# •

UN IT E D S T ATES ENV IRO N M EN T A L PRO TEC TIO N AGENCY WASHINGTO N D.C

., 20460

OF F IC E OF CH EM ICAL SAF ETY A N D PO L LUTIO N PR EVE NT IO N



### PC Code: 128973 DP Barcode: 0394823

MEMORANDUM March 

### 1, 2012

Subject:

To:



### From: Registration Review: Preliminary Problem Fonnulation for Environmental Fate and Ecological Risk, Endangered Species, and Drinking Water Assessments for Primisulfuron methyl (Case 

## # 7220)

Kaitlin Keller

, Team Lead (RM 53) Michael Goodis

, Branch Chief

, RMIB III Pesticide Re-Evaluation Division (7508P) 

# 00**~~}II'l/** Stephen Carey

, Biologist**/""~ u.**  

### Andrew Shelby, Physical Scientist

## ~.......t..---\ /3

- I

- 

### Ie.. 

### Environmental Risk Branch 6 'v-

- 

# 17

Environmental Fate and Effects Division (7507P)

Reviewed 

### by: Ibrahim Abdel-Saheb

, Ph.D.

, Environmental Scientist Brian Kiernan

, Biologist

Through: Environmental Risk Branch 6 Environmental Fate and Effects Division (7507P)

Mark Corbin, Branch Chief Environmental Risk Branch 6 Environmental Fate and Effects Divi s ion (7507P)

The Environmental Fate and Effects Div i s ion (EFED) has completed the preliminary problem fonnulation (attached) for the environmental fate and ecological risk

, endangered species, and drinking water assessments to be 

### conducted as part of the Registration Review of the herbicide primisu l furon methyl (primisulfuron ; PC Code 128973). Primisulfuron methyl is coformulated with other registered chemicals

- in end use products (prosulfuron and dicamba). Functioning as the first stage of the risk assessment proce ss for Registration Review, thi s problem formulation provides an overview of what is currently known about the en v ironmental fate and ecological effects associated with primisulfuron methyl and its degradate CGA-171683. It also describes the preliminary ecologic a l ri s k hypothesis and analysis plan for evaluating and characteri z ing risk to non

- target species and the environment in support of registration review.

I



# ,

### 2 Data Gaps

The available environmental fate and transport data are considered incomp lete and inadequate for the purposes of risk assessment. The following data gaps exist:

**•** Submission of an acceptable aerobic aquatic metabolism (OPPTS guideline # 835.4300) study is necessary to understand the degradation of primisulfuron methyl in oxygen abundant aquatic environments. The guideline stipulates that at least two different sediment:water systems be submitted that are similar to the potential use sites in the United States. In the absence of this data, the model input for aerobic soil metabolism is doubled to conservatively estimate the model input for aerobic aquatic metabolism.

**•** Submission of an acceptable anaerobic aquatic metabolism (OPPTS guideline # 835.4400) study is necessary to understand the degradation of primisulfuron methyl in
oxygen

- limiting environments. In the absence of this data, the model input for anaerobic soil metabolism is doubled to conservatively estimate the model input for anaerobic aquatic metabolism.

**•** There are currently terrestrial field dissipation studies (O PPTS guideline # 835.6100) under review by the Agency. Until the review is complete, EFED cannot be certain the data are sufficient for risk assessment. This study is necessary to understand the dissipation of primisulfuron methyl in field conditions.

**•** Supp lemental to the terrestrial field dissipation studies are the independent laboratory method validation, and environmental chemistry methods used for the field study.

The available effects dataset is considered incomplete for the purposes of risk assessme nt. The following data gaps exist:

**•** Primisulfuron methyl

- OPPTS 850.2100 ; An avian acute oral study with a passerine is necessary for risk assessment. Until the data is available , EFED cannot be certain the data are sufficient for an ecological risk asse ssment on birds

.

**•** Primisulfuron methyl

- Non

- guideline ; Terrestrial Plant Reproduction Study will be necessary for risk assessment to fully evaluate the effects of primisulfuron methyl to plants at different stages

.

**•** Degradate CGA171683

- OPPTS 850.2300; rep roduction toxicity to upland game bird and waterfowls

. Toxicity data on the environmental relevant degradate CGA 171683 of primisulfuron methyl is necessary for risk assessment since CGA171683 is persistent in the environment with 75% of the degradate remaining after 12 months

. Additional detail on the current data gaps for environmental fate and effects for primisulfuron methyl is provided in Section 8.0.

### 3 OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION



# Problem Formulation for the Environmental Fate and Ecological Risk, Endangered Species, and Drinking

Water Assessments in Support of the Registration Review of Primisulfuron methyl

methyl 2-[[[[[4,6-bis(difluoromethoxy)-2-pyrim idinyl]amino]carbonyl]amino]sulfonyl]benzoate 

## CAS Registry Number: 86209-51-0 PC Code: 128973

P

repared by: Stephen Carey, Biologist Andrew Shelby, Physical Scientist U. S. Environmental Protection Agency Office of Pesticide Programs E nvironmental Fate and Effects Division E nvironmental Risk Branch I V 1200 Pennsylvania Ave., NW M

ail Code 7507P Washington, DC 20460 R eviewed by: Brian Kiernan, Biologist Ibrahim Abdel-Saheb, Ph.D ., Environmental Scientist Mark Corbin, Branch Chief



### March 1, 2012

### 4 1. Purpose

The purpose of this problem formulation is to provide an understanding of what is known about the environmental fate and ecological effects of the registered uses of primisulfuron methyl (PC Code 128973 ). Primisulfuron methyl belongs to the sulfonylurea c lass of herbicides and it is applied for selective control of annual and perennial broadleaf weeds and certain monocots in agricultural crop areas. Crop uses include field corn, popcorn, and K entucky bluegrass grown for seed and sod . This herbicide is applied as post

- emergen t treatment and may be used on established planting s

. Primisulfuron methyl is an acetolactate synthase (ALS) inhibitor. ALS is an important enzyme for the synthesis of branched chain amino acids. This metabolic pathway is present only in plants. Primisulfuron methyl is absorbed by the foliage and roots of plants. This document will provide a plan for analyzing data relevant to primisulfuron methyl and for conducting environmental fate and ecological risk, endangered species, and drinking water assessments for its registered uses. Additionally, this problem formulation is intended to identify data gaps, uncertainties, and potential assumptions used to address those uncertainties relative to characterizing the ecological risk assoc iated with the registered uses of primisulfuron methyl

.
2. Problem Formulation

2.1. Nature of Regulatory Action

Under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), all pesticides distributed or sold in the United States generally mus t be registered by the Environmental Protection Agency (EPA). As part of determining whether a pesticide can be registered in the U.S., the Agency evaluates its safety to non

- target species based on a wide range of environmental and health effects studies . In 1996, FIFRA was amended by the Food Quality Protection Act, and the Agency was mandated to implement a new program for the periodic review of pesticides, i.e

., Registration Review ( http:// www.epa.gov/oppsrrd1/registration_review/ ). The Registration Review program is intended to ensure that, as the ability to assess risk evolves and as policies and practices change, all registered pesticides continue to meet the statutory standard of no

unr easonable adverse effects to human health and the environment. Changes in science, public policy, and pesticide use practices occur over time. Through the Registration Review program, the Agency periodically reevaluates pesticides to make sure that as ch ange occurs, products in the marketplace can be used safely.

As part of the implementation of the Registration Review program pursuant to Section 3(g) of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), the Agency is beginning its evaluatio n of primisulfuron methyl to determine whether it continues to meet the FIFRA standard for registration. This problem formulation for the environmental fate, ecological risk, endangered species, and drinking water assessment chapter in support of the Regi stration Review will be posted in the initial docket, which will open the public phase of the review process.

### 5 2.2. Previous Risk Assessments

In 198 8, the Agency granted an Experimental U se Permit for primisulfuron methyl on corn. In 1990 , the Agency produced a hazard assessment for the full registr ation of primi sulfuron methyl for use as selective weed control in corn . At that time, there were many data gaps for primisulfuron methyl , including batch equilibrium

, terrestrial field dissipation , avian

r eproduction, freshwater fish, freshwater invertebrate, estuarine invertebrate, fish early life stage, fish life cycle and fish bioaccumulation studies. Due to unknown mobility, leaching to groundwater was also a potential concern.

In 19 91 , the Agency r eviewed a request to allow aerial application of primisulfuron methyl on corn and concluded that the potential for adverse effects to nontarget terrestrial and aquatic plants would be dramatically increased. No ne of the previously identified data gaps wer e addressed for this action.

In 1994, the Agency qualitatively reviewed all sulfonylurea herbicides and recommended that all aerial applications be rescinded and all ground applications be reconsidered due to a potential for serious adverse effects based on evidence from incidents and field studies.

In 1998, EPA received t wo Section 18 requests ( emergency use exemptions; 1998) from Washington and Idaho were for weed control in Kentucky bluegrass grown for seed to control quackgrass, cheatgrass, downy brome , windgrass and wild oat. Approximately 71,000 acres were treated with primisulfuron methyl at 0. 036 lb a.i./A/yr or a total of 2,500 lb a.i.

EFED conducted an ecological fate and effects hazard assessment dated October 4, 1991 for primisulfuron methyl ; however, no ecological risk assessment was conducted for primisulfuron methyl

.
3. Stressor Source and Distribution

3.1. Mechanism of Action

Primi sulfuron methyl ’s mode of action is the inhibition of amino acid synthesis in plants through inhibition of acetolactate synthase (ALS). ALS is the first common enzyme in the biosynthesis of branched

- chain amino acids (valine, leucine

, and isoleucine). ALS inhibition in plants adversely affects plant growth and reproduction. Although acetolactate is present i n mammals, the biosynthesis of branch chain amino acids occurs only in plants. Chlorsulfuron (PC Code 118601), the most studied pesticidal sulfonyl urea (SU) , does not affect acetolactate forming enzymes in mammalian cells (Nakata, 1991). SUs in general are less toxic to animals than plants.

### 6 3.2. Overview of Pesticide Use and Usage

Primi sulfuron methyl belongs to the sulfonylurea class of herbicides and it is applied for selective control of annual and perennial broadleaf weeds and certain monocots in field corn, popcorn , and Kentucky bluegrass grown for seed and sod . This herbicide is applied as a post

emergence treatment and may be used on established planting. According to the Biological and Economic Analysis Division’s (BEAD) Screening Level Usage Analy sis (SLUA; USEPA 2011), roughly 30 ,000 lbs of primi sulfuron methyl is applied annually to corn in the U.S. Usage data for Kentucky bluegrass is unavailable.

Primi sulfuron methyl is also co

- formulated with other active ingredient s , prosulfuron and dicamba sodium salt, in separate end use products

. Primi sulfuron methyl is formulated as a water dispersible granule intended for tank mixing with water. The application rate varies with use site, stage of weed growth, and coformulants ; maximum single application rate is 0. 036 lbs a.i./A for all use patterns and aerial applications may be performed . For further information, see ‘BEAD Chemical Profile for Registration Review: Primisulfuron methyl (1 28973 )’ ( EPA 2011).

Based on private m arket survey data for the most recent years of 2008

- 2010, use on corn averaged approximately 8,000 lb s for 350,000 treated acres ( EPA 2011 ). Over the last decade usage in corn has significantly declined. The reason for the decline is not clear, but it coul d be due to the wider use of Roundup ready corn in U.S. field corn production. For 2008

- 2010, the states with the most use in term of pounds a.i. applied were Illinois (30%), Nebraska (12%), Pennsylvania (11%), and Indiana (11%).

3.3. Environmental Fate a nd Transport

Primisulfuron methyl is moderately persistent in soil with half lives ranging from 30 to 89 days in aerobic and anaerobic conditions. It is mildly water soluble with a relatively low octanol/water partition, and it is relatively stable to ph otolysis. Primisulfuron methyl has been described as mobile in sandy soils with low organic content and is not likely to bioaccumulate in aquatic organisms. Primisulfuron methyl is stable to hydrolysis at environmentally relevant pHs. Therefore, primisu lfuron methyl may be expected to persist in aquatic environments considering aerobic and anaerobic aquatic metabolism studies are unfulfilled data requirements.

Table 1 presents the general physical and chemical, as well as the available environmental fate properties of primisulfuron methyl

.

### 7 Table 1

. General Chemical Properties and Environmental Fate Properties of Primisulfuron Methyl

. Parameter Value Reference (MRID #) /Comment Physical/Chemical Parameters
Molecular mass 468.34 g/mol 40331203 Vapor pressure (2 5 °C) 3.8 x 10 - 8 torr 40331203 Henry’s Law Constant Not Available Water solubility (2 0 °C) 70 mg/L (in water) 40331203
Octanol

- water partition coefficient (K OW ) 1.58 40331203 Dissociation Constant (pKa) 5.1 40331203 Mobility Soil Partitioning Coefficient (Koc, 1/n) 74.5, 57.4, and 66.3 mL/goc 0.9135, 0.9845, and 0.9595 (1/n values) 40331264 40856513 41869302 41869304
Persistence in Water Hydrolysis half

- life (25°C ) pH 7 & 9: Stable pH 5: >30 days 40331261

Aqueous photolysis half

- life (25°C) Stable 40856508 40856509 41418611 Aerobic aquatic metabolism half

- life No available data Anaerobic aquatic metabolism half

- life No available data
Persistence in Soil Soil photolysis Stable 41418612

Aerobic soil metabolism half

- life (25°C) 63 days 30 days 40331263 41418613

Anaerobic soil metabolism 41 days 89 days 41418614 40331263 Field Dissipation Terrestrial field dissipation half

- life (DT 50 ) 5

- 9 days All studies are supplemental 40512015 40512016 40512017 40512018 40512019 Aquatic Bioconcentration
Bioconcentration Factor (BCF) in fish Low Kow indicates low potential to bioaccumulate.



### Primisulfuron methyl is not volatile, having a vapor pressure of 3.8 x 10 - 8 

### torr. It is stable to hydrolysis at pH 7 and 9, but at pH 5

, some amount of degradation was observed with a half

- life greater than 30 days (MRID 40331261). It is also stable to photolysis. The K ow 

### is low and does not indicate a po tential to bioaccumulate.

The mobility of primisulfuron methyl appears to vary with soil types and correlate with CEC and clay content. Primisulfuron methyl will have a tendency to leach in sandy, inorganic soils.

### 8 The degradation of primisulfuron me thyl in aerobic soil ranged from 30 to 63 days, and is considered moderately persistent in soil (MRID s 40331263 and MRID 41418613). Data for one of the major metabolites, (CGA

- 171683), show that the metabolite is persistent and will remain in the soil aft er the parent has degraded (present at 75% of applied concentration at 12 months, MRID 41418613). CGA

- 171683 was also the primary degradation product of pyrimidine

labeled primisulfuron methyl in anaerobic soil reaching 75% of applied radioactivity at 3 m onths (MRID 41418614). This degradation product consists of the pyrimidine group from parent primisulfuron methyl cleaved at the first amine group in the sulfonylurea group. Phenyl

- labeled primisulfuron methyl is stable to hydrolysis in neutral and alkal ine conditions but degrades at pH 5. The primary degradation product detected is CGA

- 120844, a benzoate group cleavage product. Because these metabolism studies were conducted with pyrimidine

- labeled primisulfuron methyl and the hydrolysis study was con ducted with phenyl

- labeled primisulfuron methyl, it appears that different major degradates are forming. However, CGA

- 171683 and CGA

- 120844 appear to be products of the same cleavage process.

There is no available data for aerobic or anaerobic aquatic metabolism, therefore for the purposes of risk assessment the compound is assumed to have half lives double that of aerobic , 126 days, and anaerobic soil

, 178 days, respectively (USEPA, 2009).

Supplemental terrestrial field dissipation data reported resul ts with dissipation half

- lives ranging from 5 to 9 days (MRID 40512015, 40512016, 40512017, 40512018, 40512019). It is important to note that the pattern of formation and decline of the degradates was not addressed. The compound may leach in low organic matter soils (which is consistent with other sulfonylurea herbicides), however adequate field dissipation data have not yet been reviewed to characterize the extent of potential ground water contamination.

3.3.5 . Bioaccumulation

T he low K ow 

### of 1.58 indicates a lo w potential for bioaccumulation. Therefore, bioaccumulation studies have not been required.

4. Receptors

The receptor is the biological entity that is exposed to the stressor (EPA, 1998.) Given its widespread use, all types of biological receptors (birds, mammals, terrestrial plants, freshwater fish, etc.) are expected to be potentially exposed to primisulfuron methyl.

Consistent with the process described in the Overview Document (EPA, 2004), this risk
assessment uses a surrogate species approach in its evaluation of primisulfuron methyl. T oxicological data generated from surrogate test species, which are intended to be representative of broad taxonomic groups, are used to extrapolate to potential effects on a varie ty of species (receptors) included under these taxonomic groupings.

A cute and chronic toxicity data from studies submitted by pesticide registrants along with the available open literature are used to evaluate the potential direct effects of the herbici de to the

### 9 aquatic and terrestrial receptors identified in this section. This includes toxicity data on the technical grade active ingredient, degradates, and when available, formulated products (e.g. “Six

Pack” studies of mammalian toxicity). The open lit erature studies are identified through EPA’s ECOTOX database ( http://cfpub.epa.gov/ecotox/ ), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and w ildlife. The evaluation of both sources of data can also provide insight into the direct and indirect effects of primisulfuron methyl on biotic communities from loss of species that are sensitive to the chemical and from changes in structure and function al characteristics of the affected communities.

Table 3 provides a summary of the taxonomic groups and the surrogate species tested to help understand potential acute ecological effects of pesticides to these non

- target taxonomic groups. In addition, the table provides a preliminary overview of the potential acute toxicity of primisulfuron methyl by providing the acute toxicity classifications.

Table 3 . Test Species Evaluated for Assessing Potential Ecological Effects of Primisulfuron methyl and the Associated Acute Toxicity Classification Taxonomic Group Example(s) of Surrogate Species Acute Toxicity Classification

Birds 1 

### Mallard duck ( Anas platyrhynchos ) Bobwhite quail ( Colinus virginianus ) Passerine bird Practically nontoxic a



### Mammals Laboratory rat ( Rattus norvegicus ) Practically non toxic Insects Honey bee ( Apis mellifera L. ) Practically nontoxic

Freshwater fish 2 

### Bluegill sunfish ( Lepomis macrochirus ) Rainbow trout ( Oncorhynchus mykiss ) Fathead minnow ( Pimephales promelas ) Practically non toxic

Freshwater invertebrates Water flea ( Daphnia magna ) Practically non toxic

Estuarine/marine fish Sheepshead minnow ( Cyprinodon variegatus ) Practically non toxic

Estuarine/marine invertebrates Mysid shrimp ( Americamysis bahia ) 

### Quahog clam ( Mercenaria mercenaria ) Slightly toxic

Terrestrial plants Carrot ( Daucus carota subsp. Sativus ) Tomato ( Lycopersicon esculentum var. esculentum ) Onion ( Allium cepa ) No toxicity classification available for plants
Aquatic plants and algae Duckweed ( Lemna gibba) Cyanobacteria ( Anaebaena flos

- aquae )

1 Birds represent surrogates for terrestrial

- phase amphibians and reptiles.
2 Freshwater fish may be surrogates for aquatic

- phase amphibians.

a Data are incomplete pending passerine submission



### 4. 1 . Incident Database Review

A review of the Ecological Incident Information System (EIIS) database for incidents involving primisulfuron methyl was conducted on December 21, 2011

. Sixty

- seven plant incidents are reported in the database (Appendix C ). These plant incidents occurred on agricultural areas,

corn, with possible misuses on s oybean and sugar beet sites since primisulfuron methyl was not

### 10 registered for those uses

, and ranged in certainty from ‘possible’ to ‘probable’ , with one ‘unlikely’ . The magnitude of response varied from 1 to 4 0 00 acres.

Similarly, a search of the Avian Incident Monitoring Syste m (AIMS; http://www.abcbirds.org/abcprograms/policy/toxins/aims/aims/index.cfm ), a database administered by the American Bird Conservancy which contains publicly available data on reported avian incidents involving pesticides. No avian incident s have been recorded for primisulfuron methyl in this database

. Pesticide registrants report certain types of incidents to the Agency as aggregate counts of incidents occurring per product per quarter. Sixty

- nine aggregated plant incidents have been reported to t he Agency associated with primisulfuron methyl since 1998. Similar to the EIIS database, t hey resulted from registered uses (16 reports) and mis uses (53 reports)

.
4. 2 . Ecosystems Potentially at Risk

The ecosystems at risk are often extensive in scope; therefore, it may not be possible to identify specific ecosystems during the development of a nation

- wide ecological risk assessment. However, in general terms, terrestrial ecosystems potentially at risk could include the treated field and immediately adj acent areas that may receive drift or runoff. Areas adjacent to the treated field could include cultivated fields, fencerows and hedgerows, meadows, fallow fields or grasslands, woodlands, riparian habitats and other uncultivated areas.

Aquatic ecosyst ems potentially at risk include water bodies adjacent to, or downstream from, the treated field and could include impounded bodies such as ponds, lakes and reservoirs, or flowing waterways such as streams or rivers. For uses in coastal areas, aquatic habi tat also includes marine ecosystems, including estuaries.

5. Assessment Endpoints

Assessment endpoints represent the actual environmental value that is to be protected, defined by an ecological entity (species, community, or other entity) and its attribute or characteristics (EPA, 1998). For primisulfuron methyl, the ecological entities include the following: birds, mammals, reptiles, amphibians, freshwater fish and invertebrates, estuarine/marine fish and invertebrates, terrestrial plants, ins ects, and aquatic plants and algae. The attributes for each of these entities may include growth, reproduction, and survival

.

### 11 6. Conceptual Model

For a pesticide to pose an ecological risk, it must reach ecological receptors in biologically significant c oncentrations. An exposure pathway is the means by which a pesticide moves in the environment from a source to an ecological receptor. For an ecological pathway to be complete, it must have a source, a release mechanism, an environmental transport medium, a point of exposure for ecological receptors, and a feasible route of exposure.

The conceptual model for primi sulfuron methyl provides a written description (risk hypothesis) and visual representation (conceptual diagram) of the predicted relationships b etween primi sulfuron methyl , potential routes of exposure, and the predicted effects for the assessment endpoint (USEPA 1998b).

Based on the available data, primi sulfuron methyl is water soluble

, stable in neutral to alkaline water, and also stable to pho tolytic degradation. Primi sulfuron methyl is moderately persistent in soil under aerobic and anaerobic conditions though there is uncertainty of persistence in aquatic environments due to a lack of data. It is mobile in soil, is not volatile, and

, g iven its relatively low K ow 

### , is not likely to accumulate in aquatic food webs. With these properties, it appears that primi sulfuron methyl is mobile and has a potential to leach into ground water or move offsite into surface water.

Additionally, in general, SU herbicides are known to be very toxic to sensitive non

- target plants. When used in accordance with the label, primisulfuron methyl may move off the site of application by spray drift and/or runoff. This may result in potential risk to the reproduction in terrestrial non

- target plants inhabiting adjacent or nearb y acreage below the threshold known to cause effects in guideline studies

. 6.1. Risk Hypothesis

For primisulfuron methyl, the following ecological risk hypothesis is being employed for this baseline risk assessment:

Primisulfuron methyl, w hen used in accordance with the label, may result in potential adverse effects upon the survival, growth, and reproduction of non

- target terrestrial and aquatic organisms. Given the degree of persistence of primisulfuron methyl and its degree of mobility, there is a likelihood of exposure to terrestrial and/or aquatic organisms.

6.2. Conceptual Diagram

The conceptual model used to depict the potential ecological risk associated with the use of primisulfuron methyl (the stressor) assumes that as a pesticide, primisulfuron methyl can adversely affect terrestrial and aquatic organisms (the receptors) if environmental concentrations exceed toxic thresholds as a result of application according to the label directions ( Figures 1 , 2 and 3 ). Ecological receptors that may potentially be exposed to primisulfuron methyl include terrestrial and semi

- aquatic wildlife ( e.g. , mammals, birds, terrestrial

- phase amphibians and

### 12 reptiles), terrestrial and semi

- aqua tic plants, and terrestrial invertebrates ( e.g. , honey bees). Additionally, given the mobility of primisulfuron methyl , aquatic organisms ( i.e. , freshwater and estuarine/marine fish and invertebrates, aquatic

- phase amphibians, and aquatic plants) are pote ntial receptors in adjacent water bodies through off

- site transport of primisulfuron methyl from the application site through runoff, erosion, and spray drift.

Figure 1 . Conceptual model for primi sulfuron methyl exposure to aquatic organisms and plants

. Dashed lines indicate route of exposure considered of lower importance for primisulfuron methyl

. 

### Stressor

Source

Receptors

Attribute Change Primisulfuron methyl

Spray drift

Aquatic Animals Eggs Larvae Juveniles / Adults

Individual organisms Reduced survival Reduced growth Reduced reproduction Food chain Reduction in algae Reduction in prey Habitat integrity Reduction in primary productivity Reduced cover Community change Surface water (including direct application ) Runoff

Aquatic Animals Invertebrates Vertebrates 

### Exposure Media

Uptake/gills or integument

Ingestion Ingestion A tmospheric transport

Wet/dry deposition Soil Ground water

Uptake/gills or integument

Aquatic Plants Non

- vascular Vascular Uptake/cell, roots, leaves Riparian plant terrestrial
exposure pathways see

Figure 2

### 13 Figure 2 . Conceptual model for primisulfuron methyl exposure to terrestrial animals and plants

. Dashed lines indicate route of exposure considered of lower importance for primisulfuron methyl

. 

### Stressor

Source

Receptors

Attribute Change Primisulfuron methyl

Direct application Spray drift

Birds / Terrestrial

phase amphibians / reptiles / mammals/ Insects Terrestrial

i nver ts

Individual organisms Reduced survival Reduced growth Reduced reproduction Food chain Reduction in prey Habitat integrity Reduction in primary productivity Reduced cover Community change Terrestrial/riparian plants grasses/forbs, fruit, seeds (trees, shrubs) Runoff

Mammals 

### Exposure Media Soil

Ingestion Ingestion

Ingestion Ingestion Dermal uptake/Ingestion

A tmospheric transport Root uptake Wet/dry

Birds / Amphibians

Ingestio n Groundwater

Irrigation

Water

### 14 

# Stressor

Source

Attribute Change Primisulfuron

- methyl applied to use site

Direct application Spray drift

Terrestrial vertebrates Terrestrial invertebrates

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

related to prey availability Habitat integrity Reduction in primary productivity Reduced cover Community change Modification of PCEs related

to habitat Runoff



# Exposure Media Dew (formed on terrestrial plants) Atmospheric transport



# Receptors Puddles (formed on treated fields)

Ingestion Inhalation Air

Figure 3. Conceptual diagram for drinking water and inhalation exposure pathways and effects of primisulfuron methyl uses on non

- target terrestrial animals. Dashed lines indicate route of exposure considered of lower importance for primisulfuron methyl.



### 7. Analysis Plan

In order to address the risk hypothesis, the potential for adverse effects on the environment will be estimated. The use, environmental fate, and ecological effects of primisulfuron methyl will be characterized and integrated to assess the risks. This wi ll be accomplished using a risk quotient (ratio of exposure concentration to effects concentration) approach. Although risk is

### 15 often defined as the likelihood and magnitude of adverse ecological effects, the risk quotient

based approach does not provide a quantitative estimate of likelihood and/or magnitude of an adverse effect. However, as outlined in the Overview Document (USEPA 2004), the likelihood of effects to individual organisms from particular uses of primisulfuron methyl may be estimated using t he probit dose

- response slope and either the level of concern (discussed below) or the actual calculated risk quotient value.

This analysis plan will be revisited and may be revised depending upon the information submitted by the public in response to t he opening of the Registration Review docket for primisulfuron methyl

.

7.1. Stressors of Concern

The stressor of concern in the assessment will be primisulfuron methyl and degradate CGA

171683

. T he Agency does not routinely include an evaluation of mi xtures of active ingredients, either those mixtures of multiple active ingredients in product formulations or those in the applicator’s tank. In the case of the product formulations of active ingredients (that is, a registered product containing more than one active ingredient), each active ingredient is subject to an individual risk assessment for regulatory decision regarding the active ingredient on a particular use site. If effects data are available for a formulated product containing more than

one a ctive ingredient, the data may be used qualitatively or quantitatively in accordance with the Agency’s Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs document and the Services’ Evaluation Memorandum (USEPA, 2004; Williams and Hogarth, 2004)

.
7.2. Measures of Exposure

Aquatic Exposure

In order to estimate risks of primisulfuron methyl exposures in aquatic environments, exposure modeling will be based on maximum application rates and methods as on the labels

. Measures of exposure are based on aquatic models that predict estimated environmental concentrations (EECs) of primisulfuron methyl . The models used to predict aquatic EECs are the Pesticide Root Zone Model coupled with the Exposure Analysis Modeling Syst em (PRZM/EXAMS). These models are parameterized using relevant reviewed environmental fate data from registrant submissions and the literature. Model input values will be consistent with the most recent version of the input parameter guidance (Version 2. 1; USEPA 2009).

PRZM and EXAMS are simulation models coupled with the linkage program shell: PE5 ( P RZM E XAMS Model Shell), which incorporates the standard scenarios developed by EFED. The models generate daily exposures and calculated 1

- in

- 10 year EECs of primisulfuron methyl and possibly (depending on the outcome of environmental fate studies) toxicologically significant degradation products. PRZM simulates pesticide fate and transpor t as a result of leaching, direct spray drift, runoff and erosion from an agricultural field, and EXAMS estimates environmental fate and transport of pesticides in a surface water body for a 30

- year period. The combined

### 16 model is designed to estimate pesti cide concentrations found in water (standard pond) at the edge of the treated field. As such, it provides high

- end values of the pesticide concentrations that might be found in ecologically sensitive environments following pesticide application. The loca tion of the field is specific to the crop being simulated using site

- specific information on the soils, weather, cropping, and management factors associated with the scenario. The crop/location scenario is intended to represent a high

- end exposure site on which the crop is normally grown. Based on historical rainfall patterns, the receiving water body receives multiple runoff events during the years simulated. Weather and agricultural practices are simulated for 30 years so that the 10

- year exceedance pr obability at the site can be estimated. The simulation is generated using 30 years of meteorological data, encompassing the years from 1961 to 1990. Additional information on these models can be found at: http://www.epa.gov/oppefed1/models/water/index.htm

. The standard scenarios used for ecological pesticide assessments assume application to a 10

- hectare agricultural field that drains into an adjacent 1

- hectare water body that is 2 meters deep (20,000 m 3 

### volume) with no outlet. PRZM/EXAMS is used to estimate screening

- level exposure of aquatic organisms to primi sulfuron methyl . The measure of exposure for aquatic species is the 1

- in

- 10 year return peak or rolling mean concentration. The 1

- in

- 10 year peak is used for estimating acute exposures of direct effects to aquatic organisms. The 1

- in

- 10

- year 60

- day mean is used for assessing chronic exposure to fish and aquatic

- phase amphibians. The 1

- in

- 10

- year 21

- day mean is used for assessing ch ronic exposure to aquatic invertebrates.

Due to the persistence and mobility of primisulfuron methyl and its degradates, an irrigation assessment will be performed to determine environmental exposure from primisulfuron methyl

contaminated groundwater used for irrigation. Irrigation will be assessed with the groundwater model approved for use at the time of the risk assessment.

Terrestrial Exposure

In order to estimate risks of primisulfuron methyl exposures in terrestrial environments, exposure modelin g will be based on maximum application rates and methods as on the labels. Measures of exposure are based on terrestrial models that predict estimated environmental concentrations (EECs) of primisulfuron methyl. The model used to predict terrestrial EECs o n food items is the Terrestrial Residue Exposure model (T

- REX). The model used to derive EECs relevant to terrestrial plants is TerrPlant. These models are parameterized using relevant reviewed data from registrant submissions and the literature. Model i nput values will be consistent with the most recent version of the input parameter guid ance (Version 2.1; USEPA 2009).

Exposure estimates for terrestrial organisms assumed to be in the target area or in an area exposed to off

- site deposition are derived using the T

- REX model. This model incorporates the Kenaga nomograph, as modified by Fletcher et al. (1994), which is bas ed on a large set of field residue data. The upper limit values from the nomograph represent the upper bound of residue values from actual field measurements (Hoerger and Kenaga 1972). The Fletcher et al. (1994) modifications to the Kenaga nomograph are based on measured field residues from 249 published research papers, including information on 118 species of plants, 121 pesticides, and 17

### 17 chemical classes. Based on these data, T

- REX assumes a 35

- day foliar dissipation half

- life in the absence of other data.

In order to determine if more data are necessary, the S creening T ool for I nhalation R isk (STIR) was used to calculate an upper bound estimate of exposure using primi sulfuron methyl ’s vapor pressure and molecular weight for vapor phase exposure as we ll as the maximum application rate and method of application for spray drift. STIR incorporates results from several toxicity studies including acute oral and inhalation rat toxicity endpoints obtained from the “six

- pack” of core studies, which are a seri es of six guideline studies that are submitted to the Registration Division of the Office of Pesticide Programs for technical and formulated products of a pesticide as well as the most sensitive acute oral avian toxicity endpoint. Based on the results of the STIR model, inhalation exposure alone was determined not to be a potential pathway of concern for avian or mammalian species on an acute exposure basis.

Inhalation exposure via spray drift and/or vapor

- phase of the pesticide alone does not appear to be of concern. The analysis of the inhalation route in STIR does not consider that aggregation with other exposure pathways such as dietary, dermal, or drinking water may contribute to a total exposure that has a potential for effects to non

- target anima ls. However, the Agency does consider the relative importance of other routes of exposure in situations where data indicate that pesticide exposures through other routes may be potentially significant contributors to wildlife risk (USEPA, 2004). The risk assessment will discuss the impact of consideration of other routes of exposure that have been identified as potentially important and the degree of certainty associated with screening

- level risk assessment conclusions. Detailed information about STIR,

a s well as the tool, can be found on the EPA’s website
at: http://www.epa.gov/pesticides/science/models_pg.htm#terrestrial

.

The S creening I mbibition P rogram (SIP) was used to calculate an upper bound estimate of exposure using primisulfuron methyl’s solubility, the most sensitive acute and chronic avian and mammalian toxicity endpoints. Drinking water exposure alone was determined not to be a potential pathway of concern for both avian (and surrogates) and mammalian species on an acute and chronic exposure basis. This route of exposure will be considered further in the risk assessment. Detailed information about the SIP v.1.0, as well as the tool, can be found on the EPA’s w ebsite at http://www.epa.gov/pesticides/science/models_pg.htm#terrestrial

. EECs for terrestrial pla nts are derived using TerrPlant. This model uses estimates of pesticides in runoff and in spray drift to calculate EECs. EECs are based upon solubility, application rate and minimum incorporation depth.

The AgDRIFT or AgDISP spray drift model may be used to assess exposures of organis ms to primi sulfuron methyl deposited on terrestrial habitats by spray drift.

### 18 7.3. Measures of Effect

Ecological effects data are used as measures of direct and indirect effects to biological receptors. Effects data are obtained from registrant

- submitted studies or from literature studies identified by the ECOTOX database. When guideline or open literatur e studies are not available, a quantitative structure

- activity relationship (QSAR) model may be used as a surrogate to estimate the effects.

The acute measures of effect used for animals in this assessment are the LD 50 

### , LC 50 

### and EC 50


### . LD stands for "Let hal Dose", and LD 50 

### is the amount of a material, given all at once, that is estimated to cause the death of 50% of the test organisms. LC stands for “Lethal Concentration” and LC 50 

### is the concentration of a chemical that is estimated to kill 50% of the te st organisms. EC stands for “Effective Concentration” and the EC 50 

### is the concentration of a chemical that is estimated to produce a specific effect in 50% of the test organisms. Endpoints for chronic measures of exposure for listed and non

- listed animal s are the NOAEL/NOAEC and NOEC. NOAEL stands for “No Observed

- Adverse

- Effect

- Level” and refers to the highest tested dose of a substance that has been reported to have no harmful (adverse) effects on test organisms. The NOAEC ( i.e. , “No

- Observed

- Adverse

- Effect

- Concentration”) is the highest test concentration at which none of the observed effects were statistically different from the control. For plants, only acute exposures are assessed ( i.e. , EC 25 

### for terrestrial plants and EC 50 

### for aquatic plants); fo r listed plants either the NOAEC or EC 05 

### is used.

Where available, sublethal effects observed in both registrant

- submitted and open literature studies will be evaluated qualitatively. Such effects may include behavioral changes ( e.g. , lethargy and chan ges in coloration). Quantitative assessments of risks, though, are limited to those endpoints that can be directly linked to the Agency’s assessment endpoints of impaired survival, growth and reproduction.

In the absence of taxon

- specific data, t he assessment of risk for direct effects to non

- target organisms makes the assumption that toxicity of primisulfuron methyl to birds is similar to terrestrial

- phase amphibians and reptiles. The same assumption is made for fish and aquatic

phase amphibians.

Table 4 lists the measures of environmental exposure and ecological effects used to assess the potential risks of prim isulfuron methyl to non

- target animals and plants. The methods used to assess the risk are consistent with those outlined in the Overview D ocument (USEPA, 2004).

Table 4

- Measures of Exposure and Effect Used in Assessing Potential Risks Associated with the Proposed Use of Primisulfuron methyl on Corn and KY Bluegrass Grown for Sod
Assessment Endpoint Surrogate Species and Measures of Ecological Effect 1 

### Measures of Exposure

Birds, terrestrial

phase amphibians and reptiles 2 Survival Lowest acute oral LD 50 ( Northern bobwhite quail and mallard duck ) and subacute dietary LC 50 (Northern

bobwhite quail and mallard duck) Upper

- bound residues on food items (foliar) Reproduction and Growth Lowest reproduction NOAEC (duck)

### 19 Table 4

- Measures of Exposure and Effect Used in Assessing Potential Risks Associated with the Proposed Use of Primisulfuron methyl on Corn and KY Bluegrass Grown for Sod
Assessment Endpoint Surrogate Species and Measures of Ecological Effect 1 

### Measures of Exposure

Mammals Survival Laboratory rat acute oral LD 50 Reproduction and Growth Laboratory rat reproduction NOAEC

Freshwater fish and aquatic

- phase amphibians 3 Survival Lowest acute LC 50 (rainbow trout) Peak EEC Reproduction and Growth Lowest reproduction NOAEC (fathead minnow) 60

- day average EEC

Freshwater invertebrates Survival Water flea acute EC 50 Peak EEC Reproduction and Growth Water flea reproduction NOAEC 21

- day average EEC

Estuarine/marine fish Survival Sheepshead minnow acute LC 50 Peak EEC
Reproduction and Growth Sheepshead minnow reproduction NOAEC 60

- day average EEC

Estuarine/marine invertebrates Survival Lowest acute EC 50 /LC 50 (mysid shrimp) Peak EEC

Reproduction and Growth Mysid shrimp reproduction NOAEC 21

- day average EEC

Terrestrial plants 4 Survival and growth Lowest EC 25 for non

- listed plants and corresponding NOAEC (or EC 05 ) for listed plants from seedling emergence (monocot

onion ; dicot

- tomato ) and vegetative vigor

(monocot

- onion; dicot

- carrot ) studies Estimates of drift and runoff
to non

- target areas

Insects Survival (not quantitatively

assessed) Honeybee acute contact LD 50 Maximum application rate

Aquatic plants Survival and growth Lowest EC 50 for non

- listed plants and corresponding NOAEC (or EC 05 ) for listed plants for algal ( cyanobacteria ) and vascular plant (duckweed) Peak EEC

1 The most sensitive species tested within taxonomic groups is used for baseline risk assessments.
2 Birds represent surrogates for amphibians (terrestrial

- phase) and reptiles.
3 Freshwater fish represent surrogates for amphibians (aquatic

- phase).
4 Four species of two families of monocots

- one is corn, six species of at least four dicot families, of which one is soybeans.
5 LD 50 = Lethal dose to 50% of the test population; NOAEC = No observed adverse ef fect concentration; LOAEC = Lowest observed adverse effect concentration; LC 50 = Lethal concentration to 50% of the test population; EC 50 /EC 25 = Effect concentration to 50%/25% of the test population.



### 7.4. Integration of Exposure and Effects

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

- target species. For the assessment of primisulfuron methyl risks, the risk quotient (RQ) method is used to compare exposure and measu red toxicity values. EECs are divided by acute and chronic toxicity values. The resulting RQs are then compared to the

### 20 Agency’s Levels of Concern (LOCs) (USEPA 2004) ( Table 5 ) . These criteria are used to indicate when primisulfuron methyl use, as direct ed on the labels, has the potential to cause adverse direct or indirect effects to non

- target organisms. In addition, incident data from the EIIS will be considered as part of the risk characterization.

Table 5

- Agency Risk Quotient (RQ) Metrics an d Levels of Concern (LOC) Per Risk Class
RISK CLASS RISK DESCRIPTION RQ LOC Aquatic Animals (fish and invertebrates)
Acute Potential for effects to non

- listed animals from acute
exposures Peak EEC/LC 50 1 0.5

Acute Restricted Use Potential for effects to animals from acute exposures Risks may be mitigated through restricted use classification Peak EEC/LC 50 1 0.1

Acute Listed Species Listed species may be potentially affected by acute
exposures Peak EEC/LC 50 1 0.05

Chronic Potential for effects to non

- listed and listed animals from chronic exposures 60

- day EEC/NOAEC (fish) 1 21

- day EEC/NOAEC (invertebrates) Aquatic Plants
Non

- Listed Potential for effects to non

- listed plants from exposures Peak EEC/EC 50 1
Listed Potential for effects to listed plants from exposures Peak EEC/NOAEC or EC 05 2 1

Terrestrial Animals (mammals and birds)
Acute Potential for effects to non

- listed animals from acute
exposures EEC/LC 50 (Dietary) 0.5 EEC/LD 50 (Dose)

Acute Restricted Use Potential for effects to animals from acute exposures Risks may be mitigated through restricted use classification EEC/LC 50 (Dietary) 0.2 EEC/LD 50 (Dose)
Acute Listed Species Listed species may be potentially affected by acute
exposures EEC/LC 50 (Dietary) 0.1 EEC/LD 50 (Dose)
Chronic Potential for effects to non

- listed and listed animals from chronic exposures EEC/NOAEC 1

Terrestrial Invertebrates
Acute Listed Species Listed species may be potentially affected by acute
exposures EEC/LD 50 0.05

Terrestrial and Semi

- Aquatic Plants
Non

- Listed Potential for effects to non

- target, non

- listed plants from
exposures EEC/ EC 25 1

Listed Plant Potential for effects to non

- target, listed plants from
exposures EEC/ NOAEC or EC 05 2 1

1 LC 50 or EC 50 . 2 An EC 05 is used when a NOAEC is not available



### 7.5 . Effects to Aquatic Organisms

The most sensitive of the available aquatic toxicity data from registrant

- submitted studies are provided in Table 6 . Any studies available in ECOTOX will be reviewed for the risk

### 21 assessment. There are no data for shell deposition and no chronic data for estuarine/marine fish and invertebrates , although the lack of toxicity to freshwater organisms suggests these data are not necessary for risk assessment. Based on the available information, primisulfuron methyl is classified as practically nontoxic to freshwater and estuarine/marine fish and freshwater invertebrates and slightly toxic to estuarine/marine invertebrates on an acute exposure basis. Available data indicate both vascular and nonvascular aquatic plants are affected by primisulfuron methyl

. There are no aquatic toxici ty data available for degradate CGA

- 171683.

Table 6

. Most Sensitive Aquatic Toxicity Pr ofile for Primisulfuron Methyl
Taxonomic Group Surrogate Species (Common Name) Endpoint (mg ai/L) Acute Classification Reference (MRID)

Freshwater Fish Oncorhynchus mykiss (rainbow trout) LC 50 =210 Practically nontoxic 41781502
Pimephales promelas ( fathead minnow ) N OAEC= 11 a

-- 41418608

Freshwater Invertebrates Daphnia magna (daphnid shrimp) EC 50 >100 Practically nontoxic 41418605
NOAEC=0.41

-- 41418609
Estuarine/marine Fish Cyprinodon variegatus (sheepshead minnow) LC 50 >100 Practically nontoxic 41418606

Estuarine/marine Invertebrates Mysidopsis bahia (mysid shrimp) EC 50 =16 Slightly toxic 41418607

Vascular plants Lemna gibba (duckweed) EC 50 = 0.0008 NOAEC=0.0004 -- b 40520102

Nonvascular plants Anabaena flos

- aquae (Cyanobacteria) EC 50 =0.098 NOAEC=0.055 -- b 42147902

a No effects were observed at the highest dose tested. The LOAEC is >11 mg a.i./L
b Toxicity categories for plants have not been defined.



### 7.6 . Effects to Terrestrial Organisms

Table 7 summarizes the most sensitive terrestrial toxicity endpoints for primisulfuron methyl

, based on an evaluation of the submitted data. If open literature studies are identified through ECOTOX, they will be reviewed for the risk assessment. Primisulfuron m ethyl is classified as practically nontoxic to terrestrial birds on a subacute dietary exposure basis; acute oral data for passerines is necessary to fully evaluate the risks to all birds including the smaller passerine species exposed primisulfuron methyl via the oral route

. Primisulfuron methyl is classified as practically nontoxic to mammals on an acute oral exposure basis. Primisulfuron methyl is classified as practically nontoxic to honey bees ( Apis mellifera ) on an acute contact exposure basis. No t oxicity category for terrestrial plants is available; however, primisulfuron methyl is quite toxic to terrestrial plants.

There are no terrestrial toxici ty data available for degradate CGA

- 171683.

Table 7

. Most Sensitive Terrestrial Toxicity Profile for Primisulfuron Methyl

Taxonomic

Group Surrogate Species (Common Name) Endpoint Acute Classification/ Chronic effect Reference (MRID)

### 22 Taxonomic

Group Surrogate Species (Common Name) Endpoint Acute Classification/ Chronic effect Reference (MRID)

Birds Anas platyrhynchos (Mallard duck) LD 50 >2150 mg ai/kg

bw Practically nontoxic a 40331251 a

LC 50 >5000 mg ai/kg diet Practically nontoxic 40331252
NOAEC=500 mg ai/kg

diet b -- 40512004

Mammals Rattus norvegicus (Laboratory rat ) LD 50 >50 5 0 mg ai/kg

bw Practically non toxic 00403312

Laboratory rat LOAEL=5000 mg ai/kg

- diet NOAEC=10 00 mg ai/kg

- diet Reduced pup weight 40512009

Terrestrial Invertebrates Apis mellifera (Honey bee) LD 50 > 100 μg ai /bee Practically nontoxic 41364002

Seedling
emergence Monocot: Onion EC 25 =0.0015 lb/A NOAEC=0.00027 lb/A c

-- d 40856505 Dicot: Tomato EC 25 =0.0002 NOAEC=0.0027 c

Vegetative vigor Monocot: Onion EC 25 =0.00057 lb/A NOAEC=0.00045 lb/A

-- d 40856506 Dicot: Carrot EC 25 =0.0002 lb/A NOAEC<0.0001 lb/A c

a D ata are incomplete pending passerine submission
b No effects were observed at the highest dose tested, the LOAEC is >500 mg a.i./kg.

c The NOAEC is unreliable; an EC 05 value will be used as a surrogate; however, the unavailable EC 05 s will be calculated prior to the risk assessment.
d Toxicity categories for plants have not been defined.



### Although avian subacute and mammalian acute endpoints are nondefinitive values, preliminary calculation of RQs (not shown) indicate that the highest dose tested ( e.g. 5000 mg ai/kg

- bw) are sufficiently higher than the EECs that furt her data are not needed at this time.

Deterministic and Probabilistic Assessment Methods

The quantitative assessment of risk will primarily depend on the deterministic point

- estimate (RQ) based approach described in the risk assessment. An effort will be made to further qualitatively describe risk using probabilistic tools that the Agency has developed. These tools have been reviewed by FIFRA Scientific Advisory Panels ( http://www.epa.gov/scipoly/sap /index.htm ) and have been deemed as appropriate means of refining assessments where deterministic approaches have identified risks. Newer tools may be available to assess the routes of exposure ( e.g. TIM and SWAMP models) and will be applied as appropriat e in Registration Review.

7.7

. Endocrine Disruptor Screening Program

### 23 As required under FFDCA section 408(p), EPA has developed the Endocrine Disruptor Screening Program (EDSP) to determine whether certain substances (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an eff ect produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator may designate.” The EDSP employs a two

- tiered approach to making the statutorily required determinations. Tier 1 consists of a battery of 11 screening as says to identify the potential of a chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go through Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal s ystems will proceed to the next stage of the EDSP where EPA will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 testing is designed to identify any adverse endocrine related effects caused by the substance, a nd establish a dose

- response relationship between the dose and the E, A, or T effect.

Between October 2009 and February 2010, EPA issued test orders/data call

- ins for the first group of 67 chemicals, which contains 58 pesticide active ingredients and 9 in ert ingredients. This list of chemicals was selected based on the potential for human exposure through pathways such as food and water, residential activity, and certain post

- application agricultural scenarios. This list should not be construed as a list of known or likely endocrine disruptors.

Primisulfuron methyl is not among the group of 58 pesticide active ingredients on the initial list to be screened under the EDSP. Under FFDCA sec. 408(p) the Agency must screen all pesticide chemicals. Accordingly, EPA anticipates issuing future EDSP test orders/data call

- i ns for all pesticide active ingredients

. For further information on the status of the EDSP, the policies and procedures, the list of 67 chemicals, the test guidelines and the Tier 1 screening battery, please visit our website: http://www.epa.gov/endo/

.
7.8 . Federally

- listed Endangered and Threatened Species Assessment

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), the Agency will evaluate risks to Federally

- listed threatened an d/or endangered (listed) species from registered uses of primisulfuron methyl . This assessment will be conducted i n accordance with the Overview Document (USEPA 2004), provisions of the ESA, and the Services’ Endangered Species Consultation Handbook (USFW S/NMFS, 1998).

The assessment of effects associated with the registration of primisulfuron methyl is based on an action area. The action area is considered to be the area directly or indirectly affected by the federal action, as indicated by the exceedan ce of Agency Levels of Concern (LOCs) used to evaluate direct or indirect effects. The Agency’s approach to defining the action area under the provisions of the Overview Document (USEPA 2004) considers the results of the risk assessment process to establi sh boundaries for that action area with the understanding that exposures below the Agency’s defined LOCs constitute a no

- effect threshold. For the purposes of this assessment, attention will be focused on the footprint of the action ( i.e ., the area where primisulfuron methyl application occurs), plus all areas where offsite transport ( i.e ., spray drift,

### 24 runoff, etc .) may result in potential exposure that exceeds the Agency’s LOCs. Specific

measure s of ecological effect that define the action area for listed species include any direct and indirect effects and/or potential modification of its critical habitat, including reduction in survival, growth, and reproduction as well as the full suite of subl ethal effects available in the effects literature. Therefore, the action area extends to a point where environmental exposures are below any measured lethal or sublethal effect threshold for any biological entity at the whole organism, organ, tissue, and cellular level of organization. In situations where it is not possible to determine the threshold for an observed effect, the action area will initially be assumed to include all counties where primisulfuron methyl is used in the United States.

7.9 . Drin king Water Assessment

A drinking water assessment will be conducted to support future human health dietary risk assessments of primi sulfuron methyl . The drinking water exposure assessment will be conducted for the maximum labeled use in support of the hu man health dietary risk assessment. The drinking water assessment will incorporate model estimates of primisulfuron methyl alone in surface water and ground water including any residues that are determined to be of toxicological concern. Concentrations o f primisulfuron methyl in surface waters will be estimated using PRZM/EXAMS (see description above) but using the Index Reservoir scenario rather than the standard pond used with aquatic exposure assessment.

An Estimated Drinking Water Concentration (EDWC ) of primisulfuron methyl in ground water will be estimated using EFED’s Tier I aquatic model SCIGROW (Screenin g Concentration in Ground Water ). SCIGROW is a regression model used as a screening tool to estimate pesticide concentrations found in ground wa ter used as drinking water. The output of SCIGROW represents the concentrations that might be expected in shallow unconfined aquifers under sandy soils, which is representative of the ground water most vulnerable to pesticide contamination likely to serve as a drinking water source.

The drinking water assessment will also include available surface and groundwater monitoring data with consideration of changes in use patterns that may have occurred. States are encouraged to submit monitoring data for review.

7.10 . Environmental Monitoring Data

Primisulfuron methyl has not been included for analysis in United States Geological Survey’s (USGS) National Water Quality Assessment Program (NAWQA) or in the California Department of Pesticide Regulations (DPR) monitoring program, however other sulfonylurea herbicides have been included for NAWQA analysis and have been detected in surface water and ground water ( e.g. bensulfuron). A prospective groundwater study has been performed for primisulfuron methyl find that it is highly mobile and is potentially persistent in lower soil layers ( MRID 42585001)

. While environmental fate properties and use patterns m a y differ, this indicates the potential for herbicides similar to primisulfuron methyl to be present in surface and ground waters.

### 25 8.0 . Preliminary Identification of Data Gaps

8.1 . Environmental Fate

The studies submitted to fulfill environmental fate data requirements for primisulfuron methyl are not sufficient to conduct an exposure assessment; four data requirements have not been met as stipulated by 40 CFR part 158 Subpart N §158.1300 for all pesticides with use patterns for terrestrial and nonfood applications . These studies will decrease uncertainty in determining the potential exposure to the pe sticide :

**•** Submission of an acceptable aerobic aquatic metabolism (OPPTS guideline # 835.4300) study is necessary to understand the degradation of primisulfuron methyl in oxygen abundant aquatic environments. The guideline stipulates that at least two dif ferent sediment:water systems be submitted that are similar to the potential use sites in the United States. In the absence of this data, the model input for aerobic soil metabolism is doubled to conservatively estimate the model input for aerobic aquatic metabolism.

**•** Submission of an acceptable anaerobic aquatic metabolism (OPPTS guideline # 835.4400) study is necessary to understand the degradation of primisulfuron methyl in
oxygen

- limiting environments. In the absence of this data, the model input for an aerobic soil metabolism is doubled to conservatively estimate the model input for anaerobic aquatic metabolism.

**•** There are currently terrestrial field dissipation studies (OPPTS guideline # 835.6100) under review by the Agency. Until the review is complete, EFED cannot be certain the data are sufficient for risk assessment. This study is necessary to understand the dissipation of primisulfuron methyl in field conditions.

**•** Supplemental to the terrestrial field dissipation studies are the independent laboratory method validation, and environmental chemistry methods used for the field study.

Table 8 identifies studies by MRID that offer data for each guideline requirement, as well as study classifications and whether or not further data are needed in order to s upport risk assessment ( i.e. , whether there is a data gap).

Table 8 . Summary of available environmental fate data for primisulfuron methyl and its degradates

.
Guideline Study Title MRID / ACC No. Classification Data Gap? Comments

835.2120 Hydrolysis 40331261 Acceptable
No This study is acceptable. No hydrolysis observed at pH 7 and 9, long half

- life (>30 days) was observed for pH 5.

40856507 Supplemental The test at pH 5 had unacceptable material balance. At pH 7 and pH 9, the compound was stable.

835.2240 Photodegradation in Water 40331262 Supplemental

No 40856508 Supplemental The compound did not photodegrade in sunlight in pH 5 and pH 9 solutions.

41418611 Acceptable The compound did not photodegrade in sunlight in pH 9 solutions.

835.2410 Photodegradation 40856420 Unacceptable No Parent and degradate not positively identified

### 26 Guideline Study Title MRID / ACC No. Classification Data Gap? Comments

on Soil 40856421 Unacceptable The TLC methodology was not demonstrated to be adequate

41418612 Acceptable Degradation occurred with half lives of 24.2 days and 26.0 days on sunlight

- irradiated and dark control samples respectively indicating that degradation was due to chemical processes other than photolysis.

835.4100 Aerobic Soil Metabolism 40331263 Supplemental

No Major degradates were not identified. Parent compound degraded with a half

- life of 63 days.
40856511 In Review

41418613 Acceptable Study conducted with pyrimidine

- labeled compound with a half life of 30 days. This study satisfies the need for an aerobic soil metabolism study.

835.4200 Anaerobic Soil Metabolism 40331263 Acceptable

No Study conducted with phenyl

- labeled compound with a half life of 89 days. This study satisfies the need for an anaerobic soil metabolism study.

40856511 In Review

41418614 Acceptable Study conducted with phenyl

- labeled compound with a half life of 41 days. This study satisfies the need for an anaerobic soil metabolism study.

835.4300 Aerobic Aquatic Metabolism No Data No Data Yes In the absence of submitted data, it will be conservatively assumed that the aerobic aquatic metabolism half

- life is two times the estimate of the aerobic soil metabolism half

- life . The value of this data is low because the assumption made is sufficiently conservative.

835.4400 Anaerobic Aquatic Metabolism No Data No Data Yes In the absence of submitted data, it will be conservatively assumed that the anaerobic aquatic metabolism half

- life is two times the estimate of the anaerobic soil metabolism half

- life . The value of this da ta is low because the assumption made is sufficiently conservative.

835.1240 Mobility

- Adsorption / Desorption 40331264 Acceptable

No Soil column leaching study. Additional characterization for aged soils is needed. Further mobility on the triazine moiety is needed to characterize the mobility of the parent and major degradates.

40856513 Acceptable This soil column leaching study found 72.5

- 73.7% of radioactivity applied to soil columns in leachate

40856514 Invalid This soil column leaching found greater amounts of primisulfuron methyl at study conclusion than at study initiation.

### 27 Guideline Study Title MRID / ACC No. Classification Data Gap? Comments

41869302 Acceptable This aged column leaching study found the residues of pyrimidine

- labeled primisulfuron methyl to be very mobile.

41869303 Acceptable This aged column leaching study found the residues of phenyl

- labeled primisulfuron methyl to be very mobile.

41869304 Acceptable This aged column leaching study found the residues of phenyl

- labeled primisulfuron methyl to be very mobile.

41869305 Acceptable This aged column leaching study found the residue CGA

- 120844 to be very mobile.

41869306 Acceptable This aged column leaching study found the residue CGA

- 171683 to be very mobile.

41869307 Acceptable This aged column leaching study found the residue CGA

- 177288 to be very mobile.

41869308 Acceptable This aged column leaching study found the residue CGA

- 191429 to be very mobile.

41869309 Acceptable This aged column leaching study found the residue CGA

- 27913 to be very mobile.

835.6100 Terrestrial Field Dissipation 40512015 Supplemental

Yes 1 The s e studies provide data on dissipation of parent primisulfuron methyl but does not address the pattern of formation and decline of degradates 40512016 Supplemental
40512017 Supplemental
40512018 Supplemental
40512019 Supplemental

40856515 Unacceptable Primisulfuron methyl comprised only 51

- 81% of radioactivity at time 0. Also, the analytical method used was nonspecific and did not distinguish residues.

43263203 In Review If these studies do not fulfill the data requirement, field dissipation of of primisulfuron methyl cannot be adequately characterized and laboratory data will be conservatively interpreted for risk characterization
purposes. The value of this data is mode rate. 43263204 In Review
43263205 In Review

43263206 In Review

850.1730 Fish BCF R2072317 Data Waiver No

1 Environmental chemistry methods used to generate data associated with this study must include results of a successful confirmatory method trial by an independent laboratory. Test standards and procedures for independent laboratory validation are availabl e as addenda to the guideline for this test requirement.



### 8.2 . Effects

The available ecological effects data set for primisulfuron methyl and its degradates is considered incomplete

.

There are no data on the effect of primisulfuron methyl on shell deposition or on the chronic effects on reproduction and growth of estuarine/marine species; although the toxicity to freshwater species is two orders of magnitude higher than the estimated EEC suggests that these data with estuarine/marine speci es would not affect risk conclusions

. The value for these data with primisulfuron methyl is low.

### 28 There are no data with primisulfuron methyl for acute oral effects on passerine species; according to 40 CFR 158, a study with a passerine exposed to the TGA I is necessary for risk
assessment to fully evaluate the acute effects to all birds including the smaller passerine species on an acute oral basis

. Although there are no effects observed in the available mallard duck and bobwhite quail studies, studies ha ve shown nestling passeriformes and breeding females to be more sensitive to certain pesticides than adult males and nonbreeding females (Minneau 1996). In addition, the Scientific Advisory Panel (SAP 1996) 1 

### recommends including passerine birds to consider the differential sensitivity associated with age or gender of the test birds, especially altricial nestlings and breeding adults. The value for the passerine acute oral toxicity study with primisulfuron methyl is medium.

Terrestrial plants are typically very sensitive to sulfonylurea urea herbicide exposure. There is evidence 2 

### to suggest plant reproduction may be affected by sulfonylurea herbicides at levels below effects on vegetative growth or visual injury (Fletcher et al ., 1993). Uncertainty regardi ng the potentially greater sensitivity of terrestrial plant reproduction has been discussed extensively in the environmental fate and effects RED assessment for chlorsulfuron (D330621). Therefore, to the extent that terrestrial plant reproduction is more sensitive to primisulfuron methyl than growth endpoints, risks to terrestrial plants may be underestimated in this risk assessment. Additional information on the reproductive toxicity of primisulfuron methyl to terrestrial plants would help address this u ncertainty. The value for the terrestrial plant reproduction study with primisulfuron methyl is high.

Toxicity and risk from primisulfuron methyl degrada te CGA

- 171683 is an area of significant uncertainty. As discussed in the environmental fate section (Section 3.3 ), the major degradate, CGA

- 171683, is persistent and will remain in the soil after the parent has degraded (present at 75% of applied concentration at 12 mo nths and in anaerobic soil reaching 75% of app lied radioactivity at 3 months , yet there are no data on CGA

- 171683 . There is an exposure concern for CGA

- 171683 to affect the reproduction in birds due to the potential mobility and persistence, the Agency is asking for an avian reproduction study with bobwhites and mallards exposed to the degradate CGA

- 171683; the value for the data is high.

For all other taxonomic groups exposed to CGA

- 171683, the value for the degradate data is low since the preliminary assessment
, “degradate toxicity comparison” (Appendix D ) concluded that the predicted toxicity of CGA

- 171683 from the QSAR analysis with a surrogate chemical is near that of parent primisulfuron methyl. Because exposure is too low to trigger the Level of C oncern (LOC), by two orders of magnitude, it is unlikely that additional toxicity data for the degradates will alter the risk conclusions for parent primisulfuron methyl.

1 Scientific Advisory Panel (1996). A s et of Scientific Issues Being Considered by the Agency in Connection with EPA’s Ecological Risk Assessment of Carbofuran Flowable Products and with EPA’s Corn Cluster Ecological Risk Assessment. Review conducted in an open meeting held on May 29

– 31. Page s 37

- 49.
2 Snipes et al. 1992, Bansal et al. 1999; Fletcher et al. 1993, 1995,1996; Bhatti et al. 1995; Al

- Khatib et al. 1992; Boutin et al. 2000; Asghari and Evans 1992

### 29 The available effects studies for primisulfuron methyl and degradate CGA

- 171683 are presented in Tables 9

- 1 2

. The following data gaps are identified below.

**•** Primisulfuron methyl

- OPPTS 850.2100 ; An avian acute oral study with a passerine is necessary for risk assessment. Until the data is available , EFED cannot be certain the data are sufficient for an ecological risk assessment on birds

.

**•** Primisulfuron methyl

- Non

- guideline ; Terrestrial Plant Reproduction Study will be necessary for risk assessment to fully evaluate the effects of primisulfuron methyl to plants at different stages

.

**•** Degradate CGA171683

- OPPTS 850.2300; reproduction toxicity to upland game bird and waterfowls

. Toxicity data on the environmental relevant degradate CGA 171683 of primisulfuron methyl is necessary for risk assessment since CGA171683 is persistent in the en vironment with 75% of the degradate remaining after 12 months

.

TABLE 9 . Available ecological effects data for terrestrial animals exposed to primisulfuron methyl

Guideline Description MRID/ Accession Classification Data Gap? Comments

850.2100 Avian oral toxicity

Upland game bird

and waterfowl 40331250 40331251 Acceptable Acceptable
Yes 1 1 Avian acute oral toxicity data are not available for passerine species. Data are needed to fully evaluate the effects of primisulfuron methyl to all birds including the smaller, passerine, species

. The value for the passerine acute oral data with primisulfuron methyl is high.
2 Avian reproduction toxicity data are not available for
up land game birds; however, no reproduction effects to mallards occurred at the highest level tested and no acute effects to mallards and quails occurred at the highest level test, there are sufficient data to assess the chronic effects on birds. The value f or the quail reproduction data with primisulfuron methyl is low. Avian oral toxicity

– passerines No data

--

850.2200 Avian dietary toxicity 40331252 40331253 Acceptable Acceptable No

850.2300 Avian reproduction 40512003 40512004 Invalid Acceptable Yes 2

850.3020 Honeybee acute contact toxicity 41364002 Acceptable No



### TABLE 1 0 . Available ecological effects data for aquatic animals exposed to primisulfuron methyl

.

### 30 Guideline Description MRID/ Accession Classification Data Gap? Comments

850.1075 Freshwater fish

– Acute toxicity 40331254 40331255 41418603 41418604 41781501 41781502 Invalid Supplemental Supplemental Supplemental

Acceptable Acceptable No 1 Although acute estuarine/marine data for Eastern oyster (shell deposition) and chronic estuarine/marine data for sheepshead minnow and mysid shrimp are unavailable for primisulfuron methyl , the lack of toxicity with other aquatic organisms (e.g., fathead minnow ELS, embryo

larval acute and mysid shrimp
acute ) ; in addition, the lowest aquatic organism value is approximately two orders of magnitude above the EEC that would result in a chronic effect to daphnids, suggest these data are unnecessary for the risk assessment. The value for these estuarine/marine species data with primisulfur on methyl is low. 850.1075 Estuarine/marine fish

– Acute toxicity 40331257 41418606 Invalid Acceptable No

850.1010 Freshwater invertebrates

– Acute toxicity 40331256 41418605 Supplemental Acceptable No

850.1025 850.1035 850.1055 Estuarine/marine invertebrates

– Acute toxicity 40331258 40331259 41364001 41418607 Invalid Supplemental

Acceptable Acceptable Yes 1

850.1300 Freshwater invertebrate

– life cycle test 40512006 41418609 Invalid Acceptable No

850.1350 Estuarine/marine invertebrates

– life cycle test No data

-- Yes 1

850.1400 Freshwater fish

– early life stage test 40512005 41418608 Invalid Supplemental No

850.1400 Estuarine/marine fish

– early life stage test No data

-- Yes 1



### TABLE 1 1

. Available ecological effects data for plants exposed to primisulfuron methyl

.

Guideline Description MRID Classification Data Gap? comments

850.4100 Ter restrial Plant toxicity: Tier I and II seedling emergence 40512011 40856505 Acceptable Acceptable No

850.4150 Ter restrial Plant toxicity: Tier I and II

vegetative vigor 40512010 40856506 Acceptable Acceptable No

850.5400 Aquatic Plant Growth: algae 40520101 42147901 42147902 42147903 Acceptable Acceptable Acceptable Acceptable No

850.4400 Aquatic Plant Growth: vascular plants 40520102 Acceptable No

### 31 TABLE 1 2 . Available ecological effects data for animals and plants exposed to CGA

171683

. Guideline Description MRID Classification Data Gap? comments

850.2300 Avian reproduction No data

-- Yes 1 1 Degradate CGA

- 171683 toxicity data on the effect of reproduction to birds is needed to fully evaluate the effects of the degradate to the environment due to its mobility and persistence

. The value for the data with CGA

- 171683 is high.

850.4100 Terrestrial Plant toxicity: Tier I and/or Tier II seedling

emergence No data

-- Yes 2 2 Primisulfuron methyl is quite toxic to terrestrial plants, it is unlikely risk conclusions would be altered with degradate data. The value for the data is low.

850.1075 Freshwater Fish: acute toxicity No data

--

Yes 3 The QSAR analysis with a surrogate chemical suggests that the toxicity of the degradate is almost the same as that of parent primisulfuron methyl which is two orders of magnitude higher than the EEC to result in an effect. It is likely that the additional data with the degradate would not alter the risk conclusions for parent primisulfuron

m ethyl. The value for the data is low. 850.1400 Freshwater Fish: early life stage test No data

--

850.1010 Freshwater Invertebrate: acute toxicity No data

--

850.1300 Freshwater Invertebrate: life

- cycle
test No data

--

850.5400 Aquatic Plant Growth: algae No data

--

850.4400 Aquatic Plant Growth: vascular plants No data

--



### 8. Other Information Needs

There is specific information that will assist the Agency in refining the ecological risk assessment, including any species

- specific effects determinations. The Agency is very much interested in obtaining the following information: 1. confirmation on the following label information

a. frequency of application, application intervals, and maximum number of applications per season b. geographic li mitations on use 2. use or potential use distribution ( e.g ., acreage and geographical distribution of relevant crops) 3. use history

### 32 4. median and 90 th 

### percentile reported use rates (lbs. a.i./acre) from usage data

– national, state, and county 5. application timing ( date of first application and application intervals) by crop

– national, state, and county 6. sub

- county crop location data 7. directly acquired county

- level usage data (not derived from state level data)

a. maximum reported use rate (lbs. a.i./acre) from usage dat a

– county b. percent crop treated

– county

c. median and 90 th 

### percentile number of applications

– county d. total pounds per year

– county

e. the year the pesticide was last used in the county/sub

- county area f. the years in which the pesticide was applied in the county /sub

- county area 8. state or local use restrictions 9. ecological incidents (non

- target plant damage and avian, fish, reptilian, amphibian and mammalian mortalities) not already reported to the Agency 10. monitoring data

9

. References

Open Literature Citations

Fletcher, J.S., J.E. Nellessen, and T.G. Pfleeger. 1994. Literature review and evaluation of the EPA food

- chain (Kenaga) nomogram, an instrument for estimating pesticide residues on plants. Environ. Tox. Chem. 13:1383

- 1391.

Hoerger, F., and E.E. Kenaga . 1972. Pesticide residues on plants: Correlation of representative data as a basis for estimation of their magnitude in the environment. In F. Coulston and F. Korte, eds ., Environmental Quality and Safety: Chemistry, Toxicology, and Technology, Georg T hieme Publ, Stuttgart, West Germany, pp. 9

- 28.

Nakata, M. 1991. The mode of action of chlorsulfuron in culture cells of tobacco and hamster. J. Pest. Sci. 16:583

- 590

U.S. Fish and Wildlife Service (USFWS) and National Marine Fisheries Service (NMFS). 19 98. Endangered Species Consultation Handbook: Procedures for Conducting Consultation and Conference Activities Under Section 7 of the Endangered Species Act. Final Draft. March 1998.

USEPA. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs. U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Washington DC. January 23, 2004.

U SEPA. 1998. Guidelines for Ecological Risk Assessment. Risk Assessment Forum, Office of Research and Development, Washington, D.C. EPA/630/R

- 95/002F. April 1998. http://cfpub.epa. gov/ncea/cfm/recordisplay.cfm?deid=30759

### 33 Willis, G.H. and L.L. McDowell. 1987. Pesticide Persistence on Foliage in Reviews of Environmental Contamination and Toxicology. 100:23

- 73.

USDA

- NASS (United States Department of Agriculture’s National Agricul tural Statistic Service) Private Pesticide Market Research.

Review of Emergency Exemption Requests from Washington and Idaho for Use of Primisulfuron methyl Herbicide to Control Weeds in Kentucky Bluegrass Grown for Seed (98

- ID

- 09, 98

- WA

- 08), DP barcodes D 243385 through D243388; Anderson, Neil, and Halverson,Alan, 4/08/98.

Scientific Advisory Panel (1996). A set of Scientific Issues Being Considered by the Agency in Connection with EPA’s Ecological Risk Assessment of Carbofuran Flowable Products and with EPA’s Corn Cluster Ecological Risk Assessment. Review conducted in an open meeting held on May 29

– 31. Pages 37

- 49.

Submitted Fate Studies



## 161

- 1 Hydrolysis

MRID Citation Reference

40331261 2072326 2072316= study report Obrist , J. (1987) Hydrolysis of Phenyl

- [Carbon 14]

- CGA

- 136872 in Water: Final Report: Laboratory Project ID: 6015

- 260A. Unpub

- lished study prepared by Hazleton Laboratories America, Inc. 80 p.

40512013 2072325= summary Rhoads, W. (1987) Determination of The H ydrolysis Rate Constants of CGA

136872 Using Pyrimidine ?Carbon 14|

- labeled CGA

- 136872: Laboratory Study Number 1062. Unpublished study prepared by Colorado Analytical Research & Development Corporation. 60 p.

40856507 2072351 2072325= summary Rhoads, W. (1988) Determination of the Hydrolysis Rate Constants of CGA

136872 Using Pyrimidine ?carbon 14|

- Labeled CGA

- 136872: Stu

- dy No. 1062. Unpublished study prepared by Colorado Analytical Research and Development Corp. 66 p.

43263201 Kesterson, A. (1994) Hydrolysis of Phenyl

- (carbon

- 14)

- CGA 136872 at pH, 7 and 9: Lab Project Number: 442. Unpublished study prepared by PTRL East, Inc. 85 p.

43263202 Kesterson, A. (1994) Hydrolysis of Pyrimidinyl

- (carbon

- 14)

- CGA 136872 at pH, 7 and 9: Lab Project Number: 443. Unpublished study prepared by PTRL East, Inc. 85 p.



## 161

- 2 Photodegradation

- water

MRID Citation Reference

### 34 40331262 2072311= summary

2072319= study report Obrist , J. (1987) Photodegradation of Phenyl

- [Carbon 14]

- CGA

- 136872 in Water: Final Report: Laboratory Project ID: 6015

- 260B. Un

- published study prepared by Hazleton Laboratories America, Inc. 128 p.

40512014 See 40856509 Rhoads, W. (1987) Determination of the Aqueous Photolysis Characteristics of CGA

- 136872 Under Natural and Artificial Light using Pyrimidine ?Carbon 14|

- CGA

- 136872: Laboratory Study No. 1060. Unpublished study prepared by Colorado Analytical Research & Deve lopment Corporation. 191 p.

40856508 2072352 2072353

2072325= summary Lawrence, L. (1988) Solution Photolysis of CGA

- 136872 Under Natural Sunlight Conditions: Study No. 211. Unpublished study prepared by Pharmacology & Toxicology Research Laboratory. 94 p.

40856509 2072354 2072355 Rhoads, W. (1988) Determination of the Aqueous Photolysis Characteristics of CGA

- 136872 Under Natural and Artificial Light using Pyrimidine ?Carbon 14|

- CGA

- 136872: Laboratory Study No. 1060. Unpublished study prepared by Colo rado Analytical Research & Development Corporation. 191 p.

40856510 Supplement to 40331262 Obrist, J. (1987) A Supplement to the Report Photodegradation of Phenyl

- ?carbon 14|

- CGA

- 136872 in Water. Unpublished study pre

- pared by Ciba

Geigy Corp. 18 p.

41418611 2072360 2072325= summary Lawrence, B.; Kesterson, B.; Marsh, J.; et al. (1989) Solu

- tion Photolysis of Pyrimidinyl

- ?Carbon 14|CGA

- 136872 in Natural Sunlight at pH 9: Final Report Re

- Issue: Lab Project Number: 286. Unpublished study prepared by Ph armacology and Toxicology Research Laboratory. 82 p.



## 161

- 3 Photodegradation

- soil

MRID Citation Reference

40856420 2072346 2072348 2072325= summary Lawrence, L. (1988) CGA

- 136872: Soil Surface Photolysis of CGA

- 136872 in Natural Sunlight: Laboratory Project No. 223. Unpub

- lished study prepared by Pharmacology & Toxicology Research Laboratory. 58 p.

40856421 2072349 Rhoads, W. (1988) CGA

- 136872: Determination of the Soil Photolysis Characteristics of CGA

- 136872 under Natural and Artificial Light using Pyrimidin ?Carbon 14|

- Labeled CGA

- 136872: Laboratory Study No. 1061. Unpublished study prepared by Colorado Analytical Research and Development Corp. 93 p.

41418612 2072361 2072325= summary Jackson, S.; Kesterson, A.; Lawrence, L. (1989) Soil Surface Photo

- lysis of Pyrimidinyl

- ?Carbon 14|

- CGA

- 136872 in Natural Sunlight: Final Report Re

issue: Lab Project Number: 287. U npublished study prepared by Ciba

- Geigy Corp. 69 p.



## 162

- 1 Aerobic soil metabolism

### 35 MRID Citation Reference

40331263 2072327 2072328

2072315= study report Obrist, J. (1987) Aerobic, Aerobic/Anaerobic, and Sterile Soil Met

- abolism of Phenyl

- [Carbon 14]

- CGA

- 136872: Final Report: Labora

- tory Project ID: 6015

- 262. Unpublished study prepared by Hazle

- ton Laboratories America, Inc. 146 p.

40856511 DER not located Rhoads, W. (1988) Environmental Fate Study for the Aerobic, Aerobic/An aerobic and Sterile Soil Metabolism of Pyrimidine

- ?carbon 14|

- CGA

- 136872: Study No. 1066. Unpublished study pre

- pared by Colorado Analytical Research & Development Corp. 167 p.

40856512 2072327 2072328 Obrist, J. (1987) A Supplement to Aerobic, Aerobic /Anaerobic, and Sterile Soil Metabolism of Phenyl

- ?carbon 14|

- CGA

- 136872. Unpu

- blished study prepared by Ciba

- Geigy Corp. 31 p.

41418613 2072362 2072325= summary 2072326 Olson, G.; Lawrence, L.; Lawrence, M. (1990) Aerobic Metabolism of ?Carbon 14|

- CGA

- 136872 in Sandy Loam Soil: Lab Project Number: 1242: 288. Unpublished study prepared by Pharmacology and Toxi

- cology Research Laboratory. 189 p.

41418613

- B 2072347 Olson, G.; Lawrence, L.; Lawrence, M. (1990) Aerobic Metabolism of ?Carbon 14|

- CGA

- 136872 in Sandy Loam Soil: Lab Project Number: 1242: 288. Unpublished study prepared by Pharmacology and Toxi

- cology Research Laboratory. 189 p.



## 162

- 2 Anaerobic soil metabolism

MRID Citation Reference

40331263 2072311 and 2072325 = summary

2072315= study report Obrist, J. (1987) Aerobic, Aerobic/Anaerobic, and Sterile Soil Met

- abolism of Phenyl

- [Carbon 14]

- CGA

- 136872: Final Report: Labora

- tory Project ID: 6015

- 262. Unpublished study prepared by Hazle

- ton Laboratories America, I nc. 146 p.

40856511 DER not located Rhoads, W. (1988) Environmental Fate Study for the Aerobic, Aerobic/Anaerobic and Sterile Soil Metabolism of Pyrimidine

- ?carbon 14|

- CGA

- 136872: Study No. 1066. Unpublished study pre

- pared by Colorado Analytical Research & Development Corp. 167 p.

40856 512 2072325= summary Obrist, J. (1987) A Supplement to Aerobic, Aerobic/Anaerobic, and Sterile Soil Metabolism of Phenyl

- ?carbon 14|

- CGA

- 136872. Unpu

- blished study prepared by Ciba

- Geigy Corp. 31 p.

41418614 2072364 2072325= summary Olson, G.; Lawrence, L.; Lawrence, M. (1990) Anaerobic Metabolism of ?Carbon 14| CGA

- 136872 in Sandy Loam Soil: Lab Project Num

- ber: 1206: 289. Unpublished study prepared by Pharmacology and Toxicology Research Laboratory. 58 p.

### 36 

## 163

- 1 Leach/adsorp/desorption

MRID Citation Reference

40331264 2072311= summary

2072313= study report Spare, W. (1986) Determination of the Leaching Potential of CGA

- 136872 Using Soil Thin

- layer Chromatography: Laboratory Study No. 1225. Unpublished study prepared by Agrisearch , Inc. 54 p.

40331265 2072329 2072330 2072318= study report Spare, W. (1986) Leaching Characteristics of Parent CGA

- 136872: Laboratory Study No. 1224. Unpublished study prepared by Agri

- search, Inc. 68 p.

40331266 2072330 Saxena, A. (1986) Leaching C haracteristics of CGA

- 136872 Aged in Soil: Laboratory Study No. 6015

- 263. Unpublished study prepared by Hazleton Laboratories America, Inc. 49 p.

40331267 2072311= summary Spare, W. (1986) Determination of Adsorption/Desorption Constants of CGA

136872: Laboratory Study No. 1223. Unpublished study prepared by Agrisearch, Inc. 63 p.

40856513 2072356 2072357 Saxena, A. (1988) Leaching Characteristics of Phenyl

- ?carbon 14|

- CGA

136872 Aged in Soil: Study No. HLA 6015

- 362. Unpublished study prepared by Hazleton Laboratories America, Inc. 77 p.

40856514 2072358 Rhoads, W. (1988) Determination of the Aged Leaching Characteris

- tics of CGA

- 136872 Using Pyrimidine ?carbon 14|

- Labeled CGA

- 136872: Study No. 1065. Unpublished study prepared by Colorado Analytical Research and Development Corp. 69 p.

41869302 2072372 Spare, W. (1991) Leaching Characteristics of Aged ?Pyrimidinyl

- carbon 14|

- CGA

- 136872: Lab Project Numbers: 12189; 40

- 90. Un

- published study prepared by Agrisearch Inc. 102 p.

41869303 2072373 Spare, W. (1991) Leaching Characteristics of Aged ?Pyrimidinyl

- carbon 14|

- CGA

- 136872: Lab Project Numbers: 12188; 39

- 90. Un

- published study prepared by Agrisearch Inc. 104 p.

41869304 2072371 2072374 Spare, W. (1990) Adsorption/Desorption of ?Carbon 14|

- CGA

- 136872: Lab Project Numbers: 12182; 38

- 90. Unpublished study prepared by Agrisearch Inc. 56 p.

41869305 2072375 Spare, W. (1990) Adsorption/Desorption of ?Carbon 14|

- CGA

- 120844: Lab Project Numbers: 12184; 36

- 90. Unpublished study prepared by Agrisearch Inc. 52 p.

41869306 2072323= summary Spare, W. (1990) Adsorption/Desorption of ?Carbon 14|

- CGA

- 171683: Lab Project Numbers: 12183; 37

- 90. Unpublished stud y prepared by Agrisearch Inc. 52 p.

41869307 2072376 Spare, W. (1990) Adsorption/Desorption of ?Carbon 14|

- CGA

- 177288: Lab Project Numbers: 35

- 90; 12185. Unpublished study prepared by Agrisearch Inc. 68 p.

### 37 41869308 2072377 Spare, W. (1991) Adsorption/Desorption of ?Carbon 14|

- CGA

- 191429: Lab Project Numbers: 12186; 34

- 90. Unpublished study prepared by Agrisearch Inc. 64 p.

41869309 2072378 Spare, W. (1990) Adsorption/Desorption of ?Carbon 14|

- CGA

- 27913: Lab Project Number s: 12187; 33

- 90. Unpublished study prepared by Agrisearch Inc. 52 p.

41418620 2072365 Olson, G.; Jensen, M.; Lawrence, L. (1990) Leaching of ?Carbon 14| CGA

136872 under Actual Field Conditions: Lab Project Number: 1203: 249. Unpublished study prepared by Pharmacology & Toxico

- logy Research Laboratory. 293 p.

41418621 2072359 Lawrence, L. (1988) Supplement to Mobility and Dissipation of ?Car

- bon 14| CGA

- 136872 and Major Degradation Products, ?Carbon 14| CGA

- 120844 and ?Carbon 14| CGA

- 171683, under Ac tual Field Condi

- tions: Lab Project Number: 210. Unpublished study prepared by Pharmacology & Toxicology Research Laboratory. 5 p.



## 164

- 1 Terrestrial field dissipation

MRID Citation Reference

40512015 2072333 2072334 Selman, F. (1987) Field Dissipation Study on CGA

- 136872 For Terrestrial Uses on Corn, Missouri: Laboratory Study No. 37402. Unpublished study prepared by Analytical Bio

- Chemistry Laboratories, Inc. 92 p.

40512016 2072335 2072336 Selman F. (1987) Field Dissipation Study on CGA

- 136872 For Terrestrial Uses on Corn, Georgia: Laboratory Study No. 34703. Unpublished study prepared by Analytical Bio

- Chemistry Laboratories, Inc. 89 p.

40512017 2072337 2072338 Van Geluwe

- Barvir, K.; Ros s, J. (1987) CGA

- 136872

-- Terrestrial Field Dissipation Study: York County, Nebraska: Laboratory Project ID ABR

87119. Unpublished study prepared by Ciba

- Geigy Corporation. 70 p.

40512018 2072339 2072340 Van Geluwe

- Barvir, K.; Ross, J. (1987) CGA

- 136872

- - Terrestrial Field Dissipation Study: Washington County, Mississippi: Laboratory Project ID ABR

- 87117. Unpublished study performed by Ciba

- Geigy Corporation. 68 p.

40512019 2072341 2072342 Van Geluwe

- Barvir, K.; Ross, J. (1987) CGa

- 136872

-- Terrestrial F ield Dissipation Study: Columbia County, New York: Laboratory Project ID ABR

87120. Unpublished study performed by Ciba

- Geigy Corporation. 131 p.

40512020 2072337 2072338 National Oceanic and Atmospheric Administration (1986) Climatological Data: Nebraska, East Central Division York AP Station ... Unpublished study. 91 p.

40512021 DER not located National Oceanic and Atmospheric Administration (1986) Climatological Data : Lower Delta Division: Stoneville Experiment Station ... Unpublished s tudy . 32 p.

40856515 2072359 Lawrence, L. (1988) Mobility and Dissipation of ?carbon 14|

- CGA

- 136872 and Major Degradation Products, ?carbon 14|

- CGA

- 120844 and ?carbon 14|

- CGA

- 171683, Under Actual Field Conditions: Study No. 210. Unpublished study prepar ed by Pharmacology & Toxicolo

- gy Research Laboratory. 159 p.

### 38 41418615 2072333 Selman, F. (1987) Supplemental Field Dissipation Study on CGA

- 136872 for Terrestrial Uses on Corn, Missouri. Unpublished study prepared by Ciba

Geigy Corp. 40 p.

41418616 2 072335 Selman, F. (1987) Supplement to Field Dissipation Study on CGA

- 136

- 872 for Terrestrial Uses on Corn, Georgia. Unpublished study prepared by Ciba

Geigy Corp. 51 p.

41418617 2072325= summary Ross, J.; Van Geluwe

- Barvir , K. (1987) Supplement to CGA

- 136872 Terrestrial Field Dissipation Study, York County, Nebraska. Un

- published study prepared by Ciba

- Geigy Corp. 19 p.

41418618 2072339 Van Geluwe

- Barvir, K.; Ross, J. (1987) Supplement to CGA

- 136872 Terrestrial Field Di ssipation Study, Washington County, Missi

- ssippi. Unpublished study prepared by Ciba

- Geigy Corp. 18 p.

41418619 2072341 Van Geluwe

- Barvir, K.; Ross, J. (1987) Supplement to CGA

- 136872 Terrestrial Field Dissipation Study, Columbia County, New York. Unpu blished study prepared by Ciba

- Geigy Corp. 19 p.

43263203 DER not located

Summary Balu, K. (1994 ) Summary of the Terrestrial Field Dissipation Data for Primisulfuron

- Methyl (Beacon): Lab Project Number: ABR

- 93056: 161940. Unpublished study prepared by Ciba

- Geigy Corp. 69 p.

43263204 DER not located Schofield, C. (1992) Soil Dissipation study with Beacon (Primisulfuron

methyl) on Soil Planted to Sweet Corn: Final Report: Lab Project Number: 263

- 89. Unpublished study prepared by Stewart Agricultural Research Services, Inc.; Minnesota Valley Testing Lab s, Inc. 238 p.

43263205 DER not located Schofield, C. (1992) Soil Dissipation Study with Beacon (Primisulfuron

methyl) on Bare Ground: Final Report: Lab Project Number: 256

- 891. Unpublished study prepared by Stewart Agricultural Research Services, Inc.; Minnesota Valley Testing Labs, Inc. 236 p.

43263206 DER not located Lawrence, L. (1994) Leaching of (carbon 14)CGA

- 136872 Under Actual Field Conditions

-- Characterizations, Identification and Quantitation of Degradates: Addendum: Lab Project Number: 249. Unpublished study prepared by PTRL East, Inc. 155 p.



## 164

- 2 Aquatic field dissipation

MRID Citation Reference



## 165

- 1 Confined rotational crop

MRID Citation Reference

40331268 2072332 2072312 =study report Madrid, S. (1987) CGA

- 136872

-- Confined Accumulation Study on Rota

- tion Crops

-- Uptake of Phenyl

- [Carbon 14]

- CGA

- 136872 from a New York Field Plot: Laboratory Study No. ABR

- 87049. Unpublished study prepared by Ciba

-

### 39 Geigy Corp. 66 p.

40321226 2072332 Madri d, S.O. 1986 Distribution and Characterization of Phenyl

- [Carbon 14]

- CGA

- 136872 in corn........

40856422 2072350 Madrid, S. (1988) CGA

- 136872

-- Confined Accumulation Study on Rotation Crops

-- Uptake of Pyrimidinyl

- ?Carbon 14|

- CGA

- 136872 from a New York Field Plot: Laboratory Study No. ABR

- 88058. Unpublished study prepared by Ciba

- Geigy Corp. 41 p.



## 165

- 5

2072317= study report

not a DER Bioconcentration in Fish



## 166

- 1 Groundwater Monitoring

41804101 2072322 Blasland & B ouck, Eng. (1991) A Small

- Scale Prospective Groundwater Monitoring Study for Primisulfuron

- Methyl (Beacon): Part A: Investigation to Select a ... Site; Protocol No. 17

- 91/A: Lab Project Number: 365.18. Unpublished study. 174 p.

42654101 2072322 Hatfield, M.; Hiscock, A. (1993) A Small

- scale Prospective Ground

- water Monitoring Study for Primisulfuron

- Methyl (Beacon) (CGA

- 136872): Site Assessment Report: Lab Project Number: 17

- 91 PART B: 365.18 PART B: CIG

- NC

- 010

- 2. Unpublished study prepared by Bl asland & Bouck. 21 p.

42128701 2072322= summary Hatfield, M.; Masters, T. (1991) A Small

- Scale Prospective Ground

- Water Monitering Study for Primisulfuron

- Methyl (Beacon): Lab Project Number: 365.18. Unpublished study prepared by Blasland and Bouck Engin eers and Alta Analytical Labs. 55 p.

42040101 2072322 Selman, F. (1991) Responses to the EPA Review of Ciba

- Geigy Protoc

- ol No. 17

- 91 for Small

- Scale Prospective Ground

- Water Monitering Study for Primisulfuron

- Methyl (Beacon): Lab Project Number: ABR

- 91 068. Unpublished study prepared by Ciba

- Geigy. 80 p.

42285201 2072322 Hatfield, M. (1992) A Small

- scale Prospective Groundwater Monitoring Study for Primusulfuron

- Methyl (Beacon) (CGA

- 136872): Lab Project Number: 17

- 91 B: Unpublished study prepared by Bl asland & Bouck, Egn. and Alta Analytical Labs. 28 p.

42407301 2072322 Hatfield, M. (1992) A Small

- Scale Prospective Ground

- Water Monitoring Study for Primisulfuron

- methyl (Beacon) (CGA

- 136872): Third Progress Report: Lab Project Number: 17

- 91 B: 11092793 A. Unpublished study prepared by Blasland & Bouck, Egn., PC in assoc. with Alta Analytical Labs. 38 p.

41418622 2072366 Chang, H.; Bicking, M. (1990) Assessment of CGA

- 136872 75WG Leach

- ing Potential Small Scale Prospective Groundwater Monitoring Study (Beacon Study): Lab Project Number: TCT 4/88

- CGA.1: TCT 9/ 89

- CGA.1: TX

- 88

-

### 40 2223. Unpublished study prepared by Twin City Testing Corp. 454 p.

42585002 2072322 Bethem, R.; Cornacchia, J. (199 2) Prospective Ground Water Monitoring Study for Primisulfuron

- Methyl (Beacon): Fourth Progress Report: Lab Project Number: CIGNC01C

- 2: 17

- 91 PART C. Unpublished study prepared by Alta Analytical Laboratory. 287 p.

Also a letter from K.S. Stumpf is inclu ded in this DER



## 201

- 1 Droplet size spectrum

MRID Citation Reference

41657902 2072367 2072368 Bookbinder, M. (1990) Droplet Size Spectrum of Beacon 75 WG Herbi

cide Sprays

-- Results of Wind Tunnel Testing of Aerial and Air

- blast Application Nozzles: Lab Project Number: 31889. Unpub

- lished study prepared by Orius Associates Inc., in association with New Mexico State Univ. 126 p.

43766502 DER not located Hewitt, A. (1995) Spray Drift Task Force: Atomization Droplet Size Spectra for Selective Active Ingredients: Lab Project Number: A92/004. Unpublished study prepared by SpraySearch

- Daratech Pty. Ltd. and Spray Drift Task Force. 175 p.

40331226

- A 2072350 Huber, M. (1987) CGA

- 136872

-- Nature of the Residue in Corn

-- Metabo

lism: Laboratory Project ID: ABR

- 87082. Unpublished compilation prepared by Ciba

- Geigy Corp. 151 p.



## 202

- 1 Drift field evaluation

MRID Citation Reference

41657903 2072367 2072369 Bookbinder, M. (1990) Field Spray Drift Evaluation of CGA

- 136872: (Beacon 75 WG Primisulfuron

- Methyl Herbicide) Applied to Corn By Aerial Equipment in Pennsylvania, 1989: Lab Project Number: 32089. Unpublished study prepared by Orius Associates Inc ., and Others. 222 p.

41657904 2072367 2072370 Bookbinder, M. (1990) Field Spray Drift Evaluation of CGA

- 136872: Beacon 75 WG Primisulfuron

- Methyl Herbicide) Applied to Corn by Aerial Equipment in Illinois, 1989: Lab Project Number: 31989. Unpublished study prepared by Orius Associates Inc., and Others 202 p.

No MRID 2072320 Protocol Review for spraydrift evaluation



# Non Guideline Selections

### 41 40512012 DER not located Balu, K. (1988) Support Document on the Groundwater Assessment of CGA

- 136872. Unpublished study prepared by Ciba

- Geigy Corporation. 42 p.

40856416 DER not located Williams, L. (1988) CGA

- 136872

-- Storage Stability in Soil Stability of Residues under Freezer Storage Conditions for Two Years: Laboratory Project ID ABR

- 88096. Unpublished study prepared by Ciba

- Geigy Corp. 25 p.

40856418 DER not located Williams, R. (1 987) Analytical Method for the Determination of CGA

171683 in Soil by Gas Chromatography: Laboratory Project ID AG

- 521. Unpublished study prepared by Ciba

- Geigy Corp. 26 p.

41418610 2072326 2072322 Nixon, W. (1990) Response to EPA Review Dated 12/21/89 o f Environ

mental Fate Studies Submitted to Support the Registration of Beacon Herbicide: Lab Project Number: ABR

- 90020. Unpublished study prepared by Ciba

- Geigy Corp. 122 p.

- Repeated under numerous Guidelines

41835701 DER not located Bicking, M. (1991) Assessment of CGA

- 136872 75WG Leaching Potential Small Scale Prospective Groundwater monitoring Study: Final Re

- port Addendum: Lab Project Number: 4/88

- CGA.1: 9/89

- CGA.1: TCT

- 003

- 88

- CGA.1

- BEA. Unpublished study prepared by Twin City Testing Corp. 19 p.

42585001 2072322 Hatfield, M.; Hiscock , A. (1992) A Small

- scale Prospective Ground

- water Monitoring Study for Primisulfuron

- Methyl (Beacon) (CGA

- 136872): Interim Report: Lab Project Number: 365.18 PART B: CIG

- NC

- 010

- 2: 17

- 91 PART B. Unpublished study prepared by Blasland & Bouck Engineers, P.C . and Alta Analytical Laboratory. 120 p.

42654100 Report

DER not located Ciba

- Geigy (1993) Submission of environmental fate data ( investiga

- tion of vandalism at groundwater study site ) for registration of Beacon Herbicide. Transmittal of 1 study.

42654101 2072322 Hatfield, M.; Hiscock, A. (1993) A Small

- scale Prospective Ground

- water Monitoring Study for Primisulfuron

- Methyl (Beacon) (CGA

- 136872): Site Assessment Report: Lab Project Number: 17

- 91 PART B: 365.18 PART B: CIG

- NC

- 010

- 2. Unpublished s tudy prepared by Blasland & Bouck. 21 p.

43263207 DER not located

Registrant modeling Coody, P. (1994) Prediction of CGA

- 136872 Dissipation and Leaching Using PRZM: Comparison to Lysimeter and Ground Water study Results: Lab Project Number: 833. Unpubli shed study prepared by PTRL East, Inc. 62 p.

43263208 Registrant response

DER not located Balu , K. (1994) Response to EPA'S 11/93 Review of Progress Reports Submitted in Connection with the Small

- Scale Prospective Ground

- Water Monitoring Study of Beacon Herbicide in Indiana: Lab Project Number: ARB

- 94016: 161940. Unpublished study prepared by Ciba

- Geigy Corp. 52 p.

43263209 DER not located Hiscock, A. (1994) A Small

- Scale Prospective Ground

- Water Monitoring Study for Primisulfuron

- methyl (Beacon) (CCGA

- 136872): Amended Final Report: Lab Project Number: 17

- 91: 365.18: CIGNCOIC

- 2. Unpublished study prepared by Ciba

- Geigy Corp.; Blasland & Bouck Engineers, P.C.; A&L Midwest Labs; Alta Analytical Lab, Inc.; Enseco

- Rmal Lab. 731 p.

43263210 Registrant Williams, W.; Cheplick, J. (1994) PRZM

- 2 Simulations of Primisulfuron

-

### 42 modeling exercise methyl (Beaco n) in LaGrange County, Indiana: Final Report: Lab Project Number: 242.11: 221

- 94. Unpublished study prepared by Waterborne Environmental, Inc. 53 p.

43263211 DER not located

Registrant assessment Williams, W.; Hahn, A. (1992) The Potential for Primisulfu ron

- Methyl (Beacon) to Leach to Ground Water in New York State: Final Report: Lab Project Number: 92AG013. Unpublished study prepared by Clendenin Consulting & Remediation Group. 79 p.

42040102 2072322 

### Bethem, R. (1991) Determination of Primisulfuron

- met hyl and Its Metabolites in Water and Soil by High Performance Liquid Chroma

- tography/Mass Spectrometry: Lab Project Number: CIGNCO1C

- 3. Un

- published study prepared by Alta Analytical Lab. 73 p.

40512019 B 2072343 2072344 

### Analytical methods used in field dissipation study

40512019

- C 2072345 2072346 

### Storage Stability for Field dissipation study

41869301 2072371 to 2072377 Phelps, W. (1991) Summary of Additional Environmental Fate Studies Required by EPA on CGA

- 136872 (Primisulfuron

- methyl): Lab Pro

- ject No: ABR

- 91029. Unpublished study prepared by Ciba

- Geigy Corp. 15 p. 

### Submitted Effects Studies



## 71

- 1 Avian Single Dose Oral Toxicity

MRID Citation Reference

40331250 2072382 Fletcher, D. (1985) Acute Oral Toxicity Study with CGA

- 136872 Tech

nical in Bobwhite Quail: [Final Report]: Laboratory Study No. 85 QD 55. Unpublished study prepared by Bio

- Life Associates, Ltd. 32 p.

40331251 2072383 Fletcher, D. (1985) Acute Oral Toxi city Study with CGA

- 136872 Tech

nical in Mallard Ducks: [Final Report]: Laboratory Study BLAL No. 85 DD 31. Unpublished study prepared by Bio

- Life Associ

- ates, Ltd. 32 p.



## 71

- 2 Avian Dietary Toxicity

MRID Citation Reference

40331252 2072384 Fletcher, D. (1985) 8

- day Dietary LC50 Study with CGA

- 136872 Tech

nical in Mallard Ducklings: Laboratory Study BLAL No. 85 DC 55. Unpublished study prepared by Bio

- Life Associates, Ltd. 44 p.

40331253 2072385 Fletcher, D. (1985) 8

- day Dietary LC50 Study with CGA

- 136872 Tech

nical in Bobwhite Quail: Laboratory Study BLAL No. 85 QC 54. Unpublished study prepared by Bio

- Life Associates, Ltd. 44 p.

### 43 

## 71

- 4 Avian Reproduction

MRID Citation Reference

40512003 2072392 Fletcher, D. (1987) Toxicity and Reproduction Study with CGA

- 136872 Technical in bobwhite Quail: Laboratory Study No. 86 QR 18. Unpublished study prepared by Bio

- Life Associates, Ltd. 214 p.

40512004 2072393 Fletcher, D. (1987) Toxicity and Reproduction Study with CGA

- 136872 Technical in Mallard Ducks: Laboratory Project ID 86 DR 17. Unpublished study prepared by Bio

- Life Associates, Ltd. 199 p.

41418602 See 2072417

memo Fletcher, D. (1987) Supplemental to T oxicity and Reproduction Study with CGA

- 136872 Technical in Bobwhite Quail: Lab Project Number: 81QR2: 81QR3: 81QR5. Unpublished study prepared by Bio

- Life Associates, Ltd. 25 p.



## 72

- 1 Acute Toxicity to Freshwater Fish

MRID Citation Reference

40331254 2072386 Surprenant, D. (1986) Acute Toxicity of CGA

- 136872 to Rainbow Trout (Salmo gairdneri): Laboratory Study No. BW

- 86

- 2

- 1946. Unpub

- lished study prepared by Springborn Bionomics, Inc. 23 p.

40331255 2072387 Surprenant , D. (1986) Acute Toxicity of CGA

- 136872 to Bluegill (Lepomis macrochirus): Laboratory Study No. BW

- 86

- 2

- 1944. Un

- published study prepared by Springborn Bionomics, Inc. 24 p.

41418603 2072403 Lelievre, M. (1990) Acute Toxicity to Bluegill Sunfish (Lepom is ma

crochirus) under Static Conditions: CGA

- 136872 Amended Final Report: Lab Project Number: 90

- 1

- 3186. Unpublished study pre

- pared by Springborn laboratories, Inc. 42 p.

41418604 2072404 Lelievre, M. (1990) Acute Toxicity to Rainbow Trout (Oncorhync us mykiss) under Static Conditions: CGA

- 136872: Lab Project Number: 90

- 2

- 3238: 1781.1189.6223.103. Unpublished study prepared by Springborn Laboratories, Inc. 41 p.

41781501 2072408 Lelievre, M. (1991) Acute Toxicity to Bluegill Sunfish (Lepomis

- Macroc hirus) Under Static Conditions: CGA

- 136872: Lab Project Number: 91

- 1

- 3632. Unpublished study prepared by Springborn Laboratories, Inc. 51 p.

41781502 2072409 Lelievre, M. (1991) Acute Toxicity to Rainbow Trout (Oncorhynchus Mykiss) Under Static Condition s: CGA

- 136872: Lab Project Number: 91

- 1

- 3643. Unpublished study prepared by Springborn Labora

- tories, Inc. 55 p.

### 44 

## 72

- 2 Acute Toxicity to Freshwater Invertebrates

MRID Citation Reference

40331256 2072388 Surprenant , D. (1986) Acute Toxicity of CGA

- 136872 to Daphnids (Daphnia magna): Laboratory Study No. BW

- 86

- 2

- 1949. Unpublished study prepared by Springborn Bionomics, Inc. 23 p.

41418605 2072405 Lelievre, M. (1990) Acute Toxicity Test to Daphnids (Daphnia magna)

u nder Static Conditions: CGA

- 136872 Amended Final Report: Lab Project Number: 90

- 1

- 3185: 1781.1189.6225.110. Unpublished stu

- dy prepared by Springborn Laboratories, Inc. 45 p.



## 72

- 3 Acute Toxicity to Estuarine/Marine Organisms

MRID Citation Reference

40331257 2072389 Surprenant, D. (1986) Acute Toxicity of CGA

- 136872 to Sheepshead Minnow (Cyrinodon variegatus): Laboratory Study No. BW

- 86

- 2

- 1947. Unpublished study prepared by Springborn Bionomics, Inc. 24 p.

40331258 2072390 Surprenant, D. (1987) Acute Toxicity of CGA

- 136872 to Embryos

- lar

- vae of the Quahog Clam (Mercenaria mercenaria): Laboratory Study No. BW

87

- 5

- 2371. Unpublished study prepared by Springborn Bio

- nomics, Inc. 26 p.

40331259 2072391 Surprenant, D. (1986) Acute Toxicity of CGA

- 136872 to Mysid Shrimp (Mysidopsis bahia): Laboratory Study No. BW

- 86

- 2

- 1950. Unpub

- lished study prepared by Springborn Bionomics, Inc. 24 p.

41364001 Supplement to 40331258 Surprenant, D. (1990) Supplement to Acute Toxicity of CGA

- 136872 to Embryos

- larvae of the Quahog Clam (Mercenaria mercenaria): Study No. 1781.0187.6134.514. Unpublished compilation prepared by Ciba

- Geigy Corp., Agricultural Div. and Springborn Labora

- tories, Inc. 10 p.

41418606 2072406 Lelievre, M. (1990) Acute Toxicity to Sheepshed Minnow (Cyprinodon variegatus) under Static Conditions: CGA

- 136872 Amended Final Report: Lab Project Number: 90

- 1

- 3187: 1781.1189.6220.500. Un

- published study prepared by Springborn Laboratories, Inc. 43 p.

41418607 2072407 L elievre, M. (1990) Acute Toxicity to Mysid Shrimp (Mysidopsis bahia) under Static Conditions: CGA

- 136872: Final Report: Lab Project No. 90

- 3

- 3256: 1781.1189.6221.510. Unpublished study prepared by Springborn Laboratories, Inc. 38 p.



## 72

- 4 Fish Early Life Stage/Aquatic Invertebrate Life Cycle Study

MRID Citation Reference

40512005 2072394 Sugatt, R. (1987) Early Life Stage Test of CGA

- 136872 with Fathead

### 45 Minnows (pimephales promelas): Laboratory Study No. 1086. Unpublished study performed by Envirosystems, Inc. 68 p.

40512006 2072395 Sugatt, R. (1987) Chronic Toxicity Test of CGA

- 136872 with Daphnia Magna: Laboratory Study No. CGA

- DM

- 2051

- A. Unpublished study prepared by Envirosystems, Inc. 55 p.

41418608 DER not located

referenced in 207 2419 as supplemental Ward, T.; Boeri, R. (1990) Early Life

- Stage Toxicity of CGA

- 136872 to the Fathead Minnow, Pimephales Promelas: Lab Project Number: 8917

- CG. Unpublished study prepared by EnviroSystems Division/ Resource Analysts, Inc. 32 p.

41418609 DER not located

referenced in 2072435 as Core Boeri, R.; Ward, T. (1990) Chronic Toxicity of CGA

- 136872 to the Daphnid, Daphnia magna: Lab Project Number: 8918

- CG. Unpub

- lished study prepared by EnviroSystems Div./Resource Analysts, Inc. 34 p.



## 122

- 1 Seed Germination/Seedline Emergence and Vegetable Vigor

MRID Citation Reference

40512010 2072396 Canez , V. (1987) Nontarget Phytotoxicity Study: Vegetative Vigor Tier 1: Laboratory Study No. PAL 23

- TX0451. Unpublished study prepared by Pan Agricultural Labs, Inc. 39 p.

40512011 2072397 Canez, V. (1987) CGA

- 136872: Nontarget Phytotoxicity Study: Seed Germ ination/Seedling Emergence Tier 1: Laboratory Study No. PAL 23

- TX0449. Unpublished study prepared by Pan Agricultural Labs, Inc. 55 p.



## 123

- 1 Seed germination/seedling emergence and vegitative vigor

MRID Citation Reference

40856505 2072400 Canez, V. (1988) Nontarget Phytotoxicity Test Seed Germination/

- Seedling Emergence Tier 2: CGA

- 136872: Study No. LR87

- 34B. Un

published study prepared by Pan

- Agricultural Laboratories, Inc. 269 p.

40856506 2072401 Canez , V. (1988) Nontarget Phytotoxicity Test Vegetative Vigor Tier 2: CGA

- 136872: Study No. LR87

- 34A. Unpublished study prepared by Pan

Agricultural Laboratories, Inc. 207 p.



## 123

- 2 Aquatic plant growth

### 46 MRID Citation Reference

40520101 2072398 Hughes, J. (1986) The Toxicity of CGA

- 136872, Lot No.... to Selenastrum capricornutum: Laboratory Project ID 0267

- 31

- 1100

- 1. Unpublished study prepared by Malcolm Pirnie, Inc. 32 p.

40520102 2072399 Hughes, J. (1987) The Toxicity of CGA

- 136872, Lot No... to Lemna gibba: Laboratory Project ID 0267

- 31

- 1100

- 2. Unpublished study prepared by Malcolm Pirnie, Inc. 30 p.

42147901 2072410 Hughes, J. (1989) The Toxicity of CGA

- 136872 Technical to Seletonema

c ostatum: Lab Project Number: T1P909002. Unpublished study prepared by Ciba

- Geigy Corp. 36 p.

42147902 2072411 Hughes, J. (1989) The Toxicity of CGA

- 136872 Technical to Anaebaena flos

- aquae: Lab Project Number: 0267

- 46

- 1100

- 1. Unpublished study prepared b y Malcolm Pirnie, Inc. 36 p.

42147903 2072412 Hughes, J. (1989) The Toxicity of CGA

- 136872 Technical to Navicula pelliculosa: Lab Project Number: 0267

- 46

- 1100

- 2. Unpublished study prepared by Ciba

- Geigy Corp. 34 p.



## 141

- 1 Honey bee acute contact

MRID Citation Reference

41364002 2072402 Hoxter, K. (1989) CGA

- 136872 Technical: An Acute Toxicity Study with the Honeybee: Lab Study No. 108

- 306. Unpublished study prepared by Wildlife International Ltd. 14 p.

### 47 Appendix A. Justification for Special Study

Guideline Number: none Study Titles: Special Study for Non

- Target Plant Reproductive Toxicity Rationale for Requiring the Data As stated in the Problem Formulation, investigations/studies have indicated a small percentage of the label application rate of low dose high potency herbicides such as sulfonylureas (e.g. primisulfuron ) may impact the reproduction of non

- target terrestria l plants. However, there are no available data on adverse reproductive impacts to terrestrial plants from primisulfuron residues due to spray drift. Terrestrial plant reproductive toxicity data would help to screen for potential plant risks associated wi th primisulfuron use. Plants form the basis of most habitats and contribute significantly to overall environmental quality. T he loss of plant reproductive output could potentially have an adverse effect on animals, both invertebrates and vertebrates, as ma ny are dependent on plant reproduction for a food source and for habitat quality and structure. A solid understanding of the potential risks to plants is therefore essential for sound environmental management. A study protocol must be submitted for review and approved by the Agency prior to initiation of the study. Practical Utility of the Data How will the data be used? The data will be used to estimate potential reproductive risks to non

- target terrestrial plants, including the likelihood of potential risks to endangered species, either by direct effects or by indirect effects, and to reduce uncertainties associated with the current ecological risk assessment. By refining the assessment, the Agency will be able to determine whether current labeling is appropriate and whether further mitigation is necessary. In the absence of this data, risks to terrestrial plants will b e presumed.

How could the data impact the Agency’s future decision

- making? These data, once submitted, should allow the Agency to characterize the risk posed to plant reproductive processes from primisulfuron in terrestrial ecosystems. Primary producers ( i.e. plants) provide food and habitat vital to ecological processes. Therefore, a solid understanding of the potential risks to non

- target plants is essential in order to assess the environmental risks the use of primisulfuron may pose. If the data indicate that primisulfuron poses significant risks to these non

- target plant species, the Agency may explore additional decision options to minimize the risks to these species. The lack of these data will limit the flexibility the Agency and registrants have in complying with the Endangered Species Act and could result in use restrictions for primisulfuron which may otherwise be avoided, or which are unnecessarily severe.

### 48 Appendix B. Proposed Metabolic Pathway

### 49 Appendix C. Incident Reports 

## EIIS Pesticide Summary Report: General Information



# Primisulfuron

- methyl (128973)

Incident # Date County State Certainty Legal. Formul. Appl. Method Total Magnitude



### PLANTS Agricultural area
I009550

- 001 11/15/1999 NE 3 RU N/R N/R UNKNOWN

I013554

- 053 6/26/2002 Ford KS 3 UN DF Broadcast 65 acres


### Corn
I014597

- 036 Dunn ND 2 RU WDG Spray 150 acres

I007796

- 009 7/1/1997 BROWN SD 3 RU DF Spray 180 ACRES

I009573

- 023 6/16/1999 KNOX IN 3 RU DF Broadcast ALL

I009573

- 038 6/16/1999 SEWARD KS 3 RU DF Broadcast 40 ACRES

I009573

- 030 6/22/1999 IDA IA 3 MA DF Broadcast 80 ACRES

I009573

- 037 6/22/1999 UNION KY 3 RU DF Broadcast ALL

I009573

- 029 6/22/1999 BUENA VISTA IA 3 MA DF Broadcast 10 ACRES

I009573

- 022 6/22/1999 KNOX IN 3 RU DF N/R ALL

I009573

- 017 7/1/1999 GRANT WI 3 MA DF Spray 49% OF 135 ACRES

I009573

- 012 7/1/1999 GRUNDY IA 3 MA DF Broadcast 50% OF 80 ACRES

Wednesday, December 21, Certainty Code: 0=Unrelated, 1=Unlikely, 2=Possible, 3=Probable, 4=Highly Probable. Page 1 of 5 Legality Code: RU=Registered Use, M=Misuse, MA=Misuse (Accidental), MI=Misuse (Intentional), U=Unknown.

### 50 Incident # Date County State Certainty Legal. Formul. Appl. Method Total Magnitude

I009573

- 020 7/2/1999 CALHOUN IA 3 MA DF Broadcast 50% OF 20 ACRES

I009573

- 021 7/26/1999 KANE IL 2 RU DF Broadcast 50% OF 39 ACRES

I016814

- 001 6/25/2005 Daviess IL 1 RU WDG Spray 10

- 30 acres of corn 

### Corn, field

I013554

- 024 7/1/2002 KEYA PAHA NE 3 M DF Broadcast 188 acres


### N/R
I009573

- 006 7/1/1999 SCOTT IL 3 MA DF Broadcast 68% OF 110 ACRES

I010837

- 074 6/19/2000 MONTGOMERY IN 3 RU DF Broadcast 57%

I010837

- 034 6/20/2000 MOORE TX 3 UN DF AIR; BROADCAST ALL

I010837

- 039 6/20/2000 JACKSON IN 3 RU DF Broadcast ALL

I010837

- 037 6/21/2000 OCHILTREE TX 3 UN DF Broadcast ABOUT 630 ACRES

I010837

- 071 6/21/2000 ADAMS NE 3 RU DF Broadcast ALL

I010837

- 036 6/21/2000 SHERMAN TX 3 UN DF Broadcast ALL

I010837

- 031 6/27/2000 DOUGLAS SD 3 RU DF Broadcast ALL

I010837

- 030 6/27/2000 DOUGLAS SD 3 UN DF N/R ALL

I010837

- 042 6/30/2000 DANE WI 3 UN DF Broadcast 1 ACRE

I010837

- 035 7/12/2000 OCHILTREE TX 3 UN DF Broadcast ALL

I010837

- 070 7/15/2000 SWIFT MN 3 UN DF N/R ALL

Wednesday, December 21, Certainty Code: 0=Unrelated, 1=Unlikely, 2=Possible, 3=Probable, 4=Highly Probable. Page 2 of 5 Legality Code: RU=Registered Use, M=Misuse, MA=Misuse (Accidental), MI=Misuse (Intentional), U=Unknown.

### 51 Incident # Date County State Certainty Legal. Formul. Appl. Method Total Magnitude

I010837

- 068 7/26/2000 STEELE MN 3 MA DF Broadcast 80 ACRES

I013554

- 041 11/2/2001 Olmsted MN 3 UN DF Broadcast 40 acres

I013554

- 042 11/16/2001 Floyd IA 3 M DF Broadcast 110 acres

I013554

- 055 6/17/2002 Rawlins KS 3 UN DF Broadcast 122 acres

I013554

- 043 6/18/2002 Huron MI 2 UN DF Broadcast 120 acres

I013554

- 054 6/27/2002 Ford KS 3 UN DF Broadcast 65 acres

I013554

- 046 7/1/2002 Douglas SD 3 M DF Broadcast 68 acres

I013554

- 051 7/3/2002 Redwood MN 3 M DF Broadcast 112 acres
I013554

- 045 7/8/2002 Saginaw MI 3 UN DF Broadcast 36 acres

I013554

- 044 7/10/2002 Republic KS 3 UN DF Broadcast 40 acres

I013554

- 049 7/19/2002 Mower MN 3 UN DF Broadcast 30 acres

I013554

- 048 7/22/2002 Chippewa WI 3 M DF Broadcast 65 acres

I013554

- 050 7/23/2002 Monona IA 3 M DF Broadcast 480 acres

I013554

- 047 11/27/2002 Peoria IL 3 M DF Broadcast 160 acres

I016790

- 007 9/20/2005 Cortland NY 2 UN SC Spray Unknown 

### Soybean

I010837

- 003 12/7/1999 FLOYD TX 3 RU DF GROUND ALL

I010837

- 046 5/24/2000 MC PHERSON KS 3 UN DF BAND 585 ACRES

I010837

- 060 6/6/2000 MONROE MO 3 RU DF Broadcast 160 ACRES

I010837

- 057 6/9/2000 WABAUNSEE KS 3 RU DF Broadcast ALL

Wednesday, December 21, Certainty Code: 0=Unrelated, 1=Unlikely, 2=Possible, 3=Probable, 4=Highly Probable. Page 3 of 5 Legality Code: RU=Registered Use, M=Misuse, MA=Misuse (Accidental), MI=Misuse (Intentional), U=Unknown.

### 52 Incident # Date County State Certainty Legal. Formul. Appl. Method Total Magnitude

I010837

- 041 6/14/2000 SCOTT IL 3 RU DF Broadcast ALL

I010837

- 052 6/14/2000 RICE KS 3 UN DF Broadcast ALL

I010837

- 025 6/19/2000 PIKE IL 3 RU DF Broadcast ALL

I010837

- 053 6/20/2000 SCOTT IL 3 RU DF Broadcast 60 ACRES

I010837

- 027 6/21/2000 MONTGOMERY IN 3 RU DF Broadcast ABOUT 4000 ACRES

I010837

- 022 6/23/2000 MACOUPIN IL 3 RU DF BAND ABOUT 80 ACRES

I010837

- 049 6/29/2000 WOODSON KS 3 RU DF Broadcast ALL

I010837

- 065 7/5/2000 EDWARDS KS 3 RU DF Broadcast ALL

I010837

- 064 7/5/2000 HENRY IL 3 UN DF Broadcast ALL

I010837

- 023 7/6/2000 KNOX NE 3 MA DF Broadcast ABOUT 20 ACRES

I010837

- 038 7/6/2000 MONTGOMERY IN 3 RU DF Broadcast APPROX. 700 ACRES

I010837

- 054 7/7/2000 RICE KS 3 RU DF Broadcast ALL

I010837

- 056 7/10/2000 TIPPECANOE IN 3 RU DF Broadcast 65 ACRES OUT OF 75

I010837

- 028 7/11/2000 SPENCER IN 3 RU DF Broadcast ABOUT 64 ACRES

I010837

- 026 7/11/2000 PIKE IL 3 RU DF Broadcast ALL

I010837

- 047 7/28/2000 YELLOW MEDICINE MN 3 RU DF Broadcast ALL

I014597

- 044 5/22/2003 Franklin KS 3 M WDG Spray 50 acres

Wednesday, December 21, Certainty Code: 0=Unrelated, 1=Unlikely, 2=Possible, 3=Probable, 4=Highly Probable. Page 4 of 5 Legality Code: RU=Registered Use, M=Misuse, MA=Misuse (Accidental), MI=Misuse (Intentional), U=Unknown.

### 53 Incident # Date County State Certainty Legal. Formul. Appl. Method Total Magnitude



### Soybeans
I014597

- 035 5/26/2003 Van Buren MI 3 M WDG Spray 300 acres 

### Sugar beet

I007796

- 001 8/21/1998 LAKE MI 2 UN N/R ALL 70 ACRES 

### Sugar beets
I014597

- 037 4/18/2003 Huron MI 3 M WDG Spray 43 acres

### 54 Appendix D. Degradate Toxicity Comparison

The following analysis has been conducted to determine the value of further laboratory toxicity data on the primisulfuron

- methyl degradate CGA171683, or 2

- amino

- 4,6

- bis(difluoromethoxy)pyrimidine. The approach used combines quantitative structure

- activity relationship (QSAR) analysis (ECOSAR model v1.00) with toxicity information from a surrogate chemical. A screening

- level total toxic residue (TTR) aquatic exposure analysis (GENEEC 2.0) was then conducted, to determine if exposures were in the range where effects due to CGA171683 were expected, based on the estimated toxicity. These results were compared to determine if it is likely that exposure to CGA171683 will approach levels of concern (LOC).

It is conc luded that exposures to parent plus CGA171683 are nearly two orders of magnitude below the lowest effects level and thus it is unlikely that aquatic EEC from applications of primsulfuron methyl will reach levels triggering LOCs, based on predicted toxicity . The value of further laboratory toxicity data on aquatic organisms is therefore low. For the purposes of risk assessment the TTR exposure approach will be used to assess risk from applications of primsulfuron methyl in lieu of additional toxicity data for CGA 171683. The following sections describe this analysis in more detail.

No toxicity data is available for CGA171683. However, the FOOTPRINT database http://sitem.herts.ac.uk/aeru/footprint/en/index.htm ) gives toxicity endpo ints for the non

fluorinated analog AEF092944 (INJV0290), which is a degradate of numerous other sulfonylurea herbicides, including bensulfuron, foramsulfuron, and mesosulfuron. Table D 1 presents the aquatic toxicity data given in FOOTPRINT for the analog . Note that EPA has not reviewed the data in FOOTPRINT for validity and thus there is some uncertainty associated with this analysis. Acute toxicity endpoints for the analog place it in the slightly toxic (LC50 10

- 100 ppm) to practically non

- toxic (LC50 > 100 ppm) categories. The structures of both chemicals are given in Table D3

. Surrogate Toxicity Data

The structures of CGA171683 and its analog (AEF092944) were entered into the ECOSAR v.1.0 model as SMILES strings. The results are shown below . The analog was classified by ECOSAR as a neutral organic chemical (baseline toxicity model) and as an aniline (aromatic amine). CGA171683 was classified as a neutral organic, an aromatic amine, and as a halo ether. Predicted endpoints for the analog were compared to the endpoints given in FOOTPRINT. Table D 1 shows the best matches between reported and predicted toxicity for the analog. The best match for the fish acute toxicity test was given by the aromatic amine QSAR. The other endpoints (algae and daphn id acute and chronic) were best matched by the baseline neutral organic QSAR. The agreement is considered to be good, as endpoints were matched to within better than a factor of 5. QSAR Analysis for Analog

Table D 1. Toxicity Data for Analog Chemical And QSAR Analysis for Analog and CGA171683 endpoint INJV0290/AEF092944 (FOOTPRINT data) INJV0290/AEF092944 (ECOSAR) CGA171683 (ECOSAR) Fish 96

- h LC50 97 mg/L 78 mg/L (a.a.) 48.9 mg/L (a.a.)

### 55 (rainbow trout) Fish Chronic No data 0.38 mg/L (a.a.) ChV 0.17 mg/L (a.a.) ChV Algae 72h EC50 120 mg/L (P. subcapitata) 131 mg/L (n.o.) 69.7 mg/L (n.o.)

Lemna 7

- d EC50 > 100 mg/L No prediction No prediction Daphnia 48

- h EC50 > 100 mg/L 469 mg/L (n.o.) 185 mg/L (n.o.) Daphnid Chronic 24 mg/L (21

- d NOEC) 36 mg/L (n.o.)ChV 16 mg/L (n.o.) ChV a.a. = aromatic amine ECOSAR class n.o. = neutral organic ECOSAR class ChV = ECOSAR chronic toxicity value



### Table D 1 also gives the predicted toxicity of CGA171683, from the same QSAR class that best matched the analog (aromatic amine for fish and neutral organic for daphnia and algae). For acute endpoints, the predictions place CGA171683 in either the slightly toxic or practically non

toxic category. Overall, the endpoints for CGA171683 are predicted to be abou t half of those for the analog (i.e., CGA171683 is predicted to be about twice as toxic). QSAR Analysis of CGA171683

To place the toxicity predictions in context, a screening

- level aquatic exposure analysis (GENEEC model) was performed. The GENEEC model was run with the parent stable to all degradation processes, to account for exposure to any degradates. This approach has been widely used in EFED and has been referred to as the total toxic residue (TTR) approach. Table D 2 gives the input parameters. Screening Exposure Analysis

Table D 2. Total Toxic Residue Aquatic Exposure analysis for Primisulfuron

- methyl and Degradates Input parameter Value Reference Maximum Application rate 0.036 lb/A Problem formulation, DP394823, 01/12/12 Number of applications One (1) Average Koc, mL/g o.c. 66 (avg of 74.5, 57.4, 66.3) Solubility 70 ppm Application type Aerial, fine spray, 24.1 % drift Conservative assumption Degradation processes All stable Conservative assumption to account for any degradates No

- spray zone Zero feet Conservative assumptions Incorporation depth Zero inches



### The GENEEC run ( below ) returns an acute exposure of approximately 2 ppb (0.002 ppm) for all exposure averaging times.

The toxicity predictions for CGA171683 indicate that it is more toxic to fish than the parent (LC50 = 210 ppm and NOAEC = 11 ppm); less toxic to algae (parent EC50 = 0.098 ppm); about the same for daphnia acute toxicity (parent EC50 > 100 ppm); and less toxic to daphnia on a chronic basis (parent NOAEC 0.41 ppm). All parent data were taken from the Problem Formulation date 01/12/12, DP394823). Because the predicted toxicity of CGA171683 is near that of parent primisulfuron

- methyl, exposures to either chemical will result in similar risk conclusions at a given ex posure. Interpretation

### 56 ECOSAR makes no prediction for aquatic vascular plants (Lemna), however the analog AEF092944 (EC50 > 100 ppm) is less toxic than parent primisulfuron (EC50 = 0.0008 ppm). If the pattern predicted by QSAR analysis holds, CGA171683 should also be l ess toxic than its parent for Lemna.

The exposure analysis indicates a maximum exposure of about 2 ppb (0.002 ppm) for TTR of primisulfuron

- methyl. The one

- year exposure for CGA171683 is expected to be lower than this. However, due to the high producti on (75%) of CGA171683 in environmental fate studies, and its apparent stability, there may be some accumulation above 2 ppb over time in the farm pond modeled by GENEEC, thus the EEC would be somewhat higher than 2 ppb.

Comparison of the predicted exposur e (0.002 ppm) to the lowest toxicity endpoint predicted for CGA171683 (0.17 ppm ChV for chronic effects to fish) indicates that the exposure is too low to trigger the LOC, by almost two orders of magnitude (i.e. 85x). Even accounting for uncertainty in th e exposure and toxicity predictions, it is considered unlikely that additional laboratory toxicity data for CGA171683 will change the likely risk conclusions for parent primisulfuron

methyl. The value of such data is therefore considered low, and risks fr om CGA171683 may be analyzed as part of a TTR approach using toxicity data for the parent, or QSAR estimates as appropriate.

The toxicity data for the analog compound, AEF092944, were retrieved from the on

- line database FOOTPRINT. The data have not been reviewed by EPA, thus the data quality is unknown. The results are used as given. Uncertainties

Uncertainties for the QSAR analyses are given in Appendix B. The warning for halogenated aromatic amines is not expected to apply to CGA171683, because it d oes not have halogen atoms on its aromatic ring. The predictions for the analog AEF092944 are considered to be good (within a factor of 5).

The exposure analysis for primisulfuron

- methyl is considered to be conservative, because it does not account for degradation processes, thus maximizing exposure to any degradates formed by maximizing parent exposure. GENEEC does not account for accumulation over the 30

- year model run in a typical PRZM

- EXAMS run, however the low exposure in the one

- year GENEEC run i ndicates that exposure to CGA171683 would likely also be low. This uncertainty can be resolved in the risk assessment using Tier 2 aquatic exposure analysis (PRZM

- EXAMS).

### 57 Table D3. Structures of CGA171683 and its Analog, AEF092944 (INJV0290)

AEF092944

CGA171683

### 58 ECOSAR runs for CGA171683 and its analog (AEF092944/INJV0290)

SMILES : Nc1nc(OC(F)F)cc(OC(F)F)n1 CHEM : CGA171683 2

- amino

- 4,6

- bis(dif1uoromethoxy)pyrimidine CAS Num: ChemID1: ChemID2: ChemID3: MOL FOR: C6 H5 F4 N3 O2 MOL WT : 227.12 Log Kow: 1.67 (KowWin estimate) Melt Pt: Wat Sol: 1189 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

------------------------------ Anilines (Aromatic Amines) Halo Ethers Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ====== ========== Anilines (Aromatic Amines) : Fish 96

- hr LC50 48.934 Anilin es (Aromatic Amines) : Fish 14

- day LC50 55.664 Anilines (Aromatic Amines) : Daphnid 48

- hr LC50 2.505 Anilines (Aromatic Amines) : Green Algae 96

- hr EC50 11.486 Anilines (Aromatic Amines) : Fi sh ChV 0.171 Anilines (Aromatic Amines) : Daphnid ChV 0.042 Anilines (Aromatic Amines) : Green Algae ChV 7.220

Halo Ethers : Fish 96

- hr LC50 100.859 Halo Ethers : Daphnid 48

- hr LC50 24.315 Halo Ethers : Fish ChV 5.406 ! Halo Ethers : Daphnid ChV 1.845 !

=========================== ================== ======== ====== ========== Neutral Organic SAR : Fish 96

- hr LC50 334.633 (Baseline Toxicity) : Daphnid 48

- hr LC50 185.480 : Green Algae 96

- hr EC50 69.758 : Fish ChV 32.001 : Daphnid ChV 16.152 : Green Algae ChV 23.758

Note: * = asterisk designates: Chemical may not be soluble enough to measure this predicted effect.

Note: ! = exclamation designates: The toxicity value was determined from a predicted SAR using establishe d acute

- to

- chronic ratios and ECOSAR regression techniques which are documented in the supporting Technical Reference Manual. When possible, this toxicity value should be considered in a weight of evidence approach.

Anilines (Aromatic Amin es):

-------------------------- For Fish Acute Toxicity Values: 2,3,5,6

- Tetrachloroaniline is 19 times more toxic than predicted by this SAR. Tetrabromoaniline may be more toxic than predicted by this SAR as well.

For Daphnid and Green Algae Toxicity Values: Tetrachloro

- and tetrabrom

aniline may be 20 times toxic than predicted by this SAR.

N

- Substituted anilines are less toxic than predicted by these SARs; for these compounds, Neutral Organic SARs are used.

ECOSAR v1.00 SAR Limitations:

### 59 ---------------------------- Maximum LogKow: >7.8 (Fish 96

- hr LC50, Daphnid 48

- h LC50) Maximum LogKow: >3.7 (Fish 14

- day LC50) Maximum LogKow: >4 (Green Algae 96

- hr EC50 and ChV) Maximum LogKow: >4.3 (Fish ChV) Maximum LogKow: >2.4 (Daphnid ChV) Maximum Mo l Wt: 1000

Halo Ethers :

------------ For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical is greater than 5.0, or if the compound is solid and the LC50 exceeds the water solubility by 10X, no effects at saturation are predicted f or these endpoints.

For Green Algae Acute Toxicity Values: If the log Kow of the chemical is greater than 6.4, or if the compound is solid and the EC50 exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

For All Chronic Toxicity Values: If the log Kow of the chemical is greater than 8.0, or if the compound is solid and the ChV exceeds the water solubility by 10X, no effects at saturation are predicted for these endpoints.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: 5.0 (LC50) Maximum LogKow: 6.4 (EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

Baseline Toxicity SAR Limitations:

--------------------------------- Maximum LogKow: 5.0 (Fish 96

- hr LC50; Daphnid LC50) Max imum LogKow: 6.4 (Green Algae EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000

SMILES : n1c(N)nc(OC)cc1OC CHEM : AEF092944 CAS Num: 036315

- 01

- 2 ChemID1: ChemID2: ChemID3: MOL FOR: C6 H9 N3 O2 MOL WT : 155.16 Log Kow: 0.95 (KowWin estimate)
Me lt Pt: Wat Sol: 1.108E+004 mg/L (WskowWin estimate)

ECOSAR v1.00 Class(es) Found

------------------------------ Anilines (Aromatic Amines) Predicted ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ======

========== Anilines (Aromatic Amines) : Fish 96

- hr LC50 78.845 Anilines (Aromatic Am ines) : Fish 14

- day LC50 225.619 Anilines (Aromatic Amines) : Daphnid 48

- hr LC50 2.376

### 60 Anilines (Aromatic Amines) : Green Algae 96

- hr EC50 9.172 Anilines (Aromatic Amines) : Fish ChV 0.380 Anilines (Aromatic Amines) : Daphnid ChV 0.050 Anilines (Aromatic Amines) : Green Algae ChV 6.078

=========================== ================== ======== ======

== ======== Neutral Organic SAR : Fish 96

- hr LC50 922.143 (Baseline Toxicity) : Daphnid 48

- hr LC50 468.756 : Green Algae 96

- hr EC50 131.427 : Fish ChV 89.591 : Daphnid ChV 35.968 : Green Algae ChV 39.276

Note: * = asterisk designates: Chemica l may not be soluble enough to measure this predicted effect.

Anilines (Aromatic Amines):

-------------------------- For Fish Acute Toxicity Values: 2,3,5,6

- Tetrachloroaniline is 19 times more toxic than predicted by this SAR. Tetrabromoaniline may be more toxic than predicted by this SAR as well.

For Daphnid and Green Algae Toxicity Values: Tetrachloro

- and tetrabrom

aniline may be 20 times toxic than predicted by this SAR.

N

- Substituted anilines are less toxic than predicted by these SARs; for these compounds, Neutral Organic SARs are used.

ECOSAR v1.00 SAR Limitations:

---------------------------- Maximum LogKow: >7.8 (Fish 96

- hr LC50, Daphnid 48

- h LC50) Maximum LogKow: >3.7 (Fish 14

- day LC50) Maximum LogKow: >4 (Green Algae 96

- hr EC50 and ChV) Maximum LogKow: >4.3 (Fish ChV) Maximum LogKow: >2.4 (Daphnid ChV) Maximum Mol Wt: 1000

Baseline Toxicity SAR Limitations:

--------------------------------- Maximum LogKow: 5.0 (Fish 96

- hr LC50; Daphnid LC50) Maximum LogKow: 6.4 (Green Algae EC50) Maximum LogKow: 8.0 (ChV) Maximum Mol Wt: 1000



### Screening Aquatic exposure analysis for parent primisulfuron

- methyl

RUN No. 1 FOR primisulfuronmet ON any * INPUT VALU ES *

--------------------------------------------------------------------

RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO

- SPRAY INCORP

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN)

-------------------------------------------------------------------- .036( .036) 1 1 66.0 70.0 AERL_A( 24.1) .0 .0

### 61 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)

--------------------------------------------------------- ----------- METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED

(FIELD) RAIN/RUNOFF (POND) (POND

- EFF) (POND) (POND)

-------------------------------------------------------------------- .00 2 N/A .00

- .00 .00 .00

GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001

-------------------------------------------------------------------- PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 D AY GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC

-------------------------------------------------------------------- 2.21 2.21 2.20 2.19 2.18