### UNITED STA TE S ENV I RONMENTAL P ROTECT I ON AGENC Y WAS HI NGTO N

. D.C. 20460

O FFICE OF CHEM I CAL S A FETY A N O PO L LUTI ON P REVE N TIO N



### M EM ORA N D UM 

### D a t e: June 9, 2015 P C C od e : 

### 129122 DP Bar co dc: 

### 04 24568

SU BJ E CT:

F RO M:

REVI E W E D BY :



### THRO U GH:



### TO : R eg i s trati on R ev iew: Probl em Formulation fo r Environmental Fate, Ecological Ri sk and Enda n ge red Species for Diclosulam

Mary C lock-Rust
,

# Bi**ologis ~CJA-**  

# --g-.**~** 

### Jim Car l eton. Ph.D., Senior Scientist Environmen t a l Risk Bran c h IV Enviro nm enta l Fa te and Effects Division (7507 P)

Chery l S utt o n , Ph.D.
, E nvironm e nta l Scientist Thomas Steeger
, Ph.D.
, Senior Scie n ce Adv i so r Environmental Risk Branch IV E n vironmental Fate and Effec t s Division (7507 P ) 

# (;,/<1/ 1 S

Jean H olmes, DVM
, MPH. Branch Ch ief

# (l,,A~**~ ~~**  / 

# J 

# ,r

E nvir o nm e nta l Ri s k Bran c h IV

# ~,- Environmenta l Fate and E ff ec t s Divis i on (7507P)

Matthew Manupclla, C h em i ca l Review Manager Risk Management and Impl emen t ation Branch 2 Pesticide Re-Evaluation Di v ision (7508P)

The E n v ironm enta l fate and Effects Divi sion (EfEO) has completed th e preliminary problem fonnulation (a ttach ed) for th e eco logical ri sk, e nvironm e nta l fate and enda n ge red s pecie s

assess ments to be conducted as part of th e Re g i s tration Review of the h e rbicid e diclosu l am ( P C Code: 1 29 1 22). The problem formu l ation draws o n informat i on from both ope n l iterature a nd studies sub mitt ed by the technical r egistra nt s in r es p o n se to data requirements. An updated drinking water asses s ment has been completed fo r dic l osu l a m 1 • 

### This document is intended to provide an over v iew of what is curre ntl y known regarding the e n vironmental fate and eco l og i cal effects associated with d i closulam and its degradates, a nd out lin es uncertainties regarding attributes of the parent compound and it s transformation products. 

### It describes the preliminary

eco l ogica l risk h ypot h es i s and the processes that w i ll be used during th e comp l et ion of

### environmental fate and ecologi cal risk assessments in support of R egistration R eview. This

document also recommends studies that should be included in a data call

- in (DCI) to address uncertainties surrounding the environmental fate and potential ecolo gical effects of diclosulam

.

It i s noted that diclosulam labels contain an error in the application rate for soybeans. The labels inaccurately state that the application rate is 6 oz . per acre , rather than the correct rate of 0.6 oz

. per acre (0.0315 lb a.i./acre/year)

. Email corresponde nce to OPP’s Registration Division (RD) from the registrant has confirmed that the 6 oz./A soybean application rate is in error, ( though this correspondence did not affirm the correct rate )

. In the same email, t he registrant also indicated that although d iclosulam is registered for use on soybeans, there is currently no actual

us ag e on this crop with in the U.S. 1



### . Consistent with this assertion
, the Biological and Economic Analysis Division ( BEAD ) has informed EFED that no information or usage data exist w hich would suggest that diclosulam is actually used on soybean fields 2 

### in the U nited S tates

.

It should be noted that the Strongarm® label for diclosulam do es not list a maximum number of applications per year or the retreatment interval for peanuts.

1 Email correspondence between Jenn Hughes/Dow and Susan Bartow/OPP. 2/12/15.
2 US EPA, 2014.

### 2



# Problem Formulation for the Environmental Fate and Ecological Risk and

Endangered Species in Support of the Registration Review of

Diclosulam

Diclosulam (CAS Number 145701

- 21

- 9 )

Prepared by: Mary Clock

- Rust, Biol ogist Jim Carleton, Ph.D., Senior Scientist U. S. Environmental Protection Agency Office of Pesticide Programs Environmental Fate and Effects Division Environmental Risk Branch IV 1200 Pennsylvania Ave., NW Mail Code 7507P Washington, DC 20460 Reviewed by : 

### Cheryl Sutton, Ph.D., Environmental Scientist T homas Steeger, Ph.D., Senior Science Advisor

Approved by : Jean Holmes, DVM, MPH, Branch Chief

June 9 , 2015

### 3



# 1. Executive S ummary

The Environmental Fate and Effects Division (EFED) has completed the preli minary problem formulation (attached) for the ecological risk, environmental fate, endangered species, and drinking water assessments to be conducted as part of the R egistration R eview of diclosulam

. Th is problem formulation describes the methods to be use d during the completion of drinking water and ecological r isk assessments in support of R egistration R eview
, and provide s an

ove rview of the environmental fate, ecological effects , and potential risks associated with the use of diclosulam as well as uncert ain ties unique to risk assessment of diclosulam . This document also identifies additional studies that would be beneficial to the conduct of an ecological risk
assessment.

Ecological Effects Data G aps I nclude: 850.2300 Avian Reproduction Toxicity with m allard ducks ( Anas platyrhnchus ) 850.1350 Invertebrate Lifecycle Toxicity test with a marine/estuarine invertebrate species 850.1400 Fish Early Life Stage Toxicity Test with a marine/estuarine fish species 850.1400 Fish Early Life Stage Toxicity Test with a freshwater fish species

EFED recommends that additional data be requested to allow for a more comprehensive evaluation of potential effects to honey bees, consistent with Guidance for Assessing Pesticide Risks to Bees (USEPA et al. , 2014). These studie s include:

Non

- Guideline Tier 1 Pollinator Toxicity Data 3



### o Honey bee adult acute oral toxicity using TGAI ( e.g ., OECD 213 4 

### )

o Honey bee larvae acute oral toxicity using TGAI ( e.g ., OECD 237 5



### , protocol required )

o Honey bee adult chronic oral toxicit y (protocol required)

o Honey bee larvae chronic oral toxicity (protocol required)

o H oney bee semi

- field (tunnel or colony feeding) test

– TEP (protocol required)

o Field trial of residues in p ollen and nectar

– TEP (protocol required)

o Field tes ting for pollinators

– TEP (850.3040; protocol required)

In the absence of data, EFED will be unable to complete a risk assessment for terrestrial invertebrates (specifically, insect po llinators). Exposure may occur as a result of diclosulam uses through contact ( e.g ., for soil

- dwelling bees) and through ingestion of residues on plants treated with diclosulam.

3 http://www2.epa.gov/sites/production/files/2014

- 06/documents/pollinator_risk_assessment_guidance_06_19_14.pdf

4 OECD. 1998. OECD Guidelines for the Testing of Chemicals. Honeybees, Acute Oral Toxicity Test. OECD/OCDE 213 Adopted: 21 st September 1998. http://www.oecd

ilibrary.org/docse rver/download/9721301e.pdf?expires=1395850163&id=id&accname=guest&checksum=DA5C05C00A6B947E222C562C20D 9EDA1 (last accessed 04 / 15 /1 5 )
5 OECD. 2013. OECD Guidelines for the Testing of Chemicals. Honey bee ( Apis mellifera ) larval toxicity test, single expo sure. OECD/OCDE 237 Adopted 26 July 2013. http://www.oecd

ilibrary.org/docserver/download/9713171e .pdf?expires=1395849980&id=id&accname=guest&checksum=486E98B9ADBE06C29723801743480 A3B (last accessed 04/15/15 )

### 4

Also, i n the February 2000 assessment 6



### , co

- location data were required for endangered plant s grown in areas where soybeans and peanuts are grown

.

Environmental Fate Data Gaps Include: 835.4100 Aerobic Soil Metabolism ; test substance diclosulam, data needed on one (or more) additional soil s , with characterization of unextracted residues.



# 2. I ntroduction

Diclosulam (N

- (2,6

- dichlorophenyl)

- 5

- ethoxy

- 7

- fluoro[l,2,4]triazolo

- [l,5

- c] pyrimidine

- sulfonamide ; CAS No. 145701

- 21

- 9 ) is a n herbicide used to control broadleaf weeds in soybeans and peanuts. Its mode of action in plants is inh ibition of acetolactate synthase (ALS), an enzyme common to the biosynthesis of branch

- chain amino aci ds (Whitcomb
, 1999 7 

### ). Diclosulam can be absorbed by plant roots and foliage ; thus , the chemical is considered systemic

. Plant growth is inhibited within 2 hours following treatment 2



### . While cell division and growth are rapidly inhibited , plant death can be protracted

. Diclosulam is marketed by Dow AgroSciences under the trade name Strongarm ® 

### (84% a.i.)

, 

### which is formulated as water dispersible granules i n water soluble packets.

EFED evaluated the most recent ly completed ecological risk assessments for diclosulam
, along with currently available toxicity, exposure, and usage

- related information to determine if sufficient data are available
, or whether furt her updates are needed to support R egistration Review. Past risk assessments have include d a Section 3 Registration for the use of diclosulam

on soybeans and peanut s 3 

### . In addition, EFED considered the latest Agency science policies and risk assessment me thodologies. The structure of diclosulam , as well as the chemical names and other identifiers can be found in Table 4

.



# 3. Use Characterization

Diclosulam was initially registered for use on soybeans and peanuts in 2000. In March 2000, the Agency completed a screening

- level ecological risk assessment (USEPA, 2000) in support of the Section 3 Registration on soybeans and peanuts. There are 24(c) Special Local Needs (SLN) registrations indicating a special local need for diclosulam to control tropical spider wort in peanut in Georgia, Florida and Mississippi as well as on cottonwood plantations in Missouri and Tennessee

. No additional uses of diclosulam have been registered since completion of the Section 3 registration. According to the BEAD Chemical Profil e for Registration Review ( USEPA, 2014), although the chemical is registered for use on both peanuts and soybeans, usage between at least 2000

- 2012 was limited to application on peanuts, with an average of 4,000 lb a.i. applied annually in the U.S., primar ily in the states of Georgia and Alabama. Details regarding the two registered diclosulam uses are given in Table 1

.

6 US EPA, 2000 7 Whitcomb, C.E., 1999. An Introduction to ALS

- inhibiting herbicides. Toxicology and Industrial Health 15 (1

- 2); 231

- 239.

### 5

The single formulated product containing diclosulam is Strongarm ® 

### herbicide (84% a.i.; EPA Reg. No. 62719

- 287 ), which is packaged in wa ter

- soluble packets. Diclosulam labels state that a single pre

- plant application is allowed on soybeans, but on peanuts, pre

- plant and post

emergence applications are allowed.

The maximum application rate s (both single and annual) are 0.0315 lb a.i./ac re for soybeans (0.6 oz Strongarm ® 

### / acre) and 0.0236 lb a.i./acre for peanuts (0.45 oz Strongarm ® 

### / acre) , applied by ground only. It is noted that diclosulam labels contain an error in the stated application rate for soybeans : they state that the allowable application rate is 6 oz . per acre , rather than the 0.6 oz

. per acre that would correspond with the label maximum of 0.0315 lb a.i./acre

. Email correspondence between OPP’s Registration Division and the registrant has confirmed that this soybean applicati on rate is i n error (though to EFED’s knowledge this correspondence did not acknowledge what should be the correct rate
, i.e

. 0.6 oz Strongarm ® 

### /acre) . The registrant has also indicated that although diclosulam is registered for use on soybeans, there is n o current

us ag e on this crop 8 

### in the U.S

. BEAD has confirmed that no information or usage data exist to suggest that diclosulam is used on U.S. soybean fields.

Table 1 . Methods and rates of application of currently registered uses of diclosulam

.

Use Scen ario Application Type Maximum

Single Application Rate (lbs a.i./A) Maximum #

of apps/yr RTI

(days) Maximum

Annual Application Rate (lbs a.i./A) Peanuts Ground 0.0236 NS 1 NS 1 0.0236 Soybeans Ground 0.0315 1 NA 0.0315

1 Not stated: f

or peanuts no maximum number of applications or minimum retreatment interval are given on the label. For modeling, a single application per year at the maximum rate was assumed.



### The chemical profile produced by the Office of Pesticide Programs’ Biological and Economic Analy sis Division ( BEAD )
, lists the use patterns of maxim um exposure s for the current uses of diclosulam 9



### . For assess ing potential risks to non

- target taxa , EFED will use the application scenarios that result in maximum exposure for a given use. Any absence o f information on the labels that specifies the maximum single application rate, the application interval, the annual maximum rate allowed (lbs a.i./year), or application method may result in conservative assumptions

.



# 4. C onclusions from Previous Risk Assessm ents

In February, 2000, EFED completed a n environmental fate and ecological risk assessment for diclosulam as part of the Section 3 new chemical registration (USEPA 2000) 10



### . At maximum

8 Email correspondence between Jenn Hughes/Dow and Susan Bartow/OPP. 2/12/15.
9 US EPA, 2014. BEAD Chemical Profile (BCP) for Registration Review: Diclosulam . 12/12/2014.
10 US EPA, 2000. EFED Risk Assessment for Section 3 Registration of Diclosulam. 2/29/2000.

### 6

application rates on diclosulam labels, risks were identified for list ed and non

- listed species of terrestrial plants.

The likelihood of direct adverse effect s to birds, mammals, fish and aquatic invertebrates from acute exposure to diclosulam was considered to be low

. The likelihood of adverse effects to mammals from chr onic exposure to diclosulam was also expected to be low

. C hronic risk to birds wa s judged to be possible (eggshell thinning was observed in mallard ducks at all of the dietary test levels ) ; however, the relevant study failed to establish a definitive chro nic toxicity estimate ( data to address this deficiency were re commended by EFED in 2000
, but have not yet been submitted ). The p otential for adverse effects to freshwater fish, marine/estuarine fish and marine/estuarine invertebrates was uncertain
, since chronic toxicity data were not available for these taxa at the time the Section 3 assessment was completed

.

There have been no additional ecological risk assessments conducted on diclosulam since 2000, nor have new environmental fate or ecological effects data been submitted by the registrant in support of the registered uses on peanuts and soybean. In 2003, diclosulam was the subject of a United States Supreme Court decision (No. 03

- 388, Dennis Bates, et. al., petitioners v. Dow Agrosciences, LLC). The S upreme Court ruled that citizens damaged by pesticides have the right to sue companies of these toxic products, saying that federal pesticide law does not offer adequate protection from “manufacturers of poisonous substances.”



# a. Ecological Risk Assessment

EFED conducted a n environmental fate and ecological risk assessment on diclosulam that serve s as a basis for this problem formulation 6



### . R is ks were identified for terrestrial and aquatic plants, which is consistent with the mode of action of diclosulam a nd its use as an herbicide. However, risk quotients have also exceeded concern levels for terrestrial and aquatic animals as well. These risk concerns are briefly summarized in Table 2

.

Table 2 . Summary of Risk Concerns Previously Identified for Diclosu lam

Birds Mammals Terr. Plants Terr.

Inverts Fish BCF Aquatic Inverts Aquatic

Plants Groundwater

Contamination Persistence Degrad at es of Concern Yes a No Yes No Data Yes b No Yes b Yes Yes Yes NA c

a There are insufficient chronic toxicity data for birds to confirm or rule out potential chronic adverse effects.
b Due to chronic toxicity data gaps, there is uncertainty around the potential for chronic risks to freshwater and marine/estuarine fish and marine/estuarine invertebrates.

c A previous assessment (U SEPA, 2000) noted six major degradates/transformation products having structural similarity to the parent, that were identified in submitted fate studies. The assessment deemed these to “not be of significant concern due to their lower herbicidal effects and low levels” , however noted that the formation of degradate TPSA is expected to also result in formation of 2,6

- dichloroaniline, which is a “ known carcinogen ”

. “ Yes ” = at least one LOC has been exceeded in previous assessments; No = LOCs have not been e xceeded in previous assessments ; NA = RQs have not been calculated previously.



## b. Drinking Water Exposure Assessments

### 7

The previous environmental fate and ecological risk assessment (USEPA 2000) provided acute and chronic estimated drinking water concentrati ons (EDWCs) of 1.55 and 1.36 μg a

. i

. /L, respectively. More recently, a drinking water assessment (DWA) for Registration Review was conducted prior to the finalization of this Problem Formulation in response to specific needs of the Health Effects Division (HED ) 11



### . Maximum EDWCs for diclosulam are shown below.

D rinking W ater S ource (M odel U sed ) U se (rates modeled) M aximum E stimated D rinking W ater C oncentration (EDWC)
A cute ( μg/L ) C hronic ( μg/L ) Cancer ( μg/L )
Surface water (SWCC : MSsoybeanSTD scenario, ground application ) 0.0315 lb a.i./ A /yr 4.44 0.874 0.261

Groundwater ( PRZM

- GW ) 0.0315 lb a.i./ A/ yr (soybeans, NC Norfolk loamy sand soil: cotton) 15.8 11.0 11.0



## c. Clean Water Act Programs

Diclosulam is not identified as a cause of impairment for any water bodies listed as impaired under section 303(d) of the Clean Water Act. No Total Maximum Daily Load (TMDL) criteria have been developed for diclosulam

. At this time a quatic benchmarks ( http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm ) have not been established for diclosulam . Any data submitted or otherwise located as part of the R egistration R eview process may be used to develop aquatic life bench marks if applicable.



# 5. Environmental Fate and Transport

Environmental Fate Characterization

Diclosulam exhibits pH

- dependent aqueous solubility, which ranges from about 100 mg/L at pH 5 to greater than 4000 mg/L at pH 9. Diclosulam’s acid dissociatio n constant ( pK a 

### ) is 4.09 at 20

° C, which suggests that the chemical exists in anionic (negatively charged) form at environmentally relevant pH levels. Diclosulam’s relatively low reported vapor pressure [5 x 10

- 15 

### mm Hg (at 25 °C)] is probably influenced by its pK a 

### ( i.e. , only undissociated molecules can volatilize) ; at environmentally relevant pH values, the compound is not expected to appreciably volatilize . Similarly, diclosulam’s reported octanol/water partition coefficient (K ow 

### ) decreases as pH incre ases from 5 to 9. Diclosulam’s low K ow 

### (maximum of 263 at pH 5) suggests that it is not likely to significantly bioconcentrate in aquatic organisms. General physical/chemical properties are summarized in Table 3

, and submitted environmental fate data fo r diclosulam are summarized in Table 4

. Based on these data, diclosulam is not

11 US EPA, 2015.

### 8

considered to be persistent 12 

### if unextracted residues in the aerobic soil studies ( MRID 43441045) are not considered, but persistent if these residues are included. Aerobic soi l metabolism may be an important mechanism of degradation, but uncertainty about this exists because soil extraction of most samples involved the use of only an acetone:HCl (95:5 v:v) mixture. High levels (from 22 to 51% between 56 and 140 days after trea tment in three soils) of residues were unextracted and uncharacterized, and the possibility that some of these could have consisted of parent diclosulam cannot be ruled out. When unextracted residues are included, diclosulam’s aerobic soil half

- lives incr ease from a range of 29.8

- 57.6 days to a range of 177

- 2520 days. Photolysis ( MRID 44192603) may be an important contributor to diclosulam’s degradation at the soil surface, and anaerobic aquatic metabolism ( MRID 44192604) may be important under anaerobic conditions ( e.g ., in benthic sediments). Hydrolysis of the chemical ( MRID 43441043) is rapid under alkaline conditions ( t 1⁄2 

### = 1.85 days at pH 9), but negligible otherwise. Major degradates include 5

- OH (hydroxyl diclosulam), 8

- Cl ( chlorohydroxy diclosulam ) and ASTP (aminosulfonyltriazolopyrimidine), which reached maxima of 16.6%, 15% and 15.8% of applied radioactivity (AR) respectively, in the aerobic soil study. The 5

- OH degradate was also formed in the anaerobic aquatic study, at a maximum of 34% AR, as was the additional degradate TAAA ( diclosulam triazoloacetic acid ), which was present at a maximum of 34% AR in the aqueous phase. Based on its low organic carbon sorption coefficient (K OC 

### = 33 to 144 ; MRID 43471901 )
, diclosulam is classified as moderate ly mobile to mobile under the FAO system of classification (FAO, 2000) , and particularly in its anionic form the compound is expected to move readily through the environment.

In supplemental terrestrial field dissipation studies 

## ( MRID 446306 0 1) conducted in Georgia and Illinois, diclosulam dissipated with reviewer

- calculated half

- lives (non

- linear regression

- based) of 33.2 and 23.9 days, respectively

. Dissipation at both sites was observed to be biphasic ( therefore linear

- regression

- based half

- lives were substantially longer, at 120 and 70 days, respectively )

. Diclosulam was quantifiable at a maximum depth of 6 to 12 inches during each of the one

- ye ar studies. The study was found not to meet Subdivision N Guidelines because
, although several degradates had been identified in the aerobic soil metabolism study, o nly degradate ASTP was monitored

. ASTP was detected only in the 0

- 6 inch depth interval.

In another supplemental dissipation study ( MRID 44103531), two 150

- day lysimeter tests were performed: one each in North Carolina and Mississippi. Registrant

- calculated mean dissipation half

- lives of diclosulam were 12.5 and 14.8 days for the NC and MS s ite s , respectively. Dissipation at both sites was a lso observed to be biphasic. Degradate ASTP was detected at both sites in the 0

- 15 cm (approximately 0

- 6 inch) depth, at up to 39% of applied radioactivity (MS site, day 7). Degradate 5

- OH was also dete cted in the 0

- 15 cm depth, at maxima of 9% and 4% of applied at the NC and MS sites, respectively. Degradate 8

- Cl was detected in the 0

- 15 cm depth at up to 4

- 5% and 2

- 3% of applied at the NC and MS sites, respectively. Degradate TAAA was detected in the 0

- 15 cm depth at a maximum of 5% of applied radioactivity at both sites. The study was found not to meet Subdivision N Guidelines, in part because complete data were not provided for soil samples below the 15 cm depth , thus data were insufficient to dete rmine the extent of leaching for parent and degradates.

12 Based on the Toxic Release Inventory classification system where half

- lives greater than 60 days in water, soil, and sediment are considered persistent and half

- life greater than 6 months are considered very persistent (USEPA, 2012a)

### 9

Table 3. Chemical Properties and Environmental Fate Parameters of Diclosulam

Parameter Value Source/comment Molecular mass (molecular formula) 406 g/mole (C 14 H 10 Cl 2 FN 2 O 3 S) MRID 45441001

Vapor pressure (20°C) 5 x 10

- 15 mm Hg MRID 43441004 Aqueous solubility (25  C) 117 mg/L at pH 5 124 mg/L at pH7 4290 mg/L at pH 9 USEPA, 2000

Henry’s Law Constant (20°C) Log octanol

- to

- water partition coefficient (log K OW ) 1.42 at pH 5

- 0.047 at pH 7

- 0.448 at pH 9 USEPA, 2000

Hydrolysis half

- lives ( days, 25  C) stable at pH 5 & 7, labile at pH 9 (1.85 d
t 1/2 ) MRID 43441043

Aqueous photolysis half

- life ( days,

25  C) 101 MRID 43441044 ; mean of pyrimidine and aniline ring label results; natural sunlight, Richm ond, CA, Aug

- Sept, 1993

Soil photolysis half

- life (days , 25  C) 48 MRID 44192603; Norfolk loamy sand, mean of pyrimidine and aniline ring label results; natural sunlight

Aerobic soil metabolism half

- li v e s , parent ( days, 25  C) 49.1 (Norfolk sandy loam ), 29 .8 (Commerce silty clay ), 57.6 (Tama silt

loam ) MRID 43441045

Aerobic soil metabolism half

- li v e s , parent+unextracted residues ( days,

25  ) 312 (Norfolk sandy loam ), 2520

(Commerce silty clay ), 177 (Tama silt

loam ) MRID 43441045

Aerobic aquatic metabolism half

li v e s (days , 25  C) 151 MRID 44103530

Anaerobic aquatic metabolism half

li v e s, parent (days , 25  C) 61 (silt loam) MRID 44192604 ; whole

system half

- life, combined labels
S oil

- water sorption coefficients (K d,

mL/g) 0.59, 1.4, 3.79, 0.62 MRID 43471901

Organic

- carbon normalized sorption coefficients (K oc ) ( m L/g OC ) 81, 144, 55, 33 MRID 43471901

Terrestrial field dissipation half

lives (days) 33.2 (Georgia , soybean application pattern ) 23.9 (Illinois , soybean application

pattern ) MRID 446306 0 1

### 10 Parameter Value Source/comment 12.5 (No rth Carolina, soybean application

pattern) 14.8 (Mississippi, soybean application

pattern) MRID 44103531



## a. Transformation Products

Major degradates of diclosulam include 5

- OH, 8

- Cl
, and ASTP, which reached maxima of 16.6%, 15%
, and 15.8 % of applied radioa ctivity (AR) respectively, in the aerobic soil metabolism study. Degradate 5

- OH was also formed in the anaerobic aquatic study, at a maximum of 34% AR, as was TAAA, which was present at a maximum of 34% AR in the aqueous phase. The additional degradate T PSA ( triazolopyrimidinesulfonic acid ) was detected at 0.5 and 8.8% in the aquatic and soil photolysis studies, respectively

. Although not reported as detected in any fate studies, 2,6

- dichloroaniline is also expected to be form ed as a consequence of the c onversion of diclosulam to TPSA. A position al isomer of 2,6

- dichloroaniline is 3,5

- dichloroaniline, which is an identified degradate of other pesticides
, and as such has been named a residue of concern.

### 11

Table 4

. Diclosulam and Its Major Environmental Degradates

Code Name/ Synonym Chemical Name Chemical Structure Study Type Ref. (MRID) Maximum

%AR (day) A 

### Final %AR

(study length)

PARENT Diclosulam

SMILES: ClC1=C(C(=CC=C1)Cl)N [S](=O)(=O)C3=N[N]2C( =NC(=CC2=N3)F)OCC N

- (2,6

- dichlorophenyl)

- 5

- ethoxy

- 7

- fl uoro[l,2,4]triazolo

- [l,5

- c] pyrimidine

sulfonamide

MAJOR TRANSFORMATION PRODUCTS 5

- OH

hydroxy diclosulam

SMILES: ClC1=C(C(=CC=C1)Cl)N ([S](=O)(=O)C3=N[N]2C( =NC(=CC2=N3)F)OCC)[ H] N

- (2,6

- dichlorophenyl)

- 5

- hydroxy

- 7

- fluoro

- [l,2,4]triazolo[l,5

- c]

- pyr imidine

- 2

- sulfonamide Hydrolysis 43441043 59.8 (4), pH 9 only 59.8 (4) Aqueous photolysis 43441044

-- -- Soil photolysis 44192603 1.6 (26) 1.5 (30)

Aerobic soil 43441045

44045201 16.6 (140) 13.2 (182) Aerobic aquatic 44103530 2.9 (32) 2.9 (32)

Anaerobic aquatic 44192604 3 8.7 water ( 365 ) 4

. 1 sediment ( 365 ) 38.7 (365)

TFD A,B 446306 0 1

44103531 --

9 (8) --

n.d. (148) 8

- Cl

chloro hydroxy diclosulam

SMILES: ClC1=C(C(=CC=C1)Cl)N ([S](=O)(=O)C3=N[N]2C( =NC(=C(C2=N3)Cl)F)O[ H])[H] N

- (2,6

- d ichlorophenyl)

- 8

- chloro

- 7

- fluoro

5(6H)

- oxo[l,2,4]triazolo[l,5

- c]

- pyrimidine

- 2

- sulfonamide Hydrolysis 43441043

-- -- Aqueous photolysis 43441044

-- -- Soil photolysis 44192603

-- --

Aerobic soil 43441045

44045201 15 (1 8 2) 15 (182)

Aerobic aquatic 44103530

-- -- Anaerobic aquatic 44192604

-- --

### 12

Code Name/ Synonym Chemical Name Chemical Structure Study Type Ref. (MRID) Maximum

%AR (day) A 

### Final %AR

(study length)

TFD A,B 446306 0 1

44103531 --

5 (42) --

n.d. (148) TAAA

diclosulam triazoloacetic acid or XDE

- 564 triazoloacetic acid

SMILES: ClC1=C(C(=CC=C1)Cl)N ([S](=O)(=O)C2=N[N](C( =N2)CC(=O)O[H])[H])[ H ] N

- (2,6

- dichloropheny1)

- 3

- [1,2,4]triazoloacetic acid

- 5

- sulfonamide Hydrolysis 43441043

-- -- Aqueous photolysis 43441044 -- --
Soil photolysis 44192603

-- --
Aerobic soil 43441045

44045201 -- -- Aerobic aquatic 44103530 2.1 (32) 2.1 (32)

Anaerobic aquatic 44192604 34 .2 water ( 365 ) 4.3 sediment ( 365 ) 34.2 (365)

TFD A,B 446306 0 1

44103531 --

5 (61) --

n.d. (148) ASTP

a minosulfonyltriaozlopyri midine

SMILES: N([S](=O)(=O)C2=N[N]1 C(=NC(=CC1=N2)F)OCC )([H])[H] 5

- ethoxy

- 7

- fluoro[l,2, 4]triazolo[l,5

- c]pyrimidine

- 2

- sulfonamide Hydrolysis 43441043

-- -- Aqueous photolysis 43441044

-- -- Soil photolysis 44192603 0.5 (26) 0.0 (30)

Aerobic soil 43441045

44045201 15.8 ( 56 ) 8.1 (182) Aerobic aquatic 44103530

-- -- Anaero bic aquatic 44192604

-- --

TFD A,B 446306 0 1

44103531 10 (1 19 )

39 (7) n.d. (36 4 )

4 (150) TPSA

triazolopyrimidinesulfonic acid

SMILES: [S](=O)(=O)(C2=N[N]1C( =NC(=CC1=N2)F)OCC)O [H] 5

- ethoxy

- 7

- fluoro[l,2,4]triazolo[l,5

- c]pyrimidine

- 2

- sulfon ic acid Hyd rolysis 43441043

-- -- Aqueous photolysis 43441044 8.8 (30) 8.8 (30) Soil photolysis 44192603 0.5 (30) 0.5 (30)

Aerobic soil 43441045

44045201 -- -- Aerobic aquatic 44103530

-- -- Anaerobic aquatic 44192604

-- --

### 13

Code Name/ Synonym Chemical Name Chemical Structure Study Type Ref. (MRID) Maximum

%AR (day) A 

### Final %AR

(study length)

TFD A,B 446306 0 1

441 03531 --

7 (14) --

n.d. (148) CO 2 Carbon dioxide Hydrolysis 43441043

-- -- Aqueous photolysis 43441044

-- -- Soil photolysis 44192603 7 (30) 7 (30)

Aerobic soil 43441045

44045201 45.4 (365) 45.4 (365) Aerobic aquatic 44103530 0.9 (32) 0. 9 (32) Anaerobic aquatic 44192604

-- --

TFD A,B 446306 0 1

44103531 -- --

A n.d. means “not detected”.

B Terrestrial field study percentages represent the ratio of degradate concentration to the maximum parent concentration, both in the top layer of soil.

### 14



# 6. Receptors

Tables 5 and 6 provide a summary of the acute and chronic toxicity data for the aquatic and terrestrial organisms that serve as surrogates for broader taxonomic groups used to assess the potential acute and chronic ecological effects of diclosulam.

Diclosulam is particularly toxic to aquatic and terrestrial plants , which is expected for an herbicide. Available data for mallard ducks suggest that diclosulam causes eggshell thinning on a chronic exposure basis.



## a. Effects to Aquatic Organi sms

Based on the available ecotoxicity data
, diclosulam is slightly toxic to freshwater invertebrates and practically non

- toxic to freshwater fish (and to aquatic

- phase amphibians for which freshwater fish serve as surrogates) , estuarine/marine fish and e stuarine/marine invertebrates on an acute exposure basis ( Table 5 ). The only chronic toxicity data, i.e ., no observed adverse effect concentrations (NOAEC), available for diclosulam for aquatic animals are for freshwater invertebrates ( Daphnia magna ) and resulted in a reduction in the number of young per adult).

Although acute toxicity tests with many of the aquatic animals resulted in non

- definitive endpoints, i.e ., lethal concentrations for 50% of the organism tested (LC 50 

### ) and effect concentration for 50% of the organism tested (EC 50 

### ) values greater than the highest concentration tested vascular aquatic plants have an EC 50 

### value (EC 50 

### = 0.001 m g/L ) which is orders of magnitude more sensitive than the aquatic animals tested ( Table 5 )

. H owever, the most sensitive of the nonvascular aquatic plants tested failed to establish a definitive endpoint ( Skeletenoma
costatum EC 50 

### >113 mg a

. i

. /L) and was several orders of magnitude less sensitive than the vascular aquatic plant Lemna gibba

.

D ata with which to eva luate the toxicity of degradates relative to the parent compound are not available for aquatic animals. However, a quatic plant toxicity studies for three diclosulam degradates ( i.e. , 5

- OH, 8

- Cl and ASTP) indicate that the parent diclosulam is more toxic t o vascular aquatic plants than are the three degradates ( Table 6 ). However, while toxicity tests of nonvascular aquatic plants with parent diclosulam resulted in a non

- definitive endpoint ( i.e
, EC 50 

### >113 mg/L ), toxicity tests with the three degradates resu lted in definitive EC 50 

### values ranging from 19 to 39.6 mg a

. i

. /L).

### 15

Table 5 . Summary of the M ost S ensitive E ndpoints from A quatic T oxicity S tudies for Diclosulam

Taxonomic Group Study Type Surrogate Species Toxicity Value (all units in terms of measured active ingredient ) Acute Toxicity

Classification MRID, Classification

Freshwater fish 1 Acute Rainbow Trout ( Oncorhynchus mykiss ) LC 50 > 110 mg

a.i. /L Practically non

toxic 43441013 , Acceptable

Freshwater invertebrates Acute Water Flea ( Daphnia magna ) EC 50 = 72 mg

a.i. /L Slightly toxic 43441014 , Acceptable

Chronic Water Flea

( Daphnia magna ) NOA EC =

2.05 mg a.i. /L LOA EC = 3.16 mg a.i. /L Endpoint: reproduction N/A 43441018 , Acceptable

Estuarine/marine fish Acute Inland Silverside ( Menidia beryllina ) L C 50 >120 mg

a.i./L Practically non

toxic 43441015 , Acceptable

Estuarine/marine invertebrates Acute Eastern Oyster ( Crassostrea virginica ) EC 50 >117 mg

a.i /L Practically

Non

- Toxic 43441016, Acceptable

Aquatic plants and algae Vascular Duckweed ( Lemna gi bba ) EC 50 = 0.00 11

m g a.i. /L ; NOAEC = 0. 000 6 m g a.i. /L -- 4441 3538 , Acceptable

Non

vascular Marine diatom

( Skeletenoma
costatum ) EC 50 >113 ;

NOAEC = 113 mg a.i. /L -- 44103539, Acceptable

1 Freshwater fish may be surrogates for aquatic

- phase amphibians.



### Table 6 . Summary of the M ost S ensitive E ndpoints from A quatic Plant T oxicity S tudies for 5

- OH , 8

- Cl and TAAA [Degradate s of Diclosulam ]

Taxonomic Group Study Type Surrogate Species Toxicity Value (all units in terms of measured active ingredient) MRID , Classification

5

- OH

Aquatic plants and algae Vascular Duckweed ( Lemna gibba ) EC 50 =49.5 mg a.i. /L NOAEC=12 mg a.i. /L 44587808, Acceptable

### 16

Taxonomic Group Study Type Surrogate Species Toxicity Value (all units in terms of measured active ingredient) MRID , Classification

Non

vascular Green Algae

( Pseudokirchneria subcapitata ) EC 50 = 39.6 mg a.i. /L NOAEC= 23.7 mg a.i. /L 44587809, Acc eptable

8

- Cl

Aquatic plants and algae Non

Vascular Green Algae

( Pseudokirchneria subcapitata ) EC 50 =19 mg a.i./L NOAEC= ND 44103543, Acceptable

TAAA

Aquatic plants and algae Non

Vascular Green Algae

( Pseudokirchneria subcapitata ) EC 50 =36 mg a.i./L NOAE C=10 mg a.i./L 44103544, Acceptable



## b. Effects to Terrestrial Organisms

Available toxicity data indicate that diclosulam is practically nontoxic to birds (and to terrestrial

phase amphibians and reptiles for which birds serve as surrogates) and mammals on a n acute oral exposure basis and is slightly toxic to birds on a subacute dietary exposure basis ( Table 7 )

. Chronic exposure resulted in a decrease in eggshell thickness in birds at each of the dietary concentrations tested and therefore resulted in a non

- definitive endpoint, i.e ., NOAEC<50 mg/kg diet, in mallard ducks (

Anas platyr

h ynchus ) whi le higher dietary levels resulted in decreased embryo viability, hatchling survival, egg production, and female (parental) body weight. Chronic exposure of rabbits ( Or

yctolagus cuniculus ) to diclosulam resulted in an incre ased number of abortions (NOAEL= 65 mg a.i. /kg bw/day)

. Diclosulam is practically non

- toxic to honey bees ( Apis mellifera ) on an acute contact exposure basis . There are no data on oral exposure to adul t or larval honey bees, or to adult or larval bees on a chronic basis. E xposure of earthworms ( Eisenia foetida ) to the compound resulted in a non

definitive endpoint (LD 50 

### >991 mg a

. i

. /kg) ( Table 7 ).

Toxicity testing with terrestrial plants resulted in t oxicity estimates for monocotyledenous and dicotyledenous plants of 0.00024 lb a.i./acre 0.00006 lb a.i./acre (cotton) to 0.01 lb a.i./acre (soybeans).

Three diclosulam degradates (5

- OH, 8

- Cl and ASTP) for which toxicity data are available, have been show n to be much less toxic to terrestrial plants relative to the parent compound. In the study (MRID 44656201)
, eleven species of plants 13 

### were exposed to the 5

- OH, 8

- CL and ASTP degradates at concentrations much higher than would b e expected to result during the course of

13 Beet, cabbage, cucumber, radish, soybean, sunflower, tomato, corn, onion, ryegrass and wheat.

### 17

normal use of diclosulam (degradate application rate: 0.0468 lb degradate/acre). Toxicity data for the most sensitive terrestrial organisms are presented in Tabl e 7 below.

Table 7. Summary of the M ost S ensitive E ndpoints from T errestrial T oxicity S tudies for Diclosulam Taxonomic Group Study

Type Surrogate

Species Toxicity Value

(all units in terms of measured active ingredient) Acute

Toxicity Classification MRID, Classification

Birds 1 Acute Bobwhite quail ( Colinus virginianus ) LD 50 >2250 mg

a.i. /kg

- bw Practically

non

- toxic 43441008 , Acceptable

Sub

- acute dietary Mallard Duck

( Anas Platyrhynchos ) LC 50 >4496 mg

a.i./kg diet Slightly Toxic 4344101 1, Acceptable

Northern Bobwhite ( Colinus virginianus ) LC 50 >4496 mg

a.i./kg diet Slightly T oxic 43441010 , Acceptable

Chronic Northern

Bobwhite ( Colinus virginianus ) NOAEC = 1000 mg

a.i./kg diet LOAEC = 2000 mg a.i./kg diet N/A 44103536 , Acceptable

Mallard Duck ( Anas Platyrhynchos ) NOAEC <50

mg/kg

- diet N/A 44192605 , Supplemental

Mammals Ac ute Oral Laboratory rat ( Rattus norvegicus ) LD 50 >5,000 mg

a.i. /kg

- bw Practically

non

- toxic 43441021, Acceptable

Chronic New Zealand

White Rabbit ( Oryctolagus cuniculus ) NOAEL = 65 mg

a.i. /kg/day LOAEL = 10 mg a.i. /kg/day Endpoint: increased number of a bortions N/A 44103524 , Acceptable

Terrestrial Invertebrates Acute

contact Honey bee

( Apis mellifera L. ) LD 50 >25 μg

a.i. /bee Practically

non

- toxic 43441019 , Acceptable

Acute
contact Earthworm

( Eisenia foetida ) LD 50 >991 mg a.i. /kg

-- 43441020 , Accepta ble

Terrestrial plants Seedling

Emergence Dicot

- Carrot NOAEC = 0.0005 lb s a.i./A EC 25 = 0.0026 lb s a.i./A Endpoint: Biomass -- 44103537 , Acceptable

Monocot

- Onion NOAEC = 0.0001

lb s a.i./A EC 25 = 0.00024 lb s a.i./A Endpoint: Biomass -- 44103537 , Acce ptable

### 18

Taxonomic Group Study

Type Surrogate

Species Toxicity Value

(all units in terms of measured active ingredient) Acute

Toxicity Classification MRID, Classification

Vegetative Vigor Dicot

- Cotton NOAEC=0.00002 lb s a.i./A EC 25 =0.00006 lb s a.i./A Endpoint: Biomass -- 44103537 , Acceptable

Monocot

- Onion NOAEC=0.0002 lb s

a.i./A EC 25 =0.0003 lb s a.i./A Endpoint: Biomass -- 44103537 , Acceptable

1 Birds represent s urrogates for terrestrial

- phase amphibians and reptiles.



## c. Ecological Incidents

The ecological incident information system (EIIS) is an OPP database that houses ecological incidents that have been reported to EPA

. The EIIS includes the date and location of an incident, type and magnitude of effects observed in various species, use(s) of pesticides known or suspected of contributing to the incident, and results of any chemical residue analysis or other analyses conducted during incident investigation ; howeve r, depending of the incident, not all of these data may be available . EIIS incidents are categorized according to the certainty that the incident resulted from pesticide exposure. The Avian Monitoring System (AIMS) is a database administered by the Ameri can Bird Conservancy that contains publicly available data on reported avian incidents involving pesticides. Many of the incidents listed in this database are also in the EIIS

.

Based on a review of the EIIS database in February 2015, there are 37 incid ents , all involving terrestrial plants across four states ( T exas, G e o rgia, Oklahoma and New Mexico ); these incidents

were a ssociated with diclosulam use on peanuts primarily during the spring of 2000 . Most of these were listed with “ probable” certainty (se e Appendix D for a recent printout of diclosulam incidents).

As of 5 February, 2015
, AIMS identified no avian incidents involving diclosulam

.



# 7. Exposure Pathways of Concern

The environmental fate properties and use patterns of diclosulam indicate that direct spray, spray drift, leaching to ground water, atmospheric deposition, and runoff represent potential transport mechanisms to aquatic and terrestrial organisms. Drinking water and inhalation exposure pathways were screened using the SIP (Screening I mbibition Program) and STIR (Screening Tool for Inhalation Risk) screening methods . While inhalation exposure was found to be an exposure pathway of low concern (no LOC exceedances are expected) for both birds and mammals, drinking water exposure was found to be an exposure pathway of concern (LOC exceedances are expected) . SIP and STIR are described in detail at: http://www.epa.gov/oppefed1/models/terrestrial/index.htm

.

### 19



# 8. Analysis Pla n

a. Stressors of Concern

i. Ecological Risk Assessment

The stressor of ecologic al concern for terrestrial and aquatic organisms is the parent chemical diclosula m

. Degradates are generally expected to be more mobile than the parent compound, and limited data ( MRID 43471901) tend to confirm that this is the case, at least for the 5

- OH degradate

. Ecotoxicity data on aquatic and terrestrial plants are available for the major degradates of diclosulam. ECOSAR (v 1.11) results indicate that the 5

- OH and 8

- Cl degrada tes may exhibit toxicity to daphnids that is similar to that of parent diclosulam. For human health concerns a 1999 meeting of the Health Effects Division’s (HED) Metabolism Assessment Review Committee (MARC) concluded t hat only the parent compound needed to be included in the tolerance expression. However, h 

### igh levels (up to 51%) of residues in the aerobic soil metabolism study were unextracted and uncharacterized, and the possibility that some of these could have consisted of parent diclosulam cannot be ruled out. Therefore, i 

### n accordance with EFED’s interim guidance for addressing unextracted residues (USEPA, 2013) EFED plans on includ ing unextracted residues together with the parent compound in the ecological aquatic exposure modeling unless data is p rovided which identifies the unextracted residues or demonstrates that adequate measures were used to try to extract the residues.

ii. Drinking Water

The drinking water assessment ( DWA ) for Registration Review was conducted prior to the finalization of this Problem Formulation in response to specific needs of HED 14



### . The Pesticide Root Zone Model (PRZM) and the Exposure Analysis Modeling System ( EXAMS ) , as implemented in EFED’s Surface Water Concentration Calculator (SWCC, version 1.106; 5/22/2014), were used to generate surface water estimated drinking water concentrations ( EDWCs ) for use in the human health dietary risk assessment, while the PRZM

- Groundwater (PRZM

- GW) and Screening Concentration in Ground Water (SCI

- GROW , version 2.3; 10/23/2010 ) models wer e used to generate groundwater EDWCs. The maximum acute, chronic and cancer surface water EDWCs were associated with the soybean use

. T he maximum EDWC values recommended for use in the human health dietary risk assessment were 15.8 μg/L for acute EDWC an d 11.0 μ g/L for chronic and cancer EDWCs

. These values were generated for groundwater sources of drinking water using PRZM

- GW, and were significantly higher than the values determined for surface water sources of drinking water. The EDWCs included unextr acted residues and identified parent diclosulam. High levels (up to 51%) of residues in the aerobic soil metabolism study were unextracted and uncharacterized, and the possibility that some of these could have consisted of parent d iclosulam cannot be rule d out. In modeling diclosulam in drinking water, the mean soil sorption coefficient (K OC 

### = 78 mL/g oc 

### ) for parent diclosulam was employ ed as an input parameter.

14 US EPA, 2015

### 20



## b. Measures of Exposure

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

. Screening level calculations have sugge sted that the drinking water exposure pathway may be significant. Th i s exposure pathway may be further considered at the time o f the risk assessment ( Appendix C ).

i. Available Monitoring Data

The Agency is not aware of monitoring conducted by federal and state agencies for diclosulam. If information on monitoring becomes available, it will be considered in the assessment to the extent that data on diclosulam are available.



## c. Measures of Effect

Toxicity data presented in Section 3 of this problem formulation will be used to calculate risk quotients (RQs) . Any additional information submitted by the registrant or found in the open literature prior to conduct of the risk assessment will also be considered. The open lit erature studies are identified using EPA’s ECOTOXicology database ( ECOTOX) ( USEPA, 2007 c ), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife. The evaluation of both sources of d ata can also provide insight into the direct and indirect effects of pesticides on biotic communities from loss of species that are sensitive to the chemical s and from changes in structure and functional characteristic s of the affected communities.



## 9. Endang ered Species Assessments

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), the Agency will evaluate risks to listed species from registered uses of pesticides in R egistration R eview

. The process for evaluating potential risks to listed species is further described at http://www.epa.gov/oppfead1/endanger/litstatus/riskasses.htm

.



## 10. Endocrine Disruptor Screening Program

Diclosulam was not included i n the first group of 67 chemicals issued an order to conduct Tier 1 EDSP testing. For additional information the EDSP program, visit http://www.epa.gov/endo/

.

### 21



## 11. Preliminary Identification of Data Gaps

a. Environment

al Fate

Tables 8 and 9 identify environmental fate studies by MRID that offer data for each guideline requirement, as well as study classifications and whether or not further data are needed in order to support risk assessment. Rationale s for the additio nal data requested are presented below the tables.

Table 8 . Submitted Environmental Fate Data for Diclosulam

OCSPP Guideline Data

Requirement Submitted

Studies (MRID) Study

Classification Data

Gap? Are data needed to conduct risk assessment? Justification and

Assumptions EPA will Make in Absence of Data 835.2120 Hydrolysis 43441043 Acceptable No No

835.2240 Aqueous

photolysis 43441044 Acceptable No No

835.2410 Soil photolysis 44192603 Supplemental Yes No

835.4100 Aerobic soil

metabolism 43441045 Su pplemental Yes Yes Data available on three soils. Data are needed on at least one additional soil, and should include additional characterization of unextracted residues.

835.4200 Anaerobic soil

metabolism NA NA No No

835.4300 Aerobic aquatic

metabolis m 44103530 Supplemental Yes No If data are only available on one sediment, the estimated half

- life will be multiplied by three.

835.4400 Anaerobic

aquatic metabolism 44192604 Acceptable No No

835.1230 835.1240 Adsorption/

desorption and leaching 4347190 1 Acceptable No No

835.6100 Terrestrial field

dissipation 44103531 Supplemental Yes No

446306 0 1 Supplemental Yes No

850.7100 Environmental

Chemistry and Independent Laboratory Validation Method: Water 44587803

44587804 -- No No Existing methods u sed in TFD study 44630601 have limit of quantitation (LOQ) for the parent below 0.6 μg/L ( i.e ., the NOAEC for most sensitive species) that may be used in monitoring

. 165

- 4 (850.1730) Fish

bioconcentration NA NA No No Not required because K OW is < 1000 ( 40 CFR Part 158.630)

### 22

Rationale for Requesting Fate Studies

Aerobic Soil Metabolism (OPPTS Guideline 835.4100), t est substance diclosulam. Data are routinely required for four soils. Data on diclosulam are currently available for only three soils, and the soil extraction methods, which employed only acetone:HCl, may have been inadequate. Unextracted residues constituted 36.3

- 51.2% of applied radioactivity. This creates significant uncertainty for the risk assessment. Due to the uncertainty in the id entity of these residues, in the absence of additional data, it will be assumed that the unidentified residues are residues of concern in estimating half

- lives. It will be assumed that unextracted residues have similar toxicity to the parent compound. Ad ditional studies that make an effort to ensure that all residues that can be extracted from soil and sediment are extracted 15 

### , and that those residues are identified, could significantly reduce the uncertainty resulting from having significant amounts of un extracted and unidentified residues in metabolism studies.



## b. Effects

Tables 9

- 1 1 identify ecological effects studies by MRID that provide data for each guideline requirement, as well as study classifications and whether or not further data are needed in or der to support risk assessment. Rationale s for the additional data requested are presented below the tables.

Table 9

. Submitted A quatic E cological E ffects D ata for Diclosulam

OCSPP Guideline Data

Requirement Submitted

Studies (MRID) Study

Classificatio n Are data

needed to conduct risk assessment? Justification and Assumptions

EPA will Make in Absence of

Data

850.1010 Freshwater

invertebrate acute toxicity 43441014 Acceptable No

850.1025 850.1035 850.1045 850.1055 Saltwater

invertebrate
acute tox icity 43441016 Acceptable No

850.1075 Freshwater

fish acute toxicity 43441013 Acceptable No

43441012 Acceptable

850.1075 Saltwater fish

acute toxicity 43441015 Acceptable No

850.1300 Freshwater

invertebrate life cycle 43441018 Acceptable No

15 A reasonable effort to ex tract all residues would include employing a variety of extraction solvents and testing extraction efficiencies for known analytes. Use of acids and bases if they do not alter the chemical of interest may also be used.

### 23

OCSPP Guideline Data

Requirement Submitted

Studies (MRID) Study

Classificatio n Are data

needed to conduct risk assessment? Justification and Assumptions

EPA will Make in Absence of

Data

850.1350 Saltwater

invertebrates life cycle No Data

-- Yes Presumption of risk for these taxa.

850.1400 Freshwater

fish early

- life stage No Data

-- Yes Presumption of risk for these taxa.

850.1400 Saltwater fish

early

- life stage No Data

-- Yes Presumption of risk for these taxa.

850.1500 Fish life cycle No Data

-- No

850.4400 Aquatic plant

Toxicity Test using Lemna spp. 44103538 Acceptable No

850.4500 Algal toxicity 44103539 Acceptable No

44103540 Acceptable No

850.4550 Cyanoba cteria 44103541 Acceptable No



### Rationale for Requesting Aquatic Organism Studies

No chronic toxicity data for freshwater fish have been submitted. Because diclosulam (a) is expected to be transported to water from the intended use site and (b) is persi stent in water, a study is recommended on the Early Life Stage test ( Guideline 850.1400) with freshwater fish species.

No chronic toxicity data for estuarine/marine fish have been submitted. Because diclosulam 

## (a) is expected to be transported to water f rom the intended use site and 

## (b) is persistent in water, a study is recommended on the Early Life Stage study ( Guideline 850.1400 ) with an estuarine/marine fish species.

No chronic toxicity data for estuarine /m arine invertebrates have been submitted

. Bec ause diclosulam (a) is expected to be transported to water from the intended use site and (b) is persistent in water, an aquatic invertebrate life

- cycle study ( Gu ideline 850.1350) using estuarine/ marine invertebrate species, preferably a mysid ( Americamysi s bahia ) is recommended

.

### 24

Table 10

. Submitted Aquatic Ecological Effects Data for Diclosulam Degradates (5

- OH, 8

- Cl, TAAA )

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study

Classification Are data

needed to conduct risk assessment? Jus tification and

Assumptions EPA will Make in Absence of Data
5

- OH Degradate

850.45 00 5

- OH: Algal Toxicity with

Green Algae ( Selenastrum capricornutum ) 44103542 Acceptable No

850.4400 5

- OH: Aquatic Plant

Toxicity with Duckweed ( Lemna gibba ) 44587808 Ac ceptable No

850.45 00 5

- OH: Algal Toxicity with

Green Algae ( Pseudo kirchneriella subcapitata formerly Selenastrum capricornutum ) 44587809 Acceptable No

850.455 0 5

- OH: Algal Toxicity with

Blue

- Green Algae ( Anabaena flos

- aquae ) 44587810 Acceptable No

8 50.4 5 00 5

- OH: A lgal Toxicity with

Marine Diatom ( Skeletonema costatum ) 44587806 Acceptable No

850.45 00 5

- OH: Algal Toxicity with

Freshwater Diatom ( Navicula pelliculosa ) 44587807 Acceptable No

8

- Cl Degradate

850.4400 8

- Cl: Algal Toxicity with

Green A lgae ( Selenastrum capricornutum ) 44103543 Acceptable No

TAAA Degradate

850.4400 TAAA: Algal Toxicity

with Green Algae ( Selenastrum capricornutum ) 44103544 Acceptable No

### 25

Table 11

. Submitted Terrestrial E cological E ffects D ata for Diclosulam

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study

Classifications Are data

needed to conduct risk assessment? Current

Additional Data Need

850.2100 Avian oral toxicity 43441008 Acceptable No

850.2200 Avian dietary toxicity 43441010 Acceptable No

-- 43441011 Acceptable

850.2300 Avian reproduction 44103536 Acceptable Yes Presumption of risk for these taxa. 44192605 Supplemental

Non

guideline Avian inhalation N/A N/A

850.3020 Honey bee acute contact

toxicity 43441019 Acceptable N o

--

Non

G uideline Honey bee adult acute oral

toxicity a N/A N/A Yes An acute oral toxicity study with the adult honey bee is needed.

Non

G uideline Honey bee larvae acute

oral toxicity b N/A

N/A Yes An acute oral toxicity study with the larval honey bee is neede d.

Non

G uideline e H oney bee adult chronic

oral toxicity c N/A

N/A Yes A chronic 10 day oral toxicity study with the adult honey bee is needed.

Non

G uideline e H oney bee larvae chronic

oral toxicity c N/A N/A Yes A repeat dose larval toxicity study with the honey be e is needed.

Non

G uideline e Honey bee semi

- field

(tunnel or colony

- feeding)
test

– TEP d N /A N/A Yes May be triggered based on results of lower tier honey bee toxicity studies.

Non

G uideline e Field trial of residues in

pollen and nectar

– TEP N /A N/A Yes May be triggered based on results of lower tier honey bee toxicity studies.

### 26

OCSPP Guideline Data Requirement Submitted Studies (MRID) Study

Classifications Are data

needed to conduct risk assessment? Current

Additional Data Need

850.3030 Honey bee toxicity of

residues on foliage

— TEP N /A N/A No Not triggered at this time based on ecotoxicity data, predicted EECs, fate properties, and use pattern criteria.

850.3040 e Field testing for

pollinators

– TEP N /A N/A Yes May be triggered based on results of lower tier honey bee toxicity studies.

850.4100 S eedling E mergence and

Seedling Growth 44103537 Acceptable No

--

850.4150 V egetative V igor 44103537 Acceptable No

( a ) Honey bee acute oral toxicity test protocol available through OECD TG 213. 16
(b ) Honey bee acute larval toxicity test protocol available through OECD TG 237. 17 In some cases, information pertaining to acute toxicity to honey bee larvae may be obtained with the chronic honey bee larval test thereby negating the need for separate acute and chr onic larval toxicity tests. (c ) Draft test protocols are currently being finalized through the OECD. ( d ) Semi

- field tunnel study protocol available through OECD Guidance 75. 18
( e ) Study protocol should be submitted for review prior to conduct of the study.


### Rationale for Requesting Terrestrial Organism Studies

The avian reproduction study with the Northern bobwhite ( Colinus virginianus ) indicates that exposure to diclosulam was associated with a decrease in egg shell thickness (NOAEC = 

### 1000 ppm, LOAEC = 

### 200 0 ppm). The reproduction study with the mallard duck (MRID 44192605) shows that diclosulam was also associated with a 

### decrease in eggshell thickness below the lowest concentration tested of 50 ppm (both LOAEC and NOAEC < 

### 50 ppm). Since the mallard duck test did not establish a NOAEC or a LOAEC, the study is classified as supplemental and the guideline requirements for waterfowl are not satisfied. Another reproduction study with the mallard duck is needed to determine a definitive NOAEC (guideline 850.2300).

For insect pollinator testing, EPA has recently implemented new guidance for insect pollinator risk assessment ( USEPA, PMRA, and CDPR, 2014)

. Recommended s tudies relevant to diclosulam include the acute and chronic oral toxicity studies with adult bees an d acute and chronic toxicity studies with larval bees as well as higher tiered field studies

.

16 OECD. 1998 a . OECD Guidelines for t he Testing of Chemicals. Honeybees, Acute Oral Toxicity Test. 213. http://lysander.sourceoecd.org/vl=5988235/cl=1 2/nw=1/rpsv/cgi

- bin/fulltextew.pl?prpsv=/ij/oecdjournals/1607310x/v1n2/s14/p1.idx

17 OECD. 201 3 . OECD Guidelines for Testing Chemicals. Honey bee ( Apis mellifera ) larval toxicity test, single exposure. http://www.oecd

ilibrary.org/environment/test

- no

- 237

- honey

- bee

- apis

- mellifera

- larval

- toxicity

- test

- single

- exposure_9789264203723

- en 18 OECD. 2007. Series on Test ing and Assessment Number 75. Guidance document on the honey bee ( Apis mellifera L.) brood test under semi

field conditions. Environmental Directorate Joint Meeting of the Chemicals Committee and the Working Party on Chemicals, Pes ticides and Biotechnolo gy. ENV/JM/MONO(2007)22. 31

- Aug

- 2007. http://www.oecd.org/officialdocuments/publicdisplaydocumentpdf/?cote=env/jm/mono(2007)22&doclangua ge=en

### 27



# 12. References

FAO. 2000. Appendix 2. Parameters of pesticides that influence processes in the soil. In FAO Information Division Editorial Group (Ed.), Pesticide Disposal Series 8. Assessing Soil Contamination. A Reference Manual . Rome: Food & Agriculture Organization of the United Nations (FAO). Available at http://www.fao.org/DOCREP/003/X2570E/X2 570E06.htm (Accessed March 24 , 20 15 ).

US EPA

. 2000. Environmental Fate and Ecological Risk Assessment for the Registration of Diclosulam. United States Environmental Protection Agency (US EPA). Environmental Fate and Effects Division. Office of Pestic ide Programs. 2/29/2000.

US EPA

. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs. United States Environmental Protection Agency (USEPA). Environmental Fate and Effects Division. Office of Pesticide Programs. A vailable at http://www.epa.gov/espp/consultation/ecorisk

- overview.pd f

US EPA

. 2014. BEAD Chemical Profile (BCP) for Registration Review: Diclosulam (129122).

. United States Environmental Protection Agency (USEPA). Biological and Economic Analysis Divisio n. Office of Pesticide Programs. 12/12/2014.

USEPA, PMRA, and CDPR, 2014. Guidance for Assessing Pesticide Risks to Bees. Office of Pesticide Programs, USEPA, Washington D.C. Health Canada Pest Management Regulatory Agency, Ottawa, ON, Canada. California Department of Pesticide Regulation, Sacramento, CA. June 23, 2014.

US EPA

. 2015. Diclosulam Drinking W ater A ssessment for Registration Review. United States Environmental Protection Agency (US EPA). Environmental Fate and Effects Division. Office of Pe sticide Programs

. 3/19/2015.

### 28 

## Appendices

A 1 . OPPIN Bibliography for Ecological Effects Data
A2. OPPIN Bibliography for Environmental Fate Data
B. STIR Model Output

C. SIP Model Output

D. Table of Incidence Data from EIIS for Diclosulam

### 29 Appendix A 1

. OPPIN Bibliography for Ecological Effects Data

PC Code 129122 Diclosulam Eco Effects Bibliography Folder

- F002267 Revised 29 July 2014

71

- 1 Avian Single Dose Oral Toxicity

MRID PDF # Citation Reference

43441008 2050446

2050445

-
memo Ca mpbell, S.; Beavers, J. (1994) XDE

- 564 Herbicide: An Acute Oral Toxicity Study with the Northern Bobwhite: Amended

Report: Lab Project Number: ES/DR/0313/5691/4: 103/370. Unpublished study prepared by Wildlife International Ltd. 26
p.

71

- 2 Avian Di etary Toxicity

MRID PDF # Citation Reference

43441009 Support data Rick, D.; Stahl, D. (1992) XDE

- 564 Herbicide: Stability in Game Bird Starter Ration: Lab Project Number: DECO/ES/2468: ES/DR/ 0313/5691/1. Unpublished study prepared by The Dow Chem ical Co. 16 p.

43441010 2050521

2050445

-
memo Campbell, S.; Beavers, J. (1994) XDE

- 564 Herbicide: A Dietary LC50 Study with the Northern Bobwhite: Amended Report:

Lab Project Number: ES/ DR/0313/5691/2: 103/368. Unpublished study prepared by Wildlife Int ernational Ltd. 25 p.

43441011 2050522

2050445

-
memo Campbell, S.; Beavers, J. (1994) XDE

- 564 Herbicide: A Dietary LC50 Study with the Mallard: Amended Report: Lab Project

Number: ES/DR/0313/5691/3: 103/369. Unpublished study prepared by Wildlife Interna tional Ltd. 26 p.

71

- 4 Avian Reproduction

MRID PDF # Citation Reference

44103536 2050447 Beavers, J.; Chafey, K.; Mitchell, L.; et al. (1995) XDE

- 564 Herbicide: A Reproduction Study with the Northern Bobwhite (Colinus virginianus): (Final R eport): Lab Project Number: 103

- 395: DECO

- ES

- 2628. Unpublished study prepared by Wildlife International Ltd. 138 p.

44192605 2050448

2050519 Beavers, J.; Chafey, K.; Foster, J. et al. (1995) XDE

- 564 Herbicide: A Reproduction Study with the Mallard (Anas

platyrhynchos): Lab Project Number: 103

- 396: DECO

- ES

- 2629. Unpublished study prepared by Wildlife International Ltd. 195 p.

72

- 1 Acute Toxicity to Freshwater Fish

MRID PDF # Citation Reference

43441012 2050449 Gorzinski, S.; Richardson, C .; Stahl, D.; et al (1993) XDE

- 564 Herbicide: Static Acute 96

- Hour Toxicity to the Bluegill, Lepomis macrochirus Rafinesque: Lab Project Number: DECO/ES/2504. Unpublished study prepared by The Dow Chemical Co. 25 p.

43441013 2050450

2050478 Gorzinski, S .; Richardson, C.; Stahl, D.; et al (1993) XDE

- 564 Herbicide: Static Acute 96

- Hour Toxicity to the Rainbow, Trout,

Oncorhynchus mykiss Walbaum: Lab Project Number: DECO/ES/2503. Unpublished study prepared by The Dow Chemical Co. 25 p.

### 30

44045203 Registrant

response Mayes, M. (1995) Response to U.S. EPA Data Evaluation Record of the Report "XDE

- 564 Herbicide: Static Acute 96

- Hour

Toxicity to the Rainbow Trout, Oncorhynchus mykiss Walbaum": MRID No. 434410

- 13: Lab Project Number: DECO

- ES

2981. Unpublished stu dy prepared by The Dow Chemical Co. 5 p.

72

- 2 Acute Toxicity to Freshwater Invertebrates

MRID PDF # Citation Reference

43441014 2050451

2050476 Brown, R.; Milazzo, D.; Servinski, M. et al. (1993) XDE

- 564 Herbicide: Acute Toxicity to the Dap hnia magna Straus: Lab

Project Number: DECO/ES/DR/0313/569: DECO/ES/2519. Unpublished study prepared by The Dow Chemical Co. 28 p.

44045202 Registrant

response Mayes, M. (1995) Response to U.S. EPA Data Evaluation Record of the Report "XDE

- 564 Herbicide: Acute Toxicity to the

Daphnid, Daphnia magna Straus": MRID No. 434410

- 14: Lab Project Number: DECO

- ES

- 2982R. Unpublished study prepared by The Dow Chemical Co. 5 p.

72

- 3 Acute Toxicity to Estuarine/Marine Organisms

MRID PDF # Citation Reference

43441015 2050452 Boeri, R.; Kowalski, P.; Ward, T. (1993) XDE

- 564 Herbicide: Acute Toxicity to the Silverside, Menidia beryllina: Lab Project Number: 192/DO: ES/2646. Unpublished study prepared by T.R. Wilbury Labs, Inc. 23 p.

43441016 2050453 Boe ri, R.; Kowalski, P.; Ward, T. (1993) XDE

- 564 Herbicide: Acute Flow

- Through Mollusc Shell Deposition Test: Lab Project Number: 191/DO: ES/2642. Unpublished study prepared by T.R. Wilbury Lab., Inc. 23 p.

43441017 2050454 Boeri, R.; Kowalski, P.; Ward, T . (1993) XDE

- 564 Herbicide: Acute Toxicity to the Grass Shrimp, Palaemonetes pugio: Lab Project Number: 190/DO: ES/2641. Unpublished study prepared by T.R. Wilbury Labs, Inc. 23 p.

72

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

MR ID PDF # Citation Reference

43441018 2050455 Brown, R.; Kirk, H.; Servinski, J. (1994) XDE

- 564 Herbicide: Evaluation of the Chronic Toxicity (21

- Day Flow

- Through) to the Daphnid, Daphnia magna Straus: Lab Project Number: 0313/5691: DECO/ES/2696. Un published study prepared by The Dow Chemical Co. 51 p.

122

- 1 Seed Germination/Seedline Emergence and Vegetable Vigor

MRID Citation Reference

PDF #

44656201 2050473

2050520 McCormick, R. (1998) Effect of Three Soil Metabolites of Diclosulam on the Emergence and Vegetative Vigor of Non

- Target

Terrestrial Plants (Tier I): Lab Project Number: ENV98049. Unpublished study prepared by Dow AgroSciences LLC. 123 p.

123

- 1 Seed germination/seedling emergence and vegetative vigor

MRID PDF # Cita tion Reference

44103537 2050457

2050458 Schwab, D. (1996) Evaluating the Effects of XDE

- 564 on the Seedling Emergence and Vegetative Vigor of Non

- Target

Terrestrial Plants: (Amended Final Report): Lab Project Number: 41705: RES94063: ABC 41705. Unp ublished study prepared by ABC Labs, Inc. 155 p.

123

- 2 Aquatic plant growth

### 31

MRID PDF # Citation Reference

44103538 2050459 Milazzo, D.; Kirk, H.; Humbert, L.; et al. (1995) The Toxicity of XDE

- 564 Herbicide to the Aquatic Plant, Duckweed, L emna gibba L. G

- 3: Lab Project Number: DECO

- ES

- 2806. Unpublished study prepared by Dow Chemical Co. 35 p.

44103539 2050460 Thompson, S.; Swigert, J. (1993) XDE

- 564 Herbicide: A 5

- Day Toxicity Test with the Marine Diatom (Skeletonema costatum): (Final Re port): Lab Project Number: 103A

- 106: ES

- 2665. Unpublished study prepared by Wildlife International Ltd. 39 p.

44103540 2050461 Thompson, S.; Swigert, J. (1993) XDE

- 564 Herbicide: A 5

- Day Toxicity Test with the Freshwater Diatom (Navicula pelliculosa): ( Final Report): Lab Project Number: 103A

- 107B: ES

- 2664. Unpublished study prepared by Wildlife International Ltd. 39 p.

44103541 2050462 Thompson, S.; Swigert, J. (1993) XDE

- 564 Herbicide: A 5

- Day Toxicity Test with the Freshwater Alga (Anabaena flos

- aqu ae): (Final Report): Lab Project Number: 103A

- 108A: ES

- 2663. Unpublished study prepared by Wildlife International Ltd. 41 p.

44103542 2050463 Kirk, H.; Miller, J. (1996) N

- (2,6

- Dichlorophenyl)

- 5

- hydroxy

- 7

- fluoro (1,2,4)Triazolo(1,5C)pyrimidine

- 2

- sulfon amide: The Toxicity to the Green Algae, Selenastrum capricornutum Printz: Lab Project Number: DECO

- ES

- 3093. Unpublished study prepared by Dow Chemical Co. 13 p.

44103543 2050464 Kirk, H.; Miller, J. (1996) N

- (2,6

- Dichlorophenyl)

- 8

- Chloro

- 7

- Fluoro

- 5

- (6H )

- Oxo (1,2,4) Triazolo (1,5C) Pyrimidine

- 2

- Sulfonamide: The Toxicity to the Green Algae, Selenastrum capricornutum Printz: Lab Project Number: DECO

- ES

- 3094. Unpublished study prepared by Dow Chemical Co. 15 p.

44103544 2050465 Kirk, H.; Miller, J. (199 6) 5

- Carboxymethyl

- N

- (2,6

- Dichlorophenyl)

- 1,2,4

- Triazole

- 3

- sulfonamide: Acute Toxicity to the Green Algae, Selenastrum capricornutum Printz: Lab Project Number: DECO

- ES

- 3095. Unpublished study prepared by Dow Chemical Co. 15 p.

44210701 2050466 Milazzo , D.; Servinski, M.; Weinberg, J. et al. (1992) XR

- 564 Herbicide: The Toxicity to the Green Alga, Selenastrum capricornutum Printz: Lab Project Number: ES

- 2518: DECO

- ES

- 2518. Unpublished study prepared by The Dow Chemical Co. 30 p.

44587805 2050467 Kirk , H.; Hugo, J.; Mcfadden, L. (1997) Phytotoxicological Evaluation of XDE

- 564 (BF

- 309 Formulation) with a Freshwater Green Algae, Selenastrum capricornutum Printz: Lab Project Number: 971132. Unpublished study prepared by Dow Chemical Company. 44 p.

44587 806 2050468 Kirk, H.; Gilles, M.; Rick, D. et al. (1998) Phytotoxicological Evaluation of 5

- Hydroxy

- DE

- 564 Exposed Saltwater Diatom, Skeletonema costatum: Lab Project Number: 980008. Unpublished study prepared by Dow Chemical Company. 35 p.

44587807 20 50469 Kirk, H.; Gilles, M.; Rick, D. et al. (1998) Phytotoxicological Evaluation of 5

- Hydroxy

- DE

- 564 Exposed Freshwater Diatom, Navicula pelliculosa: Lab Project Number: 980007. Unpublished study prepared by Dow Chemical Co. 35 p.

44587808 2050470 Kirk, H.; Gilles, M.; Rick, D. et al. (1998) Phytotoxicological Evaluation of 5

- Hydroxy

- DE

- 564 Exposed Aquatic Plant, Duckweed Lemna gibba L. G

- 3: Lab Project Number: 980009. Unpublished study prepared by Dow Chemical Company. 38 p.

44587809 2050471 Kirk, H. ; Gilles, M.; Hugo, J. et al. (1998) Phytotoxicological Evaluation of 5

- Hydroxy

- DE

- 564 Exposed Freshwater Green Algae, Selenastrum capricornutum Printz: Lab Project Number: 980011. Unpublished study prepared by Dow Chemical Company. 36 p.

44587810 20504 72 Kirk, H.; Gilles, M.; Hugo, J. et al. (1998) Phytotoxicological Evaluation of 5

- Hydroxy

- DE

- 564 Exposed Bluegreen Alga, Anabaena flos

- aquae: Lab Project Number: 980010. Unpublished study prepared by Dow Chemical Company. 35 p.

141

- 1 Honey bee acute contact

MRID PDF # Citation Reference

43441019 2050456 Hoxter, K.; Bernard, W.; Smith, G. et al. (1994) XDE

- 564 Herbicide: An Acute Contact Toxicity Study with the Honey Bee: Amended Report: Lab Project Number: 103/371B: 103/371: ES/2593. Unp ublished study prepared by Wildlife International Ltd. 24 p.

Non

- Guideline Studies

MRID PDF # Citation Reference

### 32

44103534 Registrant

assessment Mayes, M.; Wright, J. (1996) A Review of the Toxicity of Diclosulam (DE

- 564) Herbicide to Fish, Wildlif e, and Plants: Lab

Project Number: DECO

- ES

- 3141. Unpublished study prepared by DowElanco and Dow Chemical Co. 31 p.

44103535 DER not located Wright, J. (1996) Phytotoxicological Effects of XDE

- 564 and Its Soil Degradates: Lab Project Number: GH

- C 4139. U npublished study prepared by DowElanco. 35 p.

44587811 Registrant

Assessment Peterson, R.; Mayes, M.; Wesenbeeck, I. (1998) Aquatic and Terrestrial Risk Assessment for Diclosulam (DE

- 564) in the

Southeastern United States: Lab Project Number: GH

- C 4712 . Unpublished study prepared by Dow AgroSciences. 34 p.

43441020 DER not located Ward, T.; Magazu, J.; Boeri, R. (1994) Acute Toxicity of XDE

- 564 Herbicide to the Earthworm, Eisenia foetida: Amended Report: Lab Project Number: 84/DO: ES/2583. Unpublishe d study prepared by T.R. Wilbury Labs, Inc. 23 p.

N/A 2050481 Cover Memo for 29 Ecotoxicity Studies, March 2000

### 33 Appendix A2. OPPIN Bibliography for Environmental Fate Data

PC Code 129122 Diclosulam Fate/Chemistry Bibliography Fate Folder = F002422 Revised 29 July 2014

161

- 1 Hydrolysis

MRID PDF # Citation Reference

43441043 2052978

2052989 Batzer, F. (1994) Hydrolysis of XDE

- 564: Lab Project Number: ENV93082. Unpublished study prepared by DowElanco. 76 p.

161

- 2 Photodegradation

- water

MRID Citation Reference

43441044 2052979

2052989 Concha, M.; Shepler, K.; Merritt, D. (1994) Photodegradation of (carbon 14) XDE

- 564 in Buffered Aqueous Solution at pH 5 by

Natural Sunlight: Lab Project Number: 429W/1: 429W: ENV93099. Unpubli shed study prepared by PTRL West, Inc. 89 p.

161

- 3 Photodegradation

- soil

MRID Citation Reference

44192603 2052986 Concha, M.; Shepler, K.; Merritt, D. (1995) Photodegradation of (carbon

- 14)XDE

- 564 on Soil by Natural Sunlight: Lab Project Nu mber: ENV94058: 477W. Unpublished study prepared by PTRL West, Inc. 108 p.

162

- 1 Aerobic soil metabolism

MRID Citation Reference

43441045 2052980

2082981 2052989 Yoder, R. (1994) Aerobic Soil Degradation of XDE

- 564 N

- (2,6

- dichlorophenyl)

- 5

- ethoxy

- 7

- fluoro(1,2,4,)triazolo(1,5

- c)

pyrimidine

- 2

- sulfonamide: Lab Project Number: ENV93074R. Unpublished study prepared by DowElanco. 124 p.

44045201 2052980 Yoder, R. (1995) Aerobic Soil Degradation of XDE

- 564 of Norfolk Sandy Loam Soil: Supplemental to MRID 43441045 (Aerobic Soil Degradation of XDE

- 564: N

- (2,6

- dichlorophenyl)

- 5

- ethoxy

- 7

- fluoro(1,2,4)triazolo(1,5

- c)pyrimidine

- 2

- sulfonamide): Lab Project Number: ENV94103: ENV93074R. Unpublished study prepared by DowElanco's North American Environmenta l Chemistry Lab. 66 p.

44651201 2052988 Kennard, L.; Laskowski, D.; Schnelle, K. et al. (1996) Effect of Soil Temperature and Moisture on XDE

- 564 Degradation in Soil: Lab Project Number: GH

- C 3972. Unpublished study prepared by DowElanco. 188 p.

162

- 3 Anaerobic aquatic metabolism

MRID Citation Reference

44192604 2052987 Batzer, F.; Ostrander, J. (1996) Anaerobic Aquatic Degradation of XDE

- 564: Lab Project Number: ENV93114. Unpublished study prepared by DowElanco. 162 p.

162

- 4 Aero bic aquatic metabolism

### 34

MRID Citation Reference

44103530 2052983 Batzer, F.; Huskin, M. (1996) Aerobic Aquatic Metabolism of (carbon 14)

- DE

- 564: Lab Project Number: ENV96011. Unpublished study prepared by DowElanco. 90 p.

163

- 1 Leach/adsorpt ion/desorption

MRID Citation Reference

43471901 2052982

2052989 Cleveland, C.; Ostrander, J. (1994) Laboratory Mobility Assessment of XDE

- 564, 5

- OH XDE

- 564 and Aged Soil Degradates: Lab

Project Number: ENV94014. Unpublished study prepared by DowEla nco North American Environmental Chemistry Lab. 124
p.

44103529 DER not located Cryer, S.; Schnelle, K. (1996) Diclosulam Tier II Ground Water Vulnerability Exposure Assessment in the USA Soybean Markets: Lab Project Number: GH

- C 4142. Unpublished study prepared by DowElanco. 110 p.

164

- 1 Terrestrial field dissipation

MRID Citation Reference

44103531 2052984 Zabik, J.; Kennard, L.; Roberts, D.; et al. (1996) Terrestrial Field Dissipation of DE

- 564: Lab Project Number: ENV94021. Unpublished study prepared by DowElanco. 351 p.

44630601 2052985 Peacock, A.; Bormett, G. (1998) Terrestrial Field Dissipation of DE

- 564 in the Southeastern and Midwestern U.S.: Lab Project Number: ENV96021: GH

- C 4131: 1097. Unpublished study prepared by Dow AgroSci ences LLC., and Alvey Agricultural Research. 524 p.

49071902 DER not located Dyer, D.; Xu, T. (2014) Waiver of the Requirement for Terrestrial Field Dissipation on Turf

- Fluopyram. Project Number: M/483769/01/2, US0417. Unpublished study prepared by Bay er CropScience LP. 10p.

164

- 2 Aquatic field dissipation

MRID Citation Reference

44587802 2052985 Eckert, J. 1998. Independent laboratory validation of method GRM 96.22.Rl

- determination of residues of diclosulam and aminosulfonyl triazolopy rimidine (ASTP) degradate in soil by capillary gas chromatography with mass selective detection. Laboratory Study ID: DE

- 06

- 97. Unpublished study performed by Enviro

- Bio

- Tech, Ltd., Bernville, PA; and submitted by Dow AgroSciences LLC, Indianapolis, IN.

4 4587803 2052985 Duebelbeis, D. (1998) Method Validation Report for GRM 97. 10

- Determination of Diclosulam in Water by Capillary Gas Chromatography with Mass Selective Detection: Lab Project Number: RES97118. Unpublished study prepared by Dow AgroSciences L LC. 38 p.

44587804 2052985 Kaiser, F.; Duebelbeis, D. (1998) Independent Laboratory Validation of Method GRM 97.10

-- Determination of Diclosulam in Water by Capillary Gas Chromatography with Mass Selective Detection: Lab Project Number: 44441: RES97123. U npublished study prepared by ABC Laboratories, Inc. 72 p. {850.7100}

165

- 1 Confined rotational crop

MRID Citation Reference

44103501 Check with HED Stafford, L. (1996) Interpretive Summary of Diclosulam (DE

- 564) Soybean Residue Chemistry: L ab Project Number: GH

- C 4127. Unpublished study prepared by DowElanco North American Environmental Chemistry Lab. 17 p.

44103532 Check with HED Lardie, T.; Stafford, L. (1996) A Confined Rotational Crop Study with (carbon 14)XDE

- 564 Using Wheat, Lettuce, and Potatoes: Lab Project Number: MET93004: 93.192. Unpublished study prepared by Plant Sciences, Inc. and DowElanco. 140 p.

### 35

44103529 Registrant Assessment Cryer, S.; Schnelle, K. (1996) Diclosulam Tier II Ground Water Vulnerability Exposure Assessment in the USA Soybean Markets: Lab Project Number: GH

- C 4142. Unpublished study prepared by DowElanco. 110 p.

Non

- Guideline Studies

MRID Citation Reference

44103528 DER not

located Yoder, R. (1996) Summary of th e Environmental Fate of DE

- 564: Lab Project Number: GH

- C 4131. Unpublished study prepared by DowElanco. 52 p.

44587801 Jachetta, J. (1998) Supplemental Information for Establishment of Diclosulam Tolerances in Soybeans and Peanuts under the Requirements of the Food Quality Protection Act of 1996: Lab Project Number: JJJ061098. Unpublished study prepared by DOW AgroSciences LLC. 10 p.

44587811 Peterson, R.; Mayes, M.; Wesenbeeck, I. (1998) Aquatic and Terrestrial Risk Assessment for Diclosulam (DE

- 564) in the Southeastern United States: Lab Project Number: GH

- C 4712. Unpublished study prepared by Dow AgroSciences. 34 p.

44593401 Jaschetta, J.; van Wesenbeeck, I.; Cordes, R. et al. (1998) Reduced Risk Rationale for Diclosulam Herbicide Used in the Con trol of Broadleaf Weeds in Peanuts: Lab Project Number: JJJ062698. Unpublished study prepared by Dow AgroSciences LLC. 175 p.

45173103 Richburg, J. (1997) The Crop Tolerance and Yield of Soybeans When Strongarm is Used Sequentially with Other ALS Herbici des in the Same Season or when Used Alone Over One or Two Seasons in Coastal U.S.

-- 1996

- 1997: Lab Project Number: NA97I3A031: NA97I3A032: NA96I3A015. Unpublished study prepared by Dow AgroSciences LLC. 23 p.

45606801 Herrera, R. (2002) A Summary of the Non

- Destruct Experimental Use Program 62719

- EUP

- 49 for Use on Peanuts: BF

- 309/XDE

- 564 (Diclosulam): Lab Project Number: RH013102. Unpublished study prepared by Dow AgroSciences LLC. 7 p.

### 36 Appendix B

. S TIR Model Output

Welcome to the EFED

Input

Application and Chemical Information

Enter Chemical Name Diclosulam

Enter Chemical Use Soybean Is the Application a Spray? (enter y or n) y If Spray What Type (enter ground or air) ground Enter Chemical Molecular Weight (g/mole) 406 Enter Chemical Vapor Pressure (mmHg) 5.00E

- 15 Enter Application Rate (lb a.i./acre) 0.0315

Toxicity Properties

Bird

Enter Lowest Bird Oral LD 50 (mg/kg bw) 2250 Enter Mineau Scaling Factor 1.15 Enter Tested Bird Weight (kg) 0.1 78
Mammal

Enter Lowest Rat Oral LD 50 (mg/kg bw) 5000

Enter Lowest Rat Inhalation LC 50 (mg/L) 5.04 Duration of Rat Inhalation Study (hrs) 4 Enter Rat Weight (kg) 0.35

Output
Results Avian (0.020 kg )
Maximum Vapor Concen tration in Air at Saturation (mg/m 3 ) 1.09E

- 10

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 1.37E

- 11
Adjusted Inhalation LD 50 1.26E+01
Ratio of Vapor Dose to Adjusted Inhalation LD 50 1.09E

- 12 Exposure not Likely Significant

Maximum Post

- treatmen t Spray Inhalation Dose (mg/kg) 3.33E

- 03
Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 2.63E

- 04 Exposure not Likely Significant

Results Mammalian (0.015 kg ) Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 1.09E

- 10

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 1.73E

- 11
Adjusted Inhalation LD 50 3.00E+02
Ratio of Vapor Dose to Adjusted Inhalation LD 50 5.75E

- 14 Exposure not Likely Significant

Maximum Post

- treatment Spray Inhalation Dose (mg/kg) 4.18E

- 03

Ra tio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 1.39E

- 05 Exposure not Likely Significant

### 37 Appendix C. SIP Model Output

Table 1. Inputs
Parameter Value
Chemical name Diclosulam Solubility (in water at 25 o C; mg/L) 4290

M ammalian LD 50 (mg/kg

- bw) 5000 Mammalian test species laboratory rat Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg

- bw) 10 Mammalian test species other Body weight (g) of "other" mammalian species 2500

Avian LD 50 (mg/kg

- bw) 2250 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) 1000
Table 2. Mammalian Res ults
Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 737.8800 737.8800 Adjusted toxicity value (mg/kg

- bw) 3845.8028 12.5743 Ratio of exposure to toxicity 0.1919 58.6814

Conclusion* Exposure through drinking water alone is a potential
conce rn 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) 3474.9000 3474.9000 Adjusted toxicity value (mg/kg

- bw) 1620.9664 2.4806
R atio of exposure to acute toxicity 2.1437 1400.8146

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 for effects to non

- target anima ls.

### 38 Appendix D. Table of Reported Incidents for Diclosulam from EIIS

PC Cod

e Comm

on Name Typ

e Incid
ent ID Use Site Start Date Legality Certa

inty Cou ntry Sta
te Count
y Ye

ar Terr
est. Plan
t To tal No

. Total Magni tude Appl. Rate Appl. Method Air/

Gnd Formul ati on Product Com

pany # Prod
uct # Di
st. # Wea ther Seas

on

129 122 Diclos ulum PLA NTS I010 927

- 054 FIEL D 5/10/ 2000 REGISTE RED USE Possi

ble USA TX COCH

RAN 20 00 Yes 29

0 0.45

GALS/ ACRE Broadcas
t Gnd N/R STRON GARM Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 015 PEA NUT 5/6/2 000 REGISTE RED USE Prob able USA TX 20 00 Yes ALL 0.45

OZ/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 018 PEA NUT 5/1/2 000 REGISTE RED USE Prob able USA TX DAWS

ON 20 00 Yes ALL 0.45

OZ/AC RE BAND N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 022 PEA NUT 4/28/ 2000 REGISTE RED USE Possi

ble USA TX DAWS

ON 20 00 Yes ALL 0.45

OZ/AC RE BAND; AT PLANT N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 023 PEA NUT 5/2/2 000 REGISTE RED USE Prob able USA TX DAWS

ON 20 00 Yes ALL 0.45

OZ/AC
RE BAND, PREEME RGENT N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 024 PEA NUT 5/11/ 2000 REGISTE RED USE Prob able USA TX YOAK

UM 20 00 Yes ALL 0.45

OZ/AC
RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 D iclos ulum PLA NTS I010 936

- 025 PEA NUT 5/12/ 2000 REGISTE RED USE Prob able USA TX GAINE

S 20 00 Yes ALL 0.45

OZ/AC
RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 026 PEA NUT 4/27/ 2000 REGISTE RED USE Prob able USA TX GAINE

S 20 00 Yes ALL 0.45

OZ/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 027 PEA NUT 5/9/2 000 REGISTE RED USE Prob able USA TX GAINE

S 20 00 Yes ALL 0.45

OZ/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 02 8 PEA NUT 5/10/ 2000 REGISTE RED USE Prob able USA TX GAINE

S 20 00 Yes ALL 0.45

OZ/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 029 PEA NUT 5/3/2 000 REGISTE RED USE Prob able USA TX TERRY 20 00 Yes ALL 0.45

OZ.AC RE Broadcas
t Gn d N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 030 PEA NUT 5/1/2 000 REGISTE RED USE Prob able USA TX DAWS

ON 20 00 Yes ALL 0.45

OZ/AC
RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 031 PEA NUT 5/3/2 000 REGISTE RED USE Prob able USA TX GAINE

S 20 00 Yes ALL 0.45

OZ/AC
RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 032 PEA NUT 5/1/2 000 REGISTE RED USE Prob able USA TX COCH

RAN 20 00 Yes ALL 0.45

OZ/AC
RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 033 PEA NUT 5/1/2 000 REGISTE RED USE Prob able USA TX GAINE

S 20 00 Yes 210

ACRES 0.45 OZ/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 035 PEA NUT 5/9/2 000 REGISTE RED USE Prob able USA TX HO CKL

EY 20 00 Yes ALL 0.45

OZ/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 036 PEA NUT 5/15/ 2000 REGISTE RED USE Prob able USA TX YOAK

UM 20 00 Yes ALL

120 ACRES 0.45 OZ/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 D iclos ulum PLA NTS I010 936

- 037 PEA NUT 5/15/ 2000 REGISTE RED USE Prob able USA OK YOAK

UM 20 00 Yes ALL 0.45

OZ/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 039 PEA NUT 5/8/2 000 REGISTE RED USE Prob able USA OK JOHNS

TON 20 00 Yes ALL 0.45

OZ/AC
RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

### 39

PC Cod

e Comm

on Name Typ

e Incid
ent ID Use Site Start Date Legality Certa

inty Cou ntry Sta
te Count
y Ye

ar Terr
est. Plan
t To tal No

. Total Magni tude Appl. Rate Appl. Method Air/

Gnd Formul ati on Product Com

pany # Prod
uct # Di
st. # Wea ther Seas

on

129 122 Diclos ulum PLA NTS I010 936

- 040 PEA NUT 5/11/ 2000 REGISTE RED USE Prob able USA TX YOAK

UM 20 00 Yes ALL 0.45

OZ/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 041 PEA NUT 4/28/ 2000 REGISTE RED USE Prob able USA TX GAINE

S 20 00 Yes ALL 0.45

OZ/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 042 PEA NUT 5/1/2 000 REGISTE RED USE Prob able USA TX HOCKL

EY 20 00 Yes ALL 0.45

OZ/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 043 PEA NUT 5/6/2 000 REGISTE RED USE Prob able USA TX LUBB

OCK 20 00 Yes ALL 0.45

OZ/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 044 PEA NUT 5/2/2 000 REGIST E RED USE Prob able USA TX HOCKL

EY 20 00 Yes ALL 0.45

OZ/AC
RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 045 PEA NUT 4/30/ 2000 REGISTE RED USE Prob able USA TX LUBB

OCK 20 00 Yes ALL 0.45

OZ/AC
RE Broadcas
t Gnd N/R STRON GARM N/ R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 048 PEA NUT 5/8/2 000 REGISTE RED USE Prob able USA OK JOHNS

TON 20 00 Yes ALL 0.45

OZ/AC
RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 049 PEA NUT 4/27/ 2000 REGISTE RED USE Prob able USA N

M LEA 20

00 Yes ALL 0.45

OZ/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 050 PEA NUT 4/26/ 2000 REGISTE RED USE Prob able USA TX GAINE

S 20 00 Yes ALL 0.45

OZ/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 051 PEA NUT 4/28/ 2000 REGISTE RED USE Prob able USA TX CROSB

Y 20 00 Yes ALL 0.45

OZ/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 053 PEA NUT 4/22/ 2000 REGISTE RED USE Prob able USA TX GAINE

S 20 00 Yes ALL 0.45

O Z/AC RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 055 PEA NUT 5/11/ 2000 REGISTE RED USE Prob able USA TX TERRY 20 00 Yes ALL 0.45

GAL/A CRE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 056 Pean
ut 5/8/2 000 REGISTE RED USE Prob able USA TX COCH

RAN 20 00 Yes ALL 0.45

OZ/AC
RE Broadcas
t Gnd N/R STRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I010 936

- 057 Pean
ut 4/29/ 2000 REGISTE RED USE Prob able USA TX GAINE

S 20 00 Yes ALL 0.45

OZ/AC
RE Broadcas
t Gnd N/R S TRON GARM N/R Sprin
g

129 122 Diclos ulum PLA NTS I011 838

- 111 Pean
ut 6/2/2 001 Undeter mined Possi

ble USA GA 20 01 Yes 26

acres Stronga

rm Sum

mer

129 122 Diclos ulum PLA NTS I011 942

- 002 Pean
ut 6/2/2 001 Undeter mined Possi

ble USA GA 20 01 Yes ALL N/R N/R N/R STRON GARM N/R Sum

mer

129 122 Diclos ulum PLA NTS I012 366

- 002 Pean
ut 5/5/2 000 Register ed use Prob

able USA OK TILLM

AN 20 00 Yes 30

acres 0.45 oz/acr

e Broadcas
t Gnd Stronga

rm 6271

9 288 Sprin

g

129 122 Diclos ulum PLA NTS I016 828

- 002 Pean
ut 9/27/ 2005 Re gister ed use Possi

ble USA N

M Roose velt 20 05 Yes Unkno

wn Granul

ar Stronga

rm 6271

9 288 Autu

mn