Page 2 of 38



### be conducted as part of the registration r eview of the fungicide

, imazalil and imazalil
sulfate

. The revisions update the preliminary problem formulation (DP 411863)

. They reflect additional data submitted to the Agency for review and a more detailed description of the requested chronic sediment toxicity data request.

The problem formulation draws on information from both open literature and studies submitted by the techni cal registrants in response to data requirements. This document is intended to provide an overview of what is currently known regarding the environmental fate and ecological effects associated with imazalil and imazalil sulfate and their degradates
and ou tlines uncertainties regarding attributes of the parent compound and its transformation products . It describes the preliminary ecological risk hypothesis and the processes that will be used during the completion of drinking water and ecological risk

asses sments in support of re registration. This document also recommends studies that
should be included in a data call

- in (DCI) to address uncertainties surrounding the environmental fate and potential ecolog ical effects of imazalil and imazalil sulfate

.Page 3 of 38



# Revised Problem Formulation for the Environmental Fate and Ecological Risk , Endangered Species
, a nd Drinking Water Assessment s in Support of the
R eg istration Review of Imazalil and Imazalil Sulfate

1

- [2

- (2,4

- dichlorophenyl)

- 2

- (2

- propen

- 1

- yloxy)ethyl]

- 1H

- imidazole
1

- [2

- (2, 4

- dichlorophenyl)

- 2

- (2

- propen

- 1

- y Tile loxy)ethyl]

- 1H

- imidazolium hydrogen sulfate (CAS 3555

- 44

- 0 and 58594

- 72

- 2)

Environmental Fate and Effects Division Team:
Environmental Risk Branch II Christine Hartless, Ph.D., Wildlife Biologist R. David Jones, Ph.D. Senior Agronomist Reviewed by: James Lin, Ph.D. Chemist Jean Holmes, DVM, RAPL
Brian Anderson , Branch Chief U. S. Environmental Protection Agency Office of Pesticide Programs
1200 Pennsylvania Ave., NW
Mail Code 7507P Washington, DC 20460

Antimicrobials Division Team:

Laura Parsons

, 

### Acting Associate Branch Chief Bill Erickson, Biologist Cl Cl O N

NPage 4 of 38 

### Table of Contents

1. Executive summary

................................ ................................ ................................ ........ 5
2. Introduction

................................ ................................ ................................ .................... 6
3. Use Characterization

................................ ................................ ................................ ...... 6
4. Conclusions from Previous Risk Assessments

................................ .............................. 9 5. Environmental Fate and Transport

................................ ................................ ................ 10 6. Receptors

................................ ................................ ................................ ...................... 14 7. Exposure Pathways of Concern

................................ ................................ ................... 16 8. Analysis Plan

................................ ................................ ................................ ................ 16
8.1 Stressors of Concern

................................ ................................ ........................... 16
8.2 Measures of Exposure

................................ ................................ ........................ 17
8.3 Measures of Effect

................................ ................................ ............................. 18 9. Endangered Species Assessment

................................ ................................ ................. 18
10. Endocrine Disruptor Screening Program

................................ ................................ ... 18 11. Preliminary Identification of Data Gaps

................................ ................................ .... 18
11.1. Fate

................................ ................................ ................................ ...................... 18
11.2. Effects

................................ ................................ ................................ ................. 21
12. References

................................ ................................ ................................ .................. 26

Appendix A . Screening Ground Water Exposure Assessment Using PRZM GW

....... 31 Appendix B. Screening Level Models to Evaluate Potential Importance of Drinking Water and Inhalation Exposure Pathways

................................ ................................ .... 33 Appendix C. Data Justification Tables for Chronic Sediment Toxicity Studi es

......... 35Page 5 of 38



## 1. Executive summary

The Environmental Fate and Effects Division (EFED) and Antimicrobials Division (AD)
have completed the preliminary problem formulation for the ecological risk, environmental fate, endangered species, and drinking water assessments to be conducted as part of the registration review of imazalil and imazalil sulfate . The problem formulation des cribes the
methods planned to be used during the completion of drinking water and ecological r isk assessments in support of registration review and provide s an ove rview of the environmental fate, ecological effects , and potential risks associated with the use of
imazalil and imazalil sulfate as well as uncertain ties unique to risk assessment of imazalil
and imazalil sulfate . This document also identifies additional studies that would be beneficial to the conduct of an ecological risk assessment.

Data ne eds for ecological effects are:

 Freshwater fish early

- life stage (850.1400 ) 1



###  Estuarine/marine acute fish toxicity (850.1075)

 Whole Sediment Chronic Invertebrate Toxicity (Freshwater , two species , non

guideline ) 2



###  Whole Sediment Chronic Invertebrate Toxicity (Estuarine/marine , non

- guideline ) 3



###  Acute passerine toxicity (850.2100)

 Earthworm Subchronic Toxicity Test (850.3100) 4



###  Honey bee acute contact toxicity (850.3020) 5



###  Honey bee acute oral toxicity (non

- guideline) 6 

### Data needed for fate and exposure assessment are:

 Aerobic soil metabolism (835.4100) for three additional soils

 Aqueous photolysis (835.2240 )

 Laboratory Volatility (835.1410) [to be conducted in a basic environment]

 Terrestrial Field Dissipation Study (835.6100)

 Bioaccumulation in Fish (850.173 0)

 Environmental chemistry method for soil (850.6100)

1 A study has been submitted to the Agency and is currently under review (MRID 49106401).

2 Requested freshwater studies are a 42

- day study with Hyallela azteca and a 56

- day study with
Chironomus dilutus or C. tentans. Both are found in Second Edition EPA/600/R

- 99/064, Duluth, MN. A
chronic C. riparius study has been submitted to the Agency and is currently under review (MRID
49215906 ).

3 Requested estuarine/mari ne study is a 28

- day study conducted with the Amphipod Leptocheirus plumulosa found in First Edition, EPA Report 600/R

- 01/020, March 2001.

4 A study has been submitted to the Agency and is currently under review (MRID 49215905).

5 A study has been submitt ed to the Agency and is currently under review (MRID 49215902 ).

6 A study has been submitted to the Agency and is currently under review (MRID 49215903 ).Page 6 of 38



## 2

. Introduction

Imazalil and imazalil sulfate are imidazole systemic fungicide s

. They are specifically
effective in controlling seed

- and soil

- borne pathogens, such as Pyrenophora, Fusarium,
and Septoria fungi. Imazalil and imazalil sulfate are imidazole fungicide s which are sterol demethylation inhibitor s (SDI). The fungicidal action interferes with ergosterol synthesis of fungi by inhibiting the sterol C 14 

### demethylation process. Physiologically, imazalil inhibits gibberellic acid biosynthesis and production of demethyl sterol in seedlings. In
th e demethylation process, the 14

- α

- methyl group in a sterol is removed by three
NADPH

- dependent oxygenas e's oxidative reactions which are catalyzed by a

cy tochrome

- P450 enzyme. Imazalil, as an SDI, inhibits spore germination, activates uncoordinated chitin syntheses (which affects budding fungi), and accumulates free fatty acids (which is toxic to fungal cells).

The uses in the profile to be evaluated by E FED include 1) terrestrial feed crop (barley, wheat, and triticale seed treatment), 2) indoor food (post

- harvest citrus fruit treatment), and 3) greenhouse fogger (bedding plants, cut flowers, flowering plants (baskets and hanging), foliage, ornamentals, and perennials)

. Note the only outdoor uses are seed treatments.

The use in the profile to be evaluated by AD includes indoor non

- food (egg hatc hing
facilit ies and equipment disinfection)

. Treatment of egg hatching facilities and equipment
disinfection is considered to be an agricultural premise u se for purposes of risk assessment

. As labeled, this use is not expected to result in environmental ex posures because the spray is allowed to dry prior to introduction of eggs. AD is not requesting any additional environmental fate or ecotoxicology data to evaluate this use.

EFED evaluated the most recent ecological risk assessments for imazalil and imaz alil
sulfate in association with the update d toxicity, exposure, and usage information to determine if sufficient data are available and if further updates are needed to support registration review. In addition, EFED considered the latest Agency science p olicies and risk assessment methodologies. The structure s of imazalil and imazalil sulfate , as well as the chemical names and other identifiers can be found in the chemical identity table in
Section 5 of this document.



## 3. Use Characterization

The chem ical profile produced by Biological and Economic Analysis Division ( BEAD )

, located in the docket, lists the use patterns of maxim um exposures for the current uses of
imazalil and imazalil sulfate

. The chemical profile includes both a summary of labeled uses and rates as well as a summary of available reported usage data. EFED will use application scenarios that result in maximum exposure scenarios for a given use for the risk assessment. Any absenc e of 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

.Page 7 of 38



### The use profile to be utilized in t he ecological risk assessment include 1) terrestrial feed crop (barley, wheat, and triticale seed treatment), 2) indoor food (post

- harvest citrus fruit treatment), and 3 ) greenhouse fogger (bedding plants, cut flowers, flowering plants (baskets and hanging ), foliage, ornamentals, and perennials) , and 4 ) indoor non

- food (egg hatching facilities and equipment disinfection)

. M aximum application rates, application methods, and affiliated labels are outlined below for f ield uses ( Table 1 ) and non

- field uses ( Ta ble 2 )

.

Table 1 . Methods and rates of application of currently registered used of imazalil (field uses).

Crop Max. Single App.

Rate Annual

Max. No. of Apps. Application

Intervals (days) Application

Method End

- use

Product
Labels

Wheat 0 .0001 lb a.i. / lb seed 1 NA seed treatment 264

- 976
264

- 977
83991

- 1 *
83991

- 2 *

Barley 0 .0001 lb a.i. / lb seed 1 NA seed treatment 264

- 976
264

- 977
83991

- 1 *
83991

- 2 *

Triticale 0 .00003523 lb a.i. /

lb seed 1 NA seed treatment 264

- 976 *
264

- 977

*label with the highest ratePage 8 of 38



### Table 2. Methods and rates of application of currently registered used of imazalil and imazalil sulfate ( indoor and greenhouse uses).

Active Ingredient/ Commodity Max. Single App.
Rate Annual

Max. No. of Apps. Application

Intervals (days) Application

Method End

- use

Product
Labels

Imazalil
Citrus ** 0.6265 lb a.i./100 gal. 1 NA Dip treatment

Drench

Wash 43813

- 6

66222

- 20

2792

- 51

66222

- 100*

Imazalil

Citrus 0.8353 lb a.i./100 gal. 1 NA Spray 43813

- 6

66222

- 20

2792

- 51

66222

- 100*

Imazalil

Citrus 3.3 lb a.i./100 gal. 1 NA Wax treatment 43813

- 6*

66222

- 20*

2792

- 51

66222

- 100*

Imazalil

Citrus 3.3 lb a.i./100 gal. 1 NA Foam 66222

- 100*

Imazalil sulfate

Citrus 0.8348 lb a.i./100 gal. 1 NA Dip treatment

Drench

Wash 43813

- 26*

43813

- 38*

Imazalil sulfate

Citrus 1.1 lb a.i./
100 gal. 1 NA Spray 43813

- 26*

43813

- 38*

Imazalil sulfate

Citrus 2.2 lb a.i./
100 gal. 1 NA Wax treatment 43813

- 38*

Imazalil

Ornamental herbaceous plants,
Ornamental non

flowering plants, Ornamental woody
shrubs and vines 0.704 lb a.i./acre 8 7 days Aerosol, fog, or fumigation. 499

- 508 *

Imazalil
Poultry and turkey hatchery equipment. 1 mL 0.15%

solution per 10 ft 3 NS NS Aerosol, fog, or fumigation. 773

- 55 *

773

- 56 *

53883

- 327 *

*label with the highest rate

** All imazalil and imazalil sulfate citrus labels contain the following statement: “Do not discharge effluent containing this product into lakes, streams, ponds, estuaries, oceans, or other waters unless in accordance with the requirements of a National Pollutan t Discharge Elimination System (NPDES) permit and the permitting authority has been notified in writing prior to discharge. Do not discharge effluent containing this product to sewer systems without previously notifying the sewage treatment plant authority . For guidance, contact your State Water Board or Regional Office of the Environmental Protection Agency.” NA = not applicable NS =not specifiedPage 9 of 38



## 4

. Conclusions from Previous Risk Assessments

The Agency has conducted previous ecologi cal risk assessments on imazalil that serve as a basis for this problem formulation. These are briefly summarized below. No ecological risk assessments have been conducted by the Agency for imazalil sulfate. No endangered species assessments have been conducted for either imazalil or imazalil sulfate.

At the time the EFED Reregistration Eligibility Decision (RED) Chapter was signed ( April 18, 2001)

, imazalil was registered as a fungicide for seed treatment of small grains (wheat and barley), for post

- harvest use on citrus fruits by water and wax application, and as a
disinfectant in chicken hatching equipment . The EFED risk assessment did not result in any RQs that exceeded levels of concern for either terrest rial or aquatic non

- target organisms , and , therefore, imazalil was not expected to represent a risk to the environment. No previous ecological risk assessment has been located for the triticale seed treatment

use. The use rate for triticale is approximatel y 1/3 that of wheat and barley; therefore, the risks from triticale would be expected to be less than those for wheat or barley. In the RED,

EFED expressed concerns regarding the endocrine disrupting potential of imazalil based
on the chemical's mode of ac tion as a sterol inhibitor and on reproductive effects (eggshell thinning) observed in chronic toxicity studies of mallard ducks.

Environmental fate data were complete at the time the RED was completed, and no additional data were required. Ecological ef fect data were relatively complete at the time
the RED was finalized

. B ased on the data requirements for seed treatment chemicals, the registrant was required to submit aquatic plant acute toxicity studies for two species. Additionally, because of concerns regarding the endocrine disrupting potential of imazalil,

EFED requested that additional tests be conducted to better characterize these potential effects once the appropriate methodology has been developed. Imazalil toxicity studies for Lemna gibba and Selenastrum capricornutum were submitted, reviewed, and classified as Supplemental (MRIDs 46818201 and 46818202 , respectively ). A short

- term reproduction zebrafish ( Danio rerio ) assay with imazalil f ollowing OECD 229 was submitted to the Agency and is currently under review (MRID 49106401)

.

A drinking water exposure assessment for use in the human dietary risk assessment was completed for the RED. This assessment found that an upper

- bound concentrati on in
surface water from the use of imazalil as a seed treatment was 0.072 μg∙L

- 1 

### and that the concentration is ground water was ‘negligible’. An assessment of ground using PRZM

GW performed for this assessment showed upper bound concentrations in ground w ater

we re no higher than 5 x 10

- 3 

### μg∙L

- 1 

### . (See Appendix A )

In 2006, EFED reviewed a Section 3 request to use imazalil as a greenhouse fogger (bedding plants, cut flowers, flowering plants (baskets and hanging), foliage, ornamentals, and perennials) (DP Barcode: 326607). EFED concluded that no environmental exposure was anticipated and that th e product

, when label directions were followed

, will have no
effect on non

- target organisms as the product was a total release aerosol formulation intended strictly for non

- food, indoor greenhouse use.Page 10 of 38



## 5

. Environmental Fate and Transport

Registrant

- submitted data defining the physical, chemical, fate and transport characteristics
associated with imazalil are summarized in Table 3

. EFED is not aware of any monitoring
data for imazalil or imazalil sulfate.

Table 3. General physico

- chemical and environmental fate properties of imazalil

.

Parameter Value Reference

Selected Physical/Chemical Parameters

Molecular Mass imazalil: 297.18 g∙ mol

- 1 imazalil sulfate: 395.26 g∙mol

- 1 calculated

Water Solubility imazalil: 0.3 mg∙L

- 1 (temperature unspecified) imazalil sulfate: 500 mg∙L

- 1 (temperature

unspecified) Goodwine (1987)

Vapor pressure 1.52 x 10

- 6 torr at 25 o C MRID 44107218

Density 1.40 kg∙L

- 1 @ 20 o C MRID 44107208

Henry's Law Constant 1.98 x 10

- 6 atm∙m 3 ∙mol

- 1 calculated

Octanol/Water Partition Coefficient

(K ow ) pH 5: 18,600

pH 7: 10,000

pH 9: 15,800 MRID 4410721 1

pK a 6.48 MRID 44107210

Hydrolysis t 1/2 pH 5

pH 7 pH 9 no evidence of degradation at all pHs MRID 00115272

Aqueous Photolysis 1.5 d MRID 40926701
MRID 41350801

MRID 92072015

Aerobic Soil metabolism t 1⁄2 Watervliet loam : 157 days (parent) @ 25oC
468 d (parent + unextracted residues ) @ 25oC MRID 00148314

MRID 00158160

Batch Equilibrium K f =28.9 L∙kg

- 1

– Kessel sand 80 L∙kg

- 1

- Groostrees loam y s and t 137.6 L∙kg

- 1

- Ekeren

- Laar sandy loam
187.8 L∙kg

- 1

– Watervliet loam 187.9 L∙kg

- 1

– Haacht silt loam 195.3 L∙kg

- 1

- Ekeren silt loam
110

- L∙kg

- 1 Tongeren silt loam 111.8 L∙kg

- 1 Dronten silty clay loam 1/n values ranged from 0.71

- 0. 98 van Leemput, 1986

MRID 00158160

Column Leaching no detected movement in columns (30

- cm length) of sandy loam, silty clay loam, silt loam, and

loamy sand soils MRID 00148072

MRID 00158160

MRID 91072017Page 11 of 38



### The dominant route of dissipation of imazalil is expected to be aerobic metabolism in terrestrial environments (T 1⁄2 

### = 157 d)

. Partition coefficients vary with pH, and are not correlated with soil organic carbon content. The magnitude of the adsorption coefficients indicates that imazalil is not prone to leach ing

. There is some uncertainty associated with
the environmen tal fate of imazalil because the pKa of 6.48, (the acid equilibrium constant) is in the middle of the range of pHs commonly found in the environment, so the form of imazalil, the protonated acid form or the neutral basic form will vary with pH. At a soil o r water pH of 6.48, there will be equal amounts of both species present. At lower pHs, the cationic form will predominate and at higher pHs, there will be more of the neutral conjugate base form. Since these two forms will have different properties, the

en vironmental fate profile is likely different for the two forms and there is currently insufficient data to evaluate how imazalil behavior changes as a function of pH. Note that
the active ingredient imazalil (PC code: 111901) is the basic form while imazal il hydrogen
sulfate is the salt of the acid f or m (PC Code: 111902). The form of imazalil which is applied is not important in determining the fate and transport pro perties as the acid

- base buffe ring capacity in the envir onment is quite large and the f o r m o f imazalil which will be present in the environment is determined by the local pH and not by form applied. T here are currently no acceptable field dissipation studies so the fate assessment based on laboratory data cannot be evaluated against field results

. No monitoring data has been identified for
imazalil.

Physical and Chemical Properties

The reported solubility of imazalil is 0.3 mg∙L

- 1 

### (Goodwine 1987). However, details describing the measurement, such as the temperature and the pH, were not provided so there is some uncertainty regarding this value. The same source reported the solubility of imazalil sulfate as 500 mg∙L

- 1



### . Because imazalil is a Lowery

- Bronsted base, its solubility would be expected to vary with pH

. In addition, t he solubility of the c onjugate acid depends somewhat on the counter anion. For example imazalil nitrate solubility is 24 mg∙L

- 1



### . Imazalil is not expected to volatilize with a vapor pressure of 1.52 x 10

- 6 

### torr at 25 o 

### C . The
octanol

- water partition coefficient varies with pH fro m 10,000 at pH 7 to 18,000 at pH 5. These values suggest that imazalil may bioconcentrate, but no bioconcentration data are available.

Abiotic Degradation.

There is no evidence that imazalil degrades by hydrolysis at any pH. Some imazalil may be removed by runoff and be susceptible to photolysis in aquatic systems, so aqueous photolysis may be an important route of degradation. Imazalil degrades moderately rapidly in aqueous syste ms with a 1.5 d half

- life. There were two major degradates, only one of
which was identified: N

- ([2

- (2,4

- dichloropheny1)

- 2

- (2

- propenyloxy) ethyl] formamide which was at 17.8% of the applied amount at 6 d after initiation the experiment ( Figure
1.1 and Table 4 ) . The other major (unidentified) degradate, labeled ‘F

- I ’ by the registrant was at 72% of the applied at 6 d. This may have consisted of more than one compound as it was in a peak at the start of the chromatogram. This peak did not appear until 1.5 d afterPage 12 of 38



### the start of the experiment indicating that it is a sec ondary or tertiary degradate. I mazal il is not expected to degrade by photolysis in terrestrial systems as the seed treatment use results in the imazalil being below the surface and not exposed to light.

Figure 1. Imazalil environmental degradates:

F2 : N

- [2

- (2,4

- dichlorophenyl)

- 2

- hydroxyethyl]formamide; F

- IV: 1

- [2

- (2,4

- dichlorophenyl)

- 2

- hydroxyethyl

- IH

- imidazole; FV

- A : N

- [[[2

- (2,4

- dichlorophenyl)

- 2

- (Z

- propenyoxy~ethyl]imino]methyl]

- 2,4

- dichloro

- beta

- (2

- propeny1oxy) benzenethamine; F

- VII: N

- ([2

- (2,4

- dichloropheny1)

- 2

- (2

- propenyloxy)ethyl]formamide

.Page 13 of 38



### Metabolic Degradation

.

A single aerobic soil metabolism study is available to describe the degradation of imazalil
in aerobic soils. No acceptable aquatic metabolism data is available and no anaerobic soil metabolism study has been conducted. This study was performed on a Watervliet silt loam from Belgium and found the imazalil degraded with a half

- life of 157 d. However, there were substantial unextracted, unidentified residues (31%) present at the end of the study at
366 d

, and these residues present a significant uncertainty in the degradation rate of the imazalil in aerobic soil. If these residues are assumed to be the parent or degradates which are of similar toxicity to the parent, the e stimated half

- life is 487 d. Since these residues were not identified their nature is unknown. A significant fraction of the total degradate formed during the study was carbon dioxide (20.8%). This suggests that these residues may
be intermediate breakdow n products of imazalil. An additional uncertainty results from having only a single study conducted at a single pH as the acid and base forms of imazalil may have different degradation profiles.

Other than CO 2 

### , there were two minor degradates formed during the aerobic soil metabolism ( Table 4 ). Both of these compounds were measured as a single fraction which peaked at a maximum level of 7% of the applied at 70 days after application, Component I was confirmed (by GC/MS) to be 1

- [2

- (2, 4

- dichlo rophenyl)

- 2

- hydroxyethyl

- IH

imidazole. The structure of component II was not known.

Table 4. The Maximum Amount of Degradates Formed in Laboratory Degradation Studies by Imazalil and the Time When the Maximum Occurred.

Degradate Hydrolysis Photolysis Aerobic Soil
Metabolism

CO 2 -- 1.5% @ 6 d * 20.8%

1

- [2

- (2,4

- dichlorophenyl)

- 2

- hydroxyethyl

- IH

- imidazole

-- <7% @ 70 d

N

- ([2

- (2,4

- dichloropheny1)

- 2

- (2

- propenyloxy)ethyl]formamide -- 17.8% @ 6 d *

N

- [2

- (2,4

- dichlorophenyl)

- 2

- hydroxyethyl]formamide

-- 8.8% @ 6 d *

N

- [[[2

- (2,4

- dichlorophenyl)

- 2

- (Z

propenyoxy~ethyl]imino]methyl]

- 2,4

- dichloro

- beta

- (2

- propeny1oxy) benzenethamine -- 5.8% @ 2 d

Unidentified major photolysis degradate F1

-- 72.2% @ 6 d*
Unidentified minor metabolism degradate

-- <7% @ 70 d Unidentified minor photolysis degradate F3

-- 5.2% @ 6 d* Unidentified minor photolysis degradate F3

-- 6.7%@ 6 d*
Unextracted residues 31% @ 366 d* * The time of maximum occurrence of the degradate was at the termination of the study.Page 14 of 38



### Mobility

A soil column leaching study for imazalil showed no movement of residues through soil
and no residues in the leachate in four different soil columns. A batch equilibrium study evaluated adsorption in eight Belgian soils ( Table 3 ). K f 

### values rang ed from 28.9 to 187.9 L·kg

- 1 

### . No correlation with organic carbon content was found across the soils. However,

K f 

### was significantly correlated with pH with a regression equation of K f 

### = 48. 1 ( pH )

- 182

. This is expected as the conjugate acid and base forms would be expected to have difference propensities for adsorption. The acid form likely binds to the cation exchange complex, as it has a positive charge and the basic form likely binds to the soil orga nic matter. However, there is insufficient data available to establish the nature of the binding of the two forms separate from the pH effect with the amount of data available.



## 6

. Receptors

Table 5 provides a summary of the taxonomic groups and the surro gate species tested to characterize the potential acute and chronic ec ological effects of imazalil

. In addition, the table provides a preliminary overview of the potential acute toxicity of imazalil by providing the acute toxicity classifications. No ecot oxicity data are available for imazalil sulfate or any degradates of imazalil.

Technical grade imazalil is classified as moderately toxic to freshwater fish and aquatic invertebrates on an acute exposure basis. Chronic exposure effect data to imazalil fo r freshwater fish are still under review. No data were available for estuarine/marine organisms. Toxic effects were observed in both freshwater vascular and non

- vascular aquatic plants. EPA does not currently classify toxicity to aquatic plants.

Imazalil is slightly toxic to birds on an acute oral basis, practically non

- toxic to birds on a subacute dietary exposure basis, and moderately toxic to mammals on an acute oral exposure basis. For bobwhite quail, chronic exposure to imazalil r esulted in reduced adult body weights, and for mallard ducks, chronic exposure to imazalil resulted in reduced second generation viability, hatchability, and survival as well as reduction in eggshell thickness and egg production. Chronic exposure to laboratory rats resulted in reductions in body weight, litter size and gestation length. Data on toxicity of imazalil to honeybees and terrestrial plants have not been submitted to the Agency.

A review of the Ecological Incident Information System (EIIS, version 2.1 ) and the Av ian Monitoring Information System (AIMS) was completed on November 15, 2013, and no ecological incidents involving imazalil or imazalil sulfate were identified. Incident databases will be reviewed again at the time of the risk assessment.Page 15 of 38



### Table 5. Test Species Evaluated for Assessing Potential Ecological Effects of Imazalil.

Taxonomic Group Study

Type Tested Species Toxicity Endpoint Acute Toxicity
Classification /
NOAEC most sensitive endpoint ( s ) Source
MRID

Birds 1 Acute oral Ring

- necked
Pheasant
Phasianus colchicus LD 50 = 1912 mg a.i./kg

- bw Slightly toxic 163243

Dietary Mallard duck

( Anas platyrhynchos ) LC 50 >5620 mg a.i./kg

- diet Practically non

- toxic 30542

Northern bobwhite quail (Colinus virginianus) LC 50 >5620 mg a.i./kg

- diet Practically non

- toxic 30543

Chronic Mallard duck NOAEC = 250 mg a.i./kg

- diet
LOAEC = 500 mg a.i./kg

- diet Second generation viability, hatchability,
and survival. Reduction in eggshell thickness and egg production. 42039801

Northern bobwhite quail NOAEC = 250 mg a.i./kg

- diet

LOAEC = 500 mg a.i./kg

- diet Adult body weight change 41663801

Mammals Acute Laboratory rat ( Rattus norvegicus ) LD 50 = 343 mg a.i./kg

- bw Moderately toxic 00031596

Chronic Laboratory rat NOAEC = 300 mg a.i./kg

- diet LOAEC = 1,200 mg a.i./kg

diet Body weight; litter size; duration of gestation 42570701

Insects No data

Freshwater
fish 2 Acute Rainbow trout Oncorhynchus mykiss LC 50 = 1.48 mg a.i./L m oderately toxic 41606102

Chronic Zebrafish

Danio rerio Under review 49106401

Freshwater
invertebrates Acute Waterflea Daphnia magna EC 50 = 3.54 mg a.i./L moderately toxic 41606103

Chronic No data

Estuarine/
marine fish Acute and

Chronic No data

Estuarine/
marine
invertebrates Acute and

Chronic No data

Terrestrial plants Seedling

emergence/ vegetative vigor No data

Aquatic plants and algae Vascular Duckweed, Lemna gibba IC 50 = 0.35 mg

a.i./L 95% C.I.:
0.17

- 0.70 mg ai/L NOAEC = 0.0954 mg a.i./L Frond Number and Area
Under the Growth
Curve 46818201

Non

vascular Green alga

Selenastrum capricornutum IC 50 = 0.73 mg

a.i./L 95% C.I.:
0.58

- 0.91 mg ai/L NOAEC = 0.5 mg a.i./L Cell density 46818202

1 Birds represent surrogates for terrestrial

- phase amphibians and reptiles.

2 Freshwater fish may be surrogates for aquatic

- phase amphibians.Page 16 of 38



## 7

. Exposure Pathways of Concern

The environmental fate properties and use patterns of imazalil and imazalil sulfate indicate
that discharge of treated water from use on post

- harvest cit rus , leaching to ground water

, and runoff and movement of imazalil from treated seeds to the growing plant represent potential transport mechanisms of imazalil and im a zalil sulfate to aquatic and terrestrial organisms.

Drinking water and inhalation expo sure pathways were screened using the SIP (Screening Imbibition Program) and STIR (Screening Tool for Inhalation Risk) screening methods
SIP and STIR are described in detail at:
htt p://www.epa.gov/oppefed1/models/terrestrial/index.htm

. The inhalation exposure pathway was found to be an exposure pathway of low concern (no LOC exceedances are expected). Because of the high water solubility of imazalil, the drinking water pathway

was found to be an exposure pathway of potential concern. SIP and STIR results are presented in Appendix B

.



## 8

. Analysis Plan

8.1 Stressors of Concern

i. Ecological Risk

The stressors of ecologic al concern for terrestrial and aquatic organisms are imazalil and
imazalil sulfate. As discussed above in the fate assessment, once these two compounds are released into the environment, they will rapidly interconvert to one of the two forms according to the local en vironmental pH. While the environmental fate and toxicity data for imazalil do not distinguish between these two forms, it is likely that the environmental fate and toxicology properties differ for the two forms. Consequently, this assessment will

assume that the properties of both forms are the same

. An exception will be if Tier 2 aquatic modeling in necessary. In that case the assessment will consider changes in s oil

- water partitioning as a function of pH.

Because there is considerable uncertainty in th e nature of unextracted uncharacterized residues in the aerobic soil metabolism study, a total toxic residues approach is being used
to estimate the soil metabolism half

- life which considers the unextracted residues to be of equivalent toxicity as the pare nt. If risk threshold s are exceeded in assessments using this assumption, additional simulations will be performed using parent only half

- lives in order assess the amount of uncertainty in the risk assessment due to lack of characterization of
unextracted residues in this study.

ii. Drinking Water

If a new assessment is conducted, it will consider imazalil, imazalil sulfate, thePage 17 of 38



### unidentified

, unextracte d residues in metabolism study , and the single identified degradate,
1

- [2

- (2,4

- dichlorophenyl)

- 2

- hydroxyethyl

- IH

- imidazole in the drinking water exposure

assessment.



## 8.2 Measures of Exposure

i. Ecological 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 . E

- FAST and additional available exposure models may be used to assess use and discharge from post

- harvest citrus

treatmen t. E

- FAST is described in detail at http://www.epa.gov/oppt/exposure/pubs/efast.htm

. As imazalil is a systemic chemical, exposure to terrestrial organisms may occur when feeding on plants gro wing from the treated seed. Magnitude of residue data reviewed by HED will be used as screening level estimates of imazalil concentrations in various plant components

.

Screening level calculations suggested that drinking water pathway may be significant for terrestrial organisms . This exposure pathway may be further considered at the time of the
risk assessment ( Appendix B ).

The Agency is aware of monitoring conducted by federal and state agencies and this route of exposure will be considered in the assessment to the ex tent that data on imazalil
are available.

ii. Drinking Water in Human Dietary Risk Assessment

Because the estimates of fate and transport properties have changed since the RED (Lee, Liu, and Breithaupt, 2001), drinking water exposure will be re

- evaluated to support registration review. The Health Effects Division is currently reconsidering the cancer human health endpoint for imazalil. Changes in cancer classification may obviate the need for a drinking water exposure assessme nt, in which case not new assessment will be performed. The assessment will use the screening model FIRST for assessing exposure in surface water source drinking water and will use the models SCI

- GROW and PRZM

- GW for assessment exposure through ground wate r as according to current OPP guidance.

PRZM

- GW is currently in a one year evaluation period. Guidance for its use may be adjusted to better characterize exposure following that evaluation period

.Page 18 of 38 

## 8.3 Measures of Effect

T oxicity data presented in Section 3 of this problem formulation will be used to calculate risk quotients. Any additional information submitted by the registrant or found in the open literature prior to conduct of the risk assessment will also be considere d. The open literature 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 data 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 o f the affected communities.



## 9. Endangered Species Assessment

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA),
the Agency will evaluate risks to federally threatened and/or endangered (listed) species from registered us es of pesticides in registration review . The process for evaluating potential risks to listed species is further described at http://www.epa.gov/oppfead1/endanger/litstatus/riskas ses.htm

.



## 10

. Endocrine Disruptor Screening Program

Imazalil and imazalil sulfate wer e not included in 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/

.



## 11

. Preliminary Identification of Data Gaps

1 1. 1. Fate

The environmental fate data base for imazalil is not complete ( Table 6 ). Additional data is required to replace several studies which have been found to be invalid and to better describe the differential fate properties of imazalil’s conjugate acid and base forms. A new aqueous photolysis study is required s ince the study used to support reregistration has since been found to be invalid due to the use of a photosensitizer , acetone , in the test system. Additional aerobic soil metabolism studies in three soils are required to better describe how
imazalil’ s degr adation rate and products may change due to differences in environmental pH. The additional test systems should be conducted in soils with a range of pH from acid
to basic. A laboratory volatility study (835.1410) is needed to support the greenhouses so
th e exposure from imazalil in air can be assessed. This study is not required to support the indoor citrus use, or the seed treatment uses, where the pesticide would be expected to be
buried beneath the soil surface. Because the octanol

- water partition coeff icient is greater than 10,000, a BCF study is required (835.1730).Page 19 of 38



### An assessment o f the potential for exposure through ground

- water source drinking water was assessed to determine if additional data was needed to support this assessment (See Appendix A ). However, the concentrations estimated using PRZM

- GW were found to be well below thresholds of concern for human health from dietary routes and additional data

are not required to support this assessment.Page 20 of 38



### Table 6 . Available environm ental fate data for imaz alil and remaining data gaps.

158
Guideline (OPPTS) Description MRI D Classification Data Gap? C omments

835.1230 (163

- 1) Leaching MRID 00096425
MRID 00096426
MRID 00148072
MRID 00158560 un acceptable unacceptable acceptable acceptable no data requirement satisfied

835.1240 (163

- 1) Adsorption/Desorption van Le e mput, 1986
MRID 92072016
MRID 92072017 acceptable acceptable acceptable no data requirement satisfied

835.1410 (163

- 2) Laboratory Volatility none NA yes required as Henry’ Law Constant
> 10

- 6 atm∙m 3 ∙mol

- 1 and to support greenhouse use.

835.2120 (161

- 1) Hydrolysis MRID 00088226

MRID 000 55360

MRID 00 115272 unacceptable unacceptable acceptable no data requirement satisfied

835.2240 (161

- 2) Photodegradation in water MRID 000 96422

MRID 40926701
MRID 41350801

MRID 92072015 unacceptable supplemental supplemental supplemental yes Originally submitted study was
found to be invalid due to the use of a photosensitizer, acetone, in the test system.

835.2370 (161

- 4) Photodegradation in air none NA no not required

835.2410 (161

- 3) Photodegradation on soil none NA no not required to support current use
pattern

835.4100 (162

- 1) Aerobic soil metabolism MRID 000 96423
MRID 00 148314
MRID 00158560
MRID 92072034 unacceptable supplemental supplemental supplemental yes 3 additional soils are required to satisfy current guideline requirement

835.4200 (162

- 2) Anaerobic soil metabolism none NR no not required to support current use
patterns

835.4300 (162

- 4) Aerobic aquatic m etabolism none no risks below LOC with current data

835.4400 (162

- 3) Anaerobic Aquatic

Metabolism MRID 42012004 unacceptable no risks below LOC with current data

835.6100 (164

- 1) Terrestrial Field Dissipation MRID 000 96427 unacceptable yes

835.6200 (164

- 2) Aquatic Field Dissipation none NA no not required for current uses

835

- 6300 (164

- 3) Forestry Field Dissipation none NA no not required for current uses

850.1730 (165

- 4) Fish Bioconcentration Factor none NA yes K
oc > 10,000

850.6100 Environmental Chemistry

M ethod : S oil none NA yes supports terrestrial field dissipation study

850.6100 Environmental Chemistry

Method: Water none NA no no aquatic uses & and no aquatic
risk exceedances

NGS Drinking Water Treatment none NA no risks from drinking water are currently expected to be below
levels of concernPage 21 of 38



## 11. 2. Effects

Tables 7 and 8 identify ecological effects 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.

Freshwater fish early

- life stage ( 850.1400)

In the RED, EFED requested that additional tests be conducted to better characterize potential endocrine effects once the appropriate methodology was developed because of concerns regarding the endocrine disrupting potential of imazalil

. A study following
OE CD 229 conducted with zebrafish ( Danio rerio ) was submitted to the Agency (MRID
49106401 ). As the review by the Agency has not been completed, the data requirement is
still considered unmet. The review will be completed prior to risk assessment.

Whole Sed iment Chronic In vertebrate Toxicity (Freshwater and Estuarine/marine

, Special Non

- guideline Study )

There is a reasonable expectation of residue in freshwater and marine water sediments bodies as a result of effluent discharge from harvested citrus treatment. Presence and persistence in sediment is expected based on a K ow 

### >10,000 and on an aerobic soil

m etabolism half

- life of 157 days. Requested freshwater studies are a 42

- day study with Hyallela azteca and a 56

- day study with Chironomus dilutus or C. tentans. Both are
found in Second Edition EPA/600/R

- 99/064, Duluth, MN. Requested estuarine/marine study is a 28

- day study conducted with the Amphipod Leptocheirus plumulosa found in First Edition, EPA Report 600/R

- 01/020, March 2001. A detailed data justification is provided in Appendix C

.

Acute passerine toxicity (850.2100)

The revised Part 158 data requ irements specify that acute avian oral toxicity data be submitted for either one waterfowl or one upland game species and one passerine species. The available acute oral toxicity data, when compared to estimated environmental concentrations, indicate that levels of concern are exceeded for birds on an acute basis. Because passerine species have higher metabolic rates due to their smaller sizes than either waterfowl or upland game bird species and because they may utilize different metabolic pathways, they m ay be more or less sensitive to imazalil . In order to properly characterize risk to passerines, an avian oral toxicity test is required for passerine birds. A passerine study protocol must be submitted for review by the Agency prior to initiation of
the st udy. These data will be used to refine the screening

- level risk assessment by determining whether there are differences in avian species sensitivity to imazalil between currently tested passerine and upland game and/or waterfowl species that are beyond the simple allometric predictions currently employed in the absence of such passerine data. The current extrapolation method may be under

- or over

- estimating risks to passerines. If data are not submitted, than risk to passerines from acute exposure to imazalil will be
assumed.Page 22 of 38



### Honey bee acute contact toxicity (850.3020) and Honey bee acute oral toxicity (non

guideline)

At this time, no reviewed data are available to define the toxicity of imazalil to honey bees on an acute exposure basis. Given that the chemical is a systemic compound , it will
be available to bees through contact and consumption of the growing plant and pollen. Although the oral toxicity study is not an EPA guideline, guidelines are available ( e.g ., OECD 213) . The data will reduce uncertainties associated with the current risk assessment for terrestrial insects and will improve the Agency’s understanding of the potential effects of imazalil on terr estrial species. Honey bee acute contact and oral toxicity studies were submitted to the Agency (MRIDs 49215902 and 49215903 ). As the
review s by the Agency have not been completed, the data requirement s are still
considered unmet. The review s will be comp leted prior to risk assessment.

Earthworm Subchronic Toxicity Test (850.3100)

At this time, no data are available have been submitted to the Agency to evaluate the toxicity of imazalil to earthworms or terrestrial invertebrates . Given that the chemical is applied as treated seed, it will be available not only through consumption of and contact with the seed and growing plant, as well as consumption of and contact with the surrounding soil

. An earthworm toxicity study was submitted to the Age ncy (MRID
49215904 ). The review will be completed prior to risk assessment.

Table 7 . Available ecological effects data for aquatic organisms e xposed to imazalil and remaining data gaps.

OCSPP
Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Are data

needed to
conduct
risk
assessment? Justification and Assumptions

EPA will Make in Absence of

Data

850.1010 Freshwater

invertebrate acute toxicity 41606103 Acceptable No

--

850.1025
850.1035
850.1045
850.1055 Saltwater

invertebrate acute toxicity (None) (N/A) No Data have not been submitted to fulfill this guideline. A data gap was
not identified as these data are not necessary for risk assessment at this
time.

850.1075 Freshwater fish

acute toxicity 4160610 1 Acceptable No

--

41606102 Acceptable

850.1075 Saltwater fish

acute toxicity (None) (N/A) Yes

850.1300 Freshwater

invertebrate life cycle (None) (N/A) No Data have not been submitted to fulfill this guideline. A data gap was

not identified as these data are not necessary for risk assessment at this
time.Page 23 of 38 OCSPP
Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Are data

needed to
conduct
risk
assessment? Justification and Assumptions

EPA will Make in Absence of

Data

850.1350 Saltwater

invertebrates life cycle (None) (N/A) No Data have not been submitted to fulfill this guideline. A data gap was
not identified as these data are not necessary for risk assessment at this
time.

850.1400 Freshwater fish

early

- life stage 49106401 Under review Yes Data requirement may be satisfied pending completion of review (MRID 49106 4 01).

850.1400 Saltwater fish

early

- life stage (None) (N/A) No Data have not been submitted to fulfill this guideline. A data gap was
not identified as these data are not necessary for risk assessment at this
time.

850.1500 Fish life cycle (None) (N/A) No Data have not been submitted to fulfill this guideline. A data gap was
not identified as these data are not necessary for risk assessment at this
time.

Special Study Toxicity and

Bioaccumulation
of Sediment

associated
Contaminants
with Freshwater
Invertebrates. 1 (None) (N/A) Yes There is a reasonable expectation of
residue in freshwater and marine
water sediments bodies as a result of effluent discharge from harvested
citrus treatment. Presence and persistence in sediment is expected
based on a K ow >10,000 and an
aerobic soil meta bolism half

- life of 157 days. Special Study Whole Sediment

Lifecycle Toxicity Test
with Estuarine
Invertebrates. 2 (None) (N/A) Yes

850.4400 Aquatic plant

Toxicity Test using Lemna

spp. 46818201 Supplemental No

--

850.4500 Algal toxicity 46818202 Supplemental No

850.4550 Cyanobacteria (None) (N/A) No Data have not been submitted to fulfill this guideline. A data gap was
not identified as these data are not necessary for risk assessment at this
time.

1 This is a 42

- day study with Hyallela azteca and a 56

- day study with Chironomus dilutus or C. tentans. Both are found
in Second Edition EPA/600/R

- 99/064, Duluth, MN.

2 This is a 28

- day study conducted with the Amphipod Leptocheirus plumulosa found in First Edition, EPA Report
600/R

- 01/020, March 200 1.Page 24 of 38



### Table 8 . Available ecological effects data for terrestrial organisms exposed to imazalil and remaining data gaps.

OCSPP
Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Are data

needed for
risk
assessment? Current Additional Data
Need

850.2100 Avian oral

toxicity 163243 Acceptable Yes Requesting acute oral for passerine species

850.2200 Avian dietary

toxicity 30542 Acceptable No

--

30543 Acceptable

850.2300 Avian

reproduction 41663801 Acceptable No

42039801 Acceptable

Non

guideline Avian inhalation (None) (N/A) No Data have not been
submitted to fulfill this guideline. A data gap was
not identified as these data are not necessary for risk
assessment at this time.

850.3020 Honey bee acute

contact toxicity (None) (N/A) Yes Given that the chemical is a systemic compound, it
will be available to bees through contact and consumption of the growing plant and pollen. Data requirement may be satisfied pending completion of review (MRID 49215902).

850.3030 Honey bee residue

on foliage (None) (N/A) No Data have not been
submitted to fulfill this guideline. A data gap was
not identified as these data are not necessary for risk
assessment at this time.

850.3040 Field testing for

pollinators (None) ( N/A) No Data have not been
submitted to fulfill this guideline. A data gap was
not identified as these data are not necessary for risk
assessment at this time.

850.3100 Earthworm

Subchronic Toxicity Test (None) (N/A) Yes Given that the chemical is applied as treated seed, it will be available not only through consumption of
and contact with the seed and growing plant, as well as consumption of and
contact with the surrounding soil. Data requirement may be satisfied pendin g completion of review (MRID 49215905 ).Page 25 of 38 OCSPP
Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Are data

needed for
risk
assessment? Current Additional Data
Need

850.4100 Seedling

Emergence and Seedling Growth (None) (N/A) No Data have not been
submitted to fulfill this guideline. A data gap was
not identified as these data are not necessary for risk
assessment at this time.

850.4150 Vegetative Vigor (None) (N/A) No Data have not been
submitted to fulfill this guideline. A data gap was
not identified as these data are not necessary for risk
assessment at this time.

Non

guideline Honey bee acute

oral toxicity (None) (N/A) Yes Given that the chemical is a systemic compound, it
will be available to bees through contact and consumption of the growing plant and pollen. Data requirement may be satisfied pending completion of review (MRID 49215903 ).Page 26 of 38



## 12 . References

Internal Office of Pesticide Program Documents

D266173. Lee, Richard Larry Liu, and James Breithaupt. 2001. Revised Environmental Risk Assessment for the Reregistration of Imazalil. Internal EPA Memorandum to Mark Howaed, dated April 18, 2001.

D174917. Belew , Carol. 1992 . Proposed Section 18 for Use on Barley in Utah. Internal EPA document dated April 9, 1992. EFED # 2067901.

Environmental Fate Data Submitted To Support Registration

Goodwine, W. R. 1987. On the Equivalence in Environmental Behaviour of Imazalil and
Its Salts. Letter from W. R. Goodwine, Jansen Pharmaceutica to Herbert Manning, date March 26, 1987.

MRID 00055360. Peeters, J. 1980. R 23979: Hydrolysis Study in Acid, Neutral and
Alkaline Medium: F.C. 79

- 85 Addendum . Unpublished study received Jan 8, 1981. Submitted by Janssen R&D, Inc., New Brunswick, N.J.

MRID 00088226. Meuldermans, W., F. Knaops, E. Swysen, J. Hendrickx, and J. Heykants.
1981. Stabi l ity of t h e triti um

- label o f ima zalil

- 3 in acidic, a1 kal i ne, neutral and bio1ogi cal medium . Janssen Pharmaceuti ca, N.V., Belgium.

MRID 00096422. Torfs, F., and J. Peeters.1980. R 23979: Light Stability in Aqueous
Solution: FC 80

- 86. Unpublished study received Feb 24, 1982. Prepared by Janssen Pharmaceutica, Belgium. Sub

- mitted by Janssen R & D, Inc., New Brunswick, N.J.

MRID 00096423. Scherpenisse, P.M.; K. D. Joustra, A. J. M. Borst, et al. , 1979. An Attempt To Identify the Main Metabolite of Imazalil in Soil: Report Nr.
56635/49/1979. Unpublished study rec eived Feb 24, 1982. Prepared by Philips

Duphar B.V., The Netherlands, Submitted by Janssen R & D, Inc., New Brunswick,

N.J.

MRID 00096425. Balk, W., and A. G. M. Willems. 1979. Leaching of Imazalil and Its Metabolites: Report Nr. 56635/58/1979/WB/ybz. Unp ublished study received Feb 24, 1982. Prepared by Philips

- Duphar B.V., The Netherlands. Submitted by Janssen R & D, Inc., New Brunswick, N.J.

MRID 00022923. Hill, E.F.; Heath, R.G.; Spann, J.W.; et al. 1975. Lethal Dietary
Toxicities of Environmental Pol lutants to Birds: Special Scientific Report

-- Wildlife No. 191. U.S. Dept. of the Interior, Fish and Wildlife Service, Patuxent Wildlife Research Center; unpublished report).Page 27 of 38



### MRID 00096427. Organisch Chemisch Instituut TNO. 1977. Degradation of Imazalil in Soil under Field Conditions (Including Residue Data of Harvested Barley Grains): Report of Project 5, Part 3. Unpublished study received Feb 24, 1982.Submitted by Janssen R & D, Inc., New Brunswick, N.J.

MRID 00148072. Van Leemput, L. E. Swysen, W. Meuld ermans, et al. 1985. On the Lea

ching of Imazalil and Its Transformation Products in Soil. Unpublished study prepared by Janssen Pharmaceutica. 20 p.

MRID 00148314. Van Leemput, L. 1984. The Transformation of [Carbon

- 14]

- imazalil in
Watervliet Loam, Incubated at 25 [degrees] C in Flow

- through Soil Metabolism Systems: Serial No. R 23 979/L8. Unpublished study prepared by Janssen Pharmaceutica. 33 p.

MRID 00115272. Van Leemput, L., and J. Heykants. 1982. Hydrolysis as a Possible Mechanism of Di ssipation of Imazalil from Aqueous Environments: R 23 979/LI. Unpublished study received Oct 8, 1982. Submitted by Janssen R & D Inc., New Brunswick, NJ.

MRID 00158560. Janssen Pharmaceutica. 1986. Janssen Response [to EPA Deficiency

Letters in re Environ mental Fate of Fecundal]. Unpublished study. 55 p.

MRID 40926701. Van Leemput, L., E. Swysen, J. Hendrickx, et al . 1988. On the Photolysis of Imazalil (R23979) in the Aquatic Environment. Artificial Sunlight Experiments: Project ID. A8 1988. Unpublished s tudy prepared by Janssen Pharmaceutica. 87 p.

MRID 41350801. Van Leemput, L., E. Swysen, J. Hendrickx, et al . 1988. On the Photolysis of Imazalil (R23979) in the Aquatic Environment. Artificial Sunlight Experiments: Project ID. A8 1988. Unpublished study prepared by Janssen Pharmaceutica. 87 p. (same as MRID 40926701)

.

MRID 42012004. Sterkins, P. 1991. Anaerobic Aquatic Transformation of Imazalil: Lab Project Number: R 23979/ENV76 . Unpublished study prepared by Janssen Research Foundation. 146 p.

MRID 92072015. Goodwine, W. 1990. Janssen Pharmaceutic a Phase 3 Summary of MRID 40926701 and Related MRIDs 41350801. On the Photolysis of Imazalil (R23979) in the Aquatic Environment: Artificial Sunlight Experiments: Report No. R23979/L25, Rec #317 . Prepa red by Janssen Pharmaceutica. 29 p.

MRID 92072016. Van Leemput, L. 1990. Janssen Pharmaceutic Phase 3 Summary of MRID 00148072. On the Leaching of Imazalil (R23979) and Its Transformation Products in Soil: Report No. R23979/L11, Rec #138 . Prepared by Janssen Pharmaceutica. 19 p.Page 28 of 38



### MRID 92072017. Goodwine, W. 1990. Janssen Pharmaceutic Phase 3 Summary of MRID 00158160. Adsorption of Imazalil (R23979) on Soil: Report No. R23979/L18, February, 1986. Prepared by Janssen Pharmaceutica. 27 p.

M RID 92072034. Goodwine, W. 1990. Janssen Pharmaceutica Phase 3 Summary of MRID 00148314 and Related MRIDs 00148314, 00158160. The Transformation of [Carbon

- 14| Imazalil in Watervliet Loam, Incubated at 25 Degrees C in Flow

through Soil Metabolism Systems: Report No. R23979/L8, Rec #133. Prepared by Janssen Pharmaceutica. 32 p.

49215907 Schafers, C. (2011) Simulation Test

- Aerobic Sewage Treatment Biodegradability of Imazalil in Activated Sludge Units. Project Number: GAB/031/3/40 ENI/10/PREC/02. Unpublish ed study prepared by Fraunhofer Institute for Molecular Biology & Applied Ecology. 190p.

Ecological Toxicity Data Submitted To Support Registration:

MRID 00030542. Beavers, J.B.; Fink, R.; Brown, R.; et al. (1979) Final Report: Eight

Day Dietary LC50

-- M allard Duck: Project No. 168

- 102. (Un

- published study received Mar 7, 1980 under 43813

- 1; prepared by Wildlife International, Ltd. in cooperation with Washington College, submitted by Janssen R & D, Inc., New Brunswick, N.J.; CDL:099290

- E)

MRID 0003054 3. Beavers, J.B.; Fink, R.; Brown, R.; et al. (1979) Final Report: Eight

Day Dietary LC50

-- Bobwhite Quail: Project No. 168

- 101. (Unpublished study received Mar 7, 1980 under 43813

- 1; prepared by Wildlife International, Ltd. in cooperation with Washington College, submitted by Janssen R & D, Inc., New Brunswick, N.J.; CDL:099290

- F)

MRID 00163243. Van Ravestyn, C.; Marsboom, R. (1985) Acute Oral Toxicity Study in Ring

- necked Pheasants: Imazalil

-- R 23979: Experiment No. 1601 (86.03.10). Unpublished study prepared by Janssen Pharmaceutica N.V., Dept. of Toxicology. 18 p.

MRID 41606101. Weytjens, D.; Boonen, P.; Leemput, L. et al. (1988) The Acute Toxicity of Imazalil (R 23979) for the Bluegill ( Lepomis macrochirus ): Lab Project Number: R23979/AF/LM/6. U npublished study prepared by Janssen Pharmaceutica. 88 p.

MRID 41606102. Weytjens, D.; Boonen, P.; Callens, V. et al. (1989) The Acute Toxicity of Imazalil (R 23979) for the Rainbow Trout ( Salmo gairdneri ): Lab Project Number: R23979/AF/SG. Unpublished study pre

- pared by Janseen Pharmaceutica. 52 p.Page 29 of 38



### MRID 41606103. Weytjens, D.; Wils, R. (1990) The Acute Toxicity of Imazalil (R 239 79) in the Water

- flea ( Daphnia magna ): Lab Project Number: 23979/AD/K6

. Unpublished study prepared by Janssen Pharmaceu

- tica. 89 p.

MRID 41663801. VanCauteren, H.; Coussement, W.; Teuns, G.; et al. (1988) Reproduction Study in Bobwhite Quails: Imazalil: Nonclinical Laboratory Study: Lab Project Number: 1822. Unpublish ed study prepared by Jassen Pharmaceutica N. V. 147 p.

MRID 42039801. Teuns, G.; Lampo, A.; Coussement, W.; et al. (1991) R 23979

- Imazalil: Reproduction Study in Mallard Ducks: Report No. 2288: Rec No. 498. Unpublished study prepared by Janssen Resea rch Foundation. 321 p.

MRID 46818201. Vinken, R.; Wydra, V. (2006) Toxicity of ZR023979 Technical to the Aquatic Plant Lemna gibba in a Semi

- Static Growth Inhibition Test. Project Number: AGR/1267, 27021240. Unpublished study prepared by Institut fue r Biologische Analytik und Consulting IBACON. 93 p.

MRID 46818202. Van Ginneken, I. (1996) The Effect of Imazalil (R023979) on the Growth of the Unicellular Green Alga Selenastrum capricornutum : Final Report. Project Number: AASC/0034, ENV419, ENV/AR/0 02. Unpublished study prepared by Janssen Pharmaceutica. 90 p.

MRID 49215902 Hamon, N.; Lacy, J.; Twinn, C. (1986) Imazalil: Laboratory Determination of Direct Contract Toxicity to Adult Honeybees, Apis Mellifera L. by Potter Tower Application. Project Number: AGR/NH/JL/DCT/213/1. Unpublished study prepared by May & Baker, Ltd. 8p.

MRID 49106401. Teigeler, M. (2012) Imazalil: A Short term reproduction assay with the Zebrafish ( Danio rerio ) under flow through conditions. Project Number: CER

001/4

- 68/A. Unpublished study prepared by Fraunhofer Institute for Molecular Biology and Applied Ecology (IME). 131 p.

MRID 49215903 Lacy, J.; Hamon, N.; Twinn, C. (1986) Imazalil: Laboratory Determination of Ingestion Toxicity to Adult Honeybees, Apis mellifera L. Project Number: AGR/JL/NH/DCT/207/1. Unpublished study prepared by May & Baker, Ltd. 11p.

MRID 49215904 Leemput, L.;Swysen, E.;Meuldermans, W.;et al. (1986) The Toxicity of Imazalil ot Earthworms. Toxicity of Imazalil Sulphate to Eisenia foetida in a n Artificial Soil Toxicity Test. Project Number: R/23/979/L20. Unpublished study prepared by Janssen Pharmaceutica. 15p

MRID 49215905 Leemput, L.;Swysen, E.;Meuldermans, W.;et al. (1986) The Toxicity of Imazalil to Earthworms. Toxicity of Imazalil Sulphat e to Eisenia foetida in anPage 30 of 38 

### Artificial Soil Toxicity Test. Project Number: R/23/979/L19. Unpublished study prepared by Janssen Pharmaceutica. 16p.

MRID 49215906 Wyness, L. (1996) Imazalil: Chronic Sediment Toxicity Test Using and
Infaunal Insect Chironomu s riparius: Final Report. Project Number: 1073/2/1018. Unpublished study prepared by Corning Hazleton (Europe). 108p.Page 31 of 38



## Appendix A. Screening Ground Water Exposure Assessment Using PRZM GW

This assessment was conducted as a screen to determine whether additional data was needed for assessing exposure from ground

- water source drinking water as estimated using

PRZM

- GW. Estimates of concentrations in ground water were estimated for all 6 PRZM

G W scenarios using the application rate for wheat. The scenarios were used as is rather than adjusted to represent wheat culture as these calculations were not meant to be used for exposure assessment but only as a guide to additional data needs. The six sc enarios
simulated and their characteristics are listed in Table A

- 1.

Table A

- 1 . Scenarios used for PRZM

- GW Simulations.

Location Scenario Date Soil Weather Station (ID)

Delmarva Delmarva_STD 12/27/2012 Evesboro loamy
sand Wilmington, DE

(13781)

FL citrus FLCitrus_STD 12/18/2012 Candler, Tavares
& Astatulas soils Tampa, FL (12842)

Fl potato FLPotato_STD 12/20/2012 Pomona fine sand Jacksonville, FL (13889) Coastal Georgia GACoastal_STD Tifton loamy sand Tallahassee, FL (93805)
Coastal North
Carolina NC

Coastal_STD 12/20/2012 Norfolk loamy

s and Raleigh/Durham, NC

(13722) Central Sands,
Wisconsin WISands_STD 12/20/2012 Coloma loamy
sand La Crosse, WI

(W14920)



### All simulations assessed the seed treatment uses of imazalil. Since the label appl ication rate is the amount applied to a pound of seed, the amount of imazalil applied to a field depends on the seeding rate. The maximum seeding rate amongst the three registered crops
is for wheat which can be seeded at 156 lb∙acre

- 1 

### . With an application rate to seed of 0.0001 pounds ai of imazalil per pound of seed, the resulting field application rate of imazalil of
0.0156 lb ai∙acre

- 1 

### or 0.0175 kg∙ha

- 1 

### . The application date was set to the planting date, which is typically 14 days before the emergence d ate for wheat. The application was made using assuming a surface application as only surface and foliar applications are allowed in
the PRZM

- GW shell. Generally, applications made with seed treatments would be made below the surface with the planted seed.Page 32 of 38



### Table A

- 2. Pesticide management practices import parameters for PRZM

- GW used for
each simulation of imazalil use on wheat.
Location App. Rate

kg∙ha

- 1 

### Number of

Apps Application

Interval (days) First App

Date Application

method

Delmarva 

### 0.0175 1 NA 3/28 surface

FL citrus 

### 0.0175 1 NA 3/15 surface
Fl potato 

### 0.0175 1 NA 3/15 surface

Coastal G A 

### 0.0175 1 NA surface

Coastal N C 

### 0.0175 1 NA surface
Central Sands,

WI 

### 0.0175 1 NA 4/15 surface

The lowest measured K d 

### for imazalil was used for this assessment as it is conservative. For exposure assessments, the partition coefficient would likely be estimated as a function of pH. The hydrolysis rate was assumed to 0 as there is no observable degradation in the hydrolysis study. The aerobic soil metabolism rate was set to 3x the value for parent plus unidentified residues from the single measured rate for this compound. The factor of 3 is intended to represent an upper 90% confidence bound on the mean when only a single value is avail able and a standard deviation cannot be
calculated.
Table A

- 3. Chemistry Input Parameters for PRZM

– GW for Imazalil

. Input Parameter Value Comment hydrolysis half

- life 0 d no measureable degradation

aerobic soil metabolism 1401d 3x single value, parent plus
unidentified residues soil water partition coefficient (K d 

### ) 28 L∙kg

- 1 

### lowest K d



### The results of the simulations are in Table A

- 4. Since all the estimated values are well below previously estimate concentrations in drinking water (7.2 x 10

- 2 

### μg∙L

- 1 

### in surface waters, these levels are not expected to generate risk concerns for human health and additional data will not be required to support ground water exposure assessments for
imazalil.

Table A

- 4. Peak GW EECs for different ground water scenarios

. Location Peak EEC Mean EEC Breakthrough Time
Delmarva 1.58 x 10

- 6 μ g ∙ L

- 1 

### 1.45x 10

- 7 

### μg∙L

- 1 

### 11 y

FL citrus 5.65 x 10

- 3 

### μg∙L

- 1 

### 9.18 x 10

- 3 

### μg∙L

- 1 

### 2 y 9 mo FL potato 2.37 x 10

- 2 

### μg∙L

- 1 

### 3.71 x 10

- 4 

### μg∙L

- 1 

### 3 y 0 mo
Coastal GA 6.93 x 10

- 10 

### μg∙L

- 1 

### 3.81 x 10

- 11 

### μg∙L

- 1 

### 27 y 6 mo
Coastal NC 1.03 x 10

- 7 

### μg∙L

- 1 

### 9.01 x 10

- 10 

### μg∙L

- 1 

### 13 y 6 mo
WI sands 1.36 x 10

- 19 

### μg∙L

- 1 

### 5.3 x 10

- 21 

### μg∙L

- 1 

### 87 y 7 moPage 33 of 38



## Appendix B. Screening Level Models to Evaluate Potential Importance of Drinking Water and Inhalation Exposure Pathways

SIP ( Screening Imbibition Program, v1.0) Inputs and Conclusions

Table 1. Inputs

Parameter Value

Chemical name imazalil

Solubility (in water at 25 o C; mg/L) 180

Mammalian LD 50 (mg/kg

- bw) 343
Mammalian test species laboratory rat
Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg

- bw) 15
Mammalian test species laboratory rat
Body weight (g) of "other" mammalian species

Avian LD 50 (mg/kg

- bw) 1912

Avian test species other
Body weight (g) of "other" avian species 1000
Mineau scaling factor 1.15

Mallard NOAEC (mg/kg

- diet) 250
Bobwhite quail NOAEC (mg/kg

- diet) 250

Table 2. Mammalian Results

Parameter Acute Chronic
Upper bound exposure (mg/kg

- bw) 30.9600 30.9600
Adjusted toxicity value (mg/kg

- bw) 263.8221 11.5374
Ratio of exposure to toxicity 0.1174 2.6834

Conclusion* Exposure through drinking water alone is a potential concern for

mammals Exposure through drinking water

alone is a potential concern for

mammals

Table 3. Avian Results

Parameter Acute Chronic
Upper bound exposure (mg/kg

- bw) 145.8000 145.8000
Adjusted toxicity value (mg/kg

- bw) 1063.2671 12.4031
Ratio of exposure to acute toxicity 0.1371 11.7551

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 animals.Page 34 of 38



### STIR ( S creening T

ool for I nhalation R isk, v1.0) Inputs and Conclusions

Input Value Conclusion

Application and Chemical Information

Enter Chemical Name imazalil

Enter Chemical Use seed treatment
Is the Application a Spray? (enter y or n) n If Spray What Type (enter ground or air) ground
Enter Chemical Molecular Weight (g/mole) 297.2
Enter Chemical Vapor Pressure (mmHg) 1.20E

- 06
Enter Application Rate (lb a.i./acre) 0.0156

Toxicity Properties

Bird

Enter Lowest Bird Oral LD 50 (mg/kg bw) 1912

Enter Mineau Scaling Factor 1.15
Enter Tested Bird Weight (kg) 1

Mammal

Enter Lowest Rat Oral LD 50 (mg/kg bw) 343

Enter Lowest Rat Inhalation LC 50 (mg/L) 2.43
Duration of Rat Inhalation Study (hrs) 4
Enter Rat Weight (kg) 0.35

Output

Results Avian (0.020 kg )

Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 1.92E

- 02

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 2.41E

- 03

Adjusted Inhalation LD 50 5.83E+01

Ratio of Vapor Dose to Adjusted Inhalation LD 50 4.14E

- 05 Exposure not Likely Significant

Maximum Post

- treatment Spray Inhalation Dose (mg/kg) not applicable

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 not applicable not applicable

Results Mammalian (0.015 kg )

Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 1.92E

- 02

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 3.03E

- 03

Adjusted Inhalation LD 50 1.45E+02

Ratio of Vapor Dose to Adjusted Inhalation LD 50 2.10E

- 05 Exposure not Likely Significant

Maximum Post

- treatment Spray Inhalation Dose (mg/kg) not applicable

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 not applicable not applicablePage 35 of 38



## Appendix C. Data Justification Tables for Chronic Sediment Toxicity Studies

No chronic whole sediment toxicity data for freshwater or saltwater invertebrates are available. 40 CFR 158 conditionally requires whole sediment chronic toxicity data for freshwater and estuarine/marine
invertebrates. Whole sediment chronic to xicity data would be useful to risk assessment because the log

K OW of imazalil is ≥3. Current EFED recommendations for freshwater sediment testing follow Agency

wide guidance stated in Test Method 100.4:

“ Hyalella azteca 42

- d Test for Measuring the Effects of Sediment Associated Contaminants on Survival, Growth, and Reproduction” contained in USEPA 2000 Methods for Measuring the Toxicity and Bioaccumulation of Sediment

- associated Contaminants with Freshwater
Invertebrates EPA 600/R

- 99/064 (OCSPP 850.1770)

.

A protocol should be submitted for approval prior to testing. Based on test variability for the endpoints of concern and the need to establish a NOAEC/LOAEC the following number of replicates and test animals

are rec ommended for the freshwater amphipod H. azteca :

 12 replicates per treatment (4 for 28

- d survival and growth and 8 for the remainder of the test) with 10 neonates per replicate.

In the absence of data, toxicity will be estimated using the lowest chronic t oxicity endpoint for freshwater invertebrates and the estimated pore water concentrations in sediment. This does not consider possible exposure via ingestion and could underestimate risk for some invertebrates where ingestion is an important exposure path way; therefore, there will be considerable uncertainty in risk conclusions.

The requested data would allow EPA to estimate chronic risks to benthic invertebrates, including defining an effect area for endangered species. Risk mitigation strategies ( e.g

. , determining the maximum imazalil application rate that results in a Risk Quotient (RQ) below the Level of Concern (LOC) cannot be
evaluated without these data.

Imazalil is likely to partition to soil and sediment and may enter water via soil erosion and via waste water from citrus packing plants. Given the lack of chronic aquatic data, the high K
ow of imazalil and an aerobic
soil metabolism half

- life of 157 days, these data would be useful to the risk assessment.

Practical Utility of the Data
How will the data be used? The data would allow the Agency to determine chronic risk to benthic freshwater invertebrates from
imazalil in water and sediment. The effects data would be used to determine the likelihood that the chronic risks can potentiall y impact aquatic communities, either by direct effects or by indirect effects on other organisms by reducing their food sources.

How could the data impact the Agency’s future decision

- making? Risk assessment and mitigation strategies ( e.g. , determinin g the maximum imazalil application rate that results in RQs below the LOC) cannot be evaluated without these data. If future endangered species risk assessments are performed without these data, the Agency would have to assume that imazalil “may Guideline Number: Non

- Guideline study (850 Method not yet available) Use Test Method 100.4 (citation included in text). Study Title: Whole Sediment: Chronic Toxicity to Freshwater Invertebrate

- Examining Survival, Growth, and Reproduction for Hyaella azteca

. Test Chemical: Imazalil Rationale for Requiring the DataPage 36 of 38

affect” e ndangered freshwater invertebrates directly (and endangered species from other taxa indirectly), and use of imazalil might need to be restricted in areas where endangered species could be exposed. The lack of these data will limit the flexibility the Agen cy and registrants have in coming into compliance with the Endangered Species Act and could result in use restrictions for imazalil which are unnecessarily

severe.

No chronic whole sediment toxicity data for freshwater or saltwater invertebrates are available. 40 CFR 158 conditionally requires whole sediment chronic toxicity data for freshwater and estuarine/marine invertebrates. Whole sediment chronic toxicity data w ould be useful to risk assessment because the log

K OW of imazalil is ≥3. Current EFED recommendations for freshwater sediment testing follow Agency

wide guidance stated in Test Method 100.5:
“Life

- cycle Test for Measuring the Effects of Sediment

- associated Contaminants on Chironomus
dilutus or C. tentans ” contained in USEPA 2000 Methods for Measuring the Toxicity and
Bioaccumulation of Sediment

- associated Contaminants with Freshwater Invertebr ates EPA 600/R

99/064 (OCSPP 850.1760)

.

A protocol should be submitted for approval prior to testing. Based on test variability for the endpoints of concern and the need to establish a NOAEC/LOAEC the following number of replicates and test animals

are recommended for the midge test with C. dilutus or C. tentans :

 16 replicates per treatment containing 12 test organisms each (12 replicates at test initiation; 4 added at 10 days for auxiliary males).

In the absence of data, toxicity will be estimated u sing the lowest chronic toxicity endpoint for freshwater invertebrates and the estimated pore water concentrations in sediment. This does not consider possible exposure via ingestion and could underestimate risk for some invertebrates where ingestion is a n important exposure pathway; therefore, there will be considerable uncertainty in risk conclusions.

The requested data would allow EPA to estimate chronic risks to benthic invertebrates, including defining an effect area for endangered species. Risk mit igation strategies ( e.g

. , determining the maximum imazalil application rate that results in a Risk Quotient (RQ) below the Level of Concern (LOC) cannot be
evaluated without these data.

Imazalil is likely to partition to soil and sediment and may enter water via soil erosion and via waste water from citrus packing plants. Given the lack of chronic aquatic data, the high K
ow of imazalil and an aerobic
soil metabolism half

- life of 157 days, these data would be useful to the risk assessment.

Practical Utility of the Data
How will the data be used? The data would allow the Agency to determine chronic risk to benthic freshwater and estuarine/marine
invertebrates from imazalil in water and sediment. The effects data would be used to determine the likelihood that the chronic risks can potentially impact aquatic communities, either by direct effects or by indirect effects on other organisms by reducing their food sources.

How could the data impact the Agency’s future decision

- making? Guideline Number: Non

- Guideline study (850 Method not yet available) Use Test Method 100. 5 (citation included in text). Study Title: Whole Sediment: Chronic Toxicity to Freshwater Invertebrates

- Examining Survival, Growth, and Reproduction for Chironomus dilutus or C. tentans

. Test Chemical: Imazalil. Rationale for Requiring the DataPage 37 of 38

Risk assessment and mitigation strategies ( e.g. , determining the maximum imazalil application rate that results in RQs below the LOC) cannot be evaluated without these data. If future endangere d species risk assessments are performed without these data, the Agency would have to assume that imazalil “may affect” endangered freshwater invertebrates directly (and endangered species from other taxa indirectly), and use of imazalil might need to be r estricted in areas where endangered species could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act and could result in use restrictions for imazalil whi ch are unnecessarily

severe.

No chronic whole sediment toxicity data for saltwater invertebrates are available. 40 CFR 158 conditionally requires whole sediment chronic toxicity data for freshwater and estuarine/marine invertebrates. Whole sediment chronic toxicity data for saltwater invertebrates would be useful to risk assessment because the log K OW of imazalil is ≥3. Current EFED recommendations for freshwater sediment testing follow Agency

- wide guidance stated in: “Method for Assessing the Chronic Toxicity of Marine and Estuarine Sediment

- associated Contaminants with the Amphipod Leptocheirus plumulosus EPA 600/R

- 01/020 (OCSPP 850.1780).

A protocol should be submitted for approval prior to testing. In the absence of data, toxicity will be estimated using the lowest chronic toxicity endpoint for saltwater invertebrates and the estimated pore water concentrations in sediment. This does not consider possible exposure via ingestion and could

u nderestimate risk for some invertebrates where ingestion is an important exposure pathway; therefore, there will be considerable uncertainty in risk conclusions.

The requested data would allow EPA to estimate chronic risks to benthic invertebrates, includ ing defining an effect area for endangered species. Risk mitigation strategies ( e.g

. , determining the maximum imazalil application rate that results in a Risk Quotient (RQ) below the Level of Concern (LOC) cannot be
evaluated without these data.

Imazalil is likely to partition to soil and sediment and may enter water via soil erosion and via waste water from citrus packing plants. Given the lack of chronic aquatic data, the high K
ow of imazalil and an aerobic
soil metabolism half

- life of 157 days, these data would be useful to the risk assessment.

Practical Utility of the Data

How will the data be used? The data would allow the Agency to determine chronic risk to benthic estuarine/marine invertebrates from
imazalil in water and sediment. The effects data would be used to determine the likelihood that the chronic risks can potentially impact aquatic communities, either by direct effects or by indirect effects on other organisms by reducing their food sources.

How could the data impact the Agency’s future decision

- making? Risk assessment and mitigation strategies ( e.g. , determining the maximum imazalil application rate that results in RQs below the LOC) cannot be evaluated without these data. If future endangere d species risk Guideline Number: Non

- Guideline study (850 Method not yet available) Use Citation included in

text. Study Title: Whole Sediment: Chronic Toxicity to Saltwater Invertebrates

- Examining Survival, Growth, and Reproduction for Leptocheirus plumulosus

. Test Chemical: Imazalil Rationale for Requiring the DataPage 38 of 38

assessments are performed without these data, the Agency would have to assume that imazalil “may affect” endangered saltwater invertebrates directly (and endangered species from other taxa indirectly), and use of imazalil might need to be re stricted in areas where endangered species could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act and could result in use restrictions for imazalil whic h are unnecessarily

severe.