UN I TED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D.C., 20460

O F FIC E OF CH E MICAL SAFETY AND POLLUTION PREVENTION

April 9, 2013

ME M ORANDUM PC Code: 12200 1 DP Barcode: 0409662

SUBJECT: Response to DuPont Crop Protection Comme n ts regarding EFED Problem Formulation on th e Registration Review of Su lfometuron Methyl (D409662)

TO: Russell Wasem, Chem ic a l Review Manager Neil Anderson, Branch Chief Risk Management and Implementation Branch 1 Pesticide Re-evaluation Division 508

FROM: Mic hael Barrett, Senior Che 'st

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Environmental Risk Branch V 

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## E~"~ironmental Risk Branch V Env ironm ental Fate and Effects Division (7507P)

The Environmental Fate and Effects Division (EFED) previously completed the preliminary problem formulation for the environmental fate, ecological risk, endangered species, arid human health drinking wa t er exposure assessments to be conducted as part of th e Registration Review of Sulfometuron methyl
, a sulfony l urea herbicide registered for use on forest plantings
, rightsof way, and other non-cropped lands (review dated 12/5 / 2012
, DP Barcode D402497). Comments have been received from the registrant, DuPont Crop Pr otection,

. A summary of the comments an d EFED ' s response follows

.



## List of Comments and EFED Responses

DuPont ha s separately submitted commen ts on ecological effects data needs in a letter from Bridget O'Neill, Global Regulatory Ecotoxico logis t dated 2 / 12 / 2013 and on environmental fate data needs in a l etter from Daniel M. T essier dated 2/13/2013; the full text of these subm i ssions is provided in Appendi x 1. DuPont's comments and EFED's response to these comments is

1 2-[[[[(4
, 6-Dimethyl-2-pyrimidinyl) amino] carbonyl] amino] sulfonyl] benzoic acid
, methyl ester.

### 2

provide d below, first for the environmental fate related comments and then for the ecological effects related comments.



### Environmental Fate Comments

DuPont has commented on partial data deficiencies identified in the Preliminary Problem Formulation with regard to the 835.4100 and the 835.6100 /835.6300 data requirements , both of which refer to specific Environmental Fate data requirements elucidated in the P reliminar y Problem F ormulation. Each section below begins with DuPont’s quote of the EPA document followed by the DuPont response, and then by EFED’s current response.

1. Guideline 835.4100 Aerobic Soil Metabolism

. The Preliminary Problem Formulation stat es on page 35, "Guideline requirements are partially fulfilled ... results from at least four relevant soils of different organic carbon content, pH, clay content and with active microbial biomass must be submitted in order to characterize the variability of aerobic biodegradation ... studies must be conducted on three additional soils." This data requirement appears on page 4 of the Preliminary Work Plan, GDLN 835.4100 and proposes testing of both the Technical Grade Active Ingredient (TGAI), and Typical E nd

- Use Product (TEP).

DuPont Response : Laboratory data has been submitted for the degradation of sulfometuron methyl in Keyport silty loam, pH 6.4, 1.6% organic carbon content {%0C), showing degradation half

- lives (DegT50) of 23 and 29 days in separate tr ials [MRID 42091401, 43174102, 245375]. Data has also been provided from bare soil field studies which demonstrated DT 50 

### values of 12 days in a silty clay loam with soil pH 6.7 and 0.6% OC; 14 days in a silty clay loam with soil pH 6.8 and 1.0% OC; 13 days in a clay soil with soil pH 7.9 and 1.3% OC; and 23 days in a sandy loam with soil pH 7.8 and 0.7% OC [MRID 43212101, 43637101]. Additional field testing returned DT50 values of 14 to 21 days in a silt loam soil with pH 5.5 and 0.8% OC, a sand soil with p H 4.9 and 0.2% OC and a silt loam with pH 6.4 and 0.6% OC [MRID94840].
These data provide a robust characterization of the variability of sulfometuron biodegradation, in eight soils of different pH, %0C and soil texture classification. The degradation pat hway of sulfometuron methyl has been well established in these laboratory and field studies, and the degradation rate data shown in the lab and field studies is consistent. Therefore, DuPont is of the opinion that another laboratory study on additional soi ls is not warranted, as it will not significantly alter the quantitative or qualitative understanding of degradation of sulfometuron methyl in aerobic soil. Laboratory studies of degradation in soil are routinely conducted with either radiolabeled forms of the pesticide active ingredient or technical grade active ingredient (TGAI). Laboratory studies are not routinely conducted with typical end use product (TEP or formulated material) as formulation components have no impact on behavior of the active ingred ient in soil and therefore such a study would add no meaningful information to that obtained with TGAI.

### 3

If it is still deemed necessary to augment the already robust data set on the degradation of sulfometuron methyl in aerobic soil, DuPont proposes the o ption of a laboratory study in aerobic soils with non

- radiolabeled test material to provide additional degradation rate data.

EFED Reply : EFED has reviewed the studies referenced by DuPont as possibly providing sufficient information on sulfometuron meth yl aerobic soil metabolism to justify a full or partial waiver of the requirement to submit the 835.4100 a total of four (two additional to the two already accepted) soils / sites. EFED agrees that the cited field dissipation studies do provide extremely

u seful information relevant to the aerobic soil metabolism of sulfometuron methyl and the formation and decline patterns of degradates at each site. However, ultimately these studies were not under sufficiently controlled conditions to fully isolate the rol e of degradation in the dissipation process. If s ome of these field studies had been conducted to more fully isolate degradation and dissipation processes (with e.g., use of field lysimeters to facilitate a more complete recovery of applied residues and tr acking of losses due to drift, volatilization, runoff) it might be plausible to along with tracking of cumulative average soil temperature and moisture overtime, to closely estimate degradation half

- lives in the field and adjust them for standard condition s as are used in the laboratory. It appears that only some of these characteristics are present in the studies submitted under Guideline 835.6100 (Field Dissipation), for example; daily soil temperature and precipitation data are available, but daily soil moisture measurements are apparently not available and confirmation of recovery within controlled lysimeters or similar devices was not attempted.
A second alternative proposed by DuPont would be to submit these studies under all 835.4100 guideline requi rements with the proposed exception that sulfometuron methyl would not be radiolabeled to facilitate a mass balance accounting. EFED agrees to review, if submitted a formal proposal to fulfill the data requirement without radio labeling of sulfometuron meth yl. S uch a submission would need to demonstrate that the major degradates in aerobic soil are all well

- established such that an accounting of difficult to extract or volatilized residues (which is more easily accomplished with the use of a radiolabel on t he test compound) could be waived in this case only for the two additional aerobic soil metabolism studies.
EFED concurs with DuPont’s comment regarding the use of TGAI versus TEP.

2. Guideline 835.6100 /835.6300 (Supporting) Environmental Chemistry Meth ods; Independent Laboratory Validation

. The Preliminary Problem Formulation states on page 35, "State of the art ECMs in soil and water and ILVs used in sulfometuron methyl environmental fate studies are requested at this time."

DuPont response : DuPont concurs with this statement. New soil and water analytical methods can be made available for sulfometuron methyl and metabolitesiN

- X0993, IN

- D5803 and IN

- 581, and will be provided upon request along with independent laboratory validation

. EFED Reply :

### 4

Thes e data needs have been communicated to the Pesticide Re

- Evaluation Division for appropriate action.



### Ecological Effects Comments There were six issues related to the available ecological effects data in the Preliminary Problem formulation that DuPont comme nted on (see below), in each case DuPont has concurred with EFED conclusions regarding the use of these data. EFED thanks DuPont for carefully reviewing the document and responding in detail. The context for each of these issues in the Problem Formulation is included in Appendix 1.

Issue 1: section 7, page 37 , Guideline 850.1025. DuPont Comment 1 : DuPont agrees with the agency that repeating these studies would not likely affect the risk assessment conclusions.

Issue 2 : section 7, page 38 ; Guideline 85 0.1350. DuPont Comment 2 : DuPont agrees with the agency’s decision to use toxicity data for freshwater invertebrates to characterize toxicity for estuarine/marine invertebrates.

Issue 3 : section 7, page 38; Guideline 850.1400. DuPont Comment 3 : DuPont ag rees with the agency’s decision to use chronic exposure toxicity data for freshwater and estuarine/marine fish for another sulfonylurea with a similar toxicity profile to characterize chronic exposure toxicity for freshwater and estuarine/marine fish for S ulfometuron Methyl.

Issue 4 : section 7, page 38; Guideline 850.2100. DuPont Comment 4 : DuPont agrees with the agency’s decision to characterize toxicity to passerines from acute exposure to Sulfometuron Methyl by using all acute toxicity data for passerines for other sulfonylureas with a similar toxicity profile and the same mode of action.

Issue 5 : section 7, page 39; Guideline 850.2300. DuPont Comment 5 : DuPont agrees with the agency’s decision to characterize toxicity to birds from chronic expo sure to Sulfometuron Methyl by using data from other sulfonylureas with a similar toxicity profile and the same mode of action.

Issue 6 : section 7, page 38; Non

- Guideline ( Special study for non

- target plant reproductive toxicity with TEP ). DuPont Comment 6 : DuPont agrees

Issue 6 : section 7, page 3 9 ; Agency comment on the use of Guideline 850. 415 0.

### 5

DuPont Comment 6 : DuPont agrees with the agency that reproductive toxicity effects are likely to occur at similar concentrations as those observed in vegetativ e vigor studies, which have already been conducted for Sulfometuron Methyl and submitted to the agency for review.



## Appendix 1: DuPont Crop Protection Letters commenting on the EFED Preliminary Problem Formulation for Sulfometuron MethylFebruary 13, 2013

United States Environmental Protection Agency

Office of Prevention, Pesticides and Toxic Substances Risk Management and Implementation Branch II Pesticide Re-evaluation Division

Subject: DuPont Response to: Sulfometuron Methyl PC Code 122201 Case Number 3136 DuPont Crop Protection Stine-Haskell Research Center 1090 Elkton Road Newark, Delaware 19711

• USEPA Registration Review: Pesticide Dockets Opened For Review and Comment -December 14, 2012; HQ-OPP-2012-0433-0001

• Preliminary Problem Formulation For Environmental Fate, Ecological Risk, Endangered Species, and Human Health Drinking Water exposure Assessments for Sulfometuron Methyl- December 5, 2012; HQ-OPP-2012-0433-0002

• Sulfometuron Methyl Preliminary Work Plan, Registration Review Initial Docket Case Number 3136- December, 2012; HQ-OPP-2012-0433-0011

Submitted by: Daniel M. Tessier, PhD Principal Investigator DuPont Crop Protection Stine Haskell Research Center 1090 Elkton Rd Newark, DE 19711

DuPont appreciates the opportunity to submit comment in response to the opening of the Registration Review process for sulfometuron methyl. These comments are in specific response to EPA's careful review of the existing Environmental Fate data for sulfometuron methyl and the proposed data requirements specific to Environmental Fate.

1. 835.4100 [162-1] Aerobic Soil Metabolism

The Preliminary Problem Formulation states on page 35, "Guideline requirements are partially fulfilled

... results from at least four relevant soils of different organic carbon

H du Pont de Neroours and Companycontent, pH, clay content and with active microbial biomass must be submitted in order to characterize the variability of aerobic biodegradation

... studies must be conducted on three additional soils." This data requirement appears on page 4 of the Preliminary Work Plan, GDLN 835.4100 and proposes testing of both the Technical Grade Active Ingredient (TGAI), and Typical End-Use Product (TEP).

DuPont Response:

Laboratory data has been submitted for the degradation of sulfometuron methyl in Keyport silty loam, pH 6.4, 1.6% organic carbon content {%0C), showing degradation half-lives (DegT 50 ) of 23 and 29 days in separate trials [MRID 42091401, 43174102, 245375]. Data has also been provided from bare soil field studies which demonstrated DTso values of 12 days in a silty clay loam with soil pH 6.7 and 0.6% OC; 14 days in a silty clay loam with soil pH 6.8 and 1.0% OC; 13 days in a clay soil with soil pH 7.9 and 1.3% OC; and 23 days in a sandy loam with soil pH 7.8 and 0.7% OC [MRID 43212101, 43637101]. Additional field testing returned DT 50 values of 14 to 21 days in a silt loam soil with pH 5.5 and 0.8% OC, a sand soil with pH 4.9 and 0.2% OC and a silt loam with pH 6.4 and 0.6% OC [MRID94840].

These data provide a robust characterization of the variability of sulfometuron biodegradation, in eight soils of different pH, %0C and soil texture classification. The degradation pathway of sulfometuron methyl has been well established in these laboratory and field studies, and the degradation rate data shown in the lab and field studies is consistent. Therefore, DuPont is of the opinion that another laboratory study

on additional soils is not warranted, as it will not significantly alter the quantitative or qualitative understanding of degradation of sulfometuron methyl in aerobic soil.

Laboratory studies of degradation in soil are routinely conducted with either radiolabeled forms of the pesticide active ingredient or technical grade active ingredient (TGAI). Laboratory studies are not routinely conducted with typical end use product (TEP or formulated material) as formulation components have no impact on behavior of the active ingredient in soil and therefore such a study would add no meaningful information to that obtained with TGAI.

If it is still deemed necessary to augment the already robust data set on the degradation of sulfometuron methyl in aerobic soil, DuPont proposes the option of a laboratory study in aerobic soils with non-radiolabelled test material to provide additional degradation rate data.2. 835.6100/835.6300 (Supporting) Environmental Chemistry Methods; Independent Laboratory Validation

The Preliminary Problem Formulation states on page 35, "State of the art ECMs in soil and water and ILVs used in sulfometuron methyl environmental fate studies are requested at this time."

DuPont response:

DuPont concurs with this statement. New soil and water analytical methods can be made available for sulfometuron methyl and metabolitesiN-X0993, IN-D5803 and IN-581, and will be provided upon request along with independent laboratory validation

In summary, DuPont asserts that the degradation route and rate of sulfometuron methyl in aerobic soil is well established and well understood, based on data generated in

numerous and varied soils, and further that an additional laboratory study would not offer any meaningful improvement to a qualitative or quantitative understanding of sulfometuron methyl degradation or substantively alter the conclusions of environmental fate risk assessment.

DuPont will provide an updated ECM and ILV for sulfometuron methyl analysis in soil and water upon request.

Respectfully,

# ~A~~ Daniel M. TessierDuPont Crop Protection Stine

- Haskell Research Center P.O. Box 30 Newark, DE 19714

- 0030


### February 12 , 2013
United States Environmental Protection Agency Office of Prevention, Pesticides and Toxic Substances Risk Management and Implementation Branch II Pesticide Re

- Evaluation Division
Subject: DuPont Response to: Sulfometuron Methyl PC Code 122201 Case Number 3136 USEPA Registration Review: Pesticide Dockets Opened For Review and Comment

– December 14, 2012; HQ

- OPP

- 2012

- 0433

- 0001 Preliminary Problem Formulation For Environmental Fate, Ecological Risk, Endangered Species, and H uman Health Drinking Water exposure Assessments for Sulfometuron Methyl

– December 5, 2012; HQ

- OPP

- 2012

- 0433

- 0002 Sulfometuron Methyl Preliminary Work Plan, Registration Review Initial Docket Case Number 3136

– December, 2012; HQ

- OPP

- 2012

- 0433

- 0011

Submit ted by: Bridget O’Neill, Global Regulatory Ecotoxicologist E.I. du Pont de Nemours & Company 1007 Market Street Wilmington, DE 19898
E.I. du Pont de Nemours & Company is supporting the Registration Review of the herbicide active ingredient Sulfometuron Methyl . As part of that effort DuPont is herein submitting comments to the Agency in response to December 12, 2012 Federal Register Notice, via the docket as designated: Docket ID Number EPA

- HQ

- OPP

- 2012

- 0 433

. DuPont warmly welcomes the opportunity to com ment on the data gaps listed in the registration review document. The following comments are applicable to Environmental Effects as discussed in the EFED Re registration Review, section 7 , page 3 7. Each subject is characterized as an issue, followed by a comment.

Issue 1: section 7, page 37, the preliminary problem formulation document states: Guideline 850.1025

– Acute toxicity estuarine/marine invertebrate (bivalve); Guideline 850.1035

– Acute toxicity estuarine/marine invertebrate (mysid); Guideline 850.1075

– Acute toxicity estuarine/marine fish: Acceptable acute toxicity data for an estuarine/marine bivalve, mysid, and fish are not available. Submitted studies for these data requirements with a 48

- hr IC50 > 38.2 mg a.i ./L (MRID 41672805), a 48

- hr LC50 > 44.8 mg a.i./L (MRID 41672803), and a 48

- hr LC50 > 45 mg a.i./L (MRID 41672804), respectively, are classified as supplemental due to high variability in measured test concentrations and uncertainty in exposure to dissolv ed sulfometuron methyl ( i.e. , test samples were not centrifuged prior to analysis). Although these deficiencies could have rendered the study classifications as invalid, the studies are considered to provide some useful information for the Registration Rev iew ecological risk assessment ( i.e. , an indication of a lack of toxicity at or near solubility limits in test solutions).DuPont Crop Protection Stine

- Haskell Research Center P.O. Box 30 Newark, DE 19714

- 0030


### Furthermore, when viewed in the context of predicted EECs ( i.e. , a maximum peak concentration of 0.0315 mg/L in water, see Table 5)
, the bioavailable (dissolved) portion sulfometuron methyl would have to be approximately 1200

- 1400 fold lower than the highest measured test concentrations (~ 38

- 45 mg/L) for risks to be evident. Therefore, repeating these studies would not likely affect th e risk assessment conclusions, and new studies are not required.

DuPont Comment 1: DuPont agrees with the agency that repeating these studies would not likely affect the risk assessment conclusions.

Issue 2: section 7, page 38, the preliminary problem formulation document states: Guideline 850.1350

– Estuarine/marine invertebrate life cycle: Aquatic invertebrate life cycle toxicity data for an estuarine/m arine invertebrate are required under 40 CFR Part 158 if the product is expected to enter the enviro nment in significant concentrations because of its expected use or mobility patterns. No studies have been submitted for this data requirement. Given that the acute toxicity of sulfometuron methyl to aquatic animals is very low (slightly to practically

non

- toxic), the NOEC for the freshwater invertebrate life cycle study (MRID 41672806) was set at the highest test concentration, and there is no evidence to indicate that estuarine/marine animals are substantially more sensitive to sulfometuron methyl than freshwater animals, fulfilling this data requirement has a low potential to add value to the Registration Review risk assessment. In the absence of this data, toxicity to estuarine/marine invertebrates from chronic exposure to sulfometuron met hyl will be characterized using toxicity data for freshwater invertebrates. New study is not required.

DuPont Comment 2: DuPont agrees with the agency’s decision to use toxicity data for freshwater invertebrates to characterize toxicity for estuarine/mari ne invertebrates.

Issue 3: section 7, page 38, the preliminary problem formulation document states: Guideline 850.1400

– Estuarine/marine and freshwater fish early

- life stage: Early

- life stage toxicity data for a freshwater fish are required under 40 CFR Part 158. Early

- life stage toxicity data for an estuarine/marine fish are required under 40 CFR Part 158 if the product is expected
to enter the environment in significant concentrations because of its expected use or mobility patterns. No studies have bee n submitted for this data requirement. Given that the acute toxicity of sulfometuron methyl to aquatic animals is very low (slightly to practically non

- toxic), the NOEC for the freshwater invertebrate life cycle study (MRID 41672806) was set at the highest test concentration, and there is no evidence to indicate that estuarine/marine animals are substantially more sensitive to sulfometuron methyl than freshwater animals, fulfilling these data requirements has a low potential to add value to the Registration Review risk assessment. In the absence of this data, toxicity to freshwater fish from chronic exposure to sulfometuron methyl will be estimated using a freshwater fish ACR for another sulfonylurea with a similar toxicity profile and the same mode of actio n ( e.g. , flazasulfuron, PC code 119011; see 2008 RED, USEPA, 2008) to extrapolate from existing acute toxicity data for freshwater fish. For estuarine/marine fish, a similar approach may be taken. A new study is not required.

DuPont Comment 3: DuPont agrees with the agency’s decision to use chronic exposure toxicity data for freshwater and estuarine/marine fish for another sulfonylurea with a similar toxicityDuPont Crop Protection Stine

- Haskell Research Center P.O. Box 30 Newark, DE 19714

- 0030


### profile to characterize chronic exposure toxicity for freshwater and estuarine/marine fish for Sulformeturon Methyl.

Issue 4: section 7, page 38, the preliminary problem formulation document states: Guideline 850.2100

– Avian oral toxicity, passerine species: Acute oral toxicity data for a passerine species are required under the new 40 CF R Part 158. No studies have been submitted for this data requirement. The acute toxicity of sulfometuron methyl to birds and mammals is very low (practically non

- toxic). In addition, acute toxicity data for a passerine species is available for flazasulfuro n (PC code 119011), a sulfonylurea with a similar toxicity profile and the same mode of action as sulfometuron methyl. This study (MRID 47939912) indicates that flazasulfuron is practically non

- toxic to the zebra finch ( Taeniopygia guttata ) on an acute oral basis (LD50 > 2000 mg a.i./kg

- bw). Therefore, fulfilling this data requirement has a low potential to add value to the Registration Review risk assessment. In the absence of this data, toxicity to passerines from acute exposure to sulfometuron methyl will be characterized using all acute toxicity data for other sulfonylureas with a similar toxicity profile and the same mode of action that are available at the time of the Registration Review risk assessment. A passerine
acute study with SMM is not requi red.

DuPont Comment 4: DuPont agrees with the agency’s decision to characterize toxicity to passerines from acute exposure to Sulfometuron Methyl by using all acute toxicity data for passerines for other sulfonylureas with a similar toxicity profile and t he same mode of action.

Issue 5: sec tion 7, page 39, the preliminary problem formulation document states: Guideline 850.2300

– Avian reproduction, upland game and waterfowl species: Avian reproductive toxicity data for water fowl and upland game species are required under 40 CFR Part 158. No studies have been submitted for this data requirement. The acute toxicity of sulfometuron methyl to birds and mammals is very low (practically non

- toxi c). In addition, there is ample avian reproductive toxicity data available for other sulfonylureas with a similar toxicity profile and the same mode of action ( e.g. , halosulfuron, PC code 128721, NOAEC = 1010 mg a.i./kg

- diet, MRIDs 47792801 and 47792802; p rimisulfuron, PC code 128973, NOAEC = 500 mg a.i./kg

- diet, MRID 40512004; rimsulfuron, PC code 129009, NOAEC = 1250 ppm, D358867, D358872; flazasulfuron, PC code 119011, NOAEC = 484 mg a.i./kg

- diet, MRID 46220975). Avian reproductive NOECs for these sulfonylureas are 1 to 2 orders of magnitude greater than the peak sulfometuron methyl EEC of 90 mg/kg

- diet (for birds consuming short grass) as calculated for the 2008 ecological risk assessment for the reregistration of sulfometuron methyl (USEPA, 2008) suggesting there is little concern for risk to birds from chronic exposure to sulfometuron methyl. Therefore, fulfilling this data requirement has a low potential to add value to the Registration Review risk assessment. In the absence of this data, toxicit y to birds from chronic exposure to sulfometuron methyl will be characterized using chronic toxicity data for other sulfonylureas with a similar toxicity profile and the same mode of action. New studies are not required.

DuPont Comment 5: DuPont agrees with the agency’s decision to characterize toxicity to birds from chronic exposure to Sulfometuron Methyl by using data from other sulfonylureas with a similar toxicity profile and the same mode of action.DuPont Crop Protection Stine

- Haskell Research Center P.O. Box 30 Newark, DE 19714

- 0030



### Issue 6: section 7, page 39, the pr eliminary problem formulation document states: Non

- Guideline

– Special study for non

- target plant reproductive toxicity with TEP: A DCI for this study, previously published as a result of the 2008 RED for sulfometuron methyl, has not been fulfilled. EFED's Plant Technical Team (PTT) conducted an analysis of available SU plant reproduction data from the open literature and the registrant

- submitted data for chlorsulfuron and concluded that data from the 850.4150 vegetative vigor guideline study are sufficiently protective of potential impacts to plant reproduction. Acetolactate synthase (ALS) inhibitors primarily affect metabolically

- active meristem tissues. When plants are exposed at a young, vigorously growing life

- stage, effects are expressed prim arily as inhibition of vegetative growth ( i.e. biomass, shoot length). As plants mature these effects are less pronounced. However, as plants enter their reproductive life

- stage, the metabolically

- active tissue will include flower and seed production. Plan ts exposed to SU herbicides during the reproductive life stage are likely to exhibit adverse effects on reproduction, generally expressed as reduced seed number or reduced seed weight. Based on the latest data analysis, these effects are expected to occur at similar concentrations to those effects determined in the guideline vegetative vigor studies (850.4150). Therefore, fulfilling this DCI has a low potential to add value to the Registration Review risk assessment, and a study is not required.

DuPont Com ment 6 : DuPont agrees with the agency that reproductive toxicity effects are likely to occur at similar concentrations as those observed in vegetative vigor studies, which have already been conducted for Sulfometuron Methyl and submitted to the agency for review.
DuPont would like to thank the Agency for this opportunity to comment in response to the opening of the preliminary problem formulation document of Sufometuron Methyl

. Sincerely

Bridget O’Neill, PhD Global Regulatory Ecotoxicologist