UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

OFFICE OF

CHEMICAL SAFETY AND

POLLUTION PREVENTION

PC Code: 109801

DP Barcode: D359480, 357471

Date: February 28,2012

Dee.t'ilun'. ?44570

MEMORANDUM

Subject:

To:

Refined iprodione drinking water assessment for label amendments and proposed new

uses on fruiting vegetables and cucurbits.

Lisa Jones, Reviewer

Tamue Gibson, Reviewer

Mary Waller, Risk Manager

Fungicides Branch

Registration Division (7505P)

From:

Donna Davis, Risk Assessor

Michael Metzger, Branch Chief

Risk Assessment Branch 7

Health Effects Division (7509P)

Chuck Peck, Environmental Engineer

Environmental Risk Branch IV

Environmental Fate and Effects Division (7507P)

Reviewed b~:.a)"im Carleton, Ph.D., Senior Scientist t1I\A tv-- ~( z,,,( ll.

11''' Environmental Risk Branch N

Environmental Fate and Effects Division (7507P)

Approved by: Marietta Echeverria, Branch Chief tVvt - z.,( 1..'" ( It.

Environmental Risk Branch N

Environmental Fate and Effects Division (7507P)

EXECUTIVE SUMMARY

The Environmental Fate and Effects Division (EFED) conducted a drinking water

assessment (DWA) for iprodione in response to label amendments and proposed new uses on

fruiting vegetables and cucurbits. The estimated drinking water concentrations (EDWC) have

'1.1•••111

2086812

TEXT SEARCHABLE DOCUMENT 2012
been revised and replace previously reported values. The revisions and refinements in this

assessment are to account for residues of concern that were not considered in the previous

DWAs, and in response to comments on the previous DWA provided by the registrant

(D385307+, April 5, 2011).

New uses proposed on the Enclosure label (Reg. No. 86153-3) include cucurbits applied

at a single maximum application rate of 2 lbs ai/A, with a maximum seasonal application rate of

3 lbs ai/A and a minimum retreatment interval of 12 days. For fruiting vegetables, the single

maximum application rate is 3 lbs ailA, with a maximum seasonal application rate of 3 lbs ailA.

If an application is made at less than the single maximum application rate, a minimum

retreatment interval of 12 days is required. For peanuts, the single maximum application rate is

1.5 lbs ailA, with a maximum seasonal application rate of 3 lbs ailA and a minimum retreatment

interval of 14 days.

Previously, EFED calculated estimated drinking water concentrations (EDWCs) for

iprodione and the iprodione degradate 3,5-dichloroaniline (3,5-DCA) (D385307+, April 5,

2011). Acute concentrations for iprodione from all ofthe modeled crops (excluding rice) were in

the range of 0.03 to 361 ug/L; chronic concentrations were in the range of 0.0 to 3.5 ug/L; and

cancer concentrations were in the range of 0.0 to 1.6 ug/L. Acute concentrations for 3,5-DCA

from all of the modeled crops (excluding rice) were in the range of 0.05 to 153 ug/L; chronic

concentrations were in the range of 0.03 to 56 ug/L; and cancer concentrations were in the range

of 0.01 to 36 ug/L. Groundwater concentrations for the highest annual use of iprodione (24 lbs

ai/A) were 25.4 and 1.1 ug/L for iprodione and 3,5-DCA, respectively.

Since the previous assessment (April 2011), EFED received comments from the

registrant, and had discussions with HED regarding residues of concern, which have changed the

inputs and conclusions of the previous drinking water assessment. In particular, in response to

comments received from the registrant, EFED has no longer included the unextracted residues in

the estimation of the aerobic soil metabolism half-life for iprodione residues. EFED has also

refined assumptions ofthe proportion of maximum iprodione residues relative to 3,5-DCA based

on information from metabolism studies. Specifically, EFED has assumed that 75% of the

iprodione applied is converted to 3,5-DCA, with 25% of the applied iprodione available for

runoff. Lastly, based on the findings of the Residues of Concern Knowledge Subcommittee

(ROCKS), three new degradates, RP30228 {3-(l-methylethyl)-N-(3,5-dichlorophenyl)-2,4-

dioxo-1-imidazolidine-carboxamide}, RP35606 {[(dichloro-3,5-phenyl)-1-isopropylcarbamoyl3]-2-acetic acid}, and RP32490 {3-(3,5-dichlorophenyl)-2,4-dioxo-1-imidazolidinecarboxamide}, were included as residues of concern related to the parent iprodione (D393960,

October 5, 2011). As such, half-lives for the hydrolysis, aerobic soil, aerobic aquatic, and

anaerobic aquatic metabolism studies were recalculated using a total toxic residue (TTR)

approach for iprodione, RP30228, RP35606 and RP32490. Chemical and fate input parameters

for 3,5-DCA did not otherwise change.

Tables 1 and 2 list the EDWCs for the proposed new uses and the highest existing uses

for total toxic residues of iprodione and the degradate 3,5-DCA, respectively. Acute

concentrations for total toxic residues ofiprodione from all ofthe modeled crops (excluding rice)

are in the range of 0.01 to 92 ug/L; chronic concentrations are in the range of 0.0 to 31 ug/L; and

2
cancer concentrations are in the range of 0.0 to 18 ug/L, Acute concentrations for 3,5-DCA from

all of the modeled crops (excluding rice) are in the range of 0.04 to 115 ug/L; chronic

concentrations are in the range of 0.02 to 42 ug/L; and cancer concentrations are in the range of

0.01 to 27 ug/L. Groundwater concentrations for the highest annual use of iprodione (24 lbs

ai/A) are 0.29 and 0.81 ug/L for total toxic residues ofiprodione and 3,5-DCA, respectively. A

complete listing of EDWCs for all labeled uses can be found in Tables 11 and 15. The EDWCs

for rice are unrefined Tier I estimates and are not appropriate for estimations of chronic and

cancer risk without further refinement. Other than rice, the highest EDWCs represent modeled

use on turf at the maximum application rate of 24 lbs ailAzyear.

Table 1. Selected estimated drinking water concentrations for total toxic residues of

rprodOtone

Drinking Use Seasonal I-in-IO I-in-IO 30- year

water source application year year average

rate (Ibs ai/A) acute chronic (I!g/L)

(/lglL) (/lgIL)

Surface Water Fruiting vegetables (new use) 3 x I Ib ai/A 25 3.3 2.2

Surface Water Cucurbits (new use) 3 x I lbai/A 36 3.5 1.7

Surface Water Peanuts (label revision) 2 x 1.5 lb ai/A 23 5.5 2.5

Surface Water Turf 6 x 4 lb ai/A 92 31 18

Surface Water Rice lib ai/A 175 < 175 < 175

Groundwater Turf 241bai/A 0.29 0.29 0.29

Table 2. Selected estimated drinking water concentrations for the iprodione degradate 3,5-

DCA resuItinz tm2 from appirications 0 f"rprodiione

Drinking Use Seasonal I-in-IO I-in-IO 30- year

water source application year year average

rate (lbs ai/A) acute chronic (l!glL)

(/l21L) (/l21L)

Surface Water Fruiting vegetables (new use) 3 x I Ib ai/A 36 5.4 3.8

Surface Water Cucurbits (new use) 3 x I Ib ai/A 32 4.2 2.3

Surface Water Peanuts (label revision) 2 x 1.5 Ib ai/A 24 6.0 4.0

Surface Water Turf 6 x 41b ai/A II5 42 27

Surface Water Rice 1 Ib ai/A 21 I < 211 < 21 I

Groundwater Turf 24 Ib ai/A 0.81 0.81 0.81

EFED evaluated monitoring data from national studies not targeted to iprodione use areas

in addition to targeted studies submitted by the registrant. The majority of the non-targeted

monitoring samples (>98%) collected for iprodione and 3,5-DCA were below levels of detection.

Maximum detected concentrations of iprodione in surface and ground water monitoring were 45

and 5.75 ug/L, respectively (Table 6). Concentrations of 3,5-DCA in surface and ground water

monitoring were less than (or equal to) 0.09 and 0.1 ug/L, respectively (Table 6). However,

variations in reporting and detection limits introduce uncertainty into these results. Additionally,

as this monitoring was not targeted specifically at iprodione use areas or times of known

iprodione use, the monitored concentrations are unlikely to reflect maximum iprodione

concentrations that may occur in surface waters, such as when runoff events occur shortly after

application. Additionally, the three new residues of concern that are included in the modeling

were not analyzed in any of the monitoring studies, so these concentrations may underestimate

total iprodione residues of concern.

3
Targeted surface water sampling (MRIDs 47579101 and 47881501) associated with turf

applications of iprodione conducted by Bayer Cropscience from 2006 to 2009 found maximum

concentrations of iprodione and 3,5-DCA that were less than or equal to 0.56 and 0.1 ug/L,

respectively. However the iprodione application rates employed during this study were

apparently four orders of magnitude less than the maximum allowable 24 lbs ai/A (which was

used in the modeling). Additionally, the three new residues of concern were not included in this

focused monitoring study.

PROBLEM FORMULATION

This drinking water assessment is being conducted for iprodione total toxic residues

(TTR) and its degradate, 3,5-DCA, in response to label amendments and proposed new uses on

fruiting vegetables and cucurbits. The revisions and refinements in this assessment take into

account to comments on the previous DWA provided by the registrant (D385307+, April 5,

2011) and residues of concern that were not considered in the previous DWAs.

In their comments, the registrant indicated that, as EPA had in the past considered 3,5-

DCA the terminal degradate for iprodione and aerobic soil metabolism studies conducted using

3,5-DCA had indicated that it eventually became bound to the soil over time, unextractable

residues should not be included in the estimation of the aerobic soil metabolism half-life for

iprodione. 3,5-DCA has been detected in aerobic soil and aerobic and anaerobic aquatic

metabolism studies. While the submitted degradation studies conducted on 3,5-DCA reported

large amounts of unextracted and uncharacterized material, EFED concluded, following a review

of the extraction method, that under aerobic conditions 3,5-DCA either binds to soil or is

transformed to other unextracted residues that are not available to off-site transport (D357470+,

12/30/2009; D386316+, 2/16/2011). Based on this information, EFED has agreed with the

registrant's comment and has removed the unextractable residues from the iprodione TTR

aerobic soil metabolism half-life estimate.

In the previous assessment, EFED conservatively assumed 100% of the iprodione was

converted to 3,5-DCA. However, if this were the case, then EDWCs should only be developed

for 3,5-DCA, as no iprodione would remain. In the current refinement, EFED has used the

findings from the aerobic soil metabolism study (MRID 43091002) which indicated up to 75% of

unextractable residues were formed in the study. Based on 3,5-DCA's ability to bind to soil,

EFED assumed that the 75% of unextractable residue from the aerobic soil metabolism study is

3,5-DCA. As such, the EDWCs generated in this assessment assume that 75% of the applied

iprodione is converted to 3,5-DCA and the remaining 25% of applied remains as iprodione TTR

on the field, available for transport in runoff. Actual conversion percentages lie between the

extremes of 0 and 100% conversion of iprodione to 3,5-DCA. EFED believes that the

assumption of 75% conversion is a realistic refinement based on the limited aerobic soil

metabolism data.

On September 14, 2011, the Health Effects Division (HED) Residues of Concern

Knowledge Subcomittee (ROCKS) reconvened on iprodione to reconsider metabolites and

degradates that were being included in the risk assessment and tolerance expression for iprodione

4
in plant and livestock commodities, but not in the drinking water assessment. Based on that

results ofthat meeting, the following degradates were found to be oftoxicological concern: 3,5-

DCA (RP32596), RP30228, RP35606, and RP 32490. 3,5-DCA is considered to have a

genotoxic mode of tumor induction based on its similarity to its structural analog

parachloroaniline, which is carcinogenic in animal carcinogenicity studies (USEPA, 1998).

HED's ROCKS identified the remaining degradates as residues of concern (1) due to their

presence as major degradates in the hydrolysis, aerobic aquatic, and anaerobic aquatic

metabolism studies and (2) their structural similarities to the parent, indicating similar toxicity to

the parent. HED's ROCKS concluded that "By including these precursor degradates in the risk

assessment with parent iprodione and conducting a separate assessment for 3,5-DCA, the overall

approach should be sufficiently conservative and protective of the assessed risks including those

for cancer" (D393960, October 5,2011).

This drinking water assessment uses modeling to provide estimates of surface water and

groundwater concentrations for iprodione total toxic residues (TTR) and 3,5-DCA in source

water for drinking water (pre-treatment) resulting from iprodione labeled uses. Routes of

transport to source water are primarily from runoff, leaching, and spray drift. The coupled

models PRZM and EXAMS were used to assess exposure in surface water due to runoff and drift

from the proposed and existing iprodione uses. Exposure concentrations in groundwater due to

leaching were assessed with the screening model SCI-GROW. Exposure concentrations

resulting from applications to rice were assessed with the unrefined Tier I Rice Model.

In addition to modeling estimates, this drinking water assessment considers monitoring

data from available sources. This includes data from non-targeted data, including the US

Geological Survey's National Ambient Water Quality Assessment (NAWQA) database, the

California Department of Pesticide Regulation's surface water database, and the Suffolk County,

New York groundwater monitoring program, and data from a 3-year monitoring study to

ascertain the levels ofiprodione and 3,5-DCA in raw and finished drinking water in areas of high

turf use (MRIDs 47579101 and 47881501).

ANALYSIS

Use Characterization

Iprodione [3-(3,5-dichlorophenyl)-N-(1-methylethyl)-2,4-dioxo-1-imidazolidinecarboxamide] is a contact and/or locally systemic fungicide. Application methods include aircraft aerial

applications, groundsprays, chemigation, and dipping. It is registered for use on a variety of

fruits, vegetables, turf and ornamentals. The registrant is proposing to add new uses on fruiting

vegetables and cucurbits, as well as modifications to the uses on peanuts. The current formulations are

for outdoor use only.

EFED reviewed all relevant labels for the pertinent information on uses. EFED

conducted model simulations for most ofthe labeled uses (in some cases multiple scenarios for a

given use) in order to derive EDWCs. Some ofthe uses could not be directly simulated but were

addressed using surrogate scenarios (e.g., California almond used for pistachio and Florida

cabbage for Florida Chinese Mustard). The simulations that were performed were sufficiently

broad to provide a realistic assessment ofthe varied uses ofiprodione.

5
Environmental Fate and Transport Characterization

Iprodione is moderately mobile (FAO soil mobility classification) in soil systems with a

Koc around 500 ml/g. It is not volatile and, as such, is not subject to long-range aerial transport.

Iprodione is most persistent in acidic environments, with half-lives around 130 days at pH 5 in

aquatic systems; however, in neutral aquatic systems, the half-life is only 4.7 days (pH 7), and in

alkaline systems, iprodione quickly degrades (27 minutes at pH 9). In aquatic systems, iprodione

degradation occurs primarily via hydrolysis. In an aquatic photolysis study, iprodione degraded

slowly with a half-life of 67 days in a pH 5 buffered solution, with no major degradates (~10%

ofthe applied) observed.

Submitted iprodione soil degradation studies show high levels of unextracted and

unidentified residues. This leads to uncertainty in characterization ofthe chemical's degradation.

In an aerobic soil degradation study (MRID 43091002), 75-87% ofthe residues at day 276 were

unextracted and uncharacterized. Unextractable residues exceeded 10% of applied between days

14 and 30 of the study. Thus the extent to which these residues constitute parent iprodione or

degradates of concern remains unknown. However, based on 3,5-DCA's affinity to bind to soil

or be transformed to other unextracted residues that are not available to off-site transport, and the

that 3,5-DCA is considered the terminal degradate in iprodione metabolism studies, EFED

assumed that the unextracted and uncharacterized residues in the iprodione soil studies were 3,5-

DCA and used this information to estimate an upper bound conversion rate of 75% of iprodione

to 3,5-DCA. In terrestrial and aquatic field dissipation studies, iprodione dissipated with DT50s

of 3 to 7 days, at pH values (6.2-8) which suggest that hydrolysis may have been a contributing

factor. However because ofthe extraction concerns raised in the soil studies, the extent to which

these DT50 values represent decay rather than temporary sequestering ofiprodione (or degradates

of concern) is not known.

A summary of major degradates observed in laboratory and field studies, their structures,

and proposed degradation pathways is provided in Appendix 1. Appendix 1 also lists the

degradates by study type, and the maximum percent of applied at which each of the degradates

was detected. HED has identified degradates 3,5-DCA (RP32596), RP30228, RP35606, and

RP32490 as residues of concern (D393960, October 5, 2011). Based on recommendations from

the ROCKS, iprodione, RP30228, RP35606, and RP32490 are therefore evaluated by EFED as

total toxic residue (TTR), separate from the evaluation of 3,5-DCA. Thus this assessment

considers the exposure to both iprodione TTR and 3,5-DCA. When the three degradates are

included, the half-lives of the TTR increase dramatically beyond that of the parent. The

hydrolysis half-lives are 772 days at pH 5, 266 days at pH 7, and 56 days at pH 9. The aerobic

aquatic half-life becomes 60.7 days, and the anaerobic half-life becomes 92 days. The aerobic

soil metabolism half-life of TTR remains almost the same as that of the parent chemical, at 19.2

days. However this result is based on a single aerobic soil metabolism study, and the half-life

does not take into account the high levels of unextracted residues, which are assumed to consist

entirely of 3,5-DCA.

Table 3 summarizes the general fate properties of iprodione parent and total toxic

residues (TTR) based on submitted studies, and Table 4 presents the properties of 3,5-DCA.

Summaries ofthe available information are presented in the following sections.

6
Table 3. Summary of general fate properties of iprodione and total toxic residues of

concern

Property Value SourcelMRID Comments

Molecular formula C13HI3ChN30 3 Formula reported for iprodione

Molecular weight (g/mole) 330.2 Value reported for iprodione

Vapor pressure (Torr, 20°C) 2.7xlO-7 Iprodione Value reported for iprodione

RED

Henry's Law Constant 9.0xlO·9 calculated =(vp/760)/(MW/sol); vp in

(atm m3/mol) Torr; sol in mg/L; MW in g/mol

Octanol/Water Coefficient 3.1 47778802 Value reported for iprodione

(Log Kow nOC)

Solubility in water (mg/L, 20°e) 13 47778802

pH Parent TTR Study conducted for 30 days

Hydrolysis half- life (days) 5 131 772 41885401 (pH 5), 125 hours (pH 7), and

7 4.7 266 121 minutes (pH 9).

9 0.02 56

Aqueous photolysis half- life 64 (parent and TTR) 41861901 (days)

Parent TTR High amounts of unextracted

Aerobic soil half-life (days) 43091002 1 material (75-87%). These

16 19.2 residues are assumed to be 3,5-

DCA.

Aerobic aquatic half-life (days) Parent TTR 419276011 pH = 8.5

9 60.7 42503801

Anaerobic aquatic half-life (days) Parent TTR 41755801 11 92

223(sandy loam) Values reported for iprodione

Organic carbon partitioning 432 (loamy sand) 43349202 coefficient (Koc) (mUgoc) 507 (loam)

543 (clay)

Terrestrial field dissipation DT50

Parent TTR CA - silt loam CA 7 28 41877401 (days) NC <3 <3 NC - loamy sand

Water Values reported for iprodione

3.7 days (TX)

Aquatic field dissipation DT50

2.9 days (MS) 43718301 Sediment

3.4 months (TX)

4.1 months (MS)

1. A second aerobic soil metabolism study (MRID 44590501) was conducted III 1993. However the study was

classified as supplemental because nonextractable e4

C]residues and volatiles were not measured, so a material

balance could not be determined.

Table 4 S. ummary 0 ffate propertires 0 fthe rpro . d'ione degrada et 35, -DCA

Property Value SourcelMRID Comments

Molecular wt 162 Product chemistry data

Solubility (mg/L) 784 EPI Suite

Vapor pressure 8.5xlO-3 EPI Suite

(Torr, 25°e)

Henry's Law Constant 10-b EPI Suite

(atm m3/mol)

Aerobic soil half-life 50.2 (sandy loam) 43091002 High levels of unextracted

7
Property Value SourcefMRID Comments

(days) 7.9 (silt loam) 45239201 residues (see text). Half- !

17.6 (sandy loam) lives do not include

I 49 (silt loam) 48219201 (8.3 mg/kg applied) unextracted residues

107 (sand) based on extensive

40 (silt loam) 48219201 (1.47 mg/kg applied) extraction techniques.

59 (sand)

Organic carbon 380 (silt foam) 45114101

partitioning coefficient 593 (sandy loam)

(Koc) (mL/goc) 626 (loamy sand)

788 (pond sediment, sand)

932 (clay)

Terrestrial Field Dissipation

Two terrestrial field dissipation studies are available (both described in MRID

41877401). Neither study monitored for the degradate 3,5-DCA, but did monitor for the

degradates RP30228 and RP32490. The two studies were conducted in California and North

Carolina and are summarized below.

In the San Juan Bautista, CA study, iprodione was applied 8 times to carrots at 1 lb

ailA/application. Iprodione dissipated with an observed DT50 of 7 days in the 0-15 cm soil layer

of a silt loam soil (pH 7.9-8.0). The degradates RP30228 and RP32490 were detected at 0-15

and 15-30 cm soil depths. Iprodione and its degradates were not detected below the 30 em

depth. RP30228 was a maximum average of 0.47 ppm at 28 days after treatment, declining only

to 0.15 ppm at 538 days. RP32490 was observed at relatively low concentrations (SO.09 ppm) in

the field. The observed DTso for iprodione and its degradates was 28 days in the top 15 em.

In the NC study, iprodione was applied 8 times to carrots at 1 lb ailA/application. The

observed DTso was <3 days at 0-15 em (loamy sand soil, pH 6.2 - 6.8). RP30228 and RP32490

were detected only at the 0-15 em depth. No residues were detected below 15 ern. The

concentrations of RP30228 were lower than those observed in CA, ranging from 0.01 to 0.08

ppm until 492 days. The observed DTso for iprodione and its degradates was also <3 days.

Aquatic Field Dissipation

In aquatic field dissipation studies (MRID 43718301), iprodione was applied twice to

flooded rice paddies at 0.5 lblacre at 15-day intervals at two sites (TX and MS). Iprodione was

applied to the rice foliage at both sites (55% canopy coverage at TX, 85% at MS). The two sites

were flooded for 1 month. Flood water dissipation half-lives for iprodione were 3.7 days in TX

and 2.9 days in MS; soil half-lives were 4.1 and 3.4 months in MS and TX, respectively.

Maximum concentrations observed in paddy water in both studies were around 500 ug/L,

Storage sample recoveries for 3,5-DCA were only 18%; thus, this study is not suitable for

characterizing the formation or persistence of 3,5-DCA. The major degradates observed at both

sites were RP30228 and RP37176. Water and soil dissipation half-lives for the TTR were not

significantly different from those ofthe parent only.

8
Volatilization/Long-Range Transport

Iprodione is not volatile, as indicated by the calculated Henry's Law constant of 2.7 x 10-

9 atm m3/mol, so long-range transport is not expected to occur. The Agency has not received any

direct measurements of volatility for 3,5-DCA, RP30228, RP35606, or RP32490. In the absence

of such data, the Agency used EPISuite to estimate Henry's Law constants for these chemicals.

For 3,5-DCA, the estimated Henry's Law constant is much higher than that of parent iprodione

(around 10-6 atm-mvrnol), while for the other degradates estimated Henry's Law constants are

much lower than for the parent (less than 10-12 atrn-rrr'zmol), Although 3,5-DCA is expected to

be more volatile than the parent or the other degradates based on estimated data, it was not

detected in the volatile traps in the submitted laboratory studies.

Fate Properties of Degradates

3,5-DCA

Results of batch sorption tests (MRID 45114101) on five soils are summarized in Table

4. Isotherms of 3,5-DCA for these five soils are nonlinear, with Freundlich exponents around

0.7. This means that sorption affinity decreases as concentrations increase, and that 3,5-DCA

will become less mobile as concentrations decrease. Based on the FAO soil mobility

classification scheme used by EFED, this chemical is classified as moderately mobile, with an

average Kocof 664 mIlgoc.

An aerobic soil metabolism study of 3,5-DCA on two different soils showed little

evidence that 3,5-DCA appreciably degraded over a 9-month period at 25°C (MRID 45239201).

Apparent dissipation was caused by a high level of unextracted residues. Unextracted residues

accounted for 66% and 81% of the applied in the two systems. The only residues that were

distinguishable from the applied 3,5-DCA amounted to only 4 to 5% ofthe applied 14C.

In order to address the issue of unextracted residues, Bayer Cropscience conducted a

second study that was submitted in 2010 which used more aggressive analytical methods to

extract 3,5-DCA from the soil (MRID 48219201). Based on nonlinear regression analysis,

estimated half-lives ranged from 40 to 107 days in silt loam and sand soils. Unextractable

residues were still high, and averaged 54.4-67.8% of the applied at 119 days posttreatment;

however, based on an EPA review of the analytical method, in which Bayer Cropscience

employed sufficiently exhaustive methods to extract 3,5-DCA, it was determined that the 3,5-

DCA residues were bound to the soil and assumed unavailable for off-site transport.

RP30228, RP35606, and RP32490

The degradates RP30228, RP35606, and RP32490 have been newly identified as residues

of concern and as such registrant-submitted fate data are not available. Using the structural

analysis tools in EPISuite, physical-chemical properties and fate parameters were estimated for

the three degradates (Table 5). The degradates appear to be similar in solubility and

octanollwater partition coefficients as parent iprodione, but more mobile, based on their

estimated Kocvalues.

9
D d t f EPIS it MOl dO able 50 Estimated Fate Properties or ajor IIrro ione egra a es rom me

Property RP30228 RP32490 RP35606

Molecular formula C13H13ClzN303 CloH7C12N303 C13HlsC12N304

Molecular weight (g/mole) 330.2 288 348

Vapor pressure (Torr, 25°C) 1.12x 1O.11 6.4x1O'11 3.7x1O'lL

Henry's Law Constant 3.5x1O'13 3.0x1O'14 2.2xlO· 13

(atm m3/mol)

OctanoliWater Coefficient 3.24 1.48 3.41

(Log Kow)

Solubility in water (mg/L, 25°C) 13.9 792 7.8

Organic carbon partitioning coefficient (Koc)(mL/goc)1 53 - 424 16 - 47 21 - 90 ..

T

1. Values represent range Koc estimates denved usmg the Molecular Connectivity Index (MCI) method and the

log Kowmethod, both available in EPISuite.

Monitoring

A detailed discussion of the monitoring results for iprodione and 3,5-DCA is provided in

the previous drinking water assessment (D385307+, April 5, 2011). A summary of the results is

provided in Table 6. While the concentrations, for the most part, are lower than 1 ug/L for

iprodione and 3,5-DCA, there is uncertainty in these numbers because the detection limits were

as high as 5 giL for iprodione and 10 giL for 3,5-DCA. No monitoring data specifically for

RP30228, RP35606, or RP32490 were available.

Tabl 6 M e 0 onitortng Daat Summary f,or ItprodOtone and35, -DCA

Concentration Frequency Limit of

Location Range Detection Date Source

(lt2!L) of Detects (lt2/L)

Iprodione, Surface Water

National 0.01-45.3 120/4,715 0.01-1.9 2000-2010 NAWQA

CA -- 0/11 NA 2004/2005 CDPR

Rahway, NJ 0.051 - 0.564 34/498 0.05 2006 -2009 MRID 47881501

Bradenton, FL -- 0/165 0.05 2006 -2009 MRID 47881501

Aurora, IL -- 0/169 0.05 2006 -2009 MRID 47881501

Iprodione, Groundwater

National 0.016 1/3029 0.01-1.4 2000-2010 NAWQA

Suffolk County 5.75 1 1 12,379* 0.2 - 5 1998 - 2010 Suffolk County

3,5-DCA, Surface Water

National 0.002 - 0.09 77 14,139 0.003 - 0.05 2000 -2010 NAWQA

Rahway, NJ 0.027 1/498 0.05 2006 - 2009 MRID 47881501

Bradenton, FL -- 0/165 0.05 2006 - 2009 MRID 47881501

Aurora, IL -- 0/169 0.05 2006 - 2009 MRID 47881501

3,5-DCA, Groundwater

National 0.001 - 0.1 27/2,772 0.003-0.013 2000-2010 NAWQA

Suffolk County -- 0/1583* 0.3 - 10 1998 - 2010 Suffolk County

NA - not available

* 56 of the iprodione samples and 11 ofthe 3,5-DCA samples had reporting limits greater than 1 ug/L. Suffolk

County indicated that the single detection was actually from an irrigation well which does not serve as a drinking

water source and should not have been captured in the database of groundwater drinking water sources.

10
Drinking Water Exposure Modeling

EDWCs were generated using EFED's standard suite of models. The Pesticide Root

Zone Model (PRZM, v3.12.2, May 2005) and Exposure Analysis Modeling System (EXAMS,

v2.98.4.6, April 2005) are simulation models coupled with the input shell PE5.pl (v.5, Nov. 15,

2006) to generate EDWCs of iprodione TTR and 3,5-DCA residues that may occur in surface

water used as drinking water. The PRZM model simulates runoff from and transformation of

pesticide within a standard watershed consisting of a 172.8 ha field of treated crops. The

EXAMS model simulates associated aquatic concentrations (from runoff, erosion, and spray drift

of pesticide) within an adjacent standard drinking water "index" reservoir of 5.26 ha surface

area, and average depth 2.74 m. A more detailed description of the index reservoir and its

watershed can be found in Jones et al., 1998. The coupled PRZM and EXAMS models and users

manuals may be downloaded from the U.S. Environmental Protection Agency (EPA) Water

Models web-page (http://www.epa.gov/oppefedl/models/water/). Percent Cropped Area (PCA)

adjustment factors that account for the maximum area within a watershed that may be planted

with the modeled crop are applied to concentrations predicted by PRZM/EXAMS.

Screening Concentration in Ground Water (SCI-GROW v2.3, Jul. 29, 2003) is a

regression model used as a screening tool to estimate pesticide concentrations found in ground

water used as drinking water. SCI-GROW was developed by fitting a linear model to ground

water concentrations with the Relative Index of Leaching Potential (RILP) as the independent

variable. Ground water concentrations were taken from 90-day average high concentrations

from Prospective Ground Water studies. The RILP is a function of aerobic soil metabolism and

the soil-water partition coefficient. The output of SCI-GROW represents the concentrations of

iprodione TTR and 3,5-DCA residue that might be expected in shallow unconfined aquifers

under sandy soils, which is representative of the ground water most vulnerable to pesticide

contamination and likely to serve as a drinking water source. The SCI-GROW model and user's

manual may also be downloaded from the EPA Water Models web-page (USEPA, 2006).

The EFED Tier 1 Rice Model (v1.0, May 8, 2007b) was used to estimate aquatic

exposures for direct water use with conservative, maximum values that represent high exposure

sites for rice use. Each of these sites represents a water body holding a 10 em water depth.

When a pesticide is applied to a water body, the model assumes that it will instantaneously

partition between a water phase and a sediment phase based on the partition coefficient of the

chemical. The formula ofthe Tier I Rice Model vl.O is as follows:

11
c - mat'

w - 0.00105 + 0.00013Kd

and, if appropriate:

where:

Cw = water concentration [ug/L]

m.,' = mass applied per unit area [kg/ha]

K, = water-sediment partitioning coefficient [Llkg]

Koc = organic carbon partitioning coefficient [Llkg]

Drinking water concentrations were determined for iprodione TTR and degradate 3,5-

DCA. Calculation of iprodione TTR concentrations is described in the first section below, and

calculation of 3,5-DCA concentrations are described in a subsequent section.

Drinking Water Estimates for Parent Iprodione

Methodsfor Determining Parent (Iprodione) Concentrations

Iprodione TTR EDWCs were determined for the iprodione uses listed in Table 7. For the

rice use, surface water concentrations were determined using the Tier I Rice Model. For

groundwater concentrations, SCIGROW 2.3 was used.

Input parameters for PRZMlEXAMS iprodione TTR are given in Tables 7 and 8. Input

parameters for the Tier I Rice Model are given in Table 9. Input parameters for SCIGROW are

given in Table 10. Parameter selections were determined according to EFED guidance

(USEPA, 2009) unless otherwise specified. As applications to turf are permitted under the

current labels, no percent cropped area adjustment factors were applied to the results, per current

EFED guidance (USEPA, 2010). Although EPISuite estimates for the iprodione degradates

indicate they are more mobile than the parent, the Koc for iprodione was used in the TTR

modeling as it is based on study data and not model predictions.

In the previous assessment (D385307+, April 5, 2011), EFED conservatively assumed

100% ofthe iprodione was converted to 3,5-DCA. In the current refinement, EFED has used the

findings from the aerobic soil metabolism study (MRID 43091002) to estimate that 75% of

applied iprodione is converted to 3,5-DCA, and the remaining 25% of applied remains as

iprodione TTR on the field, available for transport in runoff. Actual conversion percentages

must lie between the extremes of 0 and 100% conversion of iprodione to 3,5-DCA. EFED

believes that the assumption of 75% conversion is a realistic refinement based on the limited

aerobic soil metabolism data. After modeling iprodione using the application rates shown in

Table 7, the results were postprocessed by applying a scaling factor of 0.25.

For the PRZM/EXAMS simulations, application dates that are given in Table 7 are the

ones that were chosen with consideration for the label recommendations for application timing

12
and pre-harvest interval, along with the crop dates associated with each PRZM scenario file. The

application dates used in these simulations were selected from the approximate middle of the

possible window of applications; however, the selection of the date is not a precise process, and

there may be some variability about the date selection. Application dates for currently labeled

uses are the same as those used in EFED's previous drinking water assessment (USEPA, 2007a).

T hi 7 U a e , se-speci IC scenarios an usage mpu d ts £or iprod'tone TTR sur ace f water moder109

Iprodione

Use Application EFED Scenario Application Number of Date of Application

method Rate applications (interval)

[lb, a.i.lAI

]

almond/pistachio ground CA Almond 0.52 4 Feb7, 14,28, Mar7

spray

almond/pistachio aerial spray CA Almond 0.52 4 Feb7, 14,28, Mar7

bean aerial spray MI Beans 1.53 2 Jun 1,6

bean aerial spray OR Beans 1.53 2 May 5,10

berries ground OR Berries 1 4 May 20, Jun 3, 17,

spray lull

broccoli ground CA Cole crop 1.5 2 Jan 15, 184

spray

carrot aerial spray FL Carrot 1 4 Sep 25, Oct 6, 27,

Nov 27

carrot aerial spray FL Carrot I 4 Nov 20,27, Dec

3,10

Oct 9, 16,23,30,

carrot aerial spray FL Carrot 0.5 10 Nov 6, 13,20,27,

Dec 4,11

chinese mustard ground FL cabbage 0.5 4 Nov 20,30, Dec 10,

spray 20

cotton in furrow CA Cotton 0.27 1 MayS

cotton in furrow MS Cotton 0.27 1 May 1

cotton in furrow NC Cotton 0.27 1 Jun 1

cucurbits' ground FL cucumber 29 2 Oct 6, 23 incorporate

cucurbits" ground FL cucumber 1 3 Oct 6, 23, Nov 4 incorporate

cucurbits" ground CAmelon 29 2 May 6, 23 incorporate

cucurbits ground CA melon 1 3 May 6, 23, Jun 4 incorporate

fruiting ground CA tomato 3 1 Feb 19 vegetables" incorporate

fruiting ground CA tomato 29 2 Feb 19, Mar 8 vegetables" incorporate

fruiting ground CA tomato 1 3 Feb 19,Mar8,20 vezetables" incorporate

fruiting ground FL peppers 3 1 Augn vegetables" incorporate

fruiting ground FL peppers 29 2 Augn, Sep 8 vegetables" incorporate

fruiting ground FL peppers 1 3 Aug 22, Sep 8, 20 vegetables" incorporate

13
Iprodione

Use Application EFED Scenario Application Number of Date of Application

method Rate applications (interval)

rib. a.i.lA1J

fruiting ground FL tomato 3 1 Jan 22 vegetables" incorporate

fruiting ground FL tomato 29 2 Jan 22, Feb 8 vegetables" incorporate

fruiting ground FLtomato 1 3 Jan 22, Feb 8, 20 vegetables" incorporate

fruiting ground PA tomato 3 1 Apr 6 vegetables" incorporate

fruiting ground PA tomato 29 2 Apr 6, 23 vegetables" incorporate

fruiting ground PA tomato 1 3 Apr 6, 23, May 5 vegetables" incorporate

garlic in furrow CA garlic 2 1 Sep 17

g!apes ground NY Grapes 1 4 Jun 20, 30, JulIO,

spray 20

grapes ground CA Grapes 1 4 May 1,11,21,31 spray

aerial

lettuce /ground CA lettuce 1 3 Feb 20, Mar 2, 12

spray

lettuce ground CA lettuce 1 3 Feb 20, Mar 2, 12 spray

onion aerial spray GAonion 0.75 5 Mar 1, 11, 21, 31,

Apr 10

onion aerial spray CA onion 0.75 5 Jan 10,20,30, Feb

9,19

Mar 1, 8,15,22,29,

onion aerial spray GA onion 0.5 10 Apr 5, 12, 19,26,

May 3

Feb 18,25, Mar 4,

onion aerial spray CA onion 0.5 10 11, 18,25, Apr 1, 8,

15,22

ornamentals ground CA 1.25 4 Jull, 8,15,22 spray Impervious/residential

peanut in furrow NC peanut 1.5 2 May 2, Jun 1

peanut ground NC peanut 1.5 2 May 7, Jun 1 spray

peanut ground NC peanut 1.5 2 May 17, Jun 1 spray

peanut ground NC peanut 1.5 2 Jun 1,15 spray

potato aerial spray Me Potatoes 1 4 Jull, 8, 15,22

rice Not Tier 1 Rice Model 0.5 2 Not applicable applicable

stone fruits aerial GA Peaches 1 28 Mar 1,8,15,22

stone fruits aerial MI Cherries 1 28 Apr 25 Mayl,8,15

strawberry aerial spray FL Strawberry 0.5 10 May 1,8,15,22, Jun

11,18, 25,Jul 2,22,29

strawberry aerial spray FL Strawberry 1.0 110 May 1

14
Iprodione

Use Application EFED Scenario Application Number of Date of Application

method Rate applications (interval)

fib. a.i.lAIl

turf(golf courses, ground Jull, 15,29, Aug sod farms, PA turf 4 6

ornamental turf) spray 12,26, Sep 9

turf (golf courses, ground Jull, 15,29, Aug sod farms, FL Turf 4 6

ornamental turf) spray 12,26, Sep 9

turf(golf courses, ground sod farms, PA turf 1.25 4 Jull, 8,15,22

ornamental turf) spray

turf (golf courses, ground sod farms, FL Turf 1.25 4 Jull, 8,15,22

ornamental turf) spray

1. Application rates were multiplied by 1.12 to convert to kg aifha for use m modelmg.

2. Previous assessment used 1.0 lbs ai./A. Current labels reflect 0.5 lbs ai/A.

3. Previous assessment used l Ib ai/A. Current label (Reg. no. 264-689,2/27/2009) reflects 1.5 lbs ai/A.

4. First application at 2-4 leafstage, assumed to occur 2 weeks after emergence. No retreatment interval

specified; assumed 3 days.

5. First application incorporated to a depth of3 inches. Subsequent applications occur via drip irrigation at

surface. Max annual application = 3 lbs aifyr.

6. First application incorporated to a depth of 3 inches. Subsequent applications occur via drip irrigation at

surface. Max annual application = 3 lbs ai/yr.

7. First application can be aerial, but subsequent applications are restricted to ground applications by label.

8. Previous assessment used 4 applications/yr. Current labels reflect 2 applications/yr.

9. First application at 2 lbs aifA, second application at 1 Ib ai/A.

10. Previous assessment used 4 applications/yr. Current labels reflect 1 application/yr.

T bl 8 PRZM / EXAMS a e ° InputparaEneters ° or rpro ione dO TTR

PARAMETER (units) VALUE SOURCE COMMENT

Application Rate (kg see Table 7 Label See Table 7

a.i./ha)

Number ofApplications see Table 7 Label

Interval between see Table 7 Label

Applications

Molecular weight 330.2 g/mol Iprodione RED, 1998 -

Henry's Law Constant 2.7 x 1O-9atm-m3/mol Iprodione RED, 1998 calculated value

Vapor Pressure 2.7 x 10-7 Torr Iprodione RED, 1998 -

Solubility in Water @ 13 mg/L Iprodione RED, 1998 -

20°C, pH 8

Soil Partition Coefficient 426 ml/goc MRID: 43349202 Mean of 4 soils for iprodione

K oc

CAM (Chemical 2

Application Method)

15
PARAMETER (units) VALUE SOURCE COMMENT

Depth ofIncorporation 4cm Iprodione label. A default of 4 em was used,

unless label specified differently

Application efficiency

Ground spray: 0.99 Input Guidance. Aerial spray: 0.95

Spray drift fraction Ground spray: 0.064 Input Guidance.

Aerial spray: 0.16

Application date various Labels See Table 6

(day/month)

Hydrolysis Half-life (days) 772 (pH 5) MRID: 41885401 266 (pH 7)

56 (pH 9)

Anaerobic Aquatic 276 MRID: 43091002; 3 x anaerobic aquatic

Metabolism Half-life 44590501 metabolism half-life

(days)

Aerobic Soil Metabolism 57.5 MRIDs: 43091002 3 x aerobic soil metabolism

Half-life (days) half-life

Aqueous Photolysis Half- 64 MRID: 41861901

life (days) @ pH 7

Aerobic Aquatic 182 MRID: 41927601; 3 x aerobic aquatic metabolism

Metabolism Half-life 42503801 half-life

(days)

T bl 9 Ri a e ce mo edl"input parameters or rprod"tone TTR

Input Parameter Value Source Comment

Annual Application Rate 1.0 Ib a.i./A Label Two applications (@ 0.5 Ib ai/A)

allowed on label at 14-day intervals

by aerial spray

Soil Organic Carbon 426 mL/goc MRID: 43349202 Mean of 4 soils for iprodione

Partitioning Coefficient (Koc )

T bl 10 SCI a e " -GROW (v23) " mpu " t parame er va ues or t I I)JrOd"ione TTR

Input Parameter Value Source Comment

Maximum Yearly Application 24 Label. 6 x 4 lbs ailA for turf

Rate (lb a.i./A) 3 3 x 1 lbs ailA for fruiting vegetables,

cucurbits

Organic Carbon Partition 469 ml/goc MRID: Median Koc for iprodione

Coefficient (Koc) 43349202

Aerobic Soil Metabolism Half- 19.2 days MRID: Half-life estimated from single study

life 43091002

Results: Surface Water Concentrations ofIprodione TTR

Output from the surface water modeling of iprodione total toxic residues using

PRZM/EXAMS and accounting for the 75% instantaneous conversion of applied iprodione to

3,5-DCA is given in Table 11. The highest concentrations (excluding rice use) are from the turf

16
use (PA turf scenario), and this is due to a large extent to the high label application rate for turf

(24 lb ailA/yr). The Pennsylvania turf use results in EDWCs of 92 ug/l, for acute, 31 IlgIL for

chronic, and 18 ug/L for cancer. These values represent the one-in-ten-year peak concentration,

the one-in-ten-year annual mean concentration, and the 30-year mean concentration,

respectively. Acute concentrations from all of the modeled crops (excluding rice) fall in the

range of 0.0063 to 92 ug/L; chronic concentrations are in the range of 0.0025 to 31 ug/L; and

cancer concentrations are in the range of 0.00075 to 18 ug/L. Modeling scenarios that result in

particularly high peak surface water concentrations include Pennsylvania turf, Florida turf,

Florida carrots, Florida cucumbers, California cole crops, Florida peppers, Georgia onions, North

Carolina peanuts, and Florida strawberries.

For iprodione use on rice, the Tier I Rice Model gives a concentration (acute and chronic)

of 175 ug/L, which is the highest surface water concentration associated with any use (see Table

11). The Tier I Rice Model estimates concentrations from an assumed equilibration of the

pesticide with hypothetical quantities of water and sediment, and without any degradation of the

pesticide. This model is intended to serve only as a screen, and if concerns are raised by the

output of this model, further refinements should be considered. Maximum concentrations of

iprodione measured in two aquatic field dissipation studies conducted on rice in MS and TX

were approximately 500 ug/L, where measurements were taken within the paddy.

Concentrations in downstream receiving water would be expected to be lower than 500 ug/L,

due to dilution.

Table 11. Iprodione TTR Tier II EDWCs for surface water, assuming 75% conversion to

3,5-DCA

Application I-in-IO I-in-IO 30- year

Use Application EFED Scenario Rate Number of year year average

method [lb. a.i.lA] applications acute chronic (1Lg!L)

(Jlg/L) (Jl2!L)

almond! ground spray CAAlmond 0.5 4 5.5 1.7 0.93 pistachio

almond/ aerial spray CAAlmond 0.5 4 7.3 2.3 1.5 pistachio

bean aerial spray MI Beans 1.5 2 16 5.5 4

bean aerial spray OR Beans 1.5 2 13 3 2

berries ground spray OR Berries I o

4 4.5 1.95 1.45

broccoli ground spray CA Cole crop 1.5 2 29 9.25 5.75

carrot aerial spray FL Carrot 1 4 40 6 4

carrot aerial spray FL Carrot 0.5 10 46 7.5 4.25

chinese ground spray FL cabbage 0.5 4 12 2.13 1.28 mustard

cotton in furrow CA Cotton 0.27 1 0.0063 0.0025 0.00075

cotton in furrow MS Cotton 0.27 I 0.48 0.078 0.035

cotton in furrow NC Cotton 0.27 I 0.35 0.073 0.Q38

cucurbits ground FL cucumber 2 2 22 2.8 1.6 incorporate

cucurbits ground FL cucumber 1 3 36 3.5 1.7 incorporate

17
Application I-in-lO I-in-IO 30- year

Use Application EFED Scenario Rate Number of year year average

method [lb. a.i.lA] applications acute chronic (f.1glL)

(/.lglL) (/.lglL)

cucurbits ground CAmelon 2 2 0.8 0.21 0.073 incorporate

cucurbits ground CAmelon 1 3 0.73 0.1875 0.0675 incorporate

fruiting ground CA tomato 3 1 3.8 1.4 0.5 vegetables incorporate

fruiting ground CA tomato 2 2 5.3 1.9 0.6 vegetables incorporate

fruiting ground CA tomato 1 3 3.8 1.4 0.63 vegetables incorporate

fruiting ground FL peppers 3 1 13 1.6 0.73 vegetables incorporate

fruiting ground FL peppers 2 2 17 2.1 1.4 vegetables incorporate

fruiting ground FL peppers 1 3 25 3.3 2.2 vegetables incorporate

fruiting ground FL tomato 3 1 6 0.85 0.43 vegetables incorporate

fruiting ground FL tomato 2 2 11 1.6 0.78 vegetables incorporate

fruiting ground FL tomato 1 3 15 2.2 1.2 vegetables incorporate

fruiting ground PA tomato 3 1 3.0 0.80 0.45 vegetables incorporate

fruiting ground PA tomato 2 2 4.8 1.3 0.78 vegetables incorporate

fruiting ground PA tomato 1 3 8.8 2.3 1.3 vegetables incorporate

garlic in furrow CA garlic 2 I 0.45 0.13 0.05

grapes ground spray NY Grapes 1 4 18 7.8 5.3

grapes ground spray CA Grapes 1 4 3.5 1.8 1.5

aerial

lettuce /ground CA lettuce 1 3 21 7.3 4.0

spray

lettuce ground spray CA lettuce 1 3 20 7.0 3.8

onion aerial spray GA onion 0.75 5 18 4.0 2.5

onion aerial spray CAonion 0.75 5 11 4.5 3.3

onion aerial spray GAonion 0.5 10 26 5.5 3.8

omon aerial spray CA onion 0.5 10 8.8 4.0 3.5

ornamental ground spray

CA Impervious/ 1.25 4 0.75 0.30 0.23 residential

peanut in furrow NC peanut 1.5 2 2.2 0.65 0.4

peanut, ground spray NC peanut 1 3 13 3.5 2.4 cracking

peanut,

post- ground spray NC peanut 1 3 18 4.3 2.4

emergence

18
Application l-in-IO l-in-IO 30- year

Use Application EFED Scenario Rate Number of year year average

method [lb. a.i./A] applications acute chronic (Ilg/L)

(U1!/L) (u1!/L)

peanut, ground spray NC peanut 1 3 19 5.0 2.5 pegging

peanut, ground spray NC peanut 1.5 2 14 3.3 2.4 cracking

peanut,

post- ground spray NC peanut 1.5 2 15 3.5 2.3

emergence

peanut, ground spray NC peanut 1.5 2 23 5.5 2.5 pegging

potato aerial spray Me Potatoes 1 4 19 7.5 5.3

rice Not Tier I Rice 0.5 2 175 < 175 applicable Model < 175

stone fruits aerial GA Peaches 1 2 5.5 1.6 1.3

stone fruits aerial MI Cherries 1 2 6.5 2.5 2.0

strawberry aerial spray FL Strawberry 0.5 10 44 11 8.5

strawberry aerial spray FL Strawberry 1.0 1 18 2.5 1.6

turf ground spray PA turf 4 6 92 31 18

turf ground spray FL Turf 4 6 52 18 12

turf ground spray PA turf 1.25 4 14 6.0 3.5

turf ground spray FL Turf 1.25 4 7.3 2.4 1.9

Results: Groundwater Concentrations ofIprodione TTR

SCI-GROW was used to estimate groundwater concentrations resulting from the use of

iprodione. SCI-GROW is based on the median Koc (469 mLigoc) and aerobic soil metabolism

half-life (19.2 days) of the pesticide, the application rate, and the concentration data from 13

small-scale groundwater monitoring studies. For the highest application rate (turf, 6 x 4 lb

ai/acre), the groundwater concentration of total toxic residues is 1.17 )J.g/L. For the proposed

new uses on fruiting vegetables and cucurbits and the label amendment for peanuts (3 x 1 lb

ai/acre), the groundwater concentration of TTR is 0.15 ug/L. If it is assumed that 75% of

applied iprodione becomes 3,5-DCA, the groundwater concentrations of TTR for turf and new

uses become 0.29 ug/l, and 0.04 ,..,gIL, respectively.

Drinking Water Estimates for the Degradate 3,5-DCA

Methodsfor Determining 3,5-DCA Concentrations

Based on fate data that the registrant has submitted that characterize iprodione

degradation in water and soil, 3,5-DCA is formed in each metabolic study. Therefore, it is

reasonable to assume that 3,5-DCA can be simulated with the same scenarios as iprodione and

with the same molar application rate as iprodione. The same scenarios that were run for

iprodione (Table 7) were also run for 3,5-DCA. Application rates for these scenarios are the

same as for the equivalent iprodione applications, except that they were adjusted by the

molecular weight ratio (162/330), and by an assumed 75% conversion of iprodione to 3,5-DCA.

19
Chemical input parameters for 3,5-DCA are summarized in Table 12 for surface water, Table 13

for rice, and Table 14 for groundwater.

As supported by registrant-submitted information, the fundamental assumption employed

in this modeling is that a maximum of 75% of iprodione degrades to 3,5-DCA. Transformation

to 3,5-DCA is assumed to be rapid, based on the registrant studies. In the submitted studies, the

maximum formation of 3,5-DCA occurred approximately 30 days after the application of

iprodione. Additionally, uncharacterized, unextractable residues in aerobic soil studies formed at

levels greater than 10% between Day 14 and 30. As 3,5-DCA has been determined to form

unextractable residues (MRID 48219201) in aerobic soils, EFED has assumed that the

unextractable residues in the iprodione studies would most likely be 3,5-DCA. The assumed

rapid formation of 3,5-DCA from iprodione promotes high acute concentrations because of the

immediate availability of 75% of applied parent as 3,5-DCA. This is conservative in that slower

formation would result in lower peak concentrations, though not necessarily lower long-term

average concentrations. The application dates for 3,5-DCA were adjusted from those of

iprodione TTR by 14 days to account for delay in formation. Results, using application rates

adjusted for molecular weight, were postprocessed to account for the 75% conversion.

Ta e bl 12.PRZM / EXAMS'mpu paramett ers or 35, -DCA

PARAMETER (units) VALUE SOURCE COMMENT

Application Rate (kg a.i./ha) various (rate for Label See Table 7, above!

iprodione adjusted by

molecular weight

ratio)

Number of Applications various Label

Interval between various Label

Applications

Molecular weight 160 g/mol Iprodione RED, 1998 -

Henry's Law Constant 10'6 atm-mvrnol EPI Suite -

Vapor Pressure (torr) 2.7 x 10'9 EPI Suite -

Solubility in Water @ 20°C, 784 mg/L EPI Suite -

pH=8

Soil Organic Carbon 664 ml/g MRID: 43349202 Mean value

Partition Coefficient (Koc)

CAM (Chemical Application 2 Input Guidance.

Method)

Depth of Incorporation 4cm Iprodione label. A default of 4 em was used,

unless label specified differently

Application efficiency Ground spray: 0.99 Input Guidance.

Aerial spray: 0.95

Spray drift fraction Ground spray: 0.064 Input Guidance.

20
3,5,DCA application rate - iprodione application rate adjusted by molecular weight ratio (162/330 - 0.49)

PARAMETER (units) VALUE SOURCE COMMENT

Aerial spray: 0.16

Application date various Labels See Table 6

Hydrolysis Half-life Assumed Stable No data 3,5-DCA assumed stable

Aqueous Photolysis Half-life Assumed Stable No data 3,5-DCA assumed stable

@pH7

Aerobic Aquatic Metabolism 129 No data 2 x aerobic soil metabolism

Half-life value

Anaerobic Aquatic Assumed Stable No data 3,5-DCA assumed stable

Metabolism Half-life

Aerobic Soil Metabolism 64.5 MRIDs: 43091002, 95% DCL around mean value

Half-life 45239201,48219201 from seven values

I

T bl 13 a e . T"rer I Rice M d0 eI .mpu paramett ers or 35. -DCA

Input Parameter Value Source Comment

3,5-DCA application rate =

Annual Application Rate 0.49Ib./A Label iprodione application rate adjusted

by molecular weight ratio (162/330

= 0.49)

Soil Organic Carbon 662 mIlg MRID: 43349202 Mean of 4 soils Partitioning Coefficient (Koc )

T bl 14 SCI a e . -GROW (v.23)·mpu paramett er va ues I or 35, -DCA

Input Parameter Value Source Comment

3,5-DCA application rate =

Maximum Application Rate (lb Turf: 1.96 Label iprodione application rate

a.i./A) adjusted by molecular weight

ratio (162/330 = 0.49)

These represent highest and

Number of Applications per Year Turf: 6 Label lowest annual applications (see

Table 6, above)

Organic Carbon Partition 626 mIlg MRID: 45114101 Median Koc Coefficient (Koc)

Aerobic Soil Metabolism Half-life 49 days MRIDs 45239201, Median aerobic soil metabolism

48219201,43091002 half-life

Results: Surface Water Concentration ofDegradate 3,5-DCA

Results for surface water concentrations of 3,5-DCA are given in Table 15 for

PRZM/EXAMS surface water simulations. As with the TTR, the highest concentrations

(excluding rice) resulted from the Pennsylvania turf scenario, with an acute concentration of 115

ug/L, a chronic concentration of 42 ug/L, and a cancer concentration of 27 .uglL. For

groundwater, the EDWC was 0.81 ug/L for the turf application and 0.1 for the proposed new

uses (fruiting vegetables and cucurbits) and label amendments to peanuts.

21
Table 1 . 5 Summary 0 f surface water simu a Ions I f resu mgm. hiIgJh35DCA , - concentrations

l-in- l-in-l0 30-

Application Application Number of 10 year year

Use method EFED Scenario Rate applications year chronic average

[lb. a.i./A] acute (JiglL) (ug/L)

(Jig/L)

almond! ground spray CAAlmond 0.19 4 5.1 1.7 1.2 pistachio

almond! aerial spray CA Almond 0.19 4 7.8 2.6 2.1 pistachio

bean aerial spray MI Beans 0.56 2 21 8.5 6.0

bean aerial spray OR Beans 0.56 2 13 4.1 2.9

berries ground spray OR Berries 0.37 4 7.9 3.6 2.7

broccoli ground spray CA Cole crop 0.56 2 27 10 5.7

carrot aerial spray FL Carrot 0.37 4 46 8.9 5.0

carrot aerial spray FL Carrot 0.38 10 41 9.2 5.5

chinese ground spray FL cabbage 0.19 4 12 3.2 2.0 mustard

cotton in furrow CA Cotton 0.10 1 0.038 0.023 0.0075

cotton in furrow MS Cotton 0.10 1 0.58 0.098 0.045

cotton in furrow NC Cotton 0.10 1 0.31 0.083 0.060

cucurbits ground FL cucumber 0.74 2 0.25 0.16 0.060 incorporate

cucurbits ground FL cucumber 0.37 3 0.22 0.14 0.060 incorporate

cucurbits ground CAmelon 0.74 2 32 4.2 2.3 incorporate

cucurbits ground CAmelon 0.37 3 28 4.6 3.0 incorporate

fruiting ground CA tomato 1.10 1 1.9 0.65 0.34 vegetables incorporate

fruiting ground CA tomato 0.74 2 3.3 1.3 0.68 vegetables incorporate

fruiting ground CA tomato 0.37 3 5.4 1.8 0.83 vegetables incorporate

fruiting ground FL peppers 1.10 1 14 1.7 1.1 vegetables incorporate

fruiting ground FL peppers 0.74 2 28 4.1 2.6 vegetables incorporate

fruiting ground FL peppers 0.37 3 36 5.4 3.8 vegetables incorporate

fruiting ground FL tomato 1.10 1 9.0 1.4 0.65 vegetables incorporate

fruiting ground FL tomato 0.74 2 18 3.2 1.7 vegetables incorporate

fruiting ground FL tomato 0.37 3 28 4.9 2.7 vegetables incorporate

fruiting ground PA tomato 1.10 1 4.6 1.2 0.71 vegetables incorporate

fruiting ground PA tomato 0.74 2 8.0 2.9 1.8 vegetables incorporate

22
l-in- l-in-l0 30-

Application Application Number of 10 year year

Use method EFED Scenario Rate applications year chronic average

[lb. a.i.IA] acute (l1glL) (l1glL)

(ulZlL)

fruiting ground PA tomato 0.37 3 13 5.0 3.0 vegetables incorporate

garlic in furrow CA garlic 0.74 1 0.72 0.18 0.083

grapes ground spray NY Grapes 0.37 4 35 16 9.1

grapes ground spray CA Grapes 0.37 4 5.4 2.9 2.3

lettuce aerial/ground CA lettuce 0.37 3 20 7.6 5.1

spray

lettuce ground spray CA lettuce 0.37 3 20 6.8 3.8

onion aerial spray GA onion 0.28 5 33 6.3 4.1

onion aerial spray CA onion 0.28 5 13 5.2 4.3

onion aerial spray GA onion 0.19 10 43 10 6.2

omon aerial spray CA onion 0.19 10 13 6.0 5.4

ornamentals ground spray

CA Impervious/ 0.46 4 1.2 0.43 0.34 residential

peanut in furrow NC peanut 0.56 2 3.5 0.85 0.44

peanut, ground spray NCpeanut 0.38 3 25 6.7 3.9 cracking

peanut, ground spray NC peanut 0.38 3 25 6.7 3.8

postemergence

peanut, ground spray NC peanut 0.38 3 21 5.6 4.0 pegging

peanut, ground spray NC peanut 0.56 2 25 6.6 3.8 cracking

peanut, ground spray NC peanut 0.56 2 30 7.4 3.8

postemergence

peanut, ground spray NC peanut 0.56 2 24 6.0 4.0 pegging

potato aerial spray Me Potatoes 0.37 4 25 11 8.2

rice Not applicable Tier I Rice 0.19 2 211 <211 <211 Model

stone fruits aerial GA Peaches 0.37 2 9.8 2.6 2.0

stone fruits aerial MI Cherries 0.37 2 9.8 4.2 3.3

strawberry aerial spray FL Strawberry 0.19 10 63 16 13

strawberry aerial spray FL Strawberry 0.37 1 20 3.9 2.4

turf ground spray PA turf 1.47 6 115 42 27

turf ground spray FL Turf 1.47 6 80 25 17

turf ground spray PAturf 0.46 4 22 9.2 5.6

turf ground spray FL Turf 0.46 4 12 4.3 3.0

Drinking Water Treatment Effects

No specific information on the effects of drinking water treatment are available for

iprodione or its degradates 3,5-DCA, RP30228, RP35606, or RP32490. The EDWCs in this

assessment are representative of concentrations in drinking water source water (pre-treatment)

23
and are derived from daily instantaneous peak concentrations. For surface water, the conceptual

model assumes that a pesticide reaches surface water via spray drift and surface runoff. In the

water body the pesticide is assumed to be instantaneously completely-mixed. Iprodione TTR is

relatively stable to hydrolysis, and may therefore not degrade by hydrolysis during the time that

elapses from drinking water intake through distribution to the first tap. Because of its somewhat

low Koc values, treatment methods such as sedimentation and flocculation are not expected to be

effective at removing iprodione or its degradates. Iprodione also does not degrade due to

photolysis. If ultraviolet light were used as a means of disinfection, degradation of iprodione

would not be expected.

Uncertainties and Data Gaps

Prominent uncertainties include the characterization and quantification ofthe degradation

of iprodione and 3,5-DCA. Uncertainties also are associated with the formation of 3,5-DCA.

Degradation quantification was confounded by large amounts of unextracted material that were

reported in the degradation studies conducted with soil for both iprodione and 3,5-DCA. The

large amount of unextracted and uncharacterized material hinders accurate estimation of

degradation rates, but does tend to suggest that iprodione might degrade very slowly in soil.

However, aerobic soil metabolism studies on 3,5-DCA have demonstrated that it binds to soil as

unextractable residue (MRID 48219201). Acceptable aerobic soil metabolism data are only

available for iprodione on one soil. Current data requirements specify a total of four soils. If

additional soils were assessed with an analytical method that could minimize unextractable

residues, this source of uncertainty could be reduced.

As mentioned in the Environmental Fate section (p 6), the primary means for iprodione

degradation in aquatic systems appears to be via hydrolysis. In modeling EDWCs for the

iprodione TTR, degradation via hydrolysis and aerobic aquatic metabolism were incorporated

into the model runs. In both studies, the primary degrade ofiprodione at pH 9 was RP 30228. In

the hydrolysis study (MRID 41885401), maximum formation of RP30228 occurred in a very

quickly (93% at 107 minutes), while in the aerobic aquatic metabolism study (MRID

41927601/42503801) the maximum formation ofRP30228 occurred at a much slower rate (65%

at 14 days). As the rates observed in the hydrolysis study were faster for both the parent and the

TTR than the rates observed in the aerobic aquatic metabolism study, hydrolysis could be

affecting the degradation rates observed in the aerobic aquatic metabolism study and using both

degradation rates in the model could result in a "double counting" ofthe degradation, resulting in

an underprediction ofthe EDWCs.

There is uncertainty in EFED's assumption that 75% of the applied iprodione is

converted to 3,5-DCA. EFED has based this assumption on the levels of unextracted and

uncharacterized residues found in aerobic soil metabolism studies and that other studies indicate

that 3,5-DCA is the terminal degradate of iprodione and that it binds unextractably to soil.

However, because the unextractable residues from the irpdodione aerobic soil metabolism

studies were not characterized as being 3,5-DCA, the 75% conversion rate could be an

overestimate, resulting in overpredicted EDWCs from the models.

There is uncertainty associated with general model representativeness, as well as with the

selection ofinput parameters. In this regard, one ofthe potentially important parameters that can

24
impact concentration estimates is the selection of application dates. Although the pesticide

application dates were selected to be most appropriate according to the model user's best

judgment and with considerations for label restrictions and simulated cropping dates, uncertainty

nevertheless results because the application window (the time span during a season that a

pesticide may likely be applied) for a pesticide may be wide and actual application dates are

unknown. Such uncertainty is a function of temporal proximity of pesticide applications to rain

events.

The Tier II drinking water assessment relied on maximum use patterns. To the extent

that actual use patterns are less than the labeled maximums, actual environmental exposures

could be lower. Additionally, because iprodione can be used on turf, no adjustment was made to

account for percent cropped area. To the extent that the location-specific PCAs are less than

assumed in this assessment, actual environmental exposures could be lower.

While monitoring data for iprodione and 3,5-DCA indicated much lower levels of these

analytes in surface water or groundwater, other than the focused monitoring for golf courses and

plant nurseries conducted by Bayer Cropscience between 2006 to 2009, monitoring was not

targeted specifically at iprodione use areas or conducted during times of known iprodione use,

and as such may not reflect potential peak iprodione concentrations that may occur in surface

waters when runoff events occur shortly after application. Adding to this uncertainty, reporting

limits for some of the data have varied over the years. The Suffolk County Drinking Water

Database did not report trace levels (e.g., levels above the method detection limit but below the

reporting limit), which would have facilitated interpretation of their drinking water source

monitoring results. Lastly, great uncertainty surrounds levels of the iprodione TTR in the

environment, as monitoring data for the other three residues of concern (RP30228, RP35606, or

RP32490) are not available.

In the case of the targeted study conducted by Bayer (MRIDs 47579101 and 47881501),

annual iprodione sales data and acreages for golf courses and watersheds were provided. Based

on these data, annual use estimates, in pounds ai per acre, were developed for the golf courses

and the watersheds (Table 16). Compared to the modeled runs for turf (maximum annual usage

of 24 lbs ailA), while the annual amount used on the golf courses is lower, the data indicate that

annual use rates close to the 24 lbs ailA maximum have actually been observed, particularly in

the Rahway, NJ watershed. The surface water modeling for turf assumes a percent cropped area

adjustment factor of 1, which means the entire watershed is treated with iprodione. Taking the

acreage of the Rahway watershed into account, area-averaged annual application rates in this

watershed are as much as four orders of magnitude less than the 24 lbs ailA maximum used in

modeling. Ifthe results from the PRZM/EXAMS runs were scaled using the maximum average

watershed annual use rate (0.065 lbs ai/A watershed), the EDWCs would all be below 1 ug/L.

For 3,5-DCA, the same scaling would result in EDWCs below 0.5 ug/L. These scaled values are

more comparable to the results provided in Bayer's surface water monitoring study, which

reported concentrations ofiprodione and 3,5-DCA below 0.56 ug/L and 0.1 ug/L, respectively.

Table 16. Iprodione sales data during monitorina study, 2004-2008

Lbs ai/Total Acres I Bradenton, FL I Rahway, NJ* I

(n=12) (n=18)

Annual iprodione use per acre of golf course

25

Aurora,lL

(n=lll)
Average ± Std Dev

I

0.73 ± 0.43

I

6.56 ± 7.22

I 1.50 ± 1.89

(Min-Max) (0.12 - 1.36) (0.53 - 21.5) (0.13 - 14.7)

Annual iprodione use per acre of watershed

Average ± Std Dev I 0.002 I 0.065 I 0.002

(Min-Max) (0.001 - 0.004) (0.006 - 0.091) (0.001 - 0.002)

The estimates from the Tier I Rice Model are screening-level estimates and, as such, are

expected to generate high-end EECs that are likely to exceed peak concentrations of pesticides in

water bodies downstream ofrice paddies. Neither degradation ofthe pesticide nor mass transfer

from the aqueous phase to the sediment is considered in the model's conceptualization. The

absence of degradation adds conservatism to the model (i.e., estimated concentrations should be

higher than those usually found in rice paddies). The absence of mass transfer processes can

either add or reduce conservatism depending on various conditions such as whether the pesticide

is soil or water applied, and whether actual degradation occurs more rapidly in the sediment or

the water compartment.

Lastly, it should be noted that this assessment only examines the formation of 3,5-DCA

from the degradation of iprodione. 3,5-DCA is also formed during the degradation of the

fungicide vinclozalin. While annual use rates (Appendix 2), estimated by the USGS NAWQA

program, indicate the use of vinclozalin in 2002 was roughly 11% that of iprodione use (52,000

lbs versus 460,000 lbs), the data also indicate that both fungicides may be used in the same

watersheds. As such, EDWCs for 3,5-DCA may be underestimated to a degree that is not

known.

CONCLUSIONS

Revised EDWCs for iprodione and 3,5-DCA are presented in Tables 1 and 2. Acute

concentrations for iprodione from all of the modeled crops (excluding rice) fell in the range of

0.01 to 92 ug/L; chronic concentrations were in the range of 0.0 to 31 ug/L; and cancer

concentrations were in the range of 0.0 to 18 ug/L. Acute concentrations for 3,5-DCA from all

of the modeled crops (excluding rice) fell in the range of 0.04 to 115 ug/L; chronic

concentrations were in the range of 0.02 to 42 ug/L; and cancer concentrations were in the range

of 0.01 to 27 ug/L, Groundwater concentrations for the highest annual use of iprodione (24 lbs

ai/A) were 0.29 and 0.81 ug/L for iprodione and 3,5-DCA, respectively.

REFERENCES

California Department of Pesticide Regulation (CDPR) Surface Water Database. Searched

3/15/2011. http://cdpr.ca.gov/docs/emon/surfwtr/surfcont.htm

Jones, R. D., S. Abel, W. R. Effland, R. Matzner, R. Parker. 1998. An Index Reservoir for Use

in Assessing Drinking Water Exposure. Proposed Methods for Basin-scale Estimation of

Pesticide Concentrations in Flowing Water and Reservoirs for Tolerance Reassessment.

Presentation to FIFRA Science Advisory Panel, June 29-30, 1998. Online at:

http://v.ww.epa.gov/scipoly/sap/1998/index.htm

26
USEPA. 1998. Reregistration Eligibility Decision Iprodione. USEPAJOffice of Prevention,

Pesticides, and Toxic Substances. EPA738-R-98-019. November 1998

USEPA. 2002. SCIGROW: Users Manual. Online at:

http://\\'\\w.epa. gO\!oppefed 1imodels/\vater!#sci2.row

USEPA 2006. Memorandum: Standardized Soil Mobility Classification Guidance.

Environmental Fate and Effects Division. April 21, 2006.

USEPA 2007a. Iprodione drinking water assessment, including proposed new use on pistachio

(IR4) and label revisions affecting rates for strawberries, stone fruits, and grapes. D285550.

March 6, 2007.

USEPA. 2007b. Tier I Rice Model Manual. Online at:

USEPA. 2009. Guidance for Selecting Input Parameters in Modeling the Environmental Fate

and Transport of Pesticides. U.S. Environmental Protection Agency, Office of chemical Safety

and Pollution Prevention, Office of Pesticide Programs, Environmental Fate and Effects

Division, Oct. 22, 2009. Online at:

http://wvvw.epa.gov/oppefedl/models/water/inputparameterguidance.htm

USEPA. 2010. Development and Use of Percent Cropped Area Adjustment Factors in Drinking

Water Exposure Assessments. U.S. Environmental Protection Agency, Office of chemical Safety

and Pollution Prevention, Office ofPesticide Programs, Environmental Fate and Effects

Division, September 9, 2010. Online at:

http~!\v\vw.epa.goYioppefedl/models\\ater!pca adjustment dwa.html

USEPA. 2011. Memorandum: Iprodione drinking water assessment for label amendments and

proposed new uses on fruiting vegetables and cucurbits. Environmental Fate and Effects

Division. April 5, 2011. DP Barcode: D385307.

USEPA. 2011. Memorandum: Iprodione; Report ofthe Residues ofConcern Knowledgebase

Subcommittee (ROCKS). Health Effects Division. October 5,2011. DP Barcode: D393960.

USGS National Water Quality Assessment Data Warehouse (NAWQA). Searched 3/7/2011.

http://infotrek.er. usgs. gOYInawqa queries/swmaster/index. jsp

MRIDs

MRID: 41755801

Spare, W. (1990) Anaerobic Aquatic Metabolism ofIprodione: Lab Project Number: 1510.

Unpublished study prepared by Agrisearch Inc. 114 p.

27
MRID: 41861901

Adrian, P.; Robles, J. (1991) Carbon 14-Iprodione: Aqueous Photolysis: Lab Project Number:

90/22: AG/CBLD/AN/9115524. Unpub-lished study prepared by Rhone-Poulenc Secteur Agro.

97 p.

MRID: 41877401

Norris, F. (1991) A Terrestrial Field Soil Dissipation Study with Iprodione: Lab Project Number:

40644: EC/P-89-0013. Unpublished study prepared by Rhone-Poulenc Ag Co.; A & L Eastern

Agricultu- ral Labs, Inc.; Morse Labs., Inc. 275 p.

MRID: 41885401

Das, Y. (1990) Hydrolysis ofPhenyl(U)-carbon 14 Iprodione in Aqueous Solutions Buffered at

pH 5, 7 and 9: Lab Project Number: 89100. Unpublished study prepared by Innovative

Scientific Services, Inc. 96 p.

MRID: 41927601

Spare, W. (1991) Aerobic Aquatic Metabolism ofIprodione: Lab Pro- ject Number: 1514.

Unpublished study prepared by Agrisearch Inc. 147 p.

MRID: 42503801

Spare, W. (1992) Aerobic Aquaticc Metabolism ofIprodione: Supplemental Report MRID

419276011: Lab Project Number: 1514. Unpublished study prepared by Agrisearch Inc. 117 p.

MRID: 43091002

Waring, A. (1993) (carbon 14) Iprodione: Aerobic Soil Metabolism: Final Report: Lab Project

Number: 68/132: 68/132-1015. Unpublished study prepared by Hazleton Europe. 105 p.

MRID: 43349202

Burr, C.; Newby, S. (1994) Iprodione: Adsorption/Desorption to and from Four Soils and an

Aquatic Sediment: Lab Project Number: P94/014. Unpublished study prepared by RhonePoulenc Agriculture Ltd. 81 p.

MRID: 43718301

Chancey, E. (1995) An Aquatic Field Dissipation Study with Iprodione: Lab Project Number:

44729: EC-92-187: FAD-IPR-RI-MS-92. Unpublished study prepared by Rhone-Poulenc Ag

Co.; Agvise, Inc.; and South Texas Ag Research Inc. 374 p.

MRID: 44590501

Waring, A. (1993) (carbon 14) Iprodione: Soil Degradation: Final Report: Lab Project Number:

68/139-1015. Unpublished study prepared by Hazleton UK. 73 p.

MRID: 45114101

Feung, C. (1999) Iprodione Metabolite: (carbon-14)-3,5-Dichloroaniline Soil

Adsorption/Desorption Study: Lab Project Number: 99R16744. Unpublished study prepared by

Rhone Poulenc Ag Company. 165 p.

28
MRID: 45239201

Quarmy, D. (2000) Iprodione Metabolite: (carbon-14)-3,5-Dichloroaniline Aerobic Soil

Metabolism: Lab Project Number: 99R16743. Unpublished study prepared by Springborn

Laboratories, Inc. 282 p.

MRID: 47778802

Miller, R. (2009) Product Properties: Color, Physical State, Odor, Stability to Normal and

Elevated Temperatures, Oxidation/Reduction: Chemical Incompatibility, pH, UV/Visible

Absorption, Melting Point/Melting Range, Density, Partition Coefficient (n-Octanol/Water),

Water Solubility, and Vapor Pressure (Iprodione Technical). Project Number:

CHB/EX/609/011/P/l. Unpublished study prepared by PhibroWood, LLC. 37 p.

MRID: 47881501

Xu, T. (2009) Surface Water Monitoring for Residues ofIprodione in high Use Areas in the

United States. Study Number: RAIDXOOl. Unpublished study prepared by Bayer Cropscience.

251 p.

MRID: 48219201

Woodard, D. (2010) [Pheyl-UL-14C]-3,5-dichloroaniline: Aerobic Soil Metabolism in Two US

Soils. Study Number: MEIDY002. Unpublished study prepared by Bayer Cropscience. 83 p.

29
Appendix 1. Iprodione and Degradate Data

a eo ipro tone dezrada es t formed"In environment I a fat e stU dires

Degradate Chemical Name Study in Which Found (Maximum % Reference

Name of Applied) MRID

RP32596 1 3,5-dichloroaniline Aerobic Soil (9%, Day 30) 43091002

(or 3,5-DCA) Aerobic Soil (3.9%, Day 50) 44590501

Aerobic Aquatic (9.9%, Day 30) 42503801

Anaerobic Aquatic (3.6%, Day 275) 41755801

RP30228 3-(1-methy1ethyl)-N-(3,5- Hydrolysis (47%, pH 7, 125 hours) 41885401

dichloropheny1)-2,4-dioxo-1- Hydrolysis (93%, pH 9, 120 minutes) 44590501

imidazolidine-carboxamide Aerobic Soil (29%, Day 30) 42503801

Aerobic Aquatic (65%, Day 14) 41755801

Anaerobic Aquatic (67%, Day 14) 41877401

Terrestrial Field (0.47 ppm, Day 28) 43718301

Aquatic Field (0.13, I month after app)

RP25040 3-(3,5-dichlorophenyl)-2,4- Aerobic Soil (9.5%, Day 30) 43091002

dioxoimidazolidine

RP32490 3-(3,5-dichlorophenyl)-2,4- Aerobic Aquatic (15%, Day I) 42503801

dioxo-l-imidazolidine- Terrestrial Field (0.09 ppm, 8 months 41877401

carboxamide after app)

RP37176 N-(3,5-dichlorophenyl)-2-(1- Aquatic Field (0.13 ppm, Day 13) 43718301

methylethyl)-lureylenecarboxamide

RP35606 [(dichloro-3,5-phenyl)-I- Hydrolysis (12%, pH 5, Day 30) 41885401

isopropylcarbamoyl-3]-2-

acetic acid

RP36221 1-(3,5-dichlorophenyl)-5- Aerobic Soil (13%, Day 100) 44590501

isopropyl biuret

Unextractable Aerobic Soie (51%, Day 100) 44590501

residues Aerobic Soil (76%, Day 276) 43091002

Aerobic Aquatic (8%, Day 30) 42503801

Anaerobic Aquatic (29%,6 months) 41755801

T hI f i

1. The terrestnal field studies did not analyze for 3,5-DCA. Storage sample recovenes for 3,5-DCA in the

aquatic field were only 18%; thus, it was not suitable for characterizing the formation or persistence of

3,5-DCA.

2. Unextractable residues not measured, but total extractable residues were at 49% at Day 100.

ChenucaItt S rue ure or iprod"ione an mawr dd earada es t

Chemical Structure

Iprodione r CH,

0=<'JNANH~ - CH. "-d -, Cl

3,5-Dichloroaniline CI\

RP32596 ?>--~ 01

30
Chemical Structure

:3- l-methylethyl)-N-(3,5-dichloroph~nyl)-

2,4-dIOXO- (, l'-imidazolidine-carboxamide

co-~

*

RP30228

Q

~CE(CE')' 3-(3,5-dichlor~p~enyl)-2,4- H

dioxoimidazolidine 0 CI

RP25040 J-Y-©

CI

3-(3,5-dichlorophenyl)-2,,4-dioxo-l- n

od_L~ imidazolidine-carboxamide

RP32490

C1 C3

N-(3,5-dichlorophen~1)-2-(I-methylethyl)-

l-ureylenecarboxamide cp- /~ , NHCOCt\NHCOCH<, RP37176

CHI

- Cl

[(dichloro-3,5-phenyl)-1- , id CI Cli. OOOH

~NH........LC-NH-cHICHJ'

isopropy ' Icarbamoyl-3]-2-acetIc aCI

II \I

RP35606

o 0 C

5 ' opyl biuret b---rm-A-naC:

1-(3,5-dichlorophenyl)- -isopr

RP3622 1

Cl

31
Proposed route of degradation, from aerobic soil metabolism study (MRID 43091002)

structure tonrlrmed

b)' tC/MS ll.P2~040

*

.~ 0 e, "'~ I'

, ~)

... ::~~. -~... .,)=

i""'''~'':'-o

'::1"- .....

ri"

CQ.H(;HIc:....COOIot

I C::l ;'-'='"'QI o~_I/ .•.

el

llPJOZZB

32

)

c'

......} '<::

;, ... '.~'

":"":1

RPl6112

I<PJ6 U9'
Appendix 2. Usage Data from USGS NA WQA Program

IPRODIONE - fungicide

2002estimated annualagricultural use

Averageannualuse of active ingredient (pounds persquaremileof agricultural landincounty)

o no estimated use

[] 0.001 to 0.003

III 0.004 to 0.009

o 0.01 to 0.042

o 0.043 to 0.345

• >=0.346

Total Percent

Crops nnunds anplled n~tlonal use

cotton 133254 27.04

almonds 116979 23.74

potatoes 57463 11.66

lettuce 54408 11.04

dry onions 24562 4.98

grapes 19097 3.87

peaches 19084 3.87 carrots 18930 3.84

cherries 9973 2.02

nectarines 7688 1.56

VINCLOZOLIN - fungicide

2002 estimatedannualagriculturaluse

Average annual use of active Ingredient (poundspersquare mile of agricultural

land incounty)

o no estimateduse

o 0.001 to 0.002

0.003 to 0.008

o 0.009 to 0.034

IJ 0.035 to 0.146

• >=0.147

Crops

lettuce

green beans

Idwlfrun

33

Total

Pounds Applied

30011

20611

1218

Percent

National Use

58.00

39.84

2.35
j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j

j