2 Several data gaps have been identified in association with a review of registrant

- submitted studies to fulfill guideline requirements

. Submission of data to eliminate data gaps would reduce uncertainties in the exposure assessment. Data gaps have been assigned either a low or high potential t o add value to the Registration Review risk assessment . While still considered data gaps according to 40 CFR Part 158, low potential studies are unlikely to change risk determinations because alternate methods and weight of evidence may possibly be used i n the absence of data. High potential studies would enable the Agency to better characterize potential risks by eliminating exposure uncertainties that cannot be accounted for us ing alternate methods or weight of evidence.

Data from the following guideline studies are considered to have high potential to add value to the ecological risk assessment for prometon :

Guideline 835.4300

– Aerobic Aquatic Metabolism : Data for aerobic aquatic metabolism are required under 40 CFR Part 158. Given that the 200 8 RED (DP 335306) identified a risk concern for aquatic organisms, fulfilling this data requirement has a high potential to add value to the Registration Review ecological risk assessment.

Guideline 835.4 4 00

– A na erobic Aquatic Metabolism : Data for a na erobic aquatic metabolism are required under 40 CFR Part 158. Given that the 200 8 RED (DP 335306) identified a risk concern for aquatic organisms, fulfilling this data requirement has a high potential t o add value to the Registration Review ecological risk assessment.

Guideline 850.1075

– Fish Acute Toxicity, fathead minnow or Guideline 850.1400

– Fish Early Life Stage Toxicity Test , rainbow trout : The chronic, early life stage endpoint of 19.7 mg/L for freshwater fish (fathead minnow; MRIDs 41810902, 42318202) is approximately equal to the most sensitive acute endpoint of 19.6 mg/L for freshwater fish (rainbow trout; MRID 41609108). This discrepancy is probably due to the different species used in the tests ( i.e.

, fathead minnow in the chronic test and rainbow trout in the acute test). Additional data

– either an acute toxicity test with fathead minnow or a chronic test with rainbow trout

– are recommended and considered to have a high potential to add value to the Registration Review risk assessment because the data will allow the Agency to evaluate risk to freshwater fish species as well as generate an acute to chronic ratio (ACR) for evaluating risk to estuarine/marine fish
spec ies from chronic exposure

.

Guideline 850.2100

– Avian O ral T oxicity, passerine species: A cute oral toxicity data for a passerine species a re required under the new 40 CFR Part 158. No studies have been submitted for this data requirement. Given that t he 200 8 RED (DP 335306) identified a risk concern for birds from acute and chronic exposure, fulfilling this data requirement has a high potential to add value to the Registration Review ecological risk assessment as the generated data will allow us to be pr otective of passerine species.

Guideline 850.4400

– Aquatic Plant Toxicity Test Using Lemna spp.: Data for an aquatic vascular species ( Lemna spp.) are required under 40 CFR Part 158. In previous risk assessments,3 an ECOTOX open literature study (E081431) was referenced for characterizing the toxicity of prometon to aquatic vascular plants ( i.e.

, Lemna spp.). However, this study has been classified as qualitative for use in the Registration Review ecological risk assessment because of the lack of experimental details ( e.g. , replication, test concentrations) . Given that the 200 8 RED (DP 335306) identified a risk concern for aquatic vascular plants, fulfilling this data requirement has a high potential to add value to the Regist ration Review risk a ssessment.

Guideline 850.4500

– Algal Toxicity & Guideline 850.4550

– Cyanobacteria ( Anabaena flos

aqua ) Toxicity: Data for aquatic non

- vascular plant species are required under 40 CFR Part 158. No studies have been submitted for a freshwater diatom ( e.g

. , Navicula pelliculosa ), a marine diatom ( e.g. , Skeletonema costatum ), or a cyanobacterium (e.g., Anabaena flos

- aqua ). In previous risk assessments, an ECOTOX open literature study (E009211) was referenced for characterizing the toxicity of prometon to marine algae. However, this study has been classified as qualitative for use in the Registration Review ecological risk a ssessment because of the lack of experimental details ( e.g. , replication, test concentrations) . Given that the 200 8 RED (DP 335306) identified a risk concern for aquatic non

- vascular plants, fulfilling this data requirement has a high potential to add val ue to the Registration Review risk assessment.4 

## REGISTRATION REVIEW

PROBLEM FORMULATION

Prometon

CAS Number 1610

- 18

- 0

US EPA PC CODE 080804

Prepared by:
Robin Sternberg, Ph.D., Wildlife Biologist Stephen Wente, Ph.D., Biologist Environmental Risk Branch I

Reviewed by: Faruque Khan, Ph.D., Senior Fate Scientist Sujatha Sankula, Ph.D., Lead Biologist Environmental Risk Branch 1 Rueben Baris, M.S., Environmental Scientist Environmental Risk Branch 4 Frank Farruggia, Ph.D., Biologist Environmental Risk Branch 3 Environmental Fate and Effects Division U. S. Environmental Protection Agency Office of Pesticide Programs Environmental Fate and Effects Division Environmental Risk Branch I 1200 Pennsylvania Ave., NW Mail Code 7507P Washington, DC 20460 N

N N OCH 3

N N CH 3

CH 3 H 3 C

CH 35 

### Contents

1 Introduction

................................ ................................ ................................ ............................. 6

2 Previous Assessments

................................ ................................ ................................ ............. 6
3 Overview of Prometon Use

................................ ................................ ................................ ..... 7

4 Environmental Fate Summary

................................ ................................ ................................ 8

5 Ecological Effects Summary

................................ ................................ ................................ . 10

5.1 Parent: Prometon

................................ ................................ ................................ ............ 10
5.2 Prometon Degradates

................................ ................................ ................................ ..... 14

5.2.1 ECOSAR

- Predicted vs. Observed Toxicity Endpoints for Parent Prometon

......... 15

5.2.2 GS

- 11526

................................ ................................ ................................ ................ 15
5.2.3 GS

- 14626 and GS

- 17794

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

5.2. 4 GS

- 12853 and GS

- 17791

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

5.2.5 Summary of Degradate Toxicity

................................ ................................ ............. 17
5.3 Review of Incident Databases

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

6 Risk Hypothesis

................................ ................................ ................................ .................... 18

7 Exposure Pathways of Concern

................................ ................................ ............................ 18

8 Analysis Plan

................................ ................................ ................................ ........................ 19

8.1 Stressors of Concern

................................ ................................ ................................ ....... 19
8.2 Meas ures of Exposure

................................ ................................ ................................ .... 19

8.3 Measures of Effect

................................ ................................ ................................ ......... 20

8.4 Integration of Exposure and Effects

................................ ................................ ............... 20
8.5 Drinking Water Assessment

................................ ................................ ........................... 20

8. 6 Endangered Species Assessments

................................ ................................ .................. 21

8.7 Endocrine Disruptor Screening Program

................................ ................................ ....... 21

9 Data Gaps

................................ ................................ ................................ .............................. 22
9.1 Environmental Fate Data

................................ ................................ ................................ 22
9.2 Ecological Effects Data

................................ ................................ ................................ .. 24
10 References

................................ ................................ ................................ ............................. 29

11 Bibliography of Cited MRIDs

................................ ................................ .............................. 29 Appendix A: SIP (v 1.0) Inputs and Results

................................ ................................ ................. 366 

### 1 Introduction

T he purpose of this problem formulation is to provide an understanding of the environmental fate and ecological effects of the registered uses of prometon in support Registration Review. Prometon is a non

- selective triazine herbicide labeled for pre

- and po st

- emergence applications
to sites that require total control of vegetation ( i.e. , annual and perennial grasses and broadleaf weeds) resulting in bare ground for one and two years after a single application

. There are no agricultural uses for prometon. N on

- agricultural uses of prometon include weed control as a spot treatment around buildings, storage areas, fences, pumps, machinery, fuel tanks, recreational areas, guard rails, airports, military installations, highway medians, pipelines, railroads, lumb eryards, rights

- of

- way, and industrial sites (such as transformers, vaults, buried cable closures) 1

. The 2008 Reregistration Eligibility Decision (RED) for prometon specified that all residential use of prometon was to be cancelled. On January 2, 2012 the Agency published in the Federal Register (FR Vol. 78, No.1) a notice of receipt of requests for an amendment to delete all residential uses of prometon on registered labels. The mechanism of action of prometon involves inhibition of photosynthesis via disruption of CO 2 fixation and production of intermediary energy components ( e.g. , ATP and NADPH 2 ) leading to plant death.



### 2 Previous Assessments

An ecological risk assessment for registered uses was conducted as part of prometon’s 2008 RED (DP 335306). The RED did not require any additional environmental fate or ecological effects studies.

The RED assessment identified risk to:

• birds and mammals from acute and chronic exposure. Risk to both taxa from acute
exposure via spray drift wa s estimated to drop below levels of concern approximately 10 feet away from the treated site. Risk from chronic exposure was estimated to extend as far away from the treated site as 70 ft for birds and 1000 ft for mammals.

• non

- target terrestrial plants, b oth monocots and dicots, from spray drift and runoff. Risk from spray drift was estimated to extend up to 1000 ft from the treated site for ground or truck

- mounted sprayers.

• listed aquatic animals from acute exposure for some modeling scenarios.

• aquatic n on

- vascular and vascular plants.

The RED determined that prometon w as eligible for reregistration provided several risk mitigation measures and label amendments were adopted.

Mitigation measures and label amendments to address non

- target terrestrial expo sures to animals and plants, including spray drift, were as follows:

• The maximum use rate is reduced to 16 lbs a.i./ A for applications under block or solid paving.

• The maximum use rate is reduced to 18 lbs a.i./ A for all other industrial sites.

1 Per BEAD memo dated October 11, 20127 • End

- use product labels will include language requiring that weeds greater than 4 inches must be mowed, removed, or hoed into the soil prior to application.

• End

- use product labels will include language requiring that immediately after application,
treatmen t areas must be watered in with at least 1/4” of water or treatments will be made just prior to a rain event.

• Applications must be made using me dium

- to coarse

- sized droplets.

• Applications must not be made to sloped areas where desirable vegetation or adj acent water bodies are located downhill of the treatment area.

• Products containing prometon are limit ed to one application per year.

A litigation assessment for the federally

- listed Barton Springs salamander ( Eurycea sosorum ) was conducted in 2007 2 . This assessment concluded that use of prometon in the Barton Springs Segment of the Edwards Aquifer (BSSEA) may have the following effects: no effect based on a total yearly usage of <1,650 lbs ai; may affect, not likely to adversely affect (indirect) based on total yearly usage of ≥1,650 lbs ai but <22,000 lb ai; and may affect, likely to adversely affect (direct) based on total yearly usage of ≥22,000 lbs ai.

A drinking water assessment was performed for all uses of prometon on October 24, 2007 based on mode ling and monitoring data. Prometon degradation products were not considered in this drinking water assessment. Tier II PRZMIEXAMS modeling indicate prometon concentrations in surface source drinking water were not expected to exceed 92 μ g/L for the 1 in 1 0 year annual peak concentration, 70 μ g/L for the 1 in 10 year annual average concentration, and 44 μ g/L for the 30 year annual average concentration. Non

- targeted surface water monitoring program indicated a maximum observed prometon concentration of 25 μ g/L. The maximum average prometon concentration for a sampling site was 3.03 μ g/L. Tier I SCI

- GROW modeling predicted peak and chronic prometon concentration s in shallow groundwater of 706 μ g/L. Non

targeted ground water monitoring data indicated a max imum observed prometon concentration of 40 μ g/ L based on a 59.98 lbs ai/A application rate and 236 ug/L based on a 20.04 lbs ai/A application rate

.



### 3 Overview of Prometon Use

Prometon is registered for weed control at the following use sites: agricultural/farm structures/buildings and equipment, airports/landing field, commercial/institutional/industrial premises/equipment (outdoor), commercial storage/warehouse premises, fence rows/hedgerows, industrial/construction areas (outdoor), nonagricultural outdoor buildings/structures, nonagricultural rights

- of

- way/fencerows/ hedgerows, nonagricultural uncultivated areas/soils, paved roads (private roads/sidewalks), recreational areas, and utility poles/rights

- of

- way. Prometon is formulated as an emulsifiable concentrate, liquid, or pellet/tablet and is applied once per year via ground broadcast, ground spray, or sprinkle can at a maximum single application rate of 9.1 lb a.i./ A for rights

- of

- way specifically for utility poles and 18 lb a.i./ A for all other use sites (including other types of rights

- of

- way)

.

2 http://www.epa.gov/oppfead1/endanger/litstatus/effects/#prometon8 Based on usage information provided by the registrant, total annual sales of prometon are approximately 550,000

- 600,000 pound s of a.i.: approximately 60% is applied to building perimeters or fencerows; 30% is applied to industrial sites; and <1 0% is applied to rights

- of

- way

areas 3

.



### 4 Environmental Fate Summary

Prometon is persistent and mobile in the environment. Leaching and r unoff are expected to be important transport pathways for prometon (water solubility of 720 mg/L), while volatilization is not (vapor pressure of 7.73 × 10 - 6 ). Probable routes of dissipation from the use site are through runoff into surface water a nd leach ing into groundwater. Prometon is stable to abiotic hydrolysis and photodegradation in water and soil. Half

- lives of prometon range from 462 to 932 days in aerobic soil (study durations of 365 and 368 days) . In anaerobic s oil, the half

- life is 557 days (st udy duration of 120 day: 30 aerobic and 90 anaerobic) . Aerobic and anaerobic aquatic metabolism data are not available for this chemical. Degradation products of are shown in Table 4

- 1

.

Table 4

- 1 . Structures and B asic C hemistry and M obility D ata for P rometon and P rometon D egradates I dentified in R egistrant

- S ubmitted F ate S tudies Prometon (Parent)

Prometon Formula: C 10 H 19 N 5 O Molecular Weight: 225.30 Smiles Code: O(c(nc(nc1NC(C)C)NC(C)C)n1)C Water Solubility: 750 mg/L (25oC) (Tomlin, C. 1994) Koc: 137.4 L/kg (EPI Suite MCI method)

Prometon Degradates in Registrant

- submitted Fate Studies Prometon degradate GS

- 14626 Formula: C 7 H 13 N 5 O Molecular Weight: 183.21 Smiles Code: O(c(nc(nc1NC(C)C)N)n1)C Water Solubility: 836.3 mg/L (25oC) (EPI Suite WSKOW v1.41) Koc: 42.09 L/kg (EPI Suite MCI method)

Maximum % Formation a

Aerobic Soil Metabolism

– 15.4% (increasing at study end: 368 days) Anaerobic Soil Metabolism

– 5.3% Terrestrial Field Dissipation

– 1.3 ppm Prometon degradate GS

- 11526 b Synonym: 2

- hydroxypropazine CAS no.: 7374

- 53

- 0 Formula: C 9 H 17 N 5 O Molecular Weight: 211.27 Smiles Code: O(c(nc(nc1NC(C)C)NC(C)C)n1) Water Solubility: 275.3 mg/L (25oC) (EPI Suite WSKOW v1.41) Koc: 275.5 L/kg (EPI Suite MCI method)

3 Per BEAD memo dated October 11, 2012 N

N N OCH 3

N N CH 3

CH 3 H 3 C

CH 3

N

N N OCH 3

N NH 2 H 3 C

CH 3

N

N N OH

N N CH 3

CH 3 H 3 C

CH 39 Maximum % Formation a

Aerobic Soil Metabolism

– 8.5% (increasing at study end) Anaerobic Soil Metabolism

– 0.4% Terrestrial Field Dissipation

– NA Prometon degradate GS

- 12853 Formula: C 4 H 7 N 5 O Molecular Weight: 141.13 Smiles Code: O(c(nc(nc1N)N)n1)C Water Solubility: 22,850 mg/L (25oC) (EPI Suite WSKOW v1.41) Koc: 12.89 L/kg (EPI Suite MCI method)

Maximum % Formation a

Aerobic Soil Metabolism

– 0.32% (increasing at study end: 326 days) Anaerobic Soil Metabolism

– 0.07% (increasing at study end: 92 days) Terrestrial Field Dissipation

– 0.16 ppm Prometon degradate GS

- 17794 c Synonym s : desethyl

- 2

- hydroxy

- atrazine ; deethylhydroxyatrazine ; OIAT/ DHEA CAS no.: 19988

- 24

- 0 Formula: C 6 H 11 N 5 O Molecular Weight: 169.19 Smiles Code: O(c(nc(nc1N)NC(C)C)n1) Water Solubility: 7818 mg/L (25oC) (EPI Suite WSKOW v1.41) Koc: 84.38 L/kg (EPI Suite MCI method)

Maximum % Formation a

Aerobic Soil Metabolism

– 0.61% (increasing at study end: 326 days) Anaerobic Soil Metabolism

– 0.16% (increasing at study end: 92 days) Terrestrial Field Dissipation

– NA Prometon degradate GS

- 17791 d Synonyms: Ammeline, desethyl

- desisopropyl

- 2

- hydroxy

- atrazine (DIH) CAS No.: 645

- 92

- 1 Formula: C 3 H 5 N 5 O Molecular Weight: 127.11 Smiles Code: O(c(nc(nc1N)N)n1) Water Solubility: 208,300 mg/L (25oC) (EPI Suite WSKOW v1.41) Koc: 25.84 L/kg (EPI Suite MCI method)

Maximum % Formation a

Aerobic Soil Metabolism

– 0.13% (increasing at study end: 326 days) Anaerobic Soil Metabolism

– 0.01% (increasing at study end: 92 days) Terrestrial Field Dissipation

– NA NA = Not analyzed

a Because prometon is stable to abiotic hydrolysis and the aerobic and anaerobic aquatic metabolism studies have not been submitted, only % formation data is available from the aerobic and anaerobic soil metabolism and terrestrial field dissipation studies.
b Also degradate of propazine and prometryn

c Also degradate of propazine, prometryn, and atrazine
d Also degradate of propazine and atrazine

Prometon is expected to be mobile in both soil and aquatic environments. The average Ko c of prometon in five agricultural soils is 117 L/kg (range = 82.6 to 172) . The fate properties of prometon are presented in Table 4

- 2 for the parent only. No fate data (other than that presented in Table 4

- 1 ) are available for the degradates of prometon. N

N N OCH 3

H 2 N NH 2

N

N N OH

H 2 N N CH 3

CH 3

N

N N OH

H 2 N NH 210 Table 4

- 2

. Fate Profile for Prometon Physico

- chemical Characteristic Value Source Vapor Pressure ( mm Hg @ 20oC) 7.73 × 10 - 6 MRID 41609103 Water Solubility (mg/L @ 20oC) 7 20 MRID 41609103 Log K OW (@2 5 oC) 2.69 MRID 41609103 Hydrolysis Stable in pH 5, 7, and 9 MRID 41114801 Photodegradation in Water Stable MRID 40225801 Photodegradation on Soil Stable MRID 41114802

Aerobic Soil Metabolism t 1/2 = 462 days

t 1/2 = 932 days MRID 4145501

MRID 42313501

Anaerobic Soil Metabolism Stable during 90 days, after 30 days aerobic
t 1/2 = 462 days Stable during 60 days, after 32 days aerobic
t 1/2 = 557 days MRID 40145501

MRID 42313501

Adsorption/desorption K d = 2.61 (1/n=0.893) ; Koc = 149.6 CA sandy loam K d = 2.90 (1/n=0.895) ; Koc = 172.0 Dubuque silt loam K d = 2.40 (1/n=0.868) ; Koc = 82.6 Kewaunee clay loam K d = 1.20 (1/n=0.911) ; Koc = 98.3 MS silt loam K d = 0.398 (1/n=0.738) ; Koc = 85.6 Plainfield sand MRID 40225803

Terrestrial Field Dissipation t 1/2 =200 to 400 days

– Fresno, CA MRID 00 162534 MRID 00 162535 MRID 00 162536

Pro meton is not identified as a cause of impairment for any water bodies listed as impaired under section 303(d) of the Clean Water Act 4 . In addition, no Total Maximum Daily Loads (TMDL) have been developed for prometon 5 . The Impaired Wate rs and Total Maximum Daily Loads website can be consulted for more information 6 . The Agency invites submission of water quality data for this pesticide. To the extent possible, data should conform to the quality standards in Appendix A of the OPP Standard Operating Procedure: Inclusion of Impaired Water Body and Other Water Quality Data in OPP’s Registration Review Risk Assessment and Management Process 7 , in order to ensure they can be used quantitatively or qualitatively in pesticide risk
assessments.



### 5 Eco logical Effects Summary

5.1 Parent: Prometon

S tudies characterizing the toxicity of prometon are provided in Table 5

- 1

. No studies have been submitted since the 200 8 RED.

4 http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885
5 http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_pollutant_
gr oup_name=PESTICIDES
6 http://www.epa.gov/owow/tmdl /
7 http://www.epa.gov/oppfead1/cb/ppdc/2006/november06/session1

- sop.pdf11 Prometon is practically non

- toxic to birds on an acute oral and sub

- acute dietary bas is ; practically non

- toxic to terrestrial invertebrates on an acute contact basis ; and slightly toxic to fish and aquatic invertebrate s on an acute basis.

The study with green alga Selenastrum capricornutum (MRID 41725305) had been classified as Supplemental because the maximum application rate was not given in the study report. The classification of this study has been upgraded to Acceptable because the lack of a reported maximum application rate does not affect the scientific soundness of the s tudy, and the study fulfills the guideline requirement for a freshwater algae toxicity study ; the endpoints remain unchanged.

For the early life stage (ELS) study with fathead minnow (MRIDs 41810902, 42318202), a definitive NOEC was not previously determi ned for the most sensitive parameter of length ( i.e.

, NOEC < 4.85 mg a.i./ L; LOEC = 4.85 mg a.i./ L). A re

- analysis of the raw data for survival, hatching, length, and dry weight yielded a definitive NOEC of 19.7 mg a.i./ L and a LOEC of 37.0 mg a.i./ L base d on the most sensitive parameters of survival and hatching. The classification for the ELS study as Acceptable remains the same.

Registrant

- submitted data are n ot available for the following:

• acute toxicity to a passerine,

• chronic toxicity to an estuari ne/marine fish and invertebrate

,

• toxicity to 3 species of aquatic non

- vascular plants: cyanobacterium, freshwater diatom, and marine diatom, and

• toxicity to an aquatic vascular plant ( i.e.

, Lemna spp.)

. In previous ecological risk assessments (200 8 RED, D P 335306; 2007 litigation assessment for the federally

- listed Barton Springs salamander), ECOTOX open literature studies E009211 and E081431 were referenced for characterizing the toxicity of prometon to marine algae and aquatic vascular plants ( i.e.

, Lemn a spp.), respectively. Formal reviews of these studies conducted in accordance with current guidelines for evaluating ecological toxicity data in the open literature 8
resulted in their classification as qualitative for use in the Registration Review ecolo gical risk
assessment due to the lack of sufficient experimental details ( e.g. , replication, test concentrations). In addition, a rainbow trout acute endpoint ( i.e. , LC 50 = 12 mg/L) of ECOTOX open literature study E000546 was used in the RQ calculation for freshwater fish in the 200 8 RED and litigation assessments because it was the most sensitive endpoint . This study will be reviewed to determine whether its results can be used quantitatively in the Registration Review ecological risk assessment.

It should be noted that the chronic, early life stage endpoint of 19.7 mg/L for freshwater fish (fathead minnow; MRIDs 41810902, 42318202) is approximately equal to the most sensitive acute endpoint of 19.6 mg/L for freshwater fish (rainbow trout; MRID 416091 08). This discrepancy is probably due to the differen t species used in the test s ( i.e.

, fathead minnow in the

8 http://www.epa.gov/pesticides/science/efed/policy_guidance/team_authors/endangered_species_rereg istration_work group/esa_evaluation_open_literature.htm12 chronic test and rainbow trout in the acute test) and will be addressed in the Section 9 of this document.

Table 5

- 1. Summary of the Endpoi nts from Toxicity Studies with Prometon

Study Type TGAI/TEP (%) Species Toxicity Endpoints a , Effects & Classification Source & Classification

Avian acute oral TGAI (98.5) Bobwhite quail ( Colinus virginianus ) LD 50 > 2264 mg a.i./ kg

- bw NOEL < 294 mg a.i./ kg

- bw (no mortality; NOEL based sublethal effects including ruffled appearance, lethargy, s/a, reduced reaction to external stimuli, loss of coordination, lower limb weakness, depression, wing droop, and rapid respiration; also dose

- response reduction in b ody weight at ≥ 489 mg a.i./ kg

- bw from days 0

- 3) Practically non

- toxic MRID 41609104 Acceptable

Avian acute oral TGAI (NS) Mallard duck ( Anas platyrhynchus ) LD 50 = 3157 mg/kg

- bw (symptoms preceding death included depression, wing droop, loss of coordination, prostrate posture, loss of righting reflex, convulsions, salivation, and shallow and rapid respiration; first death: 15 minutes after dosing at 4640 mg/kg

- bw) Practically non

- toxic MRID 00079616 Acceptable

Avian acute oral Passerine No data

Avian sub

- acute dietary TGAI (98.5) Bobwhite quail ( Colinus virginianus ) LC 50 > 5620 mg/kg

- diet NOEC = 1000 mg/kg

- diet (no mortality; NOEC based on lethargy and ruffled appearance at ≥ 1780 mg/kg

- diet; also reduction in feed consumption at 5620 mg/kg

- diet) Practically non

- toxic MRID 41609105 Acceptable

Avian sub

- acute dietary TGAI (98.5) Mallard duck ( Anas platyrhynchus ) LC 50 > 5620 mg/kg

- diet NOEC < 562 mg/kg

- diet (no mortality; NOEC based on dose

- response reduction in weight gain; also reduction in feed consumption at ≥ 1780 mg/kg

- diet) Practically non

- toxic MRID 41606106 Acceptable

Avian reproduction TGAI (98.5) Bobwhite quail ( Colinus virginianus ) NOEC = 175 mg a.i./ kg

- diet LOEC = 600 mg a.i./ kg

- diet (based on a reduction in the number of viable embryos and live

- 3

- week embryos) MRID 42132101 Acceptable

Avian reproduction TGAI (98.5) Mallard duck ( Anas platyrhynchus ) NOEC = 50 mg a.i./ kg

- diet LOEC = 175 mg a.i./ kg

- diet (based on a reduction in adult body weight and eggshell thickness) MRID 42132102 Acceptable

Terrestrial invertebrate acute
contact TGAI (98.5) Honeybee ( Apis mellifera ) 48

- hr LD 50 (95% C.I.) = 37 (30.9

- 44.7) μg a.i./ bee Probit slope = 2.19 48

- hr NOEC < 13 μg a.i./ bee (NOEC based on mortality and immobility) Practically non

- toxic MRID 41609115 Acceptable

Terrestrial plant Tier II

s eedling emergence TGAI (98.5) Most sensitive monocot: Oat 21

- day EC 25 = 0.0270 lb a.i./A 21

- day NOEC = 0.0047 lb a.i./ A (based on dry weight) MRID 41725303 Acceptable Most sensitive dicot: Lettuce 21

- day EC 25 = 0.0100 lb a.i./ A 21

- day NOEC = 0.0094 lb a.i./ A (based on dry weight)13 Study Type TGAI/TEP (%) Species Toxicity Endpoints a , Effects & Classification Source & Classification
Terrestrial plant Tier II

v egetative vigor TGAI (98.5) Most sensitive monocot: Oat 21

- day EC 25 = 0.016 lb a.i./A 21

- day NOEC = 0.012 lb a.i ./ A (based on dry weight) MRID 41725304 Acceptable Most sensitive dicot: Lettuce 21

- day EC 25 = 0.0080 lb a.i./ A 21

- day NOEC = 0.0047 lb a.i./ A (based on dry weight) Freshwater fish
acute TGAI

Rainbow trout ( Oncorhynchus mykiss ) 96

- hr LC 50 = 12 mg/L E000546 In review

Freshwater fish
acute TGAI (98.5) 96

- hr LC 50 (95% C.I.) = 19.6 (17.1

- 22.4) mg a.i./L (m) Probit slope = 8.6 96

- hr NOEC = 6.36 mg a.i./L (m) (NOEC based on sublethal effects including discoloration, lethargy, hyperventilation, erratic swimming, and loss of equilibrium) Slightly toxic MRID 41609108 Acceptable

Freshwater fish
acute TGAI (98.5) Bluegill sunfish ( Lepomis macrochirus ) 96

- hr LC 50 = 41.5 mg a.i./L (m) 96

- hr NOEC = 1.36 mg a.i./L (m) (NOEC based on sublethal effects including discoloration, lethargy, loss of equilibrium; mortality only at highest test concentration of 58.8 mg a.i./L) Slightly toxic MRID 41609107 Acceptable

Freshwater fish chronic: Early life stage TGAI (98.5) Fathead minnow ( Pimephales promelas ) 33

- day NOEC = 19.7 mg a.i./L (mm) 33

- day LOEC = 37.0 mg a.i./L (mm) (based on a reduction in survival and hatching) MRIDs 41810902, 42318202 b Acceptable

Estuarine/marine fish acute TGAU (98.5) Sheepshead minnow ( Cyprinodon variegatus ) 96

- hr LC 50 = 47.3 mg a.i./L (im) 96

- hr NOEC = 3.99 mg a.i./L (im) (NOEC based on sublethal effects including lethargy, loss of equilibrium, surfacing, discoloration, erratic swimming) Slightly toxic MRID 41725301 Acceptable

Estuarine/marine fish chronic No data

Freshwater invertebrate acute TGAI (98.5) Water flea ( Daphnia
magna ) 48

- hr EC 50 (95% C.I.) = 25.7 (20.7

- 32.0) mg a.i./L (m) Probit slope = 3.18 (NOEC not determined; immobility at all test concentrations) Slightly toxic MRID 41609109 Acceptable

Freshwater invertebrate chronic TGAI (97.7) Water flea ( Daphnia
magna ) 21

- day NOEC = 3.45 mg a.i./L (mm) 21

- day LOEC = 6.77 mg a.i./L (mm) (based on a reduction in offspring production) MRID 41810903 Acceptable

Estuarine/marine invertebrate acute TGAI (98.5) Mysid shrimp ( Mysidopsis bahia ) 96

- hr LC 50 (95% C.I.) = 17.7 (13.9

- 23.4) mg a.i./L (m) Probit slope = 3.1 96

- hr NOEC = 4.44 mg a.i./L (m) (NOEC based on mortality; mortality at all test concentrations) Slightly toxic MRID 41609110 Acceptable14 Study Type TGAI/TEP (%) Species Toxicity Endpoints a , Effects & Classification Source & Classification

Estuarine/marine invertebrate acute TGAI (97.7) Eastern oyster ( Crassostrea virginica ) 96

- hr EC 50 = 27.50 mg a.i./L (mm) 96

- hr NOEC = 8.61 mg a.i./L (mm) (NOEC based on statistically

- significant shell deposition) Slightly toxic MRID 41810901 Acceptable

Estuarine/marine invertebrate chronic No data

Benthic invertebrate whole sediment No data

Aquatic non

vascular plant TGAI (97) Green alga ( Selenastrum capricornutum ) 5

- day EC 50 (9 5% C.I.) = 0.098 (0.088

- 0.108) mg a.i./ L (mm) Probit slope = 3.41 5

- day NOEC = 0.032 mg a.i./L (mm) (based on cell count) MRID 41725305 Acceptable c

Aquatic non

vascular plant Cyanobacterium No data
Aquatic non

vascular plant Freshwater diatom No data
Aquatic non

vascular plant Marine diatom No data
Aquatic vascular plant Duckweed No data
NS = not specified; C.I. = confidence interval

a (im) = initial measured; (m) = measured; (mm) = mean

- measured; (nom) = nominal
b A 1992 re

- review of the study after submission of raw length and weight data found that the study fulfilled the

guideline requirement. However, a definitive NOEC was not determined for the most sensitive parameter of length ( i.e. , NOEC < 4.85 mg a.i./ L; LOEC = 4.85 mg a.i./ L). A re

- analysis of the raw data for survival, hatching, length, and dry weight yielded a definitive NOEC of 19.7 mg a.i./ L and a LOEC of 37.0 mg a.i./ L based on the most sensitive parameters of survival and hatching.

c upgraded from Supplemental (based on the maximum application rate not being provided in the study report) to

Acceptable

5.2 Prometon Degradates

Five major degradates of prometon have been identified based on environmental fate studies: GS

- 11526, GS

- 14626, GS

- 17794, GS12 853, and GS

- 17791 ( Table 4

- 1 ). There are no registrant

- submitted toxicity data available for these degradates.

In the absence of toxicity data, predicted acute and chronic toxicity values for the major degradates of prometon were generated us ing EPA’s ECOSAR 9 tool (v 1.1 ) which is based on quantitative structure activity relationships (QSAR) for effects on fish, daphnids, and green algae . Predicted toxicity values were also generated for parent prometon and compared to observed endpoints from registran t

- submitted studies to assess confidence in the ability of ECOSAR to predict the toxicity of prometon’s degradates. The ECOSAR class of “triazines, aromatic” was used for comparative purposes even though output for other ECOSAR classes was

9 http://www.epa.gov/oppt/newchems/tools/21ecosar.htm15 available for t he degradates 10

. ECOSAR

- predicted and observed toxicity values for prometon and its major degradates are provided in Table 5

- 2

. If available, observed toxicity endpoints for degradates of other triazines that are closely related ( i.e. , have similar struct ures) to prometon degradates were also examined.

5.2.1 ECOSAR

- Predicted vs. Observed Toxicity Endpoints for Parent Prometon

ECOSAR

- predicted toxicity values for parent prometon were 1

- 2 orders of magnitude less than observed toxicity endpoints for fish, daphnid s, and mysids implying that ECOSAR over

predicted toxicity to prometon for these taxa. In contrast, ECOSAR

- predicted toxicity values for parent prometon were an ~3 times less than observed toxicity endpoint for green algae implying that ECOSAR marginally over

- predicted toxicity to prometon for this taxon.

5.2.2 GS

- 11526

Demethylation of the methoxy group of parent prometon produces d egradate GS

- 11526

. GS

11526 is also a degradate of other triazine herbicides including propazine and prometryn. ECOSAR

- predic ted toxicity values indicate that GS

- 11526 is approximately as toxic as parent prometon , particularly with respect to green algae

T oxicity data for fish and aquatic invertebrates are available for the closely

- related degradate of atrazine, hydroxyatrazine (HA, G

- 34048 ; CAS No. 2163

- 68

- 0) . Given their structural similarity, the toxicity of hydroxyatrazine likely provides a reasonable approximation of the toxicity of GS

11526 ( Table 5

- 3 ). HA was not tested to high enough levels to yield definitive endpoints due to its limited solubility (see footnotes of Table 5

- 2 ). These observed non

- definitive endpoints do not contradict the ECOSAR

- predicted toxicity values, but do not provide any additional insight about the toxicity of GS

- 11526 because the highest concentrations tested are less than modeled concentrations.

Collectively, these approaches indicate that the toxicity of GS

- 11526 to aquatic taxa is
compa rable to that of parent promet on. Therefore, GS

- 11526 will be considered a stressor of concern in the Registration Review ecological risk assessment.

10 ECOSAR classes (besides triazines): GS

- 11526

– phenols; GS

- 14626

– anilines (un hindered); GS

- 17794

–

anilines (unhindered), phenols, phenol amines; GS

- 12853

– anilines (amino

- meta & unhindered); GS

- 17791

– anilines (amino

- meta & unhindered), phenols, phenol amines16 Table 5

- 2. ECOSAR

- predicted and Observed Toxicity Values for Prometon and Major D egradates
Taxon Exposure duration Toxicity Value (mg/L) Observed ECOSAR

- Predicted (Using ECOSAR Class Triazines) Prometon GS

- 11526 a ,b GS

- 14626 GS

- 17794 c GS

- 12853 GS

- 1779 1 d

FW fi sh 96

- hr LC 50 Chronic value 19.6

- 41.5 19.7 5.15 0.143 39.2 e 1.0 74.7 1.9 559.6 13.8 1027 24.8 7500 171.6 SW fish 96

- hr LC 50 Chronic value 47.3 No data 6.1 0.674 31.4 f
2.1 51.6 2.9 260.5 9.0 411.9 11.9 2027.4 35.9 Daphnid 48

- hr EC/LC 50 Chronic Value 25.7 3.45 6.573 0.256 26.4 g 1.1 39.6 1.7 156.3 7.1 225.5 10.5 869.0 43.3 Mysid shrimp 96

- hr LC 50 Chronic value 17.7 No data 0.874 0.085 4.6 h
1.6 7.7 4.4 39.7 81.7 63.5 211.7 321.5 3868.3 Green

a lgae 96

- hr EC 50 Chronic value 0.098 0.038 0.031 0.106 0.062 0.138 0.072 0.376 0.144 0.471 0.160 1.255 0.311 FW = freshwater; SW = saltwater

a also degradate of prometryn and propazine
b closely related to hydroxyatrazine (HA), a degradate of atrazine

c also degradate of prometryn, propazine, and atrazine
d also degradate of propazine and atrazine

e observed toxicity values for related degradate HA: LC 50 > 3.8 mg/L for bluegill sunfish (MRID 46500005); LC 50 > 3.0 mg/L for rainbow trout (MRID 46500004)
f observed toxicity values for related degradate HA: LC 50 > 1.9 mg/L for sheepshead minnow (MRID 46500006)

g observed toxicity values for related degradate HA: LC 50 > 4.1 mg/L for water flea (MRID 46500001)
h observed toxicity values for related degradate H A: LC 50 > 2.0 mg/L for mysid shrimp (MRID 46500001)

Table 5

- 3. Comparison of Structures for Prometon Degradate GS

- 11526 and Atrazine Degradate G

- 34048 (Hydroxyatrazine) Prometon Degradate GS

- 11526 Atrazine Degradate G

- 34048 Hydroxyatrazine N

N N OCH 3

N N CH 3

CH 3 H 3 C

CH 3 N

N N OH

N N CH 3

CH 3 H 3 C

CH 3 N

N N OCH 3

N NH 2 H 3 C

CH 3 N

N N OH

H 2 N N CH 3

CH 3 N

N N OCH 3

H 2 N NH 2 N

N N OH

H 2 N NH 2

N

N N OH

N N CH 3

CH 3 H 3 C

CH 3 N

N N OH

N N CH 3

CH 3 H 3 C

CH 317 5.2.3 GS

- 14626 and GS

- 17794

Removal of an isopropyl group ( i.e.

, R group) from parent prometon and GS

- 11526 produces degradates GS

- 14626 and GS

- 17794, respectively. GS

- 17794 is also a degradate of atrazine ( i.e.

, deethylhydroxyatrazine; OIAT/ DHEA ), propazine, and prometryn. ECOSAR

- predicted toxicity values indicate th at GS

- 14626 is approximately as toxic as parent prometon, particularly with respect to green algae, and that GS

- 17794 is less toxic than parent prometon to all taxa evaluated. Therefore, GS

- 17794 will not be considered a stressor of concern in the Registration Review ecological risk assessment. In contrast, S

- 14626 will be considered a stressor of concern in the Registration Review ecological risk assessment.

5.2.4 GS

- 12853 and GS

- 17791

Removal of an isopropyl group ( i.e.

, R group) from degradates GS

- 1 4626 and GS

- 17794 produces degradates GS

- 12853 and GS

- 17791, respectively. Thus these triazine degradates do not have any R groups. GS

- 17791 is also a degradate of atrazine ( i.e.

, desethyl

- desisopropyl

- 2

- hydroxy

- atrazine; DIH) and propazine. ECOSAR

- predicted toxicity values indicate that GS

12583 and GS

- 17791 are less toxic than parent prometon to all taxa evaluated. Furthermore, the toxicity of triazines generally decreases with loss of substituted R groups (Marchini et al., 1988)

. Therefor e, GS

- 12853 and GS

- 17794 will not be considered as stressors of concern in the Registration Review ecological risk assessment

.

5.2.5 Summary of Degradate Toxicity

ECOSAR

- predicted toxicity values indicate that GS

- 11526 and GS

- 14626 are approximately as toxic a s parent prometon, particularly with respect to green algae. Therefore, these degradates will be considered stressors of concern in the Registration Review ecological risk assessment. In contrast, ECOSAR

- predicted toxicity values indicate that GS

- 17794, GS

- 12853, and GS

- 17791 are less toxic than parent prometon to all taxa evaluated. Thus, these degradates will not be considered stressors of concern in the Registration Review ecological risk assessment

.

5.3 Review of Incident Databases

Reviews on October 25 , 2012 of the Ecological Incident Information System 11 (EIIS, version 2.1.1), which is maintained by the Agency’s Office of Pesticide Programs, and the Avian Monitoring Information System (AIMS), which is maintained by the American Bird Conservatory, indi cate a total of two reported ecological incidents (in EIIS) associated with the use of prometon

. One incident (#I005895

- 355) involved fish mortality in a Kansas pond from an accidental misuse of prometon resulting in spillage. T he certainty category rega rding the likelihood that the use of prometon caused this incident is ‘probable ’. The second incident (#I014409

- 078) involved damage to terrestrial plants including trees and lawn from misuse of

11 http://www.epa.gov/espp/consultation/ecorisk

- overview.pdf18 prometon on a Washington roadway by a paving contractor. The certainty category regarding the likelihood that the use of prometon caused this incident is ‘possible’.

In addition to the incidents recorded in EIIS and AIMS, additional incidents are reported to the Agency in aggregated form. Pesticide registrants report certain types of incidents to the Agency as aggregate counts of incidents occurring per product per quarter. Ecological incidents reported in aggregate reports include those categorized as ‘minor fish and wildlife’ (W

- B), ‘minor plant’ (P

- B), and ‘other non

- target’ (ONT) incidents. ‘Other non

- target’ incidents include reports of adverse effects to insects and other terrestria l invertebrates. For prometon , registrants have reported no minor fish and wildlife incidents, 12 minor plant incidents, an d no other non

- target incidents as of October 25, 2012.

The total number of actual incidents associated with the use of prometon may be higher than what is reported to the Agency. Incidents may go unreported since effects may not be immediately apparent and/or readily attrib uted to the use of a chemical.



### 6 Risk Hypothesis

T he Registration Review ecological risk assessment will test the following risk hypothesis :

Based on the application methods, the assumed fate and transport, and the assumed sensitivity of non

- target aquatic and terrestrial species, prometon has the potential to reduce survival, growth, and/or reproduction of non

- target terrestrial and aquatic organisms as well as negatively affect the structure, productivity, and function of aquatic pla nt communities when used in accordance with the current labels. These non

- target organisms include Federally

- listed threatened and endangered species as well as non

- listed species.



### 7 Exposure Pathways of Concern

For terrestrial vertebrates , the major route of exposure to prometon is considered to be via dietary ingestion of food items such as plants and/or animals that have prometon residues as a result of direct application, spray drift, and runoff . Exposure to terrestrial vertebrates through inhalation i s considered unlikely given prometon ’s low vapor pressure; however, a more quantitative analysis of risk through inhalation exposure via EFED’s Screening Tool for Inhalation Risk (STIR v. 1.0) is not possible because the lowest rat inhalation endpoint is n on

- defin i tive (LC 50 > 0.52 mg/L; MRID 42132104). EFED’s Screening Imbibition Program (SIP v. 1.0) indicates potential risk to birds but not to mammals from acute and chronic exposure through the consumption of drinking water with prometon residues ( Appendix A ).

For terrestrial invertebrates, the major routes of exposure to prometon are considered to be direct contact as a result of direct application and spray drift and dietary ingestion of plants, animals, and/or soil that have prometon residues as a result of direct application, spray drift, and runoff. Exposure to terrestrial invertebrates could also occur through guttation water.19 For aquatic animal species, the major route of exposure to prometon is considered to be uptake via the respiratory s urface (gills) or the integument from surface water/sediment that has prometon residues as a result of spray drift, runoff, and leaching to groundwater from soil

. For terrestrial (upland and semi

- aquatic) non

- target plants, the major routes of exposure to prometon are considered to be d i rect contact as a result of direct application and spray drift and root uptake via soil contaminated via spray drift and runoff.

For aquatic plants, the major route s of exposure to prometon are considered to be uptake from surface water/sediment containing prometon residues as a result of spray drift, runoff, and leaching to groundwater from soil.



### 8 Analysis Plan

To address the risk hypothesis, the potential for adverse effects on the environment will be estimated. Usage, environmental fate, and ecological effects of prometon will be characterized and integrated to assess the risks. Risk quotients (RQs) will be d erived for prometon by dividing estimated exposure concentrations ( EEC s) by the most sensitive endpoint from the relevant, available toxicity data for prometon

. A s outlined in the Overview Document (USEPA, 2004), the likelihood of effects to individual or ganisms from particular uses of a chemical is estimated using the probit dose

- response slope and either the lev el of concern (LOC) or the actual calculated risk quotient value.

This analysis plan will be revisited and may be revised depending upon a full review of the data available in the open literature and the information submitted by the public in response to the opening of the Registration Review docket.

8.1 Stressors of Concern

Comparative toxicity modeling conducted in Section 5 indicate s that GS

- 11526 and GS

- 14626 are approximately as toxic as parent prometon to aquatic organisms . Therefore, in addition to parent prometon, these degradates will be considered stressors of concern in the Registration Review ecological risk assessment. In the ab sence of data on the toxicity of GS

- 11526 and GS

14626

, the conservative method of considering the stressors of concern in total, i.e. , the total toxic residue (TTR) approach will be used.

8.2 Measures of Exposure

To estimate risks to aquatic and terrestria l organisms from exposure to prometon , all exposure modeling and resulting risk conclusions will be made based on maximum application rates, application methods, and any mitigation measures specifically indicated on the label

. Models that will be used to predict estimated environmental concentrations (EECs) of prometon are discussed on OPP’s model website 12 . These models include: PRZM ( P esticide R oot Z one

12 http://www.epa.gov/pesticides/science/models_db.htm20 M odel) and EXAMS ( EX posure A nalysis M odeling S ystem), PRZM

- groundwater ( PRZM

- GW), T

- REX, and TerrPlant

.

8.3 Measures of Effect

Ecological effects data are used as measures of direct and indirect effects to non

- target organisms. D ata are obtained from registrant

- submitted studies or from literature studies identified by ECOTOX 13 . Information on the potentia l effects of prometon to non

- target organisms is also collected from reviews of incidents associated with the use of prometon (see Section 4.3 ).

Where available, sub

- lethal effects observed in both registrant

- submitted and open literature studies will be evaluated qualitatively. Such effects may include behavioral changes ( e.g. , lethargy and changes 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.

The assessment of risk for direct effects to non

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

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

- phase amphibians.

8.4 Integration of Exposure and Effects

Risk characterization is the integration of exposure and ecological effect characterizations to determine the potential ecological risk from the use of prometon and the likelihood of direct and indirect effects to non

- target organisms in aquatic and terrestrial habitats. The exposure and effec ts data are integrated to evaluate potential adverse ecological effects on non

- target species. For the prometon risk asse ssment, the risk quotient (RQ) method will be used to compare estimated exposure and measured toxicity values. Acute and chronic EECs will be divided by acute and chronic toxicity values. The resulting RQs will then be compared to the Agency’s Levels of Concern (LOC) (USEPA, 2004). These criteria are used to indicate when prometon’s use, as directed on the labels, has the potential to cause adverse direct or indirect effects to non

target organisms. In addition, incident data from EIIS, aggregate incide nt reports, and AIMS will be considered as part of the risk characterization.

8.5 Drinking Water Assessment

A comprehensive drinking water assessment (based on all currently registered uses ) may be conducted if requested by the Health Effects Division (HED) to support future human health dietary risk assessments of prometon as part of the Registration Review process

. Any new drinking water assessment w ould incorporate model estimates as well as available monit oring data for prometon and any transformation products of toxicological concern (drinking water

13 http://cfpub.epa.gov/ecotox/21 assessment residues of concern) that might be identified by HED for surface water and/or groundwater. The final determination of the residues of concern will b e made through consultation with HED and through any proceedings of the ROCKS (Residues of Concern Knowledge Subcommittee).

8.6 Endangered Species Assessments

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

- listed threatened and/or endangered (listed) species from registered uses of prometon . This assessment will be conducted i n accordance with the Overview Document (USEPA, 2004), provisions of the ESA, and the Services’ Endanger ed Species Consultation Handbook (USFWS/NMFS, 1998).

The assessment of effects associated with the registration of prometon 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 exceedance 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 as sessment process to establish 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 ac tion ( i.e ., the area where prometon application occurs), plus all areas where offsite transport ( i.e ., spray drift, runoff, etc .) may result in potential exposure that exceeds the Agency’s LOCs. Specific measure s of ecological effect that define the actio n 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 sub

- lethal effects available in the effects lite rature. Therefore, the action area extends to a point where environmental exposures are below any measured lethal or sub

- lethal effect threshold for any biological entity at the whole organism, organ, tissue, and cellular level of organization. In situat ions where it is not possible to determine the threshold for an observed effect, the action area will be assumed to encompass the entire United States.

8.7 Endocrine Disruptor Screening Program

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and chronic toxicity, including assessments of carcinogenicity, neurotoxici ty, developmental, reproductive, and general or systemic toxicity. These studies include endpoints which may be susceptible to endocrine influence, including effects on endocrine target organ histopathology, organ weights, estrus cyclicity, sexual maturati on, fertility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and chronic studies that assess growth, developmental and reproductive effects in different taxonomic groups. As part of the most recent registration decision , EPA reviewed these data and selected the most sensitive endpoints for relevant risk assessment scenarios from the existing hazard database. However, as required by FFDCA section 408(p), prometon is subject to the endocrine screening part of the Endocrine Disr uptor Screening Program (EDSP).22 EPA has developed the EDSP to determine whether certain substances (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an effect 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 screenin g assays 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 hormon al systems 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 substan ce, and establish a dose

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

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between October 2009 and February 2010, EPA issued test orders/data call

- ins for the fir st group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. Prometon was not among the group of 58 pesticide active ingredients on the initial list to be screened under the EDSP. Accordingly, as part of Registration R eview, EPA will issue future EDSP orders/data call

- ins, requiring the submission of EDSP screening assays for prometon

. For additional information on the EDSP program, visit http://www.epa.gov/endo/

.



### 9 Data Gaps

The following two sections identify environmental fate and effect s data that are needed to complete an environmental fate and ecological risk assessme nt in support of the Registration R eview of the registered uses of prometon.

9.1 Environmental Fate Data

Table 9

- 1 lists the status of the fate and transport data requirements for prometon . The fate database for prometon is c omplete (with the exception of aerobic aquatic metabolism studies and the analytical methods for soil, water, and sediment as noted in Table 9

- 1 ).

Table 9

- 1. Registrant

- Submitted Fate Data for Prometon and Remaining Data Gaps

Guideline Description MRID/ Source Classification Data Gap?

835.2120 161

- 1 Hydrolysis 00146155 41114801 Unacceptable Acceptable No

835.2240 161

- 2 Photodegradation in Water 40225801
92149014 Acceptable No

835.2410 161

- 3 Photodegradation in Soil 40225802
41114802 Una cceptable Acceptable No

835.4100 162

- 1 Aerobic Soil Metabolism 40145501 42313501 Acceptable Acceptable No23 Guideline Description MRID/ Source Classification Data Gap?

835.4200 162

- 2 Anaerobic Soil Metabolism 40145501 42313501 Acceptable Supplemental No

835.4300 162

- 4 Aerobic Aquatic Metabolism

-- -- Yes

835.4400 162

- 3 Anaerobic Aquatic Metabolism

-- -- Yes

835.1230 835.1240 163

- 1 Leaching

- Adsorption/ Desorption 40225803 Acceptable No

835.6100 164

- 1 Terrestrial Field Dissipation 00162534
0016253 5
0016253 6 Acceptable No

850.6100 Analytical Method

- Soil

-- -- Yes

850 .6100 Analytical Method

- Water

-- -- Yes

850 .6100 Analytical Method

- Sediment

-- -- Yes

850.1730 165

- 4 Accumulation in fish 00125927
00125930 Acceptable No

166

- 2 Ground Water

- small retrospective 45058801
45058802 Supplemental Supplemental No

Submission of data to eliminate data gaps would reduce uncertainties in the exposure assessment. Data gaps have been assigned either a low or high potential to add value to the Registration Review risk assessment . While still considered data gaps according to 40 CFR Part 158, low potential studies are unlikely to change risk determinations because alternate methods and weight of evidence may possibly be used in the absence of data. High potential studies would enable the Agency to better characterize potential risks by eliminating exposure uncertainties that cannot be accounted for us ing alternate methods or weight of evidence.

Data from the following guideline studies are considered to have high potential to add value to the exposure assessment for prometon :

Guideline 835.4300

– Aerobic Aquatic Metabolism : Data for aerobic aquatic metabolism are required under 40 CFR Part 158. Given that the 200 8 RED (DP 335306) identified a risk concern for aquatic organisms, fulfilling this data requirement has a high potential to add value to the Registration Review ecological risk assessment. In the abs ence of this data, the Agency will conservatively assume that prometon is stable to aerobic aquatic metabolism

. D egradation measured in a new metabolism study would lower the exposure predicted by the agency’s aquatic modeling efforts.

Guideline 835.4 4 00

– A na erobic Aquatic Metabolism : Data for a na erobic aquatic metabolism are required under 40 CFR Part 158. Given that the 200 8 RED (DP 335306) identified a risk concern for aquatic organisms, fulfilling this data requirement has a high potential to add val ue to the Registration Review ecological risk assessment. In the absence of this data, the Agency24 will conservatively assume that prometon is stable to anaerobic aquatic metabolism

. Any degradation measured in a new metabolism study would lower the exposure predicted by the agency’s aquatic modeling efforts.

Data from the following guideline studies are considered to have low potential to add value to the exposure assessment for prometon :

Guideline 850.6100

– Analytical Method s

– Soil , Water, and Se diment : Analytical methods for soil, water, and sediment are required under 40 CFR Part 158. However, prometon is already incorporated into U.S. Geological Survey multi

- residue monitoring methods. Therefore in terms of performing an ecological risk asses sment, little would be gained from these single residue analytical methods.

A dditional information that would have high potential to add value to the exposure modeling performed in the risk assessment would be detailed descriptions of the maximum spatial extent of prometon applications for all registered uses: agricultural/farm structures/buildings and equipment, airports/landing field, commercial/institutional/industrial premises/equipment (outdoor), commercial storage/warehouse premises, fencerows/hedge rows, industrial/construction areas (outdoor), nonagricultural outdoor buildings/structures, nonagricultural rights

- of

- way/fencerows/ hedgerows, nonagricultural uncultivated areas/soils, paved roads (private roads/sidewalks), recreational areas, and utilit y poles/rights

- of

- way. Prometon is used to kill all vegetation at the use site. Based solely on erosion concerns, it is unreasonable to expect a large area such as the 10 hectare EFED standard farm pond scenario watershed to be completely treated with prom eton ( i.e. , denuded of vegetation for a year or more).

In order to better characterize the potential exposures estimated by modeling

, a need exists for some kind of scientifically defensible estimate of the greatest percentage of a 10 h a watershed that could reasonably be expected to be treated with prometon for each of these uses. For example, these descriptions of the maximum spatial extent of prometon applications for the airports/landing field use might include the width of treated st rip adjacent to a runway, the dimensions of a typical runway, and how many runways could be expected to traverse an approximately 10 ha watershed draining an airport. Such information would allow the Agency to scale the estimated environmental concentratio ns (EECs) to the proportion of the watershed treated for aquatic exposure assessment purposes.

9.2 Ecological Effects Data

Table 9

- 2 provides ecologic al effects studies by MRID that offer data for each guideline requirement as well as study classifications a nd whether or not f urther data are needed to support the Registration Review ecological risk assessment ( i.e.

, whether there is a data gap).25 In addition to parent prometon, d egradates GS

- 11526 and GS

- 14626 will be considered stressors of concern in the Re gistration Review ecolo gical risk assessment. In the absence of data on the toxicity of GS

- 11526 and GS

- 14626 , the conservative TTR approach will be used for the stressors of concern.

Table 9

- 2. Registrant

- Submitted Ecological Effects Data for Prometon and Remaining Data Gaps

Guideline Description MRID/ Source Classification Data Gap?

850.1010 Acute toxicity freshwater invertebrates 41609109 Acceptable No

850.1025 850.1055 Acute toxicity estuarine/marine mollusk 41810901 Acceptable No

850.1035 850.1045 Acute toxicity estuarine/marine invertebrate 41609110 Acceptable No

850.1075 Acute toxicity freshwater fish (cold water species) 41609108 Acceptable No; however, given that the freshwater fish acute and chronic endpoints are approximately equal, additional data

– either an acute toxicity test with fathead minnow or a chronic test with rainbow trout

– are recommended. Acute toxicity freshwater fish (warm water species) 41609107 Acceptable

Acute toxicity estuarine/marine fish 41725301 Acceptable No

850.1300 Aquatic invertebrate life cycle (freshwater) 41810903 Acceptable No

850.1350 Aquatic invertebrate life cycle (saltwater) No data

-- Yes, aquatic invertebrate life cycle toxicity data for an estuarine/marine invertebrate are required under 40 CFR Part 158 if the product is expected to enter the environment in significant concentrations because of its expected use or mobility patterns.

850.1400 Fish early life

- stage (freshwater) 41810902 42318202 Acceptable No; however, given that the freshwater fish acute and chronic endpoints are approximately equal, additional data

– either an acute toxicity test with fathead minnow or a chronic test with rainbow trout

– are recommended.

Fish early life

- stage (saltwater) No data

-- Yes, early

- life stage toxicity data for an estuarine/marine fish are required under 40 CFR Part 158 if the product is expected to enter the environment in significant concentrations because of its expected use or mobility patterns.26 Guideline Description MRID/ Source Classification Data Gap?

850.2100 Avian oral toxicity (upland game or waterfowl species) 41609104 00079616 Acceptable Acceptable No

Avian oral toxicity (passerine species) No data

-- Yes, avian acute oral toxicity data for a passerine species are required under the new 40 CFR Part 158.

850.2200 Avian dietary toxicity (upland game species) 41609105 Acceptable No

Avian dietary toxicity (waterfowl species) 41606106 Acceptable No

850.2300 Avian reproduction (upland game species) 42132101 Acceptable No

Avian reproduction (waterfowl species) 42132102 Acceptable No

850.3020 Honeybee acute contact toxicity 41609115 Acceptable No

850.4100 Seedling emergence (terrestrial plants) 41725303 Acceptable No

850.4150 Vegetative vigor (terrestrial plants) 41725304 Acceptable No

850.4400 Aquatic plant growth (aquatic vascular plant toxicity) -- -- Yes, data for an aquatic vascular plant

– Lemna spp.

– are required under 40 CFR Part 158.

850.4500 Aquatic plant growth (aquatic non

- vascular plant: algal toxicity) 41725305 (green alga) Acceptable No

No data for freshwater diatom -- Yes, data for aquatic non

- vascular plant species including a freshwater diatom are required under 40 CFR Part 158.

No data for marine diatom -- Yes, data for aquatic non

- vascular plant species including a marine diatom are required under 40 CFR Part 158.

850.4550 Aquatic plant growth ( aquatic non

- vascular plant: cyanobacteria toxicity) No data

-- Yes, data for aquatic non

- vascular plant species including a cyanobacterium are required under 40 CFR Part 158. FW = freshwater; SW = saltwater

Submission of data to eliminate data gaps would reduce uncertainties in the ecological effects assessment. Data gaps have been assigned either a low or high potential to add value to the Registration Review risk assessment . While still considered data ga ps according to 40 CFR Part 158, low potential studies are unlikely to change risk determinations because alternate methods and weight of evidence may possibly be used in the absence of data. High potential studies would enable the Agency to better charac terize potential risks by eliminating uncertainties for27 both non

- listed and listed species that cannot be accounted for us ing alternate methods or weight of evidence.

Data from the following guideline studies are considered to have high potential to add v alue to the ecological risk assessment for prometon :

Guideline 850.1075

– Fish Acute Toxicity, fathead minnow or Guideline 850.1400

– Fish Early Life Stage Toxicity Test: The chronic, early life stage endpoint of 19.7 mg/L for freshwater fish (fathead min now; MRIDs 41810902, 42318202) is approximately equal to the most sensitive acute endpoint of 19.6 mg/L for freshwater fish (rainbow trout; MRID 41609108). This discrepancy is probably due to the differen t species used in the tests ( i.e. , fathead minnow i n the chronic test and rainbow trout in the acute test)

. Additional data

– either an acute toxicity test with fathead minnow or a chronic test with rainbow trout

– are recommended and considered to have a high potential to add value to the Registration Re view risk assessment because the data will allow the Agency to evaluate risk to fre shwater fish species. The data will also allow the Agency to generate an acute to chronic ratio (ACR) for evaluating risk to estuarine/marine fish species from chronic exposure to prometon. EFED Guidance recommends that acute and chronic toxicity values from the same species be used to calculate an ACR 14

. If an acute
tox icity endpoint for fathead minnow is submitted, a fathead minnow ACR will be applied to the most sensitive freshwater fish acute toxicity endpoint for prometon to generate a chronic toxicity endpoint for freshwater fish. In the absence of this data, the m ost conservative freshwater f ish ACR among the triazines may be applied to the most sensitive freshwater fish acute toxicity endpoint for prometon to generate a chronic toxicity endpoint for freshwater fish exposed to prometon

.

Guideline 850.2100

– Avian O ral T oxicity, passerine species: A cute oral toxicity data for a passerine species a re required under the new 40 CFR Part 158. No studies have been submitted for this data requirement. Given that the 200 8 RED (DP 335306) identified a risk concern for bir ds from acute and chronic exposure, fulfilling this data requirement has a high potential to add value to the Registration Review ecological risk assessment as the generated data will allow the Agency to be protective of passerine species. In the absence of this data, passerine toxicity data for surrogate pesticides

– starting with data for triazines and proceeding to data for less related chemicals

– may be used to characterize the toxicity of prometon to passerine species

.

Guideline 850.4400

– Aquatic Plant Toxicity Test Using Lemna spp.: Data for an aquatic vascular species ( Lemna spp.) are required under 40 CFR Part 158. In previous risk assessments, an ECOTOX open literature study (E081431) was referenced for characteriz ing the toxicity of prometon to aquatic vascular plants ( i.e.

, Lemna spp.). However, this study has been classified as qualitative for use in the Registration Review ecological risk assessment because of the lack of experimental details ( e.g. , replication , test concentrations) . Given that the 200 8 RED (DP 335306) identified a risk concern for aquatic vascular plants, fulfilling this data requirement has a high potential to add value to the Registration Review risk assessment. In the absence of this data, the most conservative Lemna toxicity endpoint s among the triazines may be used to characterize quantitatively the toxicity of prometon to aquatic vascular plant species

.

14 “Use of Acute

- to

- Chronic Ratios in Support of Ecological Risk Assessment of Pesticides.” EFED memo dated June 7, 2005.28 Guideline 850.4500

– Algal Toxicity & Guideline 850.4550

– Cyanobacteria ( Anabaena flos

aqua ) Toxicity: Data for aquatic non

- vascular plant species are required under 40 CFR Part 158. No studies have been submitted for a freshwater diatom ( e.g. , Navicula pelliculosa ), a marine diatom ( e.g. , Skeletonema costatum ), or a cyanobacterium (e. g., Anabaena flos

- aqua ). In previous risk assessments, an ECOTOX open literature study (E009211) was referenced for characterizing the toxicity of prometon to marine algae. However, this study has been classified as qualitative for use in the Registratio n Review ecological risk assessment because of the lack of experimental details ( e.g. , replication, test concentrations) . Given that the 200 8 RED (DP 335306) identified a risk concern for aquatic non

- vascular plants, fulfilling this data requirement has a high potential to add value to the Registration Review risk assessment.

A comparison of the toxicity endpoints for 4 marine alga species i n a previously

- cited open literature study (E009211) indicates that the tested species are 2.5 to 10 times less sensitive to prometon than the surrogate triazine atrazine. However, t here is some uncertainty associated with this comparison because of insuf ficient experimental details . A comparison of the toxicity endpoints from registrant

- submitted studies indicates that Selenastrum capricornutum is 2 times less sensitive to prometon (EC 50 = 0.098 mg/L, NOEC = 0.032 mg/L; MRID 41725305) than atrazine (EC 50 = 0.049 mg/L, NOEC = 0.016 mg/L; MRID 43074802) and confirms the toxicity relationship between prometon and atrazine for algae: algae tend to be less sensitive to prometon than atrazine. Since both of the registrant

- submitted studies have been clas sified as acceptable, this comparison of toxicity endpoints has less uncertainty associated with it than that of the open literature ECOTOX study. Therefore, in the absence of data for a freshwa ter diatom, marine diatom, and cyan o bacterium, a factor of 2 may be applied to the most conservative aquatic non

vascular plant endpoint s ( i.e. , EC 50 and N OEC) for atrazine to characterize quantitatively the toxicity of prometon to aquatic non

- vascular plants

. Data from the following guideline studies are considered to have low potential to add value to the ecological risk assessment for prometon :

Guideline 850.1350

– Mysid Chronic Toxicity Test: Aquatic invertebrate life cycle toxicity data for an estuarine/marine invertebrate are required under 40 CFR Part 158 if the product is expected to enter the environment in significant concentrations because of its expected use or mobility patterns. No studies have been submitted for this data requirement. Given that prometon is slightly toxic to aquati c animals on an acute basis, and there is no evidence to indicate that estuarine/marine animals are substantially more sensitive to prometon than freshwater animals, fulfilling this data requirement has a low potential to add value to the Registration Revi ew risk assessment. In the absence of this data, toxicity to estuarine/marine invertebrates from chronic exposu re to prometon may be characterized by appl ying an ACR generated from toxicity data for Daphnia to the acute toxici ty endpoint for mysid shrimp.

Guideline 850.1400

– Fish Early Life Stage Toxicity Test (Estuarine/Marine Species): Early life stage toxicity data for an estuarine/marine fish are required under 40 CFR Part 158 if the product is expected to enter the environment in significant concent rations because of its expected use or mobility patterns. No studies have been submitted for this data requirement. Given that prometon is slightly toxic to aquatic animals on an acute basis, and there is no evidence to2 9 indicate that estuarine/marine ani mals are substantially more sensitive to prometon than freshwater animals, fulfilling this data requirement has a low potential to add value to the Registration Review risk assessment. In the absence of this data, toxicity to estuarine/marine fish from c h ronic exposure to prometon may be characterized using toxicity data for freshwater fi sh exposed to prometon or toxicity data for estuarine/marine fish exposed to other triazines

.



### 10 References

DP 335306. Ecological Risk Assessment in Support of the Re

- regis tration Eligibility Decision for Prometon. August 31, 2007.

E000546. Bath, R., Ullmann, L., and Sachsse, K. 1973. Determination of pesticide toxicity to fish. Schriftenr. Ver. Wasser

- Boden

- Lufthyg. Berlin

- Dahlem. 37: 241

- 256. (English translation).

E 009211. Walsh, G.E. 1972. Effects of herbicides on photosynthesis and growth of marine unicellular algae. Hyacinth Control Journal 10: 45

- 48.

E081431. Drost, W., Backhous, T., Vassilakaki, Grimme, L.H. 2003. Mixture toxicity of s

triazines to Lemna min or under conditions of simultaneous and sequential exposure. Fresenius Environmental Bulletin. 12: 601

- 607.

E013154. Marchini, S., Passerinei, L., Cesareo, D., and Tosato, M.L. (1988). Herbicidal triazines: Acute toxicity on Daphnia , Fish, and Plants and analysis of its relationships with structural factors. Ecotoxicology and Environmental Safety. 16: 148

- 157.

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 D.C. January 23, 2004.

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



### 11 Bibliography of Cited MRIDs

Fate Studies

000 22737 Corbin, F.T. (1965) The Influence of pH on t he Detoxification of Her bicides in Soil. (Unpublished study received Aug 30, 1965 under 6F0466; prepared by North Carolina State Univ., Dept. of Crop Science, submitted by Velsicol Chemical Corp., Chicago, Ill.; CDL:090517

- AE)

000 27134 Talbert, R.E.; Fle tchall, O.H. (1965) The adsorption of some s

- Triazines in soils.30 Weeds 13(? ):46

- 52. (Also i n unpublished submission received Jul 19, 1978 under 201

- 403; submitted by Shell Chemical Co., Washington, D.C.; CDL:234472

- J)

000 28395 Corbin, F.T.; Upchurch, R.P. (19??) Influence of pH on detoxi fi cation of herbicides in soil. Weeds 15(4):370

- 377. (Also In unpub lished submission received Jan 5, 1968 under 8F0725; submitted by Velsicol Chemical Corp., Chicago, Ill.; CDL:091252

- AL)

000 41353 Gerber, H.R.; Ziegle r, P.; Dubach, P. (1970) Leaching as a tool in the evaluation of herbicides. Proceedings of the British Weed Conference 10:118

- 125. (Also i n unpublished submission received Mar 8, 1976 under 201

- 379; submitted by Shell Chemical Co., Washington, D.C.; CDL:2 23590

- S)

000 55090 Weber, J.B.; Perry, P.W.; Upchurch, R.P. (1965) The influence of temperature and time on the adsorption of Paraquat, Diquat, 2,4

- D and Prometone by clays, charcoal, and an anion

- exchange resin. Soil Science Society of America Proceeding s 29:678

- 688. (Also i n unpublished submission received Apr 7, 1971 under unknown admin. no.; submitted by Chevron Chemical Co., Richmond, Calif.; CDL:180000

- F)

000 65619 Weber, J.B.; Weed, S.B. (1968) Adsorption and desorption of diquat, paraquat, and pro metone by montomorillanitic and kaolinitic clay minerals. Soil Science Society of America Proceedings 32:485

- 487. (Also i n unpublished submission received Aug 22, 1977 un

- der 239

- 1663; submitted by Chevron Chemical Co., Richmond, Calif.; CDL:231430

- T)

000 65621 Weber, J.B.; Perry, P.W.; Upchurch, R.P. (1965) The influence of temperature and time on the adsorption of paraquat, diquat, 2,4

- D and prometone by clays, charcoal, and an anion

- exchange resin. Soil Science Society of America Proceedings 29(6):678

- 688. (Also i n unpublished submission received Aug 22, 1977 un

- der 239

- 1663; submitted by Chevron Chemical Co., Richmond, Calif.; CDL:231430

- V)

000 75705 Holly, K.; Roberts, H.A. (1963) Persistence of phytotoxic residues of triazine herbicides in soil. Weed Research 3(? ):1

- 10. (Al

- so in unpublished submission received Jul 19, 1978 under 201

- 403; submitted by Shell Chemical Co., Washington, D.C.; CDL: 234476

- AI)

00 114837 Corbin, F. (1965) The Influence of p H on the Detoxification of Herbi cides in Soi l. Doctoral thesis, North Carolina State Univ., Dept. of Crop Science. (Unpublished study received Mar 18, 1976 under 3E1385; submitted by U.S. Dept. of Interior, Bureau of Reclamation, Washington, DC; CDL:095210

- N)

00 121317 Weber, J.; Weed, S. (1968) Adsorption and Desorption of diquat, paraquat, and prometone by montmorillonitic and kaolinitic clay minerals. Soil Science Society of America Proceedings 32:485

- 487. (Also In unpublished submission received Dec 21, 1982 under 2 39

- 2247; submitted by Chevron Chemical Co., Richmond, CA; CDL:249102

- T)

00 125922 Guth, J. (1976) Leaching Model Study with the Herbicide Prometon in Four31 Standard Soils: Project Report 31/76. (Unpublished study received Feb 13, 1978 under 100

- 544; prepar ed by Ciba

- Geigy, Ltd., Switz., submitted by Ciba

- Geigy Corp., Greensboro, NC; CDL:232980

- F)

00 125923 Halama, P.; Balu, K.; Hofberg, A. (1972) Photolysis of Prometone in Aqueous Solution under Natural and Artificial Sunlight Conditions: Report No. 72127

. (Unpublished study received Feb 13, 1978 under 100

- 544; submitted by Ciba

Geigy Corp., Greensboro, NC; CDL:232980

- G)

00 125924 Nixon, W. (1977) Letter sent to J. Ross dated May 27, 1977: Hy drolysis of Prometon. (Unpublished study received Feb 13, 1978 u nder 100

- 544; submitted by Ciba

- Geigy Corp., Greensboro, NC; CDL:232980

- H)

00 125926 Smith, K. (1977) [ delta ] 14C

- Promet on Soil Metabolism Study: Labo ratory Nos. 6E

- 2417, 6E

- 2419, 6E

- 2420. (Unpublished study re ceived Feb 13, 1978 under 100

- 544; prepared by Cannon Labora tories, Inc., submitted by Ciba

- Geigy Corp., Greensboro, NC; CDL:232980

- J)

00 125927 Smith, K. (1977) [ delta ] 14C

- Prometon Residue Study in Bluegill Sun

- fish under Dynamic Flow Exposure Conditions: Laboratory No. 6E

- 2421. (Unpublished study received Feb 13, 1978 under 100

- 544; prepared by Cannon Laboratories, Inc., submitted by Ciba

- Geigy Corp., Greensboro, NC; CDL:232980

- K)

00 125928 Smith, K. (1977) [ delta ] 14C

- Prometon Soil Parent Leaching Study: Laboratory No. 6E

- 2422. (Unpublished study received Feb 13, 1978 under 100

- 544; prepared by Cannon Laboratories, Inc., sub mitted by Ciba

- Geigy Corp., Greensboro, NC; CDL:232980

- L)

00 125929 Smith, K. (1977) [ delta ] 14C

- Prometon Soil Aged Leaching Study: Laboratory No. 6E

- 2423. (Unpublished study received Feb 13, 1978 under 100

- 544; prepared by Cannon Laboratories, Inc., sub

- mitted by Ciba

- Geigy Corp., Greensboro, NC; CDL:232980

- M)

00 125930 Smith, K. (1977) Catfish Bioa ccumulation during Exposure to delta 14C

Prometon in a Soil/Water/Fish Ecosystem: Laboratory No. 7E

- 5792. (Unpublished study received Feb 13, 1978 under 100

- 544; prepared by Cannon Laboratories, Inc., submitted by Ciba

- Geigy Corp., Greensboro, NC; CDL :232980

- N)

00 125931 Smith, K. (1977) Prometon Hydrolysis Study: Laboratory No. 7E

- 6516. (Unpublished study received Feb 13, 1978 under 100

- 544; prepared by Cannon Laboratories, Inc., submitted by Ciba

- Geigy Corp., Greensboro, NC; CDL:232980

- O)

00 12771 1 Weber, J. (19??) Leachability of Atrazine, Buthidazole, Bromacil, Diuron, Diphacinone, and Prometon through a Lakeland Sand. (Un published study received Aug 21, 1978 under 876

- EX

- 36; prepared by North Carolina State Univ., submitted by Velsicol Chemical Corp., Chicago, IL; CDL:234819

- G)

00 127713 Weber, J. (19??) Adsorption and Characterization of Diphacinone and Prometon32 on Lakeland Sand, Alama nce Silt Loam, Ca

- montmorillon ite, and Acidic Soil Organic Matter. (Unpublished study re ceived Aug 21, 1978 und er 876

- EX

- 36; prepared by North Carolina State Univ., submitted by Velsicol Chemical Corp., Chicago, IL; CDL:234819

- I)

00 134841 Weber, J.; Swain, L. (19??) Report to ...: Leachability of Atzra zine, Buthiazole, Bromacil, Diuron, Diphacinone and Prometon t hrough a Lakeland Sand. (Unpublished study received Jul 12, 1978 under 876

- EX

- 35; prepared by N.C. State Univ., submitted by Velsicol Chemical, Corp., Chicago, IL; CDL:234423

- I)

00 134843 Weber, J.; Swain, L. (19??) Report to ...: Adsorption and Charac ter ization of Diphacinone and Prometon on Lakeland Sand, Ala mance Silt Loam, Ca

montmorillonite and Acidic Soil Organic Mat

- ter. (Unpublished study received Jul 12, 1978 under 876

- EX

- 35; prepared by N.C. State Univ., submitted by Velsicol Chemical, Corp., Ch icago, IL; CDL:234423

- K)

00 146155 Hazleton Laboratories America, Inc. (1985) Hydrolysis of Prometon: Study No. 6015

- 165. Unpublished study 19 p.

00 146156 Hazleton Laboratories America, Inc. (1985) Aqueous Solution Photol ysis of Prometon: Interim Rep ort: Study No. 6015

- 163. Unpub lished study. 24 p.

00 146157 Hazleton Laboratories America Inc. (1985) Artificial Sunlight Pho todegradation of Prometon on Soil: Interim Report: Study No. 6015

- 162. Unpublished study. 33 p.

00 146158 Hazleton Laboratories A merica Inc. (1985) The Adsorption/Desorption of Radiolabeled Prometon on Representative Agricultural Soils: Study No. 6015

- 164. Unpublished study. 48 p.

00 146159 Hazleton Laboratories America Inc. (1985) Mobility Determination of Prometon in Soils by Soi l Thin Layer Chromatography: Study No. 6015

- 167. Unpublished study. 53 p.

00 146160 Hazleton Laboratories America Inc. (1985) Leaching Characteristics of Parent Prometon: Interim Rep ort: Study No. 6015

- 201. Unpub lished study. 27 p.

00 148344 Harris, C. ( 1966) Adsorption, movement, and phytotoxicity of monuron and s

Triazine herbicides in soil. Weeds 14:6

- 10.

00 162534 Balcomb, R.; Honeycutt, R. (1986) Fi eld Dissipation Studies on Pro meton (Pramitol 25E)(Fresno, Ca ): Rept. No. EIR

- 86013. Unpub lished study prepared by Ciba

- Geigy Corp. 161 p.

00 162535 Balcomb, R.; Honeycutt, R. (1986) Fi eld Dissipation Studies on Pro meton (Pramitol 25E) (Columbia, New York): Rept. No. EIR

- 86014. Unpublished study prepared by Ciba

- Geigy Corp. 172 p.

00 162536 Balcomb, R.; Honeycutt, R. (1986) Fi eld Dissipation Studies on Pro meton (Pramitol 25E)(York, Nebraska): Rept. No. EIR

- 86018. Un

- published study33 prepared by Ciba

- Geigy Corp. 211 p.

40145501 Obrist, J. (1987) Aerobic/Anaerobic and Sterile Soil Metabolism of Prometon: Laboratory Study No. 6015

- 309. Unpublished study prepared by Hazleton Laboratories America, Inc. 110 p.

40225801 Puhl, R. (1987) Aqueous Solution Photolysis of Prometon: Laboratory Study No. 6015

- 163. Unpublished study prepared by Hazleton L ab

- oratories America, Inc. 45 p.

40225802 Puhl, R. (1987) Artificial Sunlight Photodecomposition of Prometon on Soil: Laboratory Study No. 6015

- 162. Unpublished study pre

- pared by Hazleton Laboratories America, Inc. 49 p.

40225803 Blair, J. (1986) Le aching Characteristics of Parent Prometon: Lab

- oratory Study No. 6015

- 201. Unpub lished study prepared by Hazle ton Laboratories America, Inc. 53 p.

41114801 Das, Y. (1989) Hydrolysis of [Triazine( U)

- carbon 14] |Prometon in Aqueous Solutions Buffered at pH 5, 7 and 9: Proj. No. ISSI No. 89010. Unpublished study prepared by Innovative Scientific Services, Inc. 76 p.

41114802 Das, Y. (1989) Photo degradation of Triazine(U)

- carbon 14|Prometon on Soil Under Artificial Sunlight: Proj. No. ISSI No. 89021. Unpublished study prepared by Innovative Scientific Services, Inc. 124 p.

42144603 Matt, F. (1988) The Adsorption and Desorption of [Carbon 14] Pro meton on Representative Agricultu ral Soils: Final Repo rt: Labor atory Project ID: HLA 6117

- 139. Unpublished study prepared by Hazleton Laboratories America, Inc. 69 p.

42313501 Gohdes, M. (1992) Aerobic, Aerobic/Anaerobic, and Sterile Soil Metabolism of [ carbon 14 ]

- Prometon: Lab Project Number: HLA 6117

- 147. Unpublished study prepared by Hazleton Laboratories America, Inc. 240 p.

92149013 Schabaker, D. (1990) Ciba

- Geigy Corp. Phase 3 Summary of MRID 41114801. Hydrolysis of [Triazine (U)

- Carbon

- 14] Prometon in Aqueous Solutions Buffered at pH 5,7,9: Projec t 89010; ISSI No. 89010. Prepared by INNOVATIVE SCIENTIFIC SERVICES, INC. 13 p.

92149014 Schabacker, D. (1990) Ciba

- Geigy Corp. Phase 3 Summary of MRID 40225801. Aqueous Solution Photolysis of Prometon: HLA Project No. 6015

- 163. Prepared by HAZLETON LABS . AMERICA, INC. 14 p.

92149016 Schabacker, D. (1990) Ciba

- Geigy Corp. Phase 3 Summary of MRID 41114802. Photodegradation of [Triazine( U)

- carbon

- 14] Prometon on Soil under Artificial Sunlight: ISSI No. 89021. Prepared by Innovative Scientific Services, Inc. 19 p.

92149017 Schabacker, D. (1990) Ciba

- Geigy Corp. Phase 3 Summary of MRID 40225803. Prometon

- Leaching Study: Project 6015

- 201 . Prepared by HAZLETON LABS. AMERICA, INC. 18 p.34 92149018 Schabacker, D. (1990) Ciba

- Geigy Corp. Phase 3 Summary of MRID 92149021. The Adsorption and Desorption of [Carbon

- 14] Prometon on Representative Agricultural Soils: HLA 6117

- 139. Prepared by Hazle ton Laboratories America, Inc. 12 p.

Ecological Effects Studies

00079616 Fink, R. (1976) Final Report: Acute Oral LD50

-- Mallard Duck: Project No. 108

- 122. (Unpublished study received Sep 15, 1977 under 100

- 544; prepared by Wildlife International, Ltd., submitted by Ciba

- Geigy Corp., Greensboro, N.C.; CDL:231814

- H)

41609104 Campbell, S. (1990) Prometon: An Acute Toxicity Study with the Northern Bobwhite: Lab Project Number: 108

- 326. Unpublished study prepared by Wildlife International Ltd. 22 p.

41609105 Long, R. (1990) Prometon: A Dietary LC50 Study with the Northern Bobwhite: Lab Project Number: 108

- 324. Unpublished study pre

- pared by Wildlife International Ltd. 52 p.

41609107 Murphy, D. (1990) Prometon: A 96

- hour Static Acute Toxicity Test w ith the Bluegill ( Lepomis macrochirus ): Lab Project Number: 108A

- 103A. Unpublished study prepared by Wildlife International Ltd. 49 p.

41609108 Murphy, D. (1990) Prometon: A 96

- hour Static Acute Toxicity Test with the Rainbow Trout ( Oncorhynchus mykiss ): Lab Project Number: 108A

- 102B. Unpublished study prepared by Wildlife International Ltd. 49 p.

41609109 Bellantoni, D. (1990) Prometon: A 48

- hour Static Acute Toxicity Test with the Cladoceran ( Daphnia magna ): Lab Project Number: 108A

- 101. Unpublished study prepared by Wildlife International Ltd. 50 p.

41609110 Murphy, D. (1990) Prometon: A 96

- hour Static Acute Toxicity Test with the Saltwater Mysid ( Mysidopsis bahia ): Lab Project Number: 108A

- 105A. Unpublished study prepared by Wildlife Internationa l Ltd. 50 p.

41609111 Murphy, D. (1990) Prometon: A 96

- hour Static Acute Toxicity Test with the Sheepshead Minnow ( Cyprinodon variegatus ): Lab Project Number: 108A

- 104. Unpublished study prepared by Wildlife Inter

- national Ltd. 51 p.

41609115 Hoxter , K. (1990) Prometon: An Acute Contact Toxicity Study with the Honey Bee: Lab Project Number: 108

- 323. Unpublished study prepared by Wildlife International Ltd. 16 p.

41725301 Murphy, D. (1990) A 96

- Hour Static Acute Toxicity Test with the Sheepshead Min now ( Cyprinodon variegatus ): Amended Report to: Lab Project Number: 108A

- 104. Unpublished study prepared by Wildlife International Ltd. 52 p.

41725303 Chetram, R. (1990) Tier 2 Seedling Emergence Nontarget Phytotoxicity Study Using Prometon Technical: La b Project Number: LR90

- 05. Unpublished study35 prepared by Pan

- Agricultural Laboratories. 274 p.

41725304 Chetram, R. (1990) Tier 2 Vegetative Vigor Nontarget Phytotoxicity Study Using Prometon Technical: Lab Project Number: LR90

- 03. Unpublished study prep ared by Pan

- Agricultural Laboratories, Inc. 224 p.

41725305 Hughes, J. (1990) The Toxicity of Prometon to Selenastrum capricornutum : Lab Project Number: B267

- 47

- 1. Unpublished study pre

- pared by Malcolm Pirnie, Inc. 33 p.

41810902 Peters, G. (1991) An Early Life

- Stage Toxicity Test with the Fathead Minnow ( Pimephales promelas ): Lab Project No: 108A

- 115A. Unpublished study prepared by Wildlife International Ltd. 47 p.

41810901 Ward, T. (1991) Acute Flow Through Mollusc Shell Deposition Test with Prometon: Lab Project Number: 9113

- CG. Unpublished study prepared by Resource Analysts, Inc., Envirosystems Div. 36 p.

41810903 Peters, G. (1991) A Flow

- through Life

- cycle Toxicity Tes t with the Cladoceran ( Daphnia magna ): Lab Project Number: 108A

- 114E. Un published study prepared by Wildlife International Ltd. 49 p.

42132101 Beavers, J. (1991) Prometon: A One

- Generation Reproduction Study with the Bobwhite ( Colinus virginianus ): Lab P roject Number: 108

- 318. Unpublished study prepared by Wildlife International Ltd. 141 p.

42132102 Beavers, J. (1991) Prometon: A One

- Generation Reproduction Study with the Mallard (Anas platyrhynchos): Lab Project Number: 108

- 319. Unpublished study
prepa red by Wildlife International Ltd. 142 p.

42318202 Graves, W.; Peters, G. (1992) A Supplement to an Early Life

- Stage Toxicity Test with the Fathead Minnow ( Pimephales Promelas ). Unpublished study prepared by Ciba

- Geigy Corp. 19 p.36 

### Appendix A: SIP (v 1.0) Inputs and Results

The purpose of this model is to provide an upper bound estimate of exposure of birds and mammals to pesticides through drinking water alone. This model is intended for use in problem formulation to determine whether or not drinki ng water exposure alone is a potential pathway of concern. This does not aggregate drinking water exposure with other exposure routes (i.e., diet, inhalation, dermal).

Assumptions:

SIP employs the following conservative assumptions to derive upper bound exposure estimates:

1) The chemical concentration in drinking water is at the solubility limit in water (at 25 o C). 2) The assessed animals obtain 100% of their daily water needs through drinking water. 3) The daily water need is equivalent to the daily water flux rate as calculated by Nagy and Peterson (1988). 4) The body weight of the assessed bird is equivalent to the smallest generic bird modeled in T

- REX (i.e., 20 g). This assumption results in the highest ratio of exposure to toxicity for the 3 assessed avian body weights of T

- REX (i.e., 20, 100, 1000 g). 5) The body weight of the assessed mammal is equivalent to the largest generic mammal modeled in T

- REX (i.e., 1000 g). This results in the highest ratio of exposure to toxicity for the 3 ass essed mammalian body weights of T

- REX (i.e., 15, 35, 1000 g).

Table 1. Inputs Parameter Value Chemical name prometon Solubility (in water at 25 o C; mg/L) 620

Mammalian LD 50 (mg/kg

- bw) 1518 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg

- bw) 20 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species NOTE: This endpoint is

non

- definitive. However, use of the definitive endpoint of 3157 mg/kg

- bw for mallard duck yields the same results. Avian LD 50 (mg/kg

- bw) 2264 Avian test species northern bobwhite quail Body weight (g) of "other" avian species Mineau scaling factor 1.15

Mallard NOAEC (mg/kg

- diet) 50 Bobwhite quail NOAEC (mg/kg

- diet) 175 NOAEC (mg/kg

- diet) for other bird species Body weight (g) of other avian species NOAEC (mg/kg

- diet) for 2nd other bird species Body weight (g) of 2nd other avian species37 Table 2. Mammalian Results Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 106.6400 106.6400 Adjusted toxicity value (mg/kg

- bw) 1167.5857 15.3832 Ratio of exposure to toxicity 0.0913 6.9322

Conclusion* Drinking water exposure alone is NOT a potential

concern for mammals Exposure through drinking water alone is a

potential concern for mammals

Table 3. Avian Results Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 502.2000 502.2000 Adjusted toxicity value (mg/kg

- bw) 1631.0524 2.4806 Ratio of exposure to acute toxicity 0.3079 202.4487

Conclusion* Exposure through drinking water alone is a

potential concern for birds Exposure through drinking water alone is a

potential concern for birds

*Conclusion is for drinking water exposure alone. This does not combine all routes of exposure. Therefore, when aggregated with other routes ( i.e ., diet, inhalation, dermal), pesticide exposure through drinking water may contribute to a total exposure that has potential fo r effects to non

- target animals.