UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

JUL se zoa 

' 

MEMORANDUM 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

SUBJECT: BEAD Chemical Profile for Registration Review: lmazalil (111901) and Imazalil 

Sulfate (111902) 

FROM: Tara Chandgoyal, Ph. D., Plant Pathologist 

Biological Analysis Branch 

/'}." , Cynthia Doucoure, Environmental Protection Specialist L: ~ 

THRU: 

Science Information and Analysis Branch 

Andrew Lee, Economist 01 (· _} Economic 

Biological 

Analysis 

and Economic 

Branch 

Analysis Division (7503P) 

~ 

ArnetJones, Chief /:J .. ~AJ Biological Analysis Branch ~ Y ( 

Diann 

Science 

Sims, 

Information 

Chief )..[)c:z and Analysis ~ Branch 

Timothy Kiely, Chief .-,c} ~ H {t ~ (6~t...'~ Z6 J,, 1.. ]Dt~ Economic Analysis Branch r . I -v<! 

Biological and Economic Analysis Division (7503P) 

TO: Margaret Hathaway, Chemical Review Manager 

Risk Management and Implementation Branch 2 

Pesticide Reevaluation Division (7508P) 

Product Review Panel date: June 19, 2013 

Page 1 of10 
INTRODUCTION 

The purpose of this document is to convey usage information and a broad overview of the pest 

management roles of pesticides that are beginning to undergo registration review. The 

anticipated audience consists of the team of EPA staff currently evaluating the registration status 

of imazalil, and eventually the general public. This document builds upon the data BEAD 

provides in the Label Use Information System (LUIS) reports and the Screening Level Usage 

Analysis (SLUA) to Registration Review teams. The document is based on information and 

data available to BEAD as of May 2013. 

Imazalil is a systemic fungicide that was registered in the U.S. in 1983. lmazalil sulfate was 

registered in March. 2004. Imazalil and imazalil sulfate are systemic fungicides used for the 

control of fungal pathogens on postharvest citrus fruits and on wheat, barley and triticale. 

Imazalil is also used in chicken hatcheries for the control of poultry aspergillosis (caused by 

Aspergillusfumigatus). Resistance in many fungal pests has been reported and FRAC (2013) 

recommends resistance management. Imazalil sulfate is effective against fungal pests on citrus 

fruits. The "Report of FQPA Tolerance Reassessment Progress and Interim Risk Management 

Decision (TRED) for Imazalil" was completed on July 12, 2002. The Imazalil Reregistration 

Eligibility Decision (RED) was approved on February 25, 2005 and amended March 16, 2005. 

HISTORY OF BEAD ASSESSMENTS FOR IMAZALIL 

There are no BEAD assessments for this chemical that are relevant to the current registration 

review work. 

COMMON FORMULATIONS AND APPLICATION METHODS 

Imazalil is commonly formulated as a liquid ready-to-use, pressurized liquid, emulsifiable 

concentrate, water soluble granule, and smoke candles. Imazalil is applied as a seed treatment 

using mist-type equipment and mechanical slurries. Imazalil is also applied as a postharvest 

treatment using a foarner, spray brush, dips, wash tanks, wax and drenches. In chicken 

hatcheries, imazalil is applied using a smoke candle treatment to disinfect equipment (empty 

hatchery cabinets, setters, coolers, storerooms, and egg handling equipment) prior to the 

introduction of the eggs. 

Imazalil sulfate is commonly formulated as a soluble powder, water soluble granule, and a 

flowable concentrate and applied as a postharvest treatment using dip and wash tanks, drenchers, 

and in aqueous line and storage wax line spray applications, as well as in non-recovery spray and 

water spray brush applications. 

Page 2 of 10 
USE SITES 

Agricultural Use Sites: 

Imazalil is registered alone for postharvest use on citrus and alone or in combination with 

metalaxyl, tebuconazole, and/or imidacloprid for preplant use on wheat, barley, and triticale 

seeds. 

Imazalil sulfate is registered alone or in combination with pyrimethanil for postharvest use on the 

citrus fruit crop group including calamondin, citrus citron, grapefruit, kumquat, lemon, lime, 

mandarin, orange (sweet & sour), pummel, and Satsuma mandarin. 

Non-Agricultural Use Sites: 

Imazalil is registered for use as a chicken hatchery treatment, and in commercial greenhouses on 

ornamentals, bedding plants, cut flowers, flowering hanging baskets, foliage, potted flowering 

plants, and perennials. There are no non-agricultural uses registered for imazalil sulfate 

IMAZALIL & IMAZALIL SULFATE USAGE 

BEAD reviewed available data sources for reported use of imazalil on wheat, barley, postharvest 

citrus, and other agricultural and non-agricultural uses and for reported use of imazalil sulfate on 

postharvest citrus since approval of the RED in February 2005. BEAD found usage information 

that far exceeds estimates in the RED for wheat from private market research surveys and for 

postharvest citrus and other uses as reported in California Department of Pesticide Regulation 

(DPR) and shown in the sections below. 

Imazalil Wheat Seed Treatments 

BEAD found available proprietary data based on private market research data for wheat seed 

treatment for the years 2009-2011. The vendor of the proprietary data did not conduct surveys 

on the use of fungicide as seed treatments until 2009. During the 2009-2011 period, imazalil 

usage, in terms of pounds of active ingredient (a.i.) applied to wheat seeds and the total area 

treated (TAT) or planted with those seeds, decreased as shown in Figures 1 and 2. 

Approximately 5,300 pounds of imazalil were applied to wheat seeds on average annually and 

planted on 2,526,000 acres at an overall average application rate of 0.002 lbs ai/acre. 

Spring wheat seed treatments, when compared to the total pounds of imazalil applied, accounted 

for 70% of the pounds a.i. applied and total area treated or planted during this period, followed 

by winter wheat seed treatments at 30%. As for the percent crop treated (PCT), spring wheat 

seed treatments accounted for 1 0% PCT while winter wheat accounted for <2.5% PCT (lmazalil 

SLUA, 2013). 

The top states in terms of pounds a.i. applied to seeds and total area treated or planted during 

this period were Montana (26%) and North Dakota (45%). Other states that reportedly use 

imazalil include the following: CA, ID, KS, MN, MO, OH, OK, OR, SD, TN, VA, and W A. 

Page 3 oflO 
Figure 1. Imazalil Wheat Seed Treatments: Pounds AI Applied, 2009-20 I I 

-a 

-~ 

a. 

a. 

ct 

< 

-a "' 

c 

:s 

0 

Q. 

6,000 

2009 2010 

Year 

Source: EPA Proprietary Data, 2009-201 1 

2011 

Wheat, Spring 

- Wheat, Winter 

Figure 2: Imazalil Wheat Seed Treatments: Total Area Treated/Planted, 2009-20 11 

-a 

Cll 

.. 

c 

1'0 

0:: 

--a Cll 

.. 

1'0 

Cll 

... 

1-

1'0 

Cll 

... 

ct 

-;; 

~ 

2,500,000 -r--------------

2009 2010 2011 

Year 

Source: EPA Proprietary Data, 2009-2011 

Page 4 oflO 

he at, Spring 

- Wheat, Winter 
Agricultural Usage on Planted Wheat Seeds by Crop Reporting District 

Another measure of usage is the use intensity. In this analysis, the use intensity is expressed as 

the pounds a.i. applied on planted wheat seeds per 1,000 acres of land in farms. This differs 

from the application rate, which is expressed as 0.002 pounds a.i. applied on seeds per treated/ 

planted area or 0.2 pounds a.i. per 1,000 acres in farmland. In contrast, the maximum observed 

use intensity is between 0.053 and 0.085 pounds per 1,000 acres in farmJand. Figure 5 spatially 

represents imazalil use intensity in the U.S. on planted wheat seeds, which is relatively greater in 

North Dakota. This reflects a high concentration of spring wheat production - Montana, North 

Dakota, and Minnesota account for approximately 80 percent of the U.S. spring wheat acreage 

(NASS, 2013) - and a higher percentage of acres of spring wheat than of winter wheat. 

Figure 3. Wheat: lmazalil Use Intensity by Crop Reporting District (2009- 2011) 

Average Pounds Per 

1,000 Acres of Farmland 

- <0.004 

- 0.004-0.006 

D o.oo1- o.o15 

- 0.016-0.052 

- 0.053- 0.085 

Sources: 

Proprietary Data. 2007-20 II. 

USDA, 2007. Census of Agriculture. Online: http://www.agcensus.usda.gov/Publications/2007/index.asp. 

Page 5 of10 
Imazalil and Imazalil Sulfate Usage in California 

BEAD reviewed available data sources for reported use of imazalil and imazalil sulfate in the 

U.S. and found recent data for citrus and other uses from California DPR for the years 2006-

201 1 as seen in Tables 1 and 2 below. California, however, ranks second in citrus production but 

dominates Florida, Texas, and Arizona in fresh citrus produce. Florida is the leading producer of 

citrus fruits, followed by Texas and Arizona. BEAD did not find any recent survey data from 

these states reporting use of imazalil and imazalil sulfate on citrus nor reporting use of imazalil 

on landscapes. As such, please note that the data below underestimates U.S. usage ofimazalil 

and imazalil sulfate on postharvest citrus. BEAD also found data in California DPR for reported 

use on "other" sites as seen in Table 1 below. 

T bl 1 I a e maza nu 1 sa lle m a . c 1'£ 1 orrua, . 2006 -2011 

Site Pounds A.I. AJ!Piied 

2006 2007 2008 2009 2010 2011 

Citrus 3,987.7 2,332.1 2,635.5 1,285.9 2,005.4 4,822.50 

(all or unspecified) 

Grapefruit 25.2 36.1 121.8 92.1 296.4 74.61 

Lemon 2,639.9 2,829.9 4,016.2 1,194.5 7,035.9 1,927.32 

Lime NA NA NA NA NA 0.06 

Oranges 14,503.8 9,074.4 16,539.0 9,909.9 14,313.2 14,744.81 

Pomelo (Shaddock) 3.4 1.8 NA NA NA NA 

Tangelo/Tangerine 66.7 58.5 85.2 66.1 326.3 520.56 

Commodity 107.8 75.4 45.5 83.7 1,173.3 79.36 

Fumigation 

Other* 289.3 6.3 51.1 1,591.8 2,368.1 3583.33 

Total 21,623.80 14,412.7 23,494.3 14,224.0 27,518.6 25,752.55 . . .. Source: CA DPR, 2006-2011, Pest1c1de Use Annual Summanes, Summary ofPesttctde Use Report Data Indexed by 

Chemical 

NA: Not Available 

*Other reported uses in California include landscape maintenance, structural pest control, wheat (forage/fodder), 

public health pest control, regulatory pest control, vertebrate pest control, animal husbandry premises, and research 

commodity. Please note that California reporting categories do not always follow the terminology of labeled use 

sites. 

Table 2 Imazalil Sulfate Usage on Postharvest Citrus in California 2006-2011 ' Site Pounds A.l. Applied 

2006 2007 2008 2009 2010 2011 

Citrus 1,787.9 487.4 683.5 395.8 724.6 2,909.38 

(all or unspecified) 

Grapefruit NA NA 2.1 5.0 2.8 2.0 

Lemon 180.8 39.7 0.3 25.3 24.0 35.1 

Oranges 756.4 219.3 524.6 171.3 676.3 401.3 

Commodity NA NA NA NA 351.9 NA 

Fumigation 

Total 937.2 746.4 1,210.5 597.4 1,779.6 3,347.78 

Page 6 of10 
Source: CA DPR, 2006-20 II , Pesticide Use Annual Summaries, Summary of Pesticide Use Report Data Indexed by 

Chemical 

NA: Not Available 

Non-Agricultural Usage in Greenhouses 

BEAD reviewed available usage data sources but did not fmd any usage information for imazalil 

use in greenhouses on ornamentals. 

BIOLOGICAL ASPECTS RELEVANT TO IMAZALIL 

Imazalil is a systemic fungicide that belongs to Fungicide Resistance Action Committee mode of 

action code 3 (FRAC, 20 13). It is considered as medium risk for resistance. It is effective against 

many fungal pests on many crops (CDMS, 2010). Resistance in many fungi has been reported 

and FRAC (20 13) recommends resistance management. The resistance can be managed by 

mixing fungicides with different modes of action or alternating them. Imazalil, imazalil sulfate, 

and imazalil sulfate + pyrimethanil are used for the postharvest control of green mold, blue mold, 

Phomopsis end rot, Diplodia rot and Alternaria rot diseases of citrus fruits. Imazalil alone or in 

combination with metalaxyl, tebuconazole, and/or imidacloprid are used for treating wheat, 

barley and triticale seed, prior to planting, for protection against fungal pests. Imazalil is also 

registered for use in chicken hatcheries to control of poultry aspergillosis (caused by Aspergillus 

fumigatus). 

ROLE OF IMAZALIL IN PEST MANAGEMENT 

Imazalil fungicide appears to be efficacious against many fungal pests of citrus fruits, wheat, 

barley, and triticale. It is a valuable fungicide for the control of fungal diseases on these crops. It 

has different mode of action than the other registered alternatives and therefore plays an 

important role in fungal pest control and pest resistance management. Available data on wheat 

show that the predominant use of imazalil is on seeds of spring wheat, which accounted for 70% 

of pounds a.i. applied and 10% PCT. Also, the recent California data appears to show that 

imazalil and imazalil sulfate are very import.ant to the postharvest citrus production in California, 

where these chemicals are used predominantly on oranges and lemons and increasingly on 

grapefruits. However, without having production data on postharvest citrus and the amount of 

the citrus commodities treated in California, Florida, Arizona, and Texas, it is difficult to 

determine the importance of imazalil and imazalil and imazalil sulfate in citrus production in the 

U.S. 

INFORMATION THAT MAY BE USEFUL FOR BEAD'S FUTURE WORK ON 

IMAZALIL 

The Agency currently does not have important information on imazalil and imazalil sulfate. 

Obtaining the following usage information may improve future assessments conducted by the 

Agency related to the use and importance of imazalil and imazalil sulfate: 

Page 7 of 10 
• Information on imazalil and imazalil sulfate as a postharvest treatment in citrus in 

California, Arizona, Florida and Texas, including pounds a.i. applied, application timing, 

application rate, application method, and application frequency. 

• Information on amount of citrus produced in California, Arizona, Florida and Texas and 

the amount of the citrus commodities treated with imazalil and imazalil sulfate. 

• Information on the use of imazalil in greenhouses to treat various ornamentals and in 

chicken hatcheries to treat egg handling equipment, including pounds a.i. applied, 

application timing, application rate, application method, and application frequency. 

REFERENCES 

California DPR, 2006-201 1, Pesticide Use Annual Summaries, Summary of Pesticide Use 

Report Data Indexed by Chemical. http://www.cdpr.ca.gov/docs/pur/purmain.htm 

CDMS. 2010. Label Search. http://prernier.cdms.net/webapls/FormsLogin.asp?/webapls/ 

Accessed May 6-9, 2013. 

EPA Proprietary Data, 2009-2011 

EPA, Imazali1 Screening Level Usage Analysis (SLUA), January 2013 

FRAC. 2013. FRAC Code List 2013: Fungicides sorted by mode of action (including FRAC 

Code numbering). http://www .frac.info/publication/anhang/FRAC%20Code%20List%2020 13-

update%20April-20 13 .pdf 

USDA, 2006-2010. NASS Crop Reporting Districts. 

http://www .ers. usda. govlbriefing/arms/resourceregions/resourceregions.htm#nass. 

USDA, 2007. Census of Agriculture. 

http://www .agcensus. usda. gov /Publications/2007 /index.asp. 

USDA NASS, March 2003, Agricultural Chemical Usage Reports. 

http://usda.mannlib.cornell.edu/MannUsdalviewDocumentinfo.do?documentiD=1571 

USDA NASS. 2013. Crop Production 2012 Summary. National Agricultural Statistics Service, 

U.S. Department of Agriculture. 

http://usdaO 1.library.cornell.edulusdalcurrent/CropProdSu!CropProdSu-0 1-11-2013 .pdf. 

Page 8 oflO 
APPENDIX A 

This is a map of agricultural pesticide usage at the Crop Reporting District (CRD) level 

prepared by BEAD for use in the Environmental Fate and Effects Division documents. 

These maps are used to help visualize where the pesticide being considered is most likely 

to be used and can be helpful in scenario selection and placing the exposure assessment in 

context. CRDs are boundaries created by USDA NASS which are aggregates of counties. 

Pesticide usage is displayed as average pounds (for the years 2007-2011) per 1,000 acres of 

farmland in a CRD to normalize for the variation in farmland between CRDs. Farmland 

acreage was obtained from USDA (2007). Farmland or "land in farms" is defined as 

follows: 

The acreage designated as "land in farms" consists primarily of 

agricultural land used for crops, pasture, or gr.azing. It also 

includes woodland and wasteland not actually under cultivation or 

used for pasture or grazing, provided it was part of the farm 

operator's total operation. Large acreages of woodland or 

wasteland held for nonagricultural purposes were deleted from 

individual reports during the edit process. Land in farms includes 

CRP, WRP, FWP, and CREP1 acres. Land in farms is an operating 

unit concept and includes land owned and operated as well as land 

rented from others. Land used rent free was reported as land rented 

from others. All grazing land, except land used under government 

permits on a per-head basis, was included as "land in farms" 

provided it was part of a farm or ranch. Land under the exclusive 

use of a grazing association was reported by the grazing 

association and included as land in farms. All land in American 

Indian reservations used for growing crops, grazing livestock, or 

the potential of grazing livestock was included as land in farms. 

Land in reservations not reported by reservation, individual 

American Indians or non-Native Americans was reported in the 

name of the cooperative group that used the land. In many 

instances, an entire American Indian reservation was reported as 

one farm (USDA, 2007). 

Usage is based on private market surveys of pesticide use in agriculture (Proprietary Data, 

2007-2011). The survey data are limited to the states that represent the top 80-90% of 

acreage for the individual crops; therefore, use may be occurring in regions outside the 

scope of the survey. CRDs showing no usage of pesticides may be due to either the lack of 

pesticide use in the region or non-participation in the agricultural surveys. In addition, 

across the years, there may be variations in the specific crops included in the CRD survey. 

This may result in a lower annual average for the CRD. 

1 CRP: Conservation Reserve Program; WRP: Wetland Reserve Program; FWP: Farmable Wetlands Program; 

CREP: Conservation Reserve Enhancement Program 

Page 9 oflO 
This map displays ratio data (i.e., average pounds per I ,000 acres of farmland) summarized 

at a very high-level. Readers are strongly cautioned against trying to over interpret the map 

without examination of the underlying data. The underlying data may explain some of the 

many reasons that a Crop Reporting District may have a high value for a particular active 

ingredient such as significant acreage (compared with the CRD as a whole) of a crop or 

crops with a high application rate and frequency of application. 

The reader should pay particular attention to the figure legends and realize that a map 

prepared for a particular chemical is not directly comparable to a map prepared for a 

different chemical. Scale and units of measurement do matter and may be different 

between maps. 

Page 10 of 10