0.09 lb a.i./A for dry weight,but the associated NOAEC of0.049 lb a.i./A was slightlyhigher.Terrestrial plantvegetative vigor:21 daysMetolachlortechnical(97.3)Most sensitivemonocot: RyegrassEC25= 0.016 lb a.i./ANOAEC = 0.0031 lb a.i./A(based on dry weight)MRID 43487108AcceptableMost sensitive dicot:CucumberEC25(95% C.I.) = 0.030 (0.020-0.046) lb a.i./ANOAEC = 0.025 lb a.i./A(based on dry weight)Freshwater fishacute: 96 hoursMetolachlortechnical(NS)Rainbow trout(Salmo gairdneri)LC50(95% C.I.) = 3.80 (3.37-4.27) mg/L (nom)NOAEC: Not specified(no mortality at≤2.8 mg/L; mortality at≥4.1 mg/L)Moderately toxicMRID 00018722AcceptableFreshwater fishacute: 96 hoursTechnicalmetolachlor(NS)Crucian carp(Carassius carassius)LC50(95% C.I.) = 4.9 (3.6-6.8) mg/L (nom)(sublethal effects: hypersensitivity, loss of equilibrium, andapathy at≥2.1 mg/L)Moderately toxicMRID 00015534Supplemental(due to nonrecommended testspecies and lowtemperature)Freshwater fishacute: 96 hoursTechnicalmetolachlor(NS)Channel catfish(Ictalurus punctatus)LC50(95% C.I.) = 4.9 (3.6-6.8) mg/L (nom)(sublethal effects: hypersensitivity, loss of equilibrium, andapathy at≥2.1 mg/L)Moderately toxicMRID 00015534AcceptableFreshwater fishacute: 96 hoursTechnicalmetolachlor(NS)Guppy(Lebistes reticulatus)LC50(95% C.I.) = 8.6 (7.4-10.5) mg/L (nom)(sublethal effects: hypersensitivity, loss of equilibrium, andapathy at≥6.5 mg/L)Moderately toxicMRID 00015534Supplemental(due to nonrecommended testspecies)Freshwater fishacute: 96 hoursMetolachlortechnical(NS)Bluegill sunfish(Lepomis macrochirus)LC50(95% C.I.) = 10.3 (9.5-11.1) mg/L (nom)NOAEC = 6.0 mg/L (nom)LOAEC = 8.8 mg /L (nom)Slightly toxicMRID 00018723Acceptable83Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationFreshwater fishacute: 96 hoursTechnicalmetolachlor(NS)Bluegill sunfish(Lepomismacrochirus)LC50= 15 mg/L (nom)(no mortality at≤10 mg/L; sublethal effects: hypersensitivity,loss of equilibrium, and apathy at concentration where mortalityoccurred)Slightly toxicMRID 00015534Supplemental(due to lowtemperature)Freshwater fish earlylife stageMetolachlor Freshwater species No data NAEstuarine/marinefish acute: 96 hours,flow throughMetolachlortechnical(97.3)Sheepshead Minnow(Cyprinodonvariegatus)LC50(95% C.I.) = 9.8 (8.5-11.5) mg a.i./L (mm)NOAEC = 3.6 mg a.i./L (mm)LOAEC = 6.2 mg a.i./L (mm)(sublethal effects: lethargyand loss of equilibrium wereobserved among all surviving fish at 11 mg/L and to one fish at6.2 mg/L)Moderately toxicMRID 43487101AcceptableEstuarine/marinefish acute: 96 hours,flow throughMetolachlortechnical(97)Sheepshead Minnow(Cyprinodonvariegatus)LC50(95% C.I.) = 7.9 (4.4-∞) mg/L (mm)NOAEC: Not specified(no mortality at≤4.4 mg/L; 70% mortality at 9.4 mg/L)Moderately toxicMRID 43044602Supplemental(due to guidelinedeviations)Estuarine/marinefish early life stage(chronic): 26 days,flow throughMetolachlortechnical(97)Sheepshead Minnow(Cyprinodonvariegatus)NOAEC = 1.0 mg/L (mm)LOAEC = 2.2 mg/L (mm)(NOAEC based on most sensitive endpoint of reduced length;survival and hatch also affected)MRID 43044602Supplemental(due to guidelinedeviations)Freshwaterinvertebrate acute:48 hours, staticMetolachlor(Not reported)Water flea(Ceriodaphnia dubia)EC50(95% C.I.) = 1.1 (0.9-1.4) mg/LModerately toxicE067777Quantitative(Fosteret al., 1998)Freshwaterinvertebrate acute:48 hoursMetolachlortechnical(NS)Water flea(Daphnia magna)EC50(95% C.I.) = 25.1 (21.6-29.2) mg a.i./LNOAEC = 5.6 mg a.i./LLOAEC = 10 mg a.i./L(NOAEC based no mortality at 5.6 mg/L)Slightly toxicMRID 00015546AcceptableFreshwaterinvertebrate lifeMetolachlor(Not reported)Water flea(Daphnia magna)NOAEC = 0.001 mg/L (nom)LOAEC = 0.01 mg/L (nom)(based on number of young per female)E083887Quantitative(Liuet al,2006)84Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationcycle: 21 days, staticrenewalFreshwaterinvertebrate lifecycle: 21 days, flowthrough (chronic)Metolachlortechnical(97.2)Water flea(Daphnia magna)NOAEC = 4.9 mg a.i./L (mm)LOAEC = 9.4 mg a.i./L (mm)(NOAEC based reductions in growth [length] and reproduction)MRID 46322101AcceptableFreshwaterinvertebrate lifecycle: 21 days, flowthrough (chronic)Metolachlortechnical(97)Water flea(Daphnia magna)NOAEC = 3.2 mg a.i./L (m)LOAEC = 6.9 mg a.i./L (m)(NOAEC based reductions in growth and reproduction)Note: Due to variability in the measured concentrations, theendpoints are based on the lowest measured concentration ateach treatment level.MRID 43802601Supplemental(due to uncertainexposureconcentrations lackof raw growth data)Estuarine/marineinvertebrate acute:96 hours, flowthroughMetolachlortechnical(97.3)Mysid shrimp(Mysidopsis bahia)EC50(95% C.I.) = 4.95 (4.21-5.94) mg a.i./L (mm)Probit slope (95% C.I.) = 6.1 (3.5-8.6)NOAEC = 2.3 mg a.i./L (mm)LOAEC = 4.0 mg a.i./L (mm)(NOAEC based on no mortality at≤2.3 mg/L; survivingdaphnids at 4.0 and 7.1 mg/L exhibited dark pigmentation andlethargy)Moderately toxicMRID 43487103AcceptableEstuarine/marinemollusc acute: 96hours, flow through,shell depositionMetolachlortechnical(97.3)Eastern oyster(Crassostreavirginica)EC50(95% C.I.) = 1.6 (1.4-1.9) mg a.i./L (mm)NOAEC = 0.71 mg a.i./L (mm)LOAEC = 1.1 mg a.i./L (mm)(sublethal effects: reduction in feeding and fecal andpseudofecal production wereobserved at all observationintervals at the highest treatment level, 4.5 mg/L)Moderately toxicMRID 43487102AcceptableEstuarine/marineinvertebrate lifecycleMetolachlorEstuarine/marinespeciesNo data NABenthic freshwaterinvertebrateMetolachlorFreshwater species No data NA85Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationBenthicestuarine/marineinvertebrateMetolachlorEstuarine/marinespeciesNo data NAAquatic vascularplant: 14 days, staticMetolachlortechnical(97.3)Duckweed(Lemna gibba)EC50(95% C.I.) = 0.048 (0.043-0.056) mg a.i./L (im)NOAEC = 0.0084 mg a.i./L (im)LOAEC = 0.015 mg a.i./L (im)(based on frond number; sublethal effects: little root formation,smaller fronds, and chlorosis at0.058 mg/L, compared to thecontrol; slight chlorosis at 0.0084 to 0.030 mg/L; severalchlorotica fronds in control and at 0.0011 to 0.0042 mg/L)MRID 43487105AcceptableAquatic nonvascular plant:120 hours, staticMetolachlortechnical(97.3)Green alga(Selenastrumcapricornutum)EC50(95% C.I.) = 0.010 (0.006-0.020) mg a.i./L (mm)NOAEC = 0.0007 mg a.i./L (mm)LOAEC = 0.0014 mg a.i./L (mm)(based on cell density; bloated cells and cell fragments at≥0.0025 mg/L)MRID 43541301AcceptableAquatic nonvascular plant:120 hours, staticMetolachlortechnical(97.3)Marine diatom(Skeletonemacostatum)EC50(95% C.I.) = 0.061 (0.049-0.076) mg a.i./L (mm)NOAEC = 0.0017 mg a.i./L (mm)LOAEC = 0.0048 mg a.i./L (mm)(based on cell density; sublethal effects: cell fragments andbloated cells at≥0.15 mg/L; thin cell walls at≥0.56 mg/L)MRID 43487106AcceptableAquatic nonvascular plant:120 hours, staticMetolachlortechnical(97.3)Freshwater diatom(Navicula pelliculosa)EC50(95% C.I.) = 0.38 (0.27-0.56) mg a.i./L (mm)NOAEC = 0.0037 mg a.i./L (mm)LOAEC = 0.013 mg a.i./L (mm)(based on cell density; sublethal effects: bloated cells and cellfragments at≥0.13 mg/L)MRID 43541302AcceptableAquatic nonvascular plant:120 hours, staticMetolachlortechnical(97.3)Cyanobacterium(Anabaena flos-aquae)EC50(95% C.I.) = 1.2 (0.9-1.6) mg a.i./L (mm)NOAEC = 0.063 mg a.i./L (mm)LOAEC = 0.19 mg a.i./L (mm)(based on cell density; cell fragments at≥0.72 mg/L; bloatedcells at 6.8 mg/L)MRID 43487104AcceptableAbbreviations: C.I. = confidence interval; form. = formulation; im = initial measured; mm = mean measured; nom = nominal; NA =not applicable; NS = notspecified; TEP = typicalend-use product; TWA = time-weighted average86Summary of Endpoints from ToxicityStudies with S-Metolachlor (CGA-77102)Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationAvian acute oral:single dose, 14-dayobservationS-Metolachlortechnical(87.4)Mallard duck(Anas platyrhynchos)LD50> 2194 mg a.i./kg-bw (m)NOAEC = 2194 mg a.i./kg-bw (m)(no sublethal effects or treatment-related mortality)Practically non-toxicMRID 43928906AcceptableAvian acute oral:single dose, 14-dayobservationS-Metolachlortechnical(87.4)Bobwhite quail(Colinus virginianus)LD50> 2194 mg a.i./kg-bw (m)NOAEC = 874 mg a.i./kg-bw (m)LOAEC = 1390 mg a.i./kg-bw (m)(no mortality; body weight losses at≥1390 mg/kg-bw)Practically non-toxicMRID 43928907AcceptableAvian acute oral Metolachlor Passerine species No data NAAvian sub-acutedietary: 5-dayexposure; 3-daypost-exposureobservationS-Metolachlortechnical(87.4)Mallard duck(Anas platyrhynchos)LC50> 4912 mg/kg-diet (m)NOAEC = 1556 mg a.i./kg-diet (m)LOAEC = 2762 mg a.i./kg-diet (m)(20% [2/10] mortality at 874 mg/kg-diet; NOAEC based onslight reduction in body weight gain at≥2762 mg/kg-diet duringthe first 5 days of the test)Practically non-toxicMRID 43928909AcceptableS-Metolachlortechnical(87.4)Bobwhite quail(Colinus virginianus)LC50> 4912 mg/kg-diet (m)NOAEC = 2762 mg a.i./kg-diet (m)LOAEC = 4912 mg a.i./kg-diet (m)(no mortality; NOAEC based on slight reduction in body weightgain at 4912 mg/kg-diet during the first 5 days of the test)Practically non-toxicMRID 43928908AcceptableAvian reproduction:24 weeks (chronic)S-Metolachlor(98.6)Bobwhite quail(Colinus virginianus)NOAEC = 1000 mg a.i./kg-diet (nom)LOAEC > 1000 mg a.i./kg-diet (nom)(no effects)MRID 44995901AcceptableMammalian acuteoralS-Metolachlor Rat(Rattus norvegicus)Combined sexes LD50= 3267 mg/kg-bwMale LD50= 2577 mg/kg-bwFemale LD50= 2672 mg/kg-bwPractically n0n-toxicMRID4392891587Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationMammalian acuteinhalationS-Metolachlor Rat(Rattus norvegicus)LC50> 2.91 mg/L MRID 43928917Mammalianreproduction(chronic)S-Metolachlor Rat(Rattus norvegicus)No data NAAcute contact withadult honey bee:single dose, 72-hourobservationS-Metolachlor(98.5)Adult honey bee(Apis mellifera)LD50> 200 μg a.i./bee (nom)NOAEL = 200 μg a.i./bee (nom)(no control mortality ; 10% mortality at limit dose)Practically non-toxicMRID 44718402AcceptableAcute oral with adulthoney bee, limit:single dose, 72-hourobservationS-Metolachlor(98.5)Adult honey bee(Apis mellifera)LD50> 85 μg a.i./bee (nom)NOAEL = 85 μg a.i./bee (nom)(3% control mortality ; 3-10% mortality across 9 treatmentlevels)Practically non-toxicMRID 44718402AcceptableAcute oral withhoney bee larvaeNA Larval honey bee No data NAChronic oral withhoney bee adultsNA Adult honey bee No data NAChronic oral withhoney bee larvaeNA Larval honey bee No data NATerrestrial plantseedling emergence:21 daysS-Metolachlortechnical(97.6)Most sensitivemonocot: RyegrassEC25= 0.0048 lb a.i./ANOAEC = 0.0010 lb a.i./A(based on phytotoxicity)MRID 43928932Supplemental(due to only testing6 species instead ofthe required 10)Most sensitive dicot:LettuceEC25(95% C.I.) = 0.0057 (0.0011-0.0308) lb a.i./ANOAEC = 0.0003 lb a.i./A(based on dry weight)Terrestrial plantvegetative vigor:21 daysS-Metolachlortechnical(97.6)Most sensitivemonocot: RyegrassEC25(95% C.I.) = 0.021 (0.012-0.037) lb a.i./ANOAEC = 0.011 lb a.i./A(based on dry weight)MRID 43928933Supplemental(due to only testing6 species instead ofthe required 10)Most sensitive dicot:CucumberEC25(95% C.I.) = 0.27 (0.12-0.65) lb a.i./ANOAEC = 0.30 lb ai.i./AEC05= 0.01 lb a.i./ANote: Since the NOAEC > EC25, the EC05will be used forassessing risk to listed species.88Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassification(based on phytotoxicity)Freshwater fishacute: 96 hours,staticS-Metolachlortechnical(Not reported)Bluegill sunfish(Lepomis macrochirus)LC50(95% C.I.) = 3.2 (2.8-4.6) mg a.i./L (im)Probit slope (95% C.I.) = 14.8 (2.1-27.5)NOAEC = 1.5 mg a.i./L (im)LOAEC = 2.59 mg a.i./L (im)(NOAEC based on no mortalityor sublethal effects at≤1.5mg/L; swimming on surface at≥3.29 mg/L)Moderately toxicMRID 43928910AcceptableFreshwater fishacute: 96 hours,staticS-Metolachlor(97.6)Rainbow trout(Oncorhynchusmykiss)LC50(95% C.I.) = 11.9 (8.3-15) mg a.i./L (mm)NOAEC = 2.5 mg a.i./LLOAEC = 5.3 mg a.i./L (mm)(NOAEC based on sublethal effects including partial//completeloss of equilibrium, extended abdomen, lethargy, and residing onbottom at≥5.3 mg/L)Slightly toxicMRID 43928911AcceptableFreshwater fish earlylife stage: 30+ days,flow-throughS-Metolachlortechnical(98.6)Fathead minnow(Pimephales promelas)NOAEC = 0.030 mg a.i./L (mm)LOAEC = 0.056 mg a.i./L (mm)(based on most sensitive endpoint of dry weight; length alsoaffected)MRID 44995903AcceptableEstuarine/marinefish acute: 96 hours,static renewalS-Metolachlor(98.9)Sheepshead minnow(Cyprinodonvariegatus)LC50(95% C.I.) = 16.8 (12.1-23.3) mg a.i./L (TWA)NOAEC = 6.04 mg a.i./L (TWA)LOAEC = 12.1 mg a.i./L (TWA)(NOAEC based on sublethal effects including discoloration,surfacing ad lying on the bottom of the test vessel at 12.1 mg/L)Slightly toxicMRID 46829506AcceptableEstuarine/marinefish early life stage(chronic)S-MetolachlorEstuarine/marinespeciesNo data NAFreshwaterinvertebrate acute:48 hours, staticS-Metolachlortechnical(97.6)Water flea(Daphnia magna)EC50(95% C.I.) = 26 (23-30) mg a.i./L (mm)Probit slope (95% C.I.) = 9.1 (5.4-12.8)NOAEC = 4.8 mg a.i./L (mm)LAOEC = 7.9 mg a.i./L (mm)(NOAEC based on mortality and concentration dependentlethargy at≥7.9 mg/L)MRID 43928912Acceptable89Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationSlightly toxicFreshwaterinvertebrate lifecycle: 21 days, staticrenewalS-Metolachlor(Not reported)Water flea(Daphnia magna)NOAEC = 0.1 mg/LLOAEC = 0.5 mg/L(based on number of young per female)E083887Quantitative(Liuet al,2006)Freshwaterinvertebrate lifecycle: 21 days, flowthrough (chronic)S-Metolachlor(98.9)Water flea(Daphnia magna)NOAEC = 5.17 mg a.i./L (mm)LOAEC = 10.0 mg a.i./L (mm)(NOAEC based most sensitive endpoints of length and dryweight; parental and offspring survival also affected)MRID 46829507AcceptableEstuarine/marineinvertebrate acuteS-MetolachlorEstuarine/marinespeciesNo data NAEstuarine/marinemollusc acuteS-MetolachlorEstuarine/marinespeciesNo data NAEstuarine/marineinvertebrate lifecycle: 28 days, flowthrough (chronic)S-MetolachlortechnicalMysid shrimp(Mysidopsis bahia)NOAEC = 0.130 mg a.i./L (mm)LOAEC = 0.250 mg a.i./L (mm)(based on most sensitive endpoints of female length and dryweight; reproduction also affected)MRID 44995902AcceptableBenthic freshwaterinvertebrateMetolachlorFreshwater species No data NABenthicestuarine/marineinvertebrateMetolachlorEstuarine/marinespeciesNo data NAAquatic vascularplant: 14 days, staticS-Metolachlor(97.6)Duckweed(Lemna gibba)EC50(95% C.I.) = 0.021 (0.019-0.023) mg a.i./L (mm)NOAEC = 0.0076 mg a.i./L (mm)LOAEC = 0.018 mg a.i./L (mm)(based on most sensitive endpoint of frond number, biomass alsoaffected; sublethal effects:less root formation at≥0.0076 mg/L,compared to the control; chlorosis at≥0.018 mg/L)MRID 43928931AcceptableAquatic nonvascular plant:120 hours, staticS-Metolachlor(97.6)Green alga(Selenastrumcapricornutum)EC50(95% C.I.) = 0.0080 (0.0026-0.025) mg a.i./L (mm)NOAEC = 0.0015 mg a.i./L (mm)LOAEC = 0.0030 mg a.i./L (mm)(based on cell density; sublethal effects: bloated cells at≥0.0015mg/L; cell fragments at≥0.0030 mg/L)MRID 43928929Acceptable90Study TypeTest Substance(% a.i.)SpeciesToxicity Endpoints andAcute Toxicity Classification (If Applicable)Source& StudyClassificationAquatic nonvascular plant:120 hours, staticS-Metolachlor(97.6)Marine diatom(Skeletonemacostatum)EC50(95% C.I.) = 0.11 (0.091-0.128) mg a.i./L (mm)NOAEC = 0.021 mg a.i./L (mm)LOAEC = 0.081 mg a.i./L (mm)(based on cell density; sublethal effects: bloated cells at≥0.0065mg/L; cell fragments at≥0.081 mg/L)MRID 43928930AcceptableAquatic nonvascular plant:96 hours, staticS-Metolachlor(98.9)Freshwater diatom(Navicula pelliculosa)EC50(95% C.I.) = 18 (17-20) mg a.i./L (TWA)NOAEC = 4.08 mg a.i./L (TWA)LOAEC = 9.9 mg a.i./L (TWA)(based on most sensitive endpoint of area under the growthcurve; cell density and growth rate also affected)MRID 46829509AcceptableAquatic nonvascular plant:96 hours, staticS-Metolachlor(98.9)Cyanobacterium(Anabaena flos-aquae)EC50(95% C.I.) = 21 (19-23) mg a.i./L (mm)NOAEC = 9.6 mg a.i./L (mm)LOAEC = 19 mg a.i./L (mm)(based on most sensitive endpoint of cell density; area under thegrowth curve (biomass and growth rate also affected)MRID 46829510AcceptableAbbreviations: C.I. = confidence interval; form. = formulation; im = initial measured; mm = mean measured; nom = nominal; NA =not applicable; NS = notspecified; TEP = typicalend-use product; TWA = time-weighted average

### 91 

## Appendix E: SIP and STIR Outputs

SIP (v. 1.0)

Table 1. Inputs

Parameter Value

Chemical name metolachlor/S-metolachlor

Solubility (in water at 25 o C; mg/L) 480

Mammalian LD 50 (mg/kg-bw) 2780
Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg-bw) 15
Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Avian LD 50 (mg/kg-bw) 4640
Avian test species mallard duck Body weight (g) of "other" avian species
Mineau scaling factor 1.15

Mallard NOAEC (mg/kg-diet) 800 Bobwhite quail NOAEC (mg/kg-diet) 403 NOAEC (mg/kg-diet) for other bird species Body weight (g) of other avian species NOAEC (mg/kg-diet) for 2nd other bird species Body weight (g) of 2nd other avian species

Table 2. Mammalian Results

Parameter Acute Chronic Upper bound exposure (mg/kg-bw) 82.5600 82.5600 Adjusted toxicity value (mg/kg-bw) 2138.2664 11.5374 Ratio of exposure to toxicity 0.0386 7.1559

Conclusion* Drinking water exposure alone is NOT a potential

concern for mammals Exposure through drinking water alone is a potential concern for

mammals

Table 3. Avian Results

Parameter Acute Chronic Upper bound exposure (mg/kg-bw) 388.8000 388.8000 Adjusted toxicity value (mg/kg-bw) 2409.2059 39.6901 Ratio of exposure to acute toxicity 0.1614 9.7959

Conclusion* Exposure through drinking water alone is a Exposure through drinking water alone is

### 92 potential concern for

birds 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.



### STIR (v. 1.0)



# Welcome to the EFED Screening Tool for Inhalation Risk

This tool is designed to provide the ri sk assessor with a rapid method for determining the potential significance of the inhalation exposure route to birds and mammals in a risk

assessment.



# Input

Application and Chem ical Information

Enter Chemical Name metolachlor/Smetolachlor

Enter Chemical Use Soybean and corn Is the Application a Spray? (enter y or n) y If Spray What Type (enter ground or air) ground

Enter Chemical Molecu lar Weight (g/mole) 283.8 Enter Chemical Vapor Pressure (mmHg) 2.85E-05 Enter Application Rate (lb a.i./acre) 4

Toxicity Properties

Bird

Enter Lowest Bird Oral LD 50 (mg/kg bw) 4640 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 1.58

Mammal

Enter Lowest Rat Oral LD 50 (mg/kg bw) 2780

Enter Lowest Rat Inhalation LC 50 (mg/L) 1.75 Duration of Rat Inhalation Study (hrs) 4 Enter Rat Weight (kg) 0.35



# Output

Results Avian (0.020 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 4.35E-01 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 5.47E-02

Adjusted Inhalation LD 50 1.17E+01

### 93 Ratio of Vapor Dose to Adjusted Inhalation LD 50 4.66E-03 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 4.23E-01 Ratio of Droplet Inhalation Dose to Adjusted

Inhalation LD 50 3.60E-02 Exposure not Likely Significant



### Results Mammalian (0.015 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 4.35E-01 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 6.88E-02

Adjusted Inhalation LD 50 1.04E+02

Ratio of Vapor Dose to Adjusted Inhalation LD 50 6.60E-04 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 5.31E-01 Ratio of Droplet Inhalation Dose to Adjusted

Inhalation LD 50 5.10E-03 Exposure not Likely Significant



# Welcome to the EFED Screening Tool for Inhalation Risk

This tool is designed to provide the risk assessor with a rapid method for determining the potential significance of the inhalation exposure route to birds and mammals in a risk

assessment.



# Input

Application and Chem ical Information

Enter Chemical Name metolachlor/Smetolachlor

Enter Chemical Use Soybean and corn Is the Application a Spray? (enter y or n) y If Spray What Type (enter ground or air) air

Enter Chemical Molecu lar Weight (g/mole) 283.8 Enter Chemical Vapor Pressure (mmHg) 2.85E-05 Enter Application Rate (lb a.i./acre) 4

Toxicity Properties

Bird

Enter Lowest Bird Oral LD 50 (mg/kg bw) 4640 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 1.58

Mammal

Enter Lowest Rat Oral LD 50 (mg/kg bw) 2780

Enter Lowest Rat Inhalation LC 50 (mg/L) 1.75

### 94 Duration of Rat Inhalation Study (hrs) 4 Enter Rat Weight (kg) 0.35



# Output

Results Avian (0.020 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 4.35E-01 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 5.47E-02

Adjusted Inhalation LD 50 1.17E+01

Ratio of Vapor Dose to Adjusted Inhalation LD 50 4.66E-03 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 3.84E-01 Ratio of Droplet Inhalation Dose to Adjusted

Inhalation LD 50 3.27E-02 Exposure not Likely Significant



### Results Mammalian (0.015 kg )
Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 4.35E-01 Maximum 1-hour Vapor Inhalation Dose (mg/kg) 6.88E-02

Adjusted Inhalation LD 50 1.04E+02

Ratio of Vapor Dose to Adjusted Inhalation LD 50 6.60E-04 Exposure not Likely Significant Maximum Post-treatment Spray Inhalation Dose (mg/kg) 4.83E-01 Ratio of Droplet Inhalation Dose to Adjusted

Inhalation LD 50 4.64E-03 Exposure not Likely Significant