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OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

PC Code: 288202

DP Barcode: D425914

MEMORANDUM

DATE: May 4, 2015

SUBJECT: Estimated Drinking Water Concentrations for Cyprodinil and its Metabolite 

CGA-249287 for the New Uses of the Chemical on Tree Nuts Crop Group 14-12, 

Including Filberts (Hazelnut) and Pecans

FROM: José L. Meléndez, Chemist

Environmental Risk Branch 5

Environmental Fate and Effects Division (7507P)

THROUGH: Mah T. Shamim, Ph.D., Branch Chief

Environmental Risk Branch 5

Environmental Fate and Effects Division (7507P)

TO: Heather Garvie, Risk Manager Reviewer

Hope Johnson, Product Manager #21

Cynthia Giles-Parker, Branch Chief

Fungicide Branch

Registration Division (7505P)

AND: Thurston Morton, Chemist

Elissa Reaves, Branch Chief

Risk Assessment Branch 4

Health Effects Division (7509P)

This memo presents the Estimated Drinking Water Concentrations (EDWCs) for cyprodinil, an 

active ingredient of Vangard® WG, SwitchTM 62.5G, and Inspire Super® Fungicides, and its 

metabolite CGA-249287 [as per the Metabolism Assessment Review Committee’s decision 

document (MARC)], for the new uses of the chemical on Tree Nuts Crop Group 14-12, including 

filberts (hazelnut) and pecans. Based on a review of the use information, it was found that the 

newly proposed crops have a lower application rate than the maximum application rate of 0.47 lb 

a.i./A applied three times per year, or 1.4 lb a.i./A/year, previously modeled using the California 
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almond and New York grapes scenario (note: the NY grape scenario yielded the highest surface 

waters EDWCs). EDWCs for the new uses should be similar to those already calculated for grapes. 

Since previously modeled crops cover the new proposed crops, the results of the previous drinking 

waters assessment (DWA) can be used for the new uses; a new DWA is not required.

The previous DWA dated January 12, 2015 provides EDWCs from the new model PRZM-GW, 

which had not been modeled (DP Barcode D421158). Further, a previous DWA, dated November 

8, 2010 (DP Barcode D382086), involved only the products Vangard® WG and Switch® 62.5G 

Fungicides and the request to apply a maximum of two times aerially the products to most of the 

crops, and chemigation applications for several of the crops. The DWA provides structures and 

nomenclature of cyprodinil and its metabolite CGA-249287, as well as a summary of 

environmental fate for the chemical. In a November 4, 2011 DWA, a number of new uses were 

evaluated (DP Barcode D391853), but it referred back to the 2010 DWA for EDWCs.

The tier 2 aquatic models PRZM/EXAMS, and the models SCI-GROW and PRZM-GW were used 

to obtain EDWCs in surface water and groundwater, respectively. The acute EDWC in surface 

water is 34.8 μg/L for the total residues of cyprodinil plus CGA-249287. The chronic EDWC in 

surface waters is 24.7 μg/L for the total residues of cyprodinil and CGA-249287. The 

cancer/chronic EDWC in surface waters is 16.4 μg/L for the total residues of cyprodinil and CGA249287. All surface waters EDWCs were obtained using the New York grapes PRZM scenario. 

The PRZM-GW generated EDWC for the use on grapes (using the FL citrus surrogate scenario),

were 2.05 μg/L for the total residues of cyprodinil and CGA-249287 (acute) and 1.80 μg/L for the 

total residues (chronic). For details on methods, characterization of results, uncertainties, etc., 

please, refer to the previous DWAs. Table 1 provides a summary of the Tier 2 modeled drinking 

water concentrations.

Table 1. Maximum Estimated Drinking Water Concentrations for the Use of Cyprodinil (expressed as 

total residues of cyprodinil plus its degradate CGA-249287)

DRINKING WATER SOURCE 

(MODEL USED) USE (rate modeled per year) MAXIMUM ESTIMATED DRINKING WATER 

CONCENTRATION (EDWC) ( ppb)

Groundwater (PRZM-GW) FL citrus1 (1.4 lb a.i./season) Acute 2.05

Chronic 1.80

Surface water

(PRZM/EXAMS) NY grapes (1.4 lb a.i./season)

Acute 34.8

Chronic 24.7

Cancer/Chronic 16.4

1 Scenario was used as a surrogate and run with the maximum application rate for grapes.

Should it be required, additional refinements may be available. For example, regional PCAs and 

typical use rates may be options to be used should it be requested by HED.

Identification of specific data gaps:

The environmental fate data base for cyprodinil is considered substantially complete; there are no 

new reviewed data for this assessment. There is uncertainty with the aqueous photolysis study

(MRID 43908422). It was carried out with natural (unsterilized) water. Phototransformation of 

cyprodinil in the irradiated samples followed a biphasic pattern, with slow transformation at the 

beginning. The possibility of microbial transformation is not ruled out. For modeling purposes, 

it was assumed that cyprodinil is stable to aqueous photolysis, which is a conservative assumption. 
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Since the Problem Formulation for Registration Review was issued in 2012 (DP Barcode 

D393800), soil metabolism studies were submitted, which are currently in review.

Use information:

The end-use products involved in this DWA is Inspire Super® Fungicide; however, there are 

three products that contain cyprodinil, as shown below. One product contains only cyprodinil, 

while two of the products have another active ingredient:

• Vangard® WG Fungicide (EPA Reg. No. 100-828), containing 75.0% cyprodinil A.I. and 

25.0% other ingredients

• Switch® 62.5G Fungicide (EPA Reg. No. 100-953) containing 37.5% cyprodinil A.I., 

25.0% fludioxonil A.I. and 37.5% other ingredients

• Inspire Super® Fungicide (EPA Reg. No. 100-1317) containing 24.1% cyprodinil A.I., 

8.4% difenoconazole A.I. and 67.5% other ingredients

Table 2 provides a summary of the current use information for the pesticide cyprodinil only (i.e., 

the table does not include the other two active ingredients), relative to the tree nut crop group, 

based on all previously available labels. It also shows which crop has been modeled in the past. 

Generally, no more than two sequential applications are allowed as part of a resistance 

management strategy (unless otherwise stated for a crop). The label requires a buffer zone to 

protect lakes, reservoirs, rivers, permanent streams, marshes or natural ponds, estuaries and 

commercial fish ponds. For ground applications the buffer zone is 75 ft; meanwhile, for aerial 

applications the buffer zone is 150 ft. A vegetative filter strip should be allowed within 10 ft of 

aquatic areas. Furthermore, other measures of precaution are required (e.g. applications when 

gusts or sustained winds exceed 10 mph are not allowed). Table 3 provides a summary of the 

proposed use pattern for Inspire Super® Fungicide (shaded gray). Note that almonds and 

pistachios are previously registered uses in this particular label.

Several crops have been modeled in the past, using seasonal rates of 1.4 lb a.i./A/season. These 

include CA almond, NY grape, CA fruit and MI cherry. Additionally, other crops have been 

modeled using a seasonal rate of 1.3 lb a.i./A/season, which included OR snap bean, FL strawberry, 

MO melon, NC sweet potato, GA onion and PA tomato. The new use (nut trees, including filberts 

and pecans) involves a lower rate than previously modeled for CA almond (Table 3). Since the 

previously modeled crop covers the new proposed crops, the results of the previous DWA can be 

used for the new uses.

Table 2. Current Maximum Use Pattern for Cyprodinil Based on Vangard® WG (EPA Reg. No. 100-

828), Switch® 62.5G (EPA Reg. No. 100-953) and Inspire Super® (EPA Reg. No. 100-1317) Fungicides

Use

Max. Single 

App Rate

(lb a.i./A)

Number of 

Apps at 

Max Rate

Annual App. 

Rate

(lb a.i./A/yr)

Interval 

Between 

Apps. (days)

App 

Method

Pre-Harvest 

Interval 

(days)

Almond (CA almond) 0.47 3 1.4 NS or 14 (1) G, A* 14

Pistachio 0.33 4 1.3 14 G, A* 7

Tree Nuts [beech nut, Brazil nut, butternut, 

cashew, chestnut, chinquapin, filbert 

(hazelnut), hickory nut, macadamia nut, 

pecan, walnut (black and English)]

0.47 3 1.4 NS (2) G, A* 14

G = ground; A* = Aerial (maximum of two aerial applications allowed)
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The crop that was previously modeled is shaded yellow. There is one (1) crop cycle for tree nuts per year.

(1) For Vangard® WG one application at 5-10% bloom, 50-100% bloom and at petal fall. For Inspire Super® the 

minimum retreatment interval is 14 days and the maximum single application rate is 0.33 lb a.i./A.

(2) Apply when conditions are conducive to disease. It is noted that the supplemental labels for Switch® 62.5WG and 

Inspire Super® do not have this crop group.

Table 3. Proposed Use Pattern for Inspire Super® Fungicide (EPA Reg. No. 100-1317) (the new uses for 

Inspire Super® are shaded gray)

Use

Max. Single 

App Rate

(lb a.i./A)

Number of 

Apps at 

Max Rate

Annual App. 

Rate

(lb a.i./A/yr)

Interval 

Between 

Apps. (days)

App 

Method

Pre-Harvest 

Interval 

(days)

Almond (CA almond) 0.33 4 or 5 1.4 14 G, A* 14

Pistachio 0.33 4 1.3 14 G, A* 7

Tree Nuts Crop Group 14-12 [African 

nut-tree; beechnut; Brazil nut; Brazilian pine; 

bunya; bur oak; butternut; Cajou nut; 

candlenut; cashew; chestnut; chinquapin; 

coconut; coquito nut; dika nut; ginkgo; Guiana 

chestnut; hazelnut (filbert); heartnut; hickory 

nut; Japanese horse-chestnut; macadamia nut; 

mongongo nut; monkey-pot; monkey puzzle 

nut; Okari nut; Pachira nut; peach palm nut; 

pecan; pequi; Pili nut; pine nut; pistachio; 

Sapucaia nut; tropical almond; walnut, black; 

walnut, English; yellowhorn; cultivars, 

varieties, and/or hybrids of these]

0.33 4 1.3 14 G, A* 14

Filberts (Hazelnut) 0.33 4 1.3 14 G, A* 14

Pecans 0.33 4 1.3 14 G, A* 14

G = ground; A* = Aerial (maximum of two aerial applications allowed)

The crop that was modeled is shaded yellow. There is one (1) crop cycle for tree nuts per year.